Effect of tyrosol on myocardial ischemia-reperfusion injury in diabetic rats and the role of SIRT1/ AMPK/eNOS signaling pathway / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of tyrosol on myocardial ischemia-reperfusion (I/R) injury in diabetic rats and the role of silent mating-type information regulation 1 (SIRT1)/adenosine monophosphate-activated protein kinase (AMPK)/endothelial nitric oxide synthase (eNOS) signaling pathway.Methods SPF healthy adult male Sprague-Dawley rats,weighing 200-220 g,were intraperitoneally injected with streptozotocin 60 mg/kg to establish the model of diabetes mellitus.Fifty-six diabetic rats were divided into 4 groups (n =14 each) using a random number table method:sham operation group (S group),myocardial I/R group (I/R group),myocardial I/R plus tyrosol group (I/R+T group),and myocardial I/R plus tyrosol plus SIRT1 inhibitor EX527 group (I/R+T+E group).In I/R+T and I/R+T+E groups,tyrosol 20 mg · kg-1 · d-1 was given by gavage for 45 consecutive days,and the equal volume of normal saline was given in the other two groups.In I/R+T+E group,EX527 5 mg · kg-1 · d-1 was intraperitoneally injected for 3 consecutive days before ischemia,and EX527 5 mg/kg was intraperitoneally injected at 20 min before repeffusion.Myocardial I/R was induced by ligation of the left anterior descending branch of coronary artery for 30 min followed by 2-h reperfusion.The myocardial infarct volume was measured by TTC staining.The levels of creatine kinase-MB (CK-MB),lactic dehydrogenase (LDH) and 5-F2t-isoprostane in serum and superoxide dismutase (SOD) in myocardial tissues were detected by enzyme-linked immunosorbent assay.The expression of SIRT1,AMPK,phosphorylated AMPK (p-AMPK),eNOS and p-eNOS was detected by Western blot.Results Compared with S group,the levels of serum CK-MB,LDH and 15-F2t-Isoprostane and myocardial infarction volume were significantly increased,the SOD activity was decreased,and the SIRT1 expression was down-regulated in I/R group,and the levels of serum CKMB,LDH and 15-F2t-Isoprostane and myocardial infarction volume were significantly increased,the SOD activity was decreased,the SIRT1 expression was down-regulated,and the expression of p-AMPK and peNOS was up-regulated in I/R+T and I/R+T+E groups (P＜0.05).Compared with I/R group,the levels of serum CK-MB,LDH and 15-F2t-Isoprostane and myocardial infarction volume were significantly decreased,the SOD activity was increased,and the expression of SIRT1,p-AMPK and p-eNOS was up-regulated in I/R+T group (P＜0.05),and no significant change was found in the parameters mentioned above in I/R+ T+E group (P＞0.05).Compared with I/R+T group,the levels of CK-MB,LDH and 15-F2t-isoprostane in serum and myocardial infarct volume were significantly increased,the SOD activity was increased,and the expression of SIRT1,p-AMPK and p-eNOS was down-regulated in I/R+T+E group (P＜0.05).Conclusion Tyrosol can mitigate myocardial I/R injury,and the mechanism may be related to activating SIRT1/AMPK/eNOS signaling pathway and inhibiting oxidative stress response in diabetic rats.