Recent Advance on Drug Therapy Related to Myocardial Ischemia Reperfusion Injury

Myocardial ischemia reperfusion injury (MIRI) means complete or partial artery obstruction of coronary artery, and ischemic myocardium will be recirculating in a period of time. Although the ischemic myocardium can be restored to normal perfusion, its tissue damage will instead be progressive. An aggravated pathological process. MIRI is a complex entity where many inflammatory mediators play different roles, both to enhance myocardial infarction-derived damage and to heal injury. Therefore, the research and development of drugs for the prevention and treatment of this period has also become the focus. This article first studied pathophysiology of MIRI, and reviewed the research progress of MIRI-related drugs. Research results show that: MIRI is inevitable for myocardial ischemia, with the possible to double damage via the ischemic condition. Therefore, it is a serious complication and one of the most popular diseases in the world. It has always been difficult to find an effective treatment for this disease, because it is difficult to explore the inflammation behind its pathophysiology.

Simvastatin Improves Myocardial Ischemia Reperfusion Injury through KLF-Regulated Alleviation of Inflammation

Objective. To clarify the protective effect of simvastatin on myocardial ischemia reperfusion injury (MIRI) and the underlying mechanism. Materials and Methods. The MIRI model in rats was firstly constructed. Twenty-four male rats were randomly assigned into the sham group, ischemia-reperfusion (I/R) group, and simvastatin group, with 8 rats in each group. Contents of superoxide dismutase (SOD) and malondialdehyde (MDA), as well as serum levels of CK and inflammatory factors, in rats were determined by the enzyme-linked immunosorbent assay (ELISA). Lactate dehydrogenase (LDH) activity in the three groups was examined. Through flow cytometry and Cell Counting Kit-8 (CCK-8) assay, apoptosis and viability in each group were detected, respectively. Relative levels of HMGB1, Kruppel-like factor 2 (KLF2), eNOS, and thrombomodulin (TM) were finally determined. Results. Simvastatin treatment markedly enhanced SOD activity and reduced contents of MDA, LDH, and creatine kinase (CK) in MIRI rats. The increased apoptosis and decreased viability following MIRI were partially reversed by simvastatin treatment. Besides, MIRI resulted in the upregulation of inflammatory factors and chemokines. Their elevations were abolished by simvastatin. In MIRI rats, simvastatin upregulated KLF2 and p-eNOS. Conclusions. Simvastatin protects inflammatory response at post-MIRI through upregulating KLF2, thus improving cardiac function.

Sodium-Glucose Co-transporter-2 Inhibitor of Dapagliflozin Attenuates Myocardial Ischemia/Reperfusion Injury by Limiting NLRP3 Inflammasome Activation and Modulating Autophagy

Background: The sodium-glucose co-transporter-2 (SGLT-2) inhibitor dapagliflozin improves cardiovascular outcomes in patients with type 2 diabetes in a manner that is partially independent of its hypoglycemic effect. These observations suggest that it may exert a cardioprotective effect by another mechanism. This study explored the effects of dapagliflozin on myocardial ischemia/reperfusion injury in a mouse model.Materials and Methods: For the in vivo I/R studies, mice received 40 mg/kg/d dapagliflozin, starting 7 days before I/R. Evans Blue/TTC double-staining was used to determine the infarct size. Serum levels of cTnI, CK-MB, and LDH were measured. Inflammation, autophagy protein expression, and caspase-1 activity changes were measured at the protein level. Primary cardiomyocytes were used to investigate the direct effect of dapagliflozin on cardiomyocytes and to verify whether they have the same effect as observed in in vivo experiments.Result: A high dose of dapagliflozin significantly reduced infarct size and decreased the serum levels of cTnI, CK-MB, and LDH. Dapagliflozin also reduced serum levels of IL-1β, reduced expression of myocardial inflammation-related proteins, and inhibited cardiac caspase-1 activity. The treatment restored autophagy flux and promoted the degradation of autophagosomes. Relief of inflammation relied on autophagosome phagocytosis of NLRP3 and autophagosome clearance after lysosome improvement. 10 μM dapagliflozin reduced intracellular Ca2+ and Na+ in primary cardiomyocytes, and increasing NHE1 and NCX expression mitigated dapagliflozin effects on autophagy.Conclusion: Dapagliflozin protects against myocardial ischemia/reperfusion injury independently of its hypoglycemic effect. High-dose dapagliflozin pretreatment might limit NLRP3 inflammasome activation and mediate its selective autophagy. Dapagliflozin directly acts on cardiomyocytes through NHE1/NCX.

Systems pharmacology dissection of the anti-myocardial ischemia-reperfusion injury mechanism for Ganjiang Fuzi decoction

Background: As the commonest form of ischemic heart diseases, the Myocardial Ischemia-Reperfusion injury (MI/RI) accounts for almost 50 percent of all deaths. The prevention and treatment of MI/RI while reducing the mortality of myocardial infarction has become a raging topic of research in the cardiovascular field. At present, there are no effective drugs for the treatment of MI/RI. Hence, it becomes imperative to identify or develop efficient lead compounds for treating MI/RI. It has been reported that the Ganjiang Fuzi Decoction (GFD) could be used for the effective treatment of MI/RI due to its promotion of vasodilation and vascular endothelial cell proliferation besides reducing the oxidative damage. Methods: The network pharmacological methods were used in this study, for analyzing the biological processes and the molecular mechanisms of the GFD for MI/RI treatment. In vitro and in vivo experiments were performed for verification of the results of the network pharmacological predictions. Results: Around 16 active components of GFD were discovered against MI/RI, where aconitine, 6-ginger, mesaconitine, and hypaconitine were the leading ones with regard to the degree value. Moreover, it was found that 88 MI/RI-related targets mainly involved six aspects, apoptosis, oxidative stress, inflammation, mitochondrial energy metabolism, and vasodilation. In vitro studies indicated the ability of the GFD to increase the survival rate, decrease the apoptosis rate, reduce oxidative damage, and increase the expression of HIF-1α, VEGF, and eNOS in hypoxia/reoxygenation(H/R) injured Rat Vascular Endothelial Cells (RVEC). The in vivo studies illustrated the capacity of the GFD to reduce the myocardial tissue damage and the infarction area, while increasing the expression of HIF-1α, VEGF, and eNOS in the MI/RI rats. Conclusions: The results of this study confirmed the anti-MI/RI role of the GFD through the activation of the HIF-1α signaling pathway, promotion of vascular proliferation and dilation, and the reduction in oxidative damage. The findings of this study would further provide experimental evidence for the application of the GFD in the treatment of MI/RI.