A lutein-enriched diet prevents cholesterol accumulation and decreases oxidized LDL and inflammatory cytokines in the aorta of guinea pigs

Lutein, zeaxanthin, and meso-zeaxanthin supplementation attenuates inflammatory cytokines and markers of oxidative cardiovascular processes in humans

BACKGROUND AND AIMS

Systemic inflammation and oxidation are primary contributors to the development of atherosclerosis. Oxidation of low-density lipoprotein (LDL) particles within the vascular endothelium has been hypothesized to be an initial step in the formation of atherosclerotic plaques, with inflammatory cytokines serving as the signaling mechanism for concomitant macrophage activation. Supplementation with the antioxidative macular xanthophylls (lutein [L], zeaxanthin [Z], and meso-zeaxanthin [MZ]) has been shown to aid in the reduction of inflammatory physiologic responses; therefore, we hypothesized that in our study population, supplementation with these xanthophylls would facilitate a systemic reduction in markers of inflammation and cardiovascular lipid oxidation.

METHODS AND RESULTS

In this double-blind placebo-controlled supplementation study, participants were randomly allocated to receive the active intervention containing L (10 mg) + MZ (10 mg) + Z (2 mg) or placebo (containing sunflower oil). Serum concentrations of carotenoids (assessed by HPLC), inflammatory cytokines (IL-6, IL-1β, TNF-α) and oxidized LDL (OxLDL; by solid-phase sandwich ELISA) were measured at baseline and at 6-months. Results showed that over the supplementation period, compared to placebo, the active group demonstrated statistically significant increases in serum concentrations of L, Z, & MZ (p < 0.05), reductions in inflammatory cytokines IL-1β (p < 0.001) and TNF-α (p = 0.003), as well as a corresponding reduction in serum OxLDL (p = 0.009).

CONCLUSIONS

Our data show that L, Z, & MZ supplementation results in decreased serum IL-1β, TNF-α, and OxLDL. This suggests that these carotenoids are acting systemically to attenuate oxidative lipid products and inflammation, thus reducing their contribution to atherosclerotic plaque formation.

Innovative Bioactive Products with Medicinal Value from Microalgae and Their Overall Process Optimization through the Implementation of Life Cycle Analysis-An Overview

Microalgae are being recognized as valuable sources of bioactive chemicals with important medical properties, attracting interest from multiple industries, such as food, feed, cosmetics, and medicines. This review study explores the extensive research on identifying important bioactive chemicals from microalgae, and choosing the best strains for nutraceutical manufacturing. It explores the most recent developments in recovery and formulation strategies for creating stable, high-purity, and quality end products for various industrial uses. This paper stresses the significance of using Life Cycle Analysis (LCA) as a strategic tool with which to improve the entire process. By incorporating LCA into decision-making processes, researchers and industry stakeholders can assess the environmental impact, cost-effectiveness, and sustainability of raw materials of several approaches. This comprehensive strategy will allow for the choosing of the most effective techniques, which in turn will promote sustainable practices for developing microalgae-based products. This review offers a detailed analysis of the bioactive compounds, strain selection methods, advanced processing techniques, and the incorporation of LCA. It will serve as a valuable resource for researchers and industry experts interested in utilizing microalgae for producing bioactive products with medicinal properties.

Eggs and a Fiber-Rich Diet Are Beneficially Associated with Lipid Levels in Framingham Offspring Study Adults

Background

For many years, United States' dietary policy recommended limiting egg intake to no more than 3/wk in the belief that restricting dietary cholesterol would lower plasma cholesterol levels and thereby reduce the risk of cardiovascular disease. The evidence supporting these recommendations is controversial.

Objectives

To examine the impact of eggs, a major contributor to dietary cholesterol intake, on lipid levels and to determine whether these egg effects are modified by other healthy dietary factors in adults.

Methods

Males and females aged 30-64 y with available 3-d diet record data, without cardiovascular disease and not taking lipid- or glucose-lowering medications in the prospective Framingham Offspring cohort were included (n = 1852). Analysis of covariance models were used to compare mean follow-up lipid levels adjusting for age, sex, BMI, and dietary factors. Cox proportional hazard's models were used to estimate risk for elevated lipid levels.

Results

Consuming ≥5 eggs/wk was not adversely associated with lipid outcomes. Among men, consuming ≥5 (compared with <0.5) eggs/wk was associated with an 8.6 mg/dL lower total cholesterol level and a 5.9 mg/dL lower LDL cholesterol level, as well as lower triglycerides. Overall, higher egg intake combined with higher dietary fiber (compared with lower intakes of both) was associated with the lowest total cholesterol, LDL cholesterol, and LDL cholesterol-to-HDL cholesterol ratio. Finally, diets with higher (compared with lower) egg intakes in combination with higher total fish or fiber intakes, respectively, were associated with lower risks of developing elevated (>160 mg/dL) LDL cholesterol levels (hazard ratio: 0.61; 95% confidence interval: 0.44, 0.84; and HR: 0.70; 95% confidence interval: 0.49, 0.98, respectively).

Conclusions

Higher egg intakes were beneficially associated with serum lipids among healthy adults, particularly those who consumed more fish and dietary fiber.

Microalgal lutein: Advancements in production, extraction, market potential, and applications

Lutein, a bioactive xanthophyll, has recently attracted significant attention for numerous health benefits, e.g., protection of eye health, macular degeneration, and acute and chronic syndromes etc. Microalgae have emerged as the best platform for high-value lutein production with high productivity, lutein content, and scale-up potential. Algal lutein possesses numerous bioactivities, hence widely used in pharmaceuticals, nutraceuticals, aquaculture, cosmetics, etc. This review highlights advances in upstream lutein production enhancement and feasible downstream extraction and cell disruption techniques for a large-scale lutein biorefinery. Besides bioprocess-related advances, possible solutions for existing production challenges in microalgae-based lutein biorefinery, market potential, and emerging commercial scopes of lutein and its potential health applications are also discussed. The key enzymes involved in the lutein biosynthesizing Methyl-Erythritol-phosphate (MEP) pathway have been briefly described. This review provides a comprehensive updates on lutein research advancements covering scalable upstream and downstream production strategies and potential applications for researchers and industrialists.

