Effect of a Disaccharidase Inhibitor, AO-128, on Postprandial Hyperglycemia in Rats

Abstract

The inhibitory actions of AO-128, an N-substituted derivative of valiolamine, on intestinal α-, glucosidase activity and postprandial hyperglycemia were examined in rats. AO-128 showed about 2Q-30-fold more potent inhibition of semi-purified parcine small intestine disaccharidases and about 190-3, 900-fold more potent inhibition of purified rat small intestine sucrase-isomaltase (S-I) complex than acarbose, a typical α-glucosidase in hibitor. on the other hand, the inhibitory activity of AO-128 on α-amylase was only 1/3, 400 that of acarbose. AO-128 suppressed the elevation of blood glucose after oral administration of sucrose, maltose or starch, but had no effect on the elevation due to ingestion af glucose, fructose or lactose, In rats receiving AO-128, adipose tissue weight was reduced, and intestinal disaccharidase activities were inhibited completely, even though the S-I complex content was increased.