An innovative approach to the determination of safety for a dietary ingredient derived from a new source: case study using a crystalline lutein product

Carotenoid biosynthesis profiling unveils the variance of flower coloration in Tagetes erecta and enhances fruit pigmentation in tomato

Carotenoids play a pivotal role in plant. Tagetes erecta, commonly called marigold, has increasing nutritional and economic value due to its high level of carotenoids in flower. However, the functional genes in the carotenoid biosynthesis of T. erecta have not been studied. In this work, three T. erecta varieties with flowers of yellow, yellow-orange and orange color, respectively, were examined for carotenoids composition and corresponding expression profiling of biosynthetic genes at four developmental stages. The results indicated that the varieties with higher lutein content, orange-flower 'Juwang' and yellow-orange 'Taishan', exhibited significant upregulation of genes in the upstream biosynthesis pathway, especially PDS (phytoene desaturase), PSY (phytoene synthase) and ZDS (zeta-carotene desaturase), whereas downstream carotenoid cleavage genes CCD (carotenoid cleavage dioxygenase) were markedly downregulated throughout flower development in the highest lutein containing variety 'Juwang'. Furthermore, marigold TePDS, TePSYS3 and TeZDS were isolated and transformed into tomato. Overexpression of TePDS or TeZDS resulted in the promotion of fruit ripening and accumulation of carotenoids in the transgenic lines. On the other hand, marigold TePSYS3 showed multiple effects, not only on fruit carotenogenesis but also on pigmentation patterns in vegetative tissues and plant growth. Taken together, the variations in expression profiles of the biosynthetic genes contribute to dynamic change in carotenoid levels and diversity of flower coloration in T. erecta. These functional genes of T. erecta were verified in tomato and provide targets for genetic improvement of fruit carotenoids accumulation.

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.

Lutein-Rich Beverage Alleviates Visual Fatigue in the Hyperglycemia Model of Sprague-Dawley Rats

Asthenopia is a syndrome based on the symptoms of eye discomfort that has become a chronic disease that interferes with and harms people's physical and mental health. Lutein is an internationally recognized "eye nutrient", and studies have shown that it can protect the retina and relieve visual fatigue. In this study, lutein was extracted from marigold (Tagetes erecta L.) and saponified. The purified lutein concentration measured by HPLC was 50.12 mg/100 g. Then, purified lutein was modified to be water-soluble by nanoscale modification and microencapsulation technology. Water-soluble lutein was then mixed with a leaching solution of Chinese wolfberry and chrysanthemum to make a functional beverage. The effects of this beverage on hepatic antioxidant enzymes and the alleviation of visual fatigue in a rat model of diabetes were investigated for 4 weeks. Lutein intake of 0.72 (medium-lutein beverage group) and 1.44 mg/mL (high-lutein beverage group) relieved visual fatigue, ameliorated turbidity symptoms of impaired crystalline lenses, reduced hepatic MDA concentration, increased hepatic GSH concentration, and significantly increased the activities of the hepatic antioxidant enzymes SOD, CAT, GSH-Px, and GR in rats. These data suggest that a lutein-rich beverage is an effective and harmless way to increase the total anti-oxidation capacity of lenses and alleviate visual fatigue.

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.

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.

Strobilanthes crispus bioactive subfraction inhibits tumor progression and improves hematological and morphological parameters in mouse mammary carcinoma model

ETHNOPHARMACOLOGICAL RELEVANCE

Locally known as 'pecah batu', 'bayam karang', 'keci beling' or 'batu jin', the Malaysian medicinal herb, Strobilanthes crispus (S. crispus), is traditionally used by the local communities as alternative or adjuvant remedy for cancer and other ailments and to boost the immune system. S. crispus has demonstrated multiple anticancer therapeutic potential in vitro and in vivo. A pharmacologically active fraction of S. crispus has been identified and termed as F3. Major constituents profiled in F3 include lutein and β-sitosterol.

AIM OF THE STUDY

In this study, the effects of F3, lutein and β-sitosterol on tumor development and metastasis were investigated in 4T1-induced mouse mammary carcinoma model.

