Quercetin and low-dose gamma irradiation modulate oxidative stress, inflammation, autophagy, and apoptosis in DEN-induced hepatocarcinogenesis

Abstract Background Diethylnitrosamine (DEN) induces hepatic injury and can promote hepatocarcinogenesis. Quercetin (QR) and low-dose gamma irradiation (LDR) have been explored as hepatoprotective and anticancer-modulating agents, but their combined effects in DEN-induced liver cancer have not been previously examined. Aim To, for the first time, evaluate the novel combination of QR with LDR and compare its efficacy to QR or LDR alone in modulating DEN-induced liver cancer. Methods Hepatic injury was induced in ninety male rats by intraperitoneal DEN administration (75 mg/kg weekly for 3 weeks, then 100 mg/kg weekly for 3 weeks). After 6 weeks, hepatic injury establishment was confirmed histopathologically in a subset of rats. Animals were then randomized into five groups for an 8-week treatment period: (C) normal control; (DEN) no further treatment; (DEN + QR) quercetin (50 mg/kg/day, oral); (DEN + IR) fractionated low-dose γ-irradiation (0.25 Gy once weekly for 4 weeks, total 1 Gy); (DEN + QR+IR) combined QR + IR. The total experimental duration was 14 weeks. Results DEN induced severe hepatotoxicity, with significantly elevated serum ALT and AST compared to controls ( p < 0.001). Markers of oxidative stress were markedly increased, while antioxidant enzymes and GSH were significantly reduced ( p < 0.001). DEN also led to substantial activation of inflammatory and growth signaling pathways, including NF-κB, STAT-3, mTOR, and p38 MAPK ( p < 0.001). Autophagy markers ULK-1, LC3-II, and ATG5 were significantly suppressed, and a pro-survival shift was evident with reduced caspase-3 activity and increased BCL-2 expression ( p < 0.001).Treatment with quercetin (DEN + QR) or low-dose γ-irradiation (DEN + IR) alone significantly mitigated these alterations versus DEN, restoring liver enzymes, reducing oxidative stress and inflammation, and promoting apoptotic signaling ( p < 0.001). The combination therapy (DEN + QR+IR) produced the most pronounced effects, with greater normalization of all biochemical and molecular parameters compared to DEN and to either monotherapy ( p < 0.001). These changes were statistically superior to those observed with quercetin or irradiation alone ( p < 0.01). Flow cytometry confirmed enhanced apoptosis and altered cell cycle dynamics in the combination group. Histopathological analysis showed markedly improved hepatic architecture and the lowest pathology scores with combination therapy ( p < 0.001 vs. DEN). Conclusion This study reveals, for the first time, a combined hepatoprotective effect of quercetin with low-dose gamma irradiation in DEN-induced liver pathology, suggesting new mechanistic insights and promising translational potential for combined therapy in DEN-associated liver injury and hepatocarcinogenesis. Clinical Trial This work isn’t a clinical Trial.