Simultaneous determination of senkyunolide I and senkyunolide H in rat plasma by LC-MS: application to a comparative pharmacokinetic study in normal and migrainous rats after oral administration of Chuanxiong Rhizoma extract.

A selective liquid chromatographic-mass spectrometric method has been developed and validated for simultaneous determination of senkyunolide I (SEI) and senkyunolide H (SEH) from Chuanxiong Rhizoma in rat plasma. Plasma samples were extracted by liquid-liquid extraction with ethyl acetate and separated on a Kromasil C18 column (250 × 4.6 mm, 5 µm), with methanol-water (55:45, v/v) as mobile phase. The linear range was 0.05-25 µg/mL for SEI and 0.01-5.0 µg/mL for SEH, with lower limits of quantitation of 0.05 and 0.01 µg/mL, respectively. Intra- and inter-day precision were within 10.0 and 9.8%, and the accuracies (relative errors) were <9.6 and 5.9%, with the mean extraction recoveries 81.0-86.6 and 80.5-85.0% for the two anayltes, respectively. The validated method was successfully applied to a comparative pharmacokinetic study of SEI and SEH in normal and migrainous rats after oral administration of Chuanxiong Rhizoma extract. The results indicated that there were obvious differences between normal and migrainous rats in the pharmacokinetic behavior after oral administration of Chuanxiong Rhizoma extract. The absorption of SEI and SEH were significantly increased in migrainous rats compared with normal rats.