The low and high doses administration of lutein improves memory and synaptic plasticity impairment through different mechanisms in a rat model of vascular dementia

BACKGROUND AND AIM

Vascular dementia (VD) is a common type of dementia. This study aimed to evaluate the effects of low and high doses of lutein administration in bilateral-carotid vessel occlusion (2VO) rats.

EXPERIMENTAL PROCEDURE

The rats were divided into the following groups: the control, sham-, vehicle (2VO+V) groups, and two groups after 2VO were treated with lutein 0.5 (2VO+LUT-o.5) and 5mg/kg (2VO+LUT-5). The passive-avoidance and Morris water maze were performed to examine fear and spatial memory. The field-potential recording was used to investigate the properties of basal synaptic transmission (BST), paired-pulse ratio (PPR), as an index for measurement of neurotransmitter release, and long-term potentiation (LTP). The hippocampus was removed to evaluate hippocampal cells, volume, and MDA level.

RESULT

Treatment with low and high doses improves spatial memory and LTP impairment in VD rats, but only the high dose restores the fear memory, hippocampal cell loss, and volume and MDA level. Interestingly, low-dose, but not high-dose, increased PPR. However, BST recovered only in the high-dose treated group.

CONCLUSIONS

Treatment with a low dose might affect neurotransmitter release probability, but a high dose affects postsynaptic processes. It seems likely that low and high doses improve memory and LTP through different mechanisms.

Lutein and Zeaxanthin Supplementation Improves Dynamic Visual and Cognitive Performance in Children: A Randomized, Double-Blind, Parallel, Placebo-Controlled Study

INTRODUCTION

Supplementation with dietary neuro-pigments lutein (L) and zeaxanthin (Z) has been shown to improve many aspects of visual and cognitive function in adults. In this study, we tested whether a similar intervention could improve such outcomes in preadolescent children.

METHODS

Sixty children (age range 5-12 years) were randomized in a 2:1 ratio in this double-blind, placebo-controlled clinical trial. Subjects were supplemented with gummies containing either a combination of 10 mg lutein and 2 mg zeaxanthin (LZ) or placebo for 180 days. Macular pigment optical density (MPOD) was the primary endpoint. The secondary endpoints included serum levels of L and Z, and brain-derived neurotrophic factor (BDNF), critical flicker fusion (CFF), eye strain and fatigue using visual analogue scales (VAS), Children's Sleep Habits Questionnaire-Abbreviated (CSHQ-A), and Creyos Health cognitive domains like attention, focus/concentration, episodic memory and learning, visuospatial working memory, and visuospatial processing speed. Safety was assessed throughout the study on the basis of physical examination, vital signs, clinical laboratory tests, and monitoring of adverse events.

RESULTS

The LZ group showed significant increases in MPOD at all visits post-supplementation, with significant increases as early as day 42 compared to placebo. The LZ group showed significant increases in serum lutein levels, reduced eye strain and fatigue, and improved cognitive performance (focus, episodic memory and learning, visuospatial working memory) at days 90 and 180 compared to placebo. Further, the LZ group showed significant increases in processing speed (CFF), attention, visuospatial processing, and serum Z and BDNF levels on day 180 compared to placebo. No safety concerns were observed.

CONCLUSIONS

Supplementing LZ resulted in increased MPOD levels, along with increased serum levels of L, Z, and BDNF. These changes were associated with improved visual and cognitive performances and reduction in eye strain and eye fatigue in the children receiving LZ gummies. The investigational product was safe and well tolerated.

TRIAL REGISTRATION

http://ctri.nic.in/ Identifier CTRI/2022/05/042364.

Not all carotenoids can reduce the risk of gastric cancer: a systematic review with meta-analysis

BACKGROUND

Gastric cancer is characterized by high invasiveness, heterogeneity, and late diagnosis, leading to high incidence and mortality rates. It is a significant public health concern globally. Early prevention is crucial in reducing the occurrence of gastric cancer, and dietary prevention, particularly focusing on carotenoids, has been considered a convenient and effective approach. However, the association between carotenoid intake and gastric cancer incidence remains controversial.

METHODS

A systematic search was conducted in PubMed, Ovid Embase, Web of Science, and Cochrane databases from inception to January 5, 2023. Two reviewers independently screened search results, extracted relevant data, and evaluated study quality. Statistical analysis was performed using the "metan" command in STATA 16 software. Random-effects or fixed-effects models were chosen based on the magnitude of heterogeneity among studies.

RESULTS

This study included a total of 35 publications, consisting of 23 case-control studies and 12 cohort studies. Meta-analysis of case-control studies showed that alpha-carotene (OR = 0.71, 95% CI: 0.55-0.92), beta-carotene (OR = 0.62, 95% CI: 0.53-0.72), and lutein (OR = 0.82, 95% CI: 0.69-0.97) significantly reduced the risk of gastric cancer, while beta-cryptoxanthin (OR = 0.88, 95% CI: 0.75-1.04) and lycopene (OR = 0.86, 95% CI: 0.73-1.00) showed no significant correlation. Meta-analysis of cohort studies indicated no significant associations between any of the five carotenoids and gastric cancer incidence (alpha-carotene: RR = 0.81, 95% CI: 0.54-1.23; beta-carotene: RR = 0.86, 95% CI: 0.64-1.16; beta-cryptoxanthin: RR = 0.86, 95% CI: 0.64-1.16; lutein: RR = 0.94, 95% CI: 0.69-1.29; lycopene: RR = 0.89, 95% CI: 0.69-1.14).

CONCLUSIONS

The relationship between carotenoids and gastric cancer incidence may vary depending on the type of study conducted. Considering that evidence from cohort studies is generally considered stronger than evidence from case-control studies, and high-quality randomized controlled trials show no significant association between carotenoids and gastric cancer incidence, current evidence does not support the supplementation of carotenoids for gastric cancer prevention. Further targeted research is needed to explore the association between the two.

Assessment of the therapeutic potential of lutein and beta-carotene nanodispersions in a rat model of fibromyalgia

Fibromyalgia (FM) is a chronic disorder characterized by widespread musculoskeletal pain, fatigue, and cognitive impairment. Despite the availability of various treatment options, FM remains a challenging condition to manage. In the present study, we investigated the efficacy of formulated nanodispersions of lutein and beta-carotene in treating FM-related symptoms induced by reserpine in female Wistar rats. Several techniques have been implemented to assess this efficacy at various levels, including biochemical, bioelectrical, and behavioral. Namely, oxidative stress markers, monoamine levels, electrocorticography, pain threshold test, and open field test were conducted on control, FM-induced, and FM-treated groups of animals. Our results provided compelling evidence for the efficacy of carotenoid nanodispersions in treating FM-related symptoms. Specifically, we found that the dual action of the nanodispersion, as both antioxidant and antidepressant, accounted for their beneficial effects in treating FM. With further investigation, nano-carotenoids and particularly nano-lutein could potentially become an effective alternative treatment for patients with FM who do not respond to current treatment options.

The Antioxidant and Anti-Inflammatory Effects of the Main Carotenoids from Tomatoes via Nrf2 and NF-κB Signaling Pathways

Oxidative stress and inflammation are crucial factors in the development of cardiovascular diseases. In previous research, the oxidative stress and inflammation models have frequently been explored independently. In the current study, we investigated the antioxidant and anti-inflammatory effects of tomato extract and its two main carotenoids (lutein and lycopene) with various concentrations using a rat cardiomyocyte model of co-existing oxidative stress and persistent chronic inflammation. It was discovered that the antioxidant effects of 0.5-5 μM lutein, 0.5-5 μM lycopene, and 50-200 μg/mL tomato extract increased in a dose-dependent manner. However, the pro-oxidation effects emerged by measuring the antioxidant-related indices, including the levels of ROS, SOD, and GPX in H9c2 cells as concentrations exceeded those mentioned above. The anti-inflammatory effects of lutein, lycopene, and tomato extract were simultaneously strengthened with higher concentrations, potentially due to the suppression of the NF-κB signaling pathway. Furthermore, high concentrations of lutein, lycopene, and tomato extract potentially regulated Nrf2/HO-1 and NF-κB signaling pathways dependent on TGF-1β and IL-10 to demonstrate high concentrations of pro-oxidation and anti-inflammation effects. Our findings indicate that the dose-effect regulatory mechanisms of antioxidant and anti-inflammatory properties among lutein, lycopene, and tomato extract will be advantageous in developing more effective therapeutic strategies to prevent cardiovascular diseases.

Biomimetic nanoparticles loaded lutein functionalized by macrophage membrane for targeted amelioration pressure overload-induced cardiac fibrosis

Lutein is a strong antioxidant with anti-inflammatory, anti-oxidative and cardioprotective effects and could be a promising candidate for the treatment of hypertensive heart disease (HHD), but is not clinically appealing because of its low oral bioavailability and main distribution in the eyes. To address this, a biomimetic drug delivery system-MMLNPs was established by coating macrophage membranes (MMs) onto lutein-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles (LNPs). This study characterized the physical properties of biomimetic nanoparticles and examined the targeting capability, therapeutic effects and mechanism, and biosecurity of administering them for cardiac fibrosis therapy in the transverse aortic constriction (TAC) model and in vitro. Transmission electron microscope mapping and dynamic light scattering analysis proved that MMLNPs were spherical nanoparticles camouflaged by a layer of cell membrane and had negative zeta potential. Confocal laser scanning microscopy and flow cytometry analysis showed that MMs on the biomimetic nanoparticles hindered the phagocytosis of macrophages and facilitated the targeting of activated endothelial cells. Ex vivo fluorescence imaging experiments demonstrated the targeting of biomimetic nanoparticles to the injured heart. EdU assay indicated that MMLNPs have the same potential to inhibit angiotensin (Ang) II-induced cardiac fibroblast proliferation as free lutein. Furthermore, echocardiography showed that MMLNPs improved cardiac function and structure, and Masson staining and western blotting showed that MMLNPs ameliorated cardiac fibrosis. We found MMLNPs inhibited the interleukin (IL)-11/ERK signaling pathway which was up-regulated in the TAC model compared to the sham-operated mouse. Biochemical testing and hematoxylin and eosin staining proved that the long-term use of MMLNPs lacked biological toxicity. Collectively, MMLNPs might be a promising nanodrug delivery approach to attenuate pressure overload (PO)-induced cardiac fibrosis.

Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a degenerative condition of the back of the eye that occurs in people over the age of 50 years. Antioxidants may prevent cellular damage in the retina by reacting with free radicals that are produced in the process of light absorption. Higher dietary levels of antioxidant vitamins and minerals may reduce the risk of progression of AMD. This is the third update of the review.

OBJECTIVES

To assess the effects of antioxidant vitamin and mineral supplements on the progression of AMD in people with AMD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, one other database, and three trials registers, most recently on 29 November 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared antioxidant vitamin or mineral supplementation to placebo or no intervention, in people with AMD.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane.

MAIN RESULTS

We included 26 studies conducted in the USA, Europe, China, and Australia. These studies enroled 11,952 people aged 65 to 75 years and included slightly more women (on average 56% women). We judged the studies that contributed data to the review to be at low or unclear risk of bias. Thirteen studies compared multivitamins with control in people with early and intermediate AMD. Most evidence came from the Age-Related Eye Disease Study (AREDS) in the USA. People taking antioxidant vitamins were less likely to progress to late AMD (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.58 to 0.90; 3 studies, 2445 participants; moderate-certainty evidence). In people with early AMD, who are at low risk of progression, this means there would be approximately four fewer cases of progression to late AMD for every 1000 people taking vitamins (one fewer to six fewer cases). In people with intermediate AMD at higher risk of progression, this corresponds to approximately 78 fewer cases of progression for every 1000 people taking vitamins (26 fewer to 126 fewer). AREDS also provided evidence of a lower risk of progression for both neovascular AMD (OR 0.62, 95% CI 0.47 to 0.82; moderate-certainty evidence) and geographic atrophy (OR 0.75, 95% CI 0.51 to 1.10; moderate-certainty evidence), and a lower risk of losing 3 or more lines of visual acuity (OR 0.77, 95% CI 0.62 to 0.96; moderate-certainty evidence). Low-certainty evidence from one study of 110 people suggested higher quality of life scores (measured with the Visual Function Questionnaire) in treated compared with non-treated people after 24 months (mean difference (MD) 12.30, 95% CI 4.24 to 20.36). In exploratory subgroup analyses in the follow-on study to AREDS (AREDS2), replacing beta-carotene with lutein/zeaxanthin gave hazard ratios (HR) of 0.82 (95% CI 0.69 to 0.96), 0.78 (95% CI 0.64 to 0.94), 0.94 (95% CI 0.70 to 1.26), and 0.88 (95% CI 0.75 to 1.03) for progression to late AMD, neovascular AMD, geographic atrophy, and vision loss, respectively. Six studies compared lutein (with or without zeaxanthin) with placebo and one study compared a multivitamin including lutein/zeaxanthin with multivitamin alone. The duration of supplementation and follow-up ranged from six months to five years. Most evidence came from the AREDS2 study in the USA; almost all participants in AREDS2 also took the original AREDS supplementation formula. People taking lutein/zeaxanthin may have similar or slightly reduced risk of progression to late AMD (RR 0.94, 95% CI 0.87 to 1.01), neovascular AMD (RR 0.92, 95% CI 0.84 to 1.02), and geographic atrophy (RR 0.92, 95% CI 0.80 to 1.05) compared with control (1 study, 4176 participants, 6891 eyes; low-certainty evidence). A similar risk of progression to visual loss of 15 or more letters was seen in the lutein/zeaxanthin and control groups (RR 0.98, 95% CI 0.91 to 1.05; 6656 eyes; low-certainty evidence). Quality of life (Visual Function Questionnaire) was similar between groups (MD 1.21, 95% CI -2.59 to 5.01; 2 studies, 308 participants; moderate-certainty evidence). One study in Australia randomised 1204 people to vitamin E or placebo with four years of follow-up; 19% of participants had AMD. The number of late AMD events was low (N = 7) and the estimate of effect was uncertain (RR 1.36, 95% CI 0.31 to 6.05; very low-certainty evidence). There was no evidence of any effect of treatment on visual loss (RR 1.04, 95% CI 0.74 to 1.47; low-certainty evidence). There were no data on neovascular AMD, geographic atrophy, or quality of life. Five studies compared zinc with placebo. Evidence largely drawn from the largest study (AREDS) found a lower progression to late AMD over six years (OR 0.83, 95% CI 0.70 to 0.98; 3 studies, 3790 participants; moderate-certainty evidence), neovascular AMD (OR 0.76, 95% CI 0.62 to 0.93; moderate-certainty evidence), geographic atrophy (OR 0.84, 95% CI 0.64 to 1.10; moderate-certainty evidence), or visual loss (OR 0.87, 95% CI 0.75 to 1.00; 2 studies, 3791 participants; moderate-certainty evidence). There were no data on quality of life. Gastrointestinal symptoms were the main reported adverse effect. In AREDS, zinc was associated with a higher risk of genitourinary problems in men, but no difference was seen between high- and low-dose zinc groups in AREDS2. Most studies were too small to detect rare adverse effects. Data from larger studies (AREDS/AREDS2) suggested there may be little or no effect on mortality with multivitamin (HR 0.87, 95% CI 0.60 to 1.25; low-certainty evidence) or lutein/zeaxanthin supplementation (HR 1.06, 95% CI 0.87 to 1.31; very low-certainty evidence), but confirmed the increased risk of lung cancer with beta-carotene, mostly in former smokers.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence suggests that antioxidant vitamin and mineral supplementation (AREDS: vitamin C, E, beta-carotene, and zinc) probably slows down progression to late AMD. People with intermediate AMD have a higher chance of benefiting from antioxidant supplements because their risk of progression is higher than people with early AMD. Although low-certainty evidence suggested little effect with lutein/zeaxanthin alone compared with placebo, exploratory subgroup analyses from one large American study support the view that lutein/zeaxanthin may be a suitable replacement for the beta-carotene used in the original AREDS formula.

[Lutein inhibits the adhesion, invasiveness and metastasis of human prostate cancer PC-3M cells]

OBJECTIVE

To explore the effects of lutein on the adhesion, invasiveness and metastasis of human prostate cancer PC-3M cells and its action mechanism.

METHODS

We divided human prostate cancer PC-3M cells into a control, a low-dose lutein, a medium-dose lutein and a high-dose lutein group, and treated them with 0, 10, 20 and 40 μmol/L lutein, respectively. Then we examined the adhesion of the cells to matrix by cell adhesion assay and the changes in cell pseudopodia by Phalloidin staining, detected the expressions of paxillin, matrix metalloproteinase 2 (MMP-2), MMP-9, recombinant tissue inhibitors of metalloproteinase 1 (TIMP-1), E-cadherin, N-cadherin and vimentin by Western blot, determined the invasiveness and migration of the cells by scratch and Transwell assays, and observed their dynamic movement by high-intension imaging.

RESULTS

Compared with the control, the lutein intervention groups showed significant reduction in the number of the cells adhered to matrix, the number of cell pseudopodia, the expressions of paxillin, MMP-2, MMP-9, N-cadherin and vimentin, the rates of migration, invasion and metastasis, and the distances of displacement and movement of the cells. However, the expressions of TIMP-1 and epithelial-mesenchymal transition-related E-cadherin were upregulated significantly.

CONCLUSION

Lutein can inhibit cell adhesion, reduce the expressions of MMPs, and suppress cell invasion and migration by inhibiting the process of epithelial-mesenchymal transition.

Enhancing children's cognitive function and achievement through carotenoid consumption: The Integrated Childhood Ocular Nutrition Study (iCONS) protocol

Lutein and zeaxanthin (L + Z) are carotenoids that accumulate in neural tissue and potentially confer benefits to cognition. Whereas cross-sectional studies have revealed positive associations between macular carotenoids (MC) and cognition, no studies have investigated whether L + Z supplementation impacts MC and cognition in childhood. Accordingly, the Integrated Childhood Ocular Nutrition Study aims to investigate the impact of L + Z supplementation over 9-months on academic abilities, attentional control, memory, and MC among preadolescent children. Children 8-10 years (N = 288) will enroll in a 9-month double-blind, placebo-controlled, randomized trial. The study is registered and approved as a clinical trial on the U.S. National Library of Medicine http://ClinicalTrials.gov registry (NCT05177679). Participants will be randomized into an active (10 mg lutein+2 mg zeaxanthin) or waitlist placebo-controlled group. Primary outcomes include hippocampal-dependent memory, attentional inhibition, and academic achievement using a spatial reconstruction task, an Eriksen flanker task, and the Kaufman Test of Academic and Educational Achievement 3rd edition, respectively. Secondary outcomes include event-related brain potentials of attentional resource allocation and information processing speed (i.e., P3/P300 amplitude and latency) recorded during the flanker task. Macular pigment optical density (MPOD) will be assessed using heterochromatic flicker photometry. Cognitive assessments will be completed prior to and after completion of the supplementation period. MPOD will be quantified prior to, at the mid-point of (4-5 months), and after (9 months) the supplementation period. It is hypothesized that L + Z supplementation will improve cognition and academic achievement. Further, benefits for cognition and achievement are anticipated to be mediated by increases in MC among treatment group participants.

