The lens and retina of the human eye are exposed constantly to light and oxygen. In situ phototransduction and oxidative phosphorylation within photoreceptors produces a high level of phototoxic and oxidative related stress. Within the eye, the carotenoids lutein and zeaxanthin are present in high concentrations in contrast to other human tissues. We discuss the role of lutein and zeaxanthin in...

Lutein is the most abundant plant carotenoid and plays essential roles in photosystem assembly and stabilization, as well as protection against photostress. To date, only a few lutein biosynthesis genes have been identified in crop plants. In this study, the rice Cyt P450 gene CYP97A4 encoding a carotenoid β-ring hydroxylase was shown to be involved in lutein biosynthesis. The results revealed ...

Lutein, a yellow xanthophyll carotenoid found in egg yolks and many colorful fruits and vegetables, has gained public health interest for its putative role in visual performance and reducing the risk of age-related macular degeneration. The National Academies of Sciences, Engineering and Medicine's recommended Dietary Reference Intakes (DRIs) focus on preventing deficiency and toxicity, but the...

Lutein, a dihydroxy derivative of -carotene ( , -carotene), is the most abundant carotenoid in photosynthetic plant tissues where it plays important roles in light-harvesting complex-II structure and function. The synthesis of lutein from lycopene requires at least four distinct enzymatic reactions: and -ring cyclizations and hydroxylation of each ring at the C-3 position. Three carotenoid hydr...

Choroideremia is an incurable X-linked retinal degeneration caused by mutations in the gene encoding Rab escort protein-1. A group of clinically defined and genotyped patients were studied to determine: (1) the degree of rod and cone dysfunction and structural abnormality in the central retina and the level of macular pigment; and (2) the response of macular pigment and foveal vision to a 6 mon...

The bioavailability of carotenoids from kale was investigated by labeling nutrients in kale with 13C, feeding the kale to seven adult volunteers, and analyzing serial plasma samples for labeled lutein, beta-carotene, and retinol. Ingested doses of labeled carotenoids were 34 micromol for beta-carotene and 33 micromol for lutein. Peak plasma concentrations, areas under the plasma concentration-t...

AIM The current study aims to explore the possible molecular mechanism of hyperhomocysteinemia (HHcy) mediated atherosclerosis (AS) and to find an effective intervention method for AS. MATERIALS AND METHODS A total of 40 Wistar rats were equalized into four groups: blank control, HHcy, folacin intervention, and lutein intervention groups. HHcy rat models were established. The intervention gro...

Avian eggs are rich in carotenoids, which derive from maternal diet where they may be available in limiting amounts. Egg carotenoids may accomplish major roles in antioxidant protection or modulate physiological functions and growth, interfering with offspring redox status, potentially in a sex-dependent way. In this study of maternal effects in relation to sex and laying order of yellow-legged...