Abstract:

Objective: To investigate the protective effect of schisandrin B (Sch B) on myocardial ischemia/reperfusion
injury (MI/RI) and its underlying mechanism so as to provide theoretical basis for new drug development of traditional
Chinese medicine (TCM) with defined activity and high efficiency against myocardial ischemia. Methods: Totally 60 male
Wistar rats were randomly divided into six groups: control group, reperfusion injury (MI/RI) group, Sch B 20, 40 and
80 mg/(kg·d) dose groups and positive control drug metoprolol group (MET, 2.5 mg/(kg·d)). Drug intragastric (ig)
administration was continued for three weeks before ischemia-reperfusion injury. General heart change and myocardial
pathological change were observed, Evans blue and NBT staining was conducted to determine infarction area, and changes
in serum enzymes and cytokines and cardiac function were measured at the end of the experiment. Results: Sch B could
significantly alleviate heart damage induced by MI/RI, reduce the infarction area, elevate SOD and NO levels in serum,
reduce MDA, CK-MB and LDH contents, improve myocardial function. Conclusion: Sch B has certain protective effects
against myocardial ischemia-reperfusion injury in rats, and its mechanism may be related to reducing oxygen free radical
release and protecting ischemic myocardium from MI/RI.

Key words: schisandrin B, myocardial ischemia/reperfusion injury, oxygen free radicals release