A Narrative Review: The Effect and Importance of Carotenoids on Aging and Aging-Related Diseases

Aging is generally defined as a time-dependent functional decline that affects most living organisms. The positive increase in life expectancy has brought along aging-related diseases. Oxidative stress caused by the imbalance between pro-oxidants and antioxidants can be given as one of the causes of aging. At the same time, the increase in oxidative stress and reactive oxygen species (ROS) is main reason for the increase in aging-related diseases such as cardiovascular, neurodegenerative, liver, skin, and eye diseases and diabetes. Carotenoids, a natural compound, can be used to change the course of aging and aging-related diseases, thanks to their highly effective oxygen-quenching and ROS-scavenging properties. Therefore, in this narrative review, conducted using the PubMed, ScienceDirect, and Google Scholar databases and complying with the Scale for the Assessment of Narrative Review Articles (SANRA) guidelines, the effects of carotenoids on aging and aging-related diseases were analyzed. Carotenoids are fat-soluble, highly unsaturated pigments that occur naturally in plants, fungi, algae, and photosynthetic bacteria. A large number of works have been conducted on carotenoids in relation to aging and aging-related diseases. Animal and human studies have found that carotenoids can significantly reduce obesity and fatty liver, lower blood sugar, and improve liver fibrosis in cirrhosis, as well as reduce the risk of cardiovascular disease and erythema formation, while also lowering glycated hemoglobin and fasting plasma glucose levels. Carotenoid supplementation may be effective in preventing and delaying aging and aging-related diseases, preventing and treating eye fatigue and dry eye disease, and improving macular function. These pigments can be used to stop, delay, or treat aging-related diseases due to their powerful antioxidant, restorative, anti-proliferative, anti-inflammatory, and anti-aging properties. As an increasingly aging population emerges globally, this review could provide an important prospective contribution to public health.

Eggs Improve Plasma Biomarkers in Patients with Metabolic Syndrome Following a Plant-Based Diet-A Randomized Crossover Study

Plant-based (PB) diets are considered a healthy dietary pattern; however, eggs are not always included in this dietary regime. We hypothesized that the addition of two eggs per day would increase HDL cholesterol as well as plasma lutein, zeaxanthin and choline in individuals with metabolic syndrome (MetS). In this randomized controlled crossover intervention, we recruited 30 participants (49.3 ± 8 y) with MetS who followed a PB diet for 13 weeks. A registered dietitian advised all subjects on food selection and followed them through the intervention to ensure compliance. Participants underwent a 2-week washout with no eggs or spinach (a source of dietary lutein and zeaxanthin) and were randomly allocated to consume spinach (70 g) with either two eggs (EGG) or the equivalent amount of egg substitute (SUB) for breakfast for 4 weeks. After a 3-week washout, they were allocated the alternate breakfast. A total of 24 participants (13 women/11 men) finished the intervention. Plasma lipids, glucose, insulin, anthropometrics, plasma lutein, zeaxanthin, choline and trimethylamine oxide (TMAO) were assessed at baseline and the end of each intervention. When we compared individuals consuming the EGG versus the SUB breakfast, we observed a lower body weight (p < 0.02) and a higher HDL cholesterol (p < 0.025) after the EGG diet. There were no differences in plasma LDL cholesterol, triglycerides, glucose, insulin, or blood pressure. The number of large HDL particles measured by NMR was higher after EGG (p < 0.01) as compared to SUB. Plasma choline was higher in both treatments (p < 0.01) compared to baseline (8.3 ± 2.1 μmol/L). However, plasma choline values were higher in EGG (10.54 ± 2.8 μmol/L) compared to SUB (9.47 ± 2.7 μmol/L) p < 0.025. Both breakfasts increased plasma lutein compared to baseline (p < 0.01), while plasma zeaxanthin was only increased in the egg intervention (p < 0.01). These results indicate that consuming a plant-based diet in combination with whole eggs increases plasma HDL cholesterol, choline and zeaxanthin, important biomarkers in subjects with MetS.

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.

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

Acute inflammation is a key component of the immune system’s response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as α- and β-carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, α- and β-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.

Administration of hydro-alcoholic extract of spinach improves oxidative stress and inflammation in high-fat diet-induced NAFLD rats

Background

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. The aim of this study was to evaluate the effects of hydro-alcoholic extract of spinach (HES) on hepatic and serum measurements of NAFLD in a rat model.

Methods

In the prevention phase, 18 Sprague–Dawley rats were fed a high-fat diet, a high-fat diet plus 400 mg/kg HES, or a chow diet for seven weeks. For the treatment phase, after the induction of NAFLD, they were fed a high-fat diet, a high-fat diet plus 400 mg/kg HES, a chow diet, or a chow diet plus 400 mg/kg HES for four weeks (n = 6).

Results

Administration of HES combined with high-fat diet in rats was associated with decreased food intake (P < 0.01), weight loss (P = 0.01), and increased superoxide dismutase (SOD) (P = 0.02) enzyme activity in the liver, at the end of the prevention phase. hs-CRP (P < 0.05), PTX-3 (P < 0.05), and TNF-α (P < 0.05) gene expression in the liver were decreased and PPAR-γ (P < 0.05) gene expression in the liver was increased by spinach intake, both in the prevention and treatment phases. Furthermore, administration of spinach in the treatment phase increased serum TAC (P = 0.03) and hepatic GPX (P = 0.01) enzyme activity.

Conclusion

Taking into account the potential beneficial effects of HES on prevention and treatment of NAFLD in the present study, to confirm these findings, we propose that further clinical trials be conducted on human subjects with NAFLD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03396-x.

Lutein exerts its cardioprotective effect against the experimental model of isoprenaline-induced myocardial infarction via MIAT/miR-200a/Nrf2/TXINP pathway

Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. Lutein (LU) possesses numerous pharmacological activities, including anti-inflammatory, antioxidant, and antiapoptotic effects. This study aimed to investigate the cardioprotective potential of LU in isoprenaline (ISO)-induced MI and to explore its molecular mechanisms of action. AMI was induced by two consecutive subcutaneous doses of ISO (65 mg/kg; s.c.). The LU group was pretreated with LU (20 mg/kg; p.o.) for 30 days followed by ISO injections on Days 29 and 30. ISO group showed elevated serum creatine kinas-MB (CK-MB) and considerable electrocardiographic changes along with reduced ejection fraction compared to the normal group. LU pretreatment could decrease serum CK-MB activity, normalize QRS and QTc intervals and restore ejection fraction compared to the untreated group. The ISO group demonstrated infarcted-like lesions, which were ameliorated in the LU-pretreated group. Immunohistochemical investigation revealed upregulated cardiac troponin T (cTn T) and desmin expressions in the LU-pretreated group. LU pretreatment also enhanced cardiac thioredoxin (Trx) and glutathione (GSH) contents as well as reduced lipid peroxidation, compared to the untreated group. Importantly, LU pretreatment could downregulate long noncoding MI associated transcript (lncRNA MIAT) and thioredoxin-interacting protein (TXNIP) and augment micro RNA (miR)-200a and nuclear factor erythroid 2-related factor 2 (Nrf2) expressions compared to the ISO group. Moreover, a significant inverse correlation between MIAT and miR-200a was observed. In conclusion, this study revealed that LU could ameliorate ISO-induced MI in rats by modulating MIAT/miR-200a/Nrf2 pathway.

Association between egg consumption and arterial stiffness: a longitudinal study

BACKGROUND

Inconsistent associations between egg consumption and cardiovascular disease (CVD) risk have been observed in previous studies. This study aims to longitudinally investigate the association between egg consumption and altered risk of arterial stiffness, a major pre-clinical pathogenic change of CVD, which was assessed by brachial-ankle pulse wave velocity (baPWV).

