Baicalin alleviates X-ray radiation-induced intestinal injury by inhibiting GPX4 mediated ferroptosis

Radiation-induced intestinal injury (RIII) is a common complication of radiotherapy for abdominal and pelvic malignancies, for which effective therapeutic options remain limited. Baicalin, a flavonoid derived from Scutellaria baicalensis, exhibits anti-inflammatory and antioxidant properties, but its role in RIII and underlying mechanisms remain unclear. C57BL/6J mice were exposed to total body irradiation (8.5 Gy) and treated with baicalin (25, 50, or 100 mg/kg/d) for 10 consecutive days. Intestinal injury was evaluated by histology, colon length, tight junction protein expression, and inflammatory cytokine levels. Ferroptosis was assessed by measuring glutathione peroxidase 4 (GPX4) expression and oxidative stress markers (MDA, GSH/GSSG). Human NCM460 colon epithelial cells were exposed to 10 Gy irradiation with or without baicalin (20 µM) to evaluate cell viability, invasion, apoptosis, GPX4 expression, Fe²⁺ accumulation, and reactive oxygen species (ROS) production. Baicalin treatment dose-dependently improved survival, increased food intake, attenuated body weight loss, and restored fecal output in irradiated mice. Baicalin alleviated intestinal histopathological damage, preserved colon length, restored ZO-1 and occludin expression, and suppressed IL-1β, IL-18, and TNF-α release. Notably, baicalin ameliorated radiation-induced mitochondrial damage, upregulated GPX4 expression, reduced MDA and GSSG levels, and restored GSH levels. In vitro, baicalin enhanced cell viability and proliferation, restored invasion capacity, and reduced apoptosis in irradiated NCM460 cells. Mechanistically, baicalin upregulated GPX4 expression and suppressed radiation-induced Fe²⁺ accumulation and ROS generation without affecting acyl-CoA synthetase long-chain family member 4 (ACSL4) expression. Baicalin protects against radiation-induced intestinal injury by inhibiting GPX4-mediated ferroptosis, suggesting its potential as a therapeutic agent for RIII.