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 epicatechin gallate
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 epicatechin gallate
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DOI：
10.1021/jf034728l
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发表时间：
2003-12-03
影响因子：
6.1
通讯作者：
Kakuda, T
中科院分区：
文献类型：
--
作者：
Ikeda, I;Kobayashi, M;Kakuda, T
已知茶儿茶素、（-）-表儿茶素（1）、（-）-表没食子儿茶素（2）、（-）-表儿茶素没食子酸酯（3）和（-）-表没食子儿茶素没食子酸酯（4）在巴氏杀菌过程中分别差向异构化为（-）-儿茶素（5）、（-）-没食子儿茶素（6）、（-）-儿茶素没食子酸酯（7）和（-）-没食子儿茶素没食子酸酯（8）。我们以前报道过，茶儿茶素，主要由3和4组成，有效地抑制大鼠胆固醇吸收。在这项研究中，热差向异构儿茶素对胆固醇吸收的影响进行了比较，茶儿茶素。儿茶素和热差向异构儿茶素降低淋巴管胆固醇的大鼠插管在胸导管和差向异构儿茶素比儿茶素更有效。在体外研究中检查了纯化的儿茶素对胆固醇胶束溶解度的影响。儿茶素没食子酸酯的加入通过从胆盐胶束中沉淀胆固醇来降低胆固醇的胶束溶解度。化合物7和8分别比化合物3和4更有效地沉淀胆固醇。这些观察结果强烈表明，热差向异构儿茶素可能比茶儿茶素更低胆固醇血症。
It has been known that tea catechins, (-)-epicatechin (1), (-)-epigallocatechin (2), (-)-epicatechin gallate (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 cholesterol absorption in rats. In this study, the effect of heat-epimerized catechins on cholesterol absorption was compared with tea catechins. Both tea catechins and heat-epimerized catechins lowered lymphatic recovery of cholesterol in rats cannulated in the thoracic duct and epimerized catechins were more effective than tea catechins. The effect of purified catechins on micellar solubility of cholesterol was examined in an in vitro study. The addition of gallate esters of catechins reduced micellar solubility of cholesterol by precipitating cholesterol from bile salt micelles. Compounds 7 and 8 were more effective to precipitate cholesterol than 3 and 4, respectively. These observations strongly suggest that heat-epimerized catechins may be more hypocholesterolemic than tea catechins.