METHODS

A total of 7315 Chinese participants from the Kailuan Study, free of CVD and cancer were included in this study. Egg consumption was assessed by a semi-quantitative validated food frequency questionnaire in 2014. baPWV was repeatedly measured at baseline and during follow-up (mean follow-up: 3.41 years). General linear regression was used to calculate means of baPWV change rate across different egg consumption groups, adjusting for age, sex, baseline baPWV, healthy eating index, total energy, social-economic status, blood pressure, obesity, smoking, lipid profiles, and fasting glucose concentrations.

RESULTS

Compared to the annual baPWV change rate in participants with 0-1.9 eggs/wk. (adjusted mean: 35.9 ± 11.2 cm/s/y), those consuming 3-3.9 eggs/wk. (adjusted mean: 0.2 ± 11.4 cm/s/y) had the lowest increase in baPWV during follow-up (P-difference = 0.002). Individuals with low (0-1.9 eggs/wk) vs. high (5+ eggs /wk) egg intake showed similar changes in baPWV.

CONCLUSIONS

In this large-scale longitudinal analysis, we did not find a significant difference in arterial stiffness, as assessed by baPWV level, between low and high egg consumption groups. However, moderate egg consumption (3-3.9 eggs/wk) appeared to have beneficial effects on arterial stiffness.

Serum and Macular Carotenoids in Relation to Retinal Vessel Caliber Fifteen Years Later, in the Second Carotenoids in Age-Related Eye Disease Study

Purpose

We investigated whether dietary carotenoids lutein and zeaxanthin (L/Z) in the serum and macula were associated with central retinal arteriole and venule calibers in a follow-up ancillary study among older women in the Women's Health Initiative.

Methods

Among 390 women who participated in Carotenoids in Age-Related Eye Disease Study 2 (CAREDS2) (2016–2019), we investigated associations between serum L/Z at Women's Health Initiative baseline (1994–1998), and macular pigment optical density (MPOD) at CAREDS baseline (2001–2004), with central retinal vessel caliber in CAREDS2. MPOD was measured using heterochromatic flicker photometry (0.5° from the foveal center) in CAREDS baseline and CAREDS2. Vessel calibers were measured from fundus photographs (CAREDS2). We also explored associations in women with stable MPOD (±0.10 optical density units) over 15 years (n = 106), given the long-term increases in MPOD related to diet patterns and supplement use. Associations were investigated using linear modeling.

Results

In the full sample (n = 390), higher serum L/Z (tertile 3 vs. 1) was positively associated with arteriole caliber (mean ± SE, 145.0 ± 1.4 µm vs. 140.8 ± 1.4 µm; P = 0.05) and venule caliber (214.6 ± 2.2 µm vs. 207.5 ± 2.2 µm; P = 0.03). MPOD was also associated with wider vessel calibers (tertile 3 vs. 1), but the trend was only statistically significant for venules (144.4 ± 1.4 µm vs. 141.1 ± 1.4 µm [P = 0.12] and 213.3 ± 2.1 µm vs. 206.0 ± 2.1 µm [P = 0.02], respectively.) Most associations were strengthened in women with stable MPOD over 15 years, including between MPOD and arteriole caliber (149.8 ± 2.6 µm vs.135.8 ± 3.0 µm; P = 0.001).

Conclusions

Higher L/Z status in serum and retina was associated with larger central retinal vessel calibers. Prospective studies and clinical trials are needed to elucidate whether L/Z supplementation prevents vision loss through increasing blood flow.

Xanthophylls from the Sea: Algae as Source of Bioactive Carotenoids

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

Lutein supplementation combined with a low-calorie diet in middle-aged obese individuals: effects on anthropometric indices, body composition and metabolic parameters

Lutein is considered as a major biologically active carotenoid, with potential benefits for obesity and cardiometabolic health. This double-blind, randomised controlled trial aimed to assess whether the consumption of lutein along with a low-calorie diet (LCD) can influence anthropometric indices, body composition and metabolic parameters in obese middle-aged individuals. After a 2-week run-in period with an LCD, forty-eight participants aged 45–65 years were randomly assigned to consume 20 mg/d lutein or placebo along with the LCD for 10 weeks. Dietary intake, anthropometric indices, body composition, lipid profile, glucose homoeostasis parameters, NEFA and appetite sensations were assessed at the beginning and end of the study. After 10 weeks, body weight and waist circumference significantly decreased in both groups, although between-group differences were not significant. There was more of a decrease in the percentage of body fat in the lutein group v. the placebo group. Moreover, the placebo group experienced a significant reduction in fat-free mass (FFM), whereas the lutein group preserved FFM during calorie restriction, although the between-group difference did not reach statistical significance. Visceral fat and serum levels of total cholesterol (TC) and LDL-cholesterol were significantly decreased only in the lutein group, with a statistically significant difference between the two arms only for TC. No significant changes were observed in the TAG, HDL-cholesterol, glucose homoeostasis parameters, NEFA and appetite sensations. Lutein supplementation in combination with an LCD could improve body composition and lipid profile in obese middle-aged individuals.

Loading of lutein in egg-sphingomyelin vesicles as lipid carriers: Thermotropic phase behaviour, structure of sphingosome membranes and lutein crystals

Lutein is a xanthophyll carotenoid provided exclusively by the diet, that has protective functions and beneficial effects on human health. Supplementation in lutein is necessary to reach the recommended daily dietary intake. However, the introduction of lutein into foods and beverages is a real challenge since this lipophilic nutrient has a poor aqueous solubility and a low bioavailability. In this study, we investigated the capacity of egg-sphingomyelin (ESM) vesicles called sphingosomes to solubilise lutein into the bilayers. The thermal and structural properties of ESM bilayers were examined in presence of various amounts of lutein by differential scanning calorimetry (DSC) and temperature-controlled X-ray diffraction (XRD), the structures of sphingosomes and lutein crystals were observed by microscopic techniques. ESM bilayers were in the fluid L_α phase above the phase transition temperature T_m = 39.6 °C and in the lamellar ripple P_β' phase below T_m where ESM sphingosomes exhibited ondulations and were facetted. Lutein molecules were successfully incorporated into the ESM bilayers where they induced a structural disorganisation. For ESM/lutein 90/10 %mol (91.8/8.2 %wt; 89 mg lutein / g ESM), lutein partitioning occured with the formation of lutein crystals in the aqueous phase together with lutein-loaded ESM vesicles. This study highlighted the capacity of new lipid carriers such as egg-sphingosomes to solubilise lutein and opens perspectives for the formulation of effective lutein-fortified functionnal foods and beverages providing health benefits.

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.

Direct Extraction of Lutein from Wet Macroalgae by Liquefied Dimethyl Ether without Any Pretreatment

Extraction of lutein from raw macroalgae Monostroma nitidum was conducted using a simple method employing dimethyl ether (DME) as a solvent. DME extraction enabled omission of conventional drying and cell wall disruption steps, yielding 0.30 mg/g dry lutein from wet M. nitidum. The yield of extracted lutein was higher than that by chloroform-methanol extraction from freeze-dried and cell-disrupted M. nitidum. DME extraction provides a safe, eco-friendly approach that combines high yields of lutein with unheated drying of wet macroalgae in a single step.

