Yang Xiaoping, Kong Fanbin
Key Laboratory of Horticultural Plant Biology, Huazhong Agricultural University, Ministry of Education, Wuhan 430070, P.R. China.
Department of Food Science and Technology, College of Agricultural and Environmental Sciences, The University of Georgia, Athens, Georgia, USA.
J Sci Food Agric. 2016 Feb;96(3):777-82. doi: 10.1002/jsfa.7147. Epub 2015 Mar 31.
The objective of this study was to determine whether green tea, black tea and oolong tea have inhibitory potential against α-glucosidase which may be used to control postprandial hyperglycemia in type 2 diabetes mellitus.
Green tea polyphenols (TPs) strongly inhibited α-glucosidase activity by non-competitive inhibition with an IC50 value of 2.33 µg mL(-1) and the inhibitory effect was dependent on TP concentration and incubation order. Green tea, black tea and oolong tea also had dose-dependent inhibitory potential with IC50 values of 2.82, 2.25 and 1.38 µg mL(-1) (µg polyphenol mL(-1)), respectively. The study also showed that the content of unprecipitated TPs changed during enzymatic hydrolysis, leading to the change of the antioxidant activity. The change of the antioxidant activity of tea extracts revealed a similar trend to that of green TPs during enzymatic hydrolysis.
Green TPs, green tea, black tea and oolong tea are excellent α-glucosidase inhibitors and their inhibitory potency is mainly attributed to TPs. These findings suggest that green tea, black tea and oolong tea can potentially be used to control postprandial hyperglycemia.
本研究的目的是确定绿茶、红茶和乌龙茶是否具有抑制α-葡萄糖苷酶的潜力，这可能用于控制2型糖尿病患者的餐后高血糖。
绿茶多酚（TPs）通过非竞争性抑制强烈抑制α-葡萄糖苷酶活性，IC50值为2.33 µg mL(-1)，抑制作用取决于TP浓度和孵育顺序。绿茶、红茶和乌龙茶也具有剂量依赖性抑制潜力，IC50值分别为2.82、2.25和1.38 µg mL(-1)（µg多酚mL(-1)）。该研究还表明，未沉淀的TPs含量在酶水解过程中发生变化，导致抗氧化活性改变。茶提取物抗氧化活性的变化在酶水解过程中与绿茶TPs呈现相似趋势。
绿茶TPs、绿茶、红茶和乌龙茶是优秀的α-葡萄糖苷酶抑制剂，它们的抑制效力主要归因于TPs。这些发现表明，绿茶、红茶和乌龙茶可能可用于控制餐后高血糖。
