RESUMEN
OBJECTIVE: Regarding the growing use of alternative therapies for peri- or postmenopausal symptoms, we evaluated the effect of a water extract of Angelica sinensis (dong quai), used for peri- or postmenopausal relief, on the proliferation of estrogen receptor-positive (MCF-7) and negative (BT-20) breast cancer cells in vitro. DESIGN: The present study was designed to investigate the growth-modulating effect of dong quai water extract, alone or in the presence of 17beta-estradiol and 4-hydroxytamoxifen, on MCF-7 and BT-20 cell cultures using MTT proliferation assay. RESULTS: The water extract of dong quai dose-dependently and significantly stimulated the proliferation of MCF-7 cells with a weak estrogen-agonistic activity in the presence of 17beta-estradiol, as evidenced by the significant suppression by 4-hydroxytamoxifen. Meanwhile, the extract significantly exerted a growth-stimulating effect on BT-20 in a dose-dependent manner with or without 17beta-estradiol. No obvious difference was found in the growth of BT-20 cells treated with the extract in the presence of 17beta-estradiol or 4-hydroxytamoxifen. CONCLUSIONS: The water extract of dong quai stimulated the growth of MCF-7 cells, possibly dependent of weak estrogen-agonistic activity, and augmented the BT-20 cell proliferation independent of estrogen receptor-mediated pathway. The present study provides data regarding the estrogen-like activity of dong quai, which might assist in decision making on herbal therapy use by women at risk for both estrogen-sensitive and insensitive breast cancer. Because of the lack of clinical data demonstrating the potential side effects of dong quai, its use in herbal preparations for the treatment of peri- or postmenopausal symptoms, especially in women with breast cancer, warrants caution pending further study.