Quercetin Potentiates the Chemosensitivity of Human Breast Cancer Cells to 5-Fluorouracil

Abstract Background: breast cancer is one of the leading causes of cancer mortality worldwide. 5-fluorouracil (5-FU) is one of the chemotherapy drugs to treat breast cancer, but it is associated with several side effects. Combination therapy is a way to increase the effectiveness of chemo drugs and decrease their usage dose. Quercetin (Quer) is one of the natural polyphenols with anti-cancer properties. This study investigated the apoptotic effect of 5-FU in combination with Quer compared with 5-FU alone on MCF7 breast cancer cells.Method and Results: Different single and combined concentrations of 5-FU and Quer were applied to MCF 7 cells for 48 hours. Cell viability, apoptosis, gene expression of Bax and Bcl2, and colony number were assessed using MTT assay, flow cytometry, quantitative real-time PCR, and Colony formation assay, respectively. The combination of 5-FU and Quer compared to 5-FU alone improved apoptosis by increasing and decreasing the gene expression of Bax and Bcl2, respectively, and decreased colony formation in MCF7 cells.Conclusion: Quer potentiates the sensitivity of breast cancer to 5-FU so that this combination may be proposed as a treatment for breast cancer. Therefore, this combination can be suggested for future in vivo studies.