High serum level of lutein may be protective against early atherosclerosis: the Beijing atherosclerosis study

Microalgae as a Source of Valuable Phenolic Compounds and Carotenoids

Microalgae are photosynthetic, eukaryotic organisms that are widely used in the industry as cell factories to produce valuable substances, such as fatty acids (polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), sterols (sitosterol), recombinant therapeutic proteins, carbohydrates, vitamins, phenolic compounds (gallic acid, quercetin), and pigments (β-carotene, astaxanthin, lutein). Phenolic compounds and carotenoids, including those extracted from microalgae, possess beneficial bioactivities such as antioxidant capacity, antimicrobial and immunomodulatory activities, and direct health-promoting effects, which may alleviate oxidative stress and age-related diseases, including cardiovascular diseases or diabetes. The production of valuable microalgal metabolites can be modified by using abiotic stressors, such as light, salinity, nutrient availability, and xenobiotics (for instance, phytohormones).

Nanoscale Delivery Systems of Lutein: An Updated Review from a Pharmaceutical Perspective

Carotenoids are natural lipid-soluble pigments that produce yellow to red colors in plants as well as providing bright coloration in vegetables and fruits. Lutein belongs to the xanthophyll subgroup of the carotenoid family, which plays an essential role in photosynthesis and photoprotection in nature. In the human body, lutein, together with its isomer zeaxanthin and its metabolite meso-zeaxanthin, accumulates in the macula of the eye retina, which is responsible for central, high-resolution, and color vision. As a bioactive phytochemical, lutein has essential physiological functions, providing photoprotection against damaging blue light, along with the neutralization of oxidants and the preservation of the structural and functional integrity of cellular membranes. As a potent antioxidant and anti-inflammatory agent, lutein unfortunately has a low bioavailability because of its lipophilicity and a low stability as a result of its conjugated double bonds. In order to enhance lutein stability and bioavailability and achieve its controlled delivery to a target, nanoscale delivery systems, which have great potential for the delivery of bioactive compounds, are starting to be employed. The current review highlights the advantages and innovations associated with incorporating lutein within promising nanoscale delivery systems, such as liposomes, nanoemulsions, polymer nanoparticles, and polymer–lipid hybrid nanoparticles, as well as their unique physiochemical properties.

Role of Carotenoids in Cardiovascular Disease

Carotenes are fat-soluble pigments found in a variety of foods, the majority of which are fruits and vegetables. They may have antioxidant biological properties due to their chemical makeup and relationship to cellular membranes. And over 700 carotenoids have been found, with—carotene, lutein, lycopene, and zeaxanthin is the most significant antioxidant food pigments. Their capacity to absorb lipid peroxides, reactive oxygen species (ROS) and nitrous oxide is likely linked to their anti-oxidative properties (NO). The daily requirements for carotenoids are also discussed in this chapter. Heart disease is still a prominent source of sickness and mortality in modern societies. Natural antioxidants contained in fruits and vegetables, such as lycopene, a-carotene, and B-carotene, may help prevent CVD by reducing oxidative stress, which is a major factor in the disease’s progression. Numerous epidemiological studies have backed up the idea that antioxidants might be utilized to prevent and perhaps treat cardiovascular illnesses at a low cost. Supplements containing carotenoids are also available, and their effectiveness has been proven. This article provides an overview of carotenoids’ chemistry, including uptake, transport, availability, metabolism, and antioxidant activity, including its involvement with disease prevention, notably cardiovascular disease.

Multivariate Analysis Reveals That Unsubstituted β-Ring and C8-Keto Structures Are Important Factors for Anti-Inflammatory Activity of Carotenoids

Carotenoids are natural lipophilic pigments with substantial health benefits. Numerous studies have demonstrated the anti-inflammatory activities of carotenoids, especially toward lipopolysaccharide-induced inflammatory responses. As such, there are few reports on the evaluation and comparison of the anti-inflammatory activities of carotenoids against inflammation induced by other stimuli. In this study, we used pathogen-associated molecular patterns, proinflammatory cytokines, degenerated proteins, and chemical irritants as inflammatory inducers to evaluate the anti-inflammatory activities of eight different carotenoids. Each carotenoid showed characteristic anti-inflammatory activities; thus, we conducted a multivariate analysis to clarify the differences among them. Unsubstituted β-ring (i.e., provitamin A) and C8-keto structures of carotenoids were found to be crucial for their inhibitory effects on the activation of nuclear factor-kappa B and interferon regulatory factors, respectively. Furthermore, we found that β-carotene and echinenone treatment increased intracellular retinoid levels in monocytes and that the retinoids showed the similar activities to β-carotene and echinenone. Taken together, the intake of both provitamin A and C8-keto carotenoids (e.g., siphonaxanthin and fucoxanthin) might be effective in improving the inflammatory status of individuals. A multivariate analysis of anti-inflammatory activities is a useful method for characterizing anti-inflammatory compounds.

Lutein as a Modulator of Oxidative Stress-Mediated Inflammatory Diseases

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

Lutein attenuates angiotensin II- induced cardiac remodeling by inhibiting AP-1/IL-11 signaling

RATIONALE

Oxidative stress plays a critical role in the development of cardiac remodeling and heart failure. Lutein, the predominant nonvitamin A carotenoid, has been shown to have profound effects on oxidative stress. However, the effect of lutein on angiotensin II (Ang II)-induced cardiac remodeling and heart failure remains unknown.

OBJECTIVE

The aim of this study was to determine whether lutein is involved in cardiac remodeling and to elucidate the underlying molecular mechanisms.

