Simultaneous quantification of ginsenoside Rg1 and its metabolites by HPLC-MS/MS: Rg1 excretion in rat bile, urine and feces

Ginsenoside Rg1 (Rg1), the major effective component of ginseng, has been shown to have multiple bioactivities, but low oral bioavailability. The aim of this study was to develop a simple, sensitive and rapid high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) method, which could be used to validate and quantify the concentrations of Rg1 and its metabolites in Sprague-Dawley rat bile, urine, and feces after oral administration (25 mg/kg). Calibration curves offered satisfactory linearity (r> 0.995) within the determined ranges. Both intra-day and inter-day variances were less than 15%, and the accuracy was within 80-120%. The excretion recoveries of Rg1, ginsenoside Rh1 (Rh1), and protopanaxatriol (Ppt) in bile, urine, and feces combined were all greater than 70%. The fecal excretion recoveries of Rg1, Rh1, and Ppt were 40.11%, 22.19%, and 22.88%, respectively, whereas 6.88% of Rgl and 0.09% of Rhl were excreted in bile. Urinary excretion accounted for only 0.04% of Rgl. In conclusion, the observed excretion profiles for Rg1 and its metabolites after oral administration are helpful for understanding the poor oral bioavailability of Rgl and will aid further investigations of Rgl as a pharmacologically active component. (C) 2016 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND