Heat-Epimerized Tea Catechins Rich in Gallocatechin Gallate and Catechin Gallate Are More Effective To Inhibit Cholesterol Absorption than Tea Catechins Rich in Epigallocatechin Gallate and Epicatechi

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• 作者：Ikuo Ikeda ; Makoto Kobayashi ; Tadateru Hamada ; Koichi Tsuda ; Hitomi Goto ; Katsumi Imaizumi ; Ayumu Nozawa ; Akio Sugimoto ; and Takami Kakuda
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2003
• 出版时间：December 3, 2003
• 年：2003
• 卷：51
• 期：25
• 页码：7303 - 7307
• 全文大小：82K
• 年卷期：v.51,no.25(December 3, 2003)
• ISSN：1520-5118

文摘

It has been known that tea catechins, (-)-epicatechin (1), (-)-epigallocatechin (2), (-)-epicatechingallate (3), and (-)-epigallocatechin gallate (4) are epimerized to(-)-catechin (5), (-)-gallocatechin(6), (-)-catechin gallate (7), and (-)-gallocatechin gallate (8), respectively, during retort pasteurization.We previously reported that tea catechins, mainly composed of 3 and 4, effectively inhibit cholesterolabsorption in rats. In this study, the effect of heat-epimerized catechins on cholesterol absorptionwas compared with tea catechins. Both tea catechins and heat-epimerized catechins lowered lymphaticrecovery of cholesterol in rats cannulated in the thoracic duct and epimerized catechins were moreeffective than tea catechins. The effect of purified catechins on micellar solubility of cholesterol wasexamined in an in vitro study. The addition of gallate esters of catechins reduced micellar solubilityof cholesterol by precipitating cholesterol from bile salt micelles. Compounds 7 and 8 were moreeffective to precipitate cholesterol than 3 and 4, respectively. These observations strongly suggestthat heat-epimerized catechins may be more hypocholesterolemic than tea catechins.Keywords: Catechin gallate; cholesterol absorption; epicatechin gallate; epigallocatechin gallate;gallocatechin gallate; rats