Effect of Carotenoid Supplemented Formula on Carotenoid Bioaccumulation in Tissues of Infant Rhesus Macaques: A Pilot Study Focused on Lutein

Recent advances in carotenoid absorption, distribution, and elimination

Carotenoids are a class of pigments with antioxidant properties synthesized by photosynthetic and heterotrophic organisms. Humans can store carotenoids in their intact form or cleave them enzymatically to apocarotenoids such as vitamin A, a hormone-like nutrient with crucial roles in gene expression and vision. Clinical and preclinical studies suggest that the consumption of diets rich in carotenoids attenuate cardiometabolic diseases, some types of cancer, neurodegenerative disorders, and inflammatory conditions. The bioactive properties of carotenoids depend, at least in part, on their accumulation in target tissues. However, the pathways that drive carotenoid absorption, delivery, and accumulation in tissues remain largely uncharacterized. This review provides a critical overview of the experimental models utilized to monitor carotenoid homeostasis in mammals. We also delve into recent findings concerning carotenoid intestinal uptake, bodily distribution, cellular uptake, and intracellular trafficking. Finally, we discuss the physiological relevance of a fecal carotenoid elimination pathway that operates independently of carotenoid enzymatic cleavage. Establishing the players governing carotenoid biodistribution and elimination is essential to maximize the bioactive properties of carotenoids in humans to prevent chronic diseases.

Comparative Study of Human Milk and Infant Formulas at Different Stages Based on Dynamic In Vitro Infant Gastrointestinal Digestion: The Effect of Polar Lipids on Lutein Digestion

The efficiency of the absorption and digestion of lutein in infant formulas (IFs) is remarkably lower than that in human milk. This work compared the simulated in vitro dynamic digestive characteristics of lutein in three stages of human milk and six IFs, with a special emphasis on how polar lipids affect lutein digestion. Compared with colostrum (CM), IF2 had a significantly higher lutein loss rate but significantly lower micellarization and bioaccessibility rates. In CM, the morphology of milk fat globules (MFGs) remained visible after digestion; the phospholipid globular membrane structure can be observed after 180 min of intestinal digestion, and MFGs remained in a spherical form in micelles. Lipidomic analysis precisely quantified 18 significantly different lipids, including cholesterol, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphatidic acid, and phosphatidylglycerol, between CM and IF2 micelles, suggesting that these lipids may influence the micellarization of lutein. In summary, polar lipids play an important role in the protection of lutein and the facilitation of lutein micellarization. These findings also provide a certain reference for the adjustment of IF formulations.

Characterization of the interindividual variability of lutein and zeaxanthin concentrations in the adipose tissue of healthy male adults and identification of combinations of genetic variants associated with it

Lutein (L) and zeaxanthin (Z) are involved in visual function and could prevent age-related macular degeneration and chronic diseases and improve cognitive performances. Adipose tissue is the main storage site for these xanthophylls (Xanth). The factors affecting their concentrations in this tissue remain poorly understood but in animal models, genetic variations in apolipoprotein E and β-carotene oxygenase 2 have been associated with adipose tissue L concentration. Therefore, the aims of this study were to better characterize the interindividual variability of adipose tissue Xanth concentration and to identify single nucleotide polymorphisms (SNPs) associated with it. Periumbilical subcutaneous adipose tissue samples were collected on 6 occasions in 42 healthy adult males and L and Z concentrations were measured by HPLC. Participants had their whole genome genotyped and the associations of 3589 SNPs in 49 candidate genes with the concentrations of L and Z were measured. Mean L and Z concentrations were 281 ± 27 and 150 ± 14 nmol g-1 proteins, respectively. There was no significant correlation between plasma and adipose tissue Xanth concentrations, although the correlation for L approached significance (Pearson's r = 0.276, p = 0.077). Following univariate filtering, 109 and 97 SNPs were then entered into a partial least squares regression analysis to identify the combination of SNPs that explained best adipose tissue concentration of L and Z, respectively. A combination of 7 SNPs in ELOVL5, PPARG, ISX and ABCA1, explained 58% of the variability in adipose tissue L concentration while 11 SNPs located in or near PPARG, ABCA1, ELOVL5, CXCL8, IRS1, ISX, MC4R explained 53% of the variance in adipose tissue Z concentration. This suggests that some genetic variations influence the concentrations of these Xanth in adipose tissue and could therefore indirectly influence the health effects of these compounds. Clinical Trial Registry: https://ClinicalTrials.gov registration number NCT02100774.

