Apoptotic Effect of Koumine on Human Breast Cancer Cells and the Mechanism Involved.

Koumine is an alkaloid separated from traditional Chinese herb Gelsemium elegans. In this study, anticancer activity and underlying mechanisms were investigated with an extract using human breast cancer cells. The survival rate was reduced in a concentration- and time-dependent manner as assessed by MTT assay. After incubation for 48 h, typical apoptotic morphological changes were observed by Hoechst 33258 dye assay. Flow cytometry result revealed that the treatment obviously induced G2/M arrest and apoptosis in MCF-7 cells. Furthermore, Western blotting demonstrated the down-regulation of protein expression of Bcl-2, whereas Bax and caspase-3 expressions were up-regulated. Therefore, we propose that koumine has the potential to be a future breast cancer chemotherapeutic agent.