[Study on pharmacokinetics of asperosaponin VI and its active metabolite in rats]

To study the pharmacokinetics, excretion characteristics and plasma protein binding rate of asperosaponin VI (A-VI) and its active metabolite hederagenin (M1). A-VI and M1 concentrations in plasma, bile, urine and feces were determined by established LC-MS/MS to calculate the pharmacokinetic parameters. The plasma protein binding rate of A-VI was determined by equilibrium dialysis method. the double peaks was observed in the A-VI plasma concentration-time curve, after rats were orally administered with low, medium and high doses of A-VI (0.03, 0.09, 0.27 g x kg(-1)). The Cmax1 and Cmax2 of A-VI were (28.88 +/- 49.78) and (4.480 +/- 1.872) microg x L(-1), (35.19 +/- 23.53) and (22.11 +/- 16.15) microg x L(-1), (73.37 +/- 37.28) and (132.2 +/- 160.7) microg x L(-1), respectively. The AUC0-t, of A-VI were (43.21 +/- 37.32), (133.9 +/- 102.5) and (779.6 +/- 876.9) microg x h x L(-1), respectively. The t1/2 of A-VI were (3.3 +/- 0.8), (3.2 +/- 2.3) and (4.5 +/- 1.2) h, respectively. The Cmax of M1 were (16.03 +/- 9.336), (26.41 +/- 11.95) and (28.71 +/- 5.874) microg x L(-1), respectively. The AUC0-t, of M1 were (105.6 +/- 73.60), (260.0 +/-153.9) and (323.1 +/- 107.9) microg x h x L(-1), respectively. The t1/2 of M1 were (4.1 +/- 3.4), (4.4 +/- 2.3), (3.9 +/- 0.9) h, respectively. No significant gender difference was found in the in vivo pharmacokinetics of A-VI and M1. There was no accumulation of A-VI and M1 after multiple administrations of A-VI (0.09 g x kg(-1)). After oral administration of A-VI, the double peaks were also observed in biliary and urinary excretion rate-time curves for A-VI. M1 was detected in the feces samples at 6 h after oral administration. The average plasma protein binding rate of A-VI was 92. 9% in rats.