Download Allium cepa Linnaeus, Lilliaceae

A Plant Monograph
on
Onion
(Allium cepa L.)
Prepared by
Hridaya Shrestha
Roll No. 11/2004
Submitted to
The School of Pharmaceutical and Biomedical Sciences
Pokhara University
Simalchaur, Pokhara, Nepal.
2007
Acknowledgement
I would like to thank Prof. Dr. Purusotam Basnet, the Dean, Faculty of Science and
Technolgy, Pokhara University (PU) who was the first who advise me to utilize my leisure
time on writing a plant monograph. I wish to express my gratitude to Prof. Dr. Natasa Skalko
Basnet, the Programme Director of The School of Pharmaceutical and Biomedical Sciences,
PU for her frequent expressing of interest on the progress of my work on monograph writing.
Special thanks are due to Mr. Hari Prasad Devkota, Teaching Associate, The School of
Pharmaceutical and Biomedical Sceinces, PU for his guidance and support.Thanks are also
due to all the librarian staffs of the Pokhara University Library for their help and providing me
available facilities. I would also like to thank the librarians of Pokhara Forestry Campus,
Tribhuvan University for providing me facilities available there.
Finally I wish to express my warmest and deepest gratitude to my family as well for their
support as for their patience during this work.
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Table of Contents
1. Synonyms and common names .............................................................................................. 5
1.1. Scientific Name: .............................................................................................................. 5
1.2. Local Names.................................................................................................................... 5
1.3. Traditional Names ........................................................................................................... 5
1.4. Language Names ............................................................................................................. 5
1.5. Pharmacopoel Name........................................................................................................ 6
2. Introduction ............................................................................................................................ 6
2.1. Origin............................................................................................................................... 6
2.2. History ............................................................................................................................. 7
2.3. Mythological Importance ................................................................................................ 8
2.4. Social Value .................................................................................................................... 8
2.5. Genetic characters ........................................................................................................... 9
3. Classification .......................................................................................................................... 9
4. Botanical Description/ Habit .................................................................................................. 9
5. Pharamcognostical character and pharmacopoeal standard ................................................. 14
5.1. Macroscopic characters ................................................................................................. 14
5.2. Microscopic characters.................................................................................................. 15
5.3. Identity, purity, strength ................................................................................................ 22
6. Distribution/ Habitat............................................................................................................. 26
7. Cultivation and Harvesting................................................................................................... 27
7.1. Breeding and crop improvement ................................................................................... 27
7.2. Propagation and cultivation........................................................................................... 28
7.3. Disease and Pest ............................................................................................................ 31
7.4. Harvesting and Yield..................................................................................................... 32
7.5. Processing and Storage.................................................................................................. 33
8. Chemical Constituents.......................................................................................................... 33
9. Traditional uses .................................................................................................................... 56
9.1. Traditioanl uses in different countries........................................................................... 56
9.2. Ayurvedic use, Homeopathic use, Cosmetic use, other common uses ......................... 58
10. Clinical Use ........................................................................................................................ 59
11. Pharmacological Action (Animal experiment, cellular experiment, enzymatic experiment)
.................................................................................................................................................. 59
12. Formulation ........................................................................................................................ 73
13. Commercial value............................................................................................................... 74
13.1. Production ................................................................................................................... 74
13.2. Markets........................................................................................................................ 74
13.3. Trade and economic impact ........................................................................................ 74
14. Perspective.......................................................................................................................... 77
14.1. Status ........................................................................................................................... 77
14.2. Patent ........................................................................................................................... 77
14.3. Diagnostic characters .................................................................................................. 78
14.4. Occurrence................................................................................................................... 78
14.5. Taste and Potency........................................................................................................ 78
14.6. Substitutes and Adulterants ......................................................................................... 78
15. Miscellaneous..................................................................................................................... 79
15.1. Herbarium collection................................................................................................... 79
16. References .......................................................................................................................... 80
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Glossary of Botanical terms ..................................................................................................... 85
Glossary of Medical Terms ...................................................................................................... 88
List of Abreevations ................................................................................................................. 90
List of Tables
Table 1: Classification of Allium cepa ....................................................................................... 9
Table 3: Compounds identified in oil of onion ........................................................................ 38
Table 4: FAO Data on Onion ................................................................................................... 75
Table 5: Some other United States Patents related to onion .................................................... 77
List of Figures
Figure 1: Bulb of onion .............................................................................................................. 5
Figure 2: Origin of A. cepa......................................................................................................... 7
Figure 3: Root of onion .............................................................................................................. 9
Figure 4: Onion bulbs............................................................................................................... 10
Figure 5: Longitudinal section (L.S.) of Allium cepa bulb ...................................................... 11
Figure 6: Leaves of onion......................................................................................................... 12
Figure 7: Inflorescence of Allium cepa .................................................................................... 12
Figure 8: Flowers of Allium cepa ............................................................................................. 13
Figure 9: Different parts of onion flower including floral diagram ......................................... 14
Figure 10: Longitudinal section of onion root tip .................................................................... 16
Figure 11: Onion leaf under low power ................................................................................... 18
Figure 12: The outer layer of onion skin.................................................................................. 19
Figure 13: Onion epidermis under high power ........................................................................ 20
Figure 14: Seeds of Allium cepa............................................................................................... 22
Figure 15: TLC chromatogram of Allium cepa ........................................................................ 23
Figure 16: TLC chromatogram of Allium cepa ........................................................................ 23
Figure 17: Treatment of Allum vegetables before TLC-analysis ............................................. 24
Figure 18: TLC analysis of Allium vegetables (Sapogenins) ................................................... 24
Figure 19: TLC analysis of Allium vegetables (Sapogenins) ................................................... 25
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Allium cepa Linnaeus, Lilliaceae
Figure 1: Bulb of onion (URL-1)
1. Synonyms and common names
1.1. Scientific Name: Allium cepa L.
Synonyms:
Allium ascalonicum L.
Allium esculentum Salisb.
Allim porrum cepa Rehb.
Cepa rotunda Dod. (URL-2)
1.2. Local Names
Nepalese Local Names
Bhojpuri: Pyaj
Chepang: Pyaj
Danuwar: Pyaj
English: Onion
Gurung: Pyaj
Lepcha: Ochong
Limbu: Makkhang
Magar: Pyaj
1.3. Traditional Names
Sanskrit Names
Palandu
Tiksnagandha
Rocana
Sudrapriya
Kandarpa
Ulli
Durgandha
Pharada
(Joshi, 2000)
Mooshar: Pyaj
Nepali: Pyaj
Newari: Pyaj
Sunwar: Pyaj
Tamang: Pyaj
Tharu: Pyaj
Tibetan: Btsong, Ri-sgog
(Manandhar, 2002)
Dipana
Durbalasya
Sikhakandu
Sukanda
Sikhamani
Siroratna
Sikhamula
Varhini
Mukhadusana
Krimighna
Rudrasangyaka
Mukhagandhaka
Bahupatra
Visvagandha
Yavanesta
Sikhadhara
1.4. Language Names
Arabic Countries: Basl
Brazil: Onion
China: Hu-tsung
China: Shallot
Egypt: Bassal
Egypt: Onion
5
Nicaragua: Cebolla
Nicaragua: Inyan
Nicaragua: Onion
Nicaragua: Sebuya
Peru: Cebolla
Rodrigues Islands: Oignon
Saudi Arabia: Basl
Tanzania: Kitunguu
Tanzania: Onion
Thailand: Hom khaao
Thailand: Hom yai
Tunisia: I-bsel
Tunisia: Oignon
Turkey: Sogan
USA: Bermuda onion
USA: Onion
USA: Red globe onion
USA: Spanish onion
USA: White globe onion
USA: Yellow onion
USSR: Onion
Vietnam: Cu hanh
Vietnam: Hua phak bua
Vietnam: Khtim
Vietnam: Oignon
West Indies: L’oignon
West Indies: Loyon
West Indies: Madras onion
Yemen: Basal
Europe: Onion
Fiji: Piyaj
Fiji: Piyaz
France: Cepa
France: Cebo
France: Oignon
Greece: Onion
Guatemala: Cebolla
Guyana: Onion
India: Onion
India: Piyaj
India: Pyaz
India: Sibuyas
India: Vengayam
Iran: Onion
Iran: Piaz
Italy: Cepolla
Italy: Cipolla
Japan: Onion
Jordan: Basal
Kuwait: Cepa bulb
Kuwait: Common onion
Kuwait: Onion
Mexico: Cebolla morada
Mexico: Onion
Morocco: Bsal
Nepal: Onion
Nepal: Pyaz
Netherlands: Onion
(Ross, 2001)
1.5. Pharmacopoel Name
Bulbus Allie Cepae (Anonymous, 1999)
2. Introduction
Allium cepa is one of the edible species of a large genus (Allium) consisting of more than 700
species (Burnie et al., 1999). Among the edible Allium, the onion (Allium cepa L.) stands in
the first rank, in the warm- temperate hills of eastern Nepal, followed by garlic (Allium
sativum) and shallot (Allium cepa Aggregatum group) (Gautam et al., 1997).
2.1. Origin
Although the origin remains debatable, the middle Asiatic countries in the region of Iran and
Pakistan are considered the primary centre of origin of onion. The near east Asiatic and
Mediterranean regions are considered to be the secondary centres of origin (Anonymous,
2003).
6
Figure 2: Origin of A. cepa (URL-3)
2.2. History
The onion has been cultivated for over five thousand years and has been used in herbal
medicine and as an indispensable flavoring agent or as a vegetable that is cooked or eaten raw.
The name Onion is derived from the Latin, unio, meaning “one large pearl”, and it is
interesting to note that the Chinese called the Onion the “jewel among vegetable” (URL-4).
The Greek historian, Herodotus, related that nine tons of Gold were spent purchasing
onions to feed the builders of pyramids because the onion was so popular in ancient Egypt,
and the Hebrews complained sorely to Moses that the missed the onion when they departed
Egypt for the Promised Land (URL-4).
Prehistoric remains of cultivated plants are often extremely helpful for reconstructing
their evolution and history. This is especially true for seed crops, but much less so for
vegetable species like onion, which have little chance of long-term preservation. Therefore,
one has to rely mostly upon written records and paintings. Hence, the picture one obtains of
the history of such species is fragmentary, at least for the earlier epochs (URL-5).
Unfortunately, there are no records from the presumed area of primary domestication.
The earliest records come from Egypt, where it was cultivated at the time of the Old
Kingdom. Onions appear as carvings on pyramid walls and in tombs from the third and fourth
dynasties (2700 B.C.) They are frequently depicted on offering tables since the fourth
dynasty. Numerous remains from the era of the Egyptian New Kingdom (since 1580 B.C.)
have been found. It was used for funeral offerings and for embalming and has frequently been
found attached to, or within, mummies. It must have been important in the daily diet of many
people. The biblical records of the Exodus (1500 B.C.), in which the Israelites longed for
onion, leek, garlic, and other foods of Egypt, are well known. From Mesopotamia there is
evidence of cultivation in Sumer at the end of the third millenium B.C. This, together with the
records from Egypt, indicates that the initial domestication began much earlier.
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In India there are reports of onion in writings from the 6th century B.C. In the Greek
and Roman Empires, it was a common cultivated garden plant. Reports from this period
include poetry, beginning with Homer up to the Roman satirist Juvenal. There are botanical
and agricultural books, e.g., Theophrastus, 4th century B.C., and Columella in the first century
A.D. Finally, there is the natural history compendium by Pliny from the 1st century A.D.
which details cultivation, use and history. Pliny and Theophrastus distinguished different
varieties. The Romans cultivated onions in special gardens (cepinae) which had specialized
gardeners (ceparii). It is thought that the Romans took onion north of the Alps.
Different cultivars of onion are listed in garden catalogues from the 9th century A.D.,
e.g., in the famous "Capitulare de villis" from the era of Charles the Great. But the onion
became widespread as a crop in Europe only during the Middle Ages. It is said to have been
introduced in Russia in the 12th to 13th century.
The onion was among the first cultivated plants taken to the Americas from Europe.
Columbus took it to the Caribbean. Later it was several times imported and established in the
early 17th century into what is now the northern U.S. Europeans took the species to East Asia
during the last century. Until now, the indigenous cultivated species of this region, especially
Allium fistulosum, are more widespread there. Medicinal literature exists, e.g., Hippocrates, in
the 5th century B .C. and Dioscorides in the 1st century A.D. who gives a comprehensive
description of medicinal properties (URL-5).
2.3. Mythological Importance
“There once was a great monk who, out of compassion for all sentient beings, was a strict
vegetarian. In fact, he claimed he had never in his lifetime consumed the flesh of any animal.
One lady, deciding to test the monk’s claim, prepared a dish for the monk. She told him it
contained only vegetables, but in fact it contained a small piece of meat. The monk gratefully
accepted the dish and the lady left, believing she had fooled him. However, the monk saw
through her trick, and tossed the dish down to the earth. The next morning he awoke, and
found that the food, embedded in the earth, had sprouted into 2 shrubs: one garlic and one
onion.” This is why Buddhists do not eat garlic and onions.” The above story discusses two
significant prohibitions regarding Buddhist eating customs: that of meat, and that of ‘pungent’
vegetables (URL-6).
Egyptians worshipped it believing that its spherical shape and concentric rings
symbolized eternal life. Onions were even used in Egyptian burials as they believed that if
buried with the dead, the strong scent of onions would bring breath back to the dead (URL-7).
Onion has been used as a charm against evil spirits. It is believed that halved or
quartered onions placed in the home absorb negativity. An onion under pillow is said to give
prophetic dreams. Magical swords and knives are purified by rubbing them with an onion half
(URL-8).
2.4. Social Value
Jains do not eat any root vegetables at all, some strict Hindu vegetarians do not eat onions
(URL-9). Some avoid onion, as they are regarded as rajasic (URL-10). Buddhists do not eat
onions. The reason behind this is already discussed in the mythological importance of onion
(URL-6).
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2.5. Genetic characters
Chromosome number (2n) =16 (Anonymous, 1999). In Allium cepa, there is one pair
of chromosome which, instead of having median fiber-attachment and arms of equal length,
has the fiber attached toward one of end and this shorter arm bears a small satellite (Taylor,
1925). A. cepa will cross with A. fistulosum; the F1 is self sterile but backcrosses are possible;
amphidiploids are partially fertile. Common onions of A. cepa will cross with the shallots of
A. cepa and other forms of A. cepa which have normal flowers (proliferum group varieties do
not produce viable pollen). All ordinary varieties will intercross. No crossing with leek or
garlic (URL-11).
3. Classification
Kingdom
Sub-kingdom
Super division
Division
Subclass
Order
Genus
Species
Table 1: Classification of Allium cepa
Plantae
Tracheobionta
Spermatophyta
Liliopodia
Liliales
Liliaceae
Allium L.
Allium cepa L.
(URL-12)
4. Botanical Description/ Habit
Habit
A perennial herb, strong smelling when crushed (Anonymous, 1999).
Root
Adventitious, fibrous (Ranjitkar, 2003)
Figure 3: Root of onion
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Stem
Underground stem modified into tunicated bulb consisting up reduced stem and axillary buds
surrounded by inner fleshy scale leaves and outer membranous dry scales (Ranjitkar, 2003).
Bulbs are uniform in shape, size and skin color. Shapes ranges from spherical to nearly
cylindrical and include flat and cone like bulbs. Skin variations are considerable as is skin
color, which may be white, yellow, brown, red or purple (Ross, 2001). Stem is up to 100 cm
tall and 30 mm in diameter (Anonymous, 1999).
Figure 4: Onion bulbs
10
Figure 5: Longitudinal section (L.S.) of Allium cepa bulb (URL-13)
Leaf
Radical, alternate, sessile, simple cylindrical, hollow green, parallel veined foliage leaves with
fleshy sheathing base arising from the underground stem (Ranjitkar, 2003). The sheath
develops to encircle the growing point and forms a tube that encloses younger leaves and the
shoot apex. Young leaves grow up through the center of the sheath of the preceding leaf. The
leaf blades are tubular, slightly flattened on the adaxial side, and although hollow are closed at
the tip (Ross, 2001). Leaves are up to 40 cm in height and 20 mm in diameter (Anonymous,
1999).
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Figure 6: Leaves of onion (URL-14)
Inflorescence: The terminal inflorescence develops from
the ring-like apical meristem. Scapes, one to several,
generally elongate well above the leaves and range in
height from 30 cm to more than 100 cm. The scape is the
stem internode between the spathe and the last foloage
leaf. A spherical umbel is borne on each scape and can
range from 2 cm to 15 cm in diameter. The umbel is an
aggregate of flowers at various stages of development;
usually it consists of 200-600 small individual flowers, but
this number can range from 50 to more than 1000 (Ross,
2001).
Figure 7: Inflorescence of
Allium cepa
Flower
Bracteate, 2-3 membranous spathe like bracts enclosing the flower during young stage,
actinomorphic, trimerous, hypogynous, small and white (Ranjitkar, 2003).
12
Figure 8: Flowers of Allium cepa
Perianth
Stellate (Anonymous, 1999), six tepals in two alternate whorls of three each, polyphyllous,
petaloid, white with green midrib, inferior (Ranjitkar, 2003).
Androecium
Six stamens in two whorls of three each, opposite the tepals; antipetalous, polyandrous,
epiphyllous, inferior. Filament- long but slightly dilated at the base. Anther- long, bilobed and
basifixed (Ranjitkar, 2003).
Gynoecium
Tricarpellary, syncarpous. Ovary – superior, trilocular with 2 ovules in each locules, axile
placentation. Style – short and filiform. Stigma – minute (Ranjitkar, 2003).
Fruit
Capsule of about 5 mm (Anonymous, 1999)
Floral Formula:
13
Figure 9: Different parts of onion flower including floral diagram
5. Pharamcognostical character and pharmacopoeal standard
5.1. Macroscopic characters
Underground stem modified into tunicated bulb consisting up reduced stem and axillary buds
surrounded by inner fleshy scale leaves and outer membranous dry scales (Ranjitkar, 2003).
Bulbs are uniform in shape, size and skin color. Shapes ranges from spherical to nearly
cylindrical and include flat and cone like bulbs. Skin variations are considerable as is skin
14
color, which may be white, yellow, brown, red or purple (Ross, 2001). The shape and the size
of the bulb differ with each variety (from 2 to 20 cm, flattened, spherical, or pear-shaped)
(Bruneton, 1999; Anonymous, 1999).
5.2. Microscopic characters
Root
The epidermis consists of small tabular somewhat radially elongate cells in transverse section.
The outer tangential and radial walls are relatively thick and layered at the electron
microscope level. A distinct hypodermis is present under the epidermis which possesses
casparian strips in the primary wall. In the mature state, it is evident in the electron
microscope that each cell is encased with a complex suberin lamella. A cortex is present and
consists of isodiametrically shaped parenchyma cells. The endodermis is distinct and in the
mature form its cells have thick secondary walls. Presumably, as is tree of other
monocotyledons, this wall consists of a suberin lamella covered by layers of lignified
cellulose. This thickening is greatest on the inner tangential walls. The steles can be tetrarch,
pentarch or hexarch but most commonly are pentarch.
The histogens of the onion root tip consist of two distinct groups of initials, one giving
rise to the vascular cylinder or stele, and the other to the cortex, endodermis, and root cap. The
root cap is presumably the site of gravitational perception in roots. In particular, the site
resides in the central column of cells called the columella. The ultrastructural characteristics
of the columella cells are similar. The cells contain large nuclei, amyloplasts, endoplasmic
reticulum, and mitochondria. The positioning of the organelles in the columella of both types
of roots is also the same; amyloplasts (starch grains) are positioned at the gravitational base of
the cells and nuclei at top of the cell away from gravity. However, the size of the columella
cells is smaller in short roots than in long roots. The volume of columella tissue is correlated
with the gravity response.
Roots are continuously formed in distinct rings at regular intervals in the onion stem.
