The effects of curcumin post-treatment against myocardial ischemia and reperfusion by activation of the JAK2/STAT3 signaling pathway.

In this study, we evaluated the effect of curcumin (Cur) post-treatment on isolated perfused rat hearts that had been subjected to a protocol of ischemia and reperfusion injury. We also examined whether the Janus kinase 2 and signal transducer and activator 3 of transcription (JAK2/STAT3) signaling pathway plays a role in the cardioprotective effects of Cur post-treatment. Isolated perfused rat hearts were subjected to 60 min of ischemia, followed by 60 min of reperfusion. The hearts were exposed to 1-μM Cur during the first 10 min of reperfusion in the absence or presence of the JAK kinase-specific inhibitor AG490 (AG, 1 μM). The Cur treatment conferred a cardioprotective effect, and the treated hearts demonstrated an improved post-ischemic cardiac functional recovery, a decreased myocardial infarct size and decreased lactate dehydrogenase release in the coronary flow, a reduced number of apoptotic cardiomyocytes, up-regulation of the anti-apoptotic protein Bcl2 and down-regulation of the pro-apoptotic protein Caspase3. AG blocked the Cur-mediated cardioprotection by inhibiting the JAK2/STAT3 signaling pathway, as reflected by the abrogation of the Cur-induced up-regulation of Bcl2 and down-regulation of Caspase3. The results suggest that Cur post-treatment can attenuate IR injury through the activation of the JAK2/STAT3 signaling pathway, which transmits a survival signal to the myocardium.