Inhibition of LDL oxidation by cocoa

Structural, dynamic, and hydration properties of quercetin and its aggregates in solution

Quercetin is a flavonoid present in the human diet with multiple health benefits. Quercetin solutions are inhomogeneous even at very low concentrations due to quercetin's tendency to aggregate. We simulate, using molecular dynamics, three systems of quercetin solutions: infinite dilution, 0.22 M, and 0.46 M. The systems at the two highest concentrations represent regions of the quercetin aggregates, in which the concentration of this molecule is unusually high. We study the behavior of this molecule, its aggregates, and the modifications in the surrounding water. In the first three successive layers of quercetin hydration, the density of water and the hydrogen bonds formations between water molecules are smaller than that of bulk. Quercetin has a hydrophilic surface region that preferentially establishes donor hydrogen bonds with water molecules with relative frequencies from 0.12 to 0.46 at infinite dilution. Also, it has two hydrophobic regions above and below the planes of its rings, whose first hydration layers are further out from quercetin (≈0.3 Å) and their water molecules do not establish hydrogen bonds with it. Water density around the hydrophobic regions is smaller than that of the hydrophilic. Quercetin molecules aggregate inπ-stacking configurations, with a distance of ≈0.37 nm between the planes of their rings, and form bonds between their hydroxyl groups. The formation of quercetin aggregates decreases the hydrogen bonds between quercetin and the surrounding water and produces a subdiffusive behavior in water molecules. Quercetin has a subdiffusive behavior even at infinite dilution, which increases with the number of molecules within the aggregates and the time they remain within them.

A Novel Promising Frontier for Human Health: The Beneficial Effects of Nutraceuticals in Cardiovascular Diseases

Cardiovascular diseases (CVDs) such as hypertension, atherosclerosis, myocardial infarction, and diabetes are a significant public health problem worldwide. Although several novel pharmacological treatments to reduce the progression of CVDs have been discovered during the last 20 years, the better way to contain the onset of CVDs remains prevention. In this regard, nutraceuticals seem to own a great potential in maintaining human health, exerting important protective cardiovascular effects. In the last years, there has been increased focus on identifying natural compounds with cardiovascular health-promoting effects and also to characterize the molecular mechanisms involved. Although many review articles have focused on the individual natural compound impact on cardiovascular diseases, the aim of this manuscript was to examine the role of the most studied nutraceuticals, such as resveratrol, cocoa, quercetin, curcumin, brassica, berberine and Spirulina platensis, on different CVDs.

Effects of grape seed extract on dyslipidaemia: a systematic review and dose–response meta-analysis of randomised controlled trials

Data on the effect of grape seed extract (GSE) on lipid profiles are inconclusive. We undertook a systematic review and meta-analysis of randomised controlled clinical trials on the effect of GSE on serum lipid profiles. The online databases of PubMed, ISI Web of Science, Scopus, ProQuest, Science Direct and Embase were searched for relevant publications until March 2019, using MeSH and non-MeSH keywords. Study selection, data extraction and quality assessment were completed independently by two investigators. Meta-regression and subgroup analyses were performed to identify the source of heterogeneity. Assessment of study quality was conducted using the Jadad scale. Eleven randomised clinical trials involving 536 participants were included in the present meta-analysis. Combining effect sizes from earlier studies, we found that GSE supplementation significantly decreased serum levels of LDL-cholesterol (−0·17 mmol/l; 95 % CI −0·34, −0·01) and TAG (−0·11 mmol/l; 95 % CI −0·18, −0·05). Although no overall significant effect of GSE supplementation on circulating total- and HDL-cholesterol levels was observed, there were significant reductions in these lipids in studies with <10 weeks of intervention and those that had administered the dosages of <300 mg/d of GSE. In conclusion, GSE supplementation seems to favourably affect serum levels of LDL and TAG concentrations, but it did not affect total- and HDL-cholesterol concentrations.

Chalcogen effects on the primary antioxidant activity of chrysin and quercetin

The effect of chalcogens on the scavenging power of chrysin and quercetin antioxidants against peroxyl radicals has been investigated in lipid and aqueous solutions, using the density functional theory.

Low-density lipoprotein oxidation biomarkers in human health and disease and effects of bioactive compounds

Based on the significance of oxidized low-density lipoprotein (LDL) in health and disease, this review focuses on human studies addressing oxidation of LDL, including three lines of biomarkers, (i) ex vivo LDL resistance to oxidation, a "challenge test" model, (ii) circulating oxidized LDL, indicating the "current in vivo status", and (iii) autoantibodies against oxidized LDL as fingerprints of an immune response to oxidized LDL, along with circulating oxysterols and 4-hydroxynonenal as biomarkers of lipid peroxidation. Lipid peroxidation and oxidized LDL are hallmarks in the development of various metabolic, cardiovascular and other diseases. Changes further occur across life stages from infancy to older age as well as in athletes and smokers. Given their responsiveness to targeted nutritional interventions, markers of LDL oxidation have been employed in a rapidly growing number of human studies for more than 2 decades. There is growing interest in foods, which, besides providing energy and nutrients, exert beneficial effects on human health, such as protection of DNA, proteins and lipids from oxidative damage. Any health claim, however, needs to be substantiated by supportive evidence derived from human studies, using reliable biomarkers to demonstrate such beneficial effects. A large body of evidence has accumulated, demonstrating protection of LDL from oxidation by bioactive food compounds, including vitamins, other micronutrients and secondary plant ingredients, which will facilitate the selection of oxidation biomarkers for future human intervention studies and health claim support.