They are formed by the PTM at its more basal level just above the region of the stem where
all tissues are mature. Since the apical meristem is sunken at the shoot tip, this is
approximately at the level of the apical meristem. The vasculature of the root then matures in
connection with that of the stem as well as does the endodermis of the root with the
endodermoid layer in the stem. Therefore, there is a continuous vascular and endodermal
connection between stem and root from root initiation. The root tip grows through stem
cortical tissue and leaf bases to emerge from the plant (URL-2).
15
Figure 10: Longitudinal section of onion root tip (URL-15)
In the cells of the root tip of an onion chromosomes can be made visible quite easily.
They can be seen during various phases of mitosis: the chromosomes in the cell's nucleus
copy themselves (URL-15).
Vegetative stem
The stem of a mature pre-bulbed plant is heart shaped in median longitudinal section. The
apical meristem and youngest leaf primordia are sunken in a "bowl" of surrounding stem
tissue. The stem can be divided into two major regions: the cortex and the central cylinder.
Pith in the center of the central cylinder, directly below the apical meristem, is devoid of
vascular tissue. The central cylinder is congested with vascular bundles and leaf traces. The
vascular bundles are often seen to describe an "S" shape in longitudinal section, approaching
the pith, and then turning out to form leaf traces. In transverse section, the leaf traces are
collateral and the stem bundles are amphivasal in vascular tissue arrangement.
16
In the basal regions of the stem where all cells are mature, the cortex is distinguished
from the central cylinder by boundary zone of three tissues. They are (1) a uniseriate
endodermoid layer of cells with thickened cell walls, (2) a layer of irregularly shaped
parenchyma cells, often called a pericycle, and (3) and congested network of vascular bundles
which form the vascular connection between the stem and roots. If these layers are followed
toward the apex in the stem, they are confluent with a narrow meristematic layer, the primary
thickening meristem (PTM). The PTM runs parallel to the stem outline and separates the
central cylinder from the cortex and meets up with the apical meristem. The PTM consists of
flattened cells which are undergoing rapid cell divisions. The PTM is not only responsible for
stem thickening in onion but also is responsible for root initiation. These anatomical and
histological features are similar in all respects to those in garlic.
The vegetative stem in onion has a very distinctive pattern of cell alignment which is
the result of the pattern of cell division in the PTM. In longitudinal section, the cells are
arranged in distinctive files which run from the leaf bases through the PTM to the pith of the
central cylinder. The files of cells are not continuous across the pith. The arrangement of cells
in the pith is irregular. The files of cells in the stem remain organized during stem growth;
however, their angle varies at different levels of the stem. The files are almost vertically
oriented in the top of the stem near the apical meristem, but more horizontally oriented in the
base of the stem. The leaf traces parallel the cell files at all levels of the stem. In cross section,
the cell files form concentric circles in the top of the stem.
Stem development in onion is similar to that in other monocotyledonous species with a
short, squat stem and a rosette habit. The stem grows in height by the addition of cell files at
the base of the shoot apical meristem. The stem then thickens in width first by increase in
length of the cell files due to cell divisions in the PTM and by subsequent cell enlargement
and finally by reorientation of the cell files toward the horizontal as the tissues reaches
maturity. In conjunction with this, the leaf primordia are initiated at the apical meristem in the
"well" and as they increase in diameter they pass up and over the shoulders at the top of the
stem as the associated stem cell files increase in length, form the shoulders, and finally are
bent away from the vertical (URL-2).
Leaf
Adult Photosynthetic Leaf
Leaves possess a uniseriate epidermis with thickened outer walls with a cuticular layer. The
epidermal protoplasts are highly vacuolate. Stomata are frequent in the epidermis.
Chlorenchyma is present under the epidermis in the form of palisade cells and isodiametric
spongy mesophyll. The chlorenchyma contains abundant intercellular space and chloroplasts
are located almost exclusively along the walls adjoining the air spaces. These cells are also
highly vacuolate. Chloroplasts have a reniform shape, contain highly developed granafretwork systems, and lack starch. Mitochondria and microbodies are present in close
association with the chloroplasts.
Internal to the chlorenchyma and in the interveinal regions there is one type of ground
parenchyma. It has less intercellular space but the characteristics of the chloroplasts are
similar to chlorenchyma except that the chloroplasts are elliptical in shape. Articulated
laticifers occur between the ground parenchyma and the chlorenchyma. The second type of
ground parenchyma is more internal in position and consists of larger cells. Finally, there is a
layer of axially elongate cells which lack protoplasts and line the central lacuna.
The major vascular bundles in the onion leaf are bounded by a uniseriate layer of
compactly arranged bundle sheath cells. These cells are highly vacuolate but do contain many
organelles including spheriodal chloroplasts which contain starch grains. The conducting cells
17
of the vascular bundles are surrounded by vascular parenchyma immediately internal to the
bundle sheath cells. The bundles are collateral. The phloem contains sieve tube elements and
companion cells.
The leaf primordium is initiated on the flanks of the slightly convex apical meristem
and grows erectly as first a rounded and then pointed mound on one side of the apical
meristem. When it is 150-200 mm in length, adaxial meristematic activity initiates the radial
growth responsible for subsequent dilation of the leaf axis. This establishes the boundary
between the sheathing base and the unifacial blade. In transectional view the leaf primordium
arises from the shoot apex as a flattened, bifacial pad which appears somewhat indented along
its adaxial surface. The sheathing base originates as a circumferential expansion of the leaf
primordium entirely around the perimeter of the shoot apex. The sheath then elongates as a
tube. The boundary between the sheathing base and the blade is delineated in the young
primordium by the adaxial ligular outgrowth which is partially epidermal in origin.
Periclinal divisions and enlargement of the central cells in the leaf axis in combination
with adaxial meristematic activity contribute to the increase in thickness in the central portion
of the leaf. Subsequently, the intercalaxy cell division and expansion, and schizogenous
formation of intercellular spaces, result in a more pronounced rounding of the basal section of
the unifacial leaf portion. By contrast with the base, the tip of the leaf does not experience as
much thickening growth, and it retains its flattened form into maturity. The initial phase of
cell enlargement and vacuolation in the onion leaf is expressed along the entire length of the
leaf when it is only 200-300 mm long. Elongation of the central pith cells begins below the
leaf tip and spreads down the length of the unifacial blade. Cells derived from periclinal
division of hypodermal lineages around the periphery of the leaf, especially in the unifacial
zone, will mature as the photosynthetic tissue. These cells are smaller and more densely
staining in the early phases of leaf morphogenesis. Ultimately cell growth in the pith region
fails to keep pace with division and expansion at the leaf's periphery, resulting in the
rhexigenous breakdown of pith tissue and the formation of a central cavity along most of the
blade's length (URL-2).
Figure 11: Onion leaf under low power (URL-16)
Bulb scale
The bulb scale is the organ which is responsible for the food value in onion. It is
morphologically a scale leaf which has an expanded base and an aborted leaf blade. The blade
of the photosynthetic leaf elongates before the base. Since the blade elongates much more
18
than the base, the final leaf ratio (blade/base) is above 5. After transfer to long day, leaf
primordia 1 mm long or less become bulb scales. The blade does not elongate, but the leaf
base elongates earlier and longer than that of the photosynthetic leaf. The final leaf ratio of the
bulb scale is 0.05.
The external dried leaf scales of the bulbs show a large-celled epidermis with lightly
spotted cell walls; the cells are elongated longitudinally. The underlying hypodermis runs
perpendicular to the epidermis and contains large calcium oxalate crystals bordering the cell
walls. The epidermis of the fleshy leaf scales resembles that of the dried leaf scales, and the
epidermal cells on the dorsal side are distinctly longer and more elongated than the epidermal
cells on the ventral side. Large calcium oxalate crystals are found in the hypodermis; stomata
rare; large cell nuclei conspicuous; and spiral vessel elements occur in the leaf mesophyll.
Figure 12: The outer layer of onion skin (URL-17)
19
Figure 13: Onion epidermis under high power (URL-18)
Inflorescence stalk
The anatomy of the inflorescence stalk bears more similarities to that of the leaves than to that
of the vegetative stem. The epidermis is heavily cutinized with sunken stomata and large
accompanying substomatal chambers. The mesophyll has palisade cells to the outside and
spongy cells to the inside. There are two rings of vascular bundles embedded in longitudinally
elongate parenchyma. The outer ring consists of small bundles closely spaced and is
associated with a ring of small parenchyma cells. The bundles are all collateral in vascular
tissue arrangement. Collapsed and broken cells line a central lacuna. The cells are not
arranged in radial files as they are in the vegetative stem and there is no evidence of a
cambial-like zone comparable to the PTM.
At the time of flowering the stem grows up through the ensheathing leaf bases to a
height of about 1 to 2 m. The entire inflorescence between the vegetative stem and the head of
flowers is a single internode. During the transition to flowering, the apical meristem, through
extensive rib meristematic activity, assumes the mantle-core arrangement of cells typical of
floral meristems. The flattened vegetative apical meristem becomes rounded and dome shaped
as rapid longitudinal growth commences. The apex also produces a spathe that subtends the
head of flowers. The spathe is produced immediately after the last vegetative leaf and before
histological evidence of the transition to an inflorescence apex occurs. The inflorescence
subsequently elongates between the last formed vegetative leaf and the spathe. The PTM does
not differentiate into the infiorescence but does into the renewal vegetative bud and maintains
essentially the same histological characteristics as it had in the original vegetative stem.
Sections of later stages of inflorescence growth show that, at the base of the
inflorescence just above the vegetative stem, the cells are small and little tissue differentiation
has occurred. There are many mitotic figures at this level, while approximately 2 cm above
the base of the inflorescence, some differentiation occurs in the protoderm and few mitotic
20
figures are present. Midway up the internode, no mitotic figures are present and much
differentiation has occurred. Finally, at the top of the inflorescence axis the cells are larger
and the greatest amount of differentiation has occurred; the epidermis has stomata; the
palisade layers are developing; and the protoxylem is present. These observations corraborate
the marking experiments and indicate that the inflorescence grows by a basal intercalary
meristem. In onion, at the time of flowering, there is an immediate shift from an emphasis on
growth in width, characteristic of the vegetative phase, to an emphasis on growth in length in
the reproductive phase (URL-2).
Seed
The seed is convex on one side and flattened on the other and is covered by a black seed coat.
The embryo is crescent shaped or curled in a spiral. It consists of a long cotyledon and short
shoot-root axis. The epicotyl consists only of an apical meristem and one leaf primordium.
The epicotyl faces the slit in the base of the cotyledon through which the first true leaf will
emerge during seedling development. The procambium (undifferentiated vascular system)
extends from the root tip to the base of the cotyledon, where it forms a short branch towards
the epicotyl and a long branch which extends the length of the cotyledon. The cotyledon is a
storage organ.
Both the protodermal cells and the internal parenchyma cells store protein in the form
of variably sized protein bodies and lipids in the form of very small lipid bodies. The larger
protein bodies have small light-staining areas which appear as speckles. Undoubtedly, these
consist of phytin crystals (myoinositol hexaphosphate), which are considered to be a storage
form of phosphate in seeds. They are well characterized in other seeds. The cells are thin
walled and intercellular spaces exist between cells. Nuclei are present in each cell. They are
relatively small and irregularly shaped as if they are physically crowded by the protein bodies.
The embryo is buried in a gray, horny endosperm tissue which is the major region of
stored reserves in the onion seed. The endosperm consists of living cells with extremely thick,
hard cell walls. Unlike the cotyledon there are no intercellular spaces between cells. These
walls are not stained with the periodic acid schiffs (PAS) reaction, except for the middle
lamella and the innermost region immediately adjacent to the plasmalemma. The major
carbohydrate in the thickened region of the cell wall is presumably a mannan (ß 1, 4 mannoselinked units as a backbone). The protoplasts are jigsaw puzzle-shaped due to the fact that the
walls are not thickened in regions of pit fields between cells. The cells also store protein in the
form of small evenly sized protein bodies and lipids in the form of very small lipid bodies.
Nuclei are present in each cell. They are large, darkly staining, and relatively spherical in
shape.
The early divisions after fertilization lead to the formation of first a club shaped and
then a spherical embryo attached to a uniseriate suspensor. A slight depression, or notch,
appears on one side which indicates the future position of the shoot apical meristem. The
cotyledon extends greatly in length and produces a marginal sheath-like extention which
creates a depression. Within this depression the apical meristem forms as a mound. It initiates
the first leaf before the seed is mature. The apical meristem of the root becomes organized at
the base of the short hypocotyl. The formation of a lateral notch and the precocious
development of the single cotyledon is similar to embryogenesis in coconut and in grasses
(URL-2).
21
Figure 14: Seeds of Allium cepa (URL-19)
Microscopic characteristics of powdered plant material
Contains mainly thin-walled cells of the mesophyll with broken pieces of spiral vessel
elements; cells containing calcium oxalate crystals are scarce (Anonymous, 1999).
5.3. Identity, purity, strength
General identity tests
Macroscopic inspection, microscopic characteristics and microchemical examination for
organic sulphur compounds; and thin-layer chromatographic analysis for the presence of
cysteine sulphoxides have been found to be useful (Anonymous, 1999).
TLC Chromatograms of Allium cepa
Sulphur and non-sulphur containing constituents have been isolated from Bulbus Allii Cepae;
the sulphur compounds are the most characterstic (Anonymous, 1999).
A.Freshly prepared extracts of Allium cepa (3) (with solvent system of toluene-ethyl
acetate(100:30)show five to seven dark zones in the Range R, range 0.2-0.65 with two
prominent zones of thiosulphinates at Rf 0.3 and Rf 0.45. The dipropylthiosulphinate (T1) at
Rf 0.45 is the characteristic compound of onion extracts. Allicin with almost the same Rf
value is absent. Other thiosuphinates such as dimethylthiosulphinate (T2) at Rf 0.2 are
present, which is contrast to garlic thiosulphinates (TS) show bown-red colours (vis.). This is
partly due to higher TS concentrations and to compounds which overlap the TS as shown in
Fig. 15.
After treatment with the Vanillin-glacial acid reagent (VGA No. 42), the extract of
Allium cepa is distinguishable by the characterstic violet-brown major zones at Rf 0.3 and Rf
0.45, with less concentrated zones at Rf 0.6-0.8. Allicin is seen as a grey-brown-coloured
zone, the sulfides at the solvent front as blue to grey-blue (Fig. 16) zones in the low R, range
of the TLC (Farooq, 2005).
22
Figure 15: TLC chromatogram of Allium cepa
Figure 16: TLC chromatogram of Allium cepa
B. A article (actually this article was on the topic “How to Distinguish Garlic from
other Allium vegetables” whose report was presented at the conference “Recent advances on
the Nutritional Benefits Accompanying the Use of Garlic as a Supplement” held November
15-17, 1998 in Newport Beach, CA) tells us that each Allium vegetables is characteristic and
distinguishable. The detail of chromatographic technique for sapogenin according to this
article is discussed here.
Twenty six different kinds of Allium vegetables were purchased in markets of Japan
and United states. They included Allium sativum L. (garlic), A. ampeloprasum (elephant
garlic), A. ascalonicum, A. canadence, A. cepa (10 different types), A. chinense (Rakkyo), A.
fistulosum (3 different types), A. porrum (leek), A. shoenoprassum (2 dufferent types),
A.tricocum, A.tuberosum, A. victorialis and A. wakegi. Each 10g of vegetables or processed
garlic was crushed in 40 ml of methanol. After removal of the solvent by evaporation, a
suspension of resulting extract in 30% aqueous methanol was applied to a column of MCI gel
23
CHP20P (stepwise elution of 30% aqueous methanol and methanol). The methanol extracts
obtained were hydrolyzed using a mixture of 8% sulphuric acid/ ethanol (1:1) for 5h at 100oC.
The hydrolyzates were added to 20 ml of water and applied to a column of MCI gel, which
was then washed with methanol. The sapogenin fraction from each methanol eluate was
analyzed by TLC.
TLC was performed on a HPTLC Silica gel 60 plate and spots were visualized by
spraying of anisaldehyde –H2SO4 followed by heating of iodine-platinate reagent for sulphur
compounds.
Sapogenin is the agycone of saponin, obtained by hydrolysis of saponin. Twenty-eight
different kinds of Allium vegetables were treated as shown in Figure17. The sapogenin
fractions obtained, corresponding to each vegetable, were analyzed by TLC as shown in
Figure 18 and 19. Each chromatogram of Allium vegetables is characteristic and
distinguishable (Itakura et al., 2001).
Figure 17: Treatment of Allum vegetables before TLC-analysis
Figure 18: TLC analysis of Allium vegetables (Sapogenins)
24
Figure 19: TLC analysis of Allium vegetables (Sapogenins)
Biochemical characterization of landraces through HPLC analysis of endosperm seed
proteins:
Water-, salt-, alcohol- and alkali-soluble seed storage proteins, extracted from 21
white onion landraces (Allium cepa L.), were analyzed by anionic exchange-high performance
liquid chromatography (AE-HPLC). Chromatographic elution profiles of (time range 0-40
min) at 280 nm of water soluble seed proteins evidenced the presence of 21 peaks, which
allowed all the landraces studied to be distinguished from each other. The differences detected
were both qualitative and (presence/absence of one or more peaks) and quantitative; the
water-soluble proteins were useful in differentiating landraces and cultivars while the other
seed protein fractions only showed a weak polymorphism. The cluster analysis, bases on
HPLC data, showed that the landraces clustered with a genetic similarity degree ranging
between 69% and 94%. The possibility of discriminating among closely related onion
landraces during the course of breeding programmes could allow the identification of
biochemical markers linked to useful agronomical traits. As observed by chromatographic
analysis, the globulin composition of onion water-soluble seed protein appears to be
independent of environmental growth conditions. The biochemical characterization of the
available typical onion gremplasm may contribute to obtain a community recognition and
denomination, such as Denomination of Protected Origin (D.O.P.), Indication of Protected
Origin (I.G.P) or Specificity Attestation (A.S.). The biochemical method here developed
resulted of high resolution, cost effective and time-saving for characterization and genetic
purity assessment of the landraces studied (Mennella et al., 2005).
Purity and Strength:
Microbiology: - The test for Salmonella spp. in Bulbus Allii Cepae products should be
negative. The maximum acceptable limits of other microorganisms are as follows.
Preparations for oral use: aerobic bacteria - not more than 105/g or ml; fungi - not more than
104/g or ml; enterobacteria and certain Gram-negative bacteria - not more than 103/g or ml;
Escherichia coli 0/g or ml (Anonymous, 1999).
Total ash
Not more than 6% (Anonymous, 1999)
25
Acid-insoluble ash
Not more than 1.0%, Water-soluble extractive - not more than 5.0% (Anonymous, 1999)
Alcohol-soluble extractive
Not more than 4.0% (Anonymous, 1999)
Pesticide residues
To be established in accordance with national requirements. Normally, the maximum residue
limit of aldrin and dieldrin for Bulbus Allii Cepae is not more than 0.05mg/kg (Anonymous,
1999).
Heavy metals
Recommended lead and cadmium levels are no more than 10 and 0.3mg/kg, respectively, in
the
final
dosage
form
of
the
plant
material
(Anonymous,
1999).
Other purity tests
Chemical, foreign organic matter, and moisture tests to be established in accordance with
national requirements (Anonymous, 1999).
Mineral concentrations of onions (Allium cepa L.) grown under various conditions,
including factors (fertilization, crop year, variety, and provenance) are different. This can help
to develop a technique to determine the geographic origins of onions by mineral composition
(Ariyama et al., 2006).
6. Distribution/ Habitat
Distribution: It is now cultivated throughout the world. Although temperate in origin, it has
been bred to adapt to the tropics (Ross, 2001). It is distributed throughout Nepal to about 3000
m (Manandhar, 2002). They are not found in New Zealand and Australia (Anonymous, 2006).
Habitat:
A. cepa is cultivated under a wide range of conditions. The environmental conditions areLatitude
It can be grown between 60ºS and 60ºN (URL-5).
