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 CCl-induced hepatic injury rats. With norisoboldine as an internal standard, chromatographic separation was performed on a C 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. The lower limit of quantification was 50 ng·mL. The developed method was successfully applied to a study of the pharmacokinetic difference of bergenin (100 mg·kg) 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 of bergenin in hepatic injury rats was elevated to 2.11-fold and C 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.