Inhibitory effect of an isopropanolic extract of black cohosh on the invasiveness of MDA-mB 231 human breast cancer cells.

BACKGROUND The isopropanolic extract of black cohosh (iCR)b has recently been reported to exert antiproliferative and apoptosis-inducing effects on estrogen receptor-positive MCF-7, as well as estrogen receptor-negative MDA-MB 231 human breast cancer cells. To broaden observations, the anti-invasive effects of iCR and its two major fractions triterpene glycosides (TTG) and cinnamic acid esters (CAE) were tested in highly invasive MDA-MB 231 cells. MATERIALS AND METHODS The effect of drugs upon the invasive potential of MDA-MB231 cells was studied in BD Biocoat Matrigel invasion chambers over a period of 24 h. RESULTS The suppression of invasion reached 51.8% at 77.4 microg/ml of iCR, an extract concentration where 89% of MDA-MB231 cells were viable. TTG and CAE reduced cell invasion by 34% and 25.5%, respectively, at a dose of 5 microg/ml. The motility of cells was only moderately reduced. CONCLUSION In this study iCR was found to suppress tumor cell invasion without affecting cell viability. This result together with the antiproliferative and apoptosis-inducing effect of iCR suggest its use as a secure agent in postmenopausal hormone replacement therapy with additional chemopreventive activity.