Temperature
High temperatures encourage bulb formation, but flower formation and seed production are
only possible where the bulbs are subjected to low temperatures. A cool period promotes early
leaf production. Germination temperature is between 15-25ºC, optimal between 20-25. It
grows between 4 and 30ºC, and does not tolerate frost (URL-5).
Water
A long, dry period is required for bulb repening after the leaves have withered. Optimal
rainfall/irrigation requirements are 350-600 mm and it is grown in areas with up to 2800 mm
annual rainfall (URL-5).
Radiation
Range and intensity
It is a sun-loving species (URL-5).
26
Photoperiodism
The production of bulbs is controlled by the photoperiod, the critical day-length varies from
11-16 hours, depending on the cultivar (URL-5).
Soil
Physical
Moist soil is required throughout the growing period, but excessive soil water and high
humidity encourage diseases. Best soils are medium deep, well drained, sandy loams with a
good content of organic matter; it can in also any soil (URL-5).
Chemical
Best soils are medium fertility with low salinity and a pH between 6.0-7.0, but also soils with
low fertility, some salinity and a pH between 4.3-8.3 are feasible (URL-5).
7. Cultivation and Harvesting
7.1. Breeding and crop improvement
Breeding experiments on different varieties of onion showed significance differences
for the all characters studied, viz. leaf length, umbel height, number of seed stalks per plant,
umbel diameter, weight per umbel, 1,000-seed weight, and seed yield per plant. In general, a
character exhibiting a wider range also showed high phenotypic and genotypic coefficients of
variability. High heritability was observed for the number of seed stalks per plant, whereas it
was low for all other characters. The number of seed stalks gave high values for genetic
advance but umbel diameter showed low expectation for genetic gain.
Hybrid vigour or heterosis was observed to the extent of 72 per cent on the average of
the parents, and up to 37 per cent as measured from the better parent. Highly significant
combining ability effects of parents were recorded in the females. For obtaining hybrid vigour
in onions, cytoplasmic male sterility is a useful tool. A 13- 53 cytoplasm which remains
apparently completely stable in performance, is the main source utilized for producing
hybrids. For example, shallot (A. ascalonicum) is easily hybridized with 13-53 (male sterile
cytoplasm) onion because it has the male sterile genes.
For selecting varieties suitable for dehydration the following characterstics are
essential: pale white flesh, small neck and root zones, high pungency, uniform bulb, size of
similar composition throughout, long fresh storage life, high yield potential, high solids
content (15-20%) and also high drying ratio between 3:1 and 20:1.
Selfing and massing method is found to be existed for raising the improved strains of
onion. During the first year, bulbs of desired characters such as uniform size, colour and necks
are planted for obtaining seeds. The umbels are selfed by covering them with muslin cloth
bags and shaking the bags every day to ensure pollination and greater seed-setting. The
progeny of these selfed plants are grown separately, selected for desirable characters and the
selected bulbs propagated and selfed again. This inbreeding for two successive generations
results in homozygosity to a large extent, although the inbred progeny is found to be less
vigorous than the open pollinated original crop. Group breeding in the third generation results
in restored vigour besides the formation of new strains. By following this procedure of
breeding, a number of strains in red, scarlet, and white onions have been evolved
(Anonymous, 2003).
27
7.2. Propagation and cultivation
Onion is important tropical vegetable, grown both as field and garden crop. It is
extensively grown all over India. It is generally grown as irrigated crop throughout the year
though the main planting seasons are June-July and Dec-Jan. In the plains, it is sown during
Oct-Nov and on the hills during March-May. It can not stand heavy rainfall although it can be
grown as a rain-fed crop in certain places. (Anonymous, 2003)
Preparation of land
Onion grown from seed requires a finer degree of tilth than most other vegetables. The soil
should be spread over with decomposed farmyard manure to a depth of 7.5-10.0 cm. Addition
of wood or cowdung ashes and compost has a beneficial effect on the crop. The soil is worked
smooth to a depth of 15-20 cm by repeated ploughing and raking. Beds or ridges with
intervening channels for irrigation are then laid out.
In places where onions are to follow rice, excessive water is drained off by making
treches 6-9 m apart immediately after harvesting the rice crop. The land is worked with a
furrow turning plough and left for drying. Three to four ploughings are given subsequently,
clods broken and pulverized by using a roller. Onions being a shallow feeder, most of the
roots penetrate to a depth of 5.0-7.5 cm and the crop thrives well on a hard bottom
(Anonymous, 2003).
Sowing time
Depending upon the geographical conditions, the sowing time is found to be different in
different places. The bulk of the onion crop is obtained from seed. The seedlings are first
grown in the nursery bed and transplanted in the field later (Anonymous, 2003).
Selection of seed
The viability of the seed is lost in 1-2 years. Good seed is triangular, and black or dark in
colour. The loss of germinating capacity can be detected when the seed looks pale, especially
along the marginal edges. Such non-viable seed is light in weight. About 25 g of normal seed
contains about 7,000 seeds (Anonymous, 2003).
Seed production
Large-sized bulbs (about 7.5 cm in diameter and about 40 g in wt) are selected from the
previous year’s crop and are planted in the field 30 cm apart in rows spaced at 60 cm during
September-October. A furrow 7.5-10.0 cm deep is opened and the bulbs are set in and covered
by hand. Prior to sowing half of the top portion of the bulb results in early sprouting, better
stand, more seed stalks and larger yield of seed. The upper cut portion may be used for edible
purposes.
Onion is a cross-pollinated plant and when the seed production of more than on variety
is required, the varieties should be separated at least by 200 m. Flowering stalks emerge in 10
weeks, and within 6 weeks the seeds ripen. The seed is harvested when the capsules ripen and
the black seeds are seen.
The umbels or seed heads are cut from the stalk and collected. After collection the
seeds are spread on a canvas cloth kept in a well-ventilated, shaded place and stirred once a
day. When thoroughly dried, the seeds are threshed and winnowed clean and dried again
before storing in alkathene in a cool place.
Seed yield per plant is significantly and positively correlated with the number of seed
stalks per plant and the weight per umbel. Seed yield increases with close plant spacing (20
cm), the use of big-sized bulbs (about 50 g) and application of 40 kg N/ha.
28
Onion seed loses its viability after one year; high humidity and high temperature cause
onion to lose its vitality rapidly. Seed viability is enhanced and the associated fungal flora is
eliminated by treatment with Dithan 2-78, Captan, and Brassicol. Onion seed harvested in
May shows 90 per cent germination when sown in Sept.-Oct. Seeds treated with 10 ppm NAA
and 10 ppm IBA gave over 90 per cent and 85 per cent germination respectively as against
about 65 per cent in control (Anonymous, 2003).
Propagation
Ripe onions are generally produced from transplants raised from seeds sown in the nursery
bed 6-8 weeks prior to transplanting, from seeds sown directly in the open field, and by
planting medium-sized mature onion sets (Anonymous, 2003).
Transplanting
The chief advantages of this method are the use of a lower seed rate, early maturation,
formation of large and more uniform bulbs, a better stand, better control of weeds and
ultimately a higher yield. The main disadvantage is the manual labour required.
For the production of healthy seedlings, seed of selected, high yielding varieties
should be sown broadcast, or in drills made 10-15 cm apart in the first week of November or
preferably before the first week of December. Immediately, after sowing the seed is covered 5
cm deep with fine soil mixed with farmyard manure, and a light irrigation given. Irrigation is
repeated every third or fourth day till the plants are well established. The seedlings come up in
a week’s time and are ready for transplanting in 7-9 weeks. Larger seedlings give better yield.
The fields, where the seedlings are to be transported, are divided into small plots of a
convenient size, preferably long and narrow beds, to facilitate weeding and irrigation. The
seedlings are set out in rows about 10 cm apart both ways. Wider spacing for the convenience
of hoeing without provision for adequate plant population, yields bigger-sized onions at the
cost of optimal yield.
Transplanting is done in the first week of January. Seedlings are set 2.5-3.5 cm deep.
Deep planting of seedlings hampers the proper development of bulbs and lowers the yield.
Irrigation is necessary immediately after planting (Anonymous, 2003).
Seed propagation
Onion is also propagated by sowing the seed directly in the field in rows about 30 cm apart.
The seed is dibbled about 1.5 cm deep in heavy soils and about 2.5 cm in sandy soils. For
sowing directly the seed bed is prepared thoroughly and laid out in plots. The rows are marked
and furrows made. The seed is then dropped by hand in the furrows. Coarse sand mixed with
the seed, gives even distribution. A very light irrigation is given immediately after sowing
followed by another after 4-5 days. The seedlings push through the surface in about a week’s
time. When the plants are 6-8 weeks old they are thinned to about 10-12 cm apart. The
thinnings may be transplanted to vacant plots or between other crops, or made use of in a
green state during the course of the season (Anonymous, 2003).
Propagation from dry sets
Onion is also cutivated by planting dry onion sets from the previous year’s crop, which yields
more and matures earlier. The sets are planted in rows 30 cm apart and spaced 10 cm in the
rows. The medium-sized sets of 1.5-2.0 cm in diameter are most desirable for planting. About
14-18 qt of sets is required to plant a hectare.
The dry onion sets are produced by sowing seeds thickly in rows 22-30 cm apart at the
rate of 90-135 kg/ha. Globe-shaped early varieties are chose. The sets are harvested as soon as
29
the crop is ripe and before hot weather sets in. They are pulled out by hand, the tops twisted
off and the bulbs collected and immediately removed to the shade for curing.
The green onions are produced by planting the smallest bulbs from the previous crop
during Sept-Oct in rows 22-30 cm apart and 10 cm apart in the rows. They are usually ready
to be pulled out in 4-5 weeks after planting (Anonymous, 2003).
Manuring
Onion needs moisture-retaining soil rich in available plant food, especially humus. Farmyard
manure or green manure is used freely to maintain a favourable physical condition of the soil.
But the crop does not require much nitrogenous manure which leads to more leaf growth at
the cost of bulbs. Manures rich in potash like wood ash, poultry dropping, etc. give increased
out-turns. Well-rotted farmyard manure is applied at the rate of 25-50 tonnes/ha after the first
ploughing or it may preferably be applied to the preceding crop.
When farmyard manure is used in smaller quantities, application of nitrogenous
fertilizers proves beneficial, but overdoses are detrimental to the keeping quality of the bulbs
and cause the appearance of “scallions” or ‘bull necks’ in a high percentage of the crop. At the
time of the final ploughing, fertilizer at the rate of 250 kg of calcium ammonium nitrate, 250
kg of superphosphate and 125 kg of muriate of potash per hectare is broadcast and mixed well
into the soil. Besides, the crop after transplanting is top-dressed in two split-up doses; the first
dose is given one month after transplanting and the second after three months. Soot and ash
are also used for top-dressing.
Manorial experiments have shown that application of nitrogen, either alone or in
combination with P2O5 and K2O in varying proportions, depending on soil condition, gives
satisfactory results in onion cultivation. Application of 563 kg of calcium ammonium nitrate,
679 kg of superphosphate and 47 kg of muriate of potash per hecatare gave the best results. In
studies on the effect of application of potash and different micronutrient sprays such as zinc,
manganese, and copper on the onion crop, the highest yield was obtained with 281 kg of
potash with copper spray (Anonymous, 2003).
Weeding
Onion needs frequent weeding; the crop is hand-hoed and weeded 20-25 days after planting
and again 3 weeks later. Chemical weed control by using Tenoran (2.0-2.5 kg/ha in 1,000l of
water) after 3-5 weeks of transplanting is very effective and does not affect the yield. Other
weedicides like contact herbicides, etc. are also used (Anonymous, 2003).
Irrigation
Since a steady state moisture supply is required for continuous growth in onion, irrigation is
given once every two weeks during the cool growing period and more frequently when the hot
weather sets in. In all 8-9 irrigations are sufficient for the crop. When the crop is nearing
maturity, it is watered sparingly and when the tops start falling over, irrigation is stopped.
Irrigations should be light, as wetting the soil up to a depth of 30 cm is sufficient for the onion
crop. The drip method of irrigation gives higher yield of the crop (Anonymous, 2003).
Rotation and Intercropping
Rotation is very important for onion crop. It usually follows a heavily manure crop like
potato, which requires a thorough cultivation and leaves the land comparatively free of weeds.
Onion following clovers and cereals thrives well. In irrigated lands, it is rotated with sorghum,
ragi, chillies, rice, etc. in the same year. Depending upon the variety of onion, it is found to be
30
rotated with wheat, bajra, groundnut, vegetables like chillies, potatoes, fodder crops, maize,
etc.
Onion is found to be intercropped with garlic, turmeric, sugarcane, etc (Anonymous,
2003).
7.3. Disease and Pest
Fungi
Leaf diseases
Peronospora destructor, the causal agent of downy mildew is widespread on all continents
(URL-5). The affected parts attain a peculiar colour, and the foliage and the flowering stalks
wither and the bulbs become moist and spongy, thus reducing the yield considerably. Three to
four sprayings with Difolatan was found to be beneficial to reduce the intensity of the disease
and also to increase the net yield of the crop (Anonymous, 2003). Alternaria porri which
causes purple blotch and scald and this is widespread in hot, humid climates as it requires
temperatures of 21-30oC for development. Botrytis allii which causes leaf spot, leaf fleck,
collar rot, brown stain is the common grey mould fungus ubiquitous in temperate regions
(URL-5). The infection usually takes place at curing time, through the exposed moist tissues.
The white varieties, scallions, and injured bulbs are more susceptible than the normal ones.
The lesions on the bulbs appear as sunken dried areas around the neck but may involve the
whole bulb that ultimately rots, giving a stinking smell. The fungus can tide over the winter.
The disease can be controlled by proper rotation and sanitation, elimination of late application
of fertilizers to avoid scallions, clean tillage, rapid curing, close topping, careful handling and
thorough ventilation throughout the storage period. The rotten bulbs should be sorted out and
removed (Anonymous, 2003). Cladosporium allii-cepae causes outbreaks of leaf blotch in
temperate areas. Puccinia allii, causing rust, is widespread but sporadic in temperate zones.
Pleospora herbarum (black stalk mould, leaf spot) occurs in temperate and subtropical parts
of the world. Stemphylium vesicarium, Stemphylium leaf blight, normally invades dying
tissue. Glomerella cingulata (twister disease, anthracnose, seven curls) is more common in the
tropics and subtropics. Cercospora duddiae leaf spot is a tropical disease. The soil bourne
smudge caused by Colletotrichum circinans reduces cosmetic quality on the outer scales
(URL-5).
Root deseases
Pink root, caused by Pyrenochaeta terrestris is present in regions with high soil temperatures.
Fusarium basal rot caused by Fusarium oxysporum is present almost wherever onions are
grown and can cause up to 90% loss of seedlings. Onion smut, caused by the soil bourne
Urocystis colchici and U. cepulae is present in most temperate onion growing regions (URL5). The infected plants become stunted, do not develop bulbs and ultimately die. Onion suffers
heavily from bulb rot, caused by Sclerotium cepivorum. Lower moisture content and an
alkaline soil seem to reduce the intensity of the desease (Anonymous, 2003). Southern blight
is capable of causing serious field and storage losses and is caused by Athelia rolfsii.
Fusarium, Pythium and Rhizoctonia spp. cause damping off (URL-5).
Viruses
Onion Yellow Dwarf Potyvirus (OYDV) is the only important and widespread virus infecting
A. cepa. Others may occasionally infect the common onion (URL-5).
Insects
31
Of the several aphids which attack onion, Myzus ascalonicus is a typical pest of the stored
crop and Myzus persicae damages the growing crop; both are virus vectors. The onion thrips,
Thrips tabaci is widely distributed and is believed to cause more damage to alliaceous crops
than all other pests. Cutworms are major pests of many crops and those which are more
important pests of onion include the larval stages of the turnip moth, Agrotis segetum, Agrotis
ipsilon- the black cutworm and Peridroma saucia- the variegated cutworm.
The almond moth is a cosmopolitan pest of stored products including onion. The leek moth,
Acrolepiopsis assectella also attack onion.
The onion fly or onion maggot, Delia antique is a major pest attacking bulbing and green
onions globally. The bulb fly, Eumerus amoenus is a pest in warmer regions.
Several leaf miners (e.g., Liriomyza sativae and other Liriomyza spp.) colonize onion and are
polyphagous.
Several beetles are important pests of alliaceous crops including flea beetles, chafer beetles,
leaf beetles, weevils and click beetles (URL-5).
Mites
Tetranychus cinnabarius- the carmine spider mite and Tetranychus urticae- the red spider
mite are particularly severe pests locally in many parts of the world. Petrobia latens- the stone
mite may be the most serious onion pest in some parts of the world. The bulb mites,
Rhizoglyphus echinopus and Rhizoglyphus robini are occasionally serious storage pests. The
gall mite- Aceria tulipae occasionally damages onions.
Gastropods
Slugs and snails are troublesome pests of onion- the commonest UK species are Deroceras
reticulatum- the field slug, Arion hortensis- the garden slug and Helix aspersa- the garden
snail (URL-5).
Nematodes
Root parasites: These include the sedentary endoparasites (the root knot nematodesMeloidogyne arenaria, Meloidogyne hapla, Meloidogyne exigua, Meloidogyne incognita,
Meloidogyne javanica and Meloidogyne thanesi) and the sedentary ectoparasite includes the
reniform nematode (Rotylenchus reniformis). Migratory endoparasites include the lesion and
burrowing nematodes (Pratylenchus sp. and Radolphos similes respectively) and the
migratory ectoparasites include the stubby root (Trichodorus sp.), lance (Longidorus sp.) and
dagger (Xiphinema diversichaudatum) nematodes.
Crown parasites: The major crown parasite is the stem and bulb nematodes (Ditylenchus
dipasaci) (URL-5).
7.4. Harvesting and Yield
Harvesting
The green bunching onions are harvested by hand as soon as they attain the required size. The
roots are washed and the outer skin is peeled out leaving the onion clean and white. They are
then tied into bunches and sold.
For the bulb crop, the flower heads are not allowed to set as they affect the formation
of bulbs. The onions are ready for harvest when they are fully mature, which is indicated by
the falling over of the tops while the leaves are still green. When these leaves turn yellow the
onions should be pulled out. Harvesting can be advanced by a process called ‘necking’ in
which the tops of the onions are broken with the help of a plank or the crop is trampled 2-3
times at intervals of a few days. Necking does not affect the yield or the keeping quality of the
32
produce. The bulb crop is ready for harvest in three months after planting. The entire plants
can be pulled out easily from the light soils, but in heavy soils they have to be dug out with
the aid of a sharp-edged hand tool (Khurpa). The tops are cut off 2.5-3.0 cm from the bulbs as
soon as possible after they are removed from the field. The bulbs are then spread out in shade
in thin layers for curing. They are cured for a week or ten days till the necks are completely
dry. A well-cured onion is firm and the top of the bulb is not readily dented with the thumb.
After curing the onions are kept in heaps till they are sent to the market. The small bulbs can
be kept in stacks for two months (Anonymous, 2003).
Yield
The average yield of a transplanted crop varies from 90 to 270 qt/ha. Yields are usually high
when the crop is raised from sets. A seed crop gives c 400-660 kg of seeds per hectare. When
all conditions are optimum it is possible to get yields up to 900 qt/ha (Anonymous, 2003).
7.5. Processing and Storage
Mature onions are cured and dried before storage. They are usually stored by spreading on the
floor or on racks or keeping them in baskets in well-ventilated, thatched sheds or rooms.
Frequent removal of rotted bulbs and loose skins and thinning over of the stored product is
done. Occasionally, they are stored in small thatched pyramids of wheat straw, sorghum straw
or sarkanda constructed in the open on roofs or under shade. This method is probably the
cheapest and the most efficient. Onions can be stored in cold storage at 0.0-2.2º and low
humidity approximately for six months without affecting their pungency (Anonymous, 2003).
The ideal condition of the relative humidity for storage of onions is 70-75% (URL-5).
