Abstract
BACKGROUND: Myocardial ischemia-reperfusion injury (MIRI) remains a therapeutic challenge with limited treatment options. Ferroptosis, characterized by lipid peroxidation, contributes significantly to MIRI pathogenesis. This study investigates whether dihydromyricetin (DHM), a bioactive flavonoid from Ampelopsis grossedentata, alleviates MIRI by inhibiting ferroptosis, and explores its cardioprotective mechanisms. METHODS: A mouse myocardial I/R model was established in vivo by ligating the left anterior descending coronary artery for 30 min, followed by reperfusion for one or 7 days. Mice were pretreated with DHM (125 or 250 mg/kg, gavage) for 4 weeks, or with Fer-1 (10 mg/kg) for 1 week. In vitro, an OGD/R model was constructed using H9c2 cells, which were then treated with DHM (0-200 μM) or Fer-1 (10 μM). Potential targets were screened via network pharmacology. Target interaction was validated through biotin-pull-down, molecular docking, CETSA, and DARTS assays. Functional validation was performed using PPARα-knockdown and rescue cell lines. RESULTS: GSEA indicated significant activation of the ferroptosis pathway in MIRI, and cellular experiments confirmed that OGD/R induced a typical ferroptosis phenotype. DHM dose-dependently reversed OGD/R-induced ferroptosis-related alterations and ameliorated mitochondrial ultrastructural damage. In vivo, DHM pretreatment significantly reduced serum CK-MB levels, myocardial infarct size, and histopathological injury in I/R mice, while reversing cardiac ferroptosis marker changes. Mechanistically, network pharmacology identified seven overlapping targets, among which DHM specifically reversed the downregulation of PPARα. Biochemical assays and molecular docking confirmed that DHM directly binds to and stabilizes PPARα via the E286 site. Knockdown of PPARα markedly attenuated the anti-ferroptotic and cardioprotective effects of DHM, whereas PPARα rescue partially restored its function. CONCLUSION: This study demonstrates for the first time that DHM alleviates ischemia-reperfusion injury by directly targeting the E286 site of PPARα, upregulating its levels, and thereby suppressing cardiomyocyte ferroptosis. This finding reveals a novel mechanism underlying the cardioprotective effect of DHM and provides a new theoretical basis for targeting the PPARα-ferroptosis axis in MIRI intervention.