Absorption and metabolism of xanthophylls

The Role of Diet and Oral Supplementation for the Management of Diabetic Retinopathy and Diabetic Macular Edema: A Narrative Review

Globally, diabetic retinopathy (DR) and diabetic macular edema (DME) are the leading causes of visual loss in working people. Current treatment approaches mostly target proliferative DR and DME, such as intravitreal injections of antivascular endothelial growth factor agents and laser photocoagulation. Before DR progresses into the more severe, sight-threatening proliferative stage, patients with early stages of the disease must get early and appropriate care. It has been suggested that nutraceuticals, which are natural functional foods with minimal adverse effects, may help diabetic patients with DR and DME. Several in vitro and in vivo studies were carried out over the last years, showing the potential benefits of several nutraceuticals in DR due to their neuroprotective, vasoprotective, anti-inflammatory, and antioxidant properties. Although most of the research is restricted to animal models and many nutraceuticals have low bioavailability, these compounds may adjuvate and implement conventional DR therapies. The purpose of this review is (i) to summarize the complex pathophysiology underlying DR and DME and (ii) to examine the main natural-derived molecules and dietary habits that can assist conventional therapies for the clinical management of DR and DME.

Microbiota-derived β carotene is required for strobilation of Aurelia aurita by impacting host retinoic acid signaling

The strobilation process, an asexual reproduction mechanism in Aurelia aurita, transitions from the sessile polyp to the pelagic medusa stage. This study explored the essential role of the microbiome in strobilation, particularly through bacterial beta carotene's impact on the host's retinoic acid signaling pathway. Experiments demonstrated that native polyps undergo normal strobilation while sterile polyps exhibit morphological defects. Supplementing sterile polyps with provitamin A beta carotene or the vitamin A metabolite 9-cis retinoic acid (RA) remedied these defects, underscoring their crucial role in strobilation. Transcriptional analysis revealed that beta carotene and 9-cis RA restored expression of strobilation genes in sterile polyps to native levels. Inhibition of key enzymes in the RA pathway disrupted strobilation, further confirming its importance. The expression of bacterial β-carotenoid synthesis genes in the native microbiome, contrasted with tremendously reduced expression in antibiotic-treated polyps, emphasizes the microbiome's pivotal role in beta carotene provision, facilitating A. aurita's strobilation through RA signaling.

Impact of Paracoccus sp. EGY7 carotenoids on triple-negative breast cancer cells: invitro study

This study investigates the effect of Paracoccus sp. EGY7 carotenoids on the triple-negative breast cancer cell line (MDA-MB-231). The bacterial strain was isolated, and its carotenoids profile was analyzed via HPLC-DAD-MS. Cytotoxicity, migration tests and the expression of BAX and BCL-2 at the gene and protein levels were carried out to evaluate the therapeutic efficiency of the produced carotenoids. Molecular docking analysis estimated the binding affinity between zeaxanthin and BCL-2 protein. Chromatographic analysis revealed zeaxanthin as the major carotenoid (48.3%). The extract exhibited significant cytotoxicity against MDA-MB-231 cells with an IC50 of 1200 µg. It notably reduced cell migration, with wound closure percentages of 37.50% and 79.17% for the 600 µg group, while the percentages were 12.50% and 53.50% for the 1200 µg group, compared to 71.67% and 95.67% for the control at 24 and 48 h post-treatment, respectively. The extract induced apoptosis, as evidenced by significantly increased BAX/BCL-2 gene expression ratios at 600 and 1200 µg (p < 0.05). Western blotting showed increased BAX protein expression at 600 and 1200 µg compared to the control group (p < 0.001), and significantly lower BCL-2 protein expression (p = 0.000005 for 1200 µg and p = 0.0001 for 600 µg). Docking analysis indicated a strong affinity of zeaxanthin to BCL-2 (ΔG = -9.773241 kcal/mol) compared to obatoclax (ΔG = -7.419345 kcal/mol). Paracoccus sp. EGY7 carotenoids are a promising anticancer agent against MDA-MB-231 cells. They effectively promote apoptosis and prevent metastasis, crucial for disease advancement in cancer cells.

Lutein Emulsion Stabilized by a Food-Grade Biopolymer Enhanced Lutein Bioavailability and Improved Retinal Vessel Morphology in Neonatal Rats with Retinopathy of Prematurity

BACKGROUND

Retinopathy of prematurity (ROP) is a leading cause of blindness in infants, affecting 32% of hospitalized preterm infants. Oxidative stress, a primary pathogenic factor in ROP, triggers abnormal neovascularization of retinal vessels. Lutein, an antioxidant and the main component of macular pigment, is found in low levels in preterm infants and may help ameliorate ROP. However, its low bioavailability limits its application as a nutritional intervention.

OBJECTIVES

The study aimed to assess the effect of a lutein emulsion stabilized by a food-grade biopolymer on lutein bioavailability in neonatal rats with ROP and examine the effects of both unemulsified lutein and lutein emulsion on the disease.

METHODS

Neonatal rats were subcutaneously administered KRN 633 (10 mg/kg body weight) on postnatal days 7 and 8 (P7 and P8) to induce ROP. Neonatal rats that did not receive the treatment served as the control. From P9 to P21, both ROP and non-ROP rats were divided into 3 groups and given daily doses of olive oil, unemulsified lutein (2 mg/kg body weight lutein), or lutein emulsion (2 mg/kg body weight lutein). On P22, serum and tissues were collected. Lutein concentrations were measured using ultra-performance liquid chromatography, and retinal morphology was assessed using immunohistochemistry.

RESULTS

Rats treated with lutein emulsion had significantly higher serum and tissue lutein concentrations than those receiving unemulsified lutein. Morphological assessments showed that ROP rats had more tortuous arteries, increased capillary density, enlarged vessels, reduced astrocyte density, and decreased neuronal cells. Both unemulsified lutein and lutein emulsion alleviated these abnormalities, with lutein emulsion showing superior efficacy in restoring neuronal cell levels to normal in the peripheral retina.

CONCLUSIONS

Lutein, in both unemulsified and emulsified forms, effectively inhibited ROP progression in neonatal rats. The biopolymer-based lutein emulsion showed promise as a delivery system to enhance lutein bioavailability and mitigate ROP in preterm infants.

Oral Administration of Lutein Improves Fat Graft Survival by Alleviating Oxidative Stress in Mice

BACKGROUND

Oxidative stress induced by ischemia and hypoxia in fat transplantation is a major obstacle to graft retention. Previous studies have shown that lutein has excellent adipose tissue affinity and antioxidative stress ability, however, the effects of oral lutein on fat transplantation have not yet been studied.

OBJECTIVES

We aimed to investigate whether oral lutein could improve fat transplantation retention by regulating oxidative stress, apoptosis, and inflammatory cytokine levels in graft tissues.

METHODS

Nude mice were assigned to the control group (normal saline), low-dose lutein group (10 mg/kg/day), and high-dose lutein group (20 mg/kg/day) randomly. All mice received treatment by gavage 1 week before fat grafting and continued for 2 weeks. The grafts were collected 1, 2, and 12 weeks after treatment. By conducting histological analyses, Western blotting, quantitative polymerase chain reaction and cell metabolic function detection, the regulatory effects of lutein on apoptosis and oxidative stress in grafts were demonstrated. Additionally, RNA sequencing was conducted to further clarify the efficacy of lutein on fat grafting.

RESULTS

Lutein induced superior graft retention, histological structures, and more viable adipocytes than the control group. It relieved tissue oxidative stress and lipid oxidative damage by decreasing reactive oxygen species and significantly reduced inflammation and apoptosis of grafts. RNA sequencing analysis confirmed that lutein could downregulate the gene expression of oxidative stress and related inflammation and apoptosis.