METHODS AND RESULTS

In vitro experiments with isolated neonatal rat cardiomyocytes (NRCMs) and cardiac fibroblasts (CFs) revealed that lutein significantly attenuated Ang II-induced collagen expression in CFs, and cardiomyocyte hypertrophy. The Ang II-induced increases in superoxide generation, inflammation and apoptosis in cultured CFs were strikingly prevented by lutein. In vivo, fibrosis, hypertrophic cardiomyocyte and superoxide generation were analyzed, and lutein was demonstrated to confer resistance to Ang II-induced cardiac remodeling in mice. Mechanistically, RNA sequencing revealed that interleukin-11 (IL-11) expression was significantly upregulated in mouse hearts in response to Ang II infusion and was significantly suppressed in the hearts of lutein-treated mice. Furthermore, IL-11 overexpression blocked the effects of lutein on fibrosis and oxidative stress in CFs and impaired the protective effect of lutein on cardiac remodeling. Notably, we discovered that lutein could reduce Ang II-induced IL-11 expression, at least partly through the regulation of activator protein (AP)-1 expression and activity.

CONCLUSIONS

Lutein has potential as a treatment for cardiac remodeling and heart failure via the suppression of IL-11 expression.

Long non-coding RNA CASC9/microRNA-590-3p axis participates in lutein-mediated suppression of breast cancer cell proliferation

Previous studies have shown that lutein can inhibit the proliferation of breast cancer cells. However, the mechanism of lutein inhibiting the proliferation of breast cancer cells remains unclear. The present study aimed to determine whether the long non-coding RNA (lncRNA) Cancer Susceptibility 9 (CASC9)/microRNA (miR)-590-3p axis participates in the antiproliferative effects of lutein via lncRNA microarray hybridization, reverse transcription-quantitative PCR, dual-luciferase reporter and MTT assays. The results demonstrated that CASC9 was the most significantly downregulated lncRNA in MCF7 cells treated with lutein. miR-590-3p was identified as the target of CASC9. In addition, lutein downregulated CASC9 expression and upregulated miR-590-3p expression in dose- and time-dependent manners, respectively. CASC9 knockdown or overexpression of miR-590-3p inhibited the proliferation of breast cancer cells. Notably, simultaneous transfection with miR-590-3p mimics and CASC9 small interfering RNA increased the potency of lutein in inhibiting the proliferation of breast cancer cells. Taken together, these results suggest that the CASC9/miR-590-3p axis participates in the antiproliferative effects of lutein on breast cancer.

Date Palm Pollen Extract Avert Doxorubicin-Induced Cardiomyopathy Fibrosis and Associated Oxidative/Nitrosative Stress, Inflammatory Cascade, and Apoptosis-Targeting Bax/Bcl-2 and Caspase-3 Signaling Pathways

Simple Summary

The use of date palm pollen ethanolic extract (DPPE) is a conventional approach in improving the side-effects induced by Doxorubicin (DOX).DPPE mitigated DOX-induced body and heart weight changes and ameliorated DOX-induced elevated cardiac injury markers. In addition, serum cardiac troponin I concentrations (cTnI), troponin T (cTnT), and N-terminal NBP and cytosolic (Ca⁺²) were amplified by alleviating the inflammatory and oxidative injury markers and decreasing histopathological lesions severity. DPPE decreased DOX-induced heart injuries by mitigating inflammation, fibrosis, and apoptosis through its antioxidant effect. To reduce DOX-induced oxidative stress injuries and other detrimental effects, a combined treatment of DPPE is advocated.

Abstract

Doxorubicin (DOX) has a potent antineoplastic efficacy and is considered a cornerstone of chemotherapy. However, it causes several dose-dependent cardiotoxic results, which has substantially restricted its clinical application. This study was intended to explore the potential ameliorative effect of date palm pollen ethanolic extract (DPPE) against DOX-induced cardiotoxicity and the mechanisms underlying it. Forty male Wistar albino rats were equally allocated into Control (CTR), DPPE (500 mg/kg bw for 4 weeks), DOX (2.5 mg/kg bw, intraperitoneally six times over 2 weeks), and DPPE + DOX-treated groups. Pre-coadministration of DPPE with DOX partially ameliorated DOX-induced cardiotoxicity as DPPE improved DOX-induced body and heart weight changes and mitigated the elevated cardiac injury markers activities of serum aminotransferases, lactate dehydrogenase, creatine kinase, and creatine kinase-cardiac type isoenzyme. Additionally, the concentration of serum cardiac troponin I (cTnI), troponin T (cTnT), N-terminal pro-brain natriuretic peptide (NT-pro BNP), and cytosolic calcium (Ca⁺²) were amplified. DPPE also alleviated nitrosative status (nitric oxide) in DOX-treated animals, lipid peroxidation and antioxidant molecules as glutathione content, and glutathione peroxidase, catalase, and superoxide dismutase activities and inflammatory markers levels; NF-κB p65, TNF-α, IL-1β, and IL-6. As well, it ameliorated the severity of histopathological lesions, histomorphometric alteration and improved the immune-staining of the pro-fibrotic (TGF-β1), pro-apoptotic (caspase-3 and Bax), and anti-apoptotic (Bcl-2) proteins in cardiac tissues. Collectively, pre-coadministration of DPPE partially mitigated DOX-induced cardiac injuries via its antioxidant, anti-inflammatory, anti-fibrotic, and anti-apoptotic potential.