Lutein supplementation for early-life health and development: current knowledge, challenges, and implications

Macular carotenoids, which consist of lutein, zeaxanthin, and meso-zeaxanthin, are dietary antioxidants and macular pigments in the eyes, protecting the macula from light-induced oxidative stress. Lutein is also the main carotenoid in the infant brain and is involved in cognitive development. While a few articles reviewed the role of lutein in early health and development, the current review is the first that focuses on the outcomes of lutein supplementation, either provided to mothers or to infants. Additionally, lutein status and metabolism during pregnancy and lactation, factors that limit the potential application of lutein as a nutritional intervention, and solutions to overcome the limitation are also discussed. In brief, the lutein intake in pregnant and lactating women in the United States may not be optimal. Furthermore, preterm and formula-fed infants are known to have compromised lutein status compared to term and breast-fed infants, respectively. While lutein supplementation via both maternal and infant consumption improves lutein status in infants, the application of lutein as a nutritional intervention may be compromised by its low bioavailability. Various encapsulation techniques have been developed to enhance the delivery of lutein in adult animals or human but should be further evaluated in neonatal models.

Maternal High-Fat Diet Consumption in Sprague Dawley Rats Compromised the Availability and Altered the Tissue Distribution of Lutein in Neonatal Offspring

Lutein, the most abundant carotenoid in the infant eye and brain, is critical for their visual and cognitive development. Due to its lipophilic nature, a high adiposity may affect the tissue distribution of lutein. The aim of the study was to determine the impacts of a maternal high-fat diet (HFD) consumption on the status of lutein in the neonatal offspring. Female Sprague Dawley rats (n = 6) were fed a normal fat diet (NFD) or a HFD for 8 weeks before mating, and they were switched to an NFD or an HFD containing the same concentration of lutein ester during gestation and lactation. Rat pups (n = 7/group/time) were euthanized on postnatal day 2 (P2), P6, P11, and P20 for measuring tissue lutein concentrations. No significant difference in maternal lutein intake was found between the two groups. At both P6 and P11, a significantly lower lutein concentration was noted in the milk samples separated from the stomach of HFD pups than the concentration in the samples from the NFD pups; the HFD group showed a significantly lower lutein concentration in the liver. At P11, the HFD pups exhibited a significantly lower lutein concentration in the eye, brain, and brown adipose tissue accompanied with a significantly higher lutein concentration and mass in the visceral white adipose tissue. The study was the first to provide evidence that maternal HFD consumption resulted in a compromised availability and altered distribution of lutein in the neonatal offspring.

Analysis of macular carotenoids in the developing macaque retina: The timeline of macular pigment development

In the mature retina, the components of the macular pigment, lutein (L), R,R-zeaxanthin (RRZ), R,S-zeaxanthin (RSZ, meso-zeaxanthin) are most concentrated in the central macula. L and RRZ are of dietary origin but RSZ is produced in situ from L. The relative proportions of L and Z isomers vary across the retina with eccentricity in the adult retina. Early reports have shown that during development, the proportions of L and Z isomers undergo changes as the total pigment levels increase. The methods described here demonstrate the unique utility of chiral phase HPLC to measure the amounts of L, RRZ, and RSZ, discriminating between the two zeaxanthin stereoisomers. In three concentric retinal sections of macaque retinas chiral phase HPLC has been employed to document the developmental changes in the distribution of each L, RSZ, and RRZ during the period just prior to full term gestation through 19 months after birth. The net rate of accumulation of carotenoids within the central retina during the first 20 months is quasi-linear and fit by a linear regression. During development, the rate of transport of L (0.12 (±0.033)ngmm^-2mo^-1 (SE)) into the central 2mm of the retina is double that of RRZ (0.062 (±0.02)ngmm^-2mo^-1 (SE)). The rate of accumulation of RSZ (0.06 (±0.01)ngmm^-2mo^-1 (SE)) is comparable to that of RRZ. In the peripheral retina, the rates of accumulation of L and RRZ are not correlated with increasing age, whereas accumulation of RSZ does correlate with age. The changing proportions of L to Z isomers in the central retina during development are explained by the rates for carotenoid accumulation within the central retina. At birth, the macular pigment in the central retina is dominated by L and RRZ, 0.35±0.11 and 0.21±0.054ngmm^-2. In the central retina, RSZ was rarely detected in the youngest tissues analyzed. It can be estimated to represent 6% of the total macular pigment (0.033±0.11ngmm^-2) at birth based on extrapolation from measurements in the peripheral retina and the ratio of L/(RRZ+RSZ) is ≈1.5. At maturity, the concentrations for L, RRZ, and RSZ in the central macaque retina are estimated to be 1.7, 1.8 and 1.08ngmm^-2, with L/(RRZ+RSZ) being 0.6.

