The effect of herbal medicine baicalin on pharmacokinetics of rosuvastatin, substrate of organic anion-transporting polypeptide 1B1.

ABSTRACT

The aim of this study was to explore potential herb-drug interaction between baicalin and rosuvastatin, a typical substrate for organic anion-transporting polypeptide 1B1 (OATP1B1) related to different OATP1B1 haplotype groups. Eighteen unrelated healthy volunteers who were CYP2C9*1/*1 with different OATP1B1 haplotypes (six OATP1B1*1b/*1b, six OATP1B1*1b/*15, and six OATP1B1*15/*15) were selected to participate in this study. Rosuvastatin (20 mg orally) pharmacokinetics after coadministration of placebo and 50-mg baicalin tablets (three times daily orally for 14 days) were measured for up to 72 h by liquid chromatography-mass spectrometry in a two-phase randomized crossover study. After baicalin treatment, the area under the plasma concentration-time curve (AUC)(0-72) and AUC(0-infinity) of rosuvastatin decreased by 47.0+/-11.0% (P=0.001) and 41.9+/-7.19% (P=0.001) in OATP1B1*1b/*1b, 21.0+/-20.6% (P=0.035) and 23.9+/-8.66% (P=0.004) in OATP1B1*1b/*15, and 9.20+/-11.6% (P=0.077) and 1.76+/-4.89% (P=0.36) in OATP1B1*15/*15, respectively. Moreover, decreases of both AUC(0-72) and AUC(0-infinity) of rosuvastatin among different haplotype groups were significantly different (P=0.002 and <0.001). Baicalin reduces plasma concentrations of rosuvastatin in an OATP1B1 haplotype-dependent manner.