Chili Pepper Carotenoids: Nutraceutical Properties and Mechanisms of Action

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

A Brief Overview of Dietary Zeaxanthin Occurrence and Bioaccessibility

As it exhibits no provitamin A activity, the dietary intake of zeaxanthin is not considered essential. However, its contribution to ocular health has long been acknowledged. Numerous publications emphasize the importance of zeaxanthin alongside lutein in ocular diseases such as cataracts and age-related macular degeneration which constitute an important health concern, especially among the elderly. Considering that the average dietary ratio of lutein to zeaxanthin favors the first, more bioaccessible food sources of zeaxanthin that can hinder the development and progression of the above-mentioned disorders are of great interest. In this paper, a brief overview of the more recent state of knowledge as regards dietary sources together with their respective zeaxanthin bioaccessibility assessed through a standardized in vitro digestion method was provided.

5-cis-, Trans- and Total Lycopene Plasma Concentrations Inversely Relate to Atherosclerotic Plaque Burden in Newly Diagnosed Type 2 Diabetes Subjects

Diabetic subjects are at increased risk of cardiovascular disease. Atherosclerosis, the common soil of most of the cardiovascular complications, is more prevalent and extensive in this population due not only to hyperglycemia, insulin resistance, and dyslipidemia, but also to inflammation and oxidative stress. Lycopenes are bioactive compounds with antioxidant and anti-inflammatory activities mostly supplied by tomato and tomato byproducts. We investigated the association between circulating lycopenes and carotid plaque burden in diabetic patients, in a cross-sectional study in 105 newly diagnosed diabetic subjects. Atheroma plaque (wall thickness ≥ 1.5 mm), number of plaques, and plaque burden (sum of maximum heights of all plaques) were assessed by sonographic evaluation of carotid arteries. Plasma lycopenes (5-cis-, 9-cis-, 13-cis-, and trans-lycopene) were quantified by high performance liquid chromatography–mass spectrometry HPLC-MS. Atheroma plaque was observed in 75 participants, from which 38 presented one plaque and 37 two or more carotid plaques. No differences were observed in the plasmatic concentrations of lycopenes between subjects with and without atherosclerotic plaque presence. However, plaque burden was inversely associated with 5-cis-lycopene, all cis-lycopene isomers, trans-lycopene, and total lycopene isomers (all, p < 0.05). High plasma levels of lycopenes inversely relate to atherosclerotic burden. We provide novel evidence that suggests that the consumption of compounds found in tomato and tomato byproducts might be beneficial for the prevention of atherosclerosis.

Effects of lutein supplementation on inflammatory biomarkers and metabolic risk factors in adults with central obesity: study protocol for a randomised controlled study

Background

The prevalence of central obesity is constantly increasing, and visceral fat is associated with increased production of inflammatory factors and metabolic risk factors. Lutein might retard the development of metabolic disease through its antioxidant and anti-inflammatory properties. Furthermore, epidemiological studies have associated higher dietary intake and serum levels of lutein with decreased adiposity. However, few randomised controlled trials have shown the effects of lutein supplementation on inflammatory biomarkers and metabolic risk factors, especially in adults with central obesity.

Methods

This study will be conducted as a double-blind, parallel placebo-controlled clinical trial in which 120 people who have central obesity, are 18 to 60 years old and are willing to provide informed consent will be randomly assigned to the intervention or placebo group in a 1:1 ratio according to sex, age and waist circumference. The intervention group will receive 10 mg daily lutein supplementation for 12 weeks to explore the effect of lutein supplementation on serum lutein, glycaemic and lipid profiles, inflammatory factors and body composition. Two populations (intention-to-treat population and per-protocol population) will be used in the data analyses.

Discussion

Our findings from this trial will contribute to the knowledge of the association between lutein supplementation and inflammatory biomarkers and metabolic risk factors in people with central obesity and will offer a possibility for the prevention of inflammatory diseases.

Trial registration

Chinese Clinical Trial Registry: ChiCTR1800018098. Registered on 30 August 2018.

Mechanistic insights into the effect of lutein on atherosclerosis, vascular dysfunction, and related risk factors: A systematic review of in vivo, ex vivo and in vitro studies

Lutein is an essential carotenoid commonly consumed in the diet; however, its dietary intake does not usually reach the minimum recommended intake to decrease the incidence of chronic diseases. Experimental and epidemiological evidence suggests an anti-atherosclerotic effect for lutein-rich foods or lutein supplementation. This systematic review aimed to assess the mechanistic pathways of lutein in the prevention of atherosclerosis. Electronic databases, including PubMed, SCOPUS, ProQuest, Embase, and Google Scholar were searched to May 2019. Original studies published in English-language journals that investigated the effects of lutein on atherosclerosis and related risk factors, including lipid profile, hemodynamic, glycemic and inflammatory measurements, and endothelial function indices, were considered. Two reviewers independently extracted data on study characteristics, methods and outcomes. The review protocol has been registered at PROSPERO database of Systematic Reviews (registration number: CRD42019121381). A total of 5818 articles were found in the first phase of the search; from these, 19 met the inclusion criteria: 3 in vitro, 1 ex vivo, 11 animal, and 4 human studies. Nine of ten studies showed positive effects of lutein on endothelial function by reducing blood pressure, arterial thickness, monocyte migration, and vascular smooth muscle cell migration. Twelve studies examined the anti-inflammatory properties of lutein and found a significant decrease in proinflammatory cytokines. Although few studies investigated the anti-hyperlipidemic effects of lutein, three animal studies and one clinical trial found a beneficial effect of lutein on lipid profile. Evidence supports positive effects of lutein on atherosclerosis development and some common risk factors of atherosclerosis, including inflammation and endothelial dysfunction. Further studies focused on the effects of lutein on hyperglycemia, lipid profile, blood pressure and coagulation are required.

