Assessment of the Aromatase Inhibitory Activity of Ma-Huang-Tang (MHT) and Its Active Compounds.

ABSTRACT

Aromatase, a cytochrome P450 enzyme that converts androgens into estrogens, is an important drug target for hormone-dependent diseases. The purpose of this study was to elucidate the aromatase inhibitory effects of Ma-Huang-Tang (MHT), a traditional Korean herbal medicine prescription, and to identify its active ingredients. In this study, the inhibitory effect of MHT on aromatase activity was observed using dibenzylfluorescein (DBF) and KGN cells, and the dose-dependent effect of MHT was verified (IC50 values of 251 µg/mL and 246 µg/mL as determined by the two methods, respectively). Furthermore, among the six herbal medicines that constitute MHT, Ephedrae Herba, Cinnamomi Ramulus, and Glycyrrhizae Radix et Rhizoma showed the most potent inhibition of aromatase activity. Furthermore, upon identification of the active MHT compounds, three markers from Glycyrrhizae Radix et Rhizoma, liquiritin (5), liquiritin apioside (6), and liquiritigenin (7), were verified (IC50 values of 530 µM, 508 µM, and 1.611 mM and 499 µM, 522 µM, and 1.41 mM as determined by the two methods, respectively). In addition, their contents were confirmed to be 15.58, 19.80, and 2.22 mg/g, respectively, by HPLC/DAD analysis. These results indicate that the aromatase inhibitory effect of MHT results from the synergistic action of its active components and that MHT has potential as a preventive agent against aromatase activity.