Fenretinide inhibits vitamin A formation from β-carotene and regulates carotenoid levels in mice

N-[4-hydroxyphenyl]retinamide, commonly known as fenretinide, a synthetic retinoid with pleiotropic benefits for human health, is currently utilized in clinical trials for cancer, cystic fibrosis, and COVID-19. However, fenretinide reduces plasma vitamin A levels by interacting with retinol-binding protein 4 (RBP4), which often results in reversible night blindness in patients. Cell culture and in vitro studies show that fenretinide binds and inhibits the activity of β-carotene oxygenase 1 (BCO1), the enzyme responsible for endogenous vitamin A formation. Whether fenretinide inhibits vitamin A synthesis in mammals, however, remains unknown. The goal of this study was to determine if the inhibition of BCO1 by fenretinide affects vitamin A formation in mice fed β-carotene. Our results show that wild-type mice treated with fenretinide for ten days had a reduction in tissue vitamin A stores accompanied by a two-fold increase in β-carotene in plasma (P < 0.01) and several tissues. These effects persisted in RBP4-deficient mice and were independent of changes in intestinal β-carotene absorption, suggesting that fenretinide inhibits vitamin A synthesis in mice. Using Bco1-/- and Bco2-/- mice we also show that fenretinide regulates intestinal carotenoid and vitamin E uptake by activating vitamin A signaling during short-term vitamin A deficiency. This study provides a deeper understanding of the impact of fenretinide on vitamin A, carotenoid, and vitamin E homeostasis, which is crucial for the pharmacological utilization of this retinoid.

Early Pediatric Benefit of Lutein for Maturing Eyes and Brain-An Overview

Lutein is a dietary carotenoid preferentially accumulated in the eye and the brain in early life and throughout the life span. Lutein accumulation in areas of high metabolism and oxidative stress such as the eye and the brain suggest a unique role of this ingredient during the development and maturation of these organs of common embryological origin. Lutein is naturally provided to the developing baby via the cord blood, breast milk and then infant diet. The presence of this carotenoid depends on fruit and vegetable intakes and its bioavailability is higher in breastmilk. This paper aims to review the anatomical development of the eye and the brain, explore the presence and selective deposition of lutein in these organs during pregnancy and infancy and, based on its functional characteristics, present the latest available research on the beneficial role of lutein in the pediatric population. The potential effects of lutein in ameliorating conditions associated with increase oxidative stress such as in prematurity will be also addressed. Since consumption of lutein rich foods falls short of government guidelines and in most region of the world infant formulas lack this bioactive, dietary recommendations for pregnant and breastfeeding women and their child can help to bridge the gap.

Dietary tomato inhibits angiogenesis in TRAMP prostate cancer but is not protective with a Western-style diet in this pilot study

Prostate cancer (PCa) remains the second most diagnosed cancer worldwide. Higher body weight is associated with chronic inflammation, increased angiogenesis, and treatment-resistant tumor phenotypes. Dietary tomato reduces PCa risk, which may be due to tomato inhibition of angiogenesis and disruption of androgen signaling. This pilot study investigated the interplay between tomato powder (TP), incorporated into control (CON) and obesogenic (OB) diets, and PCa tumor growth and blood perfusion over time in a transgenic model of PCa (TRAMP). Ultrasound microvessel imaging (UMI) results showed good agreement with gold-standard immunohistochemistry quantification of endothelial cell density, indicating that this technique can be applied to non-invasively monitor tumor blood perfusion in vivo. Greater body weight was positively associated with tumor growth. We also found that TP significantly inhibited prostate tumor angiogenesis but that this inhibition differentially affected measured outcomes depending on CON or OB diets. TP led to reduced tumor growth, intratumoral inflammation, and intratumoral androgen-regulated gene expression (srd5a1, srd5a2) when incorporated with the CON diet but greater tumor growth and intratumoral gene expression when incorporated with the OB diet. Results from this study show that protective benefits from dietary tomato are lost, or may become deleterious, when combined with a Western-style diet.