Cocoa and Dark Chocolate Polyphenols: From Biology to Clinical Applications

It is well known that cocoa and dark chocolate possess polyphenols as major constituents whose dietary consumption has been associated to beneficial effects. In fact, cocoa and dark chocolate polyphenols exert antioxidant and anti-inflammatory activities switching on some important signaling pathways such as toll-like receptor 4/nuclear factor κB/signal transducer and activator of transcription. In particular, cocoa polyphenols induce release of nitric oxide (NO) through activation of endothelial NO synthase which, in turn, accounts for vasodilation and cardioprotective effects. In the light of the above described properties, a number of clinical trials based on the consumption of cocoa and dark chocolate have been conducted in healthy subjects as well as in different categories of patients, such as those affected by cardiovascular, neurological, intestinal, and metabolic pathologies. Even if data are not always concordant, modifications of biomarkers of disease are frequently associated to improvement of clinical manifestations. Quite interestingly, following cocoa and dark chocolate ingestion, cocoa polyphenols also modulate intestinal microbiota, thus leading to the growth of bacteria that trigger a tolerogenic anti-inflammatory pathway in the host. Finally, many evidences encourage the consumption of cocoa and dark chocolate by aged people for the recovery of the neurovascular unit.

Antioxidant and antiplatelet activity by polyphenol-rich nutrients: focus on extra virgin olive oil and cocoa

Cardiovascular disease is the most common cause of death in the Western world. In the last decades nutraceutical approaches have been proposed to counteract atherosclerotic complications. In particular, polyphenols, a class of bio-active molecules prevalently contained in foods such as cocoa, fruits, vegetables, wine and tea, have been widely studied for their beneficial properties. Several epidemiological and interventional studies have shown that polyphenol-rich nutrients, as in extra virgin olive oil (EVOO) and cocoa, are associated with a risk reduction of cardiovascular events and/or modulation of cardiovascular risk factors. Definition of the mechanisms accounting for this putative cardio-protective effect is still elusive. This review focuses on the mechanisms that may be implicated in the beneficial effects of EVOO and cocoa, including down-regulation of oxidative stress and platelet aggregation, improvement of endothelial function and cardiovascular risk factor such as blood pressure, serum cholesterol and insulin sensitivity.

A single dose of dark chocolate increases parasympathetic modulation and heart rate variability in healthy subjects

ABSTRACT Objective: The aim of this study was to investigate the acute effect of a single dose of dark chocolate (70% cocoa) on blood pressure and heart rate variability. Methods: Thirty-one healthy subjects (aged 18-25 years; both sexes) were divided into two groups: 10 subjects in the white chocolate (7.4 g) group and 21 in the dark chocolate (10 g) group; measurements were performed at the university's physiology lab. An electrocardiogram measured the sympathovagal balance by spectral and symbolic analysis. Results: A single dose of dark chocolate significantly reduced systolic blood pressure and heart rate. After consuming 10 g of dark chocolate, significant increases were observed for heart rate variability, standard deviation of RR intervals standard deviation of all NN intervals, square root of the mean squared differences between adjacent normal RR intervals root mean square of successive differences, and an increase in the high frequency component in absolute values, representing the parasympathetic modulation. Conclusion: In conclusion the importance of our results lies in the magnitude of the response provoked by a single dose of cocoa. Just 10 g of cocoa triggered a significant increase in parasympathetic modulation and heart rate variability. These combined effects can potentially increase life expectancy because a reduction in heart rate variability is associated with several cardiovascular diseases and higher mortality.

Nutrigenomic Functions of PPARs in Obesogenic Environments

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that mediate the effects of several nutrients or drugs through transcriptional regulation of their target genes in obesogenic environments. This review consists of three parts. First, we summarize current knowledge regarding the role of PPARs in governing the development of white and brown/beige adipocytes from uncommitted progenitor cells. Next, we discuss the interactions of dietary bioactive molecules, such as fatty acids and phytochemicals, with PPARs for the modulation of PPAR-dependent transcriptional activities and metabolic consequences. Lastly, the effects of PPAR polymorphism on obesity and metabolic outcomes are discussed. In this review, we aim to highlight the critical role of PPARs in the modulation of adiposity and subsequent metabolic adaptation in response to dietary challenges and genetic modifications. Understanding the changes in obesogenic environments as a consequence of PPARs/nutrient interactions may help expand the field of individualized nutrition to prevent obesity and obesity-associated metabolic comorbidities.

