New glucogenesis inhibition model based on complete alpha-glucosidases from rat intestinal tissues validated with various types of natural and pharmaceutical inhibitors

Abstract

BACKGROUND: Inhibition of intestinal alpha-glucosidases from rat intestinal acetone powder (RIAP) has been widely used in research focused on regulating glucogenesis to be applied as a strategy to control obesity and type II diabetes. However, the crude extract has different compositions of alpha-glucosidases than a complete RIAP suspension due to enzymes anchored on the intestinal tissues after the extraction. Here, the inhibitory effects of different pharmaceutical and food-grade inhibitors on the enzymes in the RIAP suspension were investigated. RESULTS: Instead of crude extracts from RIAP, the RIAP suspension without the extraction process was applied to optimize the alpha-glucosidase inhibitory model by pharmaceutical/natural inhibitors. The results clearly showed that the half-maximal inhibitory concentration ratios of four individual alpha-glucosidases by various inhibitors were different between the RIAP suspension and the crude extract. In particular, isomaltase from the RIAP suspension required more inhibitors than the crude extraction did, as this enzyme is still anchored to the remaining intestinal tissue from the extraction process. CONCLUSION: The crude extract from RIAP contains only a portion of the enzymes, which poses limitations for determining the precise inhibitory properties by various types of enzyme inhibitors. On the contrary, an in vitro assay with RIAP suspension that has all the alpha-glucosidases is a more suitable method for determining digestibility of glycemic carbohydrates. This new approach can be applied to the development of natural/synthetic alpha-glucosidase inhibitors to attenuate the postprandial glycemic response more accurately. (C) 2022 Society of Chemical Industry.