In vivo rat metabolism and pharmacokinetic studies of ginsenoside Rg3

Metabolism of an anti-tumor active component of Panax ginseng, ginsenoside (20R)-Rg3, was studied for better understanding its pharmacokinetics in rat. LC-MS was used to determine Rg3 and its metabolites in rat plasma, urine and feces samples. An average half-life of 18.5 min was obtained after the ginsenoside was intravenously dosed at 5 mg/kg. However, Rg3 was not detected in rat plasma collected after oral administration at 100 mg/kg. Only 0.97-1.15% Rg3 of the dosed amount was determined in feces. Hydrolysis and oxygenated metabolites were detected and identified in feces collected after oral administration by using LC-MS and MS-MS.