Choroidal Changes in Blood Flow in Patients with Intermediate AMD after Oral Dietary Supplement Based on Astaxanthin, Bromelain, Vitamin D3, Folic Acid, Lutein, and Antioxidants

Background and Objectives: The aim of this study was to investigate the impact of oral administration of the combination of astaxanthin (AXT), lutein, folic acid, vitamin D3, and bromelain with antioxidants on choroidal blood flow in patients with age-related intermediate macular degeneration (AMD). Materials and Methods: Patients affected by intermediate AMD and treated with daily oral nutritional supplement with AXT, bromelain, vitamin D3, folic acid, lutein, and antioxidants for a period of at least 6 months were included in this retrospective study. A control group homogenous for age and sex was also included in the analysis. All participants underwent a complete ophthalmologic examination, spectral domain optical coherence tomography (SD-OCT), and optical coherence tomography angiography (OCTA) evaluation. Outcome measures were choroidal thickness (CHT) and choriocapillary vessel density (CCVD) after six months of AXT assumption. Results: CCVD values showed statistically significant difference between cases and controls at baseline (p < 0.001) and in the cases during follow-up (p < 0.001). The CHT measurements showed statistically significant difference between cases and controls (p = 0.002) and in the cases during follow-up (p < 0.001). Conclusions: The combined use of structural OCT and OCTA allows for a detailed analysis in vivo of perfusion parameters of the choriocapillaris and choroid and evaluation of changes of choroidal blood flow after oral nutritional supplements that affect blood flow velocity.

A Systematic Review of Carotenoids in the Management of Diabetic Retinopathy

Diabetic retinopathy, which was primarily regarded as a microvascular disease, is the leading cause of irreversible blindness worldwide. With obesity at epidemic proportions, diabetes-related ocular problems are exponentially increasing in the developed world. Oxidative stress due to hyperglycemic states and its associated inflammation is one of the pathological mechanisms which leads to depletion of endogenous antioxidants in retina in a diabetic patient. This contributes to a cascade of events that finally leads to retinal neurodegeneration and irreversible vision loss. The xanthophylls lutein and zeaxanthin are known to promote retinal health, improve visual function in retinal diseases such as age-related macular degeneration that has oxidative damage central in its etiopathogenesis. Thus, it can be hypothesized that dietary supplements with xanthophylls that are potent antioxidants may regenerate the compromised antioxidant capacity as a consequence of the diabetic state, therefore ultimately promoting retinal health and visual improvement. We performed a comprehensive literature review of the National Library of Medicine and Web of Science databases, resulting in 341 publications meeting search criteria, of which, 18 were found eligible for inclusion in this review. Lutein and zeaxanthin demonstrated significant protection against capillary cell degeneration and hyperglycemia-induced changes in retinal vasculature. Observational studies indicate that depletion of xanthophyll carotenoids in the macula may represent a novel feature of DR, specifically in patients with type 2 or poorly managed type 1 diabetes. Meanwhile, early interventional trials with dietary carotenoid supplementation show promise in improving their levels in serum and macular pigments concomitant with benefits in visual performance. These findings provide a strong molecular basis and a line of evidence that suggests carotenoid vitamin therapy may offer enhanced neuroprotective effects with therapeutic potential to function as an adjunct nutraceutical strategy for management of diabetic retinopathy.

Long-term lutein administration attenuates retinal inflammation and functional deficits in early diabetic retinopathy using the Ins2Akita/+ mice

INTRODUCTION

Lutein is a carotenoid whose protective effects in the retina have been reported in various studies. The effect of lutein has not been reported in the retina of the Ins2^Akita/+ mouse, a well-characterized genetic model for diabetic retinopathy (DR) in which the etiology of diabetes is better defined than the chemically induced diabetes. The objective of the present study is to investigate the effect of long-term administration of lutein in early stages of DR using the Ins2^Akita/+ mouse.

RESEARCH DESIGN AND METHODS

Heterozygous male Ins2^Akita/+ and age-matched wild-type mice were used. Lutein was administered to the mice in drinking water starting 6 weeks old daily until analysis at 4.5, 6.5 or 9 months of age. Plain water served as non-treatment control. Microglia were immunostained with ionized calcium-binding adapter molecule 1 (Iba-1) and cluster of differentiation 68 (CD68) in retinal flat-mounts. Vascular endothelial growth factor (VEGF) level in the retina was assessed by enzyme-linked immunosorbent assay (ELISA). Vascular permeability was analyzed in retinal flat-mounts after fluorescein isothiocyanate (FITC)-dextran perfusion. Retinal occludin expression was assessed via Western blots. Retinal function was examined by electroretinography (ERG).

RESULTS

Increased microglial reactivity was detected in the Ins2^Akita/+ mouse retina and was suppressed by lutein. Lutein administration also reduced the upregulation of VEGF in the Ins2^Akita/+ mouse retina. Increased vascular leakage and decreased occludin expression were observed in the Ins2^Akita/+ mouse retina, and these alterations were attenuated by lutein treatment. ERG recordings showed reduced a-wave and b-wave amplitudes in the Ins2^Akita/+ mice. With lutein treatment, the ERG deficits were significantly alleviated.

CONCLUSIONS

We showed beneficial effects of long-term lutein administration in the Ins2^Akita/+ mouse retina, including suppression of retinal inflammation, protection of retinal vasculature and preservation of retinal function. These results point to lutein's potential as a long-term therapeutic intervention for prevention of inflammation and retinal degeneration in patients with early DR.

Particle filter de-noising of voxel-specific time-activity-curves in personalized 177Lu therapy

BACKGROUND

Currently, there is a high interest in ¹⁷⁷Lu targeted radionuclide therapies, which could be attributed to favorable results obtained from ¹⁷⁷Lu compounds targeting neuro-endocrine and prostate tumors. SPECT based dosimetry could be used for deriving dose values for individual voxels, as is the standard in external-beam radiation-therapy (EBRT). For this a time-activity-curve (TAC) at voxel resolution and also a voxel-wise modeling of radiation energy deposition are necessary. But a voxel-wise determination of TACs is problematic, since several confounding factors exist, such as e.g. poor count-statistics or registration inaccuracies, which add noise to the observed activity states. A particle filter (PF) is a class of methods which applies regularization based on a model of the temporal evolution of activity states. The aim of this study is to introduce the application of PFs for de-noising of per-voxel time-activity curves.

METHODS

We applied a PF for de-noising the TACs of 26 patients, who underwent ¹⁷⁷Lu-DOTATOC or -PSMA therapy. The TACs were obtained from fully-quantitative, serial SPECT(/CT) data, acquired at 4h, 24h, 48h, 72h p.i. The model used in the PF was a mono-exponential decay and its free parameters were determined based on objective criteria. The time-integrated activities (TIA) resulting from the PF (PFF) were compared to the results of a mono-exponential fit (SF) of individual voxels in several volumes of interest (kidneys, spleen, tumors). Additionally, an organ-averaged TIA was derived from whole-organ VOIs and subsequent curve-fitting. This whole-organ TIA was also compared to the whole-organ TIAs obtained from summation of the voxel-wise TIAs from PFF and SF.

RESULTS

The number of particles was set to 1000. Optimal values for noise of observations and noise of the model were 0.25 and 0.5, respectively. The deviation of whole-organ TIAs from conventional organ-based dosimetry and the summation of the voxel-wise TIAs was substantial for SF (kidneys -22.3%, spleen -49.6%, tumor -60.0%), as well as for PFF (kidneys -37.1%, spleen -57.9%, tumor -70.9%). The distribution of voxel-wise half-lives resulting from the PFF method was considerably closer to the organ-averaged value, and the number of implausibly long half-lives (>physical HL) was reduced.

CONCLUSION

The PFF leads to voxel-wise half-lives, which are more plausible than those resulting from SF. However, one has to admit that voxel-wise fitting generally leads to considerable deviations from the organ-averaged TIA as obtained by conventional whole-organ evaluation. Unfortunately, we did not have ground-truth TIA of our patient data and proper ground-truth could even be impossible to obtain. Nevertheless, there are strong indicators that particle filtering can be used for reducing voxel-wise TAC noise.

The protective role of lutein on isoproterenol-induced cardiac failure rat model through improving cardiac morphology, antioxidant status via positively regulating Nrf2/HO-1 signalling pathway

Context: Lutein (LU) is a major carotenoid with various pharmacological activities including anti-inflammatory, antioxidant and anti-apoptosis. Objective: The cardioprotective efficacy of LU was determined by evaluating the biochemical and histopathological changes in isoproterenol (ISO) induced myocardial infarction (MI) rat model. Materials and methods: Healthy male albino rats (n = 40) were segregated into 4 equal groups. Group I (control) rats were administered with olive oil, Group II (LU) rats were orally pre-treated with only 40 mg of LU for 28 days, Group III (MI induced) rats were injected (subcutaneously; s.c) with 85 mg/kg of ISO for 2 consecutive days, whereas Group IV (LU + ISO) rats were pre-treated with 40 mg of LU for 28 days before ISO induction. Results: ISO-induced group showed increased infarct size and cardiac/inflammatory/apoptotic markers. However, pre-treatment with LU (28 days) considerably reduced (p < 0.01) the infarct size (14%), lipid peroxidation product (MDA;42%), cardiac markers [(lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB), cardiac troponin T (cTn T)], inflammatory markers [IL-1β, IL-6, tumour necrosis factor alpha (TNF-α), nuclear factor kappa B p65 subunit (NF-κB p65)] and apoptotic markers (caspase-3 and -9). Also, LU significantly improved (p < 0.01) the antioxidants [catalase (CAT), superoxide dismutase (SOD)] as well as markedly upregulated (p < 0.01) the protein expression of HO-1 and Nrf2. Moreover, LU considerably reversed all the histopathological changes and thus exhibits its cardioprotective activity. Conclusion: LU exhibits potent cardioprotective activity against ISO-induced cardiotoxicity and might be recommended with standard cardioprotective agents for treating various MI-related complications.

