Quercetin inhibits ferroptosis to alleviate intestinal ischemia-reperfusion injury

To investigate the role of quercetin (QUE) in ferroptosis during intestinal ischemia-reperfusion (IR) injury and elucidate its underlying mechanisms.

① Potential target genes of QUE were predicted using the TCMSP, PharmMapper, and SwissTargetPredictive databases. Target genes associated with intestinal IR injury and ferroptosis were collected from GeneCards, PharmGKB, and OMIM databases. After overlapping genes were identified and analyzed, protein-protein interaction (PPI) networks were constructed using the STRING database and then visualized with Cytoscape 3.10.0. Molecular docking was performed to validate the binding conformations between QUE and key targets. ② In vivo experiments were conducted to verify QUE’s protective effects against intestinal IR injury. Thirty-six SPF-grade male C57BL/6J mice (6~8 weeks old, body weight: 22±2 g) were randomly divided into Sham, Sham+QUE, IR, IR+QUE, IR+QUE+erastin (IR+QUE+Era), and IR+QUE+ kevetrin hydrochloride (IR+QUE+KH) groups, with 6 mice in each group. Mouse model of intestinal IR injury was induced by 45 min ischemia of the superior mesenteric artery followed by 60 min reperfusion. HE staining was used to observe histopathological changes in the intestinal tissues. ELISA was employed to the serum or intestinal contents of diamine oxidase (DAO), pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), and ferroptosis markers [glutathione (GSH) and Fe²⁺] Western blotting was utilized to detect the protein expression of glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4), and tumor protein 53 (p53).

① Network pharmacology identified 460 QUE targets, 1552 intestinal IR injury targets, and 1967 ferroptosis-related targets, and 92 overlapping genes were identified as potential therapeutic targets. Molecular docking revealed a strong binding affinity between QUE and p53 (binding energy:-6.8 kcal/mol). ② In vivo experiments demonstrated that the IR+QUE group exhibited reduced intestinal damage and lower Chiu’s score (P<0.05), decreased serum DAO content but elevated intestinal DAO content (P<0.05), decreased levels of TNF-α, IL-6, and IL-1β in the serum and intestinal tissues (P<0.05), reduced Fe²⁺ accumulation, and increased GSH content (P<0.05), and up-regulated GPX4 (P<0.05) and down-regulated ACSL4 and p53 expression (P<0.05) at protein level when compared with the IR group. While, the administration of ferroptosis agonist Era, or p53 agonist KH resulted in diminished therapeutic effects of QUE (P<0.05) when compared with the IR+QUE group.

QUE alleviates intestinal IR injury by inhibiting ferroptosis, which may be associated with its down-regulating p53 expression.