Abstract: The metabolism of shikonin in rats was studied. Shikonin was administered (i.p.) to healthy, male Wistar rats pretreated with phenobarbital (PB, i.p., 60 mg·kg^-1, once a day, 3 d) by asingle dose of 20 mg·kg^-1, urine and bile were collected. The bile and urine samples wererespectively hydrolyzed with β-glucuronidase, extracted with ethyl acetate and the extractive concentrated in vacuum. The residues were dissolved in methanol and analyzed by a RP-HPLC/DADsystem for identification of shikonin metabolites. It has been proved that shikonin is metabolizedvery fast in the body and the metabolites are excreted mainly throngh the bile. The chromatograms and spectra showed that there were ten shikonin metabolites with similar UV spectra in the bile andurine respectively. The difference between in vivo and in vitro metabolic profiles of shikonin wasalso discussed.

Key words: Shikonin, In vivo metabolism, RP-HPLC, DAD