CONCLUSIONS

Our study suggests that oral administration of lutein can improve fat graft survival by reducing the levels of oxidative stress, inflammation, and apoptosis in grafted fat.

Protection effect of lutein-loaded Pickering emulsion prepared via ultrasound-assisted Maillard reaction conjugates on dry age-related macular degeneration

Age-related macular degeneration (AMD) is a prominent cause of vision loss among the elderly, and the treatment options for dry AMD (dAMD) are severely limited. Lutein has a favorable effect on the treatment of dAMD. Algae oil, rich in docosahexaenoic acid (DHA), is considered an effective intervention for eye diseases. In this study, casein-mannose conjugates were prepared to form algal oil-in-water Pickering emulsions by ultrasound-assisted Maillard reaction. As the ultrasound time increased from 0 to 25 min, the droplet size decreased to 648.2 ± 21.18 nm, which substantially improved the stability of the Pickering emulsions. The retention of lutein in the Pickering emulsions under ultrasonic treatment for 20 min was significantly improved under different conditions. The simulated gastrointestinal digestion revealed that ultrasound-assisted Pickering emulsions are an effective method for improving the bioaccessibility of lutein (19.76%-53.34%). In vivo studies elucidated that the lutein-loaded Pickering emulsions could effectively alleviate retinal thinning induced by sodium iodate (NaIO3) in mice with dAMD. Mechanistically, lutein-loaded Pickering emulsions significantly reduced oxidative stress by decreasing the MDA level, increasing the SOD production, and reducing the retinal ROS production. These findings explored the protective effects of lutein-loaded Pickering emulsions on dAMD and offered promising prospects for the nutritional intervention of dAMD.

Astaxanthin Esters as Functional Food: A Review of Their Nutrition, Phytochemical Structure, Biological Features, and Food Industry Prospects

Astaxanthin (AST), mainly found in algae and shrimp, is a liposoluble ketone carotenoid with a wide range of biological activities and is commonly used in healthcare interventions and cosmetics. AST has a long chain of conjugated double bonds with hydroxyl and ketone groups at both ends, enabling it to form astaxanthin esters (AST-Es) through esterification with fatty acids. The fatty acid structure of AST plays a key role in the stability, antioxidant activity, and bioavailability of AST-Es. Antarctic krill (Euphausia superba) and blood-red algae Haematococcus Pluvialis (H pluvialis)-derived AST-Es exhibit strong antioxidant activity and numerous biological activities, such as improving insulin resistance, preventing Parkinson's disease, regulating intestinal flora, and alleviating inflammatory bowel disease. This review discusses the significance of AST-Es as functional food ingredients, highlighting their nutritional value, phytochemical structure, biological activities, and potential applications in the food industry.

A mechanistic review on growing multiple therapeutic applications of lutein and its global market research

Lutein is a naturally occurring carotenoid synthesized by plants and algae that has a beneficial effect on several biological processes and associated ailments. Its immediate application is in ophthalmology, where it significantly lowers the incidences of age-related macular degeneration (AMD). It also has anti-inflammatory action, treatment of diabetic retinopathy, and cataracts, and enhancement of visual contrast. To critically assess lutein biosynthesis, therapeutic applicability, and market research literature. We have discussed its theoretical frameworks, experimental evidence, limitations, as well as clinical trial results, and future research prospects. The literature for this review article was mined and compiled by collecting and analyzing articles from several databases, including ScienceDirect, Google Scholar, PubMed, Wiley Online Library, Patentscope, and ClinicalTrials.gov published until March 30, 2022. Patent publications were identified using the search terms like IC:(C07C67/56) AND EN_AB:(lutein) OR EN_TI:(lutein) OR EN_AB:(extraction) OR EN_TI:(process). According to the literature, lutein is an essential nutrient given that it cannot be synthesized in the human body and acts as an antioxidant, affecting AMD, diabetic retinopathy, Rheumatic diseases, inflammation, and cancer. Due to inadequate production and laborious extraction, lutein is expensive despite its high demand and applicability. Market research predicts a 6.3% compound annual growth rate for lutein by 2032. Optimizing lutein extraction for high yield and purity is necessary. Lutein has proven applicability in various ailments as well as cosmetics that can be developed as a candidate drug for various diseases discussed in the review.

Preparation of Lutein Nanoparticles by Glycosylation of Saccharides and Casein for Protecting Retinal Pigment Epithelial Cells

Age-related macular degeneration (AMD), a leading cause of visual impairment in the aging population, lacks effective treatment options due to a limited understanding of its pathogenesis. Lutein, with its strong antioxidant properties and ability to mitigate AMD by absorbing ultraviolet (UV) rays, faces challenges related to its stability and bioavailability in functional foods. In this study, we aimed to develop delivery systems using protein-saccharide conjugates to enhance lutein delivery and protect adult retinal pigment epithelial (ARPE-19) cells against sodium iodate (NaIO3)-induced damage. Various saccharides, including mannose, galactose, lactose, maltose, dextran, and maltodextrin, were conjugated to casein via the Maillard reaction for lutein delivery. The resulting lutein-loaded nanoparticles exhibited small size and spherical characteristics and demonstrated improved thermal stability and antioxidant capacity compared to free lutein. Notably, these nanoparticles were found to be nontoxic, as evidenced by reduced levels of cellular reactive oxygen species production (167.50 ± 3.81, 119.57 ± 3.45, 195.15 ± 1.41, 183.96 ± 3.11, 254.21 ± 3.97, 283.56 ± 7.27%) and inhibition of the mitochondrial membrane potential decrease (58.60 ± 0.29, 65.05 ± 2.91, 38.88 ± 1.81, 42.95 ± 1.39, 23.52 ± 1.04, 25.24 ± 0.08%) caused by NaIO3, providing protection against cellular damage and death. Collectively, our findings suggest that lutein-loaded nanoparticles synthesized via the Maillard reaction hold promise for enhanced solubility, oral bioavailability, and biological efficacy in the treatment of AMD.

Advancing nutrition science to meet evolving global health needs

Populations in crisis!A global overview of health challenges and policy efforts within the scope of current nutrition issues, from persistent forms of undernutrition, including micronutrient deficiency, to diet-related chronic diseases. Nutrition science has evolved from a therapeutic and prevention emphasis to include a focus on diets and food systems. Working and consensus definitions are needed, as well as guidance related to healthy diets and the emerging issues that require further research and consensus building. Between nutrient deficiency and chronic disease, nutrition has evolved from focusing exclusively on the extremes of overt nutrient deficiency and chronic disease prevention, to equipping bodies with the ability to cope with physiologic, metabolic, and psychological stress. Just what is 'optimal nutrition', is that a valid public health goal, and what terminology is being provided by the nutrition science community? Nutrition research on 'healthspan', resilience, and intrinsic capacity may provide evidence to support optimal nutrition. Finally, experts provide views on ongoing challenges of achieving consensus or acceptance of the various definitions and interventions for health promotion, and how these can inform government health policies.Nutrition topics that receive particular focus in these proceedings include choline, NAD-replenishment in neurodegenerative diseases, and xanthophyll carotenoids. Choline is a crucial nutrient essential for cellular metabolism, requiring consumption from foods or supplements due to inadequate endogenous synthesis. Maternal choline intake is vital for fetal and infant development to prevent neural tube defects. Neurodegenerative diseases pose a growing health challenge, lacking effective therapies. Nutrition, including NAD-replenishing nutrients, might aid prevention. Emerging research indicates xanthophyll carotenoids enhance vision and cognition, potentially impacting age-related diseases.

