Lutein

Bioavailability of lutein from a lutein-enriched egg-yolk beverage and its dried re-suspended versions.[Pubmed:25017577]

Int J Food Sci Nutr. 2014 Nov;65(7):903-9.

Drying a fresh Lutein-enriched egg-yolk beverage would extend its shelf life, however, functional properties should not be affected. It was investigated whether consumption of a dried beverage containing Lutein-enriched egg-yolk significantly increases serum Lutein. One-hundred healthy young subjects participated in this 6-weeks randomized controlled study. Subjects consumed either a "plain" control beverage (n = 26), a fresh Lutein-enriched egg-yolk beverage (n = 25), a dried version of this beverage (n = 25), or a beverage composed of the dried individual components of the drink (n = 24). The fresh and both dried versions of the Lutein-enriched egg-yolk beverage were able to increase serum Lutein levels after 6 weeks of consumption (Lutein change: -38 +/- 47 nmol/L, +304 +/- 113 nmol/L, +148 +/- 79 nmol/L and +178 +/- 83 nmol/L for control, fresh, dried and combined dried group respectively; p < 0.001). No significant change in serum cholesterol level was seen in the beverages containing Lutein-enriched egg-yolk compared to the control drink.

Lutein, lycopene, and their oxidative metabolites in chemoprevention of cancer.[Pubmed:8538204]

J Cell Biochem Suppl. 1995;22:236-46.

Numerous epidemiological studies have demonstrated that consuming large quantities of fruits and vegetables reduces the risk for several types of human cancers. Carotenoids are abundant in fruits and vegetables and have been extensively studied as cancer preventive agents. A proposed mechanism of action for the protective effect of carotenoids against cancer is based on their antioxidant capability. Recently, we have isolated and characterized 14 new carotenoids, including seven metabolites from the extracts of human serum/plasma. This brings the total number of identified blood carotenoids to 21. Lutein and lycopene, abundant in most fruits and vegetables as well as human serum, have been shown to possess strong antioxidant capability. Among the metabolites of Lutein, four results from oxidation and two from non-enzymatic dehydration. The metabolite of lycopene has been identified as 5,6-dihydroxy-5,6-dihydrolycopene, which apparently results from oxidation of lycopene to an intermediate, lycopene epoxide. This intermediate may undergo metabolic reduction to form the lycopene metabolite. Although in vivo oxidation of Lutein to its metabolites has been demonstrated based on data obtained from two human studies, in vivo oxidation of lycopene to its metabolite has not yet been established. Recent preliminary studies involving healthy subjects ingesting purified Lutein and zeaxanthin (a dietary dihydroxycarotenoid isomeric to Lutein) are presented. We propose a possible antioxidant mechanism of action for Lutein and lycopene that leads to formation of the oxidation products of these promising chemopreventive agents.

Isolation of beta-carotene, alpha-carotene and lutein from carrots by countercurrent chromatography with the solvent system modifier benzotrifluoride.[Pubmed:25728658]

J Chromatogr A. 2015 Apr 3;1388:119-25.

A carotenoid purification method with dual-mode countercurrent chromatography (CCC) for beta-carotene, alpha-carotene and Lutein from a fresh carrot extract was developed. The fluorinated liquid benzotrifluoride (IUPAC name: (trifluoromethyl)benzene) was used as a novel modifier in the non-aqueous ternary solvent system n-hexane/benzotrifluoride/acetonitrile. The ternary phase diagram of the type I solvent system was used to select two-phase solvent mixtures which enabled an efficient preparative separation of alpha-carotene, beta-carotene and Lutein from concomitant pigments in crude carrot extract. By means of the modifier, high separation factors (alpha >/= 1.2) were obtained, allowing baseline resolution between alpha-carotene and beta-carotene due to specific chemical interactions such as pi-pi molecular interactions. After optimizing the injection step with a pseudo-ternary phase diagram, 51 mg of beta-carotene, 32 mg of alpha-carotene and 4 mg of Lutein could be isolated from 100.2mg crude carrot extract in a short time and with high purities of 95% and 99% by using dual-mode CCC, respectively. Temperatures > 22 degrees C had a negative impact on the separation of alpha-carotene and beta-carotene.

Role of lutein and zeaxanthin in visual and cognitive function throughout the lifespan.[Pubmed:25109868]

Nutr Rev. 2014 Sep;72(9):605-12.

The relationship between Lutein and zeaxanthin and visual and cognitive health throughout the lifespan is compelling. There is a variety of evidence to support a role for Lutein and zeaxanthin in vision. Lutein's role in cognition has only recently been considered. Lutein and its isomer, zeaxanthin, are taken up selectively into eye tissue. Lutein is the predominant carotenoid in human brain tissue. Lutein and zeaxanthin in neural tissue may have biological effects that include antioxidation, anti-inflammation, and structural actions. In addition, Lutein and zeaxanthin may be protective against eye disease because they absorb damaging blue light that enters the eye. In pediatric brains, the relative contribution of Lutein to the total carotenoids is twice that found in adults, accounting for more than half the concentration of total carotenoids. The greater proportion of Lutein in the pediatric brain suggests a need for Lutein during neural development as well. In adults, higher Lutein status is related to better cognitive performance, and Lutein supplementation improves cognition. The evidence to date warrants further investigation into the role of Lutein and zeaxanthin in visual and cognitive health throughout the lifespan.

Effects of a lutein supplement on the plasma lutein concentration and macular pigment in patients with central serous chorioretinopathy.[Pubmed:25074771]

Invest Ophthalmol Vis Sci. 2014 Jul 29;55(8):5238-44.

PURPOSE: To investigate the effects of Lutein supplementation on plasma Lutein concentrations and the macular pigment optical density (MPOD) in central serous chorioretinopathy (CSC). METHODS: In this double-masked placebo-controlled study, 20 patients received Lutein 20 mg/d and 19 received placebo. The plasma Lutein concentration and MPOD using autofluorescence spectrometry (density unit, DU) were measured at baseline and 1 and 4 months. RESULTS: The mean plasma Lutein concentrations and MPOD values in the Lutein and control groups, respectively, were 91.5 and 78.2 ng/mL and 0.444 and 0.437 DU at baseline; 204.9 and 79.3 ng/mL and 0.460 and 0.442 DU at 1 month; and 228.0 and 78.4 ng/mL and 0.441 and 0.421 DU at 4 months. The plasma concentration in the Lutein group was significantly higher than in controls at 1 and 4 months (P < 0.0001 for both comparisons); however, the MPOD values did not differ significantly between groups at 1 (P = 0.479) or 4 months (P = 0.883). In patients with a plasma Lutein concentration below the mean level in 20 age-matched healthy subjects (mean 105.3 ng/mL; n = 13 in Lutein group, n = 15 in control group), the control MPOD values significantly (P = 0.0430) decreased at 4 months (mean baseline, 0.437 DU; 4 months, 0.404 DU). The MPOD in the Lutein group remained at the baseline level (mean baseline, 0.426 DU; 4 months, 0.438 DU) (P = 0.6542). CONCLUSIONS: The MPOD did not increase in patients with CSC with short-term Lutein supplementation; however, among patients with low plasma Lutein, supplemental Lutein prevented a decline in MPOD that was observed in control subjects (www.umin.ac.jp/ctr number, UMIN000005849).