Abstract: Objective To determine the protective effect of berberine (BBR) on myocardial ischemia/reperfusion (MI/R) injury in rats and the role of JAK2/STAT3 signaling pathway in this process. Methods Male Sprague-Dawley rats were randomly divided into 7 groups (n=36): Sham, Sham+BBR, Sham+AG (AG490, the inhibiter of JAK2/STAT3 signaling pathway), MI/R+V (vehicle), MI/R+BBR, Sham+BBR+AG and MI/R+AG, and then exposed to MI/R insult. After 4 h of reperfusion, myocardial p-JAK2/JAK2 and p-STAT3/STAT3 ratios, and the apoptotic related protein expressions were assessed. After 6 h of reperfusion, myocardial apoptotic index and infarct size were evaluated. The cardiac function were measured after72 h of reperfusion. Results BBR treatment significantly improved cardiac functional and reduced cardiomyocytes apoptosis. In addition, BBR treatment also activated JAK2/STAT3 signaling and suppressed apoptotic signaling. However, these protective effects were all inhibited by AG treatment. Conclusion The present experiment showed that BBR attenuated MI/R injury by reducing apoptosis possibly via activating JAK2/STAT3 signaling pathway.

Key words: Berberine, JAK2/STAT3 signaling pathway, myocardial ischemia/reperfusion injury, apoptosis, cardioprotection