Stevioside is not metabolized in the isolated perfused rat liver.

Stevioside, the sweet glycoside of Stevia rebaudiana, was perfused in to rat livers in order to see if, according to previous suggestions, the hepatic tissue is able to metabolize this compound. Stevioside, at the concentrations of 0.2 and 0.5 mM, was recirculated during two hours. The concentration of stevioside remained constant during the whole perfusion time. The possible formation of hydrolysis products, especially steviol, was investigated chromatographically, with negative results. It can be concluded that the reported metabolic transformation of intravenously injected [131I]iodine-stevioside is either a specific characteristic of this derivative or depends on factors that are absent in the isolated perfused rat liver.