Comparative pharmacokinetics of bergenin, a main active constituent of Saxifraga stolonifera Curt., in normal and hepatic injury rats after oral administration.

Bergenin, isolated from the herb of Saxifrage stolonifera Curt. (Hu-Er-Cao) has hepatoprotective, anti-inflammatory, antitussive, and neuroprotective activities. The aim of the present study was to establish a simple, rapid, and sensitive RP-HPLC method for determination of bergenin in rat plasma and compare its oral pharmacokinetic behaviors in normal and CCl4-induced hepatic injury rats. With norisoboldine as an internal standard, chromatographic separation was performed on a C18 analytical column with acetonitrile and water (11 : 89, V/V) containing 0.1% formic acid as the mobile phase. A good linearity was obtained over the range of 100-10 000 ng·mL-1. The lower limit of quantification was 50 ng·mL-1. The developed method was successfully applied to a study of the pharmacokinetic difference of bergenin (100 mg·kg-1) between normal and hepatic injury rats after oral administration. Marked alterations of pharmacokinetic parameters in hepatic injury rats were observed. Compared to normal rats, the AUC(0-∞) of bergenin in hepatic injury rats was elevated to 2.11-fold and Cmax was increased by 130%, whereas CL value was only 55% of the normal rats, suggesting that the systemic exposure of bergenin was significantly increased under hepatic injury status.