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 μg/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 μg/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.