Ambrosin exerts strong anticancer effects on human breast cancer cells via activation of caspase and inhibition of the Wnt/β-catenin pathway

Purpose: To investigate the antitumor effects of ambrosin sesquiterpene lactone on drug-resistant MDA-MB-231 breast cancer cells. Methods: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used for cell viability studies. Apoptotic effects were determined using 4′,6-diamidino2-phenylindole (DAPI) staining assay, while Annexin V/PI was used for the quantification of apoptosis. Levels of reactive oxygen species (ROS) were determined by flow cytometry using DCFH-DA fluorescence staining while the effects of ambrosin on apoptosis and Wnt/beta-catenin signaling pathway-allied proteins were evaluated by Western blotting assay. Results: Ambrosin significantly suppressed the viability of MDA-MB-231 cells in a dose- and time-dependent manner (p < 0.05). Results from Annexin V/PI staining revealed that ambrosin induced production of apoptotic crops and blebbing of plasma membrane in MDA-MB-231 cells. Furthermore, annexin V/PI assay results showed increases in percentage of cells in different stages of apoptosis. Thus, ambrosin promoted caspase-dependent-apoptosis in MDA-MB-231 cells. Moreover, ambrosin enhanced the formation of ROS in MDA-MB-231 cells, as was evident from increased DCF- fluorescence (p < 0.05). The results also showed dose-dependent inhibition of Wnt/beta-Catenin signaling pathway by ambrosin. Conclusion: Ambrosin exerts a chemo-preventive effect on breast cancer cells via induction of programmed cell death, enhanced ROS production, caspase activation and suppression of Wnt/beta- catenin signaling. These findings have potential benefits for breast cancer research and drug discovery