Xiaoli Liu, Shanshan Zhang, Chaoyue Xu, Yongchao Sun, Shujian Sui, Zhaohua Zhang* and Yun Luan* Pages 1386 - 1393 ( 8 )
Background: The aim of this study was to explore the inhibitory effect of baicalin on myocardial apoptosis induced by ischemia-reperfusion (I/R).Methods: Sprague Dawley rats' heart and myocardial cells I/R model were established in vivo and vitro, then 100 mg/kg and 10 μmol/l baicalin were administrated, respectively. The experiment was randomly divided into 4 groups (n=10): Control; I/R; IR+DMEM; and I/R+baicalin groups. Postoperation, the left ventricular (LV) end-diastolic pressure (LVEDP), the maximum velocity of LV contraction (dP/dtmax) and the maximum velocity of LV diastole (dP/dtmin) were recorded by the transthoracic echocardiography; the myocardial apoptosis percentage was analyzed by Annexin V-FITC/PI and TUNEL staining, and the apoptosis gene and protein were detected by RT-PCR and western blot. Furthermore, the protein expression of the calcium-sensing receptor (CaSR) and ERK1/2 phosphorylation were observed by western blot and Fura-2-acetoxymethyl ester. Moreover, primary rats’ cardiomyocytes were cultured and ERK1/2 specific inhibitor PD98059 was added to the culture medium. The cell survival rate, vitality and apoptosis were detected by MTT, lactate dehydrogenase (LDH) and TUNEL staining assay Kit, respectively. Results: Our present study showed that baicalin significantly improved LV hemodynamic parameters and myocardial apoptosis in myocardial I/R injury rats. Furthermore, we found that baicalin could down-regulate the protein expression of CaSR, but up-regulate the protein expression of ERK1/2. Furthermore, when the cells were pretreated with ERK1/2 inhibitor PD98059, the cells survival rate significantly decreased, but LDH activity and apoptosis significantly increased. The results indicated that the effect of baicalin on myocardial I/R injury could be inhibited by ERK1/2 inhibitor. Conclusion: In conclusion, our data suggests that baicalin attenuates I/R-induced myocardial injury maybe through the suppression of the CaSR/ERK1/2 signaling pathway.
Baicalin, cardiomyocytes, I/R, apoptosis, CaSR, myocardial apoptosis.
Department of Hematology, The Second Hospital, Cheeloo College of Medicine, Shandong University, Department of Emergency, The Second Hospital, Cheeloo College of Medicine, Shandong University, Department of Pediatrics, The Second Hospital, Cheeloo College of Medicine, Shandong University, Department of Medicine, Jinan Vocational College of Nursing, Shandong, Department of Emergency, The Second Hospital, Cheeloo College of Medicine, Shandong University, Department of Pediatrics, The Second Hospital, Cheeloo College of Medicine, Shandong University, Institute of Medical Sciences, The Second Hospital, Cheeloo College of Medicine, Shandong University, No. 247, Beiyuan Dajie, Jinan, 250033