Abstract: Objective: To investigate the effect of taraxerol on the proliferation and apoptosis of breast cancer MCF-7 cells and to explore its possible mechanism of action. Methods: The effect of taraxerol on the proliferation of MCF-7 cells was detected by methylthiazolyldiphenyltetrazolium bromide assay and colony formation assay; cell apoptosis was tested by Hoechst 33342 fluorescence staining, and apoptosis-related protein expression was detected by Western blot. Results: Taraxerol significantly inhibited the proliferation of MCF-7 cells (P < 0.05). Hoechst staining revealed a series of morphological changes in MCF-7 cells associated with apoptosis, and Western blot data indicated that taraxerol significantly increased the ratio of Bax/Bcl-2 (P < 0.01) and up-regulated cleaved caspase-3/9 expression (P < 0.01), and down-regulated PARP expression (P < 0.01). Conclusion: Taraxerol can inhibit the proliferation, and induce the apoptosis of MCF-7 cells via the mitochondrial signaling pathway.

Key words: breast cancer, taraxerol, apoptosis, mitochondrial pathway