Sodium butyrate promotes apoptosis in breast cancer cells through reactive oxygen species (ROS) formation and mitochondrial impairment

Background: Sodium butyrate (NaBu) is a short-chain fatty acid which serves as a histon deacetylase inhibitor and has received considerable interest as a possible regulator of cancer cell death. The regulatory effect of NaBu on cancer cell growth or death has yet to be illustrated in many cancers including breast cancer. This study is aimed to elucidate the possible effect of NaBu on regulation of breast cancer growth and apoptosis. Methods: The cytotoxic effect of NaBu on the growth of breast cancer cells (MCF-7 and MDA-MB-468) and normal breast cells (MCF-10A) was determined using MTT assay. Annexin-V-FITC staining and PI staining were performed to detect apoptosis and cell cycle distribution using Flow cytometry, the level of mitochondrial membrane potential (Delta psi m), Reactive oxygen species (ROS) formation and caspase activity were determined accordingly. Results: Based on our data, NaBu induced a dose and time-dependent cell toxicity in breast cancer cells which was related to the cell cycle arrest and induction of apoptosis. The impact of NaBu on MCF-10A cell toxicity, cell cycle distribution and apoptosis was inconsiderable. NaBu-elicited apoptosis was accompanied by the elevated level of ROS, increased caspase activity and reduced mitochondrial membrane potential (Delta psi m) in MCF-7 and MDA-MB-468 cells and with no effect on the above mentioned factors in MCF-10A cells. Conclusions: Our study provided insight in to the role of NaBu on the regulation of breast cancer cell growth and lighten up the pro-apoptotic activity of NaBu.