Organic Synthesis of New Secosteroids from Fucosterol, Its Intestinal Absorption by Caco-2 Cells, and Simulation of the Biological Activities of Vitamin D

We previously examined the cellular uptake of six types of vitamin D in human intestinal Caco-2 cells. Since vitamins D5-D7 were commercially unavailable, we synthesized these compounds organically before studying them. This process led us to understand that new secosteroids could be generated as vitamin D candidates, depending on the sterol used as the starting material. We obtained two new secosteroids-compounds 3 and 4-from fucosterol in the current study. We investigated the intestinal absorption of these compounds using Caco-2 cells cultured in Transwells and compared the results with vitamin D3, a representative secosteroid. The intestinal absorption of compound 4 was comparable to that of vitamin D3. Compound 3 showed similar uptake levels but transported about half as much as vitamin D3. These compounds demonstrated intestinal absorption at the cellular level. Vitamin D is known for its diverse biological activities manifest after intestinal absorption. Using PASS online simulation, we estimated the biological activity of compound 3's activated form. In several items indicated by PASS, compound 3 exhibited stronger biological activity than vitamins D2-D7 and was also predicted to have unique biological activities.

Carotenoid enrichment in eggs: From biochemistry perspective

The emergence of safe and functional eggs for consumer acceptance has gained focus. The production of carotenoid-enriched eggs has received attention due to its multifunctional biological properties. Nutritional modification of laying hens' diet can be a strategy to produce such eggs. This review presents the chemistry of carotenoids in nature and eggs, the accumulation process of carotenoids into eggs, and the functions of carotenoids in eggs. Our findings showed that carotenoids can be deposited into the egg and contribute to improving its nutritive value. The biosynthesis, chemical structure, and metabolism pathways of carotenoids lead to the deposition of carotenoids into eggs in their original or metabolized forms. Also, some factors modulate the efficiency of carotenoids in fowls before accumulation into eggs. Carotenoid-enriched eggs may be promising, ensuring the availability of highly nutritive eggs. However, further studies are still needed to comprehend the full metabolism process and the extensive functions of carotenoids in eggs.

Neoxanthin is undetectable in human blood after ingestion of fresh young spinach leaf

In a previous study, we demonstrated that the carotenoid neoxanthin was contained in young leafy vegetables including spinach and showed a fat accumulation inhibitory effect in vitro. To evaluate the bioavailability of neoxanthin, a raw young spinach leaf (100 g day-1 for 4 weeks) intake test was performed on 14 participants (36.5 ± 8.0 years; male:female ratio = 9:5). Neoxanthin, neochrome, β-carotene, and lutein concentration in the spinach and blood of participants (before and after the test) was measured using high performance liquid chromatography. Neither neoxanthin nor neochrome was detected in the blood samples, whereas β-carotene and lutein concentration significantly increased (1.4- and 1.9-fold, respectively) during testing. Neoxanthin bioavailability in humans is low; thus, it is unlikely to have a fat accumulation inhibitory effect in vivo, contrary to the result in vitro. Ingesting the leafy vegetables raw can help maintain high neoxanthin levels, but it is not beneficial for neoxanthin bioavailability.

Prevention of aspirin-mediated secondary toxicity by combined treatment of carotenoids in macrophages

Upon understanding the boosting role of carotenoids on the endogenous anti-inflammatory system, it is vital to explore their role in reducing the use of high doses of non-steroidal anti-inflammatory drug (NSAIDs), and their mediated secondary toxicity during the treatment of chronic diseases. The current study investigates the carotenoids potential on inhibition of secondary complications induced by NSAIDs, aspirin (ASA) against lipopolysaccharide (LPS) stimulated inflammation. Initially, this study evaluated a minimal cytotoxic dose of ASA and carotenoids (β-carotene, BC/lutein, LUT/astaxanthin, AST/fucoxanthin FUCO) in Raw 264.7, U937, and peripheral blood mononuclear cells (PBMCs). In all three cells, carotenoids + ASA treatment reduced the LDH release, NO, and PGE2 efficiently than an equivalent dose of carotenoid or ASA treated alone. Based on cytotoxicity and sensitivity results, RAW 264.7 cells were selected for further cell-based assay. Among carotenoids, FUCO + ASA exhibited an efficient reduction of LDH release, NO, and PGE2 than the other carotenoids (BC + ASA, LUT + ASA, and AST + ASA) treatment. FUCO + ASA combination decreased LPS/ASA induced oxidative stress, pro-inflammatory mediators (iNOS, COX-2, and NF-κB), and cytokines (IL-6, TNF-α, and IL-1β) efficiently. Further, apoptosis was inhibited by 69.2% in FUCO + ASA, and 46.7% in ASA than LPS treated cells. A drastic decrease in intracellular ROS generation with the increase in GSH was observed in FUCO + ASA compared to LPS/ASA groups. The results documented on the low dose of ASA with a relative physiological concentration of FUCO suggested greater importance for alleviating secondary complications and optimize prolonged chronic disease treatments with NSAID's associated side effects.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03632-w.

Potential roles of dietary zeaxanthin and lutein in macular health and function

Lutein, zeaxanthin, and meso-zeaxanthin are three xanthophyll carotenoid pigments that selectively concentrate in the center of the retina. Humans cannot synthesize lutein and zeaxanthin, so these compounds must be obtained from the diet or supplements, with meso-zeaxanthin being converted from lutein in the macula. Xanthophylls are major components of macular pigments that protect the retina through the provision of oxidant defense and filtering of blue light. The accumulation of these three xanthophylls in the central macula can be quantified with non-invasive methods, such as macular pigment optical density (MPOD). MPOD serves as a useful tool for assessing risk for, and progression of, age-related macular degeneration, the third leading cause of blindness worldwide. Dietary surveys suggest that the dietary intakes of lutein and zeaxanthin are decreasing. In addition to low dietary intake, pregnancy and lactation may compromise the lutein and zeaxanthin status of both the mother and infant. Lutein is found in modest amounts in some orange- and yellow-colored vegetables, yellow corn products, and in egg yolks, but rich sources of zeaxanthin are not commonly consumed. Goji berries contain the highest known levels of zeaxanthin of any food, and regular intake of these bright red berries may help protect against the development of age-related macular degeneration through an increase in MPOD. The purpose of this review is to summarize the protective function of macular xanthophylls in the eye, speculate on the compounds' role in maternal and infant health, suggest the establishment of recommended dietary values for lutein and zeaxanthin, and introduce goji berries as a rich food source of zeaxanthin.

Effects of dietary fat type and emulsification on carotenoid absorption: a randomized crossover trial

BACKGROUND

Although emerging evidence has suggested that the type and emulsification of dietary fat may be important to carotenoids absorption, these effects have not yet been validated in a human trial.

OBJECTIVE

This study aimed to examine the effects of dietary fat type and emulsification on the bioaccessibility and bioavailability of carotenoids from a carotenoids-rich salad.

METHODS

An identical salad was used for the in vitro and the human trial. This was paired with 28 g of one of the following four different fats: i) non-emulsified olive oil; ii) emulsified olive oil; (iv) non-emulsified coconut oil; v) emulsified coconut oil. The bioaccessibility of total carotenoids (TC) was assessed by a simulated in vitro digestion model. Sixteen subjects consumed salad with four test fats in random order, and plasma triglyceride and carotenoid (lutein, zeaxanthin, α-carotene, β-carotene, and lycopene) concentrations were determined hourly for 10 hours following the consumption. The absorption of TC and individual carotenoids were evaluated by the positive incremental area under the curve (iAUC) of plasma carotenoid concentrations.