A Deep Phenotype Association Study Reveals Specific Phenotype Associations with Genetic Variants in Age-related Macular Degeneration: Age-Related Eye Disease Study 2 (AREDS2) Report No. 14

PURPOSE

Age-related macular degeneration (AMD), a multifactorial disease with variable phenotypic presentation, was associated with 52 single nucleotide polymorphisms (SNPs) at 34 loci in a genome-wide association study (GWAS). These genetic variants could modulate different biological pathways involved in AMD, contributing to phenotypic variability. To better understand the effects of these SNPs, we performed a deep phenotype association study (DeePAS) in the Age-Related Eye Disease Study 2 (AREDS2), followed by replication using AREDS participants, to identify genotype associations with AMD and non-AMD ocular and systemic phenotypes.

DESIGN

Cohort study.

PARTICIPANTS

AREDS and AREDS2 participants.

METHODS

AREDS2 participants (discovery cohort) had detailed phenotyping for AMD; other eye conditions; cardiovascular, neurologic, gastrointestinal, and endocrine disease; cognitive function; serum nutrient levels; and others (total of 139 AMD and non-AMD phenotypes). Genotypes of the 52 GWAS SNPs were obtained. The DeePAS was performed by correlating the 52 SNPs to all phenotypes using logistic and linear regression models. Associations that reached Bonferroni-corrected statistical significance were replicated in AREDS.

MAIN OUTCOME MEASURES

Genotype-phenotype associations.

RESULTS

A total of 1776 AREDS2 participants had 5 years follow-up; 1435 AREDS participants had 10 years. The DeePAS revealed a significant association of the rs3750846 SNP at the ARMS2/HTRA1 locus with subretinal/sub-retinal pigment epithelial (RPE) hemorrhage related to neovascular AMD (odds ratio 1.55 [95% confidence interval 1.31-1.84], P = 2.67 × 10-7). This novel association remained significant after conditioning on participants with neovascular AMD (P = 2.42 × 10-4). Carriers of rs3750846 had poorer visual acuity during follow-up (P = 6.82 × 10-7) and were more likely to have a first-degree relative with AMD (P = 5.38 × 10-6). Two SNPs at the CFH locus, rs10922109 and rs570618, were associated with the drusen area in the Early Treatment Diabetic Retinopathy Study Report (ETDRS) grid (P = 2.29 × 10-11 and P = 3.20 × 10-9, respectively) and the center subfield (P = 1.24 × 10-9 and P = 6.68 × 10-8, respectively). SNP rs570618 was additionally associated with the presence of calcified drusen (P = 5.38 × 10-6). Except for positive family history of AMD with rs3750846, all genotype-phenotype associations were significantly replicated in AREDS. No pleiotropic associations were identified.

CONCLUSIONS

The association of the SNP at the ARMS2/HTRA1 locus with subretinal/sub-RPE hemorrhage and poorer visual acuity and of SNPs at the CFH locus with drusen area may provide new insights in pathophysiological pathways underlying different stages of AMD.

Association of Mortality with Ocular Diseases and Visual Impairment in the Age-Related Eye Disease Study 2: Age-Related Eye Disease Study 2 Report Number 13

PURPOSE

To evaluate the association of mortality with visual acuity (VA) impairment, age-related macular degeneration (AMD), and cataract surgery.

DESIGN

Cohort study.

PARTICIPANTS

Participants with at least intermediate AMD enrolled in a randomized controlled clinical trial of lutein/zeaxanthin and/or omega-3 fatty acids, the Age-Related Eye Disease Study 2 (AREDS2), for treatment of AMD and cataract.

METHODS

Baseline and annual eye examinations included best-corrected visual acuity (BCVA) assessments, slit-lamp examinations, and stereoscopic fundus photographs that were centrally graded for development of late AMD (central geographic atrophy or neovascular AMD) or pseudophakia. Cause-specific mortality was determined on the basis of the International Classification of Diseases 9th or 10th Revision codes. Risk of all-cause and cause-specific mortality was assessed with Cox proportional hazards models adjusted for age, sex, AMD severity, VA, history of cataract surgery, and assigned AREDS2 study treatment. Analyses included baseline covariates: race, education, smoking status, diabetes, and cardiovascular disease.

RESULTS

During follow-up (median 5 years), 368 (9%) of the 4203 AREDS2 participants died. Participants with neovascular AMD in 1 eye at baseline had a statistically significant increased risk for mortality compared with participants with no or few drusen (hazard ratio [HR], 1.56; 95% confidence interval [CI], 1.21-2.01; P < 0.001). Poorer survival was associated with bilateral cataract surgery before enrollment compared with baseline bilateral phakia (HR, 1.63; 95% CI, 1.29-2.07; P < 0.001) and with BCVA of less than 20/40 compared with participants with 20/40 or better (HR, 1.56; 95% CI, 1.06-2.30; P = 0.024), adjusted for age, sex, and statistically significant covariates. Participants who received antivascular endothelial growth factor therapies for neovascular AMD had decreased mortality compared with those who did not (HR, 0.71; 95% CI, 0.57-0.88; P = 0.002). The association between all-cause mortality and AREDS2 treatment whether assessing the main or individual treatment effect was not significantly different (omega-3 fatty acids main effect HR, 1.18; 95% CI, 0.96-1.45; P = 0.12; lutein/zeaxanthin main effect HR, 1.04; 95% CI, 0.85-1.28; P = 0.71).

CONCLUSIONS

In AREDS2, the presence of late AMD, bilateral cataract surgery, and VA less than 20/40 was associated with decreased survival. However, oral supplementation with omega-3 fatty acids, lutein plus zeaxanthin, zinc, or beta-carotene had no statistically significant impact on mortality.

Lutein protects against severe traumatic brain injury through anti‑inflammation and antioxidative effects via ICAM‑1/Nrf‑2

Many studies have reported that lutein may exert its biological activities, including anti‑inflammation, anti‑oxidase and anti‑apoptosis, through effects on reactive oxygen species (ROS). Thus, lutein may prevent the damaging activities of ROS in cells. The current study investigated the effect of lutein against severe traumatic brain injury (STBI) and examined the mechanism of this protective effect. Sprague‑Dawley rats were randomly divided into 5 groups: Control group, STBI model group, 40 mg/kg lutein‑treated group, 80 mg/kg lutein‑treated group and 160 mg/kg lutein‑treated group. In this study, lutein protects against STBI, suppressed, interleukin (IL)‑1β, IL‑6 and monocyte chemoattractant protein‑1 expression, reduced serum ROS levels, and reduced superoxide dismutase and glutathione peroxidase activities in STBI rats. Treatment with lutein effectively downregulated the expression of NF‑κB p65 and cyclooxygenase‑2, intercellular adhesion molecule (ICAM)‑1 protein, and upregulated nuclear factor erythroid 2 like 2 (Nrf‑2) and endothelin‑1 protein levels in STBI rats. These findings demonstrated that lutein protects against STBI, has anti‑inflammation and antioxidative effects and alters ICAM‑1/Nrf‑2 expression, which may be a novel therapeutic for STBI the clinic.

[Behind blue eyes – the evidence for ocular nutritional supplements on the Swedish market]

Behind blue eyes - the evidence for ocular nutritional supplements on the Swedish market Health claims for food are harmonized in the European Union by the European Food Safety Authority (EFSA). Nutritional supplements containing vitamin A or B, docosahexaenoic acid or zinc are allowed to state in their marketing that they preserve vision. This decision is based only on studies of cell metabolism and deficiency diseases and not on clinical interventions. A preventive effect on progression of age-related macular degeneration has however been proven with the AREDS-formula, with an absolute risk reduction for severe visual loss of 6% in certain groups. This treatment may however be associated with considerable side effects. Only 2 of the 25 nutritional supplements for preserved vision available on the Swedish market today follows the AREDS-formula. The present marking of ocular nutritional supplements might therefore be misleading for the customer.

Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration

BACKGROUND

It has been proposed that antioxidants may prevent cellular damage in the retina by reacting with free radicals that are produced in the process of light absorption. Higher dietary levels of antioxidant vitamins and minerals may reduce the risk of progression of age-related macular degeneration (AMD).

OBJECTIVES

The objective of this review was to assess the effects of antioxidant vitamin or mineral supplementation on the progression of AMD in people with AMD.

SEARCH METHODS

We searched CENTRAL (2017, Issue 2), MEDLINE Ovid (1946 to March 2017), Embase Ovid (1947 to March 2017), AMED (1985 to March 2017), OpenGrey (System for Information on Grey Literature in Europe, the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 29 March 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared antioxidant vitamin or mineral supplementation (alone or in combination) to placebo or no intervention, in people with AMD.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed risk of bias in the included studies and extracted data. One author entered data into RevMan 5; the other author checked the data entry. We graded the certainty of the evidence using GRADE.

