Inhibitory effect of gemcitabine and brucine on MDA MB-231human breast cancer cells

Combination of natural compounds and cytotoxic drugs represents a logical therapeutic approach for breast cancer. Brucine, a natural plant alkaloid is reported to possess cytotoxic, anti-inflammatory and anti-cancer activities. Gemcitabine is a nucleoside analog, commonly used in the treatment of several solid tumors, including breast cancer. In the present study we have examined the anticancer effect of brucine and gemcitabine on MDA MB-231 human breast cancer cells. Cell proliferation was assessed using MTT assay. Soft agar assay was used to evaluate the in-vitro clonogencity of MDA MB-231 cells. Cell migration was determined by in-vitro scratch assay and expression of p65 (NF-kB subunit) was evaluated by western blot analysis. Combination treatment with brucine and gemcitabine resulted in a significant inhibition of cell proliferation than either brucine or gemcitabine alone. Cells treated with combination of brucine and gemcitabine showed additive inhibition in colony formation and cell migration than treated with individual agents. The cells treated with brucine at 300 µM showed a significant decrease in p65-NF-kB expression but in combination treatment there was no additive inhibition of p65 expression compared to brucine treated cells. Overall, our results suggested that brucine in combination with gemcitabine showed supra-additive anticancer effects in MDA MB-231 cells and warrants further in-vivo studies in experimental animal models.