Cardioprotective effect of protocatechuic acid on myocardial ischemia/reperfusion injury.

Protocatechuic acid (PCA), a phenolic compound and one of the main metabolites of complex polyphenols, has been found to possess various biological activities, and it may have a potential in the treatment of ischemic heart diseases. This study explored the cardioprotective effect of PCA on myocardial ischemia/reperfusion (MI/R) injury and the underlying mechanisms. In an in vivo rat model of MI/R injury, myocardial infarct size, serum TNF-a level, and platelet aggregation were measured. In a primary neonatal rat cardiomyocyte model of hypoxia/ reoxygenation (H/R) injury, the apoptotic rate, expressions of cleaved caspase-3, and phosphorylated Akt were observed. We found that PCA significantly reduced myocardial infarct size, serum TNF-a level, and platelet aggregation. In vitro experiments revealed that PCA significantly inhibited the apoptotic rate and the expression of cleaved caspase-3, and it upregulated the expression of phosphorylated Akt in cardiomyocytes subjected to H/R injury. Our results suggest that PCA can provide a significant protection against MI/R injury, which may be at least partially attributed to its inhibitions against injury induced by MI/R including the inflammatory response, platelet aggregation, and cardiomyocytes apoptosis.