RESULTS

The bioaccessibility of TC was greater with olive oil (24.0%) than with coconut oil (14.9%), and with the oil being emulsified (23.5%) rather than non-emulsified (15.4%). Likewise, the positive iAUC_1-10h of TC, α-carotene and lycopene were 55.2%, 110.8% and 45.8%, respectively, higher with olive oil than with coconut oil. Emulsified fat induced 40.0% greater positive iAUC_1-10h of TC than non-emulsified fat.

CONCLUSIONS

The type and emulsification of dietary fat are both essential to the carotenoid absorption. Findings from this study may provide scientific support for designing excipient emulsions as potential dietary strategies to optimize the absorption of fat-soluble compounds.

CLINICAL TRIAL REGISTRY

The present trial was registered at clinicaltrials.gov (NCT04323826), link: https://clinicaltrials.gov/ct2/show/NCT04323826.

The BCO2 Genotype and the Expression of BCO1, BCO2, LRAT, and TTPA Genes in the Adipose Tissue and Brain of Rabbits Fed a Diet with Marigold Flower Extract

This study was undertaken to evaluate the effect of the BCO2 genotype and dietary supplementation with marigold flower extract on the expression of BCO1, BCO2, LRAT, and TTPA genes in the adipose tissue and brain of rabbits. The concentrations of lutein, zeaxanthin, β-carotene, retinol, and α-tocopherol were determined in samples collected from rabbits. Sixty young male Termond White rabbits were allocated to three groups based on their genotype at codon 248 of the BCO2 gene (ins/ins, ins/del, and del/del). Each group comprised two subgroups; one subgroup was administered a standard diet, whereas the diet offered to the other subgroup was supplemented with 6 g/kg of marigold flower extract. The study demonstrated that the BCO2 genotype may influence the expression levels of the BCO2, LRAT, and TTPA genes in adipose tissue, and TTPA and BCO1 genes in the brain. Moreover, an increase in the amount of lutein in the diet of BCO2 del/del rabbits may increase the expression of BCO1, LRAT, and TTPA genes in adipose tissue, and the expression of the BCO2 gene in the brain. Another finding of the study is that the content of carotenoids and α-tocopherol increases in both the adipose tissue and brain of BCO2 del/del rabbits.

The Effect of the BCO2 Genotype on the Expression of Genes Related to Carotenoid, Retinol, and α-Tocopherol Metabolism in Rabbits Fed a Diet with Aztec Marigold Flower Extract

This study investigated the effect of the BCO2 genotype and the addition of Aztec marigold flower extract to rabbit diets on the expression of BCO1, BCO2, LRAT, and TTPA genes in the liver. The levels of lutein, zeaxanthin, β-carotene, retinol, and α-tocopherol in the liver and blood serum of rabbits, as well as plasma biochemical parameters and serum antioxidant enzyme activities were also determined. Sixty male Termond White growing rabbits were divided into three groups based on their genotype at codon 248 of the BCO2 gene (ins/ins, ins/del and del/del); each group was divided into two subgroups: one subgroup received a standard diet, and the other subgroup was fed a diet supplemented with 6 g/kg of marigold flower extract. The obtained results indicate that the BCO2 genotype may affect the expression levels of BCO1 and BCO2 genes in rabbits. Moreover, the addition of marigold extract to the diet of BCO2 del/del rabbits may increase the expression level of the BCO2 gene. Finally, an increase in the amount of lutein in the diet of rabbits with the BCO2 del/del genotype contributes to its increased accumulation in the liver and blood of animals without compromising their health status or liver function.

Effect of Carotenoids on Paraoxonase-1 Activity and Gene Expression

Paraoxonase 1 (PON1) is an antioxidant enzyme attached to HDL with an anti-atherogenic potential. It protects LDL and HDL from lipid peroxidation. The enzyme is sensitive to various modulating factors, such as genetic polymorphisms as well as pharmacological, dietary (including carotenoids), and lifestyle interventions. Carotenoids are nutritional pigments with antioxidant activity. The aim of this review was to gather evidence on their effect on the modulation of PON1 activity and gene expression. Carotenoids administered as naturally occurring nutritional mixtures may present a synergistic beneficial effect on PON1 status. The effect of carotenoids on the enzyme depends on age, ethnicity, gender, diet, and PON1 genetic variation. Carotenoids, especially astaxanthin, β-carotene, and lycopene, increase PON1 activity. This effect may be explained by their ability to quench singlet oxygen and scavenge free radicals. β-carotene and lycopene were additionally shown to upregulate PON1 gene expression. The putative mechanisms of such regulation involve PON1 CpG-rich region methylation, Ca(2+)/calmodulin-dependent kinase II (CaMKKII) pathway induction, and upregulation via steroid regulatory element-binding protein-2 (SREBP-2). More detailed and extensive research on the mechanisms of PON1 modulation by carotenoids may lead to the development of new targeted therapies for cardiovascular diseases.

Identification of Potential Urinary Biomarkers for Bell Pepper Intake by HPLC-HRMS-Based Metabolomics and Structure Elucidation by NMR

Dietary biomarkers show great promise for objectively assessing the food intake in humans. In this study, potential urinary biomarkers for red bell pepper intake were identified based on a dietary intervention study and a comprehensive metabolomics approach. Spot urine samples from 14 volunteers were collected in the two phases of the study (control phase: abstaining from any bell pepper/paprika products; case phase: consumption of a defined amount of fresh red bell pepper and abstaining from any further bell pepper/paprika products) and analyzed by high-performance liquid chromatography high-resolution mass spectrometry (HPLC-HRMS). Comparison of the obtained metabolomics data using statistical analysis revealed that the respective urine metabolomes differ significantly, which was attributable to the bell pepper intake. Some of the most discriminating metabolites were selected and isolated from human urine for unequivocal structure elucidation by nuclear magnetic resonance (NMR) spectroscopy. Herein, seven novel glucuronidated metabolites most likely derived from capsanthin and capsianosides were identified, implying their potential application as dietary biomarkers for the entire Capsicum genus.

Lutein as a Modulator of Oxidative Stress-Mediated Inflammatory Diseases

Lutein is a xanthophyll carotenoid obtained from various foods, such as dark green leafy vegetables and egg yolk. Lutein has antioxidant activity and scavenges reactive oxygen species such as singlet oxygen and lipid peroxy radicals. Oxidative stress activates inflammatory mediators, leading to the development of metabolic and inflammatory diseases. Thus, recent basic and clinical studies have investigated the anti-inflammatory effects of lutein based on its antioxidant activity and modulation of oxidant-sensitive inflammatory signaling pathways. Lutein suppresses activation of nuclear factor-kB and signal transducer and activator of transcription 3, and induction of inflammatory cytokines (interleukin-1β, interleukin-6, monocyte chemoattratant protein-1, tumor necrosis factor-α) and inflammatory enzymes (cyclooxygenase-2, inducible nitric oxide synthase). It also maintains the content of endogenous antioxidant (glutathione) and activates nuclear factor erythroid 2–related factor 2 (Nrf2) and Nrf2 signaling-related antioxidant enzymes (hemeoxygenase-1, NAD(P)H: quinone oxidoreductase 1, glutathione-s-transferase, glutathione peroxidase, superoxide dismutase, catalase). In this review, we have discussed the current knowledge regarding the anti-inflammatory function of lutein against inflammatory diseases in various organs, including neurodegenerative disorders, eye diseases, diabetic retinopathy, osteoporosis, cardiovascular diseases, skin diseases, liver injury, obesity, and colon diseases.

