Abstract
For the purpose of evaluating phytoestrogenic activity of medicinal plant extracts, a naringinase-pretreatment method was developed, monitoring with proliferation of MCF-7 human breast cancer cells and induction of β-galactosidase in a yeast two-hybrid assay system. Of various medicinal plant extracts examined, the extracts of Alpinia katsumadai (seeds), Glycyrrhiza uralensis (roots) and Moghania philippinensis (roots) showed higher estrogenic activity by per-treatment with naringinase than the original extract themselves. The contents of liquiritigenin and isoliquiritigenin having potent estrogenic activity, appreciably increased after the naringinase treatment of the extract of G. uralensis. These findings suggested that orally administered crude drugs would increase their estrogenic activity, due to the hydrolysis of some glycosylated constituents by intestinal flora.