MATERIALS AND METHODS

Tumor-bearing mice were fed with F3 (100 mg/kg/day), lutein (50 mg/kg/day) and β-sitosterol (50 mg/kg/day) for 30 days (n = 5 each group). Tumor physical growth parameters, animal body weight and development of secondary tumors were investigated. The safety profile of F3 was assessed using hematological and histomorphological changes on the major organs in normal control mice (NM).

RESULTS

Our findings revealed significant reduction of physical tumor growth parameters in all tumor-bearing mice treated with F3 (TM-F3), lutein (TM-L) or β-sitosterol (TM-β) as compared with the untreated group (TM). Statistically significant reduction in body weight was observed in TM compared to the NM or treated (TM-F3, TM-L and TM-β) groups. Histomorphological examination of tissue sections from the F3-treated group showed normal features of the vital organs (i.e., liver, kidneys, lungs and spleen) which were similar to those of NM. Administration of F3 to NM mice (NM-F3) did not cause significant changes in full blood count values.

CONCLUSION

F3 significantly reduced the total tumor burden and prevented secondary tumor development in metastatic breast cancer without significant toxicities in 4T1-induced mouse mammary carcinoma model. The current study provides further support for therapeutic development of F3 with further pharmacokinetics studies.

Antioxidant supplements in age-related macular degeneration: are they actually beneficial?

Age-related macular degeneration (ARMD) is one of the prominent causes of central visual loss in the older age group in the urbanized, industrialized world. In recent years, many epidemiological studies and clinical trials have evaluated the role of antioxidants and micronutrients to prevent the progression of ARMD. In this article, we review some of these major studies. In addition, we review the absorption and bioavailability and possible undesirable effects of these nutrients after ingestion. The role of genotypes and inappropriate use of these supplements are also discussed. From all the above evidence, we conclude that it may not be prudent to prescribe these formulations without a proper assessment of the individual's health and dietary status. The effectiveness of all the components in antioxidant formulations is controversial. Thus, these supplements should not be prescribed just for the purpose of providing patients some kind of therapy, which may give a false sense of mental satisfaction.

Lutein Supplementation for Eye Diseases

Lutein is one of the few xanthophyll carotenoids that is found in high concentration in the macula of human retina. As de novo synthesis of lutein within the human body is impossible, lutein can only be obtained from diet. It is a natural substance abundant in egg yolk and dark green leafy vegetables. Many basic and clinical studies have reported lutein's anti-oxidative and anti-inflammatory properties in the eye, suggesting its beneficial effects on protection and alleviation of ocular diseases such as age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, myopia, and cataract. Most importantly, lutein is categorized as Generally Regarded as Safe (GRAS), posing minimal side-effects upon long term consumption. In this review, we will discuss the chemical structure and properties of lutein as well as its application and safety as a nutritional supplement. Finally, the effects of lutein consumption on the aforementioned eye diseases will be reviewed.

Nutrients for Prevention of Macular Degeneration and Eye-Related Diseases

The risk of macular degeneration can be reduced through the consumption of antioxidant-rich foods, supplements, and nutraceutical formulas. This review focuses on the antioxidants, vitamins, and minerals that have been reported for reducing the risk of macular degeneration and other eye-related diseases. Antioxidants including anthocyanins, carotenoids, flavonoids, and vitamins have been shown to reduce the risk of eye-related diseases. Anthocyanins extracted from berries are powerful antioxidants. Cyanidin, delphinidin, malvidin, pelargonidin, peonidin, and petunidin are anthocyanin aglycones detected in berries, currants, and other colored fruits and vegetables. β-Carotene, as well as xanthophyll lutein and zeaxanthin, have been reported to reduce the risk of macular degeneration. Flavonoids from plants help in the prevention of eye-related diseases through anti-inflammatory mechanisms. A combination of these antioxidants, vitamins, and minerals possess a synergistic effect on the prevention or risk reduction of macular degeneration. Formulas have been developed as dietary supplements to cater to the high demand from consumers and patients with eye problems. Many of the formulated dietary supplements that are sold in the market have been clinically proven for their efficacy to treat eye diseases. Although the bioactivities in the supplement capsules or tablets have been scientifically established for reducing risks of several diseases, which include macular degeneration and other eye-related diseases, knowledge on the right dosage, efficacy, and bioavailability of antioxidants, vitamins, and minerals is important for consumers. The information may help them make the best decision in choosing the right dietary supplements and nutraceuticals following the evidence-based recommended dosages and reference intakes for improving general health and preventing eye-related diseases. This review covers the potential causal factors involved in eye diseases, clinically proven treatments, and controversial findings on the antioxidants in the prevention of macular degeneration. Future studies should consider multiethnic and multicenter trials for eliminating potential bias in research.