MAIN RESULTS

We included 19 studies conducted in USA, Europe, China, and Australia. We judged the trials that contributed data to the review to be at low or unclear risk of bias.Nine studies compared multivitamins with placebo (7 studies) or no treatment (2 studies) in people with early and moderate AMD. The duration of supplementation and follow-up ranged from nine months to six years; one trial followed up beyond two years. Most evidence came from the Age-Related Eye Disease Study (AREDS) in the USA. People taking antioxidant vitamins were less likely to progress to late AMD (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.58 to 0.90; 2445 participants; 3 RCTs; moderate-certainty evidence). In people with very early signs of AMD, who are at low risk of progression, this would mean that there would be approximately 4 fewer cases of progression to late AMD for every 1000 people taking vitamins (1 fewer to 6 fewer cases). In people at high risk of progression (i.e. people with moderate AMD) this would correspond to approximately 8 fewer cases of progression for every 100 people taking vitamins (3 fewer to 13 fewer). In one study of 1206 people, there was a lower risk of progression for both neovascular AMD (OR 0.62, 95% CI 0.47 to 0.82; moderate-certainty evidence) and geographic atrophy (OR 0.75, 95% CI 0.51 to 1.10; moderate-certainty evidence) and a lower risk of losing 3 or more lines of visual acuity (OR 0.77, 95% CI 0.62 to 0.96; 1791 participants; moderate-certainty evidence). Low-certainty evidence from one study of 110 people suggested higher quality of life scores (National Eye Institute Visual Function Questionnaire) in treated compared with the non-treated people after 24 months (mean difference (MD) 12.30, 95% CI 4.24 to 20.36). Six studies compared lutein (with or without zeaxanthin) with placebo. The duration of supplementation and follow-up ranged from six months to five years. Most evidence came from the AREDS2 study in the USA. People taking lutein or zeaxanthin may have similar or slightly reduced risk of progression to late AMD (RR 0.94, 95% CI 0.87 to 1.01; 6891 eyes; low-certainty evidence), neovascular AMD (RR 0.92, 95% CI 0.84 to 1.02; 6891 eyes; low-certainty evidence), and geographic atrophy (RR 0.92, 95% CI 0.80 to 1.05; 6891 eyes; low-certainty evidence). A similar risk of progression to visual loss of 15 or more letters was seen in the lutein and control groups (RR 0.98, 95% CI 0.91 to 1.05; 6656 eyes; low-certainty evidence). Quality of life (measured with Visual Function Questionnaire) was similar between groups in one study of 108 participants (MD 1.48, 95% -5.53 to 8.49, moderate-certainty evidence). One study, conducted in Australia, compared vitamin E with placebo. This study randomised 1204 people to vitamin E or placebo, and followed up for four years. Participants were enrolled from the general population; 19% had AMD. The number of late AMD events was low (N = 7) and the estimate of effect was uncertain (RR 1.36, 95% CI 0.31 to 6.05, very low-certainty evidence). There were no data on neovascular AMD or geographic atrophy.There was no evidence of any effect of treatment on visual loss (RR 1.04, 95% CI 0.74 to 1.47, low-certainty evidence). There were no data on quality of life. Five studies compared zinc with placebo. The duration of supplementation and follow-up ranged from six months to seven years. People taking zinc supplements may be less likely to progress to late AMD (OR 0.83, 95% CI 0.70 to 0.98; 3790 participants; 3 RCTs; low-certainty evidence), neovascular AMD (OR 0.76, 95% CI 0.62 to 0.93; 2442 participants; 1 RCT; moderate-certainty evidence), geographic atrophy (OR 0.84, 95% CI 0.64 to 1.10; 2442 participants; 1 RCT; moderate-certainty evidence), or visual loss (OR 0.87, 95% CI 0.75 to 1.00; 3791 participants; 2 RCTs; moderate-certainty evidence). There were no data reported on quality of life.Very low-certainty evidence was available on adverse effects because the included studies were underpowered and adverse effects inconsistently reported.

AUTHORS' CONCLUSIONS

People with AMD may experience some delay in progression of the disease with multivitamin antioxidant vitamin and mineral supplementation. This finding was largely drawn from one large trial, conducted in a relatively well-nourished American population. We do not know the generalisability of these findings to other populations. Although generally regarded as safe, vitamin supplements may have harmful effects. A systematic review of the evidence on harms of vitamin supplements is needed. Supplements containing lutein and zeaxanthin are heavily marketed for people with age-related macular degeneration but our review shows they may have little or no effect on the progression of AMD.

Phospholipid oxidation and carotenoid supplementation in Alzheimer's disease patients

Alzheimer's disease (AD) is a progressive, neurodegenerative disease, characterised by decline of memory, cognitive function and changes in behaviour. Generic markers of lipid peroxidation are increased in AD and reactive oxygen species have been suggested to be involved in the aetiology of cognitive decline. Carotenoids are depleted in AD serum, therefore we have compared serum lipid oxidation between AD and age-matched control subjects before and after carotenoid supplementation. The novel oxidised phospholipid biomarker 1-palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC) was analysed using electrospray ionisation tandem mass spectrometry (MS) with multiple reaction monitoring (MRM), 8-isoprostane (IsoP) was measured by ELISA and ferric reducing antioxidant potential (FRAP) was measured by a colorimetric assay. AD patients (n=21) and healthy age-matched control subjects (n=16) were supplemented with either Macushield™ (10mg meso-zeaxanthin, 10mg lutein, 2mg zeaxanthin) or placebo (sunflower oil) for six months. The MRM-MS method determined serum POVPC sensitively (from 10µl serum) and reproducibly (CV=7.9%). At baseline, AD subjects had higher serum POVPC compared to age-matched controls, (p=0.017) and cognitive function was correlated inversely with POVPC (r=-0.37; p=0.04). After six months of carotenoid intervention, serum POVPC was not different in AD patients compared to healthy controls. However, POVPC was significantly higher in control subjects after six months of carotenoid intervention compared to their baseline (p=0.03). Serum IsoP concentration was unrelated to disease or supplementation. Serum FRAP was significantly lower in AD than healthy controls but was unchanged by carotenoid intervention (p=0.003). In conclusion, serum POVPC is higher in AD patients compared to control subjects, is not reduced by carotenoid supplementation and correlates with cognitive function.

Effects of Mixed Carotenoids on Adipokines and Abdominal Adiposity in Children: A Pilot Study

CONTEXT

Carotenoids have been implicated in the regulation of adipocyte metabolism.

OBJECTIVE

To compare the effects of mixed-carotenoid supplementation (MCS) versus placebo on adipokines and the accrual of abdominal adiposity in children with obesity.

DESIGN AND SETTING

Randomized (1:1), double-blind, placebo-controlled intervention trial to evaluate the effects of MCS over 6 months in a subspecialty clinic.

PARTICIPANTS

Twenty (6 male and 14 female) children with simple obesity [body mass index (BMI) > 90%], a mean age (± standard deviation) of 10.5 ± 0.4 years, and Tanner stage I to V were enrolled; 17 participants completed the trial.

INTERVENTION

MCS (which contains β-carotene, α-carotene, lutein, zeaxanthin, lycopene, astaxanthin, and γ-tocopherol) or placebo was administered daily.

MAIN OUTCOME MEASURES

Primary outcomes were change in β-carotene, abdominal fat accrual (according to magnetic resonance imaging), and BMI z-score; secondary outcomes were adipokines and markers of insulin resistance.

RESULTS

Cross-sectional analysis of β-carotene showed inverse correlation with BMI z-score, waist-to-height ratio, visceral adipose tissue, and subcutaneous adipose tissue (SAT) at baseline. MCS increased β-carotene, total adiponectin, and high-molecular-weight adiponectin compared with placebo. MCS led to a greater reduction in BMI z-score, waist-to-height ratio, and SAT compared with placebo. The percentage change in β-carotene directly correlated with the percentage change in SAT.

CONCLUSIONS

The decrease in BMI z-score, waist-to-height ratio, and SAT and the concomitant increase in the concentration of β-carotene and high-molecular-weight adiponectin by MCS suggest the putative beneficial role of MCS in children with obesity.

Lutein, Zeaxanthin and Meso-zeaxanthin Supplementation Associated with Macular Pigment Optical Density

The purpose of this study was to evaluate the effects of lutein, zeaxanthin and meso-zeaxanthin on macular pigment optical density (MPOD) in randomized controlled trials (RCTs) among patients with age-related macular degeneration (AMD) and healthy subjects. Medline, Embase, Web of Science and Cochrane Library databases was searched through May 2016. Meta-analysis was conducted to obtain adjusted weighted mean differences (WMD) for intervention-versus-placebo group about the change of MPOD between baseline and terminal point. Pearson correlation analysis was used to determine the relationship between the changes in MPOD and blood xanthophyll carotenoids or baseline MPOD levels. Twenty RCTs involving 938 AMD patients and 826 healthy subjects were identified. Xanthophyll carotenoids supplementation was associated with significant increase in MPOD in AMD patients (WMD, 0.07; 95% CI, 0.03 to 0.11) and healthy subjects (WMD, 0.09; 95% CI, 0.05 to 0.14). Stratified analysis showed a greater increase in MPOD among trials supplemented and combined with meso-zeaxanthin. Additionally, the changes in MPOD were related with baseline MPOD levels (r_AMD = −0.43, p = 0.06; r_{healthy subjects} = −0.71, p < 0.001) and blood xanthophyll carotenoids concentration (r_AMD = 0.40, p = 0.07; r_{healthy subjects} = 0.33, p = 0.05). This meta-analysis revealed that lutein, zeaxanthin and meso-zeaxanthin supplementation improved MPOD both in AMD patients and healthy subjects with a dose-response relationship.