Heavy losses in onions occur during storage, the chief causes sprouting, rotting,
shrinkage and driage. Sprouting is enhanced by increase in temperature whereas rotting
increases with increase in humidity. Losses are also influenced by varieties, seasonal
variations, stage of harvest of bulb, etc. Onions having a closed neck and tight fitting scales
have better keeping quality. A pre-harvest spray with maleic hydrazide (600 ppm of 40%
maleic hydrazide) considerably inhibits rooting and spoiling during storage. Dipping onions in
a mixture of Fernate and Senesan fungicides and DDT before storing reduces rotting
significantly (Anonymous, 2003). Onions sprayed with maleic hydrazide can not be used for
planting purposes next year, because they will not sprout (URL-5).
8. Chemical Constituents
Bulb
Analysis of the onion (big) gave the following values: moisture, 86.6; protein,1.2; fat,0.1;
carbohydrates,11.1; fibre,0.6; and minerals, 0.4g/100g; calcium ,47.0; phosphorus,50.0;
iron,0.7; thiamine,0.08; riboflavin,0.01; niacin,0.4; and vitamic C, 11.0mg/100g. The
Vitgamic C content decreases on cooking and storage.
The essential amino acid composition of a sample of Indian onion (protein, 1.19%)
was as follows (g/16g N):arginine,2.72; histidine,1.12; lysine,4.64; tryptophan,1.44;
phenylalanine,2.88; methionine, 1.12; threonine, 1.44; leucine, 2.72; isoleucine, 1.44; and
valine, 2.24 (Anonymous, 2003).
The constituents identified are listed below (ppm unless otherwise indicated):
(+)L-S-Prop-1-enyl-cysteine-s-oxide: 25.8
1(F)-beta-fructosyl-sucrose
2-Methyl-but-2-en-1-al
2-Methyl-butyr-2-aldehyde
33
4-Alpha-methyl-zymostenol
4-S-Oxide(trans)dec-2-ene,5-ethyl-4,6,7-Trithia (diastereomer)
4-S-Oxide(trans)dec-2-ene,5-ethyl-4,6,7-trithia
4-S-Oxide(trans/cis)deca-2,8-diene,5-ethyl-4,6,7-thithia (diastereomer)
4-S-Oxide(trans/trans) deca-2,8-diene,5-ethyl-4,6,7-thithia (diastereomer)
4-S-Oxide(trans/trans)deca-2,8-diene,5-ethyl-4,6,7-thithia
6(G)-Beta-fructosyl-sucrose
2,3-Dimethyl-bicyclo(2,2,1)hexane-5-oxide-5,6-dithia(1,2,3,4-alpha-5-beta)
2,3-Dimethyl-thiophene
2,4-Dimethyl-thiophene
24-Methylene cycloartanol
28-Iso-fucosterol
31-Nor-cycloartenol
31-Nor-lanostenol
9,10,13-Trihydroxy-octadec-11-enoic acid
9,12,13-Trihydroxy-octadec-10-enoic acid
Abscisic acid
Acetal
Acetic acid
Adenosine
Allicin
Alliin gamma-glutamyl-peptide
Alliin
Allium cepa polysaccharide
Allyl-propyl-disulfide
Alpha amyrin
Alpha linolenic acid
Alpha-sitosterol
Arabinose
Ascorbic acid
Benzyl-iso-thiocyanate
Beta carotene
Beta-sitosterol
Butane-cis-1-cis-4-dithial-S-S-dioxide,2,3-dimethyl
Caffeic acid
Calcium oxalate
Catechol
Cepaene 1
Cepaene 2-A
Cepaene 2-B
Cepaene 3
Cepaene 4-A
Cepaene 4-B
Cholest-7-en-3-beta-ol
Cholesterol
Choline
Cis-Propanethial-s-oxide
Cis-zweibelane
Citric acid
34
Cyanidin bioside
Cyanidin diglycoside
Cyanidin monoglycoside
Cyanidin-3-O-laminariobioside
Cyclo-(2,1,1)-heptane-5-oxide,cis-2,3-dimethyl-5,6-dithia
Cyclo-(2,1,1)-heptane-5-oxide,trans-2,3-dimethyl-5,6-dithia
Cycloalliin
Cycloartanol
Cycloartenol
Cycloeucalenol
Cysteine
Di-n-propyl-disulfide
Dimethyl-trisulfide
Diphenylamine
DNA
Ethanol
Ferulic acid
Fructose
Gamma-gultamyl leucine
Gamma-glutamyl-S-(Beta-carboxy-Beta-methyl-ethyl)-cysteinyl glycine
Gamma-L-glutamyl cysteine
Gamma-L-glutamyl-L-iso-leucine
Gamma-L-glutamyl-L-valine
Gamma-L-glutamyl-S-(2-carboxy-N-propyl)cysteine
Gamma-L-glutamyl-S-(2-carboxy-propyl)-L-cysteinyl glycine ethyl ester
Gamma-L-glutamyl-S-propenyl cysteine sulfoxide
Glucofructan (Allium cepa)
Glucose
Glutamic acid
Glutathione
Glycine
Glycolic acid
Gramisterol
Iso-quercitrin
Iso-rhamnetin 4’-O-beta-D-glucoside
Iso-rhamnetin
Kaempferol
Kaempferol-3,4’-di-O-beta-D-glucoside
Kaempferol-4’,7-di-O-beta-D-glucoside
Kaempferol-4’-0-beta-D-glucoside
L-2-Propenyl-cysteine sulfoxide
L-Gamma-glutamyl-phenylalanine ethyl ester
L-Gamma-glutamyl-phenylalanine
Gamma-L-glutamyl-L-arginine
L-Methyl-cysteine sulfoxide
Lophenol
Leutein: 0.02
Malic acid
Melatonin: 31.5 pcg/gm
35
Methanol
Methionine methylsulfonium salt
Methionine sulfone
Methionine
Methyl, 1-(methyl-sulfinyl)-propyl-disulfide
Mevalonic acid: 0.5
N-Propyl mercaptan
Nonadecanoic acid
Oleanolic acid
Oleic acid:
Onion coat colorant
Oxalic acid
Palmitic acid
Para-coumaric acid
Para-hydroxybenzoic acid
Pelargonidin monoglycoside
Phloroglucinol carboxylic acid: 100
Phloroglucinol: 100
Prop-cis-enyl-disulfide
Prop-(trans)-enyl propyl-trisulfide
Propan-1-ol
Propane-1-thiol
Propional
Propionaldehyde
Prostaglandin A
Prostaglandin A-1
Prostaglandin B
Prostaglandin E-1
Prostaglandin F
Protocatechuic acid: 0.45%
Pyrocatechol
Pyruvic acid
Quercetin: 0.01-4.8%
Quercetin-3,4’-di-O-Beta-D-glucoside
Quercetin-4’,7-di-O-Beta-D-glucoside
Quercetin-4-di-O-Beta-D-glucoside
Raffinose
Rhamnose
Ribose
Rutin
S-(2-Carboxy-propyl) glutathione: 125mcg/g
S-(beta-carboxy-beta-methyl-L-ethyl)cysteine
S-1-cis-propenyl ester methyl sulfinothioic acid
S-1-Cis-propenyl ester propyl sulfinothioic acid
S-1-Propenyl ester n-propyl sulfinothioic acid(cis)
S-1-Propenyl ester n-propyl sulfinothioic acid(trans)
S-1-Trans-propenyl ester methyl sulfinothioic acid
S-1-Trans-propenyl ester propyl sulfinothioic acid
S-Allyl-cysteine
36
S-Methyl-cysteine sulfoxide
S-N-Propyl ester N-propyl sulphinothioic acid
S-Propyl ester propyl sulfinothioic acid
S-Propyl-cysteine sulfoxide
Satiomem
Sinapic acid
Sodium prop-(cis)-1-enyl-thiosulfate
Sodium prop-(trans)-1-enyl-thiosulfate
Sodium propyl-thiosulfate
Spiraeoside: 1.13%
Stearic acid
Stigmasterol
Succinic acid
Sucrose
Sugars
Thiopropanal-S-oxide
Thiopropional-S-oxide
Valine
Xylitol
Xylose
Zeaxanthin
(Ross, 2001)
When an onion is bruised; the sulphoxides are degraded by allinase and release puruvic acid
and alkyl-thiosulfinates, which rapidly form into disulfides (Bruneton, 1999).
The organic sulphur compounds of Bulbous Allii cepae including the thiosuphinates,
thiosulphonates, cepaenes, S-oxides, S,S’-dioxides, monosulfides, disulphides, trisulfides, and
zwiebelanes occur only as degradation products of the naturally occurring cysteine
sulphoxides (eg. (+)-s-propyl-L-cysteine sulphoxide). When the onion bulb is crushed,
minced, or otherwise processed, the cysteine sulfoxides are released from compartments and
contact the enzyme allinase in adjacent vacuoles. Hydrolysis and immediate condensation of
the reactive intermediate (Sulphenic acids) form the compounds.
The odorous thiosuphonates occur (in low concentrations) only in freshly chopped
onions, whereas the sulphides accumulate in stored extracts or steam-distilled oils.
Approximately 90% of the soluble organic-bound sulphur is present as gamma-glutamyl
cysteine peptides, which are not acted on by allinase. They function as storage reserve and
contribute to the germination of seeds. However, on prolonged storage or during germination,
these peptides are acted on by gamma-glutamyl transpeptidase to form cystine sulphoxides,
which in turn give rise to other volatile sulphur compounds (Breu and Dorsch, 1994).
Essential oil
The bulbs on steam distillation yield an essential oil (0.005%) known as ONION OIL (dα9º,
1.041, [α]D, -0.5º) having an acrid taste and an unpleasant odour. The characteristic odour of
the oil is attributed to the presence of several unstrurated sulphur and other organic
compounds. The alkyl di- and tri-sulphides are primarily responsible for the cooked onion
flavour which is characteristic of steam distilled onion oil. Gas chromatrography of the steam
distilled onion oil showed the presence of several flavour constituents (Table 2). Other
compounds identified are cepanone, nor-cepanone and neodecanoic acid. A lachrymatory
principle, thiopropanal-S-oxide, is also present.
37
Table 2: Compounds identified in oil of onion
Thiophene dervatives
Monosulphides
2,5-Dimethylthiophene
Dimethyl sulphide
2,4-Dimethylthiophene
Allyl methyl sulphide
3,4-Dimethylthiophene
Methyl propenyl sulphide (2 isomers)
3,4-Dimethyl-2,5-dihydrothiophen-2Allyl propyl sulphide
one
Propenyl propyl sulphide (2 isomers)
Dipropenyl sulphides (3 isomers)
Trisulphides
Dimethyl trisulphide
Methyl propyl trisulphide
Oxygen compounds
Propanal
Allyl methyl trisulphide
Dimethylfuran
Methyl cis-propenyl trisulphide
2-Methylpentanal
Methyl trans-propenyl trisulphide
2-Methyl-pent-2-enal
Diisopropyl propyl trisulphide
Tridecan-2-one
Isopropyl propyl trisulphide
5-Methyl-2-n-hexyl-2,3-dihydrofuran-3Dipropyl trisulphide
one
Allyl propyl trisulphide
Diallyl trisulphide
Disulphides
cis-Propenyl propyl trisulphide
Dimethyl disulphide
trans-Propenyl propyl trisulphide
Methyl propyl disulphide
Allyl methyl disulphide
Thiols
Methyl cis-propenyl disulphide
Hydrogen sulphide
Methyl trans-propenyl disulphide
Mehanethiol
Isopropyl propyl disulphide
Propanethiol
Dipropyl disulphide
Allylthiol
Allyl propyl disulphide
cis-Propenyl propyl disulphide
Tetrasulphide
trans-Propenyl propyl disulphide
Dimethyl tetrasulphide
Diallyl disulphide
Allyl propenyl disulphide ( 2 isomers)
Dipropenyl disulphide (3 isomers)
(Anonymous, 2003)
Root
Caffeic acid
Ferulic acid
Gibberellin A-4
Para-hydroxybenzoic acid
Tuliposide A
Tuliposide B
(Ross, 2001)
Leaf and Flower
The leaf and flower from Japan on steam distillation yielded an essential oil (0.006%). The oil
contain two new cyclic cis- and trans-3,5-diethyl-1,2,4-trithiolanes (Anonymous, 2001). The
flower also contains carotene. The other compounds identified as constituents of leaf are as
follows:
Ascorbic acid
38
Caffeic acid
Citric acid
Ferulic acid
Fructose
Glucose
Malic acid
Methanol
Oxalic acid
Para-coumaric acid
Para-hydroxybenzoic acid
Propionaldehyde
Protocatechuic acid
Raffinose
Sinapic acid
Succinic acid
Sucrose
(Ross, 2001)
The presences of quercetin, sterol glycosides are reported. The presence of gibberllin
is also reported.
Analysis of onion stalks gave the following values:moisture, 87.6;protein, 0.9; fat, 0.2;
fibre, 1.6; carbohrdrates, 8.9; and minerals, 0.8g/100g; calcium, 50.0; phosphorus,50.0;
iron,7.5; riboflavin, 0.03; niacin, 0.3; and vitamin C,17.0 mg/100g. The carotene content is
595mg and calorie value, 41 Kcal/100g (Anonymous, 2003).
Skins
Dried onion skins are the best natural source of quercetin. The skin of the pink onion cotains
stigmasterol, cholesterol, β-sitosterol, kaempferol, quercetin, and quercetin-3-glucoside. The
phenolic acids reported to be present are p-hydroxy-benzoic acid, protocatechuic acid and
vanillic acid. The onion skin is also used in the preparation of pectic substances (11-12%) as
reported in the skin of white onion (Anonymous, 2003).
Seed
5-Dehydroavenasterol
Beta-sitosterol
Beta-tocopherol
Brassicasterol
Cholesterol
Fixed oil (17.3-18.1%)
Stigmast-7-en-beta-ol
Trigonelline
Tseposide A
Tseposide B
Tseposide C
Tseposide D
Tseposide E
Tseposide F
(Ross, 2001)
The seed yield an oil (18%) (Anonymous, 2003) with following composition (ppm
unless otherwise indicated):
39
Alpha-tocopherol
Arachidic acid
Eicosen-1-ol
Hexadecen-1-ol
Linoleic acid (57.5-59.1%)
Myristic acid
Oleic acid (26.29%)
Palmitic acid (7.3%)
Stearic acid (3.5%)
Stigmasterol
(Ross, 2001)
H
O
2-Methyl-but-2-en-1-al
O
2-Methylpentanal
CH3
CH3
S
2,3-Dimethyl-thiophene
S
2,4-Dimethylthiophene
S
2,5-Dimethylthiophene
S
3,4-Dimethylthiophene
O
HO
O
O
HO
Abscisic acid
OH
Abietic acid
40
HO
O
N
O
OH
H2N
OH
N
Acetic acid
S
N
HO
N
Adenosine
S
S
Allyl methyl disulphide
Allyl methyl sulphide
S
S
S
S
Allyl propenyl disulphide
Allyl methyl trisulphide
S
S
S
Allyl propyl disulphide
Allyl propyl sulphide
S
S
S
S
Allyl propyl trisulphide
Allyl-methyl-disulfide
S
S
S
Allyl-propyl-disulfide
S
S
Allyl-propyl-sulfide
HS
S
S
Allyl-propyl-trisulfide
Allylthiol
41
O
OH
H
H
HO
H
Alpha linolenic acid
Alpha amyrin
S
S
O
Allicin
Alpha-sitosterol
O
OH
O
OH
H2N
OH
OH
O S
OH
Arabinose
alpha-D-Pyranose form
Allin
O
O
OH
HO
N
OH
HO
C
S
Benzyl-iso-thiocyanate
Ascorbic acid
42
Beta carotene
OH
HO
O
HO
Beta sitosterol
Caffeic acid
OCa
OH
O
O
OCa
Calcium oxalate
OH
Catechol
O
O
Cepanone
43
HO
Cholesterol
HO
Cholest-7-en-3-beta-ol
H3C
+
S
O
Cis-Propanethial-s-oxide
O
OH
OH
OH
O
OH
N
OH
O
Citric acid
Choline
44
OH
OH
OH
O
OH
OH
O
HO
O
OH
OH
Cyanidin 3-glucoside
OH
OH
HO
HO
OH
O
HO
OH
OH
O
O
OH
O
OH
OH
Cyanidin-3,5-diglucoside
45
OH
OH
OH
OH
O
OH
OH
O
O
OH
O
HO
O
OH
OH
Cyanidin 3-laminariobioside
O
OH
NH
S
O
Cycloallin
HO
Cycloartenol
46
HO
Cycloeucalenol
OH
Cycloartanol
CO2H
HS
S
S
Diallyl disulphide
NH2
Cysteine
S
S
S
Diallyl trisulphide
S
S
Dimethyl disulphide
S
S
S
S
Dimethyl tetrasulphide
S
Dimethyl sulphide
S
S
S
S
Dimethyl trisulphide
S
Dimethyl-disulfide
S
S
S
S
Dipropyl trisulphide
S
Dipropyl disulphide
47
HO
Ethanol
COOH
O
HO
O
OMe
OH
Ferulic acid
(E)-form
HO
Ferulic acid
CH2OH
O
CH2OH
O
OH
OH
OH
OH
OH
OH
OH
Fructose
alpha-D-Pyranose form
OH
Galactose
alpha-D-Pyranose form
CH2OH
OH
O
O
OH
OH
HO
OH
OH
Glucose
alpha-D-Pyranose form
O
O
Gibberllin A-4
48
OH
H2N
HO
O
HN
O
HS
O
Glutamic acid
O
O
HN
OH
NH2
O
OH
Glutathione
OH
OH
O
O
NH2
Glycine
OH
Glycolic acid
OH
Gramisterol
S
S
Isopropyl propyl disulphide
O
S
S
S
Isopropyl propyl trisulphide
OH
OH
O
HO
O
OH
O
OH
HO
O
HO
OH
Iso-rhamnetin
Kaemferol
49
OH
Lophenol
H NH2
S
H3C
CO2H
H NH2
O
S-Propyl-cysteine sulfoxide
S-Allyl-cysteine
O
CO2H
S
OH
O
OH
HO
HO
O
Malic acid
Stearic acid
H
N
H
N
O
O
SH
Methanthiol
Melatonin
S
NH2
OH
HO
Methanol
Methionine
50
O
O O
S
S
S
NH2
Methyl propenyl sulphide
HO
O
Methionine sulphone
S
S
S
S
Methyl propyl trisulphide
S
Methyl propyl disulphide
OH
OH
O
OH
OH
O
Mevalonic acid
Nonadecanoic acid
OH
O
HO
Oleanolic acid
O
OH
OH
O
O
OH
Oxalic acid
Oleic acid
51
CO2H
HO
O
OH
Para-coumaric acid
Palmitic acid
O
OH
HO
Para-hydroxybenzoic acid
OH
O
HO
OH
O
O
OH
O
OH
HO
OH
Peonidin-3-glucoside
HO
OH
OH
Phloroglucinol
52
CO2H
HO
OH
Prostaglndin E-1
OH
HO
O
OH
Protocatechuic acid
O
Propanal
OH
HO
OH
O
O O
Pyruvic acid
Tautomeric structures
53
OH
O
OH
HO
O
OH
OH
Quercetin
OH
HO
OH
O
OH
O
OH
HO
O
HO
HO
O
O
OH
HO
OH
Raffinose
O
CH3
O
OH
OH
OH
OH
OH
OH
OH
OH
Ribose
alpha-D-Pyranose form
Rhamnose
alpha-D-Pyranose form
54
OH
HO
HO
OH
O
O
OH HO
OH
O
O
O
OH
O
HO
OH
Rutin
O
O
H3C
OH
OH
O
CO2H
H NH2
O
S-Methyl-cysteine sulfoxide
Sinapic acid
O
OH
OH
O
Succinic acid
HO
Stigmasterol
55
OH
OH
HO
O
HO
OH
O
O
H2N
OH
OH
HO
OH
O
Valine
Sucrose
O
OH
HO
OH
OH
HO
Xylitol
OH
OH
OH
Xylose
alpha-D-Pyranose form
OH
OH
HO
Zeaxanthin
S
S
O
Zwibelene
9. Traditional uses
9.1. Traditioanl uses in different countries
Arabic countries. The dried bulb is used orally as a contraceptive, externally as a liniment, as
an emmenagogue in the form of Unani medicine.
