Epicatechin from green tea health benefit
The pharmacological actions of green tea are mainly attributed to polyphenols that includes epigallocatechin-3-gallate (EGCG), epicatechin, epicatechin-3-gallate, epigallocatechin. Green tea and its components effectively reduce cellular damage arising due to oxidative stress. Green tea is supposed to enhance humoral and cell-mediated immunity, decreasing the risk of certain cancers, and may have certain advantage in treating inflammatory disorders.
Biobased Epicatechin Conjugates Protect Erythrocytes
and Nontumoral Cell Lines from H(2)O(2)-Induced Oxidative Stress.
J Agric Food Chem. 2009. Ugartondo V, Mitjans M, Torres JL, Vinardell MP.Departament de Fisiologia, Facultat de Farmacia, Universitat de Barcelona, Avinguda Joan XXIII s/n, 08028 Barcelona, Spain.
This paper reports the study of the protective action of epicatechin and epicatechin derivatives, obtained by depolymerizing polymeric flavanols in the presence of cysteine or cysteamine, on red blood cells (RBC) and nontumoral cell lines challenged by exogenous H(2)O(2). The epicatechin derivatives showed more effective antioxidant properties than epicatechin. Among them, 4beta-(2-aminoethylthio)epicatechin 3-O-gallate showed the highest antioxidant activity against three markers of oxidative stress: hemolysis, lipid peroxidation, and cytotoxicity. Furthermore, as this compound lacks the pyrogallol group on the condensed flavanic structure, it might be safer than other potent gallocatechin-type polyphenols. These findings indicate that these epicatechin derivatives, which are byproducts of the agro-food industry show potential for application in the food and drug industries.
Stability of green tea catechins in commercial tea
leaves during storage for 6 months.
J Food Sci. 2009; Friedman M, Levin CE, Lee SU, Kozukue N. US Dept of Agriculture, Albany, CA, USA.
To help meet the needs of consumers, producers of dietary tea products, and researchers for information on health-promoting tea ingredients, we determined by HPLC 7 catechinsepigallocatechin (EGC), catechin (C), epicatechin, epigallocatechin 3-gallate (EGCG), gallocatechin 3-gallate (GCG), epicatechin 3-gallate (ECG), and catechin 3-gallate (CG)] in samples of 8 commercial green tea leaves of unknown history sold as tea bags in the United States, Korea, and Japan. The samples were stored at 20 degrees C and sampled at 1 wk and 1, 2, 4, and 6 mo. The following ranges in the initial values (0 controls) were observed (in mg/g tea leaves): EGC and C, 0 to trace amounts; epicatechin, 1.9 to 21; EGCG, 13.to 113; GCG, 0.2 to 1.6; ECG, 5 to 50; CG 0.5 to 3; total catechins 36 to 169. Statistical analysis of the results and plots of changes in individual and total catechin levels as a function of storage time indicate a progressive decrease in the content in the total levels, most of which is due to losses in the most abundant catechins, EGCG and ECG. Possible mechanisms of degradations of catechins during storage and the possible significance of the results to consumers of tea are discussed.
Targeted metabolic profiling of phenolics in urine and
plasma after regular consumption of cocoa by liquid chromatography-tandem mass
J Chromatogr A. 2009. Nutrition and Food Science Department, XaRTA, INSA, Pharmacy Faculty, University of Barcelona, 08028 Barcelona, Spain.
The biological properties of cocoa (Theobroma cacao L.) polyphenols are strictly dependent on their bioavailability. A long-term cocoa feeding trial was performed with subjects at high risk for cardiovascular disease. Subjects received two sachets of 20 g of cocoa powder/day with 250 mL of skimmed milk each, or only 500 mL/day of skimmed milk, both for two 4-week periods. The phenolic metabolic profile including phase II conjugated metabolites and phenolic acids derived from the intestinal microbiota was determined by LC-MS/MS in both 24-h urine and fasting plasma. The analysis of 24-h urine revealed significant increases of phase II metabolites, including glucuronides and sulfate conjugates of epicatechin, O-methyl-epicatechin, 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone and 5-(3'-methoxy-4'-hydroxyphenyl)-gamma-valerolactone, after regular cocoa intake. In the case of plasma, only glucuronide conjugates of dihydroxyphenylvalerolactones increased. Regular consumption of cocoa also resulted in a significant increase in the urinary excretion of colonic microbial-derived phenolic metabolites, including vanillic, 3,4-dihydroxyphenylacetic and 3-hydroxyphenylacetic acids, and particularly 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone, whereas only the two latter metabolites showed a significant increase in fasting plasma. The results found herein indicate that 5-(3',4'-dihydroxyphenyl)-gamma-valerolactone and hydroxyphenylacetic acids could be good biomarkers of the regular consumption of cocoa and therefore, of flavanol-rich foods.