Nonneovascular Age-Related Macular Degeneration

The discovery of several genetic variants associated with an increased risk for age-related macular degeneration (AMD) has led to a completely new understanding of AMD. In addition to the known modifiable risk factors, genetic risk factors may also help to assess the risk to progress to nonneovascular AMD. Recently published primary studies have indicated that genetic risk analysis may be valuable in the selection of the currently available antioxidant therapy. So far, the best evidence for preventing progression to nonneovascular AMD comes from the Age-Related Eye Disease Studies (AREDS) I and II. These studies indicate that high doses of antioxidants can reduce the risk of progression to the advanced form of the disease. However, the recent evaluation of the addition of either lutein and zeaxanthin, or ω-3 long-chain polyunsaturated fatty acids, or both, to the established AREDS I formulation did not significantly reduce the risk of developing advanced AMD. There is clearly a large unmet medical need for new therapeutic options for nonneovascular AMD. The modulation of the complement cascade is - despite initially disappointing outcomes obtained with blocking complement factor 5 - currently the most promising approach to the treatment of nonneovascular AMD.

Changes in Macular Pigment Optical Density and Serum Lutein Concentration in Japanese Subjects Taking Two Different Lutein Supplements

PURPOSE

To investigate macular pigment optical density (MPOD) and serum concentration changes of lutein in Japanese subjects participating in a clinical trial in which two formulations of lutein and zeaxanthin supplements with different physiochemical properties are used.

METHODS

Thirty-six healthy volunteers were recruited into this prospective, randomized, parallel-group, double-masked comparative study at a single institute. Two products were used, FloraGLO® (Kemin Japan) and XanMax® (Katra Phytochem). The lutein particle size and zeaxanthin concentrations differed between the formulations. The subjects consumed one of the two supplements for a duration of up to 6 months. MPOD levels were measured by resonance Raman spectrometry at baseline and once a month until the end of the study. Serum lutein concentration was measured at baseline, month 3, and month 6. The subjects were also tested for contrast sensitivity, glare sensitivity, visual acuity, and in addition had a focal electroretinogram measured.

RESULTS

The mean serum lutein concentrations increased significantly after the first three months, but the mean MPOD levels in either supplement group did not show any statistically significant increase. A detailed analysis, however, revealed three response patterns in both groups for the increase of MPOD levels and serum lutein concentration, i.e. "retinal responders", who had an increase of both MPOD levels and serum lutein concentrations (n = 13), "retinal non-responders", who had only increased serum concentrations and no change in MPOD levels (n = 20), and "retinal and serum non-responders", who had neither MPOD level nor plasma concentration increases (n = 3). The subjects with low MPOD levels at baseline appeared to show increased MPOD levels at the 6 month time point upon lutein supplementation (r = -0.4090, p = 0.0133). Glare sensitivity improved in retinal responders in both supplement groups, while there were no remarkable changes in contrast sensitivity.

CONCLUSIONS

No statistically significant differences could be detected for MPOD levels and serum lutein concentrations between the two investigated lutein supplement formulations. Responses to lutein supplementation regarding MPOD levels and serum lutein concentrations varied between subjects. Subjects with lower MPOD levels at baseline responded well to lutein supplementation. However, since the number of subjects was low, a further study with more subjects is needed to prove that subjects with low MPOD levels will benefit from lutein supplementation.

TRIAL REGISTRATION

UMIN-CTR UMIN000004593.

Association between higher plasma lutein, zeaxanthin, and vitamin C concentrations and longer telomere length: results of the Austrian Stroke Prevention Study

OBJECTIVES

To examine the association between plasma concentrations of antioxidative micronutrients and leukocyte telomere length (LTL) in elderly adults.

DESIGN

Cross-sectional cohort study.

SETTING

Austrian Stroke Prevention Study, a population-based cohort study on brain aging.

PARTICIPANTS

Individuals with a mean age of 66 ± 7 (n = 786; 58% female).

MEASUREMENTS

Concentrations of vitamin C, lutein, zeaxanthin, β-cryptoxanthin, canthaxanthin, lycopene, α- and γ-tocopherol, α- and β-carotene, and retinol in plasma, advanced oxidation protein products as a measure of oxidative stress in serum, and LTL were measured. Vitamins and carotenoids were measured using high-performance liquid chromatography, advanced oxidation protein products using spectrophotometry, and telomere length using quantitative real-time polymerase chain reaction.

RESULTS

Multiple linear regression analyses with adjustment for age and sex demonstrated that higher lutein, zeaxanthin, and vitamin C concentrations were strongly associated with longer telomere length. The associations were independent of body mass index, maximum oxygen uptake, and vascular risk factors and were not mediated by advanced oxidation protein products content.

CONCLUSION

This study provides first evidence that higher lutein, zeaxanthin, and vitamin C concentrations in plasma are associated with longer LTL in normal elderly persons and suggest a protective role of these vitamins in telomere maintenance.

Oxidative stress in rats with hyperhomo-cysteinemia and intervention effect of lutein

AIM

The current study aims to explore the possible molecular mechanism of hyperhomocysteinemia (HHcy) mediated atherosclerosis (AS) and to find an effective intervention method for AS.

MATERIALS AND METHODS

A total of 40 Wistar rats were equalized into four groups: blank control, HHcy, folacin intervention, and lutein intervention groups. HHcy rat models were established. The intervention groups were respectively lavaged with folacin and lutein. Oxidative stress states, the levels of nitric oxide (NO) and endothelin-1 (ET-1), as well as the expression of nuclear factor (NF)-κB p65 and intercellular adhesion molecule (ICAM)-1 were compared.

RESULTS

In the HHcy rats, the activity of serum superoxide dismutase (SOD) and glutathione peroxidase (GPx) significantly decreased, whereas the malondialdehyde content and hydroxyl radical level noticeably increased, indicating that the rats stayed in aggravated oxidative stress states. Lutein intervention inhibited HHcy-induced oxidative stress excitement. In the HHcy rats, the NO level significantly decreased, whereas the ET-1 level significantly increased, indicating that HHcy mediated vascular endothelial dysfunction. Lutein reversed such dysfunction. In the HHcy rats, the mRNA and protein expression of SOD2 and GPX1 in the aortic wall tissue decreased, whereas that of NF-κB p65 and ICAM-1 increased. Lutein significantly upregulated the mRNA and protein expression of SOD2 and GPx1 and downregulated the expression of NF-κB p65 and ICAM-1.

CONCLUSIONS

Oxidative stress and inflammation are the important mechanisms of HHcy-mediated AS. In particular, HHcy-induced aggravated oxidative stress may function as the initial AS-mediating mechanism, upregulating the expression of NF-κB p65 and ICAM-1 and thereby becoming associated with AS. Lutein noticeably intervenes in and inhibits Hcy-mediated oxidative stress excitement and downregulates the expression of inflammation-associated informational molecules.

Age-Related Eye Disease Study 2 Research Group. Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial

IMPORTANCE

Oral supplementation with the Age-Related Eye Disease Study (AREDS) formulation (antioxidant vitamins C and E, beta carotene, and zinc) has been shown to reduce the risk of progression to advanced age-related macular degeneration (AMD). Observational data suggest that increased dietary intake of lutein + zeaxanthin (carotenoids), omega-3 long-chain polyunsaturated fatty acids (docosahexaenoic acid [DHA] + eicosapentaenoic acid [EPA]), or both might further reduce this risk.

OBJECTIVES

To determine whether adding lutein + zeaxanthin, DHA + EPA, or both to the AREDS formulation decreases the risk of developing advanced AMD and to evaluate the effect of eliminating beta carotene, lowering zinc doses, or both in the AREDS formulation.

DESIGN, SETTING, AND PARTICIPANTS

The Age-Related Eye Disease Study 2 (AREDS2), a multicenter, randomized, double-masked, placebo-controlled phase 3 study with a 2 × 2 factorial design, conducted in 2006-2012 and enrolling 4203 participants aged 50 to 85 years at risk for progression to advanced AMD with bilateral large drusen or large drusen in 1 eye and advanced AMD in the fellow eye.

INTERVENTIONS

Participants were randomized to receive lutein (10 mg) + zeaxanthin (2 mg), DHA (350 mg) + EPA (650 mg), lutein + zeaxanthin and DHA + EPA, or placebo. All participants were also asked to take the original AREDS formulation or accept a secondary randomization to 4 variations of the AREDS formulation, including elimination of beta carotene, lowering of zinc dose, or both.

MAIN OUTCOMES AND MEASURES

Development of advanced AMD. The unit of analyses used was by eye.

RESULTS

Median follow-up was 5 years, with 1940 study eyes (1608 participants) progressing to advanced AMD. Kaplan-Meier probabilities of progression to advanced AMD by 5 years were 31% (493 eyes [406 participants]) for placebo, 29% (468 eyes [399 participants]) for lutein + zeaxanthin, 31% (507 eyes [416 participants]) for DHA + EPA, and 30% (472 eyes [387 participants]) for lutein + zeaxanthin and DHA + EPA. Comparison with placebo in the primary analyses demonstrated no statistically significant reduction in progression to advanced AMD (hazard ratio [HR], 0.90 [98.7% CI, 0.76-1.07]; P = .12 for lutein + zeaxanthin; 0.97 [98.7% CI, 0.82-1.16]; P = .70 for DHA + EPA; 0.89 [98.7% CI, 0.75-1.06]; P = .10 for lutein + zeaxanthin and DHA + EPA). There was no apparent effect of beta carotene elimination or lower-dose zinc on progression to advanced AMD. More lung cancers were noted in the beta carotene vs no beta carotene group (23 [2.0%] vs 11 [0.9%], nominal P = .04), mostly in former smokers.

CONCLUSIONS AND RELEVANCE

Addition of lutein + zeaxanthin, DHA + EPA, or both to the AREDS formulation in primary analyses did not further reduce risk of progression to advanced AMD. However, because of potential increased incidence of lung cancer in former smokers, lutein + zeaxanthin could be an appropriate carotenoid substitute in the AREDS formulation.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00345176.