Central Nervous System Migration of Astaxanthin and Adonixanthin Following Their Oral Administration in Cynomolgus Monkeys

Astaxanthin, which has been shown to have significant antioxidant activity, is rapidly spreading as a health functioning ingredient in the health food and cosmetics sectors worldwide. It is well known that astaxanthin acts on the brain; however, there is little evidence of brain translocation due to the difficulty in identifying astaxanthin in tissues. Therefore, in this study, we investigated the concentrations of astaxanthin and adonixanthin, the latter being a biosynthetic intermediate from β-carotene to astaxanthin, in the brain after oral administration in primates. Cynomolgus monkeys were orally administered astaxanthin or adonixanthin at a dose of 50 mg/kg for 10 d, through a disposable catheter inserted into the stomach via the nasal passage. Following euthanization, the monkeys' brains and various other organs were collected. The carotenoid content in serum and individual organs was analyzed by high-performance liquid chromatography. Adonixanthin was found to accumulate at a higher concentration than astaxanthin in monkey brain tissues. Also, both astaxanthin and adonixanthin were found to be distributed in the heart, spleen, liver, and kidneys. These findings indicate that astaxanthin and adonixanthin can enter the central nervous system of primates following their oral administration. This provides important evidence for the activity of astaxanthin and adonixanthin on the central nervous system.

Overflow phenomenon in serum lutein after supplementation: a systematic review supported with SNPs analyses

Lutein, a type of carotenoids, is found to delay the onset and progression of age-related macular degeneration (AMD). Several lutein supplementation studies showed that after an initial increase, lutein serum levels demonstrated a subsequent decrease despite continuous supplementation. In this systematic literature review, this obscure phenomenon was tried to be explained. The subsequent drop in lutein levels was postulated due to down-regulation of lutein receptors scavenger receptor class B type I (SR-BI) in the gastrointestinal tract, upregulation of lutein degrading enzyme β-carotene dioxygenase (BCDO2), or perhaps a combination of both. Some single nucleotides polymorphisms (SNPs) that could have influence on the occurrence of this phenomenon. To date, an exact scientific explanation for this phenomenon has not been established. Further research is needed to investigate this phenomenon in depth to reach an irrefutable explanation, giving that lutein is proven to be effective in delaying the onset and progression of AMD and its metabolism in the human body becomes of equal importance.

Preparation and Characterization of a Lutein Solid Dispersion to Improve Its Solubility and Stability

Lutein has been used as a dietary supplement for the treatment of eye diseases, especially age-related macular degeneration. For oral formulations, we investigated lutein stability in artificial set-ups mimicking different physiological conditions and found that lutein was degraded over time under acidic conditions. To enhance the stability of lutein upon oral intake, we developed enteric-coated lutein solid dispersions (SD) by applying a polymer, hydroxypropyl methylcellulose acetate succinate (HPMCAS-LF), through a solvent-controlled precipitation method. The SD were characterized in crystallinity, morphology, and drug entrapment. In the dissolution profile of lutein SD, a F80 formulation showed resistance toward the acidic environment under simulated gastric conditions while exhibiting a bursting drug release under simulated intestinal conditions. Our results highlight the potential use of HPMCAS-LF as an effective matrix to enhance lutein bioavailability during oral delivery and to provide novel insights into the eye-care supplement industry, with direct benefits for the health of patients.

Uptake of Vitamins D2, D3, D4, D5, D6, and D7 Solubilized in Mixed Micelles by Human Intestinal Cells, Caco-2, an Enhancing Effect of Lysophosphatidylcholine on the Cellular Uptake, and Estimation of Vitamins D' Biological Activities

Vitamins D have various biological activities, as well as intestinal calcium absorption. There has been recent concern about insufficient vitamin D intake. In addition to vitamins D₂ and D₃, there are lesser-known vitamins D₄–D₇. We synthesized vitamins D₅–D₇, which are not commercially available, and then evaluated and compared the mixed micelles-solubilized vitamins D uptake by Caco-2 cells. Except for vitamin D₅, the uptake amounts of vitamins D₄–D₇ by differentiated Caco-2 cells were similar to those of vitamins D₂ and D₃. The facilitative diffusion rate in the ezetimibe inhibited pathway was approximately 20% for each vitamin D type, suggesting that they would pass through the pathway at a similar rate. Lysophosphatidylcholine enhanced each vitamin D uptake by approximately 2.5-fold. Lysophosphatidylcholine showed an enhancing effect on vitamin D uptake by reducing the intercellular barrier formation of Caco-2 cells by reducing cellular cholesterol, suggesting that increasing the uptakes of vitamins D and/or co-ingesting them with lysophosphatidylcholine, would improve vitamin D insufficiency. The various biological activities in the activated form of vitamins D₄–D₇ were estimated by Prediction of Activity Spectra for Substances (PASS) online simulation. These may have some biological activities, supporting the potential as nutritional components.

Xanthophylls from the Sea: Algae as Source of Bioactive Carotenoids

Algae are considered pigment-producing organisms. The function of these compounds in algae is to carry out photosynthesis. They have a great variety of pigments, which can be classified into three large groups: chlorophylls, carotenoids, and phycobilins. Within the carotenoids are xanthophylls. Xanthophylls (fucoxanthin, astaxanthin, lutein, zeaxanthin, and β-cryptoxanthin) are a type of carotenoids with anti-tumor and anti-inflammatory activities, due to their chemical structure rich in double bonds that provides them with antioxidant properties. In this context, xanthophylls can protect other molecules from oxidative stress by turning off singlet oxygen damage through various mechanisms. Based on clinical studies, this review shows the available information concerning the bioactivity and biological effects of the main xanthophylls present in algae. In addition, the algae with the highest production rate of the different compounds of interest were studied. It was observed that fucoxanthin is obtained mainly from the brown seaweeds Laminaria japonica, Undaria pinnatifida, Hizikia fusiformis, Sargassum spp., and Fucus spp. The main sources of astaxanthin are the microalgae Haematococcus pluvialis, Chlorella zofingiensis, and Chlorococcum sp. Lutein and zeaxanthin are mainly found in algal species such as Scenedesmus spp., Chlorella spp., Rhodophyta spp., or Spirulina spp. However, the extraction and purification processes of xanthophylls from algae need to be standardized to facilitate their commercialization. Finally, we assessed factors that determine the bioavailability and bioaccesibility of these molecules. We also suggested techniques that increase xanthophyll’s bioavailability.

Enrichment of chicken table eggs with lycopene and astaxanthin

Ensuring an attractive commercial appearance of egg yolks involves the introduction to the feed of laying hens of the dyes of various origins. Recently, egg producers have preferred natural dyes, which include carotenoids: lycopene and astaxanthin, which can be deposited in chicken egg yolks. The aim of this study was to determine the quality of egg yolks, colour intensity and carotenoid composition of yolks when oil extracts of lycopene (20, 40 and 60 mg/kg feed) or astaxanthin (10, 20 and 30 mg/kg feed) are included in the chickens’ diet. 45 High Line W36 chickens at the age of 24 weeks were used for the experiment. Feeding laying hens with supplements of lycopene oil extracts at doses of 30, 40 and 60 mg/kg and astaxanthin at doses of 10, 20 and 30 mg/kg of feed for 30 days in increasing concentrations did not affect egg weight, albumen height, Haugh unit, strength and the thickness of the shell. The addition of lycopene to the diet of chickens at doses of 20 mg/kg of feed increased the content of lycopene, unidentified carotenoids and the total content of carotenoids in the yolks, but did not change the intensity of their colour. Increasing the dose of lycopene in the diet of chickens to 40 and 60 mg/kg of feed increased the content of lycopene in yolks and the intensity of their colour to 7.4 and 8.0 points against 5.6–6.1 points in the control, but did not affect the content of β-carotene and total carotenoids in the yolks. The addition of astaxanthin oil extract at doses of 10, 20 and 30 mg/kg of feed increased the content of astaxanthin, β-carotene and total carotenoids in chicken egg yolks and increased the intensity of their colour to 12.8, 14.8 and 14.4 points on a 16-point colour scale YolkFanTM. To obtain chicken table eggs with a given colour of the yolks, it is advisable to use the addition of astaxanthin oil extract in doses from 10 to 20 mg/kg of feed for 30 days. The results of the research can be used to develop a technology for the production of functional table eggs enriched with carotenoids of natural origin with an attractive colour for consumers.

