Abstract
Prevention and management of myocardial ischemia/reperfusion (I/R) injury is a key step in coronary heart disease surgery. Luteolin is a falconoid compound that has an antioxidant effect, but its mechanism in I/R injury in vivo and in vitro is still under explored. This study attempted to reveal the role of luteolin (Lut) in I/R through mediation of the Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1)/Signal transducer and activator of transcription 3 (STAT3) pathway. To establish I/R rat models, the left anterior descending artery (LAD) was ligated for 30 min and re-perfused for 1 h in Lut-pretreated or nude rats. Comparisons between infarct area, cardiac dysfunction, and myocardial cell death and inflammatory reaction were performed in I/R-induced rats. Hypoxia/reoxygenation (H/R) cell models were established by stimulating H9c2 cells with 95% nitrogen and 5% carbon dioxide. Simultaneously, H/R-related cell death and inflammatory reactions were investigated following Lut treatment. The target protein of Lut was identified using western blotting. Pro-inflammatory cytokines were also measured in serum or Lut-pretreated cell culture medium. The results revealed that compared with the I/R group, Lut treatment could significantly decrease myocardial infarction (MI) area, increase left ventricular ejection fraction (LVEF), and decrease cell death and pro-inflammatory cytokines in the serum. Decreased apoptosis and inflammatory cytokines were also observed in H/R cells after Lut treatment. Lut treatment downregulated SHP-1 expression and subsequently upregulated STAT3 phosphorylation in both I/R rat heart tissue and H9c2 cells. The findings of the current study suggest that Lut can protect the heart and reduce MI area, cell apoptosis rate, and inflammatory level in I/R models.