Pentameric Procyanidins Isolated from Theobroma cacao Seeds Selectively Downregulate ErbB2 in Human Aortic Endothelial Cells

Flavonoids isolated from cocoa have biological activities relevant to oxidant defenses, vascular health, tumor suppression, and immune function. The intake of certain dietary flavonoids, along with other dietary substances such as tocopherols, ascorbate, and carotenoids, is epidemiologically associated with a reduced risk of cardiovascular disease. Flavonoids have also been shown to modulate tumor pathology in vitro and in animal models. We took advantage of the conserved sequences found in tyrosine kinases to study the influence of cocoa fractions and controls on gene expression. We report that the pentameric procyanidin (molecular weight of 1442 daltons) fraction isolated from cocoa was a potent inhibitor of tyrosine kinase ErbB2 expression, a receptor important in angiogenesis regulation. Consistent with this primary observation, the cocoa flavonoid fraction also suppressed human aortic endothelial cell (HAEC) growth and decreased expression of two tyrosine kinases responsive to ErbB2 modulation, namely VEGFR-2/KDR and MapK 11/p38β2. These inhibitory effects were observed when HAECs were treated with the flavonol fraction (molecular weight 280 daltons) isolated from cocoa, which comprise the structural subunits from which the procyanidin flavonoid subclass is biosynthetically constructed. Down-regulation of ErbB2 and inhibition of HAEC growth by cocoa procyanidins may have several downstream implications, including reduced vascular endothelial growth factor (VEGF) activity and angiogenic activity associated with tumor pathology. These results suggest specific dietary flavonoids are capable of selectively inhibiting ErbB2 and therefore may offer important insight into the design of therapeutic agents that target tumors overexpressing ErbB2.

Cocoa Flavanol Intake and Biomarkers for Cardiometabolic Health: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Cocoa flavanols may improve cardiometabolic health. Evidence from small short-term randomized clinical trials (RCTs) remains inconsistent, and large long-term RCTs testing the efficacy of cocoa flavanols are still lacking.

OBJECTIVE

We performed a systematic review and meta-analysis of RCTs to quantify the effect of cocoa flavanol intake on cardiometabolic biomarkers.

METHODS

We searched PubMed, Web of Science, and the Cochrane Library for RCTs that evaluated the effects of cocoa flavanols on biomarkers relevant to vascular disease pathways among adults. Data were extracted following a standardized protocol. We used DerSimonian and Laird random-effect models to compute the weighted mean differences (WMDs) and 95% CIs. We also examined potential modification by intervention duration, design, age, sex, comorbidities, and the form and amount of cocoa flavanol intake.

RESULTS

We included 19 RCTs that comprised 1131 participants, and the number of studies for a specific biomarker varied. The amount of cocoa flavanols ranged from 166 to 2110 mg/d, and intervention duration ranged from 2 to 52 wk. Cocoa flavanol intake significantly improved insulin sensitivity and lipid profile. The WMDs between treatment and placebo were -0.10 mmol/L (95% CI: -0.16, -0.04 mmol/L) for total triglycerides, 0.06 mmol/L (95% CI: 0.02, 0.09 mmol/L) for HDL cholesterol, -2.33 μIU/mL (95% CI: -3.47, -1.19 μIU/mL) for fasting insulin, -0.93 (95% CI: -1.31, -0.55) for the homeostatic model assessment of insulin resistance, 0.03 (95% CI: 0.01, 0.05) for the quantitative insulin sensitivity check index, 2.54 (95% CI: 0.63, 4.44) for the insulin sensitivity index, -0.83 mg/dL (95% CI: -0.88, -0.77 mg/dL) for C-reactive protein, and 85.6 ng/mL (95% CI: 16.0, 155 ng/mL) for vascular cell adhesion molecule 1. No significant associations were found for other biomarkers. None of the modifiers seemed to qualitatively modify the effects of cocoa flavanol intake.

CONCLUSIONS

Our study suggests that cocoa flavanol intake has favorable effects on select cardiometabolic biomarkers among adults. These findings support the need for large long-term RCTs to assess whether cocoa flavanol intake reduces the risk of diabetes and cardiovascular events.

Review: Health Effects of Cocoa Flavonoids

Flavonoids are phenolic substances widely found in fruits and vegetables. Many epidemiological studies associate the ingestion of flavonoids with a reduced risk of cardiovascular disease and certain types of cancer. These effects are due to the physiological activity of flavonoids in the reduction of oxidative stress, inhibiting low-density lipoproteins (LDL) oxidation and platelet aggregation, acting as vasodilators in blood vessels, inhibiting the adherence of monocytes to the vascular endothelium, promoting fibrinolysis, acting as immunomodulators and anti-inflammatory agents and as inhibitors in the different phases of tumour process. Cocoa is an important source of polyphenols, which comprise 12-18% of its total weight on dry basis; the major phenolic compounds are epicatechin, proanthocyanidins and cate-chin. The levels of flavonoids contained are higher than the ones founds in apples, onions or wine, foods known for their high amount of phenolic compounds. Cocoa and cocoa products are important sources of flavonoids in our diet. In the Dutch population chocolate contributes up to 20% of the total flavonoid intake in adults, and in children the percentage is even higher. The bioavailability of these compounds depends on other food constituents, and their interaction with the food matrix. This article reviews current evidence on the health effects of cocoa flavonoids in our diet. The compiled data supports the premise that the consumption of cocoa flavonoids is beneficial to human health.

