Prunetin ameliorates myocardial pyroptosis after myocardial infarction by inhibiting the TNF-α/p38 MAPK/ERK pathway

Background: The inflammatory response in cardiac tissue after myocardial infarction (MI) plays a critical role in myocardial injury. Prunetin (PRU), a natural flavonoid compound, has notable anti-inflammatory properties; however, its role in post-MI myocardial injury and the underlying molecular mechanisms remain unclear. Methods: Network pharmacology was used to predict potential targets of PRU in MI, identifying TNF-α as a high-affinity target. This interaction was further validated by molecular dynamics (MD) simulation and surface plasmon resonance (SPR) assays. A mouse MI model was established to evaluate the protective effects of PRU using echocardiography, histological staining, and serological assays. RNA sequencing was performed to explore the underlying mechanisms, and Western blotting and immunofluorescence were used to assess the TNF-α/p38 MAPK/ERK signaling pathway and pyroptosis-related proteins. R848, a TLR7/8 agonist, was used to induce TNF-α expression and evaluate whether TNF-α activation could reverse the protective effects of PRU. Results: experiments showed that PRU significantly improved cardiac function in MI mice, reduced serum levels of myocardial injury markers, attenuated myocardial fibrosis, and decreased inflammatory cytokine release. PRU also markedly downregulated pyroptosis-related proteins, including NLRP3 and GSDMD-N. Mechanistically, PRU inhibited MI-induced activation of the TNF-α/p38 MAPK/ERK signaling pathway, thereby suppressing cardiomyocyte pyroptosis. R848 reversed the cardioprotective effects of PRU. These findings were further validated in models of damage to cardiac organoids and cardiomyocytes induced by glucose-oxygen deprivation (OGD). Notably, the data on PRU's protective effects in human cardiac organoid models were highly consistent with observations in mice, further reinforcing the clinical relevance and translational potential of this mechanistic hypothesis. Conclusions: PRU attenuates post-MI myocardial injury by inhibiting TNF-α/p38 MAPK/ERK signaling, thereby reducing cardiomyocyte pyroptosis and inflammatory responses. These findings provide a theoretical basis for the potential development of PRU as a therapeutic candidate for post-MI myocardial injury.