Narai-Kanayama Asako, Saruwatari Kosuke, Mori Natsumi, Nakayama Tsutomu
a Graduate School of Veterinary Medicine and Life Science , Nippon Veterinary and Life Science University , Tokyo , Japan.
Biosci Biotechnol Biochem. 2018 Mar;82(3):466-475. doi: 10.1080/09168451.2017.1422967.
Black tea is a highly popular beverage, and its pigments, polymerized catechins such as theaflavins (TFs), are attracting attention due to their beneficial health effects. In this study, to test the inhibitory activities of TFs on the intestinal absorption of cholesterol, we investigated their effects on phosphatidylcholine (PC) vesicles in the absence or presence of a bile salt. (-)-Epicatechin gallate, (-)-epigallocatechin gallate, and TFs formed insoluble complexes with PC vesicles. Galloylated TFs such as TF2A, TF2B, and TF3 precipitated far more than other polyphenols. The subsequent addition of taurocholate redispersed the polyphenol-PC complexes, except that a large amount of TF2A remained insoluble. After incubation with taurocholate-PC micelles, TF2A elevated the turbidity of the micelle solution, providing red sediments. The TF2A-specific effect was dependent on the PC concentration. These results suggest that TF2A interacts with PC and aggregates in a specific manner different from catechins and other TFs.
红茶是一种非常受欢迎的饮品，其色素，如茶黄素（TFs）等聚合儿茶素，因其有益健康的功效而备受关注。在本研究中，为了测试TFs对胆固醇肠道吸收的抑制活性，我们研究了它们在有无胆盐存在的情况下对磷脂酰胆碱（PC）囊泡的影响。（-）-表儿茶素没食子酸酯、（-）-表没食子儿茶素没食子酸酯和TFs与PC囊泡形成不溶性复合物。像TF2A、TF2B和TF3这样的没食子酰化TFs比其他多酚沉淀得更多。随后加入牛磺胆酸盐使多酚-PC复合物重新分散，除了大量的TF2A仍然不溶。与牛磺胆酸盐-PC胶束孵育后，TF2A提高了胶束溶液的浊度，产生红色沉淀。TF2A的特异性作用取决于PC浓度。这些结果表明，TF2A与PC相互作用并以不同于儿茶素和其他TFs的特定方式聚集。