Habitual chocolate consumption and the risk of incident heart failure among healthy men and women

BACKGROUND

We aimed to examine the association between chocolate intake and the risk of incident heart failure in a UK general population. We conducted a systematic review and meta-analysis to quantify this association.

METHODS AND RESULTS

We used data from a prospective population-based study, the European Prospective Investigation into Cancer (EPIC)-Norfolk cohort. Chocolate intake was quantified based on a food frequency questionnaire obtained at baseline (1993-1997) and incident heart failure was ascertained up to March 2009. We supplemented the primary data with a systematic review and meta-analysis of studies which evaluated risk of incident heart failure with chocolate consumption. A total of 20,922 participants (53% women; mean age 58 ± 9 years) were included of whom 1101 developed heart failure during the follow up (mean 12.5 ± 2.7 years, total person years 262,291 years). After adjusting for lifestyle and dietary factors, we found 19% relative reduction in heart failure incidence in the top (up to 100 g/d) compared to the bottom quintile of chocolate consumption (HR 0.81 95%CI 0.66-0.98) but the results were no longer significant after controlling for comorbidities (HR 0.87 95%CI 0.71-1.06). Additional adjustment for potential mediators did not attenuate the results further. We identified five relevant studies including the current study (N = 75,408). The pooled results showed non-significant 19% relative risk reduction of heart failure incidence with higher chocolate consumption (HR 0.81 95%CI 0.66-1.01).

CONCLUSIONS

Our results suggest that higher chocolate intake is not associated with subsequent incident heart failure.

Cocoa polyphenols and fiber modify colonic gene expression in rats

Purpose

Cocoa intake has been associated with health benefits, improving cardiovascular function and metabolism, as well as modulating intestinal immune function. The aim of this study was to take an in-depth look into the mechanisms affected by the cocoa intake by evaluating the colonic gene expression after nutritional intervention, and to ascertain the role of the fiber of cocoa in these effects.

Methods

To achieve this, Wistar rats were fed for 3 weeks with either a reference diet, a diet containing 10 % cocoa (C10), a diet based on cocoa fiber (CF) or a diet containing inulin (I). At the end of the study, colon was excised to obtain the RNA to evaluate the differential gene expression by microarray. Results were validated by RT-PCR.

Results

The C10 group was the group with most changes in colonic gene expression, most of them down-regulated but a few in common with the CF diet. The C10 diet significantly up-regulated the expression of Scgb1a1 and Scnn1 g and down-regulated Tac4, Mcpt2, Fcer1a and Fabp1 by twofold, most of them related to lipid metabolism and immune function. The CF and I diets down-regulated the expression of Serpina10 and Apoa4 by twofold. Similar patterns of expression were found by PCR.

Conclusion

Most of the effects attributed to cocoa consumption on genes related to the immune system (B cell and mast cell functionality) and lipid metabolism in the colon tissue were due not only to its fiber content, but also to the possible contribution of polyphenols and other compounds.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-016-1230-0) contains supplementary material, which is available to authorized users.

Human Sperm Quality and Metal Toxicants: Protective Effects of some Flavonoids on Male Reproductive Function

Background

Metals can cause male infertility through affection of spermatogenesis and sperm quality. Strong evidences confirm that male infertility in metal-exposed humans is mediated via various mechanisms such as production of reactive oxygen species (ROS). Flavonoids have antioxidant and metal chelating properties which make them suitable candidates for neutralizing adverse effects of metals on semen quality. In the current study, we have evaluated the effects of five types of flavonoids (rutin, naringin, kaempferol, quercetin, and catechin) on recovery of sperm motility and prevention of membrane oxidative damage from aluminum chloride (AlCl₃), cadmium chloride (CdCl₂), and lead chloride (PbCl₄).

Materials and Methods

In this experimental study, motility and lipid peroxidation of metalexposed sperm was investigated in the presence of different concentrations of five kinds of flavonoids. Malondialdehyde (MDA) production was assessed as a lipid peroxidation marker.

Results

Aluminum chloride (AlCl₃), cadmium chloride (CdCl₂), and lead chloride (PbCl₄) diminished sperm motility. Treatment of metal-exposed sperm with rutin, naringin, and kaempferol attenuated the negative effects of the metals on sperm motility. Quercetin and catechin decreased the motility of metal-exposed sperm.

Conclusion

Based on the MDA production results, only AlCl₃ significantly induced lipid peroxidation. Treatment with rutin, naringin, and kaempferol significantly decreased MDA production.

