The Inhibitory Effects Of Water And Ethanol Extracts Of Chinese Propolis On α-Glucosidase And Postgrandial Blood Glucose

The present study examined the inhibitory effects of water extract (WEP) and ethanol extract (EEP) of Chinese propolis on activities of α-Glucosidase which is responsible for digestion of carbohydrate to monosaccharides in the process of intestinal absorption. By Comparing two different extracts from propolis, we found that both of them had significant inhibition on α-Glucosidase in a dose-dependent manner in vitro. Both WEP and EEP's inhibition on α-Glucosidase was determined to be competitive and reversible when the enzyme-substrate mixture was simultaneously treated with WEP or EEP. In addition, when it was orally administered to mouse with sucrose (2g/kg), WEP (6-24mg/kg) or EEP (6-24mg/kg) significantly suppressed the increase of blood glucose levels after sucrose loaded in a dose dependent manner. Moreover, by using WEP (12mg/kg) or EEP (12mg/kg) for continuing gastric incubation for 6 days, both could also inhibit the increase of blood glucose levels after glucose (2g/kg) was loaded to mouse. These results suggested that both WEP and EEP might exert anti-diabetic effect by suppressing carbohydrate absorption from intestine possibly through inhibition of α-Glucosidase.