Lutein, zeaxanthin, and meso-zeaxanthin: The basic and clinical science underlying carotenoid-based nutritional interventions against ocular disease

The human macula uniquely concentrates three carotenoids: lutein, zeaxanthin, and meso-zeaxanthin. Lutein and zeaxanthin must be obtained from dietary sources such as green leafy vegetables and orange and yellow fruits and vegetables, while meso-zeaxanthin is rarely found in diet and is believed to be formed at the macula by metabolic transformations of ingested carotenoids. Epidemiological studies and large-scale clinical trials such as AREDS2 have brought attention to the potential ocular health and functional benefits of these three xanthophyll carotenoids consumed through the diet or supplements, but the basic science and clinical research underlying recommendations for nutritional interventions against age-related macular degeneration and other eye diseases are underappreciated by clinicians and vision researchers alike. In this review article, we first examine the chemistry, biochemistry, biophysics, and physiology of these yellow pigments that are specifically concentrated in the macula lutea through the means of high-affinity binding proteins and specialized transport and metabolic proteins where they play important roles as short-wavelength (blue) light-absorbers and localized, efficient antioxidants in a region at high risk for light-induced oxidative stress. Next, we turn to clinical evidence supporting functional benefits of these carotenoids in normal eyes and for their potential protective actions against ocular disease from infancy to old age.

An Evidence-Based Systematic Review of Lutein by the Natural Standard Research Collaboration

An evidence-based systematic review of lutein by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Lutein supplementation increases breast milk and plasma lutein concentrations in lactating women and infant plasma concentrations but does not affect other carotenoids

Lutein is a carotenoid that varies in breast milk depending on maternal intake. Data are lacking with regard to the effect of dietary lutein supplementation on breast milk lutein concentration during lactation and subsequent plasma lutein concentration in breast-fed infants. This study was conducted to determine the impact of lutein supplementation in the breast milk and plasma of lactating women and in the plasma of breast-fed infants 2-3 mo postpartum. Lutein is the dominant carotenoid in the infant brain and the major carotenoid found in the retina of the eye. Eighty-nine lactating women 4-6 wk postpartum were randomly assigned to be administered either 0 mg/d of lutein (placebo), 6 mg/d of lutein (low-dose), or 12 mg/d of lutein (high-dose). The supplements were consumed for 6 wk while mothers followed their usual diets. Breast milk carotenoids were measured weekly by HPLC, and maternal plasma carotenoid concentrations were measured at the beginning and end of the study. Infant plasma carotenoid concentrations were assessed at the end of the study. No significant differences were found between dietary lutein + zeaxanthin intake and carotenoid concentrations in breast milk and plasma or body mass index at baseline. Total lutein + zeaxanthin concentrations were greater in the low- and high-dose-supplemented groups than in the placebo group in breast milk (140% and 250%, respectively; P < 0.0001), maternal plasma (170% and 250%, respectively; P < 0.0001), and infant plasma (180% and 330%, respectively; P < 0.05). Lutein supplementation did not affect other carotenoids in lactating women or their infants. Lactating women are highly responsive to lutein supplementation, which affects plasma lutein concentrations in the infant. This trial was registered at clinicaltrials.gov as NCT01747668.

Effect of carotenoid lutein on N-nitrosodiethylamine-induced hepatocellular carcinoma and its mechanism of action