Effects of dietary Corinthian currants (Vitis vinifera L., var. Apyrena) on atherosclerosis and plasma phenolic compounds during prolonged hypercholesterolemia in New Zealand White rabbits

Corinthian currants are a rich source of phenolic compounds, which are known to exert beneficial effects on cardiovascular disease. The hypothesis tested is whether dietary supplementation with currants attenuates atherosclerosis and affects plasma phenolics during prolonged hypercholesterolemia in rabbits. Thirty New Zealand White rabbits were fed one of four diets (normal and supplemented with 10% currants, with 0.5% cholesterol, and with 0.5% cholesterol plus 10% currants) for eight weeks. Plasma lipids, glucose and hepatic enzymes were determined. Individual phenolic compounds were identified and quantified in plasma during the dietary intervention. At the end of the study, histological examinations of aorta and liver were performed. The high-cholesterol diet resulted in hypercholesterolemia and oxidative stress, increased aspartate aminotransferase (AST) activity and induced aortic and hepatic lesion formation. Corinthian currant supplementation attenuated atherosclerotic lesions, maintained AST within the normal range and reduced oxidative stress without affecting glucose concentrations. The p-OH-benzoic and p-OH-phenylacetic acids predominated at high concentrations in plasma and remained almost constant during the study in the group that received the normal rabbit chow and the groups given food with added cholesterol either alone or supplemented with currants. Currant supplementation to the normal diet resulted in the reduced absorption of phenolic compounds, as revealed by the measurement of their plasma metabolites, suggesting a regulatory mechanism at the gut level under normal conditions.

The relationship between phenolic compounds from diet and microbiota: impact on human health

The human intestinal tract is home to a complex microbial community called microbiota.

Evaluation of antiradical activity of different cocoa and chocolate products: relation with lipid and protein composition

Chocolate antioxidant properties are often claimed; however, they are frequently different from the parent natural sources due to the industry or artisan transformation. In particular, antioxidant property of chocolate and cocoa are not adequately taken into consideration by consumers who normally make use of this food just for its flavor and taste properties. In this study, we have investigated the antioxidant capacity and total phenolic content of cocoa nibs, cocoa masses, and corresponding chocolate bars with different percentages of cocoa from different origins. The antioxidant capacity of the different samples was measured by two different assays [1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) and ferric reducing antioxidant of potency (FRAP) tests]. The Folin-Ciocalteu reagent was used to assess the total phenolic content. The masses showed a higher antioxidant power than the nibs, and this has been attributed to the fact that in the nibs is still present the lipid part, which will form the cocoa butter. The influence of milk, whey, and soy proteins was also investigated. Our results showed that the extra dark cocoa bar, 100% cocoa chocolate, is the best in terms of total polyphenol content and in terms of antioxidant capacity according to the DPPH and FRAP tests. In addition, the bars of organic dark chocolate 80%, dark Tanzania 80%, and Trinidad 80% products are well performing in all respects. As highlighted by us, the antiradical properties of cocoa products are higher than many antioxidant supplements in tablets.

Pleiotropic preventive effects of dietary polyphenols in cardiovascular diseases

Polyphenols are common constituents of the diet, and research on their health benefits has developed quickly over the past few years. Our purpose is to review recent findings highlighting daily dietary polyphenol intake and the diverse function of polyphenols and their possible relationships to cardiovascular disease (CVD). Several cohort studies have reported an inverse relationship between the daily consumption of polyphenols and CVD risk. Many studies showed that beverages could be a large source of polyphenols. Our previous findings provide that Japanese people intake polyphenols mainly from beverages, especially coffee and green tea (in descending order of polyphenol content). Many kinds of polyphenols act as an antioxidant against low-density lipoprotein oxidation, which is known to promote atherosclerosis. Recent accumulating evidence suggests that dietary polyphenols could exert their cardioprotective actions through their potential to improve metabolic disorder and vascular inflammation. These findings raise the possibility that polyphenols have a wide variety of roles in the intestine, liver and vascular tissue. In addition to identifying mechanisms of polyphenol bioactivity by basic research, much more epidemiological and clinical evidence linking reduced cardiovascular risk with dietary polyphenols intake are needed.

Antioxidant activity and flavonoid content of Clusia fluminensis Planch. & Triana

Clusia fluminensis Planch. & Triana (Clusiaceae Lindl.) is a native species found in regions of high luminosity and water restriction. The aim of this study was to evaluate the antioxidant activity of Clusia fluminensis crude extracts through the scavenging of the stable free radical DPPH, and the determination of flavones and flavonols content in these extracts. The fruit acetonic extract showed the lowest EC(50) value (2.71 ± 0.34 g extract / g DPPH), the lowest percentage of remaining DPPH at the concentrations of 125 and 250 µg/mL (about 4% in both), and also the greatest percentage of flavones and flavonols (13.93 ± 0.21 %). Statistical analysis suggests a positive correlation between the presence of flavonoids and the antioxidant activity of this extract. From the obtained results it can be inferred that the acetonic extract of C. fluminensis fruits is an interesting target for the search of substances with antioxidant activity, especially flavonoids.

