Effects of black cohosh (Cimicifuga racemosa) extract on apoptosis and proliferation rates in hmscs, mcf7, mda-mb-231 and lncap cells

Recently, herbal therapeutics such as Cimicifuga racemosa (L.) Nutt. (CR) has gained interest as an alternative to hormone replacement therapy. New findings, which additionally demonstrate osteoprotective effects of CR in ovariectomized rats, would make CR an optional herbal drug for osteoporosis prevention and treatment. Purified fractions of CR containing saponin (S) and aqueous (A) soluble contents were examined in vitro to determine their effects on cell viability and proliferation on a series of tumor cells and osteogenic precursors, respectively.

Human mesenchymal stem cells (hMSCs), estrogen receptor-positive (MCF7) and estrogen receptor-negative (MDA-MB-231) human breast adenocarcinoma cell lines as well as androgen-sensitive human prostate adenocarcinoma cells (LNCaP) (n=3) were stimulated with the whole CR extract, S and A fractions in a range of 0 up to 1000ng/ml. After 72h incubation, apoptosis (Caspase-Glo 3/7-Assay, Promega) and proliferation (CellTiterGlo-Luminescent Cell Viability Assay, Promega) rates were determined.

The apoptosis rate is decreased down to 33% compared to untreated cells in all investigated cells and cell lines. No noticeable effect regarding the proliferation rate of hMSCs, MCF7 and MDA-MB-231 cells was detected except for a border line stimulating effect on LNCaP cells. The overall toxicity of such extracts appeared to be very low, cell death occurred beyond concentrations of 1mg/ml.

The obtained data show inhibitory effects of CR extracts on apoptosis but no cytotoxicity as measured by proliferation assays in hMSCs, MCF7 and MDA-MB-231 cells. Hence, CR does not possess toxic effects at concentrations of up to 1000ng/ml extract upon the cells mentioned.