Chitosan-sodium alginate-fatty acid nanocarrier system: Lutein bioavailability, absorption pharmacokinetics in diabetic rat and protection of retinal cells against H2O2 induced oxidative stress in vitro

Aiming to enhance therapeutic efficiency of lutein, lutein loaded chitosan-sodium alginate (CS-SA) based nanocarrier system (LNCs) were prepared and evaluated for lutein bioavailability and pharmacokinetics in diabetic rats in comparison to micellar lutein (control). Further, cytotoxicity, cellular uptake and protective activity against H₂O₂ induced oxidative stress in ARPE-19 cells were studied. Results revealed that LNCs displayed maximal lutein AUC in plasma, liver and eye respectively in normal (3.1, 2.7 and 5.2 folds) and diabetic (7.3, 3.4 and 2.8 folds) rats. Lutein from LNCs exhibited a higher half-life time, mean residence time and slow clearance from the plasma, indicating prolonged circulation compared to control. In ARPE-19 cells, pre-treatment with LNCs (10 μM) have significantly attenuated H₂O₂ induced cell death, intracellular ROS and mitochondrial membrane potential compared to control. In conclusion, LNCs improve the lutein bioavailability in conditions like diabetes, diabetic retinopathy and cataract to curtail oxidative stress in retinal cells.

Comparative metabolomics analysis of pigmentary and structural coloration in discus fish (Symphysodon haraldi)

Discus fish have a variety of body colors including pigmentary and structural colors, studies on specific substances and related metabolic pathways associated with body coloration, however, are scarce to the present. Here, we used single-color (blue, yellow and white) of discus for comparative metabolomics analysis of pigmentary and structural coloration. Statistical model showed significant separations between three colors of discus, suggesting the distinct metabolite profiles of discus pigmentary and structural colors. More astaxanthin was found in yellow discus, which might be the cause of yellow pigmentary color. Moreover, docosahexaenoic acid, arachidonic acid, linoleic acid, eicosapentaenoic acid, 1-stearoyl-2-oleoyl-sn-glycerol 3-phosphocholine, dodecanoic acid and myristic acid related to lipid metabolism and pathways of ABC transporters and biosynthesis of unsaturated fatty acids were more enriched in yellow discus. More adenine, xanthine and hypoxanthine were enriched in blue discus, which might account for the blue structural color. Moreover, amino acids associated with purine biosynthesis, e.g., L-alanine and L-isoleucine, were reduced but pathways of protein digestion and absorption, aminoacyl-tRNA biosynthesis, purine metabolism and glycine, serine and threonine metabolism were enriched in blue discus. Overall, these results reveal specific chromophores and related metabolic pathways involved in pigmentary and structural coloration of discus fish. SIGNIFICANCE: We detected specific chromophores present in skin of pigmentary and structural colors of discus and revealed potential metabolic pathways associated with body coloration. These results contribute to our understanding of the mechanism of body color formation in discus fish.

β-Carotene: Preventive Role for Type 2 Diabetes Mellitus and Obesity: A Review

Carotenoids are vital antioxidants for plants and animals. They protect cells from oxidative events and act against the inflammatory process and carcinogenesis. Among the most abundant carotenoids in human and foods is β-carotene. This carotenoid has the highest level of provitamin A activity, as it splits into two molecules of retinol through the actions of the cytosolic enzymes: β-carotene-15,15′-monooxygenase (β-carotene-15,15′-oxygenase 1) and β-carotene-9′,10′-dioxygenase (β-carotene-9′,10′-oxygenase 2). The literature supports the idea that β-carotene acts against type 2 diabetes mellitus, cardiovascular diseases, obesity, and metabolic syndrome. Due to the many processes involved in β-carotene biosynthesis and metabolic function, little is known about such components, since many mechanisms have not yet been fully elucidated. Therefore, our study concisely described the relationships between the consumption of carotenoids, with emphasis on β-carotene, and obesity and type 2 diabetes mellitus and its associated parameters in order to understand the preventive role of carotenoids better and encourage their consumption.

Chili Pepper Carotenoids: Nutraceutical Properties and Mechanisms of Action

Chili pepper is a prominent cultivated horticultural crop that is traditionally used for food seasoning and is applied for the treatment and prevention of multiple diseases. Its beneficial health properties are due to its abundance and variety of bioactive components, such as carotenoids, capsaicinoids, and vitamins. In particular, carotenoids have important nutraceutical properties, and several studies have focused on their potential in the prevention and treatment of human diseases. In this article, we reviewed the state of knowledge of general aspects of chili pepper carotenoids (biosynthesis pathway, types and content in Capsicum spp., and the effects of processing on carotenoid content) and recent findings on the effects of carotenoid nutraceuticals, such as antioxidant, cancer preventive, anti-inflammatory, cardiovascular disorder preventive, and anti-obesity effects.

Biodegradable chitosan-sodium alginate-oleic acid nanocarrier promotes bioavailability and target delivery of lutein in rat model with no toxicity

Efficient delivery of macular carotenoid lutein to target retinal tissue is possible with enhanced intestinal uptake remains a major challenge owing to the polarity, sensitivity to light, heat and solubility. In this study, to overcome such constraints, biodegradable polymers chitosan-sodium alginate-oleic acid based nano-carrier loaded with lutein (LNCs) was prepared and safety efficacy was examined in vivo. Acute-toxicity of LNCs (0.1, 1, 10 and 100 mg/kg body weight) revealed that the LD₅₀ of LNCs was higher than 100 mg/kg body weight. In subacute-toxicity of LNCs (1 and 10 mg/kg body weight) revealed no mortality with no morphological and clinical changes in rats. Histology, haematology and biochemical analysis of urine and plasma confirmed no toxicity of LNCs compared to control. Post-prandial plasma and tissue (retina) levels of lutein from LNCs were higher. Results demonstrate increased bioavailability of lutein from LNCs with no toxicity suggests applications in food and pharma.

Current developments in the nanomediated delivery of photoprotective phytochemicals

Natural products have been used to protect the skin from harmful UV radiation for decades. Due to the ecotoxicological implications of synthetic sunscreen exposure in aquatic ecosystems, there is a greater need to explore alternative sources of UV filters. Recent research has focused on discovering novel UV absorbing photoprotective molecules from nature. In response to the excessive damage caused by UVB rays, plants induce the production of high concentrations of phytoprotective secondary metabolites and anti-oxidative enzymes. Despite promising UV absorbing and photoprotective properties, plant secondary metabolites have been underutilized in topical delivery due to low solubility and high instability. Numerous phytochemicals have been effectively nanosized, incorporated in formulations, and studied for their sustained effects in photoprotection. The present review outlines recent developments in nanosizing and delivering photoprotective crude plant extract and phytochemicals from a phytochemical perspective. We searched for articles using keywords: "UV damage," "skin photoprotection," "photodamage," and "nano delivery" in varied combinations. We identified and reviewed literature from 43 original research articles exploring nanosized phytochemicals and crude plant extracts with photoprotective activity. Nanosized phytochemicals retained higher amounts of bioactive compounds in the skin and acted as depots for their sustained release. Novel approaches in nanosizing considerably improved the photostability, efficacy, and water resistance of plant secondary metabolites. We further discuss the need for broad-spectrum sunscreen products, potential challenges, and future growth in this area.

