Mechanism of cytotoxicity by Psoralea corylifolia extract in human breast carcinoma cells.

Psoralea corylifolia has been widely used in herbal medicine, and a few studies show its anticancer activity. However, the detailed mechanism of the anticancer activity of P. corylifolia seed extract (PC extract) was not studied. This study evaluates the anticancer activity and underlying mechanism of PC extract in a human breast cancer cell line (MCF7). PC extract caused a concentration-dependent decrease in the proliferation of MCF7 cells and an increase in apoptotic death as measured by annexin-V-FITC and TUNEL assays. Increased cleavage of poly(ADP-ribose) polymerase in cells treated with PC extract further confirmed the apoptotic mode of cell death. There was a decrease (~2-fold) of mitochondrial membrane potential in cells treated with PC extract. In cells treated with PC extract, an increase in intracellular reactive oxygen species (ROS) and a decrease in mitochondrial ROS was observed. A significant decrease in ATP (~1.8-fold) was observed in extract-treated cells. Moreover, MCF7 cells treated with extract showed cleavage of caspase-9 and caspase-7, upregulation of Bax, release of cytochrome-c, and loss of mitochondrial integrity. Taken together, these results suggest the involvement of the mitochondrial pathway in PC extract-induced apoptosis in MCF7 cells.