ORGANIC COCOA RESEARCH

 

Cocoa has more phenolic phytochemicals and a higher antioxidant capacity than teas and red wine.

 

J Agric Food Chem 2003 Dec 3;51(25):7292-5    (ISSN: 0021-8561)

 

Lee KW; Kim YJ; Lee HJ; Lee CY
Department of Food Science and Technology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, South Korea.

Black tea, green tea, red wine, and cocoa are high in phenolic phytochemicals, among which theaflavin, epigallocatechin gallate, resveratrol, and procyanidin, respectively, have been extensively investigated due to their possible role as chemopreventive agents based on their antioxidant capacities. The present study compared the phenolic and flavonoid contents and total antioxidant capacities of cocoa, black tea, green tea, and red wine. Cocoa contained much higher levels of total phenolics (611 mg of gallic acid equivalents, GAE) and flavonoids (564 mg of epicatechin equivalents, ECE) per serving than black tea (124 mg of GAE and 34 mg of ECE, respectively), green tea (165 mg of GAE and 47 mg of ECE), and red wine (340 mg of GAE and 163 mg of ECE). Total antioxidant activities were measured using the 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays and are expressed as vitamin C equivalent antioxidant capacities (VCEACs). Cocoa exhibited the highest antioxidant activity among the samples in ABTS and DPPH assays, with VCEACs of 1128 and 836 mg/serving, respectively. The relative total antioxidant capacities of the samples in both assays were as follows in decreasing order: cocoa > red wine > green tea > black tea. The total antioxidant capacities from ABTS and DPPH assays were highly correlated with phenolic content (r2 = 0.981 and 0.967, respectively) and flavonoid content (r2 = 0.949 and 0.915). These results suggest that cocoa is more beneficial to health than teas and red wine in terms of its higher antioxidant capacity.

 

 

 

 

 

Ingested cocoa can prevent high-fat diet-induced obesity by regulating the expression of genes for fatty acid metabolism [In Process Citation]

 

Nutrition 2005 May;21(5):594-601     (ISSN: 0899-9007)

 

Matsui N; Ito R; Nishimura E; Yoshikawa M; Kato M; Kamei M; Shibata H; Matsumoto I; Abe K; Hashizume S
Research Institute, Morinaga & Co., Ltd., Kanagawa, Japan.

OBJECTIVE: We previously found that ingested cocoa decreased visceral adipose tissue weight in rat. To elucidate the molecular mechanisms of that effect, we carried out experiments aimed at analyzing biochemical parameters and gene expression profiles. METHODS: Rats were fed either of two high-fat diets, differing only in supplementation with real or mimetic cocoa. On day 21, body weights, mesenteric white adipose tissue weights, and concentrations of serum triacylglycerol were measured. To investigate the molecular mechanisms underlying the effects of cocoa on lipid metabolism and triacylglycerol accumulation, we examined gene expression profiles in liver and mesenteric white adipose tissues using the GeneChip microarray system. RESULTS: Final body weights and mesenteric white adipose tissue weights were significantly lower in rats fed the real cocoa diet than in those fed the mimetic cocoa diet (P < 0.05), and serum triacylglycerol concentrations tended to be lower in rats fed the real cocoa diet (P = 0.072). DNA microarray analysis showed that cocoa ingestion suppressed the expression of genes for enzymes involved in fatty acid synthesis in liver and white adipose tissues. In white adipose tissue, cocoa ingestion also decreased the expression of genes for fatty acid transport-relating molecules, whereas it upregulated the expression of genes for uncoupling protein-2 as a thermogenesis factor. CONCLUSIONS: Ingested cocoa can prevent high-fat diet-induced obesity by modulating lipid metabolism, especially by decreasing fatty acid synthesis and transport systems, and enhancement of part of the thermogenesis mechanism in liver and white adipose tissue.

 

 

 

 

 

Cocoa polyphenols and inflammatory mediators.

 

Am J Clin Nutr 2005 Jan;81(1 Suppl):304S-312S    (ISSN: 0002-9165)

 

Sies H; Schewe T; Heiss C; Kelm M
Institute for Biochemistry and Molecular Biology I and the Department of Medicine, Division of Cardiology, Pulmonary Diseases, and Angiology, Heinrich Heine University Dusseldorf, Dusseldorf, Germany. sies@uni-duesseldorf.de.

Cocoa products are sources of flavan-3-ols, which have attracted interest regarding cardiovascular health. This review provides a survey of our research on the effects of cocoa polyphenols on leukotriene and nitric oxide (NO) metabolism and on myeloperoxidase-induced modification of LDL. Because intake of flavonoid-rich chocolate by human subjects was reported to decrease the plasma concentrations of proinflammatory cysteinyl leukotrienes, we assessed whether cocoa polyphenols inhibited human 5-lipoxygenase, the key enzyme of leukotriene synthesis. (-)-Epicatechin and other cocoa flavan-3-ols proved to be inhibitory at the enzyme level. This action may confer antileukotriene action in vivo. In a double-blind crossover study, 20 individuals at risk for cardiovascular diseases received cocoa beverages with high or low contents of flavan-3-ols. NO-dependent, flow-mediated dilation of the brachial artery and concentrations of nitroso compounds in plasma were measured, and it was shown that ingestion of the high-flavanol coca drink but not the low-flavanol cocoa drink significantly increased plasma concentrations of nitroso compounds and flow-mediated dilation of the brachial artery. Therefore, ingested flavonoids may reverse endothelial dysfunction through enhancement of NO bioactivity. Oxidative modification of LDL appears to be crucial for atherogenesis, and one of the mediators is the proinflammatory proatherogenic enzyme myeloperoxidase. Micromolar concentrations of (-)-epicatechin or other flavonoids were found to suppress lipid peroxidation in LDL induced by myeloperoxidase in the presence of physiologically relevant concentrations of nitrite, an NO metabolite. Adverse effects of NO metabolites, such as nitrite and peroxynitrite, were thus attenuated.