Oxycarotenoid lutein (3,3'-dihydroxy-β,ε-carotene) was checked for anticarcinogenic activity against N-nitrosodiethylamine-induced hepatocellular carcinoma (HCC) in rats. Lutein could significantly reduce the altered morphological and pathological changes in the liver induced by N-nitrosodiethylamine. Biochemical analysis of serum and tissues indicated that alanine transaminase, aspartate transaminase, and alkaline phosphatase were significantly elevated in the control group and significantly reduced in the lutein-treated groups. These enzymes in liver tissue, which were found to be elevated in the control group, were significantly reduced in the lutein-treated groups. Glutathione level was low in the control groups and it was found to be increased in the treated groups. The activity of γ-glutamyl transpeptidase, a marker of cellular proliferation, was found to be significantly elevated in both the serum and the liver in the control group, which was reduced by the administration of lutein. Studies on the mechanism of action of lutein have indicated that it could significantly inhibit cytochrome P450 enzymes in vitro and in vivo in rats. Moreover, lutein could enhance the detoxifying enzymes glutathione-S-transferase and UDP glucuronyl transferase in vivo. Inhibition of carcinogenesis by lutein could be because of a combined effect of its antioxidant activity along with the inhibition of cytochrome P450 enzymes and inducing detoxifying enzymes. Lutein is nontoxic and is one of the prime compounds in the chemoprevention trials of the future.

Acute and subacute toxicity assessment of lutein in lutein-deficient mice

Dietary lutein consumption is lower than the actual recommended allowances to prevent macular degeneration; thus dietary lutein supplements have been recommended. This study aimed to investigate potential adverse effect of lutein from Tagetes erecta in lutein-deficient (LD) male mice. Preliminary acute toxicity study revealed that the LD50 exceeded the highest dose of 10000 mg/kg BW. In a subacute study, male mice were gavaged with 0, 100, 1000 mg/kg BW/day for a period of 4 wk. Plasma lutein levels increased dose dependently (P < 0.01) after acute and subacute feeding of lutein in LD mice. Compared to the control (peanut oil without lutein) group, no treatment-related toxicologically significant effects of lutein were prominent in clinical observation, ophthalmic examinations, body, and organ weights. Further, no toxicologically significant findings were eminent in hematological, histopathological, and other clinical chemistry parameters. In the oral subacute toxicity study, the no-observed-adverse-effect level (NOAEL) for lutein in LD mice was determined as 1000 mg/kg/day, the highest dose tested.

Studies on meso-zeaxanthin for potential toxicity and mutagenicity

The purpose of these studies was to examine the potential toxicity and genotoxicity of meso-zeaxanthin (MZ). Toxicity was assessed by administering MZ daily to rats for 13 weeks followed by a 4-week recovery period. Potential genotoxicity was assessed in separate experiments using the Ames test method. Rats were randomly assigned to four groups to receive corn oil (control) or MZ at dose levels of 2, 20 and 200 mg/kg/day by oral gavage (10/sex/group). Additional rats (five of each sex) in the control and the 200 mg/kg/day groups were retained for the recovery period. No compound-related clinical, biochemical or pathological signs or symptoms were noted and the no-observed-adverse-effect-level (NOAEL) of MZ was >200 mg/kg/day. To investigate genotoxicity, MZ was tested for its ability to induce reverse mutations (±microsomal enzymes) at 2 genomic loci; the histidine locus of 4 strains of Salmonella typhimurium and the tryptophan locus of Escherichia coli strain WP2uvrA. Six doses of MZ ranging from 10 to 5000 μg/plate were tested twice with vehicle and positive controls using 3 plates/dose. MZ did not cause any increase in the mean number of revertants/plate with any bacterial strain, with or without microsomal enzymes, and was therefore unlikely to be mutagenic.

Carotenoid lutein: a promising candidate for pharmaceutical and nutraceutical applications

Carotenoids play a major role in scavenging singlet oxygen and peroxyl radicals in human. Several studies have shown that lutein and zeaxanthin help to protect the skin and eyes from photodamage and offer several other health benefits. The potential benefits of using lutein as nutritional or cosmetic ingredient are reviewed in this paper. Recent advances in health and cosmetic care provided by lutein are also discussed. This review also mentions various drug carrier systems that have been studied for the delivery of lutein.

