Biotransformation of ginsenosides Rb1, Rg3 and Rh2 in rat gastrointestinal tracts

摘要

Background Ginsenosides such as Rb₁, Rg₃ and Rh₂ are major bioactive components of Panax ginseng. This in vivo study investigates the metabolic pathways of ginsenosides Rb₁, Rg₃ and Rh₂ orally administered to rats. Methods High performance liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (MS-MS) techniques, particularly liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS), were used to identify the metabolites. Results Six metabolites of Rb₁, six metabolites of Rg₃ and three metabolites of Rh₂ were detected in the feces samples of the rats. Rh₂ was a metabolite of Rb₁ and Rg₃, whereas Rg₃ was a metabolite of Rb₁. Some metabolites such as protopanaxadiol and monooxygenated protopanaxadiol are metabolites of all three ginsenosides. Conclusion Oxygenation and deglycosylation are two major metabolic pathways of the ginsenosides in rat gastrointestinal tracts.