Bioactive compounds and antioxidant activity in fruits of clone and ungrafted genotypes of yellow mombin tree

Yellow mombin is a fruit tree that grows spontaneously in the Semi-Arid Northeastern Brazil. Its fruits are still extractively exploited. The pulp of yellow mombin fruit stands out regarding the commercial aspect due to the characteristic flavor and aroma felt when consumed in diverse ways. This study aimed to evaluate the presence of bioactive compounds, total extractable polyphenols, and antioxidant activity of yellow mombin fruits (Spondias mombin, L.), from clone and ungrafted genotypes. The fruits were harvested at commercial maturity from twelve yellow mombin tree genotypes from an experimental orchard located at the municipality of Joao Pessoa, Paraíba, Brazil, and evaluated for chlorophyll, carotenoids, yellow flavonoids, total extractable polyphenols, and antioxidant activity, which was measured by the β-carotene/linoleic acid method. The antioxidant activity showed a percentage of inhibition of oxidation higher than 75% for all genotypes evaluated at the time of 120 minutes. The fruits from clone genotypes showed a higher percentage of antioxidant activity.

Phenolic compounds and antioxidant activity of bulb extracts of six Lilium species native to China

Lily (Lilium) is used as an important edible and medical plant species with a vague taxonomic classification and a long history in China. Bulbs of six Lilium species (L. regale, L. concolor, L. pumilum, L. leucanthum, L. davidii var. unicolor and L. lancifolium) native to China were investigated with a view to their exploitation as a potential source of natural antioxidants due to their phenolic composition and dietary antioxidant potential. The results showed that all bulb extracts exhibited strong antioxidant activities, which generally correlated positively with the total phenolic contents (r = 0.68 to 0.94), total flavonoid contents (r = 0.51 to 0.89) and total flavanol contents (r = 0.54 to 0.95). High-performance liquid chromatography (HPLC) analysis revealed that rutin and kaempferol were the major phenolic components in the extracts. Hierarchical cluster analysis showed that L. regale belonged to the group with high phenolic content and strong antioxidant power. L. concolor and L. pumilum were arranged in one group characterized by moderate phenolic content and antioxidant capacity, while L. leucanthum, L. davidii var. unicolor and L. lancifolium were clustered in the third group with low phenolic content and weak antioxidant activity. These strongly suggest that lily bulbs may serve as a potential source of natural antioxidant for food and pharmaceutical applications.

Impact of fermentation, drying, roasting and Dutch processing on flavan-3-ol stereochemistry in cacao beans and cocoa ingredients

This paper reports a systematic study of the level of flavan-3-ol monomers during typical processing steps as cacao beans are dried, fermented and roasted and the results of Dutch-processing. Methods have been used that resolve the stereoisomers of epicatechin and catechin. In beans harvested from unripe and ripe cacao pods, we find only (-)-epicatechin and (+)-catechin with (-)-epicatechin being by far the predominant isomer. When beans are fermented there is a large loss of both (-)-epicatechin and (+)-catechin, but also the formation of (-)-catechin. We hypothesize that the heat of fermentation may, in part, be responsible for the formation of this enantiomer. When beans are progressively roasted at conditions described as low, medium and high roast conditions, there is a progressive loss of (-)-epicatechin and (+)-catechin and an increase in (-)-catechin with the higher roast levels. When natural and Dutch-processed cacao powders are analyzed, there is progressive loss of both (-)-epicatechin and (+)-catechin with lesser losses of (-)-catechin. We thus observe that in even lightly Dutch-processed powder, the level of (-)-catechin exceeds the level of (-)-epicatechin. The results indicate that much of the increase in the level of (-)-catechin observed during various processing steps may be the result of heat-related epimerization from (-)-epicatechin. These results are discussed with reference to the reported preferred order of absorption of (-)-epicatechin > (+)-catechin > (-)-catechin. These results are also discussed with respect to the balance that must be struck between the beneficial impact of fermentation and roasting on chocolate flavor and the healthful benefits of chocolate and cocoa powder that result in part from the flavan-3-ol monomers.

Sweet potato (Ipomoea batatas L.) leaves suppressed oxidation of low density lipoprotein (LDL) in vitro and in human subjects

Sweet potato (Ipomoea batatas L.) leaves are consumed as vegetables around the world, especially in Southeast Asia. The aim of this study was to investigate the inhibitory effect of sweet potato leaves on low-density lipoprotein oxidation in vitro and in human subjects. We compared the antioxidant activity of 8 kinds of sweet potato leaves. Every sweet potato leaf had high radical scavenging activity and prolonged a lag time for starting low-density lipoprotein oxidation in vitro. We found that sweet potato leaves contained abundant polyphenol compounds and the radical scavenging activity and prolongation rate of lag time were highly correlated with total polyphenol content. We also confirmed that thiobarbituric acid reactive substances production was increased in endothelial cell-mediated low-density lipoprotein oxidation, which was decreased by treatment with sweet potato leaves. We further measured the low-density lipoprotein oxidizability in 13 healthy volunteers after their intake of 18 g of “Suioh”, raw sweet potato leaves. “Suioh” prolonged a lag time for starting low-density lipoprotein oxidation and decreased low-density lipoprotein mobility. These results suggest that sweet potato leaves have antioxidant activity leading to the suppression of low-density lipoprotein oxidation.

