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CatechinsIn fact, the compound constitutes about 25% of the dry weight of fresh tea leaf. However, that amount varies widely depending on clonal variation, growing location, seasonal / light variation, and altitude . The compound can also be found in human diet from chocolate, fruits, vegetables, and wine. The compound is a powerful polyphenolic antioxidant. In fact, antioxidant potential of both green and black teas, as measured by the Phenol Antioxidant Index, has been found to be significantly higher than that of grape juice and red wines. One of the most bioactive catechins that has been singled out, especially in cancer prevention studies, is epigallocatechin gallate. Much of the studies around the compound are done in the context of tea's health benefits, especially that of Green Tea. However, in particular catechin studies, reduction in atherosclerotic plaques has been seen in animal models, and reduction in carcinogenesis has been found in vitro studies. Catechins - StudiesHammerstone JF, Lazarus SA, Schmitz HH Procyanidin content and variation in some commonly consumed foods. J Nutr, 130, 2086S–2092S (2000). Ruidavets JB, Teissedre PL, Ferrieres J, Carando S, Bougard G, Cabanis JC (2000) Catechin in the Mediterranean diet : vegetable, fruit or wine? Atherosclerosis, 153, 101-117. "Differential effects of green tea-derived catechin on developing versus established atherosclerosis in apolipoprotein E-null mice" Circulation 2004 May 25;109(20):2448-53. "EGCG down-regulates telomerase in human breast carcinoma MCF-7 cells, leading to suppression of cell viability and induction of apoptosis" Int J Oncol. 2004 Mar;24(3):703-10. Hara Y. Influence of tea catechins on the digestive tract. J Cel Biochem 1997; Suppl 27: 52-58. Hibasami H et al. Induction of apoptosis in human stomach cancer cells by green tea catechins. Oncol Repetition 1998; 5:527-29. Hirose M et al. Inhibition of mammary gland carcinogenesis by green tea catechins and other naturally occurring antioxidants in female Sprague-Dawley rats pretreated with MDBA. Cancer Lett 1994; 83:149-56. Naasani I et al. Telomerase inhibition, telomere shortening, and senescence of cancer cells by tea catechins. Biochem Biophys Res Commun 1998; 249:391-96. Sazuka M, Imazawa H, et al. Inhibition of collagenases from mouse lung carcinoma cells by green tea catechins and black tea theaflavins. Biosci Biotechnol Biochem 1997; 61:1504-06. Valcic S et al. Inhibitory effect of six green tea catechins and caffeine on the growth of four selected human tumor cell lines. Anticancer Drugs 1996; 7:461-68.
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