Pharmacokinetic studies of super(131)I-stevioside and its metabolites

Stevioside is 300 times sweeter than sucrose and it has been employed as a non-caloric sweetener in Brazil, Japan and other countries. The toxicity of stevioside has been extensively investigated. super(131)I-stevioside (1.10 MBq) was injected i.v in Wistar male rats, in distribution in the body and metabolism were studied. The highest concentration of radioactivity was observed in the liver and in the small intestine after 10 and 120 minutes, respectively. At 2 h after injection, the radioactivity eliminated in the bile was 52.0% of the original dose. The results of RP-HPLC analysis of the bile showed that stevioside was degraded in vivo and that steviol appeared as a major metabolite. However, in the urine; RP-HPLC analysis did not show the presence of steviol.