Protective Mechanism of Velvet Antler Polypeptide on Myocardial Ischemia-Reperfusion Injury in Rats

Abstract

Velvet antler polypeptide (VAP) is the active compounds of velvet antler, an animal derived traditional Chinese medicine. In this work, the myocardial ischemia-reperfusion injury (MIRI) model was established to investigate the protective mechanism of VAP on MIRI in rats. Total 90 male Sprague Dawley (SD) rats were divided into the control, model (MIRI), positive (Diltiazem, DLZ, 20 mg/kg), VAP high, medium, low dose (VAP 300, 200, and 100 mg/kg) groups. After 21 days of intragastric administration, the electrocardiogram (ECG) changes in each group were detected. The activities of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) isoenzymes in serum, and superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px) and catalase (CAT) in myocardial tissue were detected by ELISA. Hematoxylin and eosin (HandE) staining was used to detect the histological changes of rat myocardium. Western blotting (WB) was used to detect the protein expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NADH quinone oxidoreductase 1 (NQO1) in rat myocardial tissue. In the results, ECG showed that the MIRI model was successfully established; VAP can significantly reduce the activities of LDH, CK-MB in serum of rats, increase the activities of SOD, GSH-Px, CAT in myocardial tissue, reduce the activity of MDA in myocardial tissue, reduce interstitial edema and inflammatory infiltration, and improve the structural damage of rat myocardial tissue. The expression levels of HO-1, NQO1 and Nrf2 protein in rat myocardial tissue were up-regulated. In conclusion, VAP can improve the structural damage of rat myocardial tissue, improve the antioxidant activity of myocardial, and reduce oxidative stress injury. The relevant mechanism may be related to the regulation of Nrf2/ARE signaling pathway in rat myocardial tissue by VAP.