Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Estudos http://aformulabr.com.br/qrcode/zeaxantinafv01.pdf ZEAXANTINA Nutracêutico antioxidante da saúde ocular DESCRIÇÃO Carotenóide de origem natural (frutas, folhas e vegetais) utilizado como suplemento alimentar. No organismo humano está presente em maior concentração na mácula, situada no centro da retina responsável pela visão central. MECANISMO DE AÇÃO Atua como filtro da luz solar protegendo a mácula ocular dos efeitos da luz ultravioleta ao aumentar a densidade do pigmento macular. Como antioxidante, protege as células dos danos oxidativos, reduzindo o risco de desenvolvimento de algumas doenças crônicas degenerativas, uma vez que o estresse oxidativo e a atuação dos radicais livres são fatores associados à iniciação e propagação do desenvolvimento destas doenças. INDICAÇÕES Antioxidante; Prevenção e tratamento da catarata; Auxiliar no tratamento da degeneração macular relacionada à idade (DMRI). DOSE USUAL Recomendação oral de 0,5 a 1,5mg de Zeaxantina, ao dia, podendo variar de acordo com a necessidade do paciente. SUGESTÕES DE FÓRMULAS Zeaxantina............................................................ 1mg Luteína ................................................................ 12mg Licopeno...............................................................10mg Zinco Quelato.......................................................15mg Selênio Quelato..................................................34mcg Modo de uso: 1 dose ao dia após o almoço. Indicação: Antioxidante. Luteína................... ............................................... 5mg Zeaxantina............................................................ 1mg Betacaroteno....................................................... 15mg Selênio Quelato................................................. 50mcg Modo de uso: 1 dose ao dia. Indicação: antioxidante; preventivo para DMRI PRINCIPAIS REFERÊNCIAS SOUZA, V.M.; JUNIOR, D.A. Ativos dermatológicos : democosméticos e Nutracêuticos. Edição especial 10 anos, volumes 1 a 8. São Paulo: Editora Pharmabooks, 2013. KRINSKY, N.I.; LANDRUM, J.T.; BONE, R.A. Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye. Annu Rev Nutr. V. 23, p. 171-201, 2003. Disponível em:< http://www.ncbi.nlm.nih.gov/pubmed/12626691>. Acesso em: 03 de novembro de 2015, às 17:59 ZEAXANTINA ESTUDOS CLÍNICOS Lutein and zeaxanthin dietary supplements raise macular pigment density and serum concentrations of these carotenoids in humans Age-related macular degeneration (AMD) is thought to be the result of a lifetime of oxidative insult that results in photoreceptor death within the macula. Increased risk of AMD may result from low levels of lutein and zeaxanthin (macular pigment) in the diet, serum or retina, and excessive exposure to blue light. Through its light-screening capacity and antioxidant activity, macular pigment may reduce photooxidation in the central retina. Lutein supplements, at 30 mg/d, were shown previously to increase serum lutein and macular pigment density in two subjects. In this study, we compared the effects of a range of lutein doses (2.4- 30 mg/d), as well as a high zeaxanthin dose (30 mg/d), on the serum and macular pigment in a series of experiments. Serum carotenoids were quantified by HPLC. Macular pigment densities were determined psychophysically. Serum lutein concentrations in each subject reached a plateau that was correlated with the dose (r = 0.82, P < 0.001). Plateau concentrations ranged from 2.8 x 10(-7) to 2.7 x 10(-6) mol/L. Zeaxanthin was less well absorbed than an equal lutein dose, resulting in plateaus of approximately 5 x 10(-7) mol/L. The rate of increase in macular pigment optical density was correlated with the plateau concentration of carotenoids in the serum (r = 0.58, P < 0.001), but not with the presupplementation optical density (r = 0.13, P = 0.21). The mean rate of increase was (3.42 +/- 0.80) x 10(5) mAU/d per unit concentration (mol/L) of carotenoids in the serum. It remains to be demonstrated whether lutein or zeaxanthin dietary supplements reduce the incidence of AMD. Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye Abstract: The macular region of the primate retina is yellow in color due to the presence of the macular pigment, composed of two dietary xanthophylls, lutein and zeaxanthin, and another xanthophyll, meso-zeaxanthin. The latter is presumably formed from either lutein or zeaxanthin in the retina. By absorbing blue-light, the macular pigment protects the underlying photoreceptor cell layer from light damage, possibly initiated by the formation of reactive oxygen species during a photosensitized reaction. There is ample epidemiological evidence that the amount of macular pigment is inversely associated with the incidence of age-related macular degeneration, an irreversible process that is the major cause of blindness in the elderly. The macular pigment can be increased in primates by either increasing the intake of foods that are rich in lutein and zeaxanthin, such as dark-green leafy vegetables, or by supplementation with lutein or zeaxanthin. Although increasing the intake of lutein or zeaxanthin might prove to be protective against the development of age-related macular degeneration, a causative relationship has yet to be experimentally demonstrated. Lutein and zeaxanthin status and risk of age-related macular degeneration PURPOSE:To investigate the relation between plasma concentrations of lutein and zeaxanthin and age-related macular degeneration in a group of elderly men and women.METHODS:The Wisconsin Age-Related Maculopathy Grading System was used to grade features of early and late macular degeneration in 380 men and women, aged 66 to 75 years, from Sheffield, United Kingdom. Fasting blood samples were taken to assess plasma concentrations of lutein and zeaxanthin.RESULTS:Risk of age-related macular degeneration (early or late) was significantly higher in people with lower plasma concentrations of zeaxanthin. Compared with those whose plasma concentrations of zeaxanthin were in the highest third of the distribution, people whose plasma concentration was in the lowest third had an odds ratio for risk of age-related macular degeneration of 2.0 (95% confidence interval [CI] 1.0-4.1), after adjustment for age and other risk factors. Risk of age-related macular degeneration was increased in people with the lowest plasma concentrations of lutein plus zeaxanthin (odds ratio [OR] 1.9, 95% CI 0.9-3.5) and in those with the lowest concentrations of lutein (OR 1.7, 95% CI 0.9-3.3), but neither of these relations was statistically significant.CONCLUSIONS:These findings provide support for the view that zeaxanthin may protect against agerelated macular degeneration. The potential role of dietary xanthophylls in cataract and age-related macular degeneration Abstract:The carotenoid xanthophylls, lutein and zeaxanthin, accumulate in the eye lens and macular region of the retina. Lutein and zeaxanthin concentrations in the macula are greater than those found in plasma and other tissues. A relationship between macular pigment optical density, a marker of lutein and zeaxanthin concentration in the macula, and lens optical density, an antecedent of cataractous changes, has been suggested. The xanthophylls may act to protect the eye from ultraviolet phototoxicity via quenching reactive oxygen species and/or other mechanisms. Some observational studies have shown that generous intakes of lutein and zeaxanthin, particularly from certain xanthophyll-rich foods like spinach, broccoli and eggs, are associated with a significant reduction in the risk for cataract (up to 20%) and for age-related macular degeneration (up to 40%). While the pathophysiology of cataract and age-related macular degeneration is complex and contains both environmental and genetic components, research studies suggest dietary factors including antioxidant vitamins and xanthophylls may contribute to a reduction in the risk of these degenerative eye diseases. Further research is necessary to confirm these observations. Lutein and zeaxanthin concentrations in rod outer segment membranes from perifoveal and peripheral human retina PURPOSE:In addition to acting as an optical filter, macular (carotenoid) pigment has been hypothesized to function as an antioxidant in the human retina by inhibiting the peroxidation of long-chain polyunsaturated fatty acids. However, at its location of highest density in the inner (prereceptoral) layers of the foveal retina, a specific requirement for antioxidant protection would not be predicted. The purpose of this study was to determine whether lutein and zeaxanthin, the major carotenoids comprising the macular pigment, are present in rod outer segment (ROS) membranes where the concentration of long-chain polyunsaturated fatty acids, and susceptibility to oxidation, is highest.METHODS:Retinas from human donor eyes were dissected to obtain two regions: an annular ring of 1.5- to 4-mm eccentricity representing the area centralis excluding the fovea (perifoveal retina) and the remaining retina outside this region (peripheral retina). ROS and residual (ROS-depleted) retinal membranes were isolated from these regions by differential centrifugation and their purity checked by polyacrylamide gel electrophoresis and fatty acid analysis. Lutein and zeaxanthin were analyzed by high-performance liquid chromatography and their concentrations expressed relative to membrane protein. Preparation of membranes and analysis of carotenoids were performed in parallel on bovine retinas for comparison to a nonprimate species. Carotenoid concentrations were also determined for retinal pigment epithelium harvested from human eyes.RESULTS:ROS membranes prepared from perifoveal and peripheral regions of human retina were found to be of high purity as indicated by the presence of a dense opsin band on protein gels. Fatty acid analysis of human ROS membranes showed a characteristic enrichment of docosahexaenoic acid relative to residual membranes. Membranes prepared from bovine retinas had protein profiles and fatty acid composition similar to those from human retinas. Carotenoid analysis showed that lutein and zeaxanthin were present in ROS and residual human retinal membranes. The combined concentration of lutein plus zeaxanthin was 70% higher in human ROS than in residual membranes. Lutein plus zeaxanthin in human ROS membranes was 2.7 times more concentrated in the perifoveal than the peripheral retinal region. Lutein and zeaxanthin were consistently detected in human retinal pigment epithelium at relatively low concentrations.CONCLUSIONS:The presence of lutein and zeaxanthin in human ROS membranes raises the possibility that they function as antioxidants in this cell compartment. The finding of a higher concentration of these carotenoids in ROS of the perifoveal retina lends support to their proposed protective role in age-related macular degeneration. REFERÊNCIAS BONE, R.A. et. al. Lutein and zeaxanthin dietary supplements raise macular pigment density and serum concentrations of these carotenoids in humans. J Nutr. V. 133,n. 4, p. 922-998, Apr 2003.Disponível em: < http://www.ncbi.nlm.nih.gov/pubmed/12672909>. Acesso em: 04 de novembro de 2015, às 11:50. KRINSKY, N.I.; LANDRUM, J.T.; BONE, R.A. Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye. Annu Rev Nutr. V. 23, p. 171-201, 2003. Disponível em:< http://www.ncbi.nlm.nih.gov/pubmed/12626691>. Acesso em: 03 de novembro de 2015, às 17:59. GALE, C.R. et. al. Lutein and zeaxanthin status and risk of age-related macular degeneration. Invest Ophthalmol Vis Sci. 2003 Jun;44(6):2461-5. Disponível em: http://www.ncbi.nlm.nih.gov/pubmed/12766044. Acesso em: 04 de Novembro de 2015, às 10:29. MOELLER, S.M.; JACQUES, P.F.; BLUMBERG, J.B. The potential role of dietary xanthophylls in cataract and age-related macular degeneration. J Am Coll Nutr. v. 19, n. 5,p. 522S-527S, Oct. 2000. Disponível em: < http://www.ncbi.nlm.nih.gov/pubmed/11023002>. Acesso em: 04 de Novembro de 2015, às 10:48. RAPP, L.M.; MAPLE, S.S.; CHOI; J.H. Lutein and zeaxanthin concentrations in rod outer segment membranes from perifoveal and peripheral human retina. Invest Ophthalmol Vis Sci. v. 41,n.5, p. 1200-1209, Apr 2000. Disponível em: < http://www.ncbi.nlm.nih.gov/pubmed/10752961>. Acesso em: 04 de Novembro de 2015, às 10:57.