OBJECTIVETo develop a LC-MS method for the determination of senkyunolide I (SI) in rat plasma, in order to observe whether there is significant change in the pharmacokinetics parameters of complex prescriptions of Huoluoxiaolingdan (HLXL) and single herbal extracts from Ligusticum chuanxiong Hort. in rats, and assess the effect of other components in HLXL on the pharmacokinetics of SI.

METHODTwelve male Sprague-Dawley (SD) rats were randomly divided into two groups, and orally administered with extract from HLXL and L. chuanxiong (both equal to SI 4.53 mg x kg(-1)). Their blood was collected at different time points for LC-MS, in order to detect the plasma concentration of SI. The pharmacokinetic parameters of SI were calculated by DAS 2.0 software. SPSS 16.0 software was used for independent-sample T-test and Nonparametric T-test.

RESULTA linear relationship of SI ranged from 6.750 to 675.0 microg x L(-1), and with the lowest limit of detection being 6.750 microg L(-1). Both of the plasma concentration-time curves of SI were fitted with the two-compartment model for extract of HLXL and L. chuanxiong. The detected AUC and Cmax of SI showed significant difference, with no significant difference in other parameters.

CONCLUSIONThe LC-MS determination method established in this experiment was so exclusive, accurate and sensitive that it is suitable for pharmacokinetic studies on extracts of HLXL and SI from L. chuanxion. The experiment results show that other ingredients of HLXL have noticeable effect on the absorption of SI in rat plasma.