Spatiotemporal biodistribution of α-tocopherol is impacted by the source of 13C-labeled α-tocopherol in mice following a single oral dose

Natural (RRR-) α-tocopherol (αT) is more bioactive than synthetic (all racemic, all rac-) αT, but not enough is known about the tissue kinetics of the 2 αT sources. We examined the time-course bioaccumulation of natural versus synthetic αT in tissues of young, marginally vitamin E-deficient mice using ¹³C-RRR-αT or ¹³C-all rac-αT tracers. In experiment 1, 3-week old male wild-type mice were fed a vitamin E-deficient diet for 0, 1, 2, or 3 weeks (n = 5/time point). Tissue αT levels were analyzed by HPLC-PDA. Feeding a vitamin E-deficient diet for up to 3 weeks decreased total αT concentrations in all analyzed tissues except the brain, which maintained its αT level. In experiment 2, a 2-week αT-depletion period was followed by administration of a single oral dose of 0.5 mg of ¹³C-RRR-αT or ¹³C-all rac-αT. At 12 hr, 1, 2, and 4 days post-dose, serum and multiple tissues were collected (n = 3/time point). αT was quantified by HPLC-PDA, and ¹³C-αT enrichment was determined by LC-MS. Both sources of ¹³C-αT reached maximum serum levels at 12 hr post-dose. ¹³C-RRR-αT levels were significantly higher than ¹³C-all rac-αT in serum at 1 d post-dose, and in heart, lungs, and kidney at 2d post-dose. In brain, ¹³C-RRR-αT concentrations were significantly higher than ¹³C-all rac-αT at 2 and 4 d post-dose. At 4 d post-dose, ¹³C-αT levels were similar between the 2 sources in examined tissues except for brain and adipose tissue where ¹³C-RRR-αT was higher. In conclusion, αT bioaccumulation over time varied substantially depending on αT source and tissue type.

Potential health benefits of carotenoid lutein: An updated review

Carotenoids in food substances are believed to have health benefits by lowering the risk of diseases. Lutein, a carotenoid compound, is one of the essential nutrients available in green leafy vegetables (kale, broccoli, spinach, lettuce, and peas), along with other foods, such as eggs. As nutrition plays a pivotal role in maintaining human health, lutein, as a nutritional substance, confers promising benefits against numerous health issues, including neurological disorders, eye diseases, skin irritation, etc. This review describes the in-depth health beneficial effects of lutein. As yet, a minimal amount of literature has been undertaken to consider all its promising bioactivities. The step-by-step biosynthesis of lutein has also been taken into account in this review. Besides, this review demonstrates the drug interactions of lutein with β-carotene, as well as safety concerns and dosage. The potential benefits of lutein have been assessed against neurological disorders, eye diseases, cardiac complications, microbial infections, skin irritation, bone decay, etc. Additionally, recent studies ascertained the significance of lutein nanoformulations in the amelioration of eye disorders, which are also considered in this review. Moreover, a possible approach for the use of lutein in bioactive functional foods will be discussed.

Z-Isomers of Astaxanthin Exhibit Greater Bioavailability and Tissue Accumulation Efficiency than the All-E-Isomer

The purpose of the present study was to clarify the differences in the bioavailability and tissue accumulation efficiency between (all-E)- and (Z)-astaxanthin. Astaxanthin with a high proportion of the Z-isomer (especially rich in the 9Z- and 13Z-isomers) was prepared from (all-E)-astaxanthin by thermal treatment and solid-liquid separation. The all-E-isomer- or Z-isomer-rich diet was fed to male rats for 2 weeks. After the feeding period, blood and tissue samples were collected, and their astaxanthin levels were evaluated. The Z-isomer-rich astaxanthin diet resulted in higher levels of astaxanthin in blood and many tissues (in particular, skin, lung, prostate, and eye) compared to the all-E-isomer-rich diet. Moreover, the Z-isomer-rich diet enhanced the level of the 13Z-isomer in blood and tissues rather than that of the 9Z-isomer. These results strongly supported that astaxanthin Z-isomers have greater bioavailability and tissue accumulation efficiency than the all-E-isomer. Moreover, (13Z)-astaxanthin would have higher bioavailability and tissue accumulation than the other isomers.