Brazil. Hot water extract of the onion bulb is taken orally to treat hypertension or to induce
diuresis.
Egypt. The roasted bulb is used intravaginally as a contraceptive, before and after coitus.
Europe. The bulb is taken orally to induce menses.
56
Fiji. Fresh bulb juice is applied ophthalmically to improve eyesight; aurally for earache (juice
warmed with coconut oil is dropped in the ear). The fresh bulb is eaten raw with salt for
stomachache.
Germany. Fresh bulb juice is used externally as an anti-inflammatory agent on insect bites
and for bronchitis. Hot water extract of the bulb is taken orally to induce miscarriage.
Greece. Warm bulbs are applied externally to treat furuncles.
Guatemala. Hot water extract of the dry bulb is used externally for wounds, ulcers, bruises,
sores, skin diseases, irritations and eruptions, erysipelas and burns.
India. The bulb is taken orally as an emmenagogue. The hot water extract is taken orally by
women as an emmenagogue. Butanol extract of the bulb is taken orally for asthma. Hot water
extract of the bulb is taken orally by men and women as an aphrodisiac. Butanol extract of the
bulb is taken orally as an expectorant and diuretic. The dried seed is used as an abortifacient;
parts of the seed, 3 parts of Punica granatum root, 2 parts of Cajanus cajan and red lead oxide
are taken with honey. For abortion, the vaginal region is fumigated with feces of wild pigeon
and seeds of Allium cepa. Hot water extract of the seed is taken orally as an emmenagogue.
Fresh fruit juice, mixed with the juice of Achyranthes bidentata leaves is taken orally every 2
hours for cholera. Hot water extract of the fresh bulb is taken orally for diabetes, dysentery
and fever. The leaf juice is administered ophthalmically to treat jaundice.
Italy. The bulb is taken orally for menstrual and uterine pains. Decoction of the dried shoot is
taken orally as a cicatrizing agent and to treat insect bites. Hot water extract of the dried bulb
is used for inflammation. The decoction is used externally as a cicatrizing agent. The raw bulb
is eaten to improve eyesight. Wine extract of the fresh bulb is taken orally for renal function
and urinary disease; externally it is used for boils and whitlows. The bulb is eaten for
gastronomic purposes.
Japan. The fresh bulb is used as a regular part of the diet.
Kuwait. The bulb is taken orally as an emmenagogue and aphrodisiac.
Malaysia. The bulb is taken orally for amenorrhea.
Mexico. Decoction of the dried leaf, together with Pimpinella anisum and Allium sativum, is
given orally to new born infants. The root is taken orally to facilitate expulsion of the
placenta.
Nepal. The fresh bulb is taken orally for tuberculosis. Five hundred grams of the leaf of
Adhatoda vasica is decocted in 5 liters of water until a dark brown mass remains. Half a
teaspoonful of this drug is taken with honey and 10 grams Allium cepa twice daily for 6
months.
Nigeria. The fresh bulb is taken orally as a carminative, tonic, antipyretic, hypotensive and
diuretic.
Peru. Hot water extract of the fresh bulb taken orally to regulate blood pressure, dropsy,
urinary problems, renal and biliary calculi, bronchitis and as an antidiabetic. Externally, the
extract is used for acne.
Philippines. Butanol extract of the dried bulb is taken orally to treat high blood pressure.
Saudi Arabia. Hot water extract of the fresh bulb is taken orally for diabetes, dropsy, colic,
catarrh, chronic bronchitis, scurvy, body heat, epilepsy, hysterical fits, nosebleed, jaundice,
unclear vision, spleen enlargement, rheumatic pain and strangury. Hot water extract of the
dried bulb is taken orally for diabetes, dropsy, colic, catarrh, chronic bronchitis, scurvy,
epileptic fits, hysterical fits, epistasis, jaundice, enlarged spleen; rheumatic pain and
strangury.
Thailand. Fresh bulb essential oil, administered by inhalation, is used for the treatment of
colds. The bulb is taken orally for gastrointestinal infections.
57
Tunisia. The dried bulb is taken orally as an antiphlogistic, and is applied externally to treat
infections.
USA. The fresh bulb is taken orally as a sedative, blood purifier and expectorant.
Vietnam. The bulb is taken orally as an emmenagogue.
West Indies. Bulb juice with sugar is given to children for worms.
Yemen. Hot water extract of the plant is used medically.
Yogoslavia. Hot water extract of the fresh bulb is taken orally for diabetes.
(Ross, 2001)
9.2. Ayurvedic use, Homeopathic use, Cosmetic use, other common uses
Ayurvedic properties
Rasa - Madhura, Katu.
Virya - Usna.
Guna - Guru, Snigdha, Tiksna
Vipaka – Madhura
(Joshi, 2000)
Actions/Uses
Vatasamaka, Kaphapottavardhaka, Tvagrogahara, Vedanasthapana, Dipana, Pacani, Balya,
Medhya, Rasayana, Rocana, Anulomana, Sosaghna, Kustaghna, Sophaghna, Arshoghna,
Yakrtottejaka, Svaraprada, Caksusya, Vrsya, Varnakara, Bhaghnasandhakara, Hrdrogahara,
Ajirnanasana, Jvaraghna, Krimighna, Gulmahara, Kuksisulahara, Vibandaghna, Kasaghna,
Svasaghna (Joshi, 2000).
Cosmetic uses
Onion juice rubbed into the skin is said to promote the growth of hair and to be a remedy for
baldness. It is also used as a cosmetic to get rid of freckles (URL-20). Onion extract was
found to be useful in prevention of scarring in patients having laser removal of tattoos (Ho et
al., 2006).
Homeopathic use
Allium cepa, better known as Cepa is a Homeopathic remedy. Coryza profuse, watery and
acrid nasal discharge; with profuse bland lachryrmation is typical symptom. Acute catarrhal
inflammation of mucus membranes with increased secretion; eyes burning, biting smarting as
from smoke, must rub them are other symptoms of note (Joshi, 2000).
Other common uses
The juice of the plant is used as a moth repellent and can also be rubbed onto the skin to repel
the insects. The plant juice can be used as a rust preventative on metals and as a polish for
copper and glass. A yellow-brown dye is obtained from the skins of the bulbs. The growing
plant is said to repel insects and moles. A spray made by pouring enough boiling water to
cover 1 kg of chopped unpeeled onions is said to increase the resistance of other plants to
diseases and parasites (URL-20). Allium cepa root length inhibition test is a well
recommended bioassay for the evaluation of the toxicity of various polluted waters. Allium
cepa derived EROD (7-ethoxy resorufin O-deethylase) can act as a potential biomarker of
certain pesticides present in water (Fatima and Ahmad, 2006). The possibility of producing a
new type of vinegar from worthless onions, which fail to meet the quality standards required
for marketing, was investigated. Several kinds of onion were initially tested as raw material
58
for vinegar production, and vinegar was successfully produced from the juice of a red onion,
the cultivar Kurenai, by batch culture using yeast and Acetobacter aceti. Nutritional analysis
revealed that the potassium content of onion vinegar was extremely high, while the amount of
sodium was lower than that in conventional vinegars. It was also shown that the total amino
acid and total organic acid contents of the onion vinegar were respectively 1.6-6.9 times and
3.5-11.5 times those in other kinds of vinegars (Horiuchi et al., 1999).
10. Clinical Use
It has been shown that Allium species may help to prevent tumor promotion, cardiovascular
diseases and aging; all processes that are associated with free radicals (Stajner et al., 2006).
Uses suported by clinical data
The principle use of Bulbous Allii Cepae today is to prevent age-dependent changes in the
blood vessels, and loss of apetite (Anonymous, 1999).
Uses described in pharmacopoeias and in traditional systems
Treatment of bacterial infections such as dysentery, and as a diuretic. The drug has also been
used
to
treat
ulcers,
wounds,
scars,
keloids,
and
asthma.
Bulbus Allii Cepae has also been used as an adjuvant therapy for diabetes (Anonymous,
1999). The Chinese pharmacopeia indicates its use for treatment of angina pectoris, cough,
and dyspnea (painful, difficult breathing), and also tenesmus (painful spasmodic contraction
of anal or vesical sphincter) in dysentery (Anonymous, 1997).
Uses described in folk medicine, not supported by experimental or clinical data
As an antihelmintic, aphrodisiac, carminative, emmenagogue, expectorant, and tonic , and for
the treatment of bruises, bronchitis, cholera, colic, earache, fevers, high blood pressure,
jaundice, pimples, and sores (Anonymous, 1999). The juice made into syrup is good for colds
and coughs (Biswas, 2006).
11. Pharmacological Action (Animal experiment, cellular experiment, enzymatic
experiment)
Abortifacient effect. Ethanol/ water (1:1) extract of the seed, administered orally to female
rats at a dose of 200.0 mg/kg, was inactive (Prakash et al., 1976).
Acid phosphatase inhibition. Water extract of the fresh bulb and the fresh bulb, administered
intragastrically to rats, were active on RBC (Ahluwalia and Mohindroo, 1989).
Adenosine deaminase inhibition. Sap of the fresh bulb, at a concentration of 10.0
microliters, was inactive (Kock et al., 1992).
Aflatoxin production inhibition. Water extract of the fresh bulb, at a concentration of the
fresh bulb, at a concentration of 1.0 mcg/ml, was active on Aspergillus flavus. Aflatoxin B-1
production was inhibited 44.80%. On agar plate, a concentration of 250.0 mcg/ml was active.
Aflatoxin B-1 prodcution was inhibited 60.44% (Ross, 2001).
Alanine racemase inhibition. Lyophilized extract of the fresh bulb, in the ration of chicken
at a concentration of 2.0% of the diet, was active. Cu-Zn superoxide dismutase activity was
inhibited (Ross, 2001).
59
Alkaline phosphatase inhibition. Water extract of the fresh bulb, in the ration of rabbits at a
concentration of 20.0% of the diet, was active. The study was conducted for 6 months in
cholesterol-loaded animals. Water extract of the fresh bulb and the fresh bulb, administered
intragastrically to rats, were active on RBC (Ross, 2001).
Alkaline phosphatase stimulation. The fresh bulb, in the ration of rats at a concentration of
3.0% of the diet, was inactive (Ross, 2001).
Alpha amylase inhibition. Water extract of the fresh bulb was active (Ross, 2001).
Analgesic activity. Ethanol (70%) extract of the fresh bulb, administered intraperitoneally to
mice of both sexes at variable dosage levels, was active (Ross, 2001).
Antifungal activity and antibacterial activity. An aueous extract of the juice of Bulbous
Allie Cepae inhibited the in vitro growth of Escherichia coli, Streptococcus species
(Anonymous, 1999; Arunachalam, 1980), Lactobaccilus odonotlyticus, Pseudomonas
aeruginosa, and Salmonella typhosa (Anonymous, 1999). The fresh bulb, on agar plate, was
inactive on Escherchia coli and Staphylococcus aereus, MIC 7.5 mg/ml. The chloroform
extract was inactive on Escherchia coli and Staphylococcus aureus, MIC >6.0 mg/ml (Hughes
and Lawson, 1991). A petroleum ether extract of Bulbous Allii Cepae inhibited the in vitro
growth of Clostridum paraputrificum and Staphylococcus aureus. The essential oil has
activity against a variety of fungi including Aspergillus niger, Cladosporium verneckii,
Candida albicans, Fusarium oxyparum, Saccharomyces cervisiae, Georichum candidum,
Brettanomyces anomalus, and Candida lipolytica (Anonymous, 1999). The fresh bulb, on agar
plate was active on Nannizzia fulva, Nannizzia gypsea and Nannizzia incurvata (Singh and
Desmukh, 1984).
Antianaphylactic acitivty. Ethanol (95%) extract of the bulb, administered intraperitoneally
to guinea pigs at a dose of 50.0 mg/kg, was active vs egg albumin sensitization (Ross, 2001).
Antiascariasis activity. Water extract of the bulb, at a concentration of 10.0 mg/ml, was
active on earthworms (Ross, 2001).
Antiasthmatic activity. Ether extract of the fresh bulb, administered intragastrically to guinea
pigs at a dose of 100.0 mg/kg, was active vs allergen- induced asthmatic reactions and platelet
activating factor-induced asthmatic reactions, and inactive vs histamine-induced asthmatic
reactions and acetylcholine-induced asthmatic reactions (Ross, 2001). Ethanol (95%) extract
of the fresh bulb, administered by gastric intubation to guinea pigs at a dose of 1.0 ml/animal,
was active vs allergen-induced bronchial asthma. Results significant at p<0.02 level. The
extract was inactive vs histamine- and acetylcholine-induced bronchial asthma.The water
extract was inactive vs allergen-induced bronchial obstruction. Results significant at p<0.05
level ( Dorch et al., 1985).
Anticholesterolemic acitivity. Water extract of the fresh bulb, in the ration of rabbits at a
concentration of 20.0% of the diet, was inactive. The study was conducted for 6 months in
cholesterol-loaded animals. The fresh bulb, administered orally to rabbits, was active.
Hypercholesterolemic rabbits that were fed a cholesterol and onion extract diet had a lower
level of total lipids, cholesterol and phospholipids in the eyes than those fed only cholesterol.
This level was similar to the control group (Ross, 2001).
60
Anticlastogenic activity. Bulb juice, administered intragastrically to mice at a dose of 25.0
ml/kg, was active on bone marrow cells vs mitomycin C-, dimethylnitrosamine-, and
tetracyline-induced micronuclei (Ross, 2001).
Anticonvulsant activity. Ethanol (70%) extract of the fresh bulb, administered
intraperitoneally to mice of both sexes at variable dosage levels, was active vs metrazole- and
strychnine-induced convulsions (Ross, 2001).
Anticrustacean activity. Ethanol (95%) extract of the dried bulb was inactive on Artemia
salina. The assay system was intended to predict for antitumor activity (Ross, 2001).
Antiedema activity. Methanol extract of the bulb, applied on the ears of mice at a dose of 2.0
mg/ear, was active vs 12-0-tetradecanoylphorbol-13-acetate (TPA)-induced ear inflammation.
Inhibition ratio (IR) was 15 (Ross, 2001).
Antifertility effect. Hot water extract of the dried bulb scales, at a concentration of 20% in
the drinking water, and administered intraperitoneally at variable dosage levels, was equivocal
in pregnant mice (Ross, 2001).
Antifilarial activity. The fresh bulb was active on Setaria digitata, LC100 700 ppm (Ross,
2001).
Antihistamine activity. Ethanol extract (95%) of the bulb, administered orally to guinea pigs
at a dose of 200.0 mg/kg, and intraperitoneally at a dose of 50.0 mg/kg, was active vs
histamine aerosol (Ross, 2001).
Antihypercholesterolemic activity. The bulb juice, administered orally to rabbits, was
active. The animals were fed a high cholesterol diet and the juice of 25 gm of onion/kg of
body weight daily for 16 weeks. Ethanol (95%) extract of the fresh bulb, administered by
gastric intubation to rabbits at a dose of 20.0 gm/animal, was inactive. Cholesterol-loaded diet
was used daily for 3 months. The onion extract appeared to prevent crenation and aggregation
of RBC. The essential oil, administered by gastric intubation to rats at a dose of 100.0 mg/kg
for 60 days, was active vs ethanol-induced hyperlipemia. Results siginificant at p<0.01 level.
The fixed oil, in the ration of male rats at a dose of 100.0 mg/kg, was active. Simultaneous
feeding of unsaturated oil from the plant material with a high sucrose diet significantly
reduced serum and tissue cholesterol levels, and a small but significant tissue-protein reducing
effect was also observed. The outer skin fiber, in the ration of male rats at a dose of 263.0
gm/day, was active. Scales of bulb, at a dose of 5.0 mg/kg for 45 days, was active (Ross,
2001).
Antihyperglycemic activity. Decoction of the fresh bulb, administered intragastrically to
mice at a dose of 0.5ml/animal, was active. Twenty-five percent aqueous extract was used and
produced a maximal change in blood sugar of 28.2% vs alloxan-induced hyperglycemia.
Ethanol (95%) extract of the bulb, at a dose of 250.0 mg/kg, was active in rabbits vs alloxaninduced hyperglycemia. A 18.57% drop in blood glucose was observed at 2 hours posttreatment. Ether and ethanol (95%) extracts of dried bulb, var. Behairy, administered by
gastric intubation to rats at a dose of 50.0 gm/kg (expressed as dry weight of the bulb), were
active vs alloxan- and epinephrine induced hyperglycemia. Ether extract of the aerial part,
61
administered subcutaneously to rats at a dose of 0.5 ml/animal dailt for 10 days, was
equivocal vs alloxan-induced hyperglycemia. The plant juice produced weak activity. Ether
extract of the fresh bulb, administered intragastrically to rabbits at doses of 100 mg/animal for
7 days, and 250 mg/kg, was active vs alloxan-induced hyperglycemia. Water extract of the
fresh bulb, taken orally by human adults at a dose of 100.0 gm/person, was active vs glucoseand adrenalin-induced hyperglycemia. Fresh bulb juice, administered intragastrically to
rabbits at a dose of 25.0 gm/animal (expressed as dry weight of plant), was active vs glucoseinduced hyperglycemia. Petroleum ether extract of the fresh bulb, administered
intragastrically to rabbits at a dose of 250.0 mg/kg, was active vs alloxan-induced
hyperglycemia. Hot water extract of the dried bulb, administered by gastric intubation to mice
at a dose of 0.5 ml (25% of the extract), was active vs alloxan-induced hyperglycemia. When
administered orally to rabbits at a dose of 10.0 ml/animal, a 13.4 mg percent drop in blood
sugar level was observed after 8 days of treatment. Water extract of the dried bulb,
administered intravenously to mice at a dose of 70.0 mg/kg, was active vs alloxan-induced
hyperglycemia (Ross, 2001).
Antihyperlipemic activity. The water extract, administered orally to rabbits at a dose of 10.0
ml/kg, was active. Hyperlipidemia was induced by long term feeding of sucrose. There was a
significant reduction in serum, liver and aorta triglycerides, and serum and liver proteins, and
a significant increase in liver free amino acids. The essential oil, administered by gastric
intubation to rats at a dose of 100.0 mg/kg for 60 days was active. The effect was measured in
the liver vs ethanol-induced hyperlipemia. Results significant at p <0.01 level. The fixed oil,
in the ration of male rats at a dose of 100.0 mg/kg, was active. Simultaneous feeding of
unsaturated oil from the plant material with a high sucrose diet significantly reduced serum
and tissue cholesterol levels, and a small but significant tissue-protein reducing effect was
observed. Water extract of the fresh bulb, in ration of rabbits at a concentration of 20.0% of
the diet, was inactive. The study was conducted for 6 months in cholesterol-loaded animals
(Ross, 2001).
Antihypertensive activity. Ethanol (95%) extract of the fresh bulb, in the ration of rats, was
inactive. The extraction was made at zero degrees Celsius. Four ml of the extract was fed for 3
weeks, then salt was added and the dose increased to 8 ml. salt did not affect blood pressure in
the spontaneously hypertensive animals (Ross, 2001).
Antihypertriglyceridemic effect. Outer sin fiber, in the ration of male rats at a dose of 263.0
gm/day, was active (Ross, 2001).
Anti-implantation effect. Ethanol (95%) extract of the bulb, administered orally to rats, was
inactive. Water extract of the dried seed, administered intraperitoneally to female rats, was
inactive (Ross, 2001).
Anti-inflammatory activity. Ethanol (80%) extract of the bulb, administered by gastric
intubation to male rats at a dose of 100.0 mg/kg, was inactive vs carrageenin-induced pedal
edema (Ross, 2001). The active antiallergic and anti-inflammatory constituents of onion are
the flavonoids (quercetin and kaempferol) (Alcaraz and Jimenez, 1988). The flavonoids act as
anti-inflammatory agents because they inhibit the action of protein kinase, phospholase A2,
cyclooxygenase, and lipoxygenase (Middleton, 1984).
