LAUSR

PURPOSE Intestinal injuries caused by ionizing radiation (IR) are a major complication of radiotherapy. Ferrostatin-1 (Fer-1), a ferroptosis inhibitor, exerts antioxidant and anti-inflammatory effects in several diseases. We investigated the influence of Fer-1 on IR-induced intestinal damage and explored the possible mechanisms of action. MATERIALS AND METHODS IEC-6 cells were administrated with Fer-1 (0.25, 0.5, 2.5, 5, and 25 µM) for 30 min and subsequently subjected to 9.0 Gy-irradiation. Flow cytometry, qPCR, and western blotting were used to detect changes in cell function and molecular expression. For in vivo experiments, Fer-1 (5, 10, and 20 mg/kg) was given intraperitoneally to C57BL/6 male mice at 1 h before and 24 h after 9.0 Gy total body irradiation (TBI) respectively. Three days after TBI, the small intestines were isolated for pathological analysis and molecular expression analysis. The diversity and composition of the gut microbiota were analyzed by 16S rRNA gene sequencing. RESULTS The in vitro results demonstrated that Fer-1 protected IEC-6 cells from IR injury by reducing the production of reactive oxygen species and inhibiting both ferroptosis and apoptosis. In vivo, Fer-1 treatment enhanced the survival rates of mice subjected to lethal doses of IR and restored intestinal structure and physiological function. Further investigation showed that Fer-1 protected IEC-6 cells and mice from IR by inhibiting the p53-mediated apoptosis signaling pathway and restoring the gut-microbe balance. CONCLUSION This study confirms that Fer-1 protects against IR-induced intestinal injuries through suppressing apoptosis and ferroptosis, and may serve as a potential radio protective drug against IR-induced intestinal injuries.