Zeaxanthin: Metabolism, Properties, and Antioxidant Protection of Eyes, Heart, Liver, and Skin

Zeaxanthin, a non-provitamin A carotenoid that belongs to the xanthophyll family, has been less studied than its isomer lutein. However, zeaxanthin has also been shown to have a number of beneficial effects for human health due to its ability to quench free radicals, exert antioxidant effects, as well as decrease inflammation. It is the purpose of this review to discuss the metabolism of zeaxanthin, including digestion, absorption, transport, and uptake by tissues, as well as the dietary or other factors which affect zeaxanthin bioavailability. In addition, this review also focuses on specific effects of this carotenoid on eye, skin, liver, and cardiovascular health. Data derived from human interventions, animal models of research, and in vitro and cell studies are discussed in this review.

Higher dietary and serum carotenoid levels are associated with lower carotid intima-media thickness in middle-aged and elderly people

Several studies have suggested that higher carotenoid levels may be beneficial for atherosclerosis patients, but few studies have examined this relationship in the Chinese population. This cross-sectional study examined the association between the levels of carotenoids in diet and serum and carotid intima-media thickness (IMT) in Chinese adults aged 50-75 years in Guangzhou, China. Dietary intake was assessed using a FFQ. HPLC was used to assay the serum concentrations of α-carotene, β-carotene, lutein+zeaxanthin, β-cryptoxanthin and lycopene. The IMT at the common carotid artery (CCA) and bifurcation of the carotid artery was measured by B-mode ultrasound. A total of 3707 and 2947 participants were included in the analyses of dietary and serum carotenoids. After adjustment for demographic, socio-economic and lifestyle factors, all the serum carotenoids levels except lycopene were found to be inversely associated with the IMT at the CCA and bifurcation (P trend<0·001 to 0·013) in both men and women. The absolute mean differences in the IMT between the subjects in the extreme quartiles of serum carotenoid levels were 0·034 mm (α-carotene), 0·037 mm (β-carotene), 0·032 mm (lutein+zeaxanthin), 0·030 mm (β-cryptoxanthin), 0·015 mm (lycopene) and 0·035 mm (total carotenoids) at the CCA; the corresponding values were 0·025, 0·053 0·043, 0·050, 0·011 and 0·042 mm at the bifurcation. The favourable associations were also observed between dietary carotenoids (except lycopene) and the CCA IMT. In conclusion, elevated carotenoid levels in diet and serum are associated with lower carotid IMT values (particular at the CCA) in Chinese adults.

Association of serum lutein and zeaxanthin with quantitative measures of retinal vascular parameters

To evaluate the association between serum carotenoids and quantitative measures of retinal vasculature in elderly Singapore Chinese subjects. The following details were collected in 128 healthy subjects: sociodemographics, lifestyle information, medical and drug history, and anthropometric measurements. Serum concentrations of carotenoids were estimated in fasting venous blood using high performance liquid chromatography. Retinal vascular parameters were quantitatively measured from retinal photographs using a computer-assisted program (Singapore I Vessel Assessment). The mean age of the population was 54.1 years (range 40 to 81 years). In multiple linear regression analysis, per SD decrease in retinal arteriolar caliber [β = 0.045 (0.003 to 0.086), p = 0.036], per SD increase in retinal venular caliber [β = -0.045 (-0.086 to -0.003), p = 0.036] and per SD increase in arteriolar branching angle [β = -0.039 (-0.072 to -0.006), p = 0.021] were associated with decreased serum lutein. Per SD increase in retinal venular tortuosity [β = -0.0075 (-0.0145 to -0.0004), p = 0.039] and per SD increase in arteriolar branching angle (β = -0.0073 [-0.0142 to -0.0059], p = 0.041) were associated with decreased serum zeaxanthin. None of the other carotenoids demonstrated meaningful relationship with quantitative measures of retinal vasculature. Lower levels of lutein and zeaxanthin demonstrated significant relationship with adverse quantitative measures of retinal vasculature in elderly healthy subjects.

NrF2/ARE and NF-κB pathway regulation may be the mechanism for lutein inhibition of human breast cancer cell

Aim: Though lutein can inhibit cancer cell proliferation via alleviating oxidative injury, the molecular mechanisms of lutein involvement in the NrF2/antioxidant response element (ARE) and NF-κB pathways remain poorly understood. Materials & methods: MTT, flow cytometry, quantitative real-time PCR (qRT-PCR) and western blot assays were performed. Results: After treatment with lutein, breast cancer cell proliferation was significantly decreased in a dose-dependent manner. Lutein induced nuclear translocation and protein expression of NrF2, improved the expression of cellular antioxidant enzymes and attenuated reactive oxygen species levels. Moreover, lutein treatment decreased NF-κB signaling pathway related NF-κB p65 protein expression. Conclusion: The effect of lutein antiproliferation was mediated by activation of the NrF2/ARE pathway, and blocking of the NF-κB signaling pathway.

Lutein exerts anti-inflammatory effects in patients with coronary artery disease

BACKGROUND AND AIMS

Many coronary artery disease (CAD) patients exhibit chronic low-grade inflammation. Carotenoids are anti-oxidants with potential anti-inflammatory properties. Here, we first assessed relationships between interleukin (IL)-6 and individual carotenoids in plasma from CAD patients. Based on the results, we proceeded to assess anti-inflammatory effects of one carotenoid, lutein, in peripheral blood mononuclear cells (PBMCs) from CAD patients.

METHODS

Lutein + zeaxanthin (isomers with lutein being dominant), β-cryptoxanthin, lycopene, α- and β-carotene and IL-6 were measured in plasma from 134 patients with stable angina (SA) and 59 patients with acute coronary syndrome. In 42 patients, plasma measurements were also performed 3 months after coronary intervention. PBMCs from SA patients were pre-treated with lutein (1, 5 and 25 μM) for 24 h followed by 24 h incubation ± lipopolysaccharide (LPS). Cell pellets were collected for IL-6, IL-1β and TNF mRNA and intracellular lutein. Cytokine secretion was measured in cell media.