Inhibitory efficacy of lutein on adipogenesis is associated with blockage of early phase regulators of adipocyte differentiation

A comprehensive molecular mechanistic role of lutein on adipogenesis is not well understood. The present study focused to evaluate the effect of lutein at the early and late phase of adipocyte differentiation in vitro using a 3T3-L1 cell model. The effect of purified carotenoid on the viability of normal and differentiated 3T3-L1 cells was analyzed by WST-1 assay. Oil Red O and Nile red staining were employed to observe lipid droplets in mature adipocytes. The effect of lutein on gene and protein expression of major transcription factors and adipogenic markers was analyzed by RT-PCR and western blotting, respectively. The role of lutein on mitotic clonal expansion was analyzed by flow cytometry. The results showed a significant reduction (p < 0.05) in the accumulation of lipid droplets in lutein-treated (5 μM) cells. Inhibition in lipid accumulation was associated with down-regulated expression of CEBP-α and PPAR-γ at gene and protein levels. Subsequently, lutein repressed gene expression of FAS, FABP4, and SCD1 in mature adipocytes. Interestingly, it blocks the protein expression of CEBP-α and PPAR-γ in the initial stages of adipocyte differentiation. This early-stage inhibition of adipocyte differentiation is linked with repressed phosphorylation AKT and ERK. Further, upregulated cyclin D and down-regulated CDK4 and CDK2 in lutein treated adipocytes enumerate its role in delaying the cell cycle progression at the G0/G1 phase. Our results emphasize that adipogenesis inhibitory efficacy of lutein is potentiated by halting early phase regulators of adipocyte differentiation, which strengthens the competency of lutein besides its inevitable presence in the human body.

Synthetic α-Tocopherol, Compared with Natural α-Tocopherol, Downregulates Myelin Genes in Cerebella of Adolescent Ttpa-null Mice

BACKGROUND

Vitamin E (α-tocopherol; α-T) deficiency causes spinocerebellar ataxia. α-T supplementation improves neurological symptoms, but little is known about the differential bioactivities of natural versus synthetic α-T during early life.

OBJECTIVE

We assessed the effects of dietary α-T dose and source on tissue α-T accumulation and gene expression in adolescent α-tocopherol transfer protein-null (Ttpa-/-) mice.

METHODS

Three-week-old male Ttpa-/- mice (n  = 7/group) were fed 1 of 4 AIN-93G-based diets for 4 wk: vitamin E deficient (VED; below α-T limit of detection); natural α-T, 600 mg/kg diet (NAT); synthetic α-T, 816 mg/kg diet (SYN); or high synthetic α-T, 1200 mg/kg diet (HSYN). Male Ttpa+/+ littermates fed AIN-93G [75 mg synthetic α-T (CON)] served as controls (n  = 7). At 7 wk of age, tissue α-T concentrations and stereoisomer profiles were measured for all groups. RNA-sequencing was performed on cerebella of Ttpa-/- groups.

RESULTS

Ttpa-/- mice fed VED had undetectable brain α-T concentrations. Cerebral cortex α-T concentrations were greater in Ttpa-/- mice fed NAT (9.1 ± 0.7 nmol/g), SYN (10.8 ± 1.0 nmol/g), and HSYN (13.9 ± 1.6 nmol/g) compared with the VED group but were significantly lower than in Ttpa+/+ mice fed CON (24.6 ± 1.2 nmol/g) (P < 0.001). RRR-α-T was the predominant stereoisomer in brains of Ttpa+/+ mice (∼40%) and Ttpa-/- mice fed NAT (∼94%). α-T stereoisomer composition was similar in brains of Ttpa-/- mice fed SYN and HSYN (2R: ∼53%; 2S: ∼47%). Very few of the 16,774 genes measured were differentially expressed. However, compared with the NAT diet, HSYN significantly downregulated 20 myelin genes, including 2 transcription factors: SRY-box transcription factor 10 (Sox10) and myelin regulatory factor (Myrf), and several downstream target genes (false discovery rate <0.05).

CONCLUSIONS

High-dose synthetic α-T compared with natural α-T alters myelin gene expression in the adolescent mouse cerebellum, which could lead to morphological and functional abnormalities later in life.

Lutein across the Lifespan: From Childhood Cognitive Performance to the Aging Eye and Brain

Lutein is a non-provitamin A dietary carotenoid found in dark green leafy vegetables, corn, eggs, and avocados. Among the carotenoids, lutein and its isomer, zeaxanthin, are the only 2 that cross the blood-retina barrier to form macular pigment in the retina. Lutein also preferentially accumulates in the human brain across multiple life stages. A variety of scientific evidence supports a role for lutein in visual as well as cognitive function across the lifespan. The purpose of this review is to summarize the latest science on lutein's role in the eye and the brain across different ages.