Small rodent models of atherosclerosis

The ease of breeding, low cost of maintenance, and relatively short period for developing atherosclerosis make rodents ideal for atherosclerosis research. However, none of the current models accurately model human lipoprotein profile or atherosclerosis progression since each has its advantages and disadvantages. The advent of transgenic technologies much supports animal models' establishment. Notably, two classic transgenic mouse models, apoE-/- and Ldlr-/-, constitute the primary platforms for studying underlying mechanisms and development of pharmaceutical approaches. However, there exist crucial differences between mice and humans, such as the unhumanized lipoprotein profile, and the different plaque progression and characteristics. Among rodents, hamsters and guinea pigs might be the more realistic models in atherosclerosis research based on the similarities in lipoprotein metabolism to humans. Studies involving rat models, a rodent with natural resistance to atherosclerosis, have revealed evidence of atherosclerotic plaques under dietary induction and genetic manipulation by novel technologies, notably CRISPR-Cas9. Ldlr-/- hamster models were established in recent years with severe hyperlipidemia and atherosclerotic lesion formation, which could offer an alternative to classic transgenic mouse models. In this review, we provide an overview of classic and innovative small rodent models in atherosclerosis researches, including mice, rats, hamsters, and guinea pigs, focusing on their lipoprotein metabolism and histopathological changes.

Niacin, lutein and zeaxanthin and physical activity have an impact on Charlson comorbidity index using zero-inflated negative binomial regression model: National Health and Nutrition Examination Survey 2013-2014

Background

Combined with the increasing life expectancy, chronic medical conditions have gradually become the dominant cause of death and disability, and multimorbidity became an increasingly serious public health challenge. However, most existing studies have focused on the coexistence of specific diseases or relatively few diseases. Given one person may have multiple diseases at the same time, we applied Charlson Comorbidity Index (CCI) to systematically evaluate one’s 10-year mortality. In this study, we explored the effects of nutrients and physical activity on CCI using National Health and Nutrition Examination Survey (NHANES) 2013–2014 data.

Methods

The study sample consists of one continuous cycle (2013–2014) of NHANES, and 4386 subjects were included in the study. Nutrients intake was measured by dietary recall, and physical activity was evaluated by the Global Physical Activity Questionnaire respectively. Besides, CCI was the sum of the scores assigned for each medical condition. We utilized zero-inflated negative binomial (ZINB) model to investigate the effects in nutrients intake and physical activity on CCI by adjusting for seven sociodemographic characteristics, smoking and drinking.

Results

Among the 4386 participants, 2018 (68.7%) are Non-Hispanic White, over half participants (78.6%) drink. In count part (CCI ≥ 0), holding other variables constant, the expected change in CCI for a one-unit increase in niacin is 1.621(RR = 1.621, p = 0.016), in lutein + zeaxanthin is 0.974 (RR = 0.974, p = 0.031), and in sedentary time is 1.035 (RR = 1.035, p = 0.005). Moreover, those who do not have vigorous work activity would be more likely to have higher CCI than those who have (RR = 1.275, P = 0.045). In logit part (CCI = 0), the log odds of having CCI equals zero would increase by 0.541 and 0.708 for every additional vigorous recreational activity (OR = 0.541, p = 0.004) and moderate recreational activity (OR = 0.708, p = 0.017) respectively.

Conclusions

Lutein and zeaxanthin intake, vigorous work activity, vigorous recreational activity and moderate recreational activity may be good for one’s health. Rather, increasing niacin intake and sedentary activity may be likely to raise 10-year mortality. Our findings may be significant for preventing diseases and improving health, furthermore, reducing people’s financial burden on healthcare.

Effect of lutein on methotrexate-induced oxidative lung damage in rats: a biochemical and histopathological assessment

BACKGROUND/AIMS

This study aimed to investigate the effect of lutein on methotrexate (MTX)-induced pulmonary toxicity in rats biochemically and histopathologically.

METHODS

The rats in the MTX + lutein (MTXL, n = 6) group were given 1 mg/kg of lutein orally. A 0.9% NaCl solution was administered orally to the MTX (n = 6) group and the healthy group (HG, n = 6). One hour later, a single 20 mg/kg dose of MTX was injected intraperitoneally in the MTXL and MTX. Lutein or 0.9% NaCl solution was administered once a day for 5 days. At the end of this period, malondialdehyde (MDA), myeloperoxidase (MPO), total glutathione (tGSH), interleukin 1 beta (IL-1β), and tumor necrosis factor alpha (TNF-α) were measured in the lung tissues from the animals euthanized with 50 mg/kg thiopental sodium anesthesia. Subsequently, histopathological examinations were performed.

RESULTS

The levels of MDA, MPO, IL-1β, and TNF-α in the lung tissue of the MTX were significantly higher than those of the MTXL and HG groups (p < 0.0001), and the amount of tGSH was lower. The histopathological findings in the MTX group, in which the oxidants and cytokines were higher, were more severe.

CONCLUSION

Lutein prevented the MTX-induced oxidative lung damage biochemically and histopathologically. This result indicates that lutein may be useful in the treatment of MTX-induced lung damage.

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.

Construction of a pathway to C50-ε-carotene

Substrate tolerance of bacterial cyclases has been demonstrated in various contexts, but little is known about that of plant cyclases. Here, we tested two plant ε-cyclases to convert C₅₀-lycopene, which we previously established by rounds of directed evolution. Unlike bacterial β-cyclases, two-end cyclase from lettuce exhibited complete specificity against this molecule, indicating that this enzyme has some mechanism that exerts size-specificity. Arabidopsis one-end cyclase At-y2 showed detectable activity to C₅₀-lycopene. Interestingly, we found that it functions as a two-end cyclase in a C₅₀ context. Based on this observation, a possible model for substrate discrimination of this enzyme is proposed.

The Effect of Lutein on Eye and Extra-Eye Health

Lutein is a carotenoid with reported anti-inflammatory properties. A large body of evidence shows that lutein has several beneficial effects, especially on eye health. In particular, lutein is known to improve or even prevent age-related macular disease which is the leading cause of blindness and vision impairment. Furthermore, many studies have reported that lutein may also have positive effects in different clinical conditions, thus ameliorating cognitive function, decreasing the risk of cancer, and improving measures of cardiovascular health. At present, the available data have been obtained from both observational studies investigating lutein intake with food, and a few intervention trials assessing the efficacy of lutein supplementation. In general, sustained lutein consumption, either through diet or supplementation, may contribute to reducing the burden of several chronic diseases. However, there are also conflicting data concerning lutein efficacy in inducing favorable effects on human health and there are no univocal data concerning the most appropriate dosage for daily lutein supplementation. Therefore, based on the most recent findings, this review will focus on lutein properties, dietary sources, usual intake, efficacy in human health, and toxicity.

Egg consumption is associated with a lower risk of type 2 diabetes in middle-aged and older men

BACKGROUND/OBJECTIVES

This prospective study examined gender-specific associations between egg intake and the risk of developing type 2 diabetes using data from a large-scale cohort study.