Dietary carotenoid lutein protects against DNA damage and alterations of the redox status induced by cisplatin in human derived HepG2 cells

Several epidemiological and experimental studies has been reported that lutein (LT) presents antioxidant properties. Aim of the present study was to investigate the protective effects of LT against oxidative stress and DNA damage induced by cisplatin (cDDP) in a human derived liver cell line (HepG2). Cell viability and DNA-damage was monitored by MTT and comet assays. Moreover, different biochemical parameters related to redox status (glutathione, cytochrome-c and intracellular ROS) were also evaluated. A clear DNA-damage was seen with cDDP (1.0μM) treatment. In combination with the carotenoid, reduction of DNA damage was observed after pre- and simultaneous treatment of the cells, but not when the carotenoid was added to the cells after the exposure to cDDP. Exposure of the cells to cDDP also caused significant changes of all biochemical parameters and in co-treatment of the cells with LT, the carotenoid reverted these alterations. The results indicate that cDDP induces pronounced oxidative stress in HepG2 cells that is related to DNA damage and that the supplementation with the antioxidant LT may protect these adverse effects caused by the exposure of the cells to platinum compound, which can be a good predict for chemoprevention.

Carotenoid lutein protects rats from paracetamol-, carbon tetrachloride- and ethanol-induced hepatic damage

OBJECTIVES

Carotenoids are a class of natural fat-soluble pigments that are found in many fruits and vegetables. Consumption of a diet rich in carotenoids has been epidemiologically correlated with a lower risk for several diseases. In the present study the carotenoid lutein (3,3'-dihydroxy-beta,epsilon-carotene) was evaluated for its hepatoprotective activity in rats.

METHODS

Paracetamol, 20% ethanol and carbon tetrachloride were used to induce liver toxicity.

KEY FINDINGS

Levels of serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase and alkaline phosphatases, which were increased in the serum, were found to be significantly reduced by the treatment of lutein in a dose-dependent manner, indicating that lutein may reduce the hepatotoxicity induced by these agents(. )Serum bilirubin was also significantly lower in lutein-treated groups compared with control. Increased lipid peroxidation, conjugated diene and hydroperoxides in the liver tissue produced by the administration of paracetamol were found to be reduced in the lutein-treated groups. Levels of antioxidant enzymes, like superoxide dismutase, catalase, glutathione peroxidase and glutathione, were found to be increased in lutein-treated groups compared with control group during alcohol- and CCl(4)-induced liver toxicity. Hydroxyproline, which is an indicator of fibrosis in liver tissue, was high in the ethanol-treated control group. Hydroxyproline levels were decreased by simultaneous lutein administration.

CONCLUSIONS

Histopathological evidence confirmed the protection offered by lutein from the tissue damage caused by hepatotoxins. The hepatoprotective action may be due to lutein's ability to scavenge reactive oxygen radicals.

Lutein protects RGC-5 cells against hypoxia and oxidative stress

Retinal ischemia and oxidative stress lead to neuronal death in many ocular pathologies. Recently, we found that lutein, an oxy-carotenoid, protected the inner retina from ischemia/reperfusion injury. However, it is uncertain whether lutein directly protects retinal ganglion cells (RGCs). Here, an in vitro model of hypoxia and oxidative stress was used to further investigate the neuroprotective role of lutein in RGCs. Cobalt chloride (CoCl₂) and hydrogen peroxide (H₂O₂) were added to a transformed RGC cell line, RGC-5, to induce chemical hypoxia and oxidative stress, respectively. Either lutein or vehicle was added to cultured cells. A higher cell count was observed in the lutein-treated cells compared with the vehicle-treated cells. Our data from this in vitro model revealed that lutein might protect RGC-5 cells from damage when exposed to either CoCl₂-induced chemical hypoxia or H₂O₂-induced oxidative stress. These results suggest that lutein may play a role as a neuroprotectant.

Effects of lutein and zeaxanthin on aspects of eye health

Lutein and zeaxanthin are members of the oxygenated carotenoids found particularly in egg yolks and dark-green leafy vegetables. A great deal of research has focused on their beneficial roles in eye health. The present article summarises the current literature related to the bioactivity of these carotenoids, emphasising their effects and possible mechanisms of action in relation to human eye health. Available evidence demonstrates that lutein and zeaxanthin are widely distributed in a number of body tissues and are uniquely concentrated in the retina and lens, indicating that each has a possible specific function in these two vital ocular tissues. Most of epidemiological studies and clinical trials support the notion that lutein and zeaxanthin have a potential role in the prevention and treatment of certain eye diseases such as age-related macular degeneration, cataract and retinitis pigmentosa. The biological mechanisms for the protective effects of these carotenoids may include powerful blue-light filtering activities and antioxidant properties. Although most studies point towards significant health benefits from lutein and zeaxanthin, further large-scale randomised supplementation trials are needed to define their effects on ocular function in health and disease.