Association between Breastmilk LC PUFA, Carotenoids and Psychomotor Development of Exclusively Breastfed Infants

The first months of infant life are crucial for proper neurodevelopment, which may be influenced by several factors, including nutrition and nutrients (e.g., long-chain polyunsaturated fatty acids (LC PUFA) and carotenoids) of which the concentration in breastmilk is diet-dependent. This study analysed the relationship between the average concentrations of selected LC PUFA and carotenoids in breastmilk samples from the first and third months of lactation and the psychomotor development of exclusively breastfed infants at the sixth month of life. Infant psychomotor development was assessed using the Children Development Scale (DSR). The average age of infants during the assessment was 6.6 ± 0.2 months and 30.9 ± 3.8 years for mothers (n = 39 mother⁻infant pairs). The average concentration of docosahexaenoic acid (DHA) was 0.50% of fatty acids. The average concentration of carotenoids was 33.3 nmol/L for β-carotene, 121 nmol/L for lycopene and 33.3 nmol/L for lutein + zeaxanthin. The total results of the Performance scale and Motor subscale were 39 centiles and 4.1 points, respectively. Adjusted multivariate regression models revealed associations between breastmilk DHA and motor development (β = 0.275; p ≤ 0.05), α-linolenic acid (ALA; β = 0.432; p ≤ 0.05), n-3 LC PUFA (β = 0.423; p ≤ 0.05) and β-carotene (β = 0.359; p ≤ 0.05). In addition, an association between the Perception subscale and DHA was observed (β = 0.316; p ≤ 0.05; model 2). There were no significant associations between the overall Performance scale scores. Due to the positive association between concentrations of n-3 LC PUFA (ALA and DHA) and β-carotene in breastmilk and infant motor development, it is important to provide these nutrients with breastmilk. According to the diet-dependent concentration of these compounds in breastmilk, breastfeeding mothers should have a diet abundant in dietary sources of these nutrients, e.g., fish, nuts, seeds, vegetable oils, vegetables and fruits.

13C-lutein is differentially distributed in tissues of an adult female rhesus macaque following a single oral administration: a pilot study

Despite the growing awareness regarding lutein's putative roles in eyes and brain, its pharmacokinetics and tissue distribution in primates have been poorly understood. We hypothesized that ¹³C-lutein will be differentially distributed into tissues of an adult rhesus macaque (Macaca mulatta) 3 days following a single oral dose. After a year of prefeeding a diet supplemented with unlabeled lutein (1 μmol/kg/d), a 19-year-old female was dosed with 1.92 mg of highly enriched ¹³C-lutein. Tissues of a nondosed, lutein-fed monkey were used as a reference for natural abundance of ¹³C-lutein. On the third day postdose, plasma and multiple tissues were collected. Lutein was quantified by high-performance liquid chromatography-photodiode array detector, and ¹³C-lutein tissue enrichment was determined by liquid chromatography quadrupole time-of-flight mass spectrometry. In the tissues of a reference monkey, ¹²C-lutein with natural abundance of ¹³C-lutein was detectable. In the dosed monkey, highly enriched ¹³C-lutein was observed in all analyzed tissues except for the macular and peripheral retina, with the highest concentrations in the liver followed by the adrenal gland and plasma. ¹³C-lutein accumulated differentially across 6 brain regions. In adipose depots, ¹³C-lutein was observed, with the highest concentrations in the axillary brown adipose tissues. In summary, we evaluated ¹³C-lutein tissue distribution in a nonhuman primate following a single dose of isotopically labeled lutein. These results show that tissue distribution 3 days following a dose of lutein varied substantially dependent on tissue type.

Predicting organ carotenoids levels from analysis of plasma could lead to errors: A study in cynomolgus monkeys

Carotenoids are phytochemicals with strong antioxidant activity against reactive oxygen species that are widely distributed in fruits and vegetables. The beneficial effects of carotenoids on human health have attracted considerable attention. The plasma carotenoid profile in humans is generally recognized to reflect the dietary carotenoid composition. Although carotenoid profile in plasma is believed to correlate well with that in other tissues, the data for tissue accumulation of carotenoids in humans is very limited and poorly understood. In order to test the hypothesis that blood carotenoids reflect tissue accumulation of dietary carotenoids, the cynomolgus monkey was used as a model to determine it's suitable for extrapolation of data on tissue accumulation of carotenoids to humans. Herein, plasma carotenoids were measured in cynomolgus monkeys given a dietary mixture of carotenoids. The findings indicate that cynomolgus monkeys and humans are similar with regard to preferential accumulation of β-cryptoxanthin in the blood and brain. These results suggested that cynomolgus monkeys could be used to collect data on tissue accumulation of carotenoids for extrapolation to humans. The tissue accumulation of carotenoids in other tissues of cynomolgus monkeys that have not yet been evaluated in humans were also investigated, revealing marked differences in carotenoid levels and composition among plasma and various monkey tissues. These results suggest that accumulation of carotenoids in plasma does not reflect necessarily that in tissues, so that predicting the tissue accumulation of carotenoids from plasma carotenoid levels and profiles alone could lead to errors.