The effect of acute pre-exercise dark chocolate consumption on plasma antioxidant status, oxidative stress and immunoendocrine responses to prolonged exercise

PURPOSE

Acute antioxidant supplementation may modulate oxidative stress and some immune perturbations that typically occur following prolonged exercise. The aims of the present study were to examine the effects of acutely consuming dark chocolate (high polyphenol content) on plasma antioxidant capacity, markers of oxidative stress and immunoendocrine responses to prolonged exercise.

METHODS

Fourteen healthy men cycled for 2.5 h at ~60% maximal oxygen uptake 2 h after consuming 100 g dark chocolate (DC), an isomacronutrient control bar (CC) or neither (BL) in a randomised-counterbalanced design.

RESULTS

DC enhanced pre-exercise antioxidant status (P = 0.003) and reduced by trend (P = 0.088) 1 h post-exercise plasma free [F₂-isoprostane] compared with CC (also, [F₂-isoprostane] increased post-exercise in CC and BL but not DC trials). Plasma insulin concentration was significantly higher pre-exercise (P = 0.012) and 1 h post-exercise (P = 0.026) in the DC compared with the CC trial. There was a better maintenance of plasma glucose concentration on the DC trial (2-way ANOVA trial × time interaction P = 0.001), which decreased post-exercise in all trials but was significantly higher 1 h post-exercise (P = 0.039) in the DC trial. There were no between trial differences in the temporal responses (trial × time interactions all P > 0.05) of hypothalamic-pituitary-adrenal axis stress hormones, plasma interleukin-6, the magnitude of leukocytosis and neutrophilia and changes in neutrophil function.

CONCLUSION

Acute DC consumption may affect insulin, glucose, antioxidant status and oxidative stress responses, but has minimal effects on immunoendocrine responses, to prolonged exercise.

Prebiotic evaluation of cocoa-derived flavanols in healthy humans by using a randomized, controlled, double-blind, crossover intervention study

BACKGROUND

The absorption of cocoa flavanols in the small intestine is limited, and the majority of the flavanols reach the large intestine where they may be metabolized by resident microbiota.

OBJECTIVE

We assessed the prebiotic potential of cocoa flavanols in a randomized, double-blind, crossover, controlled intervention study.

DESIGN

Twenty-two healthy human volunteers were randomly assigned to either a high-cocoa flavanol (HCF) group (494 mg cocoa flavanols/d) or a low-cocoa flavanol (LCF) group (23 mg cocoa flavanols/d) for 4 wk. This was followed by a 4-wk washout period before volunteers crossed to the alternant arm. Fecal samples were recovered before and after each intervention, and bacterial numbers were measured by fluorescence in situ hybridization. A number of other biochemical and physiologic markers were measured.

RESULTS

Compared with the consumption of the LCF drink, the daily consumption of the HCF drink for 4 wk significantly increased the bifidobacterial (P < 0.01) and lactobacilli (P < 0.001) populations but significantly decreased clostridia counts (P < 0.001). These microbial changes were paralleled by significant reductions in plasma triacylglycerol (P < 0.05) and C-reactive protein (P < 0.05) concentrations. Furthermore, changes in C-reactive protein concentrations were linked to changes in lactobacilli counts (P < 0.05, R(2) = -0.33 for the model). These in vivo changes were closely paralleled by cocoa flavanol-induced bacterial changes in mixed-batch culture experiments.

CONCLUSION

This study shows, for the first time to our knowledge, that consumption of cocoa flavanols can significantly affect the growth of select gut microflora in humans, which suggests the potential prebiotic benefits associated with the dietary inclusion of flavanol-rich foods. This trial was registered at clinicaltrials.gov as NCT01091922.

Antioxidant effects of cocoa and cocoa products ex vivo and in vivo: is there evidence from controlled intervention studies?

PURPOSE OF REVIEW

There is strong epidemiological evidence that the consumption of flavanol-rich cocoa products contributes to the prevention of cardiovascular diseases mediated partly by their strong antioxidant effects. We reviewed the recent literature to answer the question whether this antioxidant action can be confirmed by intervention studies in healthy study participants and specific patient groups.

RECENT FINDINGS

In 19 controlled intervention studies (two in patients with cardiovascular diseases), markers of plasma antioxidant capacity and oxidative stress were analyzed after bolus and/or regular cocoa consumption. In both, healthy study participants and patients, total plasma antioxidant capacity as well as most markers of oxidative stress were not influenced by the intervention. Low-density lipoprotein oxidation ex vivo and in vivo decreased probably due to a direct beneficial effect of cocoa flavanols on lipid and protein oxidation.

SUMMARY

Recent clinical trials do not provide sufficient evidence for an essential contribution of cocoa products to the overall antioxidant defense. Any recommendations for cocoa intake within preventive and therapeutic measures are presently not reasonable.

Chocolate intake and incidence of heart failure: a population-based prospective study of middle-aged and elderly women

BACKGROUND

Randomized clinical trials have shown that chocolate intake reduces systolic and diastolic blood pressure, and observational studies have found an inverse association between chocolate intake and cardiovascular disease. The aim of this study was to investigate the association between chocolate intake and incidence of heart failure (HF).

