[Screening of antineoplastic components in Radix et Rhizoma Rhei using chromatographic fingerprints].

A new strategy for screening of antineoplastic components in the traditional Chinese medicine of Radix et Rhizoma Rhei has been developed using chromatographic fingerprints before and after metabolism by high performance liquid chromatography-mass spectrometry. The metabolizing method was established based on the in vitro metabolism by Sprague-Dawley (SD) rat liver homogenate. By means of the metabolism methods in vitro, the antineoplastic activity of the extracts, metabolites and components of Radix et Rhizoma Rhei were determined by microculture tetrazolium (MTT) assays in vitro. It was observed that the inhibition rate of the crude extract for HeLa cell was increased from 26.7% to 36.2% after 60 min of metabolism. The changes of activities resulted from the changes of components' structures and the bioactive components were discovered simultaneously in view of metabolism by inhibiting rate assay for the components in Radix et Rhizoma Rhei. It is concluded that the antineoplastic activity of the crude extract from Radix et Rhizoma Rhei was increased after in vitro metabolism because the antineoplastic activity of aloe-emodin, the metabolite of chrysophanol, is higher than its parent compounds.