Establishment of LC-MS/MS method for the determination of forsklin in rat plasma and its pharmacokinetics / 国际药学研究杂志

Objective To develop a sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of forsklin in rat plasma.Methods After extraction with methyl tert-butyl ether,chromatographic separation was performed on a C18 column with the mobile phase consisting of water ( 0.1％ formic acid)-acetonitrile in a gradient elution mode.A tandem mass spectrometer equipped with electrospray ionization (ESI) source was used as detector in the positive ion mode.Quantification was performed using multiple reaction monitoring (MRM) with the precursor product combination ions of m/z 411→375.3 and 285→193 for forsklin and diazepam.Results Good linearity was obtained in the 0.5-1000 ng/ml range for the analyte and the analytical method was validated in terms of specificity,precision,accuracy,recovery,stability and matrix effect.These assays gave RSD values always lower than 14.4％ and RE values between -3.5 ％ and 3.8％.In addition,the specificity,extraction recovery,stability and matrix effect were satisfactory.Conclusion Due to its high sensitivity,specificity and simplicity,the method could be used for pharmacokinetic studies of forsklin.

CF mediated G1 arrest is associated with induction of p27(Kip1) and inhibition of cyclin D1 expression in human hepatoma HepG2 cells.

CF is a kind of diterpenoid which was first isolated and purified from Chinese tropical plants by our laboratory. Our previous works have demonstrated it could inhibit the proliferation of several malignant tumor cell lines and stimulate them to differentiate to normal cells. In this article we investigated the effect of CF on human hepatocellulor carcinoma HepG2 cell viability, differentiation, cell cycle distribution and G1 cell cycle related genes expression. We also detected the effect of retinoic acid (RA) which was used as positive control and the effect of combination CF+RA. Our data suggested that CF could be useful to induce growth arrest and differentiation in HepG2 cell lines, and could reverse the transformed phenotype. This anti-tumor effect was due to G1 arrest in cell cycle which was associated with an increase of p27(Kip1) and a decrease of cyclin D1 expression, so CF might be a useful targeted therapy strategy for HCC. Results also showed RA has a different mechanism from CF on G1 arrest, and CF has not synergistic anti-tumor effect with RA on HepG2 treatment.