The effects of breastfeeding versus formula-feeding on cerebral cortex maturation in infant rhesus macaques

Breastfeeding is positively associated with several outcomes reflecting early brain development and cognitive functioning. Brain neuroimaging studies have shown that exclusively breastfed children have increased white matter and subcortical gray matter volume compared to formula-fed children. However, it is difficult to disentangle the effects of nutrition in breast milk from other confounding factors that affect brain development, particularly in studies of human subjects. Among the nutrients provided by human breast milk are the carotenoid lutein and the natural form of tocopherol, both of which are selectively deposited in brain. Lutein is the predominant carotenoid in breast milk but not in most infant formulas, whereas infant formulas are supplemented with the synthetic form of tocopherol. In this study, a non-human primate model was used to investigate the effects of breastfeeding versus formula-feeding, as well as lutein and natural RRR-α-tocopherol supplementation of infant formula, on brain maturation under controlled experimental conditions. Infant rhesus macaques (Macaca mulatta) were exclusively breastfed, or were fed infant formulas with different levels and sources of lutein and α-tocopherol. Of note, the breastfed group were mother-reared whereas the formula-fed infants were nursery-reared. Brain structural and diffusion MR images were collected, and brain T₂ was measured, at two, four and six months of age. The mother-reared breastfed group was observed to differ from the formula-fed groups by possessing higher diffusion fractional anisotropy (FA) in the corpus callosum, and lower FA in the cerebral cortex at four and six months of age. Cortical regions exhibiting the largest differences include primary motor, premotor, lateral prefrontal, and inferior temporal cortices. No differences were found between the formula groups. Although this study did not identify a nutritional component of breast milk that could be provided to infant formula to facilitate brain maturation consistent with that observed in breastfed animals, our findings indicate that breastfeeding promoted maturation of the corpus callosum and cerebral cortical gray matter in the absence of several confounding factors that affect studies in human infants. However, differences in rearing experience remain as a potential contributor to brain structural differences between breastfed and formula fed infants.

Lutein, zeaxanthin and mammalian development: Metabolism, functions and implications for health

It is now widely accepted that nutrition during critical periods in early development, both pre- and postnatal, may have lifetime consequences in determining health or onset of major diseases in the adult life. Dietary carotenoids have shown beneficial health effects throughout the life cycle due to their potential antioxidant properties, their ability to serves as precursors of vitamin A and to the emerging signaling functions of their metabolites. The non-provitamin A carotenoids lutein and zeaxanthin are emerging as important modulators of infant and child visual and cognitive development, as well as critical effectors in the prevention and treatment of morbidity associated with premature births. This review provides a general overview of lutein and zeaxanthin metabolism in mammalian tissues and highlights the major advancements and remaining gaps in knowledge in regards to their metabolism and health effects during pre- and early post-natal development. Furthering our knowledge in this area of research will impact dietary recommendation and supplementation strategies aimed at sustaining proper fetal and infant growth.

Lutein Is Differentially Deposited across Brain Regions following Formula or Breast Feeding of Infant Rhesus Macaques

Background

Lutein, a yellow xanthophyll, selectively accumulates in primate retina and brain. Lutein may play a critical role in neural and retinal development, but few studies have investigated the impact of dietary source on its bioaccumulation in infants.

Objective

We explored the bioaccumulation of lutein in infant rhesus macaques following breastfeeding or formula-feeding.

Methods

From birth to 6 mo of age, male and female rhesus macaques (Macaca mulatta) were either breastfed (BF) (n = 8), fed a formula supplemented with lutein, zeaxanthin, β-carotene, and lycopene (237, 19.0, 74.2, and 338 nmol/kg, supplemented formula-fed; SF) (n = 8), or fed a formula with low amounts of these carotenoids (38.6, 2.3, 21.5, and 0 nmol/kg, unsupplemented formula-fed; UF) (n = 7). The concentrations of carotenoids in serum and tissues were analyzed by HPLC.

