Objective To investigate the protective effects and underlying molecular mechanisms of p-coumaric acid (p-CA) against acute myocardial ischemia (AMI) through inhibition of inflammatory signaling. Methods Common targets of p-CA and AMI were predicted and screened using databases such as PubChem. These common targets were imported into the STRING database to construct a protein-protein interaction (PPI) network, followed by topological analysis. Gene ontology (GO) function and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were performed using DAVID database and bioinformatics platform. The binding affinity and stability between p-CA and myeloid differentiation 2 (MD2), a co-receptor of Toll-like receptor 4 (TLR4), were analyzed using molecular docking and molecular dynamics simulations. An AMI mouse model was established by ligating the left anterior descending coronary artery. The mice were randomly assigned into sham group, model group, p-CA (100 mg/kg) group, carvedilol (7.6 mg/kg) group and TAK-242 (3 mg/kg) group. After seven consecutive days of treatment, echocardiography was performed to evaluate cardiac function. Myocardial histopathological damage was observed using hematoxylin-eosin (HE) and Masson staining. Activity of creatine kinase-MB, level of cardiac troponin I (cTnI) in serum and levels of inflammatory factors in myocardial tissue were detected. The expressions of proteins related to TLR4/nuclear factor-κB (NF-κB) inflammatory pathway in myocardial tissue were measured by Western blotting. A hypoxia-inflammatory complex injury model in H9c2 cardiomyocytes was constructed to further evaluate the regulatory mechanism of p-CA on TLR4/NF-κB inflammatory signaling pathway. Results Network pharmacology analysis indicated that p-CA could act on core targets such as TLR4 and regulate TLR and NF-κB pathways to treat AMI. Molecular docking results demonstrated that p-CA exhibited favorable binding affinity with MD2, a co-receptor of TLR4. Molecular dynamics simulations further verified that the p-CA-MD2 complex possessed good structural stability. The results of animal experiments showed that p-CA significantly improved cardiac function in AMI mice (P < 0.01, 0.001), alleviated inflammatory cell infiltration in myocardial tissue, inhibited collagen deposition and myocardial fibrosis, and reduced activity of CK-MB and level of cTnI in serum (P < 0.01, 0.001). Furthermore, p-CA downregulated TLR4, p-NF-κB/NF-κB, NOD-like receptor thermal protein domain associated protein 3 (NLRP3), gasdermin D (GSDMD), interleukin-1β (IL-1β) protein expressions and IL-6 level in myocardial tissue (P < 0.05, 0.01, 0.001). The results of cell experiments confirmed that p-CA significantly suppressed the protein expression levels of TLR4, p-NF-κB/NF-κB and NLRP3 (P < 0.05, 0.01). Conclusion p-CA could improve cardiac function in AMI, inhibit myocardial inflammatory response and fibrosis, and its mechanism is associated with the regulation of TLR4/NF-κB inflammatory pathway.

p-coumaric acid  /  myocardial ischemia  /  network pharmacology  /  molecular docking  /  molecular dynamics simulation  /  TLR4  /  NF-κB