In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms

The estrogenic activity of 70% EtOH extracts of 32 traditional Chinese medicinal plants, selected according to their reported efficacy for the treatment of menopausal symptoms, was assessed using a recombinant yeast system with both a human estrogen receptor expression plasmid and a reporter plasmid. Among them, 11 (34%) species proved to be active. Polygonum cuspidatum had the highest estrogenic relative potency (RP) (3.28 × 10−3), followed by Rheumpalmatum (3.85 × 10−4), Cassia obtusifolia (3.49 × 10−4), Polygonum multiflorum (2.87 × 10−4), Epimedium brevicornum (2.30 × 10−4), Psoralea corylifolia (1.90 × 10−4), Cynomorium songaricum (1.78 × 10−4), Belamcanda chinensis (1.26 × 10−4), Scutellaria baicalensis (8.77 × 10−5), Astragalus membranaceus (8.47 × 10−5) and Pueraria lobata (6.17 × 10−5). The EC50 value of 17β-estradiol used as the positive control was 0.205 ± 0.025 ng/ml (RP = 100). This study gave support to the reported efficacy of Chinese medicines used for hormone replacement therapy.