RESUMO
αglucosidase is a key enzyme that plays a role in glucose absorption in the gastrointestinal tract, and the inhibition of its activity induces the prevention of postprandial hyperglycemia. Several αglucosidase inhibitors have been used as medicines for type 2 diabetes, but a similar effect is observed in natural resources, including traditional herbs and their phytochemicals. To identify the presence of the αglucosidase inhibitory activity in herbs, in which various functional effects have been known to occur, the present study investigated the effects of hotwater extracts of 26 types of herbs on αglucosidase activity in an in vitro assay. The results indicated significant increases in the inhibition of αglucosidase activity in 1,000 µg/ml olive (P<0.01), white willow (P<0.01) and red rooibos hotwater extracts. Furthermore, ≥50% inhibition of αglucosidase activity was determined to be significant in 1,000 µg/ml coltsfoot, green tea and bearberry hotwater extracts. In addition, the effects of bearberry, green tea and coltsfoot hotwater extracts on αglucosidase activity in vivo were evaluated according to the blood glucose levels (BGLs) in maltose and glucose load model rats. It was indicated that the administration of these three herb extracts significantly reduced the increasing BGLs after maltose loading until 0.5 h compared with the control group. However, only coltsfoot extract significantly reduced the increasing BGLs after glucose loading until 0.5 h compared with the control group. Thus, the present results may facilitate the understanding of a novel functionality in traditional herbs, which could be useful for the prevention of disease onset and progression, such as in hyperglycemia and type 2 diabetes.