RESULTS

Only lutein + zeaxanthin were inversely correlated with IL-6 in SA patients at baseline (r = -0.366, p < 0.001) and follow-up (r = -0.546, p < 0.001). Ex vivo, lutein was taken up by PBMCs from SA patients in a dose- and time-dependent manner. Pre-treatment with lutein dose-dependently lowered LPS-induced secretion of IL-6, IL-1β (p < 0.01) and TNF (p < 0.05), and also reduced IL-6, IL-1β and TNF mRNA expression (p < 0.05).

CONCLUSIONS

Clinical findings highlighted the inverse association between lutein and IL-6 in CAD patients. Anti-inflammatory effects of lutein in PBMCs from CAD patients were consolidated in ex vivo experiments. Taken together, these results show that lutein has the potential to play a role in resolution of chronic inflammation in CAD patients.

One-year daily consumption of buttermilk drink containing lutein-enriched egg-yolks does not affect endothelial function in fasting and postprandial state

Previous results have shown that one-year daily consumption of a lutein-enriched egg yolk containing dairy drink did not significantly affect fasting serum lipid and lipoprotein concentrations in adults with early signs of macular degeneration. The current study further substantiates these findings with parameters reflecting endothelial function. Additionally, we extend our observations from the fasting to the postprandial situation. Subjects participated in a 1-y randomized placebo-controlled dietary intervention trial. 52 subjects were included in the active (Egg) group and 49 in the control (Con) group. Changes in postprandial biochemistry (triacylglycerol (TAG), glucose and non-esterified fatty acids (NEFA)) following a mixed meal and flow-mediated dilation (FMD) analyses were evaluated at the start and after one year intervention. Postprandial glycemic and lipemic responses before the intervention as well as the differences in postprandial responses after one-year intervention were comparable between the Egg and the Con group. Fasting FMD was comparable between the groups before the intervention started and at the end of intervention. Additionally, the change in FMD following a mixed meal was comparable between the groups. To conclude, one-year consumption of a lutein-enriched egg yolk incorporated in a dairy drink has no effect on postprandial lipid and glucose metabolism or endothelial function.

The effects of lutein on cardiometabolic health across the life course: a systematic review and meta-analysis

BACKGROUND

The antioxidant lutein is suggested as being beneficial to cardiometabolic health because of its protective effect against oxidative stress, but evidence has not systematically been evaluated.

OBJECTIVE

We aimed to evaluate systematically the effects of lutein (intake or concentrations) on cardiometabolic outcomes in different life stages.

DESIGN

This is a systematic review with meta-analysis of literature published in MEDLINE, Embase, Cochrane Central, Web of Science, PubMed, and Google Scholar up to August 2014. Included were trials and cohort, case-control, and cross-sectional studies in which the association between lutein concentrations, dietary intake, or supplements and cardiometabolic outcomes was reported. Two independent investigators reviewed the articles.

RESULTS

Seventy-one relevant articles were identified that included a total of 387,569 participants. Only 1 article investigated the effects of lutein during pregnancy, and 3 studied lutein in children. Furthermore, 31 longitudinal, 33 cross-sectional, and 3 intervention studies were conducted in adults. Meta-analysis showed a lower risk of coronary heart disease (pooled RR: 0.88; 95% CI: 0.80, 0.98) and stroke (pooled RR: 0.82; 95% CI: 0.72, 0.93) for the highest compared with the lowest tertile of lutein blood concentration or intake. There was no significant association with type 2 diabetes mellitus (pooled RR: 0.97; 95% CI: 0.77, 1.22), but higher lutein was associated with a lower risk of metabolic syndrome (pooled RR: 0.75; 95% CI: 0.60, 0.92) for the highest compared with the lowest tertile. The literature on risk factors for cardiometabolic diseases showed that lutein might be beneficial for atherosclerosis and inflammatory markers, but there were inconsistent associations with blood pressure, adiposity, insulin resistance, and blood lipids.

CONCLUSIONS

Our findings suggest that higher dietary intake and higher blood concentrations of lutein are generally associated with better cardiometabolic health. However, evidence mainly comes from observational studies in adults, whereas large-scale intervention studies and studies of lutein during pregnancy and childhood are scarce.

The association between maternal antioxidant levels in midpregnancy and preeclampsia

OBJECTIVE

We sought to determine whether midpregnancy antioxidant levels are associated with preeclampsia, overall and by timing of onset.

STUDY DESIGN

We carried out a case-control study, nested within a cohort of 5337 pregnant women in Montreal, Quebec, Canada. Blood samples obtained at 24-26 weeks were assayed for nonenzymatic antioxidant levels among cases of preeclampsia (n = 111) and unaffected controls (n = 441). We excluded women diagnosed with gestational hypertension only. We used logistic regression with the z-score of each antioxidant level as the main predictor variable for preeclampsia risk. We further stratified early-onset (<34 weeks) and late-onset preeclampsia and carried out multinomial logistic regression. Finally, we assessed associations between antioxidant biomarkers and timing of onset (in weeks) by Cox regression, with appropriate selection weights. We summed levels of correlated biomarkers (r(2) > 0.3) and log-transformed positively skewed distributions. We adjusted for body mass index, nulliparity, preexisting diabetes, hypertension, smoking, and proxies for ethnicity and socioeconomic status.

