Metabolic profiling of Gynostemma pentaphyllum extract in rat serum, urine and faeces after oral administration.

Folk drug Gynostemma pentaphyllum (Thunb.) Makino contains many biologically active phytochemicals which have been demonstrated to be effective against chronic diseases. As in vivo anti-tumor experiments of G. pentaphyllum extract (GP) show much stronger antitumor activities than in vitro, it is important and necessary to understand the metabolic study of GP. A sensitive and specific U-HPLC-MS method was utilized for the first time to rapidly identify gypenosides and its possible metabolites in rat serum, urine, and faeces after oral administration. Solid phase extraction was utilized in the sample preparation. Negative Electrospray ionisation (ESI) mass spectrometry was used to discern gypenosides and its possible metabolites in rat samples. As a result, after oral administration, a total of seven metabolites of G. pentaphyllum extract were assigned, two from the rat serum and seven both from the rat urine and faeces. As metabolites of G. pentaphyllum extract, all of them have never been reported before.