 

 

 

 

 

Cocoa and chocolate flavonoids: implications for cardiovascular health.

 

J Am Diet Assoc 2003 Feb;103(2):215-23    (ISSN: 0002-8223)

 

Steinberg FM; Bearden MM; Keen CL
Didactic Program in Dietetics, Department of Nutrition, University of California, Davis, CA, USA. fmsteinberg@ucdavis.edu.

This paper offers a review of current scientific research regarding the potential cardiovascular health benefits of flavonoids found in cocoa and chocolate. Recent reports indicate that the main flavonoids found in cocoa, flavan-3-ols and their oligomeric derivatives, procyanidins, have a variety of beneficial actions, including antioxidant protection and modulation of vascular homeostasis. These findings are supported by similar research on other flavonoid-rich foods. Other constituents in cocoa and chocolate that may also influence cardiovascular health are briefly reviewed. The lipid content of chocolate is relatively high; however, one third of the lipid in cocoa butter is composed of the fat stearic acid, which exerts a neutral cholesterolemic response in humans. Cocoa and chocolate contribute to trace mineral intake, which is necessary for optimum functioning of all biologic systems and for vascular tone. Thus, multiple components in chocolate, particularly flavonoids, can contribute to the complex interplay of nutrition and health. Applications of this knowledge include recommendations by health professionals to encourage individuals to consume a wide range of phytochemical-rich foods, which can include dark chocolate in moderate amounts.

 

 

 

 

 

Suppressive Effect of Cocoa Powder on Atherosclerosis in Kurosawa and Kusanagi-hypercholesterolemic Rabbits [In Process Citation]

 

J Atheroscler Thromb 2005;12(1):20-8     (ISSN: 1340-3478)

 

Kurosawa T; Itoh F; Nozaki A; Nakano Y; Katsuda S; Osakabe N; Tsubone H; Kondo K; Itakura H
Toxicology Laboratory, Pharmaceutical Development Department, Meiji Seika Kaisha, Ltd., Kanagawa, Japan.

We investigated the suppressive effect of cocoa powder (cacao polyphenol content: 7.8%) on atherosclerosis in a spontaneous familial hypercholesterolemic model, Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits. Six-month dietary administration of cocoa powder had no effects on body weight, hematology or blood chemistry parameters or a lipid profile in KHC rabbits. Antioxidative activity of low-density lipoprotein (LDL) was observed in the 2nd month and 3rd month of administration. Thiobarbituric acid reactive substances (TBARS), the marker of lipid peroxidation, in plasma were decreased in the cocoa powder treated group from the 2nd month of administration during the study period compared to that in the control group. The area of atherosclerotic lesions in th aorta was significantly smaller in the cocoa powder group (30.87%) than in the control (52.39%). Tissue cholesterol content also tended to decrease. Distensibility of the aortic wall was improved significantly in the cocoa powder treated group due to decreases in fatty streaks and intimal thickening compared to that in the control group. These results suggest that cocoa powder has suppressive effect on development of atherosclerotic lesions. We consider that antioxidative activity of polyphenols rich in cocoa powder may be a key factor for the anti-atherosclerotic effect.

 

 

 

 

 

Membrane effects of cocoa procyanidins in liposomes and Jurkat T cells.

 

Biol Res 2004;37(2):293-300    (ISSN: 0716-9760)

 

Verstraeten SV; Oteiza PI; Fraga CG
IQUIFIB-Department of Biological Chemistry, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.

We investigated the effects of the interaction between flavanols and related procyanidins (dimer to hexamer) with both cell and synthetic membranes, on bilayer fluidity and susceptibility to oxidation. Cocoa derived dimers (0.05 to 1 microg/ml) protected Jurkat T cells from AMVN-mediated oxidation and increased plasma membrane fluidity. These effects occurred in a concentration- and chain length-dependent manner. In liposomes, procyanidins prevented the Fe2+ -induced permeabilization of the membrane. Together, these results support the hypothesis that procyanidins could interact with the polar headgroup of lipids, increasing membrane fluidity and also, preventing the access of molecules that could affect membrane integrity.

 

 

 

 

 

The effect of a catechin-rich extract of Cocos nucifera on lymphocytes proliferation.

 

Phytother Res 2003 Nov;17(9):1054-8    (ISSN: 0951-418X)

 

Kirszberg C; Esquenazi D; Alviano CS; Rumjanek VM
Laboratorio de Imunologia Tumoral, Departamento de Bioquimica Medica,
Brazil.

Catechins are polyphenols with antioxidant activity. The fruit Cocos nucifera (Palmae) has a fi ber husk rich in catechins and the local population of northeast Brazil uses it as a medicine against various diseases. An anti-bacterial and anti-viral activity has been already observed using this substance. Plant extracts, from other sources, rich in catechins are inhibitory to tumour cells, suppressing their proliferation. The aim of the present work was to verify if catechins isolated from Cocos nucifera were capable of inhibiting cell proliferation. An extract obtained from Cocos nucifera was purified through adsorption chromatography using the resin XAD-2. The purified material was used in cultures of an erythroleukaemia cell line (K562) and on normal human peripheral blood lymphocytes. Cell viability was assessed using MTT. Cellular proliferation was measured by [(3)H]-thymidine incorporation and cell cycle analysis in a fl ow cytometer. A dose-dependent inhibitory effect was observed on tumour cells and on lymphocytes activated by phytohemaglutinin (PHA) or phorbol ester. For PHA this effect was irreversible being already established on the fi rst four hours of culture. [Copyright 2003 John Wiley & Sons, Ltd.].