RESULTS

The odds ratios for α-tocopherol, α-tocopherol:cholesterol, lycopene, lutein, and carotenoids (sum of α-carotene, β-carotene, anhydrolutein, α-cryptoxanthin, and β-cryptoxanthin) suggested an inverse association between antioxidant levels and overall preeclampsia risk; however, only lutein was significantly associated with overall preeclampsia in adjusted models (odds ratio, 0.60; 95% confidence interval, 0.46-0.77) per SD. In multinomial logistic models, the relative risk ratio (RRR) estimates for the early-onset subgroup were farther from the null than those for the late-onset subgroup. The ratio of α-tocopherol to cholesterol and retinol were significantly associated with early- but not late-onset preeclampsia: RRRs (95% confidence intervals) for early-onset preeclampsia 0.67 (0.46-0.99) and 1.61 (1.12-2.33), respectively. Lutein was significantly associated with both early- and late-onset subtypes in adjusted models; RRRs 0.53 (0.35-0.80) and 0.62 (0.47-0.82), respectively. Survival analyses confirmed these trends.

CONCLUSION

Most antioxidants were more strongly associated with early-onset preeclampsia, suggesting that oxidative stress may play a greater role in the pathophysiology of early-onset preeclampsia. Alternatively, reverse causality may explain this pattern. Lutein was associated with both early- and late-onset preeclampsia and may be a promising nutrient to consider in preeclampsia prevention trials, if this finding is corroborated.

Lutein prevents high fat diet-induced atherosclerosis in ApoE-deficient mice by inhibiting NADPH oxidase and increasing PPAR expression

Epidemiological and experimental studies provide supportive evidence that lutein, a major carotenoid, may act as a chemopreventive agent against atherosclerosis, although the underlying molecular mechanisms are not well understood. The main aim of this study was to investigate the effects of lutein on the alleviation of atherosclerosis and its molecular mechanisms involved in oxidative stress and lipid metabolism. Male apolipoprotein E knockout mice (n = 55) were fed either a normal chow diet or a high fat diet (HFD) supplemented with or without lutein for 24 weeks. The results showed that a HFD induced atherosclerosis formation, lipid metabolism disorders and oxidative stress, but noticeable improvements were observed in the lutein treated group. Additionally, lutein supplementation reversed the decreased protein expression of aortic heme oxygenase-1 and increased the mRNA and protein expressions of aortic nicotinamide-adenine dinucleotide phosphate oxidase stimulated by a HFD. Furthermore, the decreased mRNA and protein expression levels of hepatic peroxisome proliferator-activated receptor-α, carnitine palmitoyltransferase 1A, acyl CoA oxidase 1, low density lipoprotein receptors and scavenger receptor class B type I observed in mice with atherosclerosis were markedly enhanced after treatment with lutein. Taken together, these data add new evidence supporting the anti-atherogenic properties of lutein and describing its mechanisms of action in atherosclerosis prevention, including oxidative stress and lipid metabolism improvements.

Carotenoids: potential allies of cardiovascular health?

Carotenoids are a class of natural, fat-soluble pigments found principally in plants. They have potential antioxidant biological properties because of their chemical structure and interaction with biological membranes. Epidemiologic studies supported the hypothesis that antioxidants could be used as an inexpensive means of both primary and secondary cardiovascular disease (CVD) prevention. In fact, the oxidation of low-density lipoproteins (LDL) in the vessels plays a key role in the development of atherosclerotic lesions. The resistance of LDL to oxidation is increased by high dietary antioxidant intake, so that carotenoids, as part of food patterns such as the Mediterranean diet, may have beneficial effects on cardiovascular health too. Further properties of carotenoids leading to a potential reduction of cardiovascular risk are represented by lowering of blood pressure, reduction of pro-inflammatory cytokines and markers of inflammation (such as C-reactive protein), and improvement of insulin sensitivity in muscle, liver, and adipose tissues. In addition, recent nutrigenomics studies have focused on the exceptional ability of carotenoids in modulating the expression of specific genes involved in cell metabolism. The aim of this review is to focus attention to this effect of some carotenoids to prevent CVD.

Dietary predictors of arterial stiffness in a cohort with type 1 and type 2 diabetes

OBJECTIVE

To determine the dietary predictors of central blood pressure, augmentation index and pulse wave velocity (PWV) in subjects with type 1 and type 2 diabetes.

METHODS

Participants were diagnosed with type 1 or type 2 diabetes and had PWV and/or pulse wave analysis performed. Dietary intake was measured using the Dietary Questionnaire for Epidemiological Studies Version 2 Food Frequency Questionnaire. Serum lipid species and carotenoids were measured, using liquid chromatography electrospray ionization-tandem mass spectrometry and high performance liquid chromatography, as biomarkers of dairy and vegetable intake, respectively. Associations were determined using linear regression adjusted for potential confounders.

RESULTS

PWV (n = 95) was inversely associated with reduced fat dairy intake (β = -0.01; 95% CI -0.02, -0.01; p = 0 < 0.05) in particular yoghurt consumption (β = -0.04; 95% CI -0.09, -0.01; p = 0 < 0.05) after multivariate adjustment. Total vegetable consumption was negatively associated with PWV in the whole cohort after full adjustment (β = -0.04; 95% CI -0.07, -0.01; p < 0.05). Individual lipid species, particularly those containing 14:0, 15:0, 16:0, 17:0 and 17:1 fatty acids, known to be of ruminant origin, in lysophosphatidylcholine, cholesterol ester, diacylglycerol, phosphatidylcholine, sphingomyelin and triacylglycerol classes were positively associated with intake of full fat dairy, after adjustment for multiple comparisons. However, there was no association between serum lipid species and PWV. There were no dietary predictors of central blood pressure or augmentation index after multivariate adjustment.

