Antihypertensive effect of a polyphenol-rich cocoa powder industrially processed to preserve the original flavonoids of the cocoa beans

Crotalaria burhia Buch. -Ham.: a comprehensive review of its botany, traditional uses, phytochemistry, and pharmacology

Crotalaria burhia (Family: Fabaceae) is an important medicinal plant widely distributed in arid parts of the world, including Pakistan, India, and Afghanistan. This plant has enormous ethnobotanical values and is used to treat various common ailments such as swelling, infections, cancer, hydrophobia, pain and skin diseases. Moreover, it is also utilised as food for goats, to make sheds for animals and as a suitable soil binder. This review article is an attempt to analyse critically and to provide updated and categorised information about C. burhia including comprehensive knowledge of the botanical description, traditional/folklore uses, phytochemistry, pharmacological/biological potential, and to facilitate scientific basis for future work. The phytochemical studies (qualitative and quantitative) on C. burhia have indicated the presence of important phytochemical classes, namely alkaloids, flavonoids, glycosides, saponins, phenolics, tannins, steroids, and terpenoids. Pharmacological studies such as anti-inflammatory/analgesic, antioxidant, anti-microbial, anti-tumour, anti-nociceptive, enzyme inhibition, and termiticidal activities were reported from different parts of this plant. Most of the bioassays from this plant have been done on the crude extract. Minimal information about the phytochemicals (responsible for biological activities), except a few compounds has been reported. The potential chemical compounds may need to be purified and tested for the biological potential from isolated compounds in future.

Natural Products to Promote Vascular Health

Maintaining good vascular health is a major component in healthy ageing as it reduces the risk of cardiovascular diseases. Endothelial dysfunction, in particular, is a key mechanism in the development of major cardiovascular diseases including hypertension, atherosclerosis and diabetes. Recently, endothelial senescence has emerged as a pivotal early event in age-related endothelial dysfunction. Endothelial function is characterized by an imbalance between the endothelial formation of vasoprotective mechanisms, including the formation of nitric oxide (NO) and endothelium-dependent hyperpolarization responses, and an increased level of oxidative stress involving several pro-oxidant enzymes such as NADPH oxidases and, often also, the appearance of cyclooxygenase-derived vasoconstrictors. Pre-clinical studies have indicated that natural products, in particular several polyphenol-rich foods, can trigger activating pathways in endothelial cells promoting an increased formation of NO and endothelium-dependent hyperpolarization. In addition, some can even exert beneficial effects on endothelial senescence. Moreover, some of these products have been associated with the prevention and/or improvement of established endothelial dysfunction in several experimental models of cardiovascular diseases and in humans with cardiovascular diseases. Therefore, intake of certain natural products, such as dietary and plant-derived polyphenol-rich products, appears to be an attractive approach for a healthy vascular system in ageing.

Potential of Anthocyanin-rich Products to Prevent and Improve Endothelial Function and Senescence: Focus on Anthocyanins

Endothelial dysfunction is a pivotal early event in the development of major cardiovascular diseases including hypertension, atherosclerosis, diabetes, and aging. The alteration of the endothelial function is often triggered by an imbalance between the endothelial formation of vasoprotective factors, including nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH), and vasocontracting factors, such as arachidonic acid-derived mediators generated by cyclooxygenases, and an increased level of oxidative stress. Recently, endothelial senescence was reported to be an early trigger of endothelial dysfunction. Preclinical studies indicate that polyphenol-rich food, including anthocyanin-rich products, can activate pathways promoting an increased formation of vasoprotective factors and can prevent the induction of endothelial dysfunction in endothelial cells and isolated blood vessels. Similarly, intake of anthocyanin-rich products has been associated with the prevention and/or the improvement of an endothelial dysfunction in several experimental models of cardiovascular diseases, including physiological aging. Moreover, clinical data indicate that polyphenol-rich and anthocyanin-rich products can improve endothelial function and vascular health in humans with cardiovascular diseases. The present review will discuss both experimental and clinical evidence indicating that several polyphenol-rich foods and natural products, and especially anthocyanin-rich products, can promote endothelial and vascular health, as well as the underlying mechanisms.

Extraction, Identification, and Quantification of Polyphenols from the Theobroma cacao L. Fruit: Yield vs. Environmental Friendliness

The cacao fruit is a rich source of polyphenols, including flavonoids and phenolic acids, which possess significant health benefits. The accurate identification and quantification of these bioactive compounds extracted from different parts of the cacao fruit, such as pods, beans, nibs, and cacao shells, require specific treatment conditions and analytical techniques. This review presents a comprehensive comparison of extraction processes and analytical techniques used to identify and quantify polyphenols from various parts of the cacao fruit. Additionally, it highlights the environmental impact of these methods, exploring the challenges and opportunities in selecting and utilizing extraction, analytical, and impact assessment techniques, while considering polyphenols' yield. The review aims to provide a thorough overview of the current knowledge that can guide future decisions for those seeking to obtain polyphenols from different parts of the cacao fruit.

Effect of Cocoa Beverage and Dark Chocolate Consumption on Blood Pressure in Those with Normal and Elevated Blood Pressure: A Systematic Review and Meta-Analysis

Cocoa is a major dietary source of polyphenols, including flavanols, which have been associated with reduced blood pressure (BP). While earlier systematic reviews and meta-analyses have shown significant effects of cocoa consumption on systolic BP, limitations include small sample sizes and study heterogeneity. Questions regarding food matrix and dose of polyphenols, flavanols, or epicatechins remain. This systematic review and meta-analysis aimed to investigate the effects of ≥2 weeks of cocoa consumption as a beverage or dark chocolate in those with normal or elevated (< or ≥130 mmHg) systolic BP measured in the fasted state or over 24-h. A systematic search conducted on PubMed and Cochrane Library databases up to 26 February 2022 yielded 31 suitable articles. Independent of baseline BP, cocoa consumption for ≥2 weeks was associated with reductions in systolic and diastolic BP (p < 0.05, all). Compared with cocoa, chocolate lowered the weighted mean of resting systolic BP (−3.94 mmHg, 95% CI [−5.71, −2.18]) more than cocoa beverage (−1.54 mmHg, 95% CI [−3.08, 0.01]). When the daily dose of flavanols was ≥900 mg or of epicatechin ≥100 mg, the effect was greater. Future, adequately powered studies are required to determine the optimal dose for a clinically significant effect.