62
Antimatagenic activity. Water extract of the fresh bulb, at a dose of 0.4 ml/plate, was active
on Salmonella typhimurium TA100, vs TRP-P-2 mutagenicity with S9 mix (Ross, 2001).
Antiradiation effect. The dried bulb, in the ration of rats at a concentration of 20.0 mg/kg,
was active vs X-irradiation (Ross, 2001).
Antisickling activity. Water extract of the fresh bulb, in cell culture at a concentration of 40.0
microliters, was active on platelets vs epinephrine-induced aggregation (Ross, 2001).
Antispasmodic activity. Ethanol (95%) extract of the bulb, at a concentration o f4.0 mg/ml,
was active on the guinea pig ileum vs BaCl2, 5-HT, acetylcholine, and histamine spasms
(Ross, 2001).
Antitoxic activity. Essential oil, administered by gastric intubation to rats at a dose of 100.0
mg/kg, was active. The treatment prevented ethanol-induced serum cholesterol and
triglyceride rise, kidney and liver cholesterol accumulation, hepatic total lipid rise, and serum
albumin reduction vs ethanol-induced hyperlipemia (Ross, 2001).
Antitumor activity. Ethanol (95%) extract of the bulb, administered intraperitoneally to rats
at a dose of 50.0 mg/kg, produced weak activity on Sarcoma III (Some other United States
Patents related to onion). Essential oil, applied externally on female mice at a dose of 1.0
mg/animal vs twice weekly 12-0-tetradecanoyl-phorbol-13-acetate promotion fro 2 weeks,
followed by mezerein promotion for 2 weeks, followed by mezerein promotion for 18 weeks,
was active. The dose, when given with a second promoter, produced a 32% decrease in
incidence of papolloma vs DMBA-induced carcinogenesis. Hot water extract of the fresh
bulb, in cell culture, produced weak activity on RAJI cells vs phorbol myristate acetatepromoted expression of EB virus early antigen (Ross, 2001).
Antiviral activity (plant pathogens). Ethanol (80%) extract of freeze-dried entire plant at
variable concentrations in cell culture, was equivocal on Poliovirus 1, and inactive on
Adenovirus (unspecified), Coxsackie B2 virus, Herpes virus type 1, Measles virus and
Semlicki-forest virus vs plaque-inhibition (Ross, 2001).
Antiyeast acitivity. Bulb essential oil, at a concentration of 1.0%/disc, was active on
Brittanomyces anomalus, Hansenula anomala, Kloeckera apiculata and Lodderomyces
elongisporus. A concentration of 10.0%/disc was active on Kluyveromyces fragilis,
Metschnikowia pulcherrima, Pichia membranaefaciens, Rhodotorula rubra, and
Saccharomyces cervisiae, and inactive on Candida lipolytica. Dried oleoresin, on agar plate at
a concentration of 500.0 ppm, was active on Bearyomyces hansenii vs ascospore production,
and on Rhodotorula rubra vs pseudomycelium production. The oleoresin was inactive on
Candida albicans, Saccharomyces cerevisiae, Torulopsis glabrata, and Hansenula anomala
vs pseudomycelium production, and on Hansenula anomala, Sacchromyces cervisiae and
Lodderomyces elongsporus vs ascospore production. Weak activity was produced on
Lodderomyces elongisporus vs ascospore production. A concentration of 500.0 ppm, in broth
culture, was active on Debaryomyces hansenii, Hansenula anomala and Saccharomyces
cervisiae vs biomass production, and inactive on Candida lipolytica, Koeckera apoculata,
Loddermyces elongisporus, Rhodorotula tubra and Torulopsis glabrata vs biomass
production. Ethanol/water (1:1) extract of the bulb, at a concentrations of 500.0 mg/ml and
1042 mg/ml (dry weight of the plant material) on agar plate, were inactive on Candida
63
albicans and Sacchoromyces pastorianus. The fresh bulb, on agar plate, was inactive on
Candida stellatoidea, MIC 1000.0 mcg/ml and Candida albicans, MIC >470.0 mcg/ml. the
chloroform extract was inactive on Candida albicans, MIC >6.0 mg/ml. Tincture of the dried
bulb (10 gm of plant material in 100 ml ethanol), on agar plate at a concentration of 30.0
microliters/disc , was inactive on Candida albicans. Water extract of the bulb, on agar plate,
produced weal activity on Candida albicans and Saccharomyces cerevisiae (Ross, 2001).
Ascorbic acid lowering effect. The fresh bulb, in the ration of rats at a concentration of 3.0%
of the diet, was active (Ross, 2001).
ATPase (mg++) inhibition. The bulb, administered intragastrically to rats, was active, and the
water extract was inactive on RBC (Ross, 2001).
ATPase inhibition. Water extract of the fresh bulb, in the ration of rabbits at a concentration
of 20.0% of the diet, was active. The study was conducted fro 6 months in cholesterol-loaded
animals (Ross, 2001).
Blood pressure effect (biphasic). Water extract of the dried bulb, administered intravenously
to cats and rats at a dose of 0.1mg/kg, was active. A concoction of Nicotiana tabacum leaf,
Ocimum basilicum leaf, Allium sativum leaf, Allium cepa bulb, Allium ascabricum bulb,
Citrus limon fruit juice, cow’s urine, and trona (an alkaloid mineral substance) was used. The
treatment produced an initial hypotensive effect followed by hypertension (Ross, 2001).
Bradycardia acitivity. Water extract of the dried bulb, administered intravenously to cats and
rats at a dose of 10-20 mg/kg, produced weak activity (Ross, 2001).
Bronchodilator activity (autonomic). Chloroform extract of the fresh bulb, administered
intragastrically to guinea pigs at a dose of 20.0 mg/kg, was active vs allergen-induced
bronchial obstruction. A dose of 80.0 mg/kg was active vs PAF-induced bronchial
obstruction. Ether extract, at a dose of 20.0 mg/kg, and lyophilized extract, at a dose of 100.0
mg/kg, were active vs allergen-induced bronchial obstruction (Ross, 2001).
Carcinogenesis inhibition. Essential oil, applied externally to mice at a concentration of 0.01
mg/animal, was active vs phorbol myristate acetate-induced carcinogenesis of the skin. A
dose of 2.0 mg/animal, applied 30 minutes before DMBA, resulted in 50% decrease in
incidence of carcinoma vs DMBA-induced carcinogenesis (Ross, 2001).
Cardiac activity. Ethanol (95%) extract of the bulb, administered by perfusion to the heart of
the guinea pig at a dose of 10mg, was inactive (Ross, 2001).
Cardiovascular effect. Water extract of the dried bulb, administered intravenously to cats
and rats at a dose of 10-20 mg/kg, produced no change in ECG (Ross, 2001).
Choleretic activity. Butanol extract of the bulb, in the ration of dogs, was active. The fresh
bulb juice was active on rats (Ross, 2001).
Cholesterol inhibition. The entire plant, together with cholesterol in the ration of rabbits, was
inactive (Ross, 2001).
64
Cholesterol level decrease. The fresh bulb, in the ration of rats at a concentration of 3.0% of
diet, was active (Ross, 2001).
Chronotropic effect (positive). Ethanol/water (1:1) extract of the fresh bulb, administered by
gastric intubation to rats at a dose of 40.0 ml/kg, was active (Ross, 2001).
CNS depressant activity. Butanol extract of the bulb, in the ration of dogs, was active (Ross,
2001).
Coagulant activity. Essential oil, administered by gastric intubation to male rabbits at a dose
of 2.0 gm/kg for 3 months, produced strong activity. There was an increase in coagulation
time. Results significant at p <0.001 level (Ross, 2001).
Cyclooxygenase inhibition. Essential oil of the dried entire plant, at a concentration of 0.35
mg/ml, was active on rabbit platelets (Ross, 2001).
Cytotoxic
+ activity. The dried bulb, in cell culture at a concentration of 25.0% was active on HamsterCA-HCPC-1. Water extract of the fresh leaf, on agar plate, was inactive on Ustilago nuda
(Ross, 2001).
Desmutagenic acitivity. Aqueous high speed supernatant of the fresh unripe fruit juice, on
agar plate at a concentration of 0.5 ml/plate, was inactive on Salmonella typhimurium TA98
vs mutagenicity of L-tryptophan pyrolysis products. The assay was done in the presence of S9
mix. The fresh plant juice, on agar plate at a concentration of 0.5 ml/plate, was inactive on
Salmonella typhimurium TA98 (Ross, 2001).
Diuretic activity. Butanol extract of the bulb, in the ration of dogs, was active. Ethanol/water
(1:1) extract of the fresh bulb (5 parts of fresh bulb in 100 parts ethanol/water), administered
intragastrically to rats at a dose of 40.0 ml/kg, and was active. The fresh bulb juice
administered by gastric intubation to rabbits, was active. Methanol extract of scales of the
bulb, administered to dogs, was active (Ross, 2001).
DNA synthesis inhibition. Essential oil, applied externally to female mice at a dose of 5.0
mg/animal, produced 86% inhibition when the oil was applied 2 hours before DMBA vs
DMBA-induced carcinogenesis (Ross, 2001).
Embryotoxic activity. Ethanol/water (1:1) extract of the seed, administered orally to female
rats at a dose of 200.0 mg/kg, was inactive (Ross, 2001).
Fibrinolytic activity. The bulb juice, in the ration of rabbits, was active. The essential oil,
administered by gastric intubation to male rabbits at a dose of 2.0 gm/kg for 3 months,
decreased fribrinolytic activity. Results significant at p<0.001 level (Ross, 2001).
Gastric inhibitory polypeptide stimulation. The bulb, in the ration of rabbits and rats,
produced weak activity vs cholesterol-loaded animals (Ross, 2001).
Glucose uptake induction. Ether extract of the fresh bulb, administered intragastrically to
rabbits at a dose of 250 mg/kg, was active vs alloxan-induced hyperglycemia (Ross, 2001).
65
Gluatamate pyruvate transminase inhibition. Water extract of the fresh bulb, in the ration
of rabbits at a concentration of 20.0% of the diet, was active. The study was conducted for 6
months on cholesterol loaded animals (Ross, 2001).
Glutathione peroxidase inhibition. Lyophilized extract of the fresh bulb, in the ration of
chicken at a concentration of 2.0% of the diet, was active (Ross, 2001).
Goitrogenic activity. The bulb, in the ration of rats at a concentration of 20.0% of the diet for
4 weeks, was active (Ross, 2001).
Growth promoter activity. Benzene/chloroform (6:4) extract of the fresh fruit essential oil,
diluted to the same concentration as in fresh onion juice and administered intragasrically to
rats at a dose of 5.0 ml/kg for 42 days, was inactive. Body weight, growth, and organ weights
were unaffected. Protein content of the kidneys was greater than that of controls. Polyamine
content of the organs was not was not different from the the controls. Undiluted essential oil
of the fresh onion, administered intragstrically to rats at a dose of 5.0 ml/kg for 42 days, was
active. Body weight, growth, and weight of the spleen, muscles, heart and protein content of
major organs were greater than vehicle treated controls. Polyamine contents of the liver and
kidney were higher than the controls. Ether extract of fresh onion juice, diluted to same
concentration as fresh onion juice and administered intragastrically to rats at a dose of 5.0
ml/kg for 42 days, was active. Body weight, growth, and weights of muscle, heart, lungs, and
protein content of organs were greater than vehicle-treated controls. Polyamine contents of the
liver and kidneys were higher than the controls. Methanol extract of fresh onion juice, diluted
to the same concentration as fresh onion juice and administered intragastrically to rats at a
dose of 5.0 ml/kg for 42 days, was active. Body weight and the heart and lungs were greater
than the vehicle-treated controls. Polyamine content of the liver was greater than the controls,
but the organ protein content was unaffected (Ross, 2001).
Hemotoxic activity. The bulb, in the ration of guinea pigs at a variable concentrations, was
active the bulb was fed in raw form, cooked or various types of extracts. The result was a
decrease in red blood count; the decrease was proportional to the amount fed. Changes in the
white blood cell count were variable. Death occurred within 23 days after starting the animals
on a diet containing high doses. The red blood cell count decreased from 5 million to 3.5
million. Ethanol (95%) extract of the dried bulb, administered intraperitoneally to guinea pigs,
was active. Anemia was induced. The water and ether extracts were inactive. The fresh bulb,
administered by gastric intubation to dogs at a dose of 15.0 gm/kg, was active. Daily dosing
for 6 days produced anemia characterized by a red blood cell count of 1.99 million (7.76
million prior to onion dosing), and hemoglobin concentration of 30 (91 prior to doing) and a
white blood cell count of 25,000 (10.900 prior to dosing). Data was comparable following
dosing with autoclaved onions and/or autoclaved onion juice. Butanol extract of the fresh
bulb, in the ration of cattle at a concentration of 25.0% of the diet, was active. A decrease in
the number of red blood cells and hemoglobin concentration was observed (Ross, 2001).
Histamine release inhibition. Ethanol (75%) extract of the fixed oil, in cell culture, was
active on the human basophil. The biological activity has been patented (Ross, 2001).
Hydroxy(17)-steroid urinary excretion increased. The fresh bulb, in the ration of rats at a
concentration of 2.0% of the diet, was active (Ross, 2001).
66
Hypercholesterlemic activity. The dried bulb, administered orally to male rats at a dose of
5.0gm/kg daily for 56 days, was active. Water extract of the fresh bulb, administered to rats,
was active (Ross, 2001).
Hyperglycemic activity. The fresh bulb and ether extract of the fresh bulb, administered to
pancreatectomized dogs by gastric intubation, were active. Methanol extract of the dried bulb,
administered intragastrically to rats at a dose of 2.0 gm/kg was inactive (Ross, 2001).
Hyperlipidemic activity. Water extract of the fresh bulb, in the ration of rabbits at a
concentration of 20.0% of the diet, was active. The study was conducted for 6 months on
cholesterol-loaded animals (Ross, 2001).
Hypertensive activity. Ethanol (95%) extract of the bulb, administered inravenously to dogs
at a dose of 100.0 mg/kg, was inactive (Ross, 2001).
Hypocholesterolemic activity. The fresh bulb, administered intragastrically to rats, was
active. Lyophilized extract of the fresh bulb, in the ration of chicken at a concentration of
2.0% of the diet, was inactive (Ross, 2001).
Hypoglycemic activity. Chloroform extract of the raw bulb, administered by gastric
intubation to rabbits, produced strong activity vs glucose-induced hyperglycemia. The
treatment was 79.4% as effective as tolbutamide. The petroleum ether extract was active.
Chloroform, ethanol (95%), and petroleum ether extracts of the fresh bulb, administered by
gastric intubation ot rabbits, were active. Ethanol (95%) extract of the bulb, administered by
gastric intubation to rabbits, was active. The petroleum ether extract produced strong activity.
Ether and petroleum ether extracts of the bulb, administered by gastric intubation to male
rabbits at a dose of 0.25 gm/kg, were active. Ether extract of the fresh bulb, administered to
pancreatectomized dogs and rabbits by gastric intubation, was active. Ether extract of the
fresh bulb, administered intragastrically to rabbits at a dose of 250 gm/kg, was active. A dose
of 10.0 mg/kg, administered orally to rabbits, was active. A drop in blood sugar of 15 mg
relative to inert-treated controls indicated positive results. The fresh bulb juice, administered
intravenously to rabbits, was active. Methanol extract of the dried bulb, administered to rats at
a dose of 2.0 gm/kg, was inactive. Petroleum ether and petroleum ether-insoluble extracts of
the dried bulb, administered by gastric intubation to female rats at a dose of 0.25 gm/kg, were
inactive. The plant juice, administered subcutaneously to rats at a dose of 0.5 ml/animal daily
for 10 days, was inactive. Fasting blood sugar levels were determined (Ross, 2001).
Hypolipemic activity. The essential oil, administered by gastric intuabaion to rats at a dose of
100.0 mg/kg for 60 days, was active. The effect was measured in the liver. Results significant
at p <0.01 level vs ethanol-induced hyperlipemia. The fresh bulb and water extract of the fresh
bulb, administered intragastrically to rats, were active on RBC. The bulb juice, in the ration of
rabbits, was active. The treatment prevented a rise in the levels of serum cholesterol for up to
60 days (Ross, 2001).
Hypotensive activity. Chloroform extract of the fresh bulb, administered intravenously to rats
at a dose of 1.0 mg/animal, was active. Ethanol (70%) extract of the fresh bulb, administered
intravenously to rats at variable dosage levels, was active. Ethanol (95%) extract of the bulb,
administered intravenously to dogs at a dose of 100.0 mg/kg, was inactive. Ethanol/water
67
(1:1) extract of the fresh bulb sap, administered by gastric intubation to rats at a dose of 40.0
ml/kg, produced weak activity. Water extract of the dried bulb, administered intravenously to
cats and rats at doses of 5 to 20 mg/kg, produced weak activity (Ross, 2001).
Hypotriglyceridemia activity. Lyophilized extract of the fresh bulb, in the ration of chicken
at a concentration of 2.0% of the diet, was inactive (Ross, 2001).
Immunosuppressant activity. Aqueous suspension of the fresh bulb, administered by gastric
intubation to rabbits at a concentration of 10.0%, was active (Ross, 2001).
Insect attractant activity. Butanol extract of the fresh bulb was active on Delia antique
(Ross, 2001).
Lactate dehydrogenase stimulation. Water extract of the fresh bulb, in the ration of rabbits
at a concentration of 20.0% of the diet, was active. The study was conducted for 6 months in
cholesterol-loaded animals (Ross, 2001).
Lipid metabolism effects. Ethanol (100%) extract of the bulb was active in rats. Ethanol
(95%) extract of the fresh bulb, in the ration of rats, was active. The extraction was made at
zero degrees Celcius. 4 ml of the extract was fed for 3 weeks , then salt was added and the
dose increased to 8 ml. Salt did not affect blood pressure in the spontaneously hypertensive
animals. Arachidonic acid level was decreased (Ross, 2001).
Lipid peroxide formation inhibition. Hot water extract of the fresh bulb was active vs Tbutyl hydroperoxide/heme-induced luminol-enhanced chemiluminescence (Ross, 2001).
Lipoxygenase inhibition. Ethanol (75%) extract of the fixed oil was active on the
polymorphonuclear leukocytes of guinea pigs. The biological activity has been patented.
Methanol extract of the fresh bulb, at a concentration of 100.0 mcg/ml, was active on the rat
platelets. Ether-soluble material produced 77% inhibition and the ether-insoluble material was
inactive with zero percent inhibition (Ross, 2001).
Lipoxygenase stimulation. Essential oil of the dried entire plant, at a concentration of 0.35
mg/ml, was active on the rabbit platelets (Ross, 2001).
Mutagenic activity. The bulb was active on Salmonella typhimurium TA98.
Cholesterol/methanol (2:1) extract of the bulb, on agar plate at a concentration of 100.0
mg/plate, was inactive on Salmonella typhimurium TA100 and TA98. The water extract was
inactive on pig kidney cells LLC-PK—1 and trophoblastic-placenta cells. The effect was the
same with or without embolic activation. Ethanol (95%) extract of the dried bulb, on agar
plate at a concentration of 10.0 mg/plate, was inactive on Salmonella typhimurium TA102 and
TA98. The fresh bulb, on agar plate at a concentration of 1.2 mg/plate, was active on
Salmonella typhimurium TA1535, and inactive on TA98. A concentration of 2.4 mg/plate was
active on TA1537 and TA1538. Water extract of the fresh bulb, on agar plate, was inactive on
Salmonella typhimurium TA100 (Ross, 2001).
Nucleotidase inhibition. Water extract of the fresh bulb, administered intragastrically to rats,
was active on RBC (Ross, 2001).