SUBJECTS/METHODS

A total of 7,002 Korean adults (40–69 years) without type 2 diabetes at baseline were analyzed. Dietary intake was evaluated by a food frequency questionnaire administered at baseline (2001–2002) and the second follow-up examination (2005–2006). Type 2 diabetes was diagnosed as a fasting glucose concentration ≥ 126 mg/dL or current use of glucose-lowering medications or insulin injection. Multivariate Cox proportional hazard models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for incident type 2 diabetes according to egg consumption or cholesterol intake.

RESULTS

During a 14-year follow up period, 857 subjects developed type 2 diabetes. In men, frequent egg intake (2- < 4 servings/week) was associated with a 40% lower risk of developing type 2 diabetes than infrequent egg intake (0- < 1 serving/week) (HR = 0.60, 95% CI: 0.37–0.97), whereas no association between egg intake and incidence of type 2 diabetes was observed in women (HR = 0.61, 95% CI: 0.27–1.37). There was no association between cholesterol intake and risk of incident type 2 diabetes in either men or women.

CONCLUSIONS

Egg consumption was inversely related to the risk of incident type 2 diabetes in men, but not in women, suggesting gender differences in the relationship between diet and disease risk.

Lutein prevents osteoarthritis through Nrf2 activation and downregulation of inflammation

INTRODUCTION

Osteoarthritis is an inflammatory disorder associated with oxidative stress and apoptosis leading to cartilage destruction and impairment of cartilage formation. In the present study, we studied the protective effect of lutein against monosodium iodoacetate (MIA)-induced osteoarthritis in primary chondrocyte cells.

MATERIAL AND METHODS

Oxidative stress was determined through testing antioxidant status, reactive oxygen species levels and lipid peroxide content. Also, Nrf2 expression and its downstream target genes HO-1 and NQO-1 were determined. Inflammation was analyzed through NF-κB, COX-2 and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β). In addition, the effects of MIA and lutein on mitochondrial membrane potential and caspase-3 levels were analyzed.

RESULTS

The results showed that lutein treatment significantly increased the cell viability of chondrocytes and offered significant cytoprotection by enhancing the antioxidant defense mechanisms and reducing oxidative stress (reactive oxygen species and lipid peroxidation). Lutein treatment showed anti-inflammatory effects by downregulating inflammatory proteins (NF-κB, COX-2) and pro-inflammatory cytokines (IL-6, TNF-α, IL-1β). Lutein reduced MIA-induced apoptosis through maintaining mitochondrial membrane potential and downregulating caspase-3 activity.

CONCLUSIONS

The present study shows significant cytoprotection offered by lutein against MIA-induced oxidative stress, inflammation and apoptosis by the modulatory effect of NF-κB and Nrf2 activation.

Intake of 3 Eggs per Day When Compared to a Choline Bitartrate Supplement, Downregulates Cholesterol Synthesis without Changing the LDL/HDL Ratio

Cardiovascular disease (CVD) risk is associated with high concentrations of low-density lipoprotein cholesterol (LDL-C). The impact of dietary cholesterol on plasma lipid concentrations still remains a concern. The effects of egg intake in comparison to choline bitartrate supplement was studied in a young, healthy population. Thirty participants were enrolled for a 13-week intervention. After a 2-week run-in period, subjects were randomized to consume either 3 eggs/day or a choline bitartrate supplement (~400 mg choline for both treatments) for 4-weeks each. After a 3-week washout period, they were allocated to the alternate treatment. Dietary records, plasma lipids, apolipoproteins (apo) concentrations, and peripheral blood mononuclear cell expression of regulatory genes for cholesterol homeostasis were assessed at the end of each intervention. Dietary intakes of saturated and monounsaturated fat were higher with the consumption of eggs compared to the choline period. In addition, higher plasma concentrations of total cholesterol (7.5%), high density lipoprotein cholesterol (HDL-C) (5%) and LDL-C (8.1%) were observed with egg consumption (p < 0.01), while no change was seen in LDL-C/HDL-C ratio, a key marker of heart disease risk. Compared to choline supplementation, intake of eggs resulted in higher concentrations of plasma apoA-I (8%) and apoE (17%) with no changes in apoB. Sterol regulatory element-binding protein 2 and 3-hydroxy-3-methylglutaryl-CoA reductase expression were lower with egg consumption by 18% and 31%, respectively (p < 0.05), suggesting a compensation to the increased dietary cholesterol load. Therefore, dietary cholesterol from eggs appears to regulate endogenous synthesis of cholesterol in such a way that the LDL-C/HDL-C ratio is maintained.

Egg consumption may improve factors associated with glycemic control and insulin sensitivity in adults with pre- and type II diabetes

Daily consumption of one large egg for 12 weeks improves fasting blood glucose, ATP-binding cassette protein family A1, and apolipoprotein A1 in overweight or obese individuals with pre- and type II diabetes.

Moringa Leaves Prevent Hepatic Lipid Accumulation and Inflammation in Guinea Pigs by Reducing the Expression of Genes Involved in Lipid Metabolism

To investigate the mechanisms by which Moringa oleifera leaves (ML) modulate hepatic lipids, guinea pigs were allocated to either control (0% ML), 10% Low Moringa (LM) or 15% High Moringa (HM) diets with 0.25% dietary cholesterol to induce hepatic steatosis. After 6 weeks, guinea pigs were sacrificed and liver and plasma were collected to determine plasma lipids, hepatic lipids, cytokines and the expression of genes involved in hepatic cholesterol (CH) and triglyceride (TG) metabolism. There were no differences in plasma lipids among groups. A dose-response effect of ML was observed in hepatic lipids (CH and TG) with the lowest concentrations in the HM group (p < 0.001), consistent with histological evaluation of lipid droplets. Hepatic gene expression of diglyceride acyltransferase-2 and peroxisome proliferator activated receptor-γ, as well as protein concentrations interleukin (IL)-1β and interferon-γ, were lowest in the HM group (p < 0.005). Hepatic gene expression of cluster of differentiation-68 and sterol regulatory element binding protein-1c were 60% lower in both the LM and HM groups compared to controls (p < 0.01). This study demonstrates that ML may prevent hepatic steatosis by affecting gene expression related to hepatic lipids synthesis resulting in lower concentrations of cholesterol and triglycerides and reduced inflammation in the liver.

Carotenoids: biochemistry, pharmacology and treatment

Carotenoids and retinoids have several similar biological activities such as antioxidant properties, the inhibition of malignant tumour growth and the induction of apoptosis. Supplementation with carotenoids can affect cell growth and modulate gene expression and immune responses. Epidemiological studies have shown a correlation between a high carotenoid intake in the diet with a reduced risk of breast, cervical, ovarian, colorectal cancers, and cardiovascular and eye diseases. Cancer chemoprevention by dietary carotenoids involves several mechanisms, including effects on gap junctional intercellular communication, growth factor signalling, cell cycle progression, differentiation-related proteins, retinoid-like receptors, antioxidant response element, nuclear receptors, AP-1 transcriptional complex, the Wnt/β-catenin pathway and inflammatory cytokines. Moreover, carotenoids can stimulate the proliferation of B- and T-lymphocytes, the activity of macrophages and cytotoxic T-cells, effector T-cell function and the production of cytokines. Recently, the beneficial effects of carotenoid-rich vegetables and fruits in health and in decreasing the risk of certain diseases has been attributed to the major carotenoids, β-carotene, lycopene, lutein, zeaxanthin, crocin (/crocetin) and curcumin, due to their antioxidant effects. It is thought that carotenoids act in a time- and dose-dependent manner. In this review, we briefly describe the biological and immunological activities of the main carotenoids used for the treatment of various diseases and their possible mechanisms of action.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

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.