Novel Insights into the Biotechnological Production of Haematococcus pluvialis-Derived Astaxanthin: Advances and Key Challenges to Allow Its Industrial Use as Novel Food Ingredient

Astaxanthin shows many biological activities. It has acquired a high economic potential and its current market is dominated by its synthetic form. However, due to the increase of the health and environmental concerns from consumers, natural forms are now preferred for human consumption. Haematococcus pluvialis is artificially cultured at an industrial scale to produce astaxanthin used as a dietary supplement. However, due to the high cost of its cultivation and its relatively low biomass and pigment productivities, the astaxanthin extracted from this microalga remains expensive and this has probably the consequence of slowing down its economic development in the lower added-value market such as food ingredient. In this review, we first aim to provide an overview of the chemical and biochemical properties of astaxanthin, as well as of its natural sources. We discuss its bioavailability, metabolism, and biological activities. We present a state-of-the-art of the biology and physiology of H. pluvialis, and highlight novel insights into the biotechnological processes which allow optimizing the biomass and astaxanthin productivities. We are trying to identify some lines of research that would improve the industrial sustainability and economic viability of this bio-production and to broaden the commercial potential of astaxanthin produced from H. pluvialis.

Effect of dispersed form on the bioavailability of β-carotene from daily intake in humans

In a randomized double-blind crossover study, a canned beverage was prepared using an emulsion dispersion formulation (EM) of β-carotene and a crystal dispersion formulation (CR) of β-carotene; the beverages were ingested by human subjects daily for 2 weeks to compare the β-carotene bioavailability. EM-β-carotene enhanced the β-carotene concentrations in human plasma approximately 4-fold, but CR-β-carotene showed no statistically significant enhancement. Bioaccessibility is the ratio of the solubilized fraction to the whole amount ingested. Bioaccessibility of β-carotene from EM-β-carotene was higher than that from CR-β-carotene in an in vitro digestion test. Contrarily, β-carotene from CR-β-carotene, consists of all-trans-β-carotene, was higher than that from EM-β-carotene, consists of a mixture of cis and all-trans-β-carotene, on the uptake by intestinal Caco-2 cells, suggesting that bioaccessibility was a critical factor in β-carotene bioavailability in this study. EM-β-carotene thus has potential as a food coloring agent with value added because it enhances β-carotene bioavailability.

Nutraceutical characteristics of the brown seaweed carotenoid fucoxanthin

Fucoxanthin (Fx), a major carotenoid found in brown seaweed, is known to show a unique and wide variety of biological activities. Upon absorption, Fx is metabolized to fucoxanthinol and amarouciaxanthin, and these metabolites mainly accumulate in visceral white adipose tissue (WAT). As seen in other carotenoids, Fx can quench singlet oxygen and scavenge a wide range of free radicals. The antioxidant activity is related to the neuroprotective, photoprotective, and hepatoprotective effects of Fx. Fx is also reported to show anti-cancer activity through the regulation of several biomolecules and signaling pathways that are involved in either cell cycle arrest, apoptosis, or metastasis suppression. Among the biological activities of Fx, anti-obesity is the most well-studied and most promising effect. This effect is primarily based on the upregulation of thermogenesis by uncoupling protein 1 expression and the increase in the metabolic rate induced by mitochondrial activation. In addition, Fx shows anti-diabetic effects by improving insulin resistance and promoting glucose utilization in skeletal muscle.

Therapeutic Effect of Seaweed Derived Xanthophyl Carotenoid on Obesity Management; Overview of the Last Decade

Present-day lifestyles associated with high calorie-fat intake and accumulation, as well as energy imbalance, have led to the development of obesity and its comorbidities, which have emerged as some of the major health issues globally. To combat the disease, many studies have reported the anti-obesity effects of natural compounds in foods, with some advantages over chemical treatments. Carotenoids, such as xanthophyll derived from seaweeds, have attracted the attention of researchers due to their notable biological activities, which are associated mainly with their antioxidant properties. Their involvement in oxidative stress modulation, the regulation of major transcription factors and enzymes, and their antagonistic effects on various obesity parameters have been examined in both in vitro and in vivo studies. The present review is a collation of published research over the last decade on the antioxidant properties of seaweed xanthophyll carotenoids, with a focus on fucoxanthin and astaxanthin and their mechanisms of action in obesity prevention and treatment.

Effects of Lutein and Astaxanthin Intake on the Improvement of Cognitive Functions among Healthy Adults: A Systematic Review of Randomized Controlled Trials

Background: Fruits and vegetables are generally rich in antioxidants such as carotenoids. Consumption of carotenoids is expected to have benefits on cognitive functions in humans. However, previous randomized controlled trials (RCT) using carotenoids have reported inconsistent results. Therefore, this systematic review (SR) aimed to summarize the effect of carotenoid intake on cognitive functions in humans. Method: PubMed, Cochrane Library, Web of Science, and PsychoINFO were searched for research papers on carotenoid intake with the criteria that 1) oral carotenoid intake was evaluated using RCTs, 2) participants were healthy young, middle-aged, or older, and 3) cognitive functions were measured using RCTs. Results: Five studies using lutein and two studies using astaxanthin met the inclusion criteria. Consumption of lutein and its isomer showed consistent results in selective improvement of visual episodic memory in young and middle-aged adults while inhibition was observed in middle-aged and older adults. One of the two included astaxanthin studies reported a significant improvement of verbal episodic memory performance in middle-aged adults. Conclusion: This SR showed that the 10 mg lutein per day for twelve months can lead to improvement of cognitive functions. Due to the small number of studies, it is difficult to conclude whether astaxanthin would have a positive effect on cognitive functions.

Evaluation of the protein and bioactive compound bioaccessibility/bioavailability and cytotoxicity of the extracts obtained from aquaculture and fisheries by-products

Bioavailability, bioaccessibility, bioactivity and cytotoxicity define if a bioactive compound obtained from aquaculture and associated by-products can be assimilated and used for the body in a safe and efficient way. Four models are used to evaluate the bioavailability: in vitro (simulated gastrointestinal digestion using intestinal epithelial Caco-2 cell cultures); ex vivo (gastrointestinal organs or organoids in laboratory conditions); in situ (intestinal perfusion in animals) and in vivo (animal studies and human studies). In vitro models are very effective, predicting in vivo actions since they evaluate multiple conditions regardless physiological effects. However, in vivo systems are essential for the validation of the results. The use of a combined model between human digestion and cell culture-based models would solve these difficulties, allowing valid conclusions. These studies must be completed with the evaluation of cytotoxicity and oxidative stress markers, providing most accurate results regarding the adverse effect on the body. These methods would test the effect of food structure, food composition, dietary factors and the effect of food processing on bioavailability. Further studies should be carried out to establish a standardized method and achieve a balance between the use of in vivo and in vitro systems.

Randomized controlled trial of a water-soluble formulation of lutein in humans

Lutein is poorly absorbed owing to their high hydrophobicity and crystallinity. This double-blind crossover trial involved eight healthy males who were administrated capsules containing either a lutein water-soluble formulation or a lutein oil suspension for 8 days. In the formulation group, plasma and erythrocytes lutein concentrations and baseline-corrected AUC were two-fold higher than those in the oil suspension group.

