Electrical acupuncture moderately decreases cardiac ischemiareperfusion injury in rats

Restoration of blood flow to the ischemic myocardium termed reperfusion unavoidably leads to many heart complications (such as rhythm abnormalities, and sequentially heart failure), together with the induced damage of cardiomyocytes, which can worsen infarct size and is termed myocardial ischemia-reperfusion (I/R) injury. Electroacupuncture plays an important role in attenuating I/R injury. High mobility group box-1 protein (HMGB1) is upregulated in myocardial I/R injury and activates the inflammatory response which enhances the myocardial injury. In our study, we aimed to detect the roles of electrical acupuncture at Neiguan acupoints (PC6) in myocardial I/R injury and investigate the relationship between electrical acupuncture and HMGB1-related pathway. We found that electrical acupuncture pretreatment protected against myocardial I/R injury through inhibiting cell apoptosis. Electroacupuncture also decreased the expression levels of HMGB1 and inflammatory cytokines induced by I/R injury. In addition, the phosphorylation levels of JNK (c-Jun N-terminal kinase) was decreased by electroacupuncture in heart tissues. Furthermore, the effects of electrical acupuncture pretreatment were abrogated by the additional administration of recombinant HMGB1. Finally, the SP600125 administration, a selective JNK inhibitor, attenuated HMGB1-dependent cell apoptosis and cytokines release in myocardial I/R injury. In conclusion, our data demonstrate that electrical acupuncture at PC6 plays a protective role in myocardial I/R injury, and this effect is associated with inhibited HMGB1-JNK pathway, which provides a beneficial therapeutic strategy for patients with myocardial I/R injury.