Radiation therapy is commonly applied in breast cancer (BC) patients. However, radioresistance and side effects are limiting factors of this practice. Therefore, studying substances that can enhance the radiation effect and, at the same time, protect normal cells is very relevant. Thus, the aim of this work was to assess the radiosensitizer effect of resveratrol (RV) on BC cells (MCF-7). A high cytotoxic and antiproliferative effect was observed in the treatment with 10 μM of RV + 3 Gy ionizing radiation (IR). Our results indicate that, 24 h after the exposition of cell cultures to RV + IR, an induction of necrosis/senescence has occurred. Furthermore, was observed the activation of extrinsic apoptosis pathway through a decrease of the Bax/Bcl-2 ratio and a high activity of caspase 8. Moreover, our data show that this treatment affected the oxidative cell metabolism, increasing oxidative protein, lipid and membrane damage and also acted to decrease the antioxidant enzymes activity. The antiproliferative effect on 72 h cultures may be associated with a high expression of p53 and an interruption of cell cycle in the S phase. Therefore, our results suggest that RV is a potential radiosensitizer of MCF-7 BC cells.

放射治疗通常用于乳腺癌（BC）患者。但是，抗辐射性和副作用是这种做法的限制因素。因此，研究可以增强辐射作用并同时保护正常细胞的物质非常重要。因此，这项工作的目的是评估白藜芦醇（RV）对BC细胞（MCF-7）的放射增敏作用。在10μMRV + 3 Gy电离辐射（IR）的治疗中，观察到了很高的细胞毒性和抗增殖作用。我们的结果表明，在将细胞培养物暴露于RV + IR后24小时，已经发生了坏死/衰老的诱导。此外，还观察到通过降低Bax / Bcl-2比和激活caspase 8的活性来激活外在凋亡途径。我们的数据表明，这种处理影响了氧化细胞的代谢，增加了氧化蛋白，脂质和膜的损伤，还降低了抗氧化酶的活性。对72 h培养物的抗增殖作用可能与p53的高表达和S期细胞周期的中断有关。因此，我们的结果表明RV是MCF-7 BC细胞的潜在放射增敏剂。