The effect of night vision goggles on the retinocortical bioelectrical activity and its improvement by food supplement

AIM

To investigate the effect of luminance variations, as well as the oral administration of a food supplement, on the visual bioelectric response while using of Night Vision Goggles (NVG).

METHODS

Two trials were performed, both enrolling healthy male aircrew members wearing NVG, and recording Visual Evoked Potentials (VEPs) from scalp electrodes. Both foveal and parafoveal response were evaluated. Latency and amplitude, P100 peak, were measured. In the first set of measurements, VEPs parameters were recorded during unaided photopic conditions and mesopic conditions while using 3rd generation plus NVG (ANVIS 9). In the second set of experiments, after the first basal electrophysiological investigation during mesopic conditions using NVG, patients started a 45 days oral treatment, during which they took 3 tablets per day of a food supplement. The tablets contained a mix of anthocyanosides, procyanidolic oligomers, lutein and vitamins A and E. At the end of this treatment, patients were tested again by pattern-reversal VEP investigation during aided vision condition (wearing NVG) in a mesopic environment.

RESULTS

VEPs parameters, statistically evaluated using a two tailed paired t-test, showed that latency and amplitude were respectively increased (p < 0.001 and p < 0.01 for 15' and 60' minutes of arc) and decreased (p < 0.05) when measured using NVG with respect to unaided basal conditions. Furthermore, the VEP response in NVG aided vision was positively affected by the oral treatment with the food supplement, showing a significant (p < 0.05) decrease of latency and increase of amplitude.

CONCLUSION

The use of NVG impairs the VEP response, and such effect is effectively counteracted by the oral treatment with a food supplement containing a combination of sight improving molecules that might enhance foveal selectivity, central photoreceptors sensitivity and magnocellular fibers effectiveness.

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.

The effect of lutein supplementation on visual fatigue: a psychophysiological analysis

We used psychophysiological technology to examine the effect of an oral supplement, a combination of lutein, zeaxanthin and blackcurrant extract (LUT), on visual fatigue, within the context of a randomized, double-blind, placebo-controlled cross-over trial. The LUT supplement and placebo samples were randomly assigned to thirteen participants, who took the samples for two LUT (and vice versa) for another 2 week. Each participant completed visual proof reading tasks for 2h during each of four testing sessions. Saccade tests were administered before and after the proof reading task, during which the participants moved their eyes back and forth between two targets positioned in the center of two checkerboards. We recorded EEG, EOG, heart rate, and facial muscle potential/performance during the saccade tests. Blood pressure was measured and subjective fatigue and stress scores were collected before and after the proof reading task. We averaged EEG starting at saccade offset in order to analyze eye fixation related potentials (EFRP). Our results suggested that the proof reading task induced visual fatigue. An analysis of EFRP and other psychophysiological data revealed significant differences between the LUT and placebo conditions. These results suggest that supplementation with LUT could help to reduce symptoms of visual fatigue.

Dietary supplements commonly used for prevention

The use of complimentary and alternative medicine is on the rise. This article reviews some of the commonly used herbal supplements and others focusing mainly on disease prevention. A summary table of medical conditions is provided, and when possible, a summary of efficacy and safety is provided to facilitate decision making.

[Lutein and eye health--current state of discussion]

Due to increased life expectancy the number of people with age-related diseases like age-related macular degeneration (AMD) will grow. Currently AMD is incurable and only a few therapeutic strategies are available. Therefore prevention becomes more important. Protective effects related to eye health are discussed for the two carotenoids lutein and zeaxanthin. Meanwhile both substances are offered as food supplements to a great extent. Both carotenoids lutein and zeaxanthin are accumulated in the retina, especially in the macula lutea. They are able to absorb blue light, which damages photoreceptors and pigmentary epithelium. Due to their antioxidative properties they can reduce changes in membrane permeability via quenching reactive oxygen species and free radicals. Research studies suppose lutein and zeaxanthin may contribute to improvement of vision in patients with AMD and other eye diseases. Based on the scientific rationale, these carotenoids may be effective in the prevention of age-related eye diseases. However, this issue has to be examined in a differentiated way.

[Light-absorbing and antiradical properties of a product with lutein and zeaxanthin in vitro and kinetics of carotinoids at single oral administration on rats]

Light-absorbing and antiradical properties of the new product on a basis of lutein and zeaxanthin for correction of eye diseases in model system of initiated oxidation of isopropylbenzene were investigated. It is shown, that the product is the effective light-absorbing agent and inhibitor of free-radical oxidation in vitro. In experiments on animals (rat) the pharmacokinetics of the product was investigated at single oral administration. A simple, specific and sensitive RP-HPLC method for the determination of lutein in rat plasma was developed, which was applied to pharmacokinetic investigation in rats after oral administration of lutein at dose 20 mg/kg. It was established, that the peak plasma levels was achieved to 2 hour and the mean elimination half life was 2,4 hours.

Age related macular degeneration--should your patients be taking additional supplements?

BACKGROUND

The use of over-the-counter complementary medicines and supplements is growing. Patients with age related macular degeneration (AMD) are likely to have heard of, or are possibly already taking, additional supplements that may increase their chances of retaining useful eyesight.

OBJECTIVE

This article looks specifically at evidence regarding the effects of over-the-counter oral supplements such as antioxidants and omega-3 fatty acids on AMD.

DISCUSSION

Diet manipulation and supplementation has a role to play in modifying the risk of disease progression in AMD patients. A combination of vitamins C and E, beta carotene, zinc oxide and cupric oxide has been shown to reduce the rate of visual loss in dry AMD. However, commercially available preparations do not always recommend the correct intake that would match levels found in clinical trials. Other carotenoids such as lutein and zeaxanthin may also be beneficial, intake of these can be increased by altering diet alone. Other useful dietary changes include reducing both animal and vegetable fats and increasing the consumption of fish and nuts.

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.

LAST II: Differential temporal responses of macular pigment optical density in patients with atrophic age-related macular degeneration to dietary supplementation with xanthophylls

BACKGROUND

Age-related macular degeneration (ARMD) is the leading cause of vision loss in aging Western societies. The objective of the Lutein Antioxidant Supplementation Trial (LAST) was to determine whether specific dietary interventions increased macular pigment optical density (MPOD) and visual function in patients with atrophic ARMD. The current objective of LAST II is to discern those specific characteristics that increase MPOD, i.e., that might differentiate a responder from a nonresponder.

METHODS

The LAST study was a prospective, 12-month, randomized, double-masked, placebo-controlled trial conducted at an urban midwestern Veterans Administation Hospital from August 1999 to May 2001. Ninety patients with atrophic ARMD entered the study and were assigned randomly to 1 of 3 groups. Patients in group 1 received 10 mg lutein; in group 2, 10 mg lutein in combination with vitamins, minerals, and antioxidants; and in group 3, maltodextrin placebo. Changes in macular MPOD over time were evaluated. Characteristics potentially influencing MPOD included age, weight (body mass index), initial baseline values of macular pigment, and combining xanthophylls with other nutrients.

RESULTS

MPOD increased with supplementation and declined slightly without supplementation (regression slopes not equal to zero in supplemented groups, P < 0.02). The highest increases in MPOD over time occurred in patients with lower baseline values of MPOD. Statistically significant increases in MPOD density were observed in the lutein group for patients with baseline MPOD <or=0.3 optical density units and up to 0.2 optical density units in the lutein plus antioxidant group. Further analysis found that none of the subjects' eyes in the lowest quartile of baseline MPOD were in the lowest quartile for change in MPOD.

CONCLUSION

Noteworthy is the observation that those individuals with lowest MPOD, and in greatest need of supplementation, were also most likely to benefit from either the lutein or the lutein plus antioxidant supplementation. For those individuals who responded to supplementation, their macular pigment optical density had not ceased to increase at 12 months' duration of supplementation. The inference is that if a deficiency in macular pigment optical density is accurately diagnosed, effective interventions should be able to re-establish this prophylactic barrier.

Beneficial long-term effects of combined oral/topical antioxidant treatment with the carotenoids lutein and zeaxanthin on human skin: a double-blind, placebo-controlled study

BACKGROUND

The skin is exposed to numerous environmental assaults that can lead to premature aging. Of these agents, perhaps none is more ubiquitous than the ultraviolet (UV) wavelengths of sunlight. The primary immediate defense against environmental skin damage is the antioxidant capacity of the skin. However, this defense system can be compromised by moderate exposure to UV light. Therefore, bolstering the antioxidant defense system of the skin is a potentially important strategy for reducing environmentally induced skin damage.

AIM OF THE STUDY

This clinical trial was designed to study the efficacy of lutein and zeaxanthin, two potentially important antioxidants found naturally in the skin, upon five skin physiology parameters (surface lipids, hydration, photoprotective activity, skin elasticity and skin lipid peroxidation - malondialdehyde) of human subjects. These xanthophyllic carotenoids were administered either orally, topically, or in combination (both oral and topical routes).

RESULTS

The results obtained indicate that the combined oral and topical administration of lutein and zeaxanthin provides the highest degree of antioxidant protection. However, oral and topical administration of these antioxidants individually also provides significant activity in the skin. In addition, oral administration of lutein may provide better protection than that afforded by topical application of this antioxidant when measured by changes in lipid peroxidation and photoprotective activity in the skin following UV light irradiation.

