Chrysin restores the cardioprotective effect of ischemic preconditioning in diabetes-challenged rat heart

Background: Ischemic preconditioning (IPC) is the utmost capable design to achieve protection over ischemia-reperfusion injury (I/R), but this phenomenon gets attenuated during various pathological conditions like diabetes. Chrysin exhibits cardioprotection in various experiments however, its therapeutic potential on IPC-mediated cardioprotection via PI3K-Akt-eNOS pathway in streptozotocin (STZ) triggered diabetes-challenged rat heart is yet to be assessed. For that reason, the experiment has been planned to investigate chrysin's effect on the cardioprotective action of IPC involving the PI3K-Akt-eNOS cascade in rat hearts challenged to diabetes. Methods: The project was accomplished through means of absorbance studies for biochemical parameters, infarct size measurement (TTC stain) and coronary flow. Results: The findings of the present study revealed that STZ drastically augmented the serum glucose level and the chrysin significantly reversed the IPC-stimulated increased coronary flow, nitrite release, and reduced LDH (lactate dehydrogenase), CK-MB (creatine kinase) activities as well as infarct size in diabetes-induced rat heart. Furthermore, chrysin also reversed the IPC-induced reduction in oxidative stress in an isolated Langendorff's perfused diabetic rat heart. Moreover, four episodes of preconditioning by either PI3K or eNOS inhibitor in chrysin-pretreated diabetic rat hearts significantly abolished the protective effect of chrysin. Conclusion: Consequently, these observations suggested that chrysin increases the therapeutic efficiency of IPC in mitigating I/R injury via PI3K-Akt-eNOS signalling in diabetes-challenged rat hearts. Hence, chrysin could be a potential alternative option to IPC in diabetic rat hearts.