3.3. α-Glucosidase inhibitory effects of extracts.
α-Glucosidase inhibitory activity was determined by measuring the reduction of 4-nitrophenol from PNPG. With this assay,only the hexane and chloroform extracts were observed to exhibit
α-glycosidase inhibitory activities in dose-dependent manners,and more than 60% inhibition was achieved at the highest concentration of 1000 μg/ml(Fig. 1). α-Glycosidase inhibitory activities of less than 50% were measured at all tested concentrations of the methanol extract and infusion;thus,its EC50 value could not be determined.At concentrations of between 125 and 500 μg/ml, treatment with the hexane extract was found to inhibit α-glycosidase activity by more
than 50%,whereas exposure to the chloroform extract resulted in less than 30% inhibition.Thus,the EC50 value of the hexane extract (117.04 7 2.34 mg/ml) was found to be nearly 10-fold higher than that of the chloroform extract(1030.64713.10 μg/ml).