Winery by-products as a valuable source for natural antihypertensive agents

Hypertension (HTN) is one of the leading causes of death in the world. Agri-food by-products are emerging as a novel source of natural antihypertensive agents allowing for their valorization and making food and agricultural industries more environmentally friendly. In this regard, wine making process generates large amounts of by-products rich in phenolic compounds that have shown potential to exert several beneficial effects including antihypertensive properties. The aim of this study was to review the blood pressure-lowering effects of winery by-products. In addition, molecular mechanisms involved in their bioactivity were also evaluated. Among the winery by-products, grape seed extracts have widely shown antihypertensive properties in both animal and human studies. Moreover, recent evidence suggests that grape stem, skin and pomace and wine lees may also have great potential to manage HTN, although more studies are needed in order to confirm their potential in humans. Improvement of endothelial dysfunction and reduction of oxidative stress associated with HTN are the main mechanisms involved in the blood pressure-lowering effects of these by-products.

Influence of Freeze-Dried Phenolic-Rich Plant Powders on the Bioactive Compounds Profile, Antioxidant Activity and Aroma of Different Types of Chocolates

In this study, the blueberries (BLUB), raspberries (RASB), blackberries (BLCB), pomegranates pomace (POME) and beetroots (BEET) freeze-dried powders were used as the sources of phenolic compounds to enrich different types of chocolates, substituting a part of the sweetener. It was found that 1% addition of fruit or vegetable powders to chocolates increased the content of total phenolic compounds (flavan-3-ols, phenolic acids and anthocyanins) of enriched dark and milk chocolates compared to the control ones dependent on the powder used. Among the enriched chocolates, the chocolates with the addition of BLUB powder were characterized by the highest total polyphenol content. The highest percentage increase (approximately 80%) in the total polyphenol content was observed in MCH chocolate enriched with BLUB powder. Chocolates incorporated with BLUB, RASB, BLCB and POME powders presented a richer phenolic compound profile than control counterparts. The highest DPPH radical-scavenging capacity was exhibited by the DCH98S chocolate enriched with BEET powder. However, the DCH98ESt chocolates enriched with POME and BEET powders demonstrated the highest FRAP values. An electronic nose analysis confirmed the existence of differences between the profiles of volatile compounds of various types of chocolates enriched with fruit or vegetable powders. Thus, the enrichment of dark and milk chocolates with BLUB, RASB, BLCB, POME and BEET powders seemed to be an interesting approach to enhance bioactivity and to enrich the sensory features of various chocolate types.

Blood Pressure-Lowering Effect of Wine Lees: Dose-Response Study, Effect of Dealcoholization and Possible Mechanisms of Action

The antihypertensive effect of wine lees (WL) has been previously evidenced. In this study, the antihypertensive properties of different doses of WL were evaluated in spontaneously hypertensive rats (SHR). In addition, the blood pressure (BP)-lowering effect of dried (dealcoholized) WL powder (WLPW) and the mechanisms involved in its functionality were investigated. Furthermore, a possible hypotensive effect of WLPW was discarded in Wistar-Kyoto (WKY) rats. The administration of WL at different doses caused a dose-dependent decrease in BP of SHR up to 5.0 mL/kg bw, exhibiting the maximum decrease at 6 h post-administration. WLPW caused a greater drop in BP than WL, showing an antihypertensive effect higher and more prolonged than the drug Captopril. Moreover, the BP-lowering effect of WLPW was specific to the hypertensive state since an undesirable hypotensive effect in normotensive WKY rats was ruled out. Finally, WLPW improved oxidative stress and increased the activity of the antioxidant endogen system of SHR. These results suggest that WLPW could be used as functional ingredient for foods or nutraceuticals to ameliorate hypertension. Nevertheless, further clinical studies are needed to evaluate its long-term antihypertensive efficiency.

Chemical and flavor profile changes of cocoa beans (Theobroma cacao L.) during primary fermentation

This survey reports for the first time the changed of quality of fermented cocoa (Theobroma cacao L.) beans. The quality evaluation and simultaneous detection of amino acids, flavor, procyanidin, color, fat, protein, antioxidant activity, and enthalpy were obtained for different fermentation stages of cocoa beans. The results showed that total essential amino acids contents ranged from 2.64 g/100 g to 3.68 g/100 g. A total of 88 compounds identified at the end of the fermentation belonged to alcohols, acids, esters, ketones, pyrazines, aldehydes, and terpenoids. One of the chemical groups that were present in highest abundance in the consummation treatments was acids, representing 56.04% of the total extracted area, followed by alcohols (22.95%) and ketones (9.40%). The colors of the beans in different fermentation stages were different, from deep purple to deep red-brown. Fermented cocoa beans were shown to be 53.45% and 13.51% bean butter and protein content, respectively. The value of denaturation enthalpy (ΔH) ranged from 30.4 (J/g) to 43.38 (J/g). The 3-day fermented sample had the highest ΔH (43.38 J/g). When the fermentation process was complete, the procyanidin concentration of the beans decreased, with the final yield of procyanidin at 6.2%. During fermentation, the antioxidant capacity of beans gradually reduced. The fermenting of cocoa beans had a significant effect on the quality formation. The findings of this study constitute a basis for further investigations on the quality formation of cocoa during fermentation.