68
Phorbol ester antagonist. The essential oil, applied externally to female mice at a dose of 5.0
mg/animal, was active. The dose was applied 1 hour before application of 12-0-tetradecanoylphorbol-13-acetate. 16 hours later, the rate of DNA synthesis was decreased by 79%. The
fresh bulb was active vs phorbol myristate acetate-induced decrease in glutathione peroxidase,
and stimulation of ornithine decarboxylase (Ross, 2001).
Plant germination inhibition. Water extracts of the dried leaf and dried stem, at a
concentration of 500.0 gm/liter, were active on the seeds of Cuscuta reflexa after 6 days of
exposure to the extract (Ross, 2001).
Plant growth inhibition. Water extract of the dried stem, at a concentration of 500.0 gm/liter,
was active on Cuscuta reflexa. Seedling length, weight, and dry weight were measured after 6
days of exposure to the extract (Ross, 2001).
Plant pollen tube elongation inhibition. The fresh bulb, at a concentration of 0.3 gm/well,
was active vs Camellia sinesis pollen. Water extract of the bulb, at a concentration of 0.001%,
was active on Calotropis gigantea (Ross, 2001).
Plasminogen activation stimulation. Water extract of the bulb was active (Ross, 2001).
Platelet adhesion inhibition. The essential oil, administered by gastric intubation to male
rabbits at a dose of 2.0 gm/kg for 3 months, was active. Results significant at p <0.001 level
(Ross, 2001).
Platelet aggregation inhibition. Butanol extract of the bulb, at a dose of 20.0 microliters,
was active on human platelets vs ADP-induced aggregation. Ethanol-insoluble fraction, at a
concentration of 20.0 microliters, was active vs ADP-induced aggregation. One out of 6
fractions extracted showed activity. Butanol extract of the fresh, taken orally by adults at a
dose of 200.0 gm/person, was active. The subjects consumed a high fat meal prior to testing.
Chloroform extract of the bulb, at variable dosage levels, was active on platelets of human and
rabbits. Platelet aggregation was inhibited by the blocking of thromboxane synthesis. The
essential oil, at concentrations of 10 to30 mcg/ml, produced strong activity in human adults vs
ADP-induced aggregation. There was induction of a redistribution of the products of
lipoxygenase pathway. Concentrations of 30 to 60 mcg/ml also produced strong activity vs
ADP-induced aggregation. There was complete suppression of the formation of all oxygenase
products. The essential oil produced weak activity on human platelets vs ADP-induced
platelet aggregation. Water extract of the fresh bulb, in cell culture at a dose of 10.0
microliters, was active vs ADP-induced aggregation. A dose of 30.0 microliters was active vs
collagen-, epinephrine- and arachidonic acid-induced aggregation. Water extract of the fresh
bulb was active vs ADP-and arachidonic acid-induced platelet aggregation (Ross, 2001).
Pro-oxidant activity. The fresh bulb, at a concentration of 1.0%, was active. The effect was
observed at 140 degrees Fahrenheit in peanut oil (Ross, 2001).
Prostaglandin inhibition. Water extract of the fresh bulb, in cell culture, was active on
platelets and on the rat aorta (Ross, 2001).
Protein synthesis inhibition. The fresh bract, in buffer, was active, IC50 60.0 mcg protein/ml
(Ross, 2001).
69
Quinone reductase induction. Aceonitrile extract of the dried bulb, in cell culture at a
concentration of 7.9 mg/gm, was active on mice hepatoma-ICIC7. Assay was conducted to
determine the induction of detoxifying enzyme, an effect that may have anticarcinogenic
activity (Ross, 2001).
Respiratory depressant. Ethanol (95%) extract of the bulb, administered intravenously to
dogs at a dose of 100.0 mg/kg, was inactive (Ross, 2001).
Respiratory stimulant effect. Ethanol (95%) extract of the bulb, administered intravenously
to dogs at a dose of 100.0 mg/kg, was inactive (Ross, 2001).
Smooth muscle relaxant activity. Ethanol (95%) extract of the bulb, administered by
perfusion to guinea pig lung at a dose of 5.0 mg, was active (Ross, 2001).
Smooth muscle stimulant activity. Chromatographic fraction of the fresh bulb was active on
the stomach (fundus). The fresh bulb juice was active on the rat intestine (Ross, 2001). Oral
administration of an ethanol extrct of the drug to guinea-pigs inhibited smooth muscle
contraction in the trachea induced by carbachol nd inhibited histamine-, barium chloride-,
serotonin-, and acetycholine-induced contractions in ileum (Dorsch et al., 1991).
Spermicidal effect. The essential oil was active in guinea pigs (Ross, 2001).
Superoxide inhibition. Lyophilized extract of the fresh bulb, in the ration of chicken at a
concentration of 2.0% of the diet, was active. Mn-superoxide dismutase activity was
stimulated (Ross, 2001).
Sympathomimetic activity. Water extract of the dried bulb, administered intravenously to
cats at a dose of 0.05 mg/ml, was active. A concoction of Nicotiana tabacum leaf, Ocimum
basilicum leaf, Allium sativum leaf, Allium cepa bulb, Allium ascabricum bulb, Citrus limon
fruit juice, cow’s urine, and trona (an alkaloid mineral substance) was used. The treatment
enhanced the contractile response of the cat ictating membrane evoked by preganglionic
cervical sympathetic nerve stimulation. At a higher dose, it caused contraction without nerve
stimulation (Ross, 2001).
Thromboxane B-2 synthesis inhibition. Essential oil of the dried entire plant was active on
rabbit platelets, IC50 0.125 mg/ml. Ether extract of the fresh bulb juice, in cell culture, was
active on fibroblasts-human-lung and platelets. Water extract of the fresh bulb, in cell culture,
was active (Ross, 2001).
Tumor necrosing factor induction. The fresh bulb juice, administered intravenously to mice
at a dose of 200.0 microliters/animal, was active. Three hours after priming TNF production
with the juice, intravenous injection of OK-432 or IFN-Gamma was used to trigger TNF
production. Two hours later, TNF was assayed by its cytotoxicity against L929 cells (Ross,
2001).
Tumor promoting effect. Hot water extract of the fresh bulb, applied externally to mice at a
dose of 10.0 mg/animal, was active. The dose was applied 3 times weekly fro 49 to 60 weeks
after tumor initiation vs DMBA-induced carcinogenesis (Ross, 2001).
70
Tumor promotion inhibition. Ethyl acetate extract of the fresh root, in cell culture at a dose
of 200.0 mcg, was active on Epstein-Barr virus vs 12-0-Hexadecanoylphorbol-13-acetateinduced Epstein-Barr activation. The methanol extract was inactive (Ross, 2001).
Uricosuric activity. Benzene/chloroform (6:4) and ether extracts of the fresh onion juice and
the essential oil, diluted to the same concentration as in fresh onion juice and administered
intragastrically to rats at a dose of 5.0 ml/kg for 42 days, were inactive. Urinary urea content
was increased transiently, then decreased below the level of the vehicle-treated controls.
Allantoin level in the urine was greater than that in the control group. The methanol extract of
fresh onion juice, diluted to the same concentration as in fresh onion juice and administered
intragastrically to rats at a dose of 5.0 ml/kg for 42 days, was inactive (Ross, 2001).
Uterine stimulant effect. Fresh bulb juice was active on the uterus of rats. The treatment was
equivalent to 0.003 IU of oxytocin. Water extract of the bulb was active on non-pregnant, and
produced strong activity on pregnant mice and rats (Ross, 2001).
WBC macrophase stimulant. Water extract of the freeze-dried bulb, at a concentration of
2.0 mg/ml, was inactive on sarcoma (Yoshida ASC). Nitrite formation was used as an index
of the macrophase stimulating activity to screen effective foods (Ross, 2001).
WBC stimulant. Fresh bulb juice, administered intraperitoneally to mice, was active.
Neutrophil accumulation was increased 78%, ED50 0.15 ml/animal (Ross, 2001).
Clinical and Toxic effect
Clinical effects
Oral administration of a butanol extract of bulbus Allii Cepae (200mg) to subjects given a
high-fat meal prior to testing suppressed platelet aggregation associated with a high-fat diet
(Anonymous, 1999).
A saponin fraction (50mg) or the bulb (100mg) also decreased serum cholesterol and
plasma fibrinogen levels. However, fresh onion extract (50g) did not produce any significant
effects on serum cholesterol, fibrinogen, or fibrinolytic activity in normal subjects (Sharma
and Sharma, 1976: Sharma and Sharma, 1979). Administration of a butanol extract to patients
with alimentary lipaemia prevented an increase in the total serum cholesterol, β-lipoprotein
cholesterol, and β-lipoprotein and serum triglycerides (Anonymous, 1999). The bulb, taken
orally by human adults at a dose of 100.0 gm/person, was active. Statistical data indicate
significant results. Butanol extract of the fresh bulb, taken orally by male human adults at a
dose of 500.0 gm/person, was inactive. The study utilized 10 healthy subjects ranging in age
from 18 to 30 years. The subjects were given a fatty breakfast containing 100 gm butterfat.
The breakfast produced a significant increase in serum cholesterol and plasma fibrinogen, and
a decrease in blood fibrinolytic A. After the administration of either raw or boiled onion, no
significant change in serum cholesterol or plasma fibrinogen levels was seen. Statistical data
indicate significant results (Ross, 2001).
The bulb, taken orally by human adults at a dose of 100.0 gm/person, was active. The
essential oil, taken by male adults, was antihyperlipemic (Ross, 2001).
Antihyperglycaemic activity of Bulbus Allii Cepae has been demonstrated in clinical
studies. Administration of an aqueous extract (100mg) decreased glucose-induced
hyperglycaemia in human adults. The juice of the drug (50mg) administered orally to diabetic
patients reduced blood glucose levels. Addition of raw onion to the diet of non-insulin-
71
dependent diabetic subjects decreased the dose of antidiabetic medication required to control
the disease. However, an aqueous extract of Bulbus Allii cepae (200mg) was not active
(Anonymous, 1999). The water extract, taken orally by adults at a dose of 200.0 gm/person,
was inactive as hypoglycemic agent (Ross, 2001).
The immediate and late cutaneous reactions induced by injection of rabbit anti-human
IgE-antibodies into the volar side of the forearms of 12 healthy volunteers were reduced after
pretreatment of the skin with a 50% ethanol onion extract. Immediate and late bronchial
obstruction owing to allergen inhalation was markedly reduced after oral administration of a
5% ethanol onion extract 1 hour before exposure to the allergen (Anonymous, 1999).
In one clinical trial in 12 adult subjects, topical application of a 45% ethanolic onion
extract inhibited the allergic reactions induced by anti-IgE (Anonymous, 1999). The bulb,
taken orally by human adults at variable dosage levels, was active. The study involved 100
patients with bronchial asthma. Chloroform and ethanol (95%) extracts of the dried bulb were
active in adults (Amla et al., 1981).
Juices of the bulb of red globe, white globe, and madras varieties were active
lacrymation stimulant when applied ophthalmically to human adults (Ross, 2001).
The bulb, taken orally by adults, was appetite stimulant. It is claimed to be ba tonic
medicine and capable of accelerating recovery from fatigue. When mixed with equal weight
of starch, it is free of unpleasant odor and taste. The biological activity has been patented
(Ross, 2001).
Toxic effects
Animal data
A review of literature discussing large amounts of onion bulb ingestion leaves toxicity
questions unresolved (Kendler, 1987). Butanol extract of the fresh bulb, in the ration of dogs
at undiluted concentration, was active. A pug puppy was referred to a Veterinary college. The
dog had a depraved appetite and preferred raw onion to other vegetables, which led to anemia
in the dog (Ross, 2001). Low doses of onion (50 mg/kg) given to rats had little effect on the
lung and liver tissues. High doses (500 mg/kg) resulted in histological changes in these
organs. Intraperitoneal administration was more damaging than oral administration, resulting
in 25% mortality in rats (Thomson et al., 1998). Eighty-five young cattle were allowed 1,000
kg/day of onion, negatively affecting approximately 26%, with 1 fatality. New illnesses
continued to occur for 5 days after the withdrawal of onion, including lack of appetite,
tachycardia, staggering, and collapse, all probably because of adverse red blood cell effects
(Verhoeff et al., 1985).
Clinical data
Certain sulfur compounds (eg, propanethial-S-oxide) escape from onion in vapor form and
hydrolyze to sulfuric acid when cut, causing the familiar eye irritation and lacrimation.
Corneal swelling from onion exposure has been reported (Chan and Mandell, 1972). With
large intake, the stomach may be affected, and frequent contact with onion rarely causes
allergic reaction (URL-21). Onion seeds have been reported as occupational allergens
(Navarro et al., 1995). Onion toxicity is only associated with high intake (URL-21). Most
people can eat onion in food without any difficulties. Higher intakes of onion may worsen
existing heartburn, though it does not seem to cause heartburn in people who do not already
have it (Allen et al., 1990). There are also isolated reports of allergy to onion manifesting as
skin rash and red, itchy eyes. Onion is safe for use in children and, in small amounts in food,
during pregnancy (though some pregnant women may have heartburn that onions could
exacerbate) and nursing (URL-22). Dosages above those found in foods should be avoided
72
because safety and efficacy are unproven (URL-21). A large hepatitis A outbreak was
identified due to consumption of green onion in a restaurant. But a case-control study
concluded it was due to green onions that were apparently contaminated before arrival at the
restaurant (Wheeler et al., 2005).
12. Formulation
They are used therapeutically in the Ayurvedic (Kapoor, 1990), Siddha and Unani systems of
Indian medicine, in various dosage forms including the decoction, infusion, and fresh juice, as
well as raw, cooked, and/or roasted bulb. The juice form is usually combined with honey,
ginger rhizome juice, and ghee (liquid clarified butter) (Nadkarni, 1976).
Dosage and administration
Unless otherwise prescribed, a daily dose is 50 g of fresh bulb or 20 g per day of dried bulb
(Anonymous, 1999).
Dried bulb: 20 g
Fresh bulb: 50 g
Infusion: Steep 1–2 teaspoons in 120 ml water
Succus: 5 ml (1 teaspoon) pressed juice of fresh bulb, three to four times daily
Tincture: 5 ml (1 teaspoon), three to four times daily
Duration of administration: Note: If onion preparations are used over several months, the
daily maximum amount for diphenylamine is 0.035 g (URL-23).
Some formulation from Hamdard Pharmacopoea of Eastern Medicine
1. ARQ ANANAS (contains Allium cepa bulb)
Recipe:
Tribulus terrestris, semi-ground (majith nim kofta)-300 grams
Allium cepa bulbs (piyaz safaid) - 300 grams
Pineapple preserve (ananas kalan) - 20 Nos
Water (pani) - 12 litres
Preparation:
The first two ingredients are soaked in 12 litres of overnight. The next morning the Allium
cepa bulbs and the pineapples are sliced and depeeled, after which they are added to the
infusion. About 7.5 litres of the aqua are obtained by distillation and stocked in bottles.
Dosage and administration:
15ml with shalbat bazuri motadil (25 ml). q.v.
Uses and indications:
i.
Lithontriptic for the kidney and gall bladder.
ii.
Diuretic.
iii.
Antiphlogistic and refrigerant for the kidney and gall bladder.
2. JAWARISH ZAR’UNI AMBARI BA NUSKHA KALAN
3. ARQ HAZIM
4. LUBUB-AL-ASRAR
5. LUBUB KABIR
6. MA’JUN PIYAZ
7. MA’JUN RAIG MAHI
73
8. MA’JUN MURRAWEH-UH-ARWAH
9. MA’JUN MUQAWWI WA MUMSIK
(Said, 1997)
13. Commercial value
13.1. Production
As of the late 1970s, the Food and Agirculture Oraganization (FAO) of the United Nations
reports total worldwide annual production of dry onions at 16 million metric tons (18 million
tons). In terms of the continents, Asia led with 46.2% of the total production, followed by
Europe (28.7%); North and Central America (10%); Africa (7.8%); South America (6.5%);
and Oceania (0.8%).
In terms of countries, China led in production with 14% of the total, followed by India
(9.6%); the United States (9.4%); Japan (6.2%); Spain (5.4%); Egypt and the U.S.S.R., each
with 4.4%; Turkey (4.2%); Italy (3%); the Netherlands (2.5%); Poland (2.2%); Brazil,
Indonesia and Iran, each with 2%; Yogoslavia (1.9%); Argentina (1.8%); Rumania (1.7%);
and the United Kingdom (1.5%). Together, these countries account for 77.8% of total world
production (Considine and Considine, 1997).
Of the vegetables crops listed by FAO, the onion falls second only to tomatoes in
terms of tones per annum world production. Average yields of bulb onions range from around
30 tonne/ha in North West Europe to less than 8 tonne/ha as an average for developing
countries.
FAO statistics show that in 2000 global green onion and shallots production and
productivity was from 227137 ha planted- with a total production of 4109099 Mt giving an
average yield of 18091 kg/ha.
The data for dry onions was 2705030 ha giving 47781146 Mt; an average global yield
of 17664 kg/ha (URL-5).
13.2. Markets
Ripe onions are either marketed soon after harvesting or kept in storage for disposal at a later
stage. When the produce is to be disposed of at harvest, it is taken to the market in ordinary
gunny bags, but it is advisable to use open mesh sacs with a coarse mesh through which the
bulbs can be seen easily. These are attractive and give ventilation and facilitate inspection by
the prospective buyer. It is desirable that proper grading is done before the produce.
Onions are found to be marketed in many forms- the fresh markets include naturally
dried onions and several types of green onions- salad leaves and roasting and salad bulbs.
World War II stimulated the technology for commercial drying techniques. Reduction in bulk,
by dehydration or flavour extraction results in decreased transportation and storage costs and
lower seasonal fluctuations in cost, quality and availability. However, this may result in
undesirable appearance changes and modification of the natural balanced aroma and flavour.
Processed products available for market are: dehydrated or lyophylised products, onion oil,
juice, solid flavourings, pickled onions and canned and bottled onions (URL-5).
13.3. Trade and economic impact
The onion bulb produced in the hills have a very high potential to supply to the domestic
markets of the Terai, and onion seeds have window of opportunity to supply to the south east
Asian
countries
(Gautam
et
al.,
1997).
74
Food
quantity
(1000
tonnes)
Producer
price (US
$/ tonne)
Quantity
produced
(1000
tonnes)
Yield per
hectar
(tonnes/Ha)
Area
harvested
(1000 Ha)
Feed
&
Seed
quantity
(1000
tonnes)
Other net
uses
quantity
(1000
tonnes)
Export
quantity
1990
9.30
Table 3: FAO Data on Onion
1991 1992 1993 1994 1995 1996 1997 1998 1999
2000 2001 2002
0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2.77
0.05 0.01 8.45
2003 2004
37.75 31.49
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
9.18
9.39
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.10
0.10
0.00
0.00
0.00
-1.09
0.02
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.37
0.05
0.00
0.00
0.00
0.31
75
(1000
tonnes)
Import
quantity
(1000
tonnes)
Import
value
(Million
US $)
Avg.
Import unit
value (US
$/ tonne)
Net trade
(X-M)
(1000
tonnes)
9.32
-
-
-
-
-
-
-
-
-
-
-
-
-
-
0.78
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.58
0.00
0.00
0.88
3.26
2.80
83.69 -
-
-
-
-
-
-
-
179.01 -
0.00
104.14 86.89 91.18
-9.30
0.00
0.00
0.00
0.00
0.00
0.00
0.00
-2.87
0.01
-8.45
0.00
0.05
Source: FAO Statistics Division, 2006(URL-24)
76
37.75 30.40
14. Perspective
14.1. Status
Only some species of the section Allium is found to be in the list of endangered species. Taxa
of more local distribution are seriously endangered. Therefore, in the Soviet Union, three
species of the section are listed in the new edition of the Red Book of the U.S.S.R. (a list of
endangered species in U.S.S.R.), as either nearly extinct (e.g., Allium microbulbum), or
threatened by the rapidly decreasing number of localities at which they occur (Allium vavilovii
and Allium pskemense). Also the Red Books of the individual Republics of the U.S.S.R.,
include some species of the section (e.g., in Uzbekistan Allium oschaninii, A. pskemense, and
Allium praemixturn) (URL-25).