Lutein from ozone-treated corn retains antimutagenic properties

The present study was conducted to determine the influence of an ozonation process on lutein and protein in clean and contaminated corns. This study aimed to determine the levels of lutein and protein in corn before and after ozonation and to verify the antimutagenic potential of the extracted lutein against aflatoxin using the Ames test. The lutein content was analyzed by high-performance liquid chromatography. Nitrogen analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used to analyze protein. Clean ozone-treated corn had a total lutein content of 28.36 microg/g, which was higher than that of 22.75 microg/g in the untreated clean corn. However, the lutein content was 11.69 microg/g in the ozone-treated contaminated corn, which was lower than that of 16.42 microg/g in the untreated contaminated corn. In both corn samples, the protein content of ozone-treated corn was lower than that of untreated corn, indicating that protein could be destroyed by the ozonation process, which may influence the nutritious value of the corn. Lutein extracts alone showed no mutagenic potential against Salmonella typhimurium tester strains TA100. Lutein extracts from corn inhibited the mutagenicity of AFB1 in a dose-response manner more efficiently than lutein standard. Lutein extracts from different corn samples had similar antimutagenic potentials against AFB1, so the ozone treatment did not affect the antimutagenic potentials of lutein extracts.

Toxicity profile of lutein and lutein ester isolated from marigold flowers (Tagetes erecta)

Lutein is a carotenoid with antioxidant properties and is commonly present in many fruits, vegetables, and egg yolk. Lutein affords protection against the development of the two common eye diseases of aging: cataract and macular degeneration. As the dietary lutein concentration is much lower compared to the actual requirement to reduce macular degeneration, supplementation of lutein is under consideration. There are very few data on the toxicity of lutein. In the present study, the authors have evaluated the short-term and long-term toxicity profile of lutein and its esterified form isolated from marigold flowers (Tagetes erecta) in young adult male and female Wistar rats. Lutein and its ester form administered orally at doses of 4, 40, and 400 mg/kg body weight for 4 weeks for short-term toxicity study and 13 weeks for a subchronic toxicity study did not produced any mortality, change in body weight, food consumption pattern, organ weight, and other adverse side reactions. Administration of lutein and ester form did not alter the hepatic and renal function, and did not produce any change in the hematological parameters and in lipid profile. Histopathological analysis of the organs supported the nontoxicity of lutein and its ester form.

Lutein presents suppressing but not blocking chemopreventive activity during diethylnitrosamine-induced hepatocarcinogenesis and this involves inhibition of DNA damage

Cancer chemopreventive agents are classified as blocking or suppressing agents if they inhibit initiation or promotion/progression phase of carcinogenesis, respectively. Two experiments were conducted in order to classify lutein as a blocking and/or suppressing agent during rat hepatocarcinogenesis. Inhibitory effects of lutein on hepatic preneoplastic lesions (PNL) and DNA strand breakage induced in Wistar rats by the resistant hepatocyte model of hepatocarcinogenesis (initiation with diethylnitrosamine and promotion with 2-acetylaminofluorene coupled with partial hepatectomy) were investigated when the carotenoid was administered specifically during initiation (experiment 1) or promotion (experiment 2) phase. Animals received by gavage during 2 (experiment 1) or six (experiment 2) consecutive weeks on alternate days 70 mg/kg body weight of lutein. Rats treated with only corn oil during these same periods and submitted to this model were used as controls. Treatment with lutein during initiation did not inhibit nor induced (P>0.05) hepatic preneoplastic lesions and DNA damage. On the other hand, treatment during promotion inhibited (P<0.05) the size of hepatic macroscopic nodules and DNA damage and increased (P<0.05) lutein hepatic levels that reached levels seen in human liver samples. Lutein presented inhibitory actions during promotion but not initiation of hepatocarcinogenesis, being classified as a suppressing agent. This reinforces lutein as a potential agent for liver cancer chemoprevention.

