Inhibitory effect of steviol, a metabolite of stevioside, on glucose absorption in everted hamster intestine in vitro

Abstract

The effects of stevioside and steviol (a product of enzymatic hydrolysis of stevioside) on intestinal glucose absorption were examined in hamster jejunum. By using the everted sac technique, we found that stevioside (1 and 5 mM) had no inhibitory effect on glucose absorption. In contrast, glucose absorption was inhibited 29% by 1 mM steviol. The inhibition of glucose absorption by steviol was related to steviol concentration and incubation time. The possible mechanism of steviol inhibitory action of glucose absorption was also investigated. Reductions in the intestinal mucosal ATP content and absorptive surface area were responsible for the inhibition of glucose absorption by steviol. The decrease in the intestinal mucosal ATP content was accompanied by a decrease in the activities of mitochondrial NADH cytochrome c reductase and cytochrome oxidase. Morever, no inhibitory effects of steviol on the activity of intestinal Na +,K +-ATPase and glucose uptake in the intestinal brush-border membrane vesicles were seen. These results suggest that inhibition of intestinal glucose absorption by steviol in hamsters is due to the reduction in mucosal ATP content and an alteration of the morphology of the intestinal absorptive cells.