14.2. Patent
Some biological activities of onion have been patented like apetite stimulant,
histamine release inhibition and lipoxygenase inhibition (Ross, 2001).
United States
Patent No.
7007449
6759068
6468565
6443234
6406734
6403642
6007809
5514366
5405640
5391390
5367111
5260090
4889046
4622906
4602455
4579028
4545297
4476778
4470345
4442764
4430352
Table 4: Some other United States Patents related to onion
Patent Title
Onion harvester with leaf topper
Onion and garlic biohydrolysates and their use as natural flavorings
Onion extract rich in sulfurized cyclic amino acid and process for producing
the same
Bulbous onion harvester and trimmer
Method for imparting a fried onion aroma to foodstuffs
Sulfur adsorbent for reducing onion or garlic breath odor
Method and product for eliminating undesirable side effects of eating
vegetables such as onion or garlic
Dental and oral preparation for smokers for solubilizing and removing
tobacco tars as well as onion and garlic essential oils
Process of vacuum treating onions
Treatment of bulb vegetables such as garlic, onions and the like to free them
from the so-called day-after effect
Hybrid plants of onion and garlic or Chinese chive and method for breeding
and propagating the same
Process for deodoring garlic or welsh onion and the like
Device for peeling onions or other bulbous or tuberous plants
Onion planter
Method and apparatus for cultivating young seedlings of Welsh onion
Onion dicer
Onion peeling device
Onion peeling
Apparatus for peeling skins off the bulbs of onions
Machine for peeling and cleaning foodstuffs, particularly vegetables such as
onions
Preparation of fresh chopped onions which may be dispensed from tubes
77
4394394
Process for producing dry discrete agglomerated garlic and onion and
resulting products
Harvesting apparatus for onions
Process for controlling the pinking of onions
Process of producing a batter-coated onion product
Onion capsule harvester and process
Method and apparatus for trimming onions or like produce
Method of peeling onions by scalding and cutting
Method of sweetening or mellowing onions
4373589
4374153
4351850
4257216
4202261
4068011
4034118
(URL-26)
The antiviral composition derived from onion is also patented under the title “Antiviral
composition derived from allium CEPA and therapeutic use thereof” (United States Patent
6340483) (URL-27).
14.3. Diagnostic characters
Fibrous root, parallel veined leaves, trimerous flower, six tepals in two whorls, superior,
trilocular, six stamens in two whorls, antipetalous, epiphyllous, gynoecium- tricarpellary,
trilocular and axile placentation (Ranjitkar, 1995).
14.4. Occurrence
Among the edible Allium the onion (Allium cepa L.) stands in the first rank, in the warmtemperate hills of eastern Nepal, followed by garlic (Allium sativum) and shallot (Allium cepa
Aggregatum group) (Gautam et al., 1997).
14.5. Taste and Potency
Onion has a prominent place in human diet. It is popularly used in green and mature
vegetable salads, pickles, sauces, etc. It introduces a rich, healthy and tasteful variation in
common diet (Anonymous, 2003). Onion has strong pungent taste (Anonymous, 1999;
Anonymous, 2003). Onion oil has acrid taste and unpleasant odour (Anonymous, 2003).
Among the two main varieties of onions found in cultivation, viz. (1) the big sized
onions with single bulbs and white or pink flesh, and (2) the small-sized onions with multiple
bulbs having a white or red skin, the latter type are smaller but the flavour of the bulbs is
stronger. So they are more popular than the single bulb type (Anonymous, 2003).
14.6. Substitutes and Adulterants
Addition of aliphatic sulphide mixtures has been found to the onion oil (Burfield, 2003).
78
15. Miscellaneous
15.1. Herbarium collection
Herbarium number: 1272
79
16. References
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URL-1 (http://www.halcyon.com/tmend/onion5.gif)
URL-2 (http://ecoport.org/ep?Plant=364&entityType=PL****&entityDisplayCategory=full)
URL-3
(http://ecoport.org/ep?status=IN&status=RE&entityId=364&mapCode=xw&searchType=entit
yDistributionMap)
URL-4 (http://herbalextractsplus.com/onion.cfm)
URL-5 (http://ecoport.org/ep?Plant=364&entityType=PLCR**&entityDisplayCategory=full)
URL-6
(http://www.arts.ualberta.ca/axismundi/2002/An_Analysis_Of_Eating.pdf#search=%22hindui
sm%20and%20onion%22)
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URL-8 (http://www.wscandles.com/herbal_magic.php)
URL-9 (http://www.hindu.com/op/2006/01/01/stories/2006010103611600.htm)
URL-10 (http://www.myswizard.com/2005/12/18/hinduism)
URL-11 (http://oregonstate.edu/dept/hort/233/onion.htm)
URL-12 (http://plants.usda.gov/java/profile?symbol=ALCE)
URL-13 (http://www.promotega.org/csu30004/images/onionparts)
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83
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ic=&isd=&isdto=&ttl=onion&abst=&aclm=&spec=&an=&acn=&as=&ac=&ccl=&icl=&apn
=&apd=&apdto=&parn=&refe=&fref=&oref=&prir=&pex=&asex=&agt=&uspat=on&date_r
ange=all&stemming=on&sort=chron)
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84
Glossary of Botanical terms
Adaxial. The surface, usally of a leaf, facing the stem. Next to the axis.
Adventitious. Of organs or tissues developing from stems.
Alternate. Of leaves or branches that are arranged singly on the parent axis.
Androecium. A collective term for the stamens of a flower.
Anther. The part of the flower of Angiosperm producing pollen (microspores), borne at the
end of stamens, and usually consisting of four sporangia.
Antipetalous. Opposite the petals.
Apical meristem. The group of acitivity dividing cells found at or near the tip of a stem, root
or sometimes, a leaf. It originates from a single cell in the Pteridophytes, and from a group of
cells in Spermatophyta. It brings about an increase in length by forming the primary plantbody.
Apical meristem. The group of actively dividing cells found at, or near the tip of a stem, root
or sometimes, a leaf. It originates from a single cell in the Pteridophytes, and from a group of
cells in Spermatophyta. It brings about an increase in length by forming the primary plantbody.
Axile pacentation. Said of an ovary the ovules attached to the tissues the control axis.
Basifixed. Said of an anther which is attached by its base to the filament.
Blade. The flattened part of the thallus of the larger sea-weeds.
Bract. A small atypical leaf subtending a flower-bud in its axil.
Bracteate. Having bracts.
Bulb. An organ of storage and vegetative reproduction. It consists of a flattened stem bearing
fleshy leaves, or leaf-bases with buds in their axis, and scale leaves.
Capsule. A drug indehiscent fruit consisting of more than carpel.
Chromosome arm. One of the two parts of a chromosome to which the spindle fibre is
attached along the side.
Collateral bundle. A vascular bundle with a strand of xylem, with a strand of phloem
external to it on the same radius.
Columella. The central part of a root-cap which contains statoliths.
Complete flower. A flower having calyx, corolla, stamens and carpels.
Cortex. The tissue in a stem or root between the vascular bundles and the epidermis.
Typically it is parenchyma.
Cross. The act of fertilization between two individuals of different breeds or races.
Cyme. An inflorescense in which the terminal bud is a flower-bud, i.e. it is a sympodium, and
any subsequent flowers are formed in a similar way at the ends of lateral braches.
Epidermis. The outer single layer of cells on an organ. The outer wall may be thickened may
be thickened by the production of a cuticle, and the cells may be extended into hairs.
Epiphyllous. Growing on a leaf.
Exserted. Protruding.
Fibrous root system. A mass of fine adventitious roots, of more-or-less equal thickness, and
bearing finer lateral roots. They are borne on stems or the hypocotyls, e.g. grasses.
Filament. The stalk of a stamen.
Fleshy. Thick and soft, but not necessarily juicy.
Flower. The reproductive stem of the angiosperms. Typically it is made up of a calyx of
sepals, a corolla of petals, (these two being the perianth), an andrecium of stamens, and a
gynecium of carpels. Any of these parts may be missing in a particular flower. The floral axis
is the receptacle.
Foliage leaf. An ordinary green leaf.
85
Herb. A plant having no persistent parts above the ground.
Herbaceous. Soft and green, containing little woody tissue.
Hypodermis. A layer of one, or more cells thick, of thickened cells lying immediately below
the epidermis.
Hypogynous. Said of a flower in which the other parts arise below the gynecium.
Inferior. Said of an ovary where the receptacle encloses it, so that the other floral parts arise
above the ovary. The flower is then epigynous.
Inflorescence. A flowering shoot, bearing more than one flower.
Internode. The stem between two successive nodes.
Isodiametrical. Of the same length, vertically and horizontally.
Lacuna. A large multicellular cavity.
Mesophyll. The parenchyma of a leaf, differentiated into the cyhe longy palisade cells with
large number of chloroplasts and arranged with lindrica axis at right-angles to the epidermis;
and the spongy mesophyll of looselt packed cells with fewer chloroplasts, and large air-space.
Monochasium. A cyme in which each flowering branch bears one other flowering bud in its
turn.
Oblong. Elliptical, blunt at each end, having nearly parallel sides and two to four times as
long as broad.
Obstuse. Rounded or blunt; or being greater than a right-angle.
Ovary. The hollow basal region of a carpel, containing one or more ovules. In a flower with 2
or more united carpels, they form a single compound ovary.
Ovate. Flat and thin, shaped like the longitudinal section of an egg, widest below the middle.
Ovule. The nucellus containing the embryo sac and enclosed by 1 or 2 integuments, which
after fertilization, and subsequent development, becomes a seed.
Palisade cells. A single cell of a palisade layer.
Palisade layer. A layer of elongated cells set at right-angles to the surface of a leaf or thallus,
and underlying the upper epidermis, or layers of cells. Its cell contain numerous chloroplasts
and is concerned with photosynthesis.
Parenchyma. A tissue of differentiated cells, which are more or less spherical, frequently
unspecified, and with cellulose cell-walls. Air-spaces are often present, and the tissue is often
for storage.
Pedicellate. Said of a flower or a fruit having a stalk.
Pedicels. 1. The stalk of an individual flower of an inflorescence. 2. A small stalk.
Perennial. A plant living for three or more seasons and normally flowering and fruiting at
least in the second and subsequent seasons.
Perfect. Said of a flower which has both functional anthers and ovules.
Perianth. The flower envelope, it includes the calyx and corolla, or any one of them.
Periclinal. Said of cell-walls running parallel to the surface of the plant.
Pericyle. A cylinder of vascular tissue, 3-6 cells thick, lying immediately inside the
parenchyma, and sometimes fibres.
Persistant perianth. A perianth which remains unwithered, and often enlarged around the
fruit.
Petaloid. Looking like a petal.
Petals. One of the parts forming the corolla of a flower, usually brightly coloured and
conspicuous.
Pistil. Each separate carpel of an apocarpous or syncarpous 2. The gynecium as a whole,
whether it is apocarpous or syncarpous.
Placenta. 1. The part of an ovary to which the seeds are attached.
Polyandrous. Having a large and indefinite number of stamens.
86
Primordium. The earliest recognizable rudiment of an organ or structure in development.
Protodermal. The external layer of a stem or root apex, one cell thick, and giving rise to the
epidermis.
Rhexigenous. Said of a space formed by the disintegration of cells, especially of secretory
cells leaving a cavity containing the secretion.
Rosette. A group of leaves arising from a short stem, and so lying close together on or near
the ground.
Scale. A thin flat plant member, which may be green when very young, and is usually nongreen at ground-level.
Scape. A flower-stalk which is leafless or nearly so, arising from the middle of a rosette of
leaves. It bears a flower, several flowers or a crowded inflorescence.
Schizogenous. Formed by cracking or splitting.
Seedlings. The young plant developed from a germinating seed.
Sessile. Lack of stalk.
Sheath. A leaf base, it forms a tubular casing around the stem.
Shoot. The part of a plant which develops from the plumule
Spathe. A large bract often coloured or membraneous, enclosing a spadix.
Stamen.The microsporophyll of a flower; made up of the anther and filament.
Stamens. The microsporophyll of a flower; made up of the anther and filament.
Stele. The vascular cylinder. The cylinder or core of vascular tissue in the centre of stems and
roots. It consists of xylem, phloem, and pericyle, in some cases pith and medullary rays. It is
surrounded by an endodermis. The detailed structure differs in different groups of plants.
Stellate. Star like.
Stigma. The receptive part of the stigma.
Stripe. Streak
Striped. Having longitudinal stripes of colour.
Style. The narrow part of the gynecium bearing the stigma.
Superior. Hypogynous.
Syncarpous. Composed of united carpels.
Tepal. A perianth segment, not differentiated into a calyx and corolla.
Tricarpellary. Consisting of 3 carpels.
Trimerous. Arranged in threes or multiples of 3.
Tunicated. Having coat or covering.
Umbel. A raceme in which the axis has not elongated, so that the flowers stalks arise at the
same point. Thus the flowers are in a head, with the oldest at the outside.
Vascular bundle. The longitudinal strand of conducting tissue, consisting essentially of
xylem and phloem.
Vessel. A non-living element of the xylem consisting of a tube-like series of cells arranged
end-to-end, running parallel to the long axis of the organ in which it lies, and in
communication with adjacent elements by means of numerous pits in the side walls. It
functions in the conduction of water and mineral salts, and acts in mechanical support.
87
Glossary of Medical Terms
Abortifacient. 1. Producing abortion. 2. An agent that produces abortion.
Abortion. Expulsion from the uterus of and embryo or fetus prior to the stage of viability (20
weeks’ gestation or fetal weight <500g). A distinction made between abortion and premature
birth: premature infants are those born after the stage of viability but prior to 37 weeks.
Abortion may be either spontaneous (occurring from natural causes) or induced (artificial or
therapeutic). 2. The arrest of any action or process before its normal completion.
Acne. An inflammatory follicular, popular, and pustular eruption involving the pilosebaceous
apparatus.
Adjuvant therapy. Additional therapy given to enhance or extend primary therapy’s effect,
as in chemotherapy’s addition to a surgical regimen.
Amenorrhea. Absence or abnormal cessation of the menses.
Aphrodisiac. 1. Increasing sexual desire. 2. Anything that aroses or increases sexual desire.
Asthma. An inflammatory disease of the lungs characterized by reversible (in most cases)
airway obstruction. Originally, a term used to mean “difficult breathing”; now used to denote
bronchial asthma.
Boil. SYN furuncle
Bronchitis. Inflammation of the mucous membrane of the bronchial tubes.
Bronchitis. Inflammation of the mucous membrane of the bronchial tubes.
Bruise. An injury producing a hematoma or diffuse extravasation of blood without rupture of
skin.
Calculi. Plural of calculus.
Calculus. A concentration formed in any part of the body, most commonly in the passages of
the biliary and urinary tracts; usually composed of salts of inorganic or organic acids, or other
material such as cholesterol.
Cicatrization. The process of scar formation.
Cicatrizing agent. An agent causing or favouring cicatrisation.
Coitus. Sexual union between male and female.
Colic. 1. Relating to the colon. 2. Spasmodic pains in the abdomen. 3. In young infants,
paroxysms of gastrointestinal pain, with crying and irritability, due to a variety of causes, such
as swallowing of air, emotional upset, or overfeeding.
Contraception. An agent for the prevention of conception.
Diabetes. Either d. insipidus or d. mellitus, diseases having in common the symptom polyuria;
when used without qualification.
Diuretic. 1. Promoting the excretion of urine. 2. An agent that increases the amount of urine
excreated.
Dropsy. Old term for generalized edema, most often associated with cardiac failure.
Dysentery. A disease marked by frequent watery stools. Often with blood and mucus, and
characterized clinically by pain, tenesmus, fever, and dehydration.
Epilepsy. A chronic disorder characterized by paroxyamal brain dysfunction due to excessive
neuronal discharge, and usually associated with some alteration of consciousness. The clinical
manifestations of the attack may vary from complex abnormalities of behavior including
generalized or focal convulsions to momentary spells of impaired consciousness.
Eruption. 1. A breaking out, especially the appearance of lesions on the skin. 2. A rapidly
developing dermatosis of the skin or mucous membranes, especially when appearing as a
local manifestation of one of the exanthemata; an eruption is characterized, according to the
nature of lesion, as macular, popular, vesicular, nodular, etc. 3. The passage of a tooth through
the alveolar process and perforation of the gums.
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Erysipelas. A specific, acute, superficial cutaneous caused by β-hemolytic streptococci and
characterized by hot, red, edematous, brawny, and sharply defined eruptions; usually
accompanied by severe constitutional symptoms.
Expectorant. 1. Promoting secretion from the mucous membrane of the air passages or
facilitating its expulsion. 2. An agent that increases bronchial secretion and facilitates its
expulsion.
Furuncles. A localized pyrogenic infection, most frequently by Staphylococcus aureus,
originating deep in a hair follicle. SYN boil, furunculus.
Jaundice. A yellowish staining of the integument, sclerae, deeper tissues, and excretions with
bile pigments, resulting from increased levels in the plasma.
Keloid. A nodular, firm, movable, non encapsulated, often linear mass of hyperplastic, scar
tissue, tender and frequently painful, consisting of wide irregularly distributed bands of
collagen; occurs in the dermis and adjacent subcutaneous tissue, usually after trauma, surgery,
a burn, or severe cutaneous disease such as cystic acne, and is more common in blacks.
Liniment. A liquid preparation for external application or application to the gums; they may
be clear dispersion, suspensions, or emulsions, and are frequently applied by friction to the
skin; used as counterritants, rubefacients, anodynes, or cleansing agents.
Menses. Menstrual period.
Miscarriage. Spontaneous expulsion of the products of pregnancy before the middle of the
second trimester. SYN spontaneous abortion.
Pimple. A papule or small pustule; usually meant to denote an inflammatory lesion of acne.
Scar. Fibrous tissue replacing tissues destroyed by injury or disease.
Scurvy. A disease marked by inanition, debility, anemia, and edema of the dependent parts; a
spongy condition sometimes the ulceration of the gums and loss of teeth, hemorrhages and
poor wound healing; due to a diet lacking vitamin C.
Teratogenesis. The origin of mode of production of a malformed conceptus; the disturbed
growth processes involved in the production of a malformed neonate.
Teratogenic. 1. Relating to teratogenesis. 2. Causing abnormal prenatal development.
Tonic. In a state of continuous unremitting action; denoting especially a prolonged muscular
contraction.
Ulcer. A lesion through the skin or a mucous membrane resulting from loss of tissue, usually
with inflammation.
Whitlow. Purulent infection through a perionychial fold causing an abscess of the bulbous
distal end of a finger.
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List of Abreevations
5-HT- 5-hydroxytryptamine (serotonin)
A.S. - Specificity Attestation
AEHPLC- anionic exchange-high performance liquid chromatography
Cal- Calorie
cm-Centimeter
D.O.P.-Denomination of Protected Origin
DDT-Dichloridiphenyltrichloroethane
DMBA-Dimethyl bezoic acid
EROD-7-ethoxy resorufin O-deethylase
g-Gram
h- Hour
Ha-Hectare
HPTLC- High performance thin layer chromatography
I.G.P. - Indication of Protected Origin
IBA-Indole Butyric acid
INF-Interferon
Kcal- Kilocalorie
kg-Kilogram
L.S.-Longitudinal section
mg- Milligram
MIC-Minimum inhibitory concentration
Min-Minute
Mt-Metric
NAA-Napthlane-1-Acetic acid
nm- Nanometer
PAS- Periodic acid schiffs
Ppm- Parts per million
PTM- Primary thickening meristem
Qt-Quinton
Rf-Retention factor
T.S.-Transverse section
TLC: Thin layer chromatography
TNF- Tumor necrosing factor
TS- Thiosulphinates
VGA: Vanillin-glacial acid
О
C- Degree centigrade
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