Effects of Raw and Roasted Cocoa Bean Extracts Supplementation on Intestinal Enzyme Activity, Biochemical Parameters, and Antioxidant Status in Rats Fed a High-Fat Diet

The aim of the study was to analyze the influence of diet containing the polyphenol-rich material on intestinal enzyme activity, oxidative stress markers, lipid metabolism and antioxidant status of laboratory rats. The animals were fed high-fat diet supplemented with freeze-dried water extracts of raw and roasted cocoa beans of Forastero variety. The observed changes indicated the biological activity of polyphenols and other components of the prepared cocoa beans extracts (CBEs). The presence of raw and roasted CBEs in the diets diversified the activity of the enzymes of the cecal microflora of rats. Both CBEs beneficially affect the antioxidant status of the serum, even in relation to the control standard group. The experimental cocoa bean preparations showed no significant effect on the mass of rats' liver, heart, and kidneys, but varied some parameters of the antioxidant status of their organisms. The raw CBE in rats fed with the high-fat diet shows a high ability to inhibit lipid peroxidation in heart and more effectively increases hepatic reduced glutathione (GSH) concentrations compared to the roasted CBE, which did not show any significant effect. Moreover, supplementation with both CBEs significantly affects the volatile fatty acids concentration in the rats' cecum. Results of this study contribute to the evidence that dietary supplementation with raw and roasted CBEs can exert health-promoting effects, however further studies are necessary.

Improvement of the Flavanol Profile and the Antioxidant Capacity of Chocolate Using a Phenolic Rich Cocoa Powder

Chocolate is made from cocoa, which is rich in (poly)phenols that have a high antioxidant capacity and are associated with the prevention of chronic diseases. In this study, a new production process was evaluated in order to obtain a dark chocolate enriched in (poly)phenols using a cocoa powder with an improved flavanol profile. The antioxidant capacity (Oxygen Radical Absorbance Capacity (ORAC) assay) and the flavanol profile (HPLC-DAD and HPLC-FL) was determined. The analysis of the enriched chocolate showed that the total flavan-3-ols (monomers) content was 4 mg/g representing a 3-fold higher than that quantified in the conventional one. Total levels of dimers (procyanidin B1 and B2) were 2.4-fold higher in the enriched chocolate than in the conventional, with a total content of 6 mg/g. The total flavanol content (flavan-3-ols and procyanidins) in the enriched chocolate was increased by 39% compared to the conventional one which led to a 56% increase in the antioxidant capacity. The new flavanol-enriched dark chocolate is expected to provide greater beneficial effect to consumers. Moreover, the amount of flavonols provided by a single dose (ca. 200 mg per 10 g) would allow the use of a health claim on cardiovascular function, a fact of interest for the cocoa industry.

Development and Characterization of a Pilot-Scale Model Cocoa Fermentation System Suitable for Studying the Impact of Fermentation on Putative Bioactive Compounds and Bioactivity of Cocoa

Cocoa is a concentrated source of dietary flavanols—putative bioactive compounds associated with health benefits. It is known that fermentation and roasting reduce levels of native flavonoids in cocoa, and it is generally thought that this loss translates to reduced bioactivity. However, the mechanisms of these losses are poorly understood, and little data exist to support this paradigm that flavonoid loss results in reduced health benefits. To further facilitate large-scale studies of the impact of fermentation on cocoa flavanols, a controlled laboratory fermentation model system was increased in scale to a large (pilot) scale system. Raw cocoa beans (15 kg) were fermented in 16 L of a simulated pulp media in duplicate for 168 h. The temperature of the fermentation was increased from 25–55 °C at a rate of 5 °C/24 h. As expected, total polyphenols and flavanol levels decreased as fermentation progressed (a loss of 18.3% total polyphenols and 14.4% loss of total flavanols during fermentation) but some increases were observed in the final timepoints (120–168 h). Fermentation substrates, metabolites and putative cocoa bioactive compounds were monitored and found to follow typical trends for on-farm cocoa heap fermentations. For example, sucrose levels in pulp declined from >40 mg/mL to undetectable at 96 h. This model system provides a controlled environment for further investigation into the potential for optimizing fermentation parameters to enhance the flavanol composition and the potential health benefits of the resultant cocoa beans.

Influence of Diet Enriched with Cocoa Bean Extracts on Physiological Indices of Laboratory Rats

Cocoa bean is a rich source of polyphenols, mainly flavonoids which have a wide range of biological properties. The aim of the study was to determine the physiological indices of laboratory rats as a response to diets containing water extracts of raw or roasted cocoa beans of Forastero variety, as well as purified monomeric flavan-3-ols fraction isolated from them. The influence of these extracts on selected parameters was studied during 4 weeks feeding. The samples of rats feces were collected throughout the experiment and after its completion, biological samples (intestines content, blood, and organs) were retrieved individually from each rat and subjected to analyses. The observed changes in the gastrointestinal tract functioning indices and metabolism indicators, determined throughout the study and after its completion, confirm to some extent the biological activity of polyphenol extracts of cocoa beans. The differences in the results obtained for the analyzed parameters of the gastrointestinal tract revealed that the cocoa bean extracts differently affected the physicochemical properties of rats' intestines. The results indicate the beneficial effects of the applied nutrition treatment on the activity of cecal enzymes and the content of volatile fatty acids in the gut.

Cardiovascular Effects of Flavonoids

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Cardiovascular Disease (CVD) is the major cause of death worldwide, especially in Western society. Flavonoids are a large group of polyphenolic compounds widely distributed in plants, present in a considerable amount in fruit and vegetable. Several epidemiological studies found an inverse association between flavonoids intake and mortality by CVD. The antioxidant effect of flavonoids was considered the main mechanism of action of flavonoids and other polyphenols. In recent years, the role of modulation of signaling pathways by direct interaction of flavonoids with multiple protein targets, namely kinases, has been increasingly recognized and involved in their cardiovascular protective effect. There are strong evidence, in in vitro and animal experimental models, that some flavonoids induce vasodilator effects, improve endothelial dysfunction and insulin resistance, exert platelet antiaggregant and atheroprotective effects, and reduce blood pressure. Despite interacting with multiple targets, flavonoids are surprisingly safe. This article reviews the recent evidence about cardiovascular effects that support a beneficial role of flavonoids on CVD and the potential molecular targets involved.