METHODS AND RESULTS

We conducted a prospective cohort study of 31,823 women aged 48 to 83 years without baseline diabetes or a history of HF or myocardial infarction who were participants in the Swedish Mammography Cohort. In addition to answering health and lifestyle questions, participants completed a food-frequency questionnaire. Women were followed from January 1, 1998, through December 31, 2006, for HF hospitalization or death through the Swedish inpatient and cause-of-death registers. Over 9 years of follow-up, 419 women were hospitalized for incident HF (n=379) or died of HF (n=40). Compared with no regular chocolate intake, the multivariable-adjusted rate ratio of HF was 0.74 (95% CI, 0.58 to 0.95) for women consuming 1 to 3 servings of chocolate per month, 0.68 (95% CI, 0.50 to 0.93) for those consuming 1 to 2 servings per week, 1.09 (95% CI, 0.74 to 1.62) for those consuming 3 to 6 servings per week, and 1.23 (95% CI, 0.73 to 2.08) for those consuming ≥1 servings per day (P=0.0005 for quadratic trend).

CONCLUSIONS

In this population, moderate habitual chocolate intake was associated with a lower rate of HF hospitalization or death, but the protective association was not observed with intake of ≥1 servings per day.

Cocoa, chocolate, and cardiovascular disease

A significant body of evidence demonstrates that diets rich in fruits and vegetables promote health and attenuate, or delay, the onset of various diseases, including cardiovascular disease, diabetes, certain cancers, and several other age-related degenerative disorders. The concept that moderate chocolate consumption could be part of a healthy diet has gained acceptance in past years based on the health benefits ascribed to selected cocoa components. Specifically, cocoa as a plant and chocolate as food contain a series of chemicals that can interact with cell and tissue components, providing protection against the development and amelioration of pathological conditions. The most relevant effects of cocoa and chocolate have been related to cardiovascular disease. The mechanisms behind these effects are still under investigation. However, the maintenance or restoration of vascular NO production and bioavailability and the antioxidant effects are the mechanisms most consistently supported by experimental data. This review will summarize the most recent research on the cardiovascular effects of cocoa flavanols and related compounds.

Acute effects of vinegar intake on some biochemical risk factors of atherosclerosis in hypercholesterolemic rabbits

Background

Exaggerated postprandial spikes in blood glucose and lipids induce proportional increases in oxidative stress, which acutely trigger impairment endothelial, inflammation and increased risk of future cardiovascular events. In this research, we have investigated acute effects of vinegar intake on some of the biochemical atherosclerosis risk factors in high cholesterol fed rabbits to see if we can find a probable protective value for it.

Methods

The rabbits were randomly divided into four groups: normal diet, high cholesterol diet (%1cholesterol), %1 cholesterol with 5 ml vinegar (low dose), %1 cholesterol with 10 ml vinegar (high dose). After fasting for 12-15 hours, blood samples were taken to determine baseline values. Three hours after feeding, blood samples were collected again to investigate acute effects of vinegar intake on the measured factors.

Results

Using high-dose vinegar with cholesterolemic diet caused significant reduce in LDL-cholesterol (LDL-C), oxidized-LDL (ox-LDL), malondialdehyde (MDA), total cholesterol (TC) and apolipoprotein B (ApoB) in comparison with hypercholesterolemic diet. Consumption low-dose vinegar with cholesterolemic diet induced a significant decrease in fibrinogen and glucose compared to hypercholesterolemic diet. Level of serum nitrite, nitrate, triacylglycerol (TAG), HDL-cholesterol (HDL-C), apolipoprotein A (ApoA), serum glutamic pyruvic transaminase (SGPT), serum glutamic oxaloacetate transaminase (SGOT) and C-reactive protein (CRP) were not significantly difference in low and high doses vinegar with cholesterolemic diet compared to hypercholesterolemic diet. A significant difference was observed for LDL-C, ApoB100 and TC between low and high doses vinegar.

Conclusion

This study suggest that vinegar, might have some acute effects on biochemical risk factors of atherosclerosis and a probable protective value can be considered for its postprandial use.

Polyphenols from cocoa and vascular health-a critical review

Cocoa is a rich source of dietary polyphenols. In vitro as well as cell culture data indicate that cocoa polyphenols may exhibit antioxidant and anti-inflammatory, as well as anti-atherogenic activity. Several molecular targets (e.g., nuclear factor kappa B, endothelial nitric oxide synthase, angiotensin converting enzyme) have been recently identified which may partly explain potential beneficial cardiovascular effects of cocoa polyphenols. However cocoa polyphenol concentrations, as used in many cell culture studies, are not physiologically achievable. Bioavailability studies indicate that plasma concentrations of cocoa polyphenols following dietary intake are low and in the nanomolar range. Human studies regarding the effect of cocoa polyphenols on vascular health are often underpowered and lack a rigorous study design. If dietary cocoa polyphenol intake is due to chocolate its high energy content needs to be taken into account. In order to determine potential health benefits of cocoa polyphenols large scale, long term, randomized, placebo controlled studies, (ideally with a cross-over design) as well as prospective studies are warranted.