Antioxidant activity, mutagenicity/anti-mutagenicity, and clastogenicity/anti-clastogenicity of lutein from marigold flowers

High dietary intake of lutein has been associated with risk reduction of many chronic diseases, including age-related macular degeneration (AMD), cancer, and cardiovascular diseases. Lutein in food is generally regarded as safe. However, information on the toxicological and beneficial effect of lutein at higher doses is limited. In this study, large amount of lutein was extracted and purified from marigold flower (Tagetes erecta L.). The antioxidant activity of lutein was examined by using the photochemiluminescence (PCL) assay and the beta-carotene-linoleic acid model system (beta-CLAMS). Lutein showed a greater antioxidant activity than the other two common carotenoids, beta-carotene and lycopene. The mutagenicity and anti-mutagenicity of lutein at 334, 668 and 1335 microg/plate were examined using the standard Ames test in the presence and absence of S9 mix. Lutein was not only found to be non-mutagenic at all doses, but it showed an anti-mutagenic effect in a dose-dependent manner. Similar results were found in a chromosome aberration test using Chinese hamster ovary cells for the evaluation of clastogenicity and anti-clastogenicity of lutein at 66.8, 133.5 and 267.0 mg/L. Our findings provided scientific evidence for the safe use and health beneficial effects of lutein.

Risk assessment for the carotenoids lutein and lycopene

Lutein and lycopene, two prevalent carotenoids in the human diet have become increasingly popular ingredients in dietary supplements. A large body of human and animal research suggests that oral forms of these carotenoids may provide benefits in the areas of eye, prostate, skin and cardiovascular health. The increased awareness and use of these ingredients in dietary supplements warrants a comprehensive review of their safety. Systematic evaluation of the research designs and data provide a basis for risk assessment and the usual tolerable Upper Level of Intake (UL) derived from it if the newer methods described as the Observed Safe Level (OSL) or Highest Observed Intake (HOI) are utilized. The OSL risk assessment method indicates that the evidence of safety is strong at intakes up to 20mg/d for lutein, and 75 mg/d for lycopene, and these levels are identified as the respective OSL. Although much higher levels have been tested without adverse effects and may be safe, the data for intakes above these levels are not sufficient for a confident conclusion of long-term safety.

Protective Effect of Lutein on Ischemia-Reperfusion Injury in Rat Small Intestine

Lutein is a carotenoid and it has antioxidant effects. Lutein may have a protective effect on ischemia reperfusion (I/R) injury induced by free radical species. However, little is known about the protective effect of lutein on I/R injury in vivo. The present study was undertaken to clarify the protective effects of lutein on I/R injuries in the rat small intestine. Administration of lutein before intestinal I/R attenuated the damage to villi and deciduation of enterocytes and suppressed the increase in lipid peroxide.

Lutein: A Valuable Ingredient of Fruit and Vegetables

Lutein is a human serum carotenoid which is not synthesized by humans and thus must be obtained by the ingestion of food containing it such as fruits and vegetables. Lutein is present in different forms in those foods as all-trans-lutein, cis-lutein, epoxi-lutein, and lutein linked to proteins. It discusses if the intake of lutein or diets supplemented with lutein or diets rich in fruits and vegetables are important in the prevention of diseases like some cancers, cardiovascular diseases, etc., that may be affected by the antioxidant effect of lutein; or in the prevention of age-related macular degeneration and other eye diseases. The concentration of lutein in fruits and vegetables depends on the species. We've included the concentration of lutein in 74 species reported by different authors since 1990. Currently the quantification of lutein is mainly performed by HPLC, but more investigations into a quantification method for lutein, lutein isomers, and epoxi-lutein are necessary. Improvement of lutein extraction methods is important as well. Methods commonly used in the vegetable and fruit industry like heat treatment, storage conditions, etc. can change lutein concentrations; other factors depend on the plant, for instance the variety, the stage of maturity, etc.

Some dietary and adipose tissue carotenoids are associated with the risk of nonfatal acute myocardial infarction in Costa Rica

