INHIBITORY EFFECT OF STEVIOL, A METABOLITE OF STEVIOSIDE, ON GLUCOSE-ABSORPTION IN EVERTED HAMSTER INTESTINE IN-VITRO

The effects of stevioside and steviol (a product of enzymatic hydrolys is of stevioside) on intestinal glucose absorption were examined in ha mster jejunum. By using the everted sac technique, we found that stevi oside (1 and 5 mM) had no inhibitory effect on glucose absorption. In contrast, glucose absorption was inhibited 29% by 1 mM steviol. The in hibition of glucose absorption by steviol was related to steviol conce ntration and incubation time. The possible mechanism of steviol inhibi tory action of glucose absorption was also investigated. Reductions in the intestinal mucosal ATP content and absorptive surface area were r esponsible for the inhibition of glucose absorption by steviol. The de crease in the intestinal mucosal ATP content was accompanied by a decr ease in the activities of mitochondrial NADH cytochrome c reductase an d cytochrome oxidase. Morever, no inhibitory effects of steviol on the activity of intestinal Na+,K+-ATPase and glucose uptake in the intest inal brush-border membrane vesicles were seen. These results suggest t hat inhibition of intestinal glucose absorption by steviol in hamsters is due to the reduction in mucosal ATP content and an alteration of t he morphology of the intestinal absorptive cells.