CONCLUSION

In this cohort of subjects with diabetes reduced fat dairy intake and vegetable consumption were inversely associated with PWV. The lack of a relationship between serum lipid species and PWV suggests that the fatty acid composition of dairy may not explain the beneficial effect.

Consuming a buttermilk drink containing lutein-enriched egg yolk daily for 1 year increased plasma lutein but did not affect serum lipid or lipoprotein concentrations in adults with early signs of age-related macular degeneration

Dietary lutein intake is postulated to interfere with the development of age-related macular degeneration (AMD). Because egg yolk-derived lutein has a high bioavailability, long-term consumption of lutein-enriched eggs might be effective in preventing AMD development, but alternatively might increase cardiovascular disease risk. Here, we report the effect of 1-y daily consumption of a buttermilk drink containing 1.5 lutein-rich egg yolks on serum lipid and lipoprotein and plasma lutein concentrations. Additionally, subgroups that could potentially benefit the most from the intervention were identified. Men and women who had early signs of AMD in at least 1 eye, but were otherwise healthy, participated in a 1-y randomized, placebo-controlled parallel intervention trial. At the start of the study, 101 participants were included: 52 in the experimental (Egg) group and 49 in the control (Con) group. Final analyses were performed with 45 participants in the Egg group and 43 participants in the Con group. As expected, the increase in plasma lutein concentrations in the Egg group was 83% higher than that in the Con group (P < 0.001). Changes in serum total, HDL, and LDL cholesterol, as well as the ratio of total cholesterol to HDL cholesterol, were not different between the 2 groups. Interestingly, participants classified as cholesterol absorbers had higher serum HDL cholesterol concentrations than participants classified as cholesterol synthesizers or participants with average campesterol-to-lathosterol ratios (P < 0.05) at baseline. In addition, cholesterol absorbers had a 229% higher increase in plasma lutein concentrations than participants who were classified as having an average campesterol-to-lathosterol ratio upon consumption of the lutein-enriched egg yolk drink (P < 0.05). Moreover, the change in serum HDL cholesterol upon consumption was significantly different between these 3 groups (P < 0.05). We suggest that cholesterol absorbers particularly might benefit from the lutein-enriched buttermilk drink. This study was registered at clinicaltrials.gov as NCT00902408.

Increases in plasma lutein through supplementation are correlated with increases in physical activity and reductions in sedentary time in older adults

Cross-sectional studies have reported positive relationships between serum lutein concentrations and higher physical activity levels. The purpose of the study was to determine whether increasing plasma lutein levels increases physical activity. Forty-four older adults (BMI, 25.3 ± 2.6 kg/m²; age, 68.8 ± 6.4 year) not meeting Australian physical activity guidelines (150 min/week of moderate to vigorous activity) were randomized to consume capsules containing 21 mg of lutein or placebo with 250 mL of full-cream milk per day for 4 weeks and encouraged to increase physical activity. Physical activity was assessed by self-report, pedometry and accelerometry (daily activity counts and sedentary time). Exercise self-efficacy was assessed by questionnaire. Thirty-nine participants competed the study (Lutein = 19, Placebo = 20). Lutein increased plasma lutein concentrations compared with placebo (p < 0.001). Absolute and percentage changes in plasma lutein were inversely associated with absolute (r = −0.36, p = 0.03) and percentage changes (r = −0.39, p = 0.02) in sedentary time. Percentage change in plasma lutein was positively associated with the percentage change in average daily activity counts (r = 0.36, p = 0.03). Exercise self-efficacy did not change (p = 0.16). Lutein increased plasma lutein, which was associated with increased physical activity and reduced sedentary time in older adults. Larger trials should evaluate whether Lutein can provide health benefits over the longer term.

Effects of lutein and lycopene on carotid intima-media thickness in Chinese subjects with subclinical atherosclerosis: a randomised, double-blind, placebo-controlled trial

The aim of the present study was to evaluate the effects of lutein and lycopene supplementation on carotid artery intima-media thickness (CAIMT) in subjects with subclinical atherosclerosis. A total of 144 subjects aged 45-68 years were recruited from local communities. All the subjects were randomly assigned to receive 20 mg lutein/d (n 48), 20 mg lutein/d+20 mg lycopene/d (n 48) or placebo (n 48) for 12 months. CAIMT was measured using Doppler ultrasonography at baseline and after 12 months, and serum lutein and lycopene concentrations were determined using HPLC. Serum lutein concentrations increased significantly from 0·34 to 1·96 μmol/l in the lutein group (P< 0·001) and from 0·35 to 1·66 μmol/l in the combination group (P< 0·001). Similarly, serum lycopene concentrations increased significantly from 0·18 to 0·71 μmol/l in the combination group at month 12 (P< 0·001), whereas no significant change was observed in the placebo group. The mean values of CAIMT decreased significantly by 0·035 mm (P= 0·042) and 0·073 mm (P< 0·001) in the lutein and combination groups at month 12, respectively. The change in CAIMT was inversely associated with the increase in serum lutein concentrations (P< 0·05) in both the active treatment groups and with that in serum lycopene concentrations (β = - 0·342, P= 0·031) in the combination group. Lutein and lycopene supplementation significantly increased the serum concentrations of lutein and lycopene with a decrease in CAIMT being associated with both concentrations. In addition, the combination of lutein and lycopene supplementation was more effective than lutein alone for protection against the development of CAIMT in Chinese subjects with subclinical atherosclerosis, and further studies are needed to confirm whether synergistic effects of lutein and lycopene exist.

Can carotenoids attenuate vascular aging?

