Naringenin Enhances the Anti-Cancer Effect of Cyclophosphamide against MDA-MB-231 Breast Cancer Cells Via Targeting the STAT3 Signaling Pathway

Naringenin is a natural compound with potential anti-cancer effects against several cancer types.  Also, its precise molecular mechanisms regarding tumor growth suppression has not been completely elucidated. In the current study the apoptosis-inducing and anti-proliferative effects of Naringenin together with cyclophosphamide were studied in breast cancer cells and the participation of JAK2/STAT3 pathway was investigated. In this regard, MDA-MB-231 breast cancer cells were cultured and hence, treated with different concentrations of Naringenin. Apoptosis was measured via flowcytometric analysis of annexin V binding and cell viability was assessed via MTT assay. Protein and gene expression were investigated via Western blotting and real-time PCR, respectively. The function of caspase enzymes were also assessed. The results exhibited that Naringenin triggered apoptosis and markedly decreased cell viability. Furthermore its coadministration with cyclophosphamide improved its anti-tumor properties. Moreover, Naringenin up-regulated the expression of BAX while decreased the expression of Bcl-2. Caspases 3 and 9 were activated by Naringenin, an influence, which was augmented via cyclophosphamide. Docking studies revealed an interaction between Naringenin and STAT3 that was confirmed via attenuation of STAT3 phosphorylation subsequent to treating the cells with Naringenin. Furthermore, Naringenin exhibited the capacity to suppress the function of IL-6 in modulating apoptosis-associated genes expression. Overall, these results indicated that a Naringenin- cyclophosphamide combination impairs proliferation signaling and induces apoptosis to a greater extent than either compound alone and can serve as a potent chemotherapeutic regimen for breast cancer treatment.