Effect of paeoniflorin on the pharmacokinetics of glycyrrhizic acid and glycyrrhetinic acid in rats / 中国药学杂志

ABSTRACT

OBJECTIVE: To explore the effect of paeoniflorin on the pharmacokinetics of glycyrrhizic acid and its active metabolite glycyrrhetinic acid after oral administration. METHODS: After the administration of glycyrrhizic acid alone or with paeoniflorin, blood samples were collected, and the plasma concentration-time profiles of glycyrrhizic acid and glycyrrhetinic acid were established. Pharmacokinetic parameters were calculated and analyzed with Topfit 2.0 software. RESULTS: When glycyrrhizic acid was co-administered with paeoniflorin, the ρmax and AUC of glycyrrhizic acid decreased to 9% and 33% of those of glycyrrhizic acid administered alone, respectively; the tmax prolonged markedly, CL increased, and Vd became larger. For glycyrrhetinic acid, only the t1/2 prolonged significantly while other PK parameters had little change. CONCLUSION: Paeoniflorin dramatically inhibits the absorption rate and extent of glycyrrhizic acid in rats when simultaneously orally administered, but has only small effect on the absorption of glycyrrhetinic acid. Copyright 2012 by the Chinese Pharmaceutical Association.