Preconditioning with glycyrrhizic, ferulic, paeoniflorin, cinnamic prevents rat hearts from ischemia/reperfusion injury via endothelial nitric oxide pathway

Objective: The objective was to investigate the endothelial nitric oxide synthase (eNOS/NO) pathway is involved or not in the protective effects of glycyrrhizic, ferulic, paeoniflorin, cinnamic (GFPC) in myocardial ischemia-reperfusion injury Sprague-Dawley rats. Materials and Methods: Ischemia-reperfusion (I/R) model was made by ligating the left anterior descending branch of the coronary artery for 30 min and releasing for 120 min, then the left ventricular apical was fixed and sliced, morphological changes of myocardial microvascular endothelial cell (MMVEC) was observed by electron microscopy, apoptosis index of MMVEC was observed by means of TUNEL, serum NO was tested by methods of nitrate reduction, lactate dehydrogenase (LDH), creatine kinase MB (CK-MB) was detected by automatic biochemical analyzer; Phosphorylated eNOS (PeNOS) and inducible NOS (iNOS) protein were measured by means of western blot. Results: In positive product control group, the serum levels of NO, LDH, CK-MB significantly increased (P < 0.05); MMVEC apoptosis was significantly decreased (P < 0.05); incidence of area at risk decreased significantly (P < 0.05); PeNOS protein increased (P < 0.05); iNOS protein decreased significantly (P < 0.05). Conclusion: Ischemic preconditioning of GFPC from GFPC plays a protective role in I/R heart through regulating the eNOS/NO signal pathway by increasing the PeNOS protein expression and decreasing the expression of iNOS protein.