One of the main manifestations of vascular aging is the development of atherosclerotic lesions. These lesions become unstable and prone to rupture due to the formation of reactive oxygen species (ROS) that are produced by the inflammatory milieu in the atherosclerotic plaque. The carotenoids are a group of red, orange, or yellow pigmented polyisoprenoid hydrocarbons synthesized by prokaryotes and higher plants. Lycopene, lutein, and other carotenoids have anti-oxidant activity that attenuates the inflammatory atherosclerotic process and delays vascular aging. This ability improves endothelial function due to the increase in bioavailability of NO. Carotenoid consumption also improves the metabolic profile, decreasing the incidence of diabetes, lowering LDL levels, and improving blood pressure control. The beneficial metabolic effect is translated to improvement in atherosclerosis, which is characterized by a decrease in carotid intima-media thickness. The favorable anti-atherosclerotic effect of carotenoids was also demonstrated in cross-sectional population studies showing a positive correlation between low carotenoid levels and adverse cardiovascular outcome. However, carotenoid utilization failed to decrease major cardiovascular and cerebrovascular events in randomized control double blind trials. The main still unanswered question is: What is the therapeutic role of carotenoids in atherosclerotic disease? Is their anti-atherosclerotic effect restricted to primary prevention or can it alter the prognosis of existing cardiovascular and cerebrovascular diseases?

Serum carotenoids reduce progression of early atherosclerosis in the carotid artery wall among Eastern Finnish men

BACKGROUND

Several previous epidemiologic studies have shown that high blood levels of carotenoids may be protective against early atherosclerosis, but results have been inconsistent. We assessed the association between atherosclerotic progression, measured by intima-media thickness of the common carotid artery wall, and serum levels of carotenoids.

METHODS

We studied the effect of carotenoids on progression of early atherosclerosis in a population-based study. The association between concentrations of serum carotenoids, and intima-media thickness of the common carotid artery wall was explored in 840 middle-aged men (aged 46-65 years) from Eastern Finland. Ultrasonography of the common carotid arteries were performed at baseline and 7-year follow-up. Serum levels of carotenoids were analyzed at baseline. Changes in mean and maximum intima media thickness of carotid artery wall were related to baseline serum carotenoid levels in covariance analyses adjusted for covariates.

RESULTS

In a covariance analysis with adjustment for age, ultrasound sonographer, maximum intima media thickness, examination year, body mass index, systolic blood pressure, smoking, physical activity, serum LDL cholesterol, family history of coronary heart disease, antihypertensive medication and serum high sensitivity C-reactive protein, 7-year change in maximum intima media thickness was inversely associated with lycopene (p = 0.005), α-carotene (p = 0.002) and β-carotene (p = 0.019), respectively.

CONCLUSIONS

The present study shows that high serum concentrations of carotenoids may be protective against early atherosclerosis.

Effects of lutein supplement on serum inflammatory cytokines, ApoE and lipid profiles in early atherosclerosis population

AIM

The purpose of this study was to determine the effects of lutein supplement on serum cytokines, apoE and lipoprotein profiles in early atherosclerosis population.

METHODS

Early atherosclerosis patients (n= 65) were randomized to receive placebo (A+P, n= 31) or 20 mg/d lutein (A+L, n= 34) for 3 months.

RESULTS

Serum lutein increased significantly compared to baseline after lutein supplements in A+L group (p<0.001). Lutein supplements resulted in a significant decrease in serum interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) at 3 month in A+L group (p<0.05). Intragroup comparison revealed a significant difference in the changes of serum MCP-1 between A+L and A+P groups (p= 0.021). The serum low-density lipoprotein (LDL) and triglyceride (TG) significantly decreased in A+L group (p<0.05). The changes in serum lutein were negatively associated with those in serum LDL in A+L group (r=-0.384, p=0.043), while no such relationship was observed in A+P group (r= 0.087, p= 0.685).

CONCLUSION

An increase in serum lutein after supplementation can reduce inflammatory cytokines and regulate serum lipids, which may pay important roles in early atherosclerosis.

Serum carotenoids in relation to risk factors for development of atherosclerosis

OBJECTIVE

To explore associations between serum carotenoids and risk factors for development of atherosclerosis.

DESIGN AND METHODS

We studied 40 early atherosclerosis patients without clinical cardiovascular events and comparable healthy controls aged 45-68 years. Intima-media thickness (IMT) and arterial stiffness were simultaneously measured by carotid ultrasonography, and serum carotenoids and cytokines were determined by high-pressure liquid chromatograph (HPLC) and ELISA kits respectively. We evaluated the associations between serum carotenoids, early atherosclerosis and serum cytokines.

RESULTS

Serum concentrations of lutein and zeaxanthin in early atherosclerosis patients were significantly lower than those of control subjects. PCA logistic analysis found that serum carotenoids were associated with decreased risk of atherosclerosis. In contrast, blood pressure, body mass index and serum triglyceride were positively related to the risk of atherosclerosis. Ridge regression analysis revealed that serum carotenoids were associated with inflammatory cytokines and apoE. More specifically, serum lutein was inversely associated with IL-6 (P<0.001) and positively associated IFN-γ (P=0.002). In contrast, zeaxanthin had a significant negative association with VCAM-1 (P=0.001) and apoE (P=0.022) .Lycopene was inversely associated with VCAM-1(P=0.011) and LDL (P=0.046).

CONCLUSIONS

The results suggested that early atherosclerosis patients had lower serum concentrations of lutein and zeaxanthin than healthy subjects. Serum carotenoids were associated with reduced risk of atherosclerosis. The associations between serum carotenoids and inflammatory cytokines may help to explain the possible protective effects of carotenoids on atherosclerosis.