Achacha (Garcinia humilis) Rind Improves Cardiovascular Function in Rats with Diet-Induced Metabolic Syndrome

Garcinia humilis is a fruit known as achachairú. It is native to South American countries such as Bolivia, Peru, and Brazil, but it is also cultivated as achacha in northern Australia. The aim of this study was to determine the phytochemicals in achacha rind and pulp and to investigate these components as potential treatments for the symptoms of metabolic syndrome. Both rind and pulp contain procyanidins and citric acid rather than hydroxycitric acid. Male Wistar rats (8⁻9 weeks old) were fed with either high-carbohydrate, high-fat, or corn starch diets for 16 weeks. Intervention groups were fed with either diet supplemented with 1.5% G. humilis rind powder or 2.0% G. humilis pulp for the last 8 weeks of the protocol. Rats fed a high-carbohydrate, high-fat diet exhibited hypertension, dyslipidemia, central obesity, impaired glucose tolerance, and non-alcoholic fatty liver disease. G. humilis rind decreased systolic blood pressure, diastolic stiffness, left ventricular inflammatory cell infiltration, and collagen deposition in high-carbohydrate, high-fat diet-fed rats. However, there was no change in glucose tolerance, body weight, or body composition. Therefore, G. humilis rind, usually a food by-product, but not the edible pulp, showed potential cardioprotection with minimal metabolic changes in a rat model of diet-induced metabolic syndrome.

The effect on bioactive components and characteristics of chocolate by functionalization with raw cocoa beans

Chocolate manufacturers often develop their own original blends of cocoa beans, which, after processing, will give an unique sensory properties to their chocolates. In recent years, there has been a trend in the production of an increasing amount of low-processed or unprocessed food. Therefore, we carried out the research in which we obtained and analyzed chocolates with different blends of cocoa liquors prepared from roasted and unroasted cocoa beans of Criollo and Forastero varieties.Studies have shown that viscosity and yield value increased and hardness of chocolates lowered with the increase content of cocoa liquor from unroasted beans. Chocolates with cocoa liquor from roasted beans were characterized by the largest ability to scavenge DPPH radicals. Antioxidant activity determined by the ORAC-FL method increased with increasing polyphenol content in the chocolates. Type of the cocoa liquor used induced minor changes in the polyphenol and fatty acid composition. Asparagine was determined at the highest concentration, followed by alanine, glutamine, and serine. The concentration of acetic acid was the higher the higher the content of unroasted beans. The increased content of cocoa liquor from unroasted beans caused the color of the chocolate to brighten, more red and yellow. All tested chocolates were characterized by good organoleptic properties and microbial stability.

Potential mechanisms underlying cardiovascular protection by polyphenols: Role of the endothelium

Epidemiological studies have indicated that regular intake of polyphenol-rich diets such as red wine and tea, are associated with a reduced risk of cardiovascular diseases. The beneficial effect of polyphenol-rich products has been attributable, at least in part, to their direct action on the endothelial function. Indeed, polyphenols from tea, grapes, cacao, berries, and plants have been shown to activate endothelial cells to increase the formation of potent vasoprotective factors including nitric oxide (NO) and to delay endothelial ageing. Moreover, intake of such polyphenol-rich products has been associated with the prevention and/or the improvement of an established endothelial dysfunction in several experimental models of cardiovascular diseases and in Humans with cardiovascular diseases. This review will discuss both experimental and clinical evidences indicating that polyphenols are able to promote endothelial and vascular health, as well as the underlying mechanisms.

Biological activities of Agave by-products and their possible applications in food and pharmaceuticals

Agave leaves are considered a by-product of alcoholic beverage production (tequila, mezcal and bacanora) because they are discarded during the production process, despite accounting for approximately 50% of the total plant weight. These by-products constitute a potential source of Agave extracts rich in bioactive compounds, such as saponins, phenolic compounds and terpenes, and possess different biological effects, as demonstrated by in vitro and in vivo tests (e.g. antimicrobial, antifungal, antioxidant, anti-inflammatory, antihypertensive, immunomodulatory, antiparasitic and anticancer activity). Despite their positive results in biological assays, Agave extracts have not been widely evaluated in food systems and pharmaceutical areas, and these fields represent a potential route to improve the usage of Agave plants as food additives and agents for treating medical diseases. © 2017 Society of Chemical Industry.

Anti-Hypertensive Effects of Acacia Polyphenol in Spontaneously Hypertensive Rats

We have previously demonstrated that acacia polyphenol (AP) exerts strong anti-obesity, anti-diabetic, and anti-atopic dermatitis effects. In the present study, we investigated the anti-hypertensive effects of AP. Spontaneously hypertensive rats (SHR) with hypertension and control Wistar Kyoto rats (WKY) were used. WKY and SHR were fed AP-containing food or AP-free food (control group) ad libitum for 4 weeks, and their blood pressures were measured. After AP administration, both systolic and diastolic blood pressures were significantly lower in the SHR group than in the control group. There were no differences in the systolic or diastolic blood pressure of WKY between the AP group and the control group. Angiotensin-converting enzyme (ACE) activity, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression, and superoxide dismutase (SOD) activity in SHR kidneys were not altered by AP administration. Blood SOD activity in SHR was significantly higher in the AP group than in the control group. AP exerts anti-hypertensive effects on hypertension but has almost no effect on normal blood pressure. The anti-hypertensive effects of AP may be related to the anti-oxidative effects of increased blood SOD activity.

Cocoa, Blood Pressure, and Vascular Function

Cardiovascular disease (CVD) represents the most common cause of death worldwide. The consumption of natural polyphenol-rich foods, and cocoa in particular, has been related to a reduced risk of CVD, including coronary heart disease and stroke. Intervention studies strongly suggest that cocoa exerts a beneficial impact on cardiovascular health, through the reduction of blood pressure (BP), improvement of vascular function, modulation of lipid and glucose metabolism, and reduction of platelet aggregation. These potentially beneficial effects have been shown in healthy subjects as well as in patients with risk factors (arterial hypertension, diabetes, and smoking) or established CVD (coronary heart disease or heart failure). Several potential mechanisms are supposed to be responsible for the positive effect of cocoa; among them activation of nitric oxide (NO) synthase, increased bioavailability of NO as well as antioxidant, and anti-inflammatory properties. It is the aim of this review to summarize the findings of cocoa and chocolate on BP and vascular function.