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

Lutein is the predominant carotenoid in the developing primate brain and retina, and may have important functional roles. However, its bioaccumulation pattern during early development is not understood. In this pilot study, we investigated whether carotenoid supplementation of infant formula enhanced lutein tissue deposition in infant rhesus macaques. Monkeys were initially breastfed; from 1 to 3 months of age they were fed either a formula supplemented with lutein, zeaxanthin, β-carotene and lycopene, or a control formula with low levels of these carotenoids, for 4 months (n = 2/group). All samples were analyzed by high pressure liquid chromatography (HPLC). Final serum lutein in the supplemented group was 5 times higher than in the unsupplemented group. All brain regions examined showed a selective increase in lutein deposition in the supplemented infants. Lutein differentially accumulated across brain regions, with highest amounts in occipital cortex in both groups. β-carotene accumulated, but zeaxanthin and lycopene were undetectable in any brain region. Supplemented infants had higher lutein concentrations in peripheral retina but not in macular retina. Among adipose sites, abdominal subcutaneous adipose tissue exhibited the highest lutein level and was 3-fold higher in the supplemented infants. The supplemented formula enhanced carotenoid deposition in several other tissues. In rhesus infants, increased intake of carotenoids from formula enhanced their deposition in serum and numerous tissues and selectively increased lutein in multiple brain regions.

Anti-obesity effects of zeaxanthin on 3T3-L1 preadipocyte and high fat induced obese mice

Zeaxanthin inhibited lipogenesis in adipocytes and attenuated progression of obesity in mice by inducing AMPK activation and suppressing adipocyte-specific factors.

Egg consumption and heart health: A review

Cardiovascular disease is the leading cause of death in the United States. Until recently, reducing dietary cholesterol has been a part of the American Heart Association (AHA) and American College of Cardiology (ACC) guidelines on lifestyle management, despite inconclusive evidence to support the recommendation. Considering eggs are a rich source of dietary cholesterol (typically containing 141-234 mg per egg), individuals with increased risk for CVD are advised not to consume eggs. Furthermore, based on the 2012 AHA/ACC guidelines, individuals with lower risk for CVD have previously been advised to avoid consuming eggs due to the high content of dietary cholesterol. Rather than strictly limiting cholesterol intake, the AHA and ACC guidelines now recommend dietary patterns that emphasize fruits, vegetables, whole grains, low-fat dairy products, poultry, fish, and nuts as an approach to favorably alter blood lipid levels. Of note, the 2015-2020 Dietary Guidelines for Americans have removed the recommendation of limiting cholesterol intake to no more than 300 mg per day; however, the guidelines advise that individuals should eat as little dietary cholesterol as possible while consuming a healthy eating pattern. The purpose of this review is to summarize the documented health risks of egg consumption in individuals with low and high risk for CVD and determine whether current recommendations are warranted based on the available literature. We also aim to provide guidance for future studies that will help further elucidate the health modulating effect of eggs.

The Multiple Facets of Lutein: A Call for Further Investigation in the Perinatal Period

Lutein may have important antioxidant actions in free-radical-mediated diseases, in addition to its well-known antioxidant and cytoprotective effects on macula and photoreceptors. The peculiar perinatal susceptibility to oxidative stress indicates that prophylactic use of antioxidants as lutein could help to prevent or at least to reduce oxidative stress related diseases in newborns. Since lutein is not synthesized by humans, the intake primarily depends on diet or supplementation. Newborns receive lutein exclusively from breast milk. Lutein supplementation in term newborns has been reported to reduce oxidative stress and increase antioxidant capacities in the first days of life. Innovative frontiers concerning lutein supplementation are orientated toward cardiometabolic health improvement and cognitive benefits. The safety of lutein as an antioxidant agent has been confirmed in experimental and clinical studies, but its routine use is not recommended in perinatal period. This review summarizes what is known about the role of lutein as an antioxidant and anti-inflammatory agent in animal model and humans.

Anti-inflammatory and immunomodulatory properties of Carica papaya

Chronic inflammation is linked with the generation and progression of various diseases such as cancer, diabetes and atherosclerosis, and anti-inflammatory drugs therefore have the potential to assist in the treatment of these conditions. Carica papaya is a tropical plant that is traditionally used in the treatment of various ailments including inflammatory conditions. A literature search was conducted by using the keywords "papaya", "anti-inflammatory and inflammation" and "immunomodulation and immune" along with cross-referencing. Both in vitro and in vivo investigation studies were included. This is a review of all studies published since 2000 on the anti-inflammatory activity of papaya extracts and their effects on various immune-inflammatory mediators. Studies on the anti-inflammatory activities of recognized phytochemicals present in papaya are also included. Although in vitro and in vivo studies have shown that papaya extracts and papaya-associated phytochemicals possess anti-inflammatory and immunomodulatory properties, clinical studies are lacking.

Lutein protects against ischemia/reperfusion injury in rat skeletal muscle by modulating oxidative stress and inflammation

BACKGROUND

Lutein is an antioxidant compound with potential biological effects. The present study investigated the protective role of Lutein against I/R injury in skeletal muscle.

METHODS

Animals were divided into three groups. Group I - sham operated; Group II- IR injury- Hind limb ischemia was induced by clamping the common femoral artery and vein. After 4 h of ischemia, the clamp was removed and the animals underwent 2 h of reperfusion. Group III-Lutein + IR injury- Rats with Lutein treatment received intraperitoneal injection 1 h before reperfusion. The skeletal tissues were analyzed for oxidative stress parameters (reactive oxygen species, protein carbonylation and sulfhydryls, lipid peroxidation). Antioxidant status was determined by evaluating Nrf-2 levels and antioxidant enzyme activities. The inflammatory mechanism was determined through NF-κB and COX-2 expressions. Pro-inflammatory cytokines were determined by ELISA.

RESULTS

The results showed that Lutein treatment significantly decreased the oxidative stress by reducing reactive oxygen species, protein carbonylation and sulphydryls, lipid peroxidation. Further, the levels of Nrf-2 and antioxidant status was significantly declined during IR injury compared to sham operated rats. Lutein treatment reduced the oxidative stress by enhancing Nrf-2 levels and antioxidant status. Skeletal IR injury enhanced the inflammatory signaling by up regulating NF-κB, COX-2 and various pro-inflammatory cytokines. NF-κB, COX-2 expressions were down regulated by Lutein treatment.

CONCLUSION

The study shows that Lutein protects against skeletal IR injury by down regulating oxidative stress and inflammatory mechanisms.

