Combined effects of green tea extracts, green tea polyphenols or epigallocatechin gallate with acarbose on inhibition against α-amylase and α-glucosidase in vitro.
Green tea, green tea polyphenols and epigallocatechin gallate (EGCG) are confirmed to have beneficial effects in the treatment of diabetes mellitus, and a possible mechanism can be ascribed to their inhibitory effect against α-amylase and α-glucosidase in the digestive tract. In this paper, we first investigated the combined inhibitory effect of green tea extracts, green tea polyphenols or EGCG with acarbose on α-amylase and α-glucosidase in vitro. Our results indicated that the interaction between green tea extracts (green tea polyphenols or EGCG) and acarbose was complicated. The combination of green tea extracts, green tea polyphenols or EGCG with acarbose had a synergistic effect on α-amylase and α-glucosidase at low concentrations and the combined effect turned out to be antagonistic at high concentrations according to the Combination Index (CI) values. These findings not only provided some significant quantitative values, but also provide some valuable implications for the combined use of acarbose and GTE (GTP or EGCG) in the treatment of diabetes mellitus.
Department of Tea Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, Zhejiang, China. zdxp@zju.edu.cn.
Junjie
J
Gao
Ping
P
Xu
Yuefei
Y
Wang
Yiqi
Y
Wang
Danielle
D
Hochstetter
D020909:Acarbose / Q000737:chemistry; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000737:chemistry; D065089:Glycoside Hydrolase Inhibitors; D006801:Humans; D007004:Hypoglycemic Agents / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry*; D000516:alpha-Amylases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D000520:alpha-Glucosidases / Q000737:chemistry
D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D059808:Polyphenols; D002392:Catechin; C045651:epigallocatechin gallate; D000516:alpha-Amylases; D000520:alpha-Glucosidases; D020909:Acarbose