Flavanol plasma bioavailability is affected by metabolic syndrome in rats

Flavanols, which exert several health benefits, are metabolized after ingestion. Factors such as the host physiological condition could affect the metabolism and bioavailability of flavanols, influencing their bioactivities. This study aimed to qualitatively evaluate whether a pathological state influenced flavanol plasma bioavailability. Standard and cafeteria (CAF) diet fed rats, a robust model of metabolic syndrome (MeS), were administered 1000mg/kg of flavanol enriched grape seed polyphenol extract (GSPE). Flavanols and their metabolites were quantified by HPLC-MS/MS in plasma before and at 2, 4, 7, 24, and 48h after GSPE ingestion. Results showed that in CAF administered rats the maximum time of plasma flavanol concentration was delayed and these animals presented higher levels of plasma phase-II metabolites as well as altered microbial metabolites. In conclusion, this study demonstrated that MeS pathological state modified flavanol bioavailability, supporting the hypothesis that flavanol metabolism, and therefore flavanol functionality, depend on the organism's state of health.

The Cardiovascular Effects of Cocoa Polyphenols-An Overview

Cocoa is a rich source of high-quality antioxidant polyphenols. They comprise mainly catechins (29%-38% of total polyphenols), anthocyanins (4% of total polyphenols) and proanthocyanidins (58%-65% of total polyphenols). A growing body of experimental and epidemiological evidence highlights that the intake of cocoa polyphenols may reduce the risk of cardiovascular events. Beyond antioxidant properties, cocoa polyphenols exert blood pressure lowering activity, antiplatelet, anti-inflammatory, metabolic and anti-atherosclerotic effects, and also improve endothelial function. This paper reviews the role of cocoa polyphenols in cardiovascular protection, with a special focus on mechanisms of action, clinical relevance and correlation between antioxidant activity and cardiovascular health.

Hematological changes and nitric oxide levels accompanying high-dose artemether-lumefantrine administration in male guinea pigs: Effect of unsweetened natural cocoa powder

BACKGROUND

Unsweetened natural cocoa powder (UNCP), prepared after removal of the cocoa butter, is a common beverage in Ghana. It possesses antimalarial prophylactic property and has a beneficial effect on blood components.

AIM

The aim of this study was to determine whether regular dietary supplement of UNCP mitigates high-dose (HD) artemether-lumefantrine (A-L)-induced hematological disorders and to determine the effect on nitric oxide (NO) levels.

MATERIALS AND METHODS

Adult male guinea pigs (300 g - 350 g) were randomly divided into 5 groups of 6 guinea pigs each. Among the 5 groups, 3 groups were treated with UNCP (300, 900, and 1500 mg/kg body weight) for 14 days. A-L (75 mg/kg) was administered from the 12th to 14th day. One of the remaining 2 groups received distilled water only, i.e., vehicle control group (VCG) while the other received 75 mg/kg A-L only, i.e., negative control group (NCG). Blood samples from all groups were obtained by cardiac puncture (day 15) followed by hematological and NO analysis.

RESULTS

A-L reduced white blood cells (WBC) by 31.87%, lymphocyte count by 45.99%, hemoglobin by 11.72%, hematocrit by 18.56%, and platelet count by 33.08% in the NCG. Administration of various doses of UNCP increased WBC and lymphocyte count (P > 0.05) compared to the NCG. UNCP and A-L combination caused an increase in NO levels when compared to the VCG.

CONCLUSION

Regular consumption of UNCP by guinea pigs increases plasma NO and restores some hematological disorders induced by a 3-day HD A-L administration.

Targeting Nitric Oxide with Natural Derived Compounds as a Therapeutic Strategy in Vascular Diseases

Within the family of endogenous gasotransmitters, nitric oxide (NO) is the smallest gaseous intercellular messenger involved in the modulation of several processes, such as blood flow and platelet aggregation control, essential to maintain vascular homeostasis. NO is produced by nitric oxide synthases (NOS) and its effects are mediated by cGMP-dependent or cGMP-independent mechanisms. Growing evidence suggests a crosstalk between the NO signaling and the occurrence of oxidative stress in the onset and progression of vascular diseases, such as hypertension, heart failure, ischemia, and stroke. For these reasons, NO is considered as an emerging molecular target for developing therapeutic strategies for cardio- and cerebrovascular pathologies. Several natural derived compounds, such as polyphenols, are now proposed as modulators of NO-mediated pathways. The aim of this review is to highlight the experimental evidence on the involvement of nitric oxide in vascular homeostasis focusing on the therapeutic potential of targeting NO with some natural compounds in patients with vascular diseases.

Long-term antihypertensive effect of a soluble cocoa fiber product in spontaneously hypertensive rats

Background and Methods

This study evaluates the antihypertensive effect of long-term intake of a soluble cocoa fiber product (SCFP). Different doses of SCFP were evaluated (200, 400, and 800 mg/kg/day) and a dose of 800 mg/kg/day of beta-glucan 0.75 (BETA-G) was used as a standard fiber. Water, a neutral vehicle, was used as negative control, and 50 mg/kg/day captopril was used as positive control. Systolic blood pressure (SBP) was measured weekly by the tail cuff method. Body weight, food, and liquid intake were also registered weekly in the rats from 10 to 24 weeks of life. Glucose, total cholesterol, and triglyceride levels; redox status; and the angiotensin-converting enzyme activity were also studied in the plasma samples of these animals.

Results

Throughout the 10 weeks of treatment, captopril and SCFP (400 mg/kg/day) demonstrated blood pressure lowering effects in the spontaneously hypertensive rats (p<0.05; n=8). Paradoxically, neither the highest dose (800 mg/kg/day) of SCFP decreased SBP nor 800 mg/kg/day BETA-G (p>0.05; n=8). When the corresponding antihypertensive treatment, was disrupted the SBP values of the 400 mg/kg/day SCFP treated animals returned to control values (p>0.05; n=8). In addition, the SCFP significantly decreased (p<0.05; n=4) the glucose, cholesterol, and triglyceride levels and also the liver and plasma malondaldehyde levels. Moreover, the SCFP slightly increased the reduced glutathione levels in the liver.

