文献类型：期刊文献

英文题名：Catechins play key role in green tea extract-induced postprandial hypoglycemic potential in vitro

作者：Xu, Ying[1];Zhang, Zhang[2];Li, Lin[2];Joshi, Manoj Kumar[2];Huang, Nan[2];Niu, Jianglong[1];Lu, Yanhua[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Unilever R&D Ctr, Shanghai 200335, Peoples R China

年份：2013

卷号：237

期号：2

起止页码：89

外文期刊名：EUROPEAN FOOD RESEARCH AND TECHNOLOGY

收录：;EI(收录号：20133116571632);WOS:【SCI-EXPANDED(收录号:WOS:000322260200001)】；

基金：This work was supported by "the Fundamental Research Funds for the Central Universities," and partially supported by Shanghai Leading Academic Discipline Project (B505) and the National Special Fund for State Key Laboratory of Bioreactor Engineering (2060204).

语种：英文

外文关键词：Green tea; Catechins; alpha-Glucosidase; alpha-Amylase; Glucose transport; Postprandial hypoglycemic

摘要：Green tea is often associated with glycemic control benefit. However, the available evidence is not conclusive. In this study, we systematically assessed the contribution of main green tea extract (GTE) ingredients to the inhibition of carbohydrate digestive enzyme and intestinal glucose transport, which are two intervention options for postprandial blood glucose control. A catechin mixture (CM) solution containing seven catechins and epigallocatechin gallate (EGCG) solution was prepared based on the contents of individual catechins in the GTE as determined by high-performance liquid chromatography. The inhibitory potency of GTE, CM, and EGCG on alpha-amylase or alpha-glucosidase was compared in cell-free system. GTE's inhibitory potency was mainly attributed to catechins, among which, EGCG accounted for at least 80 % of the alpha-amylase inhibitory activity and 90 % of the alpha-glucosidase inhibitory activity of GTE. In addition, the fluorescence quenching of the digestive enzymes by EGCG revealed that the binding site of EGCG-alpha-amylase was 1.2, and that for EGCG-alpha-glucosidase to be 2.0. The inhibitory potency of GTE, CM, and EGCG on glucose transport was assessed in Caco-2 monolayer system. Under the simulated fasting state, there was significant difference between the test materials regarding inhibitory potency according to two-way ANOVA (P > 0.05). Under the simulated fed state, CM showed stronger inhibition than EGCG only at the highest test concentration (25.7 mu g/mL), while no significant difference was observed between CM and the GTE. In conclusion, our results suggest that green tea's postprandial hypoglycemic potential can be attributed to its catechins.