Lutein derived fragments exhibit higher antioxidant and anti-inflammatory properties than lutein in lipopolysaccharide induced inflammation in rats

In the present study, we appraise the anti-inflammatory efficacy of lutein oxidative degradation derivatives mediated through UV-irradiation over lutein in counteracting the inflammation induced by lipopolysaccharide (LPS) in rats (n = 5 per group). UV-irradiated lutein fragments were identified as anhydrolutein (B, C40H54O), 2,6,6-trimethylcyclohexa-1,4-dienylium (M1, C9H13), (2E,4E,6E,8E)-9-(4-hydroxy-2,6,6-trimethylcyclohex-1-1en-1-yl)-3,7-dimethylnona-2,4,6,8-tetraen-1-ylium (M2, C20H29O), 4-[(1E,3E,5E,7E)-3,7,-dimethyldeca-1,3,5,7-tetraen-1-yl]-3,5,5-methylcyclohex-3-en-1-ol (M3, C21H30O) and zeaxanthin (M4, C40H56O) and its isomers as 13'-Z zeaxanthin, 13'-Z lutein, all-trans zeaxanthin, and 9-Z lutein. Induction of inflammation by LPS significantly increased the production of nitrites (3.3 fold in the serum and 2.6 fold in the liver), prostaglandin E2 (26 fold in the serum), and pro-inflammatory cytokines like tumor necrosis factor-α (6.6 fold in the serum), and interleukin-6 (4.8 fold in the serum). Oxidative derivatives of lutein, especially M1, M2 and M3, ameliorated acute inflammation in rats by inhibiting the production of nitrites, malondialdehyde (MDA), PGE2, TNF-α, and IL-6 cytokines more efficiently than lutein in rats. The anti-inflammatory mechanism of derivatives might be related to the decrease of inflammatory cytokines and the increase of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione S transferase, glutathione reductase), which would result in the reduction of iNOS, COX-2 and MDA and subsequently inflammatory responses.

Associations of egg and cholesterol intakes with carotid intima-media thickness and risk of incident coronary artery disease according to apolipoprotein E phenotype in men: the Kuopio Ischaemic Heart Disease Risk Factor Study

BACKGROUND

In general populations, the effects of dietary cholesterol on blood cholesterol concentrations are modest. However, the relation is stronger in those with an ɛ4 allele in the apolipoprotein E gene (APOE). There is little information on the association between cholesterol intake and the risk of coronary artery disease (CAD) among those with the ApoE4 phenotype.

OBJECTIVE

We investigated the associations of intakes of cholesterol and eggs, a major source of dietary cholesterol, with carotid intima-media thickness and the risk of incident CAD in middle-aged and older men from eastern Finland.

DESIGN

The study included 1032 men aged 42-60 y in 1984-1989 at the baseline examinations of the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study. Data on common carotid artery intima-media thickness (CCA-IMT) were available for 846 men. Dietary intakes were assessed with 4-d food records. Associations with incident CAD and baseline CCA-IMT were analyzed by using Cox regression and ANCOVA, respectively.

RESULTS

The ApoE4 phenotype was found in 32.5% of the men. During the average follow-up of 20.8 y, 230 CAD events occurred. Egg or cholesterol intakes were not associated with the risk of CAD. Each 1 additional egg (55 g)/d was associated with a multivariable-adjusted HR of 1.17 (95% CI: 0.85, 1.61) in the ApoE4 noncarriers and an HR of 0.93 (95% CI: 0.50, 1.72) in the ApoE4 carriers (P-interaction = 0.34). Each 100-mg/d higher cholesterol intake was associated with an HR of 1.04 (95% CI: 0.89, 1.22) in the ApoE4 noncarriers and an HR of 0.95 (95% CI: 0.73, 1.25) in the ApoE4 carriers (P-interaction = 0.81). Egg or cholesterol intakes were also not associated with increased CCA-IMT.

CONCLUSION

Egg or cholesterol intakes were not associated with increased CAD risk, even in ApoE4 carriers (i.e., in highly susceptible individuals).

Hen Egg as an Antioxidant Food Commodity: A Review

Intake of antioxidants through diet is known to be important in reducing oxidative damage in cells and improving human health. Although eggs are known for their exceptional, nutritional quality, they are not generally considered as antioxidant foods. This review aims to establish the importance of eggs as an antioxidant food by summarizing the current knowledge on egg-derived antioxidants. Eggs have various natural occurring compounds including the proteins ovalbumin, ovotransferrin and lysozyme in egg white, as well as phosvitin, carotenoids and free aromatic amino acids in egg yolk. Some lipophilic antioxidants such as vitamin E, carotenoids, selenium, iodine and others can be transferred from feed into egg yolk to produce antioxidant-enriched eggs. The bioactivity of egg antioxidants can be affected by food processing, storage and gastrointestinal digestion. Generally thermal processing methods can promote loss of antioxidant properties in eggs due to oxidation and degradation, whereas gastrointestinal digestion enhances the antioxidant properties, due to the formation of new antioxidants (free amino acids and peptides). In summary, in addition to its well-known nutritional contribution to our diet, this review emphasizes the role of eggs as an important antioxidant food.

Bioactive Egg Components and Inflammation

Inflammation is a normal acute response of the immune system to pathogens and tissue injury. However, chronic inflammation is known to play a significant role in the pathophysiology of numerous chronic diseases, such as cardiovascular disease, type 2 diabetes mellitus, and cancer. Thus, the impact of dietary factors on inflammation may provide key insight into mitigating chronic disease risk. Eggs are recognized as a functional food that contain a variety of bioactive compounds that can influence pro- and anti-inflammatory pathways. Interestingly, the effects of egg consumption on inflammation varies across different populations, including those that are classified as healthy, overweight, metabolic syndrome, and type 2 diabetic. The following review will discuss the pro- and anti-inflammatory properties of egg components, with a focus on egg phospholipids, cholesterol, the carotenoids lutein and zeaxanthin, and bioactive proteins. The effects of egg consumption of inflammation across human populations will additionally be presented. Together, these findings have implications for population-specific dietary recommendations and chronic disease risk.

Ameliorative effects of lutein on non-alcoholic fatty liver disease in rats

AIM: To investigate the therapeutic effects of lutein against non-alcoholic fatty liver disease (NAFLD) and the related underlying mechanism.

METHODS: After 9 d of acclimation to a constant temperature-controlled room (20 °C-22 °C) under 12 h light/dark cycles, male Sprague-Darley rats were randomly divided into two groups and fed a standard commercial diet (n = 8) or a high-fat diet (HFD) (n = 32) for 10 d. Animals receiving HFD were then randomly divided into 4 groups and administered with 0, 12.5, 25, or 50 mg/kg (body weight) per day of lutein for the next 45 d. At the end of the experiment, the perinephric and abdominal adipose tissues of the rats were isolated and weighed. Additionally, serum and liver lipid metabolic condition parameters were measured, and liver function and insulin resistance state indexes were assessed. Liver samples were collected and stained with hematoxylin eosin and Oil Red O, and the expression of the key factors related to insulin signaling and lipid metabolism in the liver were detected using Western blot and real-time polymerase chain reaction analyses.