Conclusion

The SCFP could be used to control the blood pressure of hypertensive subjects for a long period of time and could improve metabolic complications associated to cardiovascular diseases.

The content of polyphenolic compounds in cocoa beans (Theobroma cacao L.), depending on variety, growing region, and processing operations: a review

Polyphenols form the largest group of compounds among natural antioxidants, which largely affect the overall antioxidant and anti-free radical activity of cocoa beans. The qualitative and quantitative composition of individual fractions of polyphenolic compounds, even within one species, is very diverse and depends on many factors, mainly on the area of cocoa trees cultivation, bean maturity, climatic conditions during growth, and the harvest season and storage time after harvest. Thermal processing of cocoa beans and cocoa derivative products at relatively high temperatures may in addition to favorable physicochemical, microbiological, and organoleptic changes result in a decrease of polyphenols concentration. Technological processing of cocoa beans negatively affects the content of polyphenolic compounds.

Flavor Chemistry of Cocoa and Cocoa Products-An Overview

Cocoa originates from beans of the cocoa tree (Theobroma cacao L.) and it is an important commodity in the world and the main ingredient in chocolate manufacture. Its value and quality are related to unique and complex flavors. Bulk cocoas (Forastero type) exhibit strong basic cocoa notes, whereas fine varieties (Criollo, Nacional) show aromatic, floral, or smoother flavor characteristics. About 600 various compounds (alcohols, carboxylic acids, aldehydes, ketones, esters, and pyrazines) have been identified as odor-active components. The specific cocoa aroma arises from complex biochemical and chemical reactions during the postharvest processing of raw beans, and from many influences of the cocoa genotype, chemical make-up of raw seeds, environmental conditions, farming practices, processing, and manufacturing stages. There has been much research on cocoa flavor components. However, the relationships between all chemical components that are likely to play a role in cocoa flavor, their sensory properties, and the sources and mechanisms of flavor formation are not fully understood. This paper provides an overview on cocoa flavor from a compositional and a sensory perspective. The nonvolatile and volatile chemical components of cocoa and chocolate flavor, and their sensory properties correlated to the main influences involved in flavor formation, are reviewed.

Cocoa, blood pressure, and cardiovascular health

High blood pressure is an important risk factor for cardiovascular disease and cardiovascular events worldwide. Clinical and epidemiological studies suggest that cocoa-rich products reduce the risk of cardiovascular disease. According to this, cocoa has a high content in polyphenols, especially flavanols. Flavanols have been described to exert favorable effects on endothelium-derived vasodilation via the stimulation of nitric oxide-synthase, the increased availability of l-arginine, and the decreased degradation of NO. Cocoa may also have a beneficial effect by protecting against oxidative stress alterations and via decreased platelet aggregation, decreased lipid oxidation, and insulin resistance. These effects are associated with a decrease of blood pressure and a favorable trend toward a reduction in cardiovascular events and strokes. Previous meta-analyses have shown that cocoa-rich foods may reduce blood pressure. Long-term trials investigating the effect of cocoa products are needed to determine whether or not blood pressure is reduced on a chronic basis by daily ingestion of cocoa. Furthermore, long-term trials investigating the effect of cocoa on clinical outcomes are also needed to assess whether cocoa has an effect on cardiovascular events. A 3 mmHg systolic blood pressure reduction has been estimated to decrease the risk of cardiovascular and all-cause mortality. This paper summarizes new findings concerning cocoa effects on blood pressure and cardiovascular health, focusing on putative mechanisms of action and "nutraceutical " viewpoints.

Lack of tissue accumulation of grape seed flavanols after daily long-term administration in healthy and cafeteria-diet obese rats

After ingestion flavanols are metabolized by phase-II enzymes and the microbiota and are distributed throughout the body depending on several factors. Herein we aim to evaluate whether flavanols are tissue-accumulated after the long-term administration of a grape seed polyphenol extract (GSPE) in rats and to study if compounds present in tissues differ in a cafeteria-diet obesity state. For that, plasma, liver, mesenteric white adipose tissue (MWAT), brain, and aorta flavanol metabolites from standard chow-diet-fed (ST) and cafeteria-diet-fed (CAF) rats were analyzed by high-performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) 21 h after the last 12-week-daily GSPE (100 mg/kg) dosage. Results showed that long-term GSPE intake did not trigger a flavanol tissue accumulation, indicating a clearance of products at each daily dosage. Therefore, results suggest that polyphenol benefits in a disease state would be due to a daily pulsatile effect. Moreover, obesity induced by diet also influences the metabolism and bioavailability of flavanols in rats.

Modulation of nitric oxide by flavonoids

One of the main mechanisms by which dietary flavonoids are thought to influence cardiovascular disease is via protection of the bioactivity of the endothelium-derived nitric oxide (NO). Additionally, flavonoids may also interfere with the signalling cascades of inflammation and prevent overproduction of NO and its deleterious consequences in shock and ischemia-reperfusion injury. In the present paper we review the evidence of the effects of flavonoids on NO. Flavonoids exert complex actions on the synthesis and bioavailability of NO which may result both in enhanced or decreased NO levels: (1) in cell free systems, several flavonoids may scavenge NO via its pro-oxidant properties by increasing superoxide. However, under conditions of oxidative stress, flavonoids may also protect NO from superoxide-driven inactivation. (2) In intact healthy tissues, some flavonoids increase eNOS activity in endothelial cells. Paradoxically this effect involves a pro-oxidant effect which results in Ca(2+)-dependent activation of eNOS. As inhibitors of PI3K, flavonoids may potentially inhibit the PI3K/Akt-dependent activation of eNOS. (3) Under conditions of inflammation and oxidative stress, flavonoids may prevent the inflammatory signalling cascades via inhibition of NFκB and thereby downregulate iNOS. On the other hand, they also prevent the overexpression of ROS generating enzymes, reducing superoxide and peroxynitrite levels, and hence preventing superoxide-induced NO inactivation and eNOS uncoupling. Therefore, the final effect of flavonoids on NO levels will depend on the flavonoid structure and the concentrations used, on the cell type under study and particularly on the presence of inflammatory/oxidative conditions.

