Pharmacokinetic Study on Different Compatibilities of Zhizi Bopi Decoction in Rats

Abstract:

Objective: To obtain pharmacokinetics parameters of geniposide in pure geniposide, Gardeniae Fructus(ZZ), ZZ-Phellodendri Chinensis Cortex(HB), ZZ-Glycyrrhizae Radix et Rhizoma(GC) and Zhili Bopi decoction(ZZBPD) and to investigate the effect of the different recipes of ZZBPD on the pharmacokinetics of geniposide. Method: Thirty rats were randomly divided into five groups, and were administered pure geniposide, ZZ, ZZ-HB, ZZ-GC and ZZBPD, respectively. The plasma concentration of four recipes at 0.08, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10 h were determined by HPLC, and the pharmacokinetics parameters of geniposide in these recipes were consequently computed by software program 3P97. Result: The differences of the predominant parameters of geniposide in rat plasma of the five groups were considered to be noticeable (P<0.05). Compared to administration of geniposide alone, the pharmacokinetic parameters (AUC_0-t, AUC_0-∞, T_1/2) were remarkably enhanced following oral administration of ZZ, ZZ-HB, ZZ-GC, ZZBPD. The C_max, T_1/2, AUC_0-t and AUC_0-∞ of ZZBPD were remarkably enhanced compared to other four groups. The AUC_0-t, AUC_0-∞, T_1/2 of ZZ-HB, ZZ-GC and ZZBPD were higher than ZZ. The T_max of ZZ-GC and ZZBPD were longer than ZZ and ZZ-HB. Conclusion: Different recipes of ZZBPD had different impact on the pharmacokinetics of geniposide. The bioavailability of geniposide in decoctions were higher than in monomer and the bioavailability of geniposide in ZZBPD was higher than other groups. It can be deduced that herb-herb interaction may increase the absorption, delay the elimination, and significantly improve the oral bioavailability of geniposide in rats.