Antioxidants, particularly carotenoids and tocopherols, may protect against cardiovascular disease. The objective of this study was to determine whether dietary and adipose tissue carotenoids and tocopherols are associated with the risk of myocardial infarction (MI). Cases (n = 1456) of a first acute MI were identified and matched by age, sex, and residence to randomly selected population controls (n = 1456) living in Costa Rica. Carotenoids and tocopherols were measured in adipose tissue using HPLC. Dietary intake was assessed using a validated FFQ. Anthropometrical and lifestyle data were collected using an interviewer-administered questionnaire. Subjects were distributed into quintiles of intake or adipose tissue concentration of carotenoids or tocopherols. The lowest quintile was used as the referent in conditional logistic regression analyses. Adipose tissue beta-carotene showed a significant inverse relation with MI risk; the odds ratio (OR) comparing the highest to the lowest quintile was 0.70 (95% CI: 0.51-0.96, P for trend = 0.02). Intake of fruits and vegetables that are rich in beta-carotene was also inversely associated with the risk of MI (OR = 0.74; CI: 0.54-1.01, P for trend = 0.09). In contrast, lutein + zeaxanthin in adipose tissue (OR = 1.46; CI: 1.05-2.05, P for trend = 0.02) and diet (OR = 1.18; CI: 0.88-1.57, P for trend = 0.02) was positively associated with MI risk. MI risk was not associated with any of the other carotenoids or tocopherols in the diet or adipose tissue. Thus, the inverse association between beta-carotene and MI risk suggests that beta-carotene protects against MI or it is a marker of some protective factor in foods containing beta-carotene. The mechanism underlying the positive association between lutein + zeaxanthin and the risk of MI warrants investigation.

The science behind lutein

In humans, as in plants, the xanthophyll lutein is believed to function in two important ways: first as a filter of high energy blue light, and second as an antioxidant that quenches and scavenges photo induced reactive oxygen species (ROS). Evidence suggests that lutein consumption is inversely related to eye diseases such as age-related macular degeneration (AMD) and cataracts. This is supported by the finding that lutein (and a stereo isomer, zeaxanthin) are deposited in the lens and the macula lutea, an area of the retina responsible for central and high acuity vision. Human intervention studies show that lutein supplementation results in increased macular pigment and improved vision in patients with AMD and other ocular diseases. Lutein may also serve to protect skin from UV-induced damage and may help reduce the risk of cardiovascular disease. Crystalline lutein is readily absorbed from foods and from dietary supplements whereas, to enter the bloodstream, lutein esters require prior de-esterification by intestinal enzymes. Unlike the hydrocarbon carotenoids which are mainly found in the LDL fraction, xanthophylls like lutein and zeaxanthin are incorporated into both HDL and LDL. Today, lutein can be obtained from the diet in several different ways, including via supplements, and most recently in functional foods. Animal toxicology studies have been performed to established lutein's safety as a nutrient. These studies have contributed to the classification of purified crystalline lutein as generally recognized as safe (GRAS). The achievement of GRAS status for purified crystalline lutein allows for the addition of this form into several food and beverage applications. This achievement speaks directly to the quality and safety of purified lutein.

Safety evaluation of sources of docosahexaenoic acid and arachidonic acid for use in infant formulas in newborn piglets

Human milk provides small quantities of preformed docosahexaenoic acid (DHA) and arachidonic acid (ARA), usually less than 1% of total fatty acids. Vegetable oil blends commonly used in infant formulas have, until recently, provided the essential fatty acid precursors for these long-chain polyunsaturated fatty acids (LCPUFA), but no preformed DHA and ARA. This study evaluated the safety of ingredient sources of DHA and ARA for use in infant formulas in a neonatal piglet model. Newborn piglets were allowed to suckle for 3 days and then divided into 4 feeding groups of 6 males and 6 females. Piglets were bottle-fed at frequent feeding intervals until 19 days of age. The composition of the piglet formulas was modeled after standard milk-based formulas for human infants while meeting nutritional requirements for piglets. Formulas were a control formula (no added DHA or ARA), a DHA formula providing 55 mg DHA/100 Cal, an ARA formula providing 96 mg/100 Cal ARA, and a DHA+ARA formula providing 34 mg DHA and 62 mg ARA/100 Cal. All formulas were equal in fat content and provided approximately 1000 Cal/l. The ARA-rich oil was from a fermentation product of Mortierella alpina (40 wt.% fatty acids as ARA) and DHA was from high DHA tuna oil (25 wt.% fatty acids as DHA). There were no test article related effects of DHA and/or ARA indicative of an adverse health consequence to the animals seen in the clinical signs, body weights, food consumption, clinical chemistry, hematology, organ weights or gross or histopathology. The findings in this neonatal animal study support the safety of these ingredient oil sources of DHA and ARA for use in infant formulas.