The blood pressure effect and related plasma levels of flavan-3-ols in spontaneously hypertensive rats

We studied the short-term antihypertensive effect of flavan-3-ols (−)-epicatechin, (+)-catechin and (−)-catechin, in spontaneously hypertensive rats (SHR).

Dietary flavonoids added to pharmacological antihypertensive therapy are effective in improving blood pressure

Epidemiological studies have suggested that the daily intake of flavonoids is associated with a decreased risk of developing cardiovascular disease. Our purpose was to evaluate the effect of the addition of dietary flavonoids (DF) to antihypertensive treatment (AHT), based on telmisartan (Tms) or captopril (Cpr), on blood pressure (BP), body mass index (BMI), waist/hip ratio, leptin, lipid profile and inflammation in hypertensive young patients. An open-label, randomized, controlled trial was performed among 79 patients aged 20-55 years with grade I or grade II systemic arterial hypertension. The subjects were assigned to one of four groups for AHT plus DF during 6 months: Cpr (n = 14), Cpr + DF (n = 19), Tms (n = 25) and Tms + DF (n = 21). DF consisted of dark chocolate, dehydrated red apple and green tea in an infusion to obtain a daily dose of 425.8 ± 13.9 mg epicatechin equivalents. The BP and anthropometric parameters were measured every 2 weeks. Lipid profile, leptin and hsCRP were determined by standard methods. The combination AHT-DF produced an additional and significant reduction in (i) SBP/DBP of -5/-4 mmHg, being -7/-5 for Cpr + DF and -4/-3 for Tms + DF; (ii) triglyceride levels (-30.6%) versus AHT alone (-9.6%); and (iii) leptin: Cpr + DF versus Tms + DF (p < 0.005). Finally, C-reactive protein plasma levels were reduced significantly in all groups independently of the applied treatment. We conclude that the addition of flavonoids to pharmacological antihypertensive therapy shows additional benefits on BP, lipid profile, leptin, obesity and inflammation.

Realistic intake of a flavanol-rich soluble cocoa product increases HDL-cholesterol without inducing anthropometric changes in healthy and moderately hypercholesterolemic subjects

To assess whether antioxidant, anti-inflammatory and other cardio-protective effects attributed to cocoa are achieved when regularly consuming moderate amounts of a flavanol-rich soluble cocoa product, a non-randomized, controlled, crossover, free-living study was carried out in healthy (n = 24; 25.9 ± 5.6 years) and moderately hypercholesterolemic (200-240 mg dL(-1); n = 20; 30.0 ± 10.3 years) volunteers. Participants consumed two servings per day (7.5 g per serving) of a soluble cocoa product (providing 45.3 mg flavanols per day) in milk, which was compared with consuming only milk during a 4 week period. The effects on systolic and diastolic blood pressure and heart rate were determined, as well as on serum lipid and lipoprotein profiles, interleukins (IL)-1β, IL-6, IL-8, IL-10, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), vascular (VCAM-1) and intercellular cell adhesion molecules (ICAM-1), serum malondialdehyde (MDA), carbonyl groups (CG), ferric reducing/antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and free radical scavenging capacity (ABTS). During the study, the volunteers' diets and physical activity were also evaluated, as well as any changes in weight, skin folds, circumferences and related anthropometric parameters. Cocoa and certain polyphenol-rich fruits and vegetables and their derivatives were restricted. After consuming the cocoa product positive effects were observed such as an increase in serum HDL-C (p < 0.001) and dietary fiber intake (p = 0.050), whereas IL-10 decreased (p = 0.022). Other cardiovascular-related biomarkers and anthropometric parameters were unaffected. We have therefore concluded that regular consumption of this cocoa product in a Spanish-Mediterranean diet may protect against cardiovascular disease in healthy and hypercholesterolemic subjects without producing any weight gain or other anthropometric changes.

Synthesis and anti-hypertensive effects of the twin drug of nicotinic acid and quercetin tetramethyl ether

A novel twin drug consisting of nicotinic acid (VB3) and quercetin tetramethyl ether (QTME) has been synthesized as an antihypertensive in a total yield of 79.2% through methylation, hydrolysis, acylation and esterification starting from rutin. The structures of synthesized compounds were elucidated by 1H-NMR, 13C-NMR and elemental analysis. The anti-hypertensive effects of an oral daily dose (15 mg/kg) of the synthesized compounds in spontaneously hypertensive (SHR) rats and normotensive Wistar Kyoto (WKY) rats were analysed. The data demonstrate that the twin drug VB3-QTME both reduces the elevated blood pressure and prolongs the action time in SHR rats without effect on WKY rats. However, definitive evidence of a precise mechanism of action by which VB3-QTME might decrease blood pressure remains elusive. Based on the results, the therapeutic potential of this twin drug is discussed.

Long-Term Effect of an Aqueous Fraxinus excelsior L. Seed Extract in Spontaneously Hypertensive Rats

The effect of long-term intake of different doses (20, 40, and 60 mg/kg/day) of a Fraxinus excelsior L. seed extract (FESE) on spontaneously hypertensive rats (SHR) was evaluated. Water was used as control and captopril (50 mg/kg/day) was used as positive control. Systolic blood pressure, body weight, and food and liquid intake were registered weekly in SHR. The antioxidant and vascular relaxing properties of FESE were also studied in these animals. The development of hypertension was attenuated in the groups treated with captopril or FESE. The antihypertensive effect was more accentuated in the captopril group than in the FESE groups, and it was paradoxically more accentuated in the groups treated with 20 mg/kg/day or 40 mg/kg/day of FESE than in the group treated with the highest dose of this extract. Body weight gain and food intake increased in the FESE groups. After removing the corresponding antihypertensive treatment, the arterial blood pressure and the body weight of the FESE treated animals returned to control values. In addition, FESE increased plasma antioxidant capacity and decreased plasma and liver malondialdehyde levels. Moreover, acetylcholine relaxation improved in the aorta rings from the FESE treated rats.

