[Pharmacokinetics of luteolin from Elsholtzia blanda extracts in rats].

An RP-HPLC method for determination of luteolin from Elsholtzia blanda Benth. extracts in rats' plasma was established and the pharmacokinetics of luteolin in rats was studied. Drug blood samples from caudal vein were gotten after oral administration of luteolin. Plasma samples were determined by RP-HPLC after being deproteinized with trichloroacetic acid and extracted with ethyl acetate. The calibration curve was linear in the range of 0.37-47.27 microg x mL(-1). The limit of quantification was 0.37 microg x mL(-1). The method recovery of luteolin was 93%-99%. The extract recovery was 75%-85%. RSDs of intra-and inter-day precisions were less than 5%. The concentration-time curve of luteolin after oral administration of Elsholtzia blanda Benth. extracts was fitted to two compartment open model. Two factors analysis of variance were adopted in the evaluation of gender and time spots for collection of blood. The result suggested that the gender-based difference in blood-drug concentrations had statistical significance. The metabolite in blood was identified as galcuronide. The method is sensitive, specific, accurate, and is appropriate for determination of luteolin in vivo.