Lutein supplementation in retinitis pigmentosa: PC-based vision assessment in a randomized double-masked placebo-controlled clinical trial [NCT00029289]

Background

There is no generally accepted medical or surgical treatment to stop the progressive course of retinitis pigmentosa. Previous studies have suggested lutein as a potential treatment with positive effects on macular pigment density. The objective of this study was to examine the effect of lutein supplementation on preservation of visual function in patients with retinitis pigmentosa (RP)

Methods

In a double-masked randomized placebo-controlled phase I/II clinical trial with a cross-over design, 34 adult patients with RP were randomized to two groups. One group, consisted of 16 participants, received lutein supplementation (10 mg/d for 12 wks followed by 30 mg/d) for the first 24 weeks and then placebo for the following 24 weeks, while the other group included 18 participants for whom placebo (24 weeks) was administered prior to lutein. Visual acuity, contrast sensitivity, and central visual field were measured at different illumination levels at baseline and every week using a PC-based test at home.

Results

For visual acuity (VA) at normal illumination level, treatment with lutein reduced logMAR, i.e. improved VA, but this effect was not statistically significant. The changes in normal (100%), low (4%), and very low (0.1%) illumination log CS were not statistically significant (p-values: 0.34, 0.23, and 0.32, respectively). Lutein had a statistically significant effect on visual field (p-value: 0.038) and this effect increased in the model assuming a 6-week delay in effect of lutein. Comparing the development of vision measures against the natural loss expected to occur over the course of 48 weeks, most measures showed reduced decline, and these reductions were significant for normal illumination VA and CS.

Conclusion

These results suggest that lutein supplementation improves visual field and also might improve visual acuity slightly, although these results should be interpreted cautiously. As a combined phase I and II clinical trial, this study demonstrated the efficacy and safety of lutein supplementation.

Treatment of nonexudative (dry) age-related macular degeneration

PURPOSE OF REVIEW

The purpose of this report is to review the recent literature and summarize currently available and potential new treatment options for nonexudative age-related macular degeneration.

RECENT FINDINGS

High-dose vitamin supplementation may have some associated systemic toxicity. It is important to check that the patient is taking beta-carotene and not vitamin A as retinal acetate or palmitate, which have been associated with osteoporosis and hepatotoxicity. High-dose vitamins E and C may be associated with cardiovascular disease. Decreasing inflammation by lowering systemic cardiac C-reactive protein, fibrinogen and cholesterol may be important, especially in light of recent epidemiologic and genetic data. The results of randomized trials of laser treatment for drusen and rheopheresis should be available during 2006. Treatment with these modalities before the results of the trials are evaluated should be avoided.

SUMMARY

The holy grail of therapy for age-related macular degeneration is to avoid the development of choroidal neovascularization. High-dose vitamin supplementation should be used only in those in whom it is indicated and inflammatory parameters including highly sensitive C-reactive protein, fibrinogen and cholesterol should be stabilized because there are data associating these parameters with age-related macular degeneration and also with cardiovascular disease.

Carotenoid actions and their relation to health and disease

Based on extensive epidemiological observation, fruits and vegetables that are a rich source of carotenoids are thought to provide health benefits by decreasing the risk of various diseases, particularly certain cancers and eye diseases. The carotenoids that have been most studied in this regard are beta-carotene, lycopene, lutein and zeaxanthin. In part, the beneficial effects of carotenoids are thought to be due to their role as antioxidants. beta-Carotene may have added benefits due its ability to be converted to vitamin A. Additionally, lutein and zeaxanthin may be protective in eye disease because they absorb damaging blue light that enters the eye. Food sources of these compounds include a variety of fruits and vegetables, although the primary sources of lycopene are tomato and tomato products. Additionally, egg yolk is a highly bioavailable source of lutein and zeaxanthin. These carotenoids are available in supplement form. However, intervention trials with large doses of beta-carotene found an adverse effect on the incidence of lung cancer in smokers and workers exposed to asbestos. Until the efficacy and safety of taking supplements containing these nutrients can be determined, current dietary recommendations of diets high in fruits and vegetables are advised.

Efficiency of a few retinoids and carotenoids in vivo in controlling benzo[a]pyrene-induced forestomach tumour in female Swiss mice

The anticarcinogenic effect of vitamin A2 (dehydroretinol and 3-hydroxyretinol) compounds was studied and compared with that of vitamin A1 (retinoic acid, retinol and retinal) and carotenoids (lutein and beta-carotene) in the benzo[a]pyrene (B(a)P)-induced forestomach tumour model of female Swiss mice in vivo. Tumour growth and gross tumour incidence observed after the administration of B(a)P (eight doses of 1 mg, twice weekly for 4 weeks) and retinoids/carotenoids (2.5 and 4.7 microm per animal per d, 2 weeks before, during and 2 weeks after B(a)P) showed that the groups supplemented with lutein and 3-hydroxyretinol produced the best results in inhibiting tumour growth and had low tumour incidence compared with the control group given B(a)P only (P<0.05). Weights recorded after the different treatments showed that the beta-carotene-supplemented group exhibited maximum weight gain, followed by retinal, retinol, retinoic acid, lutein, dehydroretinol and 3-hydroxyretinol. These results indicate that the anticarcinogenicity of the compounds is not related to the vitamin A biopotencies. Vitamin A2 compounds having half the biopotency of the vitamin A1 compounds were seen to be anticarcinogenic. Again, among the carotenoids, lutein, having 50 % less biopotency, showed more significant results than beta-carotene. Thus it is imperative to conclude that the low animal growth achieved with these compounds has a correlation with the highest suppression of tumour occurrence in the present experiment. Therefore, the daily consumption of foods having high content of lutein and vitamin A2 should be given due importance and weight in further studies.

AMD and micronutrient antioxidants

Age-related maculopathy (ARM) is a common clinical entity. The late-stage manifestations of ARM, which are known as age-related macular degeneration (AMD), have devastating consequences for vision. Various risk factors have been identified in the development of the condition, which are consistent with the premise that oxidative stress plays an important role in its pathogenesis. Thus, the possibility that antioxidant balance can be manipulated through diet or supplementation has created much interest. Associations between diet and nutrition and the clinical features of ARM have been described. Scrutiny of the literature shows consistency in the report of notable reductions in serum micronutrients in wet AMD, however, the evidence for causation is still circumstantial. In this comprehensive review of the clinical literature, we have assessed the evidence for a link between diet and nutrition as risk factors for the development of ARM and AMD. All published case control, population-based, and interventional studies on ARM were examined. Although initial support appeared to be moderate and somewhat contradictory, the evidence that lifetime oxidative stress plays an important role in the development of ARM is now compelling. The positive outcomes in the Age-Related Eye Diseases Study, a major controlled clinical trial, have given hope that modulation of the antioxidant balance through supplementation can help prevent progression of ARM to AMD.

Low doses of beta-carotene and lutein inhibit AOM-induced rat colonic ACF formation but high doses augment ACF incidence

Epidemiological studies suggest that carotenoids such as beta-carotene and lutein play an important role in reducing the risk for several cancers. However, in colon cancer there is ambiguity with regard to the role of these compounds in that both preventive effects and tumor promotion have been observed. In the present study we observed that male F344 rats were able to tolerate up to 2,500 ppm of beta-carotene as well as of lutein. We have then assessed the chemopreventive efficacy of beta-carotene and lutein at dose levels of approximately 4 and 8% of the 2,500 ppm tolerated dose (TD) and also approximately 40 and 80% of the TD on azoxymethane (AOM)-induced colon carcinogenesis, using aberrant crypt foci (ACF) as a surrogate biomarker for colon cancer. Throughout the experiments, 5-week-old male F344 rats were fed the control diet (modified AIN-76A) or experimental diets containing 100 or 200 ppm (approximately 4 or 8% of the 2,500 ppm TD), or 1,000 or 2,000 ppm ( approximately 40 or 80% of the 2,500 ppm TD) of beta-carotene and lutein (n=10 rats/group). After 2 weeks on the experimental or control diets, all animals were injected with AOM (15 mg/kg body wt., once weekly for 2 weeks). At 14 weeks of age, all rats were killed, and their colons were evaluated for ACF. Administration of 100 or 200 ppm of beta-carotene inhibited AOM-induced total colonic ACF formation by 24% (p<0.01) and 36% (p<0.001), respectively, whereas lutein at 200 ppm produced a 27% inhibition (p<0.01) yet had no significant effect at the 100 ppm dose level. Surprisingly, administration of 1,000 or 2,000 ppm of beta-carotene and lutein increased colonic ACF formation in a dose-dependent manner, i.e., to 124% and 144% for the former and 110% and 159% for the latter. These results clearly suggest that further studies are warranted to determine whether the increase in ACF incidence by high doses of beta-carotene and lutein will also lead to an increase in tumor outcome. Taken together these data indicate that the chemopreventive activity of beta-carotene and lutein against colon carcinogenesis depends on the dose level.

Lutein and Zeaxanthin and Their Potential Roles in Disease Prevention

Lutein and zeaxanthin are xanthophyll carotenoids found particularly in dark-green leafy vegetables and in egg yolks. They are widely distributed in tissues and are the principal carotenoids in the eye lens and macular region of the retina. Epidemiologic studies indicating an inverse relationship between xanthophyll intake or status and both cataract and age-related macular degeneration suggest these compounds can play a protective role in the eye. Some observational studies have also shown these xanthophylls may help reduce the risk of certain types of cancer, particularly those of the breast and lung. Emerging studies suggest as well a potential contribution of lutein and zeaxanthin to the prevention of heart disease and stroke. Even as the evidence for a role of lutein and zeaxanthin in disease prevention continues to evolve, particularly from human studies directed to their bioavailability, metabolism, and dose-response relationships with intermediary biomarkers and clinical outcomes, it is worth noting that recommendations to consume foods rich in xanthophylls are consistent with current dietary guidelines.