Breast cancer is the leading cause of female mortality worldwide. Although there are several modern treatments for breast cancer, there is a high rate of recurrence for the majority of treatments; therefore, the search for effective anticancer agents continues. The present study aimed to investigate the anti-breast cancer potential of frullanolide, a compound which is isolated and purified from the Grangea maderaspatana plant, for selected human breast cancer cell lines (MCF-7, MDA-MB-468 and MDA-MB-231). The MTT assay was used to assess cytotoxic activity in breast cancer cell lines of treatment with frullanolide at 1.25, 2.5, 5.0, 10.0 and 20.0 µg/ml. Additionally, the apoptotic induction ability of frullanolide at various concentrations [0.5×, 1× and 2× half maximal inhibitory concentration (IC50)] was investigated by flow cytometry and western blot analysis. Frullanolide exhibited strong anti-breast cancer activity against MDA-MB-468 (IC50, 8.04±2.69 µg/ml) and weak cytotoxicity against the MCF-7 (IC50, 10.74±0.86 µg/ml) and MDA-MB-231 (IC50, 12.36±0.31 µg/ml) cell lines. The IC50 of frullanolide was high in the human normal epithelial breast cell line (MCF-12A) and mouse fibroblast cell line (L-929). Density plot diagrams revealed that frullanolide induced apoptosis in MCF-7, MDA-MB-468 and MDA-MB-231 cells. Notably, a plausible anticancer mechanism was elucidated via cellular apoptosis by p53-independence in the treated MCF-7 cell line and p53-dependence in the treated MDA-MB-468 and MDA-MB-231 cell lines. In conclusion, the present study demonstrated that frullanolide may exert anticancer activity on breast cancer cell lines by inducing apoptosis. Frullanolide offers a possible novel approach to breast cancer therapy.
Keywords: apoptosis; breast cancer cell lines; frullanolide; natural compounds; sesquiterpene lactone.