Inhibitory effect of catechin-related compounds on renin activity

Renin is a crucial enzyme in the renin-angiotensin system, and the inhibition of its activity is considered as a useful approach to the treatment of hypertension. The inhibitory effect of catechin-related compounds on renin was investigated in this work. It was found that epigallocatechin gallate (EGCg) possessed the strongest activity with an IC₅₀ value of 44.53 μM and acted in an uncompetitive manner. Gallated catechins exerted higher inhibition than the ungallated forms, and gallic acid exhibited an inhibitory potency close to that of epicatechin gallate (ECg). Results indicated that the galloyl moiety and ortho-trihydroxy phenyl structures might be favorable for the renin-inhibitory activity of these compounds.

Synthesis and β-adrenergic blocking activity of oxime ether hybrids derived from a natural isochroman-4-one

AIM

In a search for new cardiovascular drug candidates, a series of novel oxime ethers derived from a natural isochroman-4-one were synthesized.

METHOD

Compounds 3 and 6, derived from the natural antihypertensive compound 7, 8-dihydroxy-3-methyl-isochroman-4-one (XJP), were designed and synthesized. Subsequently, a series of novel isochroman-4-one oxime ether hybrids were prepared by hybridizing various N-substituted isopropanolamine functionalities to isochroman-4-one oxime. Furthermore, β1-adrenergic blocking activities of the synthesized compounds were assayed using the isolated rat left atria.

RESULTS

Twenty target compounds were obtained, and the preliminary structure-activity relationships were deduced. The most promising compound Ic exhibited β1-adrenoceptor blocking activity (inhibition: 52.2%) at 10(-7) mol·L(-1), which was superior to that of propranolol (inhibition: 49.7%).

CONCLUSION

The results suggested that natural product XJP/isopropanolamine moiety hybrids may provide a promising approach for the discovery of novel cardiovascular drug candidates.

Tea polyphenols as novel and potent inhibitory substances against renin activity

Renin inhibitory activities of three tea products were investigated for the first time in this work. Water extracts from fermented oolong and black tea showed strong renin inhibitory activities. By the means of ultrafiltration, gradient high performance liquid chromatography and spectroscopic analysis, four active compounds were separated from aqueous black tea extract and identified as theasinensin B, theasinensin C, strictinin, and a hexose sulfate with a galloyl moiety, which had IC50 values of 19.33, 40.21, 311.09, and 50.16 μM against renin activity, respectively. Further detection indicated that the potent inhibitor theasinensin B was present only in black tea, and that monomeric catechins did not contribute significantly to the renin inhibitory activities of tea products. These results revealed novel and potent tea-derived renin inhibitors and suggested another potential pathway for tea consumption to control hypertension.

Cocoa flavonoid-enriched diet modulates systemic and intestinal immunoglobulin synthesis in adult Lewis rats

Previous studies have reported that a diet containing 10% cocoa, a rich source of flavonoids, has immunomodulatory effects on rats and, among others effects, is able to attenuate the immunoglobulin (Ig) synthesis in both systemic and intestinal compartments. The purpose of the present study was focused on investigating whether these effects were attributed exclusively to the flavonoid content or to other compounds present in cocoa. To this end, eight-week-old Lewis rats were fed, for two weeks, either a standard diet or three isoenergetic diets containing increasing proportions of cocoa flavonoids from different sources: one with 0.2% polyphenols from conventional defatted cocoa, and two others with 0.4% and 0.8% polyphenols, respectively, from non-fermented cocoa. Diet intake and body weight were monitored and fecal samples were obtained throughout the study to determine fecal pH, IgA, bacteria proportions, and IgA-coated bacteria. Moreover, IgG and IgM concentrations in serum samples collected during the study were quantified. At the end of the dietary intervention no clear changes of serum IgG or IgM concentrations were quantified, showing few effects of cocoa polyphenol diets at the systemic level. However, in the intestine, all cocoa polyphenol-enriched diets attenuated the age-related increase of both fecal IgA and IgA-coated bacteria, as well as the proportion of bacteria in feces. As these effects were not dependent on the dose of polyphenol present in the diets, other compounds and/or the precise polyphenol composition present in cocoa raw material used for the diets could be key factors in this effect.

(-)-Epicatechin reduces blood pressure and improves vasorelaxation in spontaneously hypertensive rats by NO-mediated mechanism

Studies in humans have found consumption of certain flavanoid-containing foods to be associated with improvement in endothelial function and with reduction of blood pressure (BP). (-)-Epicatechin is a compound representative of the flavanols (a subfamily of flavonoids), abundant in cocoa seeds, which is preserved during the industrialization process to chocolate. The antihypertensive effect of dietary (-)-epicatechin was investigated on spontaneously hypertensive rats (SHRs). Consumption of (-)-epicatechin-supplemented diet (3 g (-)-epicatechin/kg diet) decreased BP in SHR by 27 and 23 mm Hg on days 2 and 6, respectively. On day 6, a 173% increase of nitric oxide synthase (NOS) activity was observed in the aorta of EPI-SHR as compared to nonsupplemented SHR (P < 0.05). Responses to acetylcholine (ACh) were then examined in femoral arteries in the absence and the presence of L-NAME, a nonselective NOS inhibitor, to assess the ACh-mediated relaxation ascribed to NO-dependent and -independent mechanisms. Acetylcholine-induced endothelium-dependent relaxation in the femoral artery was significantly higher in EPI-SHR than in SHR, with a predominance of the NO-dependent component of this relaxation. The endothelium-independent relaxation, assayed by using the NO donor sodium nitroprusside, resulted in nonsignificant difference in the three experimental groups, demonstrating an unaffected function of vascular smooth muscle cells. These results give further support to the concept that (-)-epicatechin can modulate BP in hypertension by increasing NO levels in the vasculature.