Potential suppressive effects of gentian violet on human breast cancer MDA-MB-231 cells in vitro: Comparison with gemcitabine.

Gentian violet (GV), a cationic triphenylmethane dye, is used as an antifungal and antibacterial agent. Recently, attention has been focused on GV as a potential chemotherapeutic and antiangiogenic agent. The present study was undertaken to determine the suppressive effects of GV on human breast cancer MDA-MB-231 cells in vitro. The proliferation of MDA-MB-231 cells was suppressed by culture with GV (1-200 nM). The suppressive effects of GV on cell proliferation were not potentiated in the presence of various inhibitors that induce cell cycle arrest in vitro. This finding suggested that GV inhibits G1 and G2/M phase cell cycle arrest in MDA-MB-231 cells. The suppressive effects of GV on proliferation are mediated through the inhibition of various signaling pathways or nuclear transcription in vitro. Moreover, the suppressive effects of GV on cell proliferation were compared with that of gemcitabine, a strong antitumor agent that induces nuclear DNA damage. Notably, the culture with gemcitabine >50 nM suppressed cell proliferation, while the effects of GV were observed at >1 nM. The suppressive effects of gemcitabine on cell proliferation were not potentiated by GV. Overall, the present study demonstrated that GV exhibits a potential suppressive effect on the proliferation of human breast cancer MDA-MB-231 cells in vitro.