Paeoniflorin on Rat Myocardial Ischemia Reperfusion Injury of Protection and Mechanism Research

<b><i>Objective:</i></b> To study the myocardial benefit effect and mechanism of paeoniflorin on myocardial ischemia reperfusion injury (MIRI) in rats. <b><i>Methods:</i></b> Hundred SD rats were randomly divided into 5 groups: sham group, model group, Paeoniflorin (15 mg/kg) group, Paeoniflorin (30 mg/kg) group, and Paeoniflorin (60 mg/kg) group. Myocardial ischemia reperfusion model was established in each group except the sham group. The myocardial infarction and morphological changes were measured by the TTC staining and HE staining respectively. Myocardial caspase-3 was detected by immunohistochemistry. In addition, the protein levels of Bcl-2 and Bax and the expression ratio of p-erk, p-jnk, and p-p38 were detected by Western blot. Myocardial superoxide dismutase (SOD) activity and malondialdehyde (MDA) level were measured by the assay kit. <b><i>Results:</i></b> Paeoniflorin (30 mg/kg) and Paeoniflorin (60 mg/kg) can obviously alleviate myocardial infarction caused by MIRI (<i>p</i> &#x3c; 0.05). HE staining showed that the myocardial morphology in the treatment group was obviously better than that in the model group. WB and immunohistochemistry showed that Paeoniflorin (30 mg/kg) and Paeoniflorin (60 mg/kg) can significantly increase the reduced protein level of bcl-2 (<i>p</i> &#x3c; 0.05) and reduce the increased protein level of caspase3, bax ­p-erk, p-jnk, and p-p38 caused by MIRI (<i>p</i> &#x3c; 0.05). The activity of SOD was increased and the level of MDA was decreased after Paeoniflorin treatment. <b><i>Conclusion:</i></b> Paeoniflorin preconditioning has a protective effect on MIRI in rats. Its mechanism is related to reducing oxidative stress and apoptosis by inhibiting the expression of apoptosis-related signaling pathway.