Bioaccessibility, cellular uptake and transport of luteins and assessment of their antioxidant activities.

A rapid method for producing 9Z- and 13'Z-isomers from all-E-lutein was developed using I-TiO2 as catalyst. In a simulated in vitro gastrointestinal digestion model, both trans-cis isomerization of all-E-lutein and cis-trans isomerization of Z-luteins occurred during the intestinal phase. The bioaccessibility of all isomers was between 14 and 23%, and it was higher for Z-luteins. In a Caco-2 cell monolayer model, all isomers were relatively stable during cellular uptake and transport across the membrane as no significant isomerization and degradation was detected, but all-E-lutein exhibited significantly higher cellular uptake and transport efficiencies. These results suggest that Z-luteins found in human plasma may likely be formed before intestinal absorption. 13'Z-Lutein also exhibited highest antioxidant activity in FRAP, DPPH and ORAC-L assays, but no significant difference in cell-based antioxidant assay compared with other isomers. Future studies on the different antioxidant activities of cis isomers of lutein in vivo will provide further explanation.

Assessment of dietary lutein, zeaxanthin and lycopene intakes and sources in the Spanish survey of dietary intake (2009-2010).

We assessed the intake and major dietary sources of lutein, zeaxanthin and lycopene (non-provitamin A carotenoids) in Spain using food consumption data from the Spanish National Dietary Intake Survey (2009-2010). Three-day diaries and one 24-h recall were used to collect dietary data and a software application that includes HPLC data was used. Average intake of those carotenoids was 4290.8 µg/d (67.1% total carotenoid intake), mainly from vegetables (3414.0 µg/d), followed by fruits (393.5 µg/d), oils/fats (204.0 µg/d) and eggs/egg products (170.0 µg/d). Main sources of lutein and zeaxanthin were vegetables (62.9% total diet, 1235.2 µg/person/d). Lycopene intake was 3055.6 µg/d (71.2% of non-provitamin A carotenoids), mainly from tomato and by-products (86.3%) and watermelon. Red- and orange-colored fruits and vegetables were the major contributors of non-provitamin carotenoids (3219.0 µg/person/d). Balanced diets should favor fruits and vegetables over other dietary sources (oils, eggs, processed foods) that contain components to be consumed with moderation.

Ocular nutritional supplements: are their ingredients and manufacturers' claims evidence-based?

PURPOSE: To compare ingredients contained in top-selling brands of ocular nutritional supplements with the Age-Related Eye Disease Study (AREDS) and AREDS2 formulae and investigate the validity of claims made by manufacturers of leading brands of ocular nutritional supplements. DESIGN: Descriptive. PARTICIPANTS: None. METHODS: We examined the 5 top-selling brands of ocular nutritional supplements in the United States according to dollar sales tracked by SymphonyIRI (Waltham, MA) from June 2011 to June 2012. We reviewed the ingredients and manufacturer claims of 11 ocular nutritional supplements on the companies' consumer information websites; the ingredients were compared with those contained in the AREDS and AREDS2 formulae. MAIN OUTCOME MEASURES: Proportion of ocular nutritional supplements that contained the same ingredients, in the same doses, as the AREDS or AREDS2 formula; proportion of nutritional supplements with unsubstantiated claims made by the manufacturer. RESULTS: All of the ocular nutritional supplements contained the ingredients from the AREDS or AREDS2 formula; 36% (4/11) of the supplements contained equivalent doses of AREDS or AREDS2 ingredients; 55% (6/11) included some information about the AREDS on their consumer information websites. Product descriptions from 4 of the 11 supplements (36%) stated that the supplements were important to maintain general eye health; none of these supplements duplicated the AREDS or AREDS2 formula. All the individual supplements claimed to "support," "protect," "help," or "promote" vision and eye health, but none specified that there is no proven benefit in using nutritional supplements for primary prevention of eye disease. CONCLUSIONS: The majority of top-selling ocular nutritional supplements did not contain the identical ingredient dosages of the AREDS or AREDS2 formula and had product description claims that lacked level 1 evidence, underscoring the importance of ophthalmologists educating their patients on the evidence-based role of nutritional supplements in the management of eye health.

Safety assessment of lutein and zeaxanthin (Lutemax 2020): subchronic toxicity and mutagenicity studies.

Lutein and zeaxanthin, naturally occurring carotenoids, have shown to reduce the risk of cataracts and age-related macular degeneration. Lutemax 2020 is a lutein and zeaxanthin (including meso-isomer) enriched product obtained from Marigold flowers (Tagetes erecta L). The objective of the present study was to investigate adverse effects, if any, of Lutemax 2020 in acute and subchronic toxicity, and mutagenicity studies. In acute toxicity study in rats no lethality was noted at 2000 mg Lutemax 2020/kg body weight (bw). In the subchronic study, Wistar rats (10/sex/group) were administered (gavage) lutein/zeaxanthin concentrate at dose levels of 0, 4, 40 and 400mg/kg bw/day for 90-days. Compared with the control group, administration of lutein/zeaxanthin concentrate did not result in any toxicologically significant treatment-related changes in clinical observations, ophthalmic examinations, body weights, body weight gains, feed consumption, and organ weights. No toxicologically relevant findings were noted in urinalysis, hematology or clinical biochemistry parameters at the end of the treatment or recovery period. Terminal necropsy did not reveal any treatment-related gross or histopathology findings. The results of mutagenicity testing in Salmonella typhimurium did not reveal any genotoxicity. The no observed-adverse-effect level (NOAEL) for lutein/zeaxanthin concentrate was determined as 400mg/kg bw/day, the highest dose tested.

Assessment of carotenoid production by Dunaliella salina in different culture systems and operation regimes.

The effect of operation regime and culture system on carotenoid productivity by the halotolerant alga Dunaliella salina has been analyzed. Operation strategies tested included batch and semi continuous regime, as well as a two-stage approach run simultaneously in both, open tanks and closed reactor. The best results were obtained with the closed tubular photobioreactor. The highest carotenoid production (328.8 mg carotenoid l⁻¹ culture per month) was achieved with this culture system operated following the two-stage strategy. Also, closed tubular photobioreactor provided the highest carotenoid contents (10% of dry weight) in Dunaliella biomass and ß-carotene abundance (90% of total carotenoids) as well as the highest 9-cis to all-trans ß-carotene isomer ratio (1.5 at sunrise).

Dipalmitoylphosphatidylcholine membranes modified with carotenoid pigment lutein: experiment versus Monte Carlo simulation study of the membrane organization.

Organization of bilayer lipid membrane formed with dipalmitoylphosphatidylcholine and containing a xanthophyll pigment lutein was studied by both the Monte Carlo simulation and UV-Vis absorption spectroscopy. The simulations were based on ten-state Pink model. The proposed model consisted of two monolayers represented by a two-dimensional triangular lattice with vacancies. The orientation and aggregation state of lutein, obtained from the analysis of the spectroscopic measurements, were used to calibrate intermolecular interactions in the model. In accordance with the experimental data, the model allows two orientations of lutein molecules: one spanning the membrane and the other parallel to its plane. The influence of the intermolecular interactions on the main phase transition as well as on the aggregation of lutein molecules is discussed. The analysis of the model enables us to learn about molecular mechanisms that govern the effects of lutein on the membrane properties as well as the effects of the lipid matrix on lutein organization in the membrane. A concept is discussed according to which increasing domination of parallel lutein orientation, observed at high temperatures, can protect the membrane against penetration by water molecules and reactive oxygen species and against loss of the membrane compactness, especially in the regions of oxidized acyl chains.