Circulating inflammatory and oxidative stress biomarker responses to apigenin pretreatment following whole-body X-ray irradiation in rats.

PURPOSE: Whole-body ionizing radiation induces inflammatory and oxidative stress responses. This study evaluated radiation-induced changes in serum high mobility group box 1 (HMGB1), myeloperoxidase (MPO), and malondialdehyde (MDA) and examined the effects of apigenin (Api) pretreatment on these biomarkers. MATERIALS AND METHODS: Forty-eight male Wistar rats were randomly allocated to 12 groups (n = 4). Api (10 or 20 mg/kg) was administered intraperitoneally once daily for 7 days, with the final dose given 1 h before 6 Gy whole-body X-ray irradiation. Serum HMGB1, MPO, and MDA levels were measured at 6 and 72 h after irradiation. Body weight was monitored for 72 h. RESULTS: Irradiation increased HMGB1 to 1.28- and 1.17-fold at 6 and 72 h, respectively, and MDA to 3.20- and 4.64-fold versus control. Api reduced HMGB1 to 0.78-0.79-fold at 6 h and 0.81-0.85-fold at 72 h versus irradiation. MDA decreased to 0.73-fold with Api 10 mg/kg at 6 h and to 0.38-0.34-fold with both doses at 72 h. MPO remained unchanged. Api also attenuated weight loss at 72 h (all significant comparisons p < .05). Body weight remained higher than irradiation alone. CONCLUSION: Whole-body X-ray irradiation increased circulating HMGB1 and MDA levels and reduced body weight, whereas MPO remained unchanged. Api pretreatment lowered HMGB1 and MDA levels and attenuated body weight loss. As survival, functional outcomes, and NET formation were not assessed, these findings should not be interpreted as evidence of radioprotection or modulation of NETosis.