Theogallin Protects Myocardial Ischemia-Reperfusion Injury by Inhibiting the Interleukin-17 Signaling Pathway.

Tea polyphenols have been shown to prevent cardiovascular disease through antioxidant and anti-inflammatory mechanisms. Theogallin, a phenolic acid derived from gallic and quinic acids, is a unique polyphenolic compound found in teas. Its preventive effect on myocardial ischemia-reperfusion (I/R) injury remains unclear. This study utilized an ex vivo model of I/R injury in isolated rat hearts through Langendorff perfusion and an in vivo myocardial injury model through left anterior descending coronary artery (LAD) ligation. In isolated hearts, theogallin pretreatment at both 100 and 200 ng/mL significantly improved hemodynamic parameters following I/R injury. Additionally, in vivo, pretreatment with 20 mg/kg theogallin in LAD ligation rats for 7 days significantly enhanced myocardial contractile function, reduced the release of myocardial enzymes, and decreased infarct size and fibrosis in LAD ligation rats. These protective effects may be attributed to theogallin's ability to inhibit the expression of interleukin-17 (IL-17) receptor A, transcription factor Jun-B (JUNB), Fos-related antigen 1 (FRA1), and matrix metalloproteinase 9 (MMP9) in the IL-17 signaling pathway. These findings suggest that theogallin exerts cardioprotective effects by downregulating the IL-17 signaling pathway in rats with myocardial I/R injury.