Poly (D, L-lactide-co-glycolide)-phospholipid nanocarrier for efficient delivery of macular pigment lutein: absorption pharmacokinetics in mice and antiproliferative effect in Hep G2 cells

Lutein has various biological activities, its application in food and pharma industries are limited due to poor aqueous solubility, stability, and bioavailability. To achieve various benefits, lutein-poly (lactic-co-glycolic acid) (PLGA)-phospholipid (PL) nanocapsules were prepared. Lutein-PLGA NCs (+PL) were synthesized, characterized and its bioavailability was studied in vitro and in vivo. The cellular uptake and anti-proliferative activity were analyzed in Hep G2 cells. The mean size and zeta value of lutein-PLGA NCs (+PL) were 140 ± 6 nm and - 44 mV. The amorphous nature of lutein in PLGA NCs (+PL) was confirmed by XRD and DSC. In vitro lutein release kinetics showed an initial burst followed by sustainable release up to 86%. In vitro bioavailability showed 62.7% higher lutein bioaccessibility than lutein in free form. The AUC of lutein after single oral dose of lutein-PLGA NCs (+PL) revealed 3.91-fold (plasma), 2.89-fold (liver), and 3.12-fold (eyes) higher absorption than the control (mixed micelles). The IC₅₀ of lutein-PLGA NCs (+PL) in Hep G2 cells at 72 h was 4.5 μM as opposed to 23.4 μM for lutein in free form. Thus, results reveal that PL added to PLGA NCs helps in enhancing the solubility which in turn resulted in its better bioavailability and bioefficacy.

Effect of the β-carotene oxygenase 2 genotype on the content of carotenoids, retinol and α-tocopherol in the liver, fat and milk of rabbit does, reproduction parameters and kitten growth

Mutations in the β-carotene oxygenase 2 (BCO2) gene can impair the function of the enzyme that breaks down carotenoids. As a result, gradual accumulation of unoxidized carotenoids in animal tissues gives them a yellow colour. The aim of the study was to determine the content of carotenoids, retinol and α-tocopherol in the liver, fat and milk of rabbit does with three different genotypes determined by AAT-deletion mutation at codon 248 of the BCO2 gene and to find out whether differences in the concentrations of the above compounds in the tissues and milk of the does affect reproduction parameters and the rearing rate of kittens. The experimental materials comprised 36 does, 12 of each genotype of the BCO2 gene, with their litters. Females with their litters were placed in individual cages, on deep litter. Between days 7 and 13 of lactation, samples of milk were collected from the does. The kittens stayed with their mothers until 35 days of age. After weaning, the does were sacrificed. Tissue samples of liver and perirenal fat were collected for chemical analyses. Additionally, based on samples taken from one female, RNA expression levels were determined from the mammary gland and liver, adipose tissue and skin. It was found that homozygous does with deletion at codon 248 of the BCO2 gene were characterized by considerably higher concentrations of xanthophylls and beta-carotene in the liver, adipose tissue and milk than does with the remaining genotypes. However, the differences in the content of the above compounds in milk had no influence on litter weight or the number and rearing rate of kittens. Additionally, RNA expression of the BCO2 gene was found in the mammary tissue of lactating doe and its level was similar to those noted in the liver and adipose tissue.

Bioaccessibility of carotenoids from plant and animal foods

The frequent consumption of carotenoid-rich foods has been associated with numerous health benefits, such as the supply of provitamin A. To exert these health benefits, carotenoids need to be efficiently liberated from the food matrix, micellized in the small intestine, taken up by the enterocytes and absorbed into the human blood stream. Enormous efforts have been made to better understand these processes. Because human studies are costly, labor-intense and time-consuming, the evaluation of carotenoid liberation and micellization at the laboratory scale using simulated in vitro digestion models has proven to be an important tool for obtaining preliminary results prior to conducting human studies. In particular, the liberation from the food matrix and the intestinal micellization can be mimicked by simulated digestion, yielding an estimate of the so-called bioaccessibility of a carotenoid. In the present review, we provide an overview of the carotenoid digestion process in vivo, the currently used in vitro digestion models and the outcomes of previous bioaccessibility studies, with a special focus on correlations with concomitantly conducted human studies. Furthermore, we advocate for the on-going requirement of better standardized digestion protocols and, in addition, we provide suggestions for the complementation of the acquired knowledge and current nutritional recommendations. © 2018 Society of Chemical Industry.

Liquid antisolvent precipitation: an effective method for ocular targeting of lutein esters

Background

Lutein ester (LE) is an important carotenoid fatty acid ester. It is a form in which lutein is present in nature and is produced by free non-esterification and fatty acid esterification. LE is one of the safe sources of lutein. Increasing lutein intake can prevent and treat age-related macular degeneration. In addition, it can effectively inhibit gastric cancer, breast cancer, and esophageal cancer. However, the poor aqueous solubility of LE has impeded its clinical applications.

Objective

The objective of this study was to prepare lutein ester nanoparticles (LE-NPs) by liquid antisolvent precipitation techniques to improve the bioavailability of LE in vivo and improve eye delivery efficiency.

Materials and methods

The physical characterization of LE-NPs was performed, and their in vitro dissolution rate, in vitro antioxidant capacity, in vivo bioavailability, tissue distribution, and ocular pharmacokinetics were studied and evaluated.

Results

The LE freeze-dried powder obtained under the optimal conditions possessed a particle size of ~164.1±4.3 nm. The physical characterization analysis indicated the amorphous form of LE-NPs. In addition, the solubility and dissolution rate of LE-NPs in artificial gastric juice were 12.75 and 9.65 times that of the raw LE, respectively. The bioavailability of LE-NPs increased by 1.41 times compared with that of the raw LE. The antioxidant capacity of LE-NPs was also superior to the raw LE. The concentration of lutein in the main organs of rats treated with the LE-NPs was higher than that in rats treated with the raw LE. The bioavailability of LE-NPs in rat eyeballs was found to be 2.34 times that of the original drug.

Conclusion

LE-NPs have potential application as a new oral pharmaceutical formulation and could be a promising eye-targeted drug delivery system.

Mechanisms of Transport and Delivery of Vitamin A and Carotenoids to the Retinal Pigment Epithelium

Vision depends on the delivery of vitamin A (retinol) to the retina. Retinol in blood is bound to retinol-binding protein (RBP). Retinal pigment epithelia (RPE) cells express the RBP receptor, STRA6, that facilitates uptake of retinol. The retinol is then converted to retinyl esters by the enzyme lecithin:retinol acyltransferase. The esters are the substrate for RPE65, an enzyme that produces 11-cis retinol, which is converted to 11-cis retinaldehyde for transport to the photoreceptors to form rhodopsin. The dietary xanthophylls, lutein (LUT) and zeaxanthin (ZEA), accumulate in the macula of the eye, providing protection against age-related macular degeneration. To reach the macula, carotenoids cross the RPE. In blood, xanthophylls and β-carotene mostly associate with high-density lipoprotein (HDL) and low-density lipoprotein (LDL), respectively. Studies using a human RPE cell model evaluate the kinetics of cell uptake when carotenoids are delivered in LDL or HDL. For LUT and β-carotene, LDL delivery result in the highest rate of uptake. HDL is more effective in delivering ZEA (and meso-ZEA). This selective HDL-mediated uptake of ZEA, via a scavenger receptor and LDL-mediated uptake of LUT and β-carotene provides a mechanism for the selective accumulation of ZEA > LUT and xanthophylls over β-carotene in the macula.