Results

At 6 mo of age, the BF group exhibited significantly higher lutein concentrations in serum, all brain regions, macular and peripheral retina, adipose tissue, liver, and other tissues compared to both formula-fed groups (P < 0.001). Lutein concentrations were higher in the SF group than in the UF group in serum and all tissues, with the exception of macular retina. Lutein was differentially distributed across brain areas, with the highest concentrations in the occipital cortex, regardless of the diet. Zeaxanthin was present in all brain regions but only in the BF infants; it was present in both retinal regions in all groups but was significantly enhanced in BF infants compared to either formula group (P < 0.001). β-Carotene accumulated across brain regions in all groups, but was not detected in retina. Although lycopene was found in many tissues of the SF group, it was not detected in the brain or retina.

Conclusions

Although carotenoid supplementation of infant formula significantly increased serum and tissue lutein concentrations compared to unsupplemented formula, concentrations were still well below those in BF infants. Regardless of diet, occipital cortex showed selectively higher lutein deposition than other brain regions, suggesting lutein's role in visual processing in early life.

Lutein accumulates in subcellular membranes of brain regions in adult rhesus macaques: Relationship to DHA oxidation products

OBJECTIVES

Lutein, a carotenoid with anti-oxidant functions, preferentially accumulates in primate brain and is positively related to cognition in humans. Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (PUFA), is also beneficial for cognition, but is susceptible to oxidation. The present study characterized the membrane distribution of lutein in brain regions important for different domains of cognitive function and determined whether membrane lutein was associated with brain PUFA oxidation.

METHODS

Adult rhesus monkeys were fed a stock diet (~2 mg/day lutein or ~0.5 μmol/kg body weight/day) (n = 9) or the stock diet plus a daily supplement of lutein (~4.5 mg/day or~1 μmol/kg body weight/day) and zeaxanthin (~0.5 mg/day or 0.1 μmol/kg body weight/day) for 6-12 months (n = 4). Nuclear, myelin, mitochondrial, and neuronal plasma membranes were isolated using a Ficoll density gradient from prefrontal cortex (PFC), cerebellum (CER), striatum (ST), and hippocampus (HC). Carotenoids, PUFAs, and PUFA oxidation products were measured using HPLC, GC, and LC-GC/MS, respectively.

RESULTS

All-trans-lutein (ng/mg protein) was detected in all regions and membranes and was highly variable among monkeys. Lutein/zeaxanthin supplementation significantly increased total concentrations of lutein in serum, PFC and CER, as well as lutein in mitochondrial membranes and total DHA concentrations in PFC only (P<0.05). In PFC and ST, mitochondrial lutein was inversely related to DHA oxidation products, but not those from arachidonic acid (P <0.05).

DISCUSSION

This study provides novel data on subcellular lutein accumulation and its relationship to DHA oxidation in primate brain. These findings support the hypothesis that lutein may be associated with antioxidant functions in the brain.

Health Effects of Carotenoids during Pregnancy and Lactation

Adequate nutrition is particularly important during pregnancy since it is needed not only for maintaining the health of the mother, but also determines the course of pregnancy and its outcome, fetus development as well as the child’s health after birth and during the later period of life. Data coming from epidemiological and interventions studies support the observation that carotenoids intake provide positive health effects in adults and the elderly population. These health effects are the result of their antioxidant and anti-inflammatory properties. Recent studies have also demonstrated the significant role of carotenoids during pregnancy and infancy. Some studies indicate a correlation between carotenoid status and lower risk of pregnancy pathologies induced by intensified oxidative stress, but results of these investigations are equivocal. Carotenoids have been well studied in relation to their beneficial role in the prevention of preeclampsia. It is currently hypothesized that carotenoids can play an important role in the prevention of preterm birth and intrauterine growth restriction. Carotenoid status in the newborn depends on the nutritional status of the mother, but little is known about the transfer of carotenoids from the mother to the fetus. Carotenoids are among the few nutrients found in breast milk, in which the levels are determined by the mother’s diet. Nutritional status of the newborn directly depends on its diet. Both mix feeding and artificial feeding may cause depletion of carotenoids since infant formulas contain only trace amounts of these compounds. Carotenoids, particularly lutein and zeaxanthin play a significant role in the development of vision and nervous system (among others, they are important for the development of retina as well as energy metabolism and brain electrical activity). Furthermore, more scientific evidence is emerging on the role of carotenoids in the prevention of disorders affecting preterm infants, who are susceptible to oxidative stress, particularly retinopathy of prematurity.