RESULTS: Our data showed that after being fed a high-fat diet for 10 d, the rats showed a significant gain in body weight, energy efficiency, and serum total cholesterol (TC) and triglyceride (TG) levels. Lutein supplementation induced fat loss in rats fed a high-fat diet, without influencing body weight or energy efficiency, and decreased serum TC and hepatic TC and TG levels. Moreover, lutein supplementation decreased hepatic levels of lipid accumulation and glutamic pyruvic transaminase content, and also improved insulin sensitivity. Lutein administration also increased the expression of key factors in hepatic insulin signaling, such as insulin receptor substrate-2, phosphatidylinositol 3-kinase, and glucose transporter-2 at the gene and protein levels. Furthermore, high-dose lutein increased the expression of peroxisome proliferators activated receptor-α and sirtuin 1, which are associated with lipid metabolism and insulin signaling.

CONCLUSION: These results demonstrate that lutein has positive effects on NAFLD via the modulation of hepatic lipid accumulation and insulin resistance.

One Egg per Day Improves Inflammation when Compared to an Oatmeal-Based Breakfast without Increasing Other Cardiometabolic Risk Factors in Diabetic Patients

There is concern that egg intake may increase blood glucose in patients with type 2 diabetes mellitus (T2DM). However, we have previously shown that eggs reduce inflammation in patients at risk for T2DM, including obese subjects and those with metabolic syndrome. Thus, we hypothesized that egg intake would not alter plasma glucose in T2DM patients when compared to oatmeal intake. Our primary endpoints for this clinical intervention were plasma glucose and the inflammatory markers tumor necrosis factor (TNF)-α and interleukin 6 (IL-6). As secondary endpoints, we evaluated additional parameters of glucose metabolism, dyslipidemias, oxidative stress and inflammation. Twenty-nine subjects, 35–65 years with glycosylated hemoglobin (HbA1c) values <9% were recruited and randomly allocated to consume isocaloric breakfasts containing either one egg/day or 40 g of oatmeal with 472 mL of lactose-free milk/day for five weeks. Following a three-week washout period, subjects were assigned to the alternate breakfast. At the end of each period, we measured all primary and secondary endpoints. Subjects completed four-day dietary recalls and one exercise questionnaire for each breakfast period. There were no significant differences in plasma glucose, our primary endpoint, plasma lipids, lipoprotein size or subfraction concentrations, insulin, HbA1c, apolipoprotein B, oxidized LDL or C-reactive protein. However, after adjusting for gender, age and body mass index, aspartate amino-transferase (AST) (p < 0.05) and tumor necrosis factor (TNF)-α (p < 0.01), one of our primary endpoints were significantly reduced during the egg period. These results suggest that compared to an oatmeal-based breakfast, eggs do not have any detrimental effects on lipoprotein or glucose metabolism in T2DM. In contrast, eggs reduce AST and TNF-α in this population characterized by chronic low-grade inflammation.

Egg consumption and risk of incident type 2 diabetes in men: the Kuopio Ischaemic Heart Disease Risk Factor Study

BACKGROUND

The prevalence of type 2 diabetes (T2D) is increasing around the world. Eggs are a major source of cholesterol, which has been associated with elevated blood glucose and an increased risk of T2D. However, there are limited and conflicting data from prospective population studies on the association between egg consumption and risk of T2D.

OBJECTIVE

We investigated the association between egg consumption and risk of incident T2D in middle-aged and older men from eastern Finland.

DESIGN

The study included 2332 men aged 42-60 y in 1984-1989 at the baseline examinations of the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study. Dietary intakes were assessed with 4-d food records at baseline. Incident T2D was assessed by self-administered questionnaires; by fasting and 2-h oral-glucose-tolerance-test blood glucose measurement at re-examination rounds 4, 11, and 20 y after baseline; and by record linkage to a hospital discharge registry and reimbursement register of diabetes medication expenses. Cox proportional hazards regression analyses were used to estimate associations with the risk of incident T2D. Associations with the metabolic risk markers at baseline and at the 4-y examinations were analyzed by ANCOVA.

RESULTS

During an average follow-up of 19.3 y, 432 men developed T2D. After adjustment for potential confounders, those in the highest compared with the lowest egg intake quartile had a 38% (95% CI: 18%, 53%; P-trend across quartiles <0.001) lower risk of incident T2D. Analyses with metabolic risk markers also suggested an inverse association with fasting plasma glucose and serum C-reactive protein but not with serum insulin. The associations between cholesterol intake and risk of T2D, plasma glucose, serum insulin, and C-reactive protein were mainly nonsignificant, especially after accounting for egg consumption.

CONCLUSION

Higher egg intake was associated with a lower risk of T2D in this cohort of middle-aged and older men.

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.

Cholesterol-induced inflammation and macrophage accumulation in adipose tissue is reduced by a low carbohydrate diet in guinea pigs

BACKGROUND/OBJECTIVES

The main objective of this study was to evaluate the effects of a high cholesterol (HC) dietary challenge on cholesterol tissue accumulation, inflammation, adipocyte differentiation, and macrophage infiltration in guinea pigs. A second objective was to assess whether macronutrient manipulation would reverse these metabolic alterations.

MATERIALS/METHODS

Male Hartley guinea pigs (10/group) were assigned to either low cholesterol (LC) (0.04g/100g) or high cholesterol (HC) (0.25g/100g) diets for six weeks. For the second experiment, 20 guinea pigs were fed the HC diet for six weeks and then assigned to either a low carbohydrate (CHO) diet (L-CHO) (10% energy from CHO) or a high CHO diet (H-CHO) (54% CHO) for an additional six weeks.

RESULTS

Higher concentrations of total (P < 0.005) and free (P < 0.05) cholesterol were observed in both adipose tissue and aortas of guinea pigs fed the HC compared to those in the LC group. In addition, higher concentrations of pro-inflammatory cytokines in the adipose tissue (P < 0.005) and lower concentrations of anti-inflammatory interleukin (IL)-10 were observed in the HC group (P < 0.05) compared to the LC group. Of particular interest, adipocytes in the HC group were smaller in size (P < 0.05) and showed increased macrophage infiltration compared to the LC group. When compared to the H-CHO group, lower concentrations of cholesterol in both adipose and aortas as well as lower concentrations of inflammatory cytokines in adipose tissue were observed in the L-CHO group (P < 0.05). In addition, guinea pigs fed the L-CHO exhibited larger adipose cells and lower macrophage infiltration compared to the H-CHO group.

CONCLUSIONS

The results of this study strongly suggest that HC induces metabolic dysregulation associated with inflammation in adipose tissue and that L-CHO is more effective than H-CHO in attenuating these detrimental effects.

Microalgal carotenoids: beneficial effects and potential in human health

Microalgae are huge natural sources of high-value compounds with health-promoting properties. The carotenoids derived from microalgae have significant antioxidant and anti-inflammatory effects, which allow them to provide health benefits. In this article, the bioactivities of microalgal carotenoids are reviewed. Emphasis is placed on astaxanthin, a ketocarotenoid with extraordinary potential for protecting against a wide range of diseases.