Cinnamaldehyde mitigates acute myocardial infarction by regulating ferroptosis through the PI3K-AKT signaling pathway.

Objective: This investigation sought to elucidate the protective efficacy of Cinnamaldehyde (CA) against acute myocardial infarction (AMI) while investigating its therapeutic mechanisms through the integration of network pharmacology technology as well as in vitro and in vivo experiments.

Methods: An AMI rat model was constructed via left anterior descending coronary artery ligation after the experimental rats were subjected to continuous intragastric administration of CA over a 14-day period. In parallel, an AMI cell model was established by subjecting neonatal primary rat cardiomyocytes to glucose/oxygen deprivation (OGD). Network pharmacology was employed to predict CA's targets in AMI, and the CA-AMI target relationship network was constructed using the String database. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was conducted on CA-AMI targets to obtain significantly correlated signaling pathways. Molecular docking was performed to analyze the binding activity between CA and core targets. Rat cardiomyocytes underwent a 24-hour pretreatment with CA, followed by 1-hour exposure to the ferroptosis activator Erastin or the PI3K inhibitor Wortmannin. Myocardial infarction in rats was observed through triphenyl tetrazolium chloride staining, and the infarction size was subsequently calculated. Myocardial injury was assessed using hematoxylin-eosin staining. The quantification of interleukin (IL-6), tumor necrosis factor (TNF)-α, IL-1β, creatine kinase isoenzyme MB, lactate dehydrogenase, and cardiac troponin I was accomplished through enzyme-linked immunosorbent assay. A biochemical kit was used to quantify the levels of Fe, glutathione, malondialdehyde, and superoxide dismutase. The levels of reactive oxygen species were detected via performing dihydroethidium staining. Cell activity was determined through cell counting kit-8 assay, apoptosis was quantified via flow cytometry, and the expression levels of PI3K, AKT1, Caspase-3, GPX4, FTH1, and PTGS2 proteins were evaluated by Western blot.

Results: Pre-treatment with CA significantly reduced myocardial tissue damage and OGD-induced cardiomyocytes damage in AMI rats. A total of 77 CA-AMI targets were predicted through Network pharmacology. GO enrichment analysis revealed the primary involvement of CA-AMI targets in biological processes including apoptosis, inflammation, and oxidative stress. KEGG enrichment analysis revealed 155 related pathways, with a significant enrichment observed in the PI3K-AKT signaling pathway, closely linked to AMI. Western blot demonstrated that CA significantly activated the PI3K-AKT signaling pathway in cardiomyocytes and concurrently inhibited ferroptosis. In OGD-induced cardiomyocytes, intervention with Erastin diminished the protective effect of CA on cardiomyocytes, while Wortmannin intervention attenuated CA's inhibitory effect on cardiomyocyte ferroptosis.

Conclusion: CA demonstrates a significant ameliorative effect on AMI in rats, with its underlying mechanism seemingly revolving around the regulation of ferroptosis via activation of the PI3K-AKT signaling pathway.