Pharmacokinetics of eupalinolide A, eupalinolide B and hyperoside from Eupatorium lindleyanum in rats by LC/MS/MS.

A simple, selective, and sensitive LC/MS/MS method was developed and validated for simultaneous determination of eupalinolide A, eupalinolide B, and hyperoside in rat plasma. Plasma samples were processed by protein precipitation with acetonitrile. The three analytes, together with internal standard (IS, lysionotin), were separated on a Venusil MP-C18 column (50mm×2.1mm, 3μm) using a mobile phase of methanol and 10mM ammonium acetate (45:55, v/v) with isocratic elution. Mass spectrometric detection was performed by multiple-reaction monitoring mode via electrospray ionization source. Linear calibration curves were obtained for the following concentration range: 1.28-640ng/mL for EA; 1.98-990ng/mL for EB; and 2.00-1000ng/mL for HYP. The intra- and inter-day precision was less than 10.25%, and the accuracy was between 89.16% and 110.63%. The extraction recovery of the analytes and IS from rat plasma was above 88.75%. The validated method has been successfully applied to pharmacokinetic studies of the three analytes following intragastric administration of Eupatorium lindleyanum extract at a single dose of 100, 250, and 625mg/kg to Sprague-Dawley rats, respectively. The pharmacokinetic results may help to better understand the pharmacological actions of the herb E. lindleyanum.