curcumin-etoposide synergy: unveiling the molecular mechanisms of enhanced apoptosis and chemoresistance attenuation in breast cancer

Background: combining natural compounds with chemotherapeutic agents has emerged as a promising approach for cancer treatment. curcumin (cur), a natural polyphenol, is known for its anti-cancer properties, including the ability to induce apoptosis and arrest cell cycle progression.objectives: this study aimed to evaluate the effects of cur and etoposide (eto), both individually and in combination, on the induction of apoptosis in breast cancer (bc) cell lines.methods: the impact of cur and eto on cell proliferation was assessed using mtt viability assays. apoptosis induction by these drugs was evaluated through annexin v flow cytometry and caspase-3 and caspase-9 activity assays. quantitative real-time pcr was employed to measure bax and bcl-2 gene expression levels. western blotting was conducted to determine protein levels of p53, p21, bax, and bcl-2.results: a non-significant dose of eto was selected based on mtt assay results and combined with 75 µm of cur. curcumin enhanced eto’s pro-apoptotic effect by increasing caspase activities. the combination of cur and eto significantly reduced bcl-2 gene expression while upregulating bax expression. furthermore, treatment with this combination elevated the protein levels of p53, p21, and bax, compared to eto or cur alone, while significantly decreasing bcl-2 protein levels.conclusions: cur has the potential to amplify eto-induced apoptosis in bc cells. this combination may offer a promising therapeutic approach for bc.