ABSTRACT
Objective:To observe the effect of Jinxiangdan （JXD） on NOD-like receptor pyrin domain-containing-3 （NLRP3）/cysteine-dependent aspartate-directed protease-1 （Caspase-1）/interleukin-1<italic>β</italic> （IL-1<italic>β</italic>） signaling pathway in myocardium of rats with myocardial ischemia-reperfusion injury （MIRI） and explore the protective effect and mechanism of JXD against MIRI. Method:Fifty male SD rats were randomly divided into the sham operation group， model group， high- and low-dose JXD groups， and positive drug （Di'ao Xinxuekang） group， with 10 rats in each group. Seven days before modeling， rats in the JXD groups were separately treated with intragastric administration of 0.72 and 0.18 g·kg<sup>-1</sup> JXD tablets， the ones in the sham operation group and model group with the same volume of normal saline， and those in the positive drug group with 1.29 g·kg<sup>-1</sup> Di'ao Xinxuekang. Twelve hours after the last intragastric administration， the anterior descending branch of the left coronary artery was ligated for 30 min and then re-perfused for 60 min for inducing MIRI. ST segment elevation was detected by electrocardiogram（ECG） for model evaluation. The contents of creatine kinase （CK） and lactate dehydrogenase （LDH） in cardiac tissue were measured by colorimetry. Hematoxylin-eosin （HE） staining was conducted for observing myocardial histopathological changes， followed by the detection of cardiomyocyte apoptosis by DNA in situ nick end-labeling （TUNEL） assay. The protein and mRNA expression levels of NLRP3， Caspase-1， and IL-1<italic>β</italic> were detected by Western blot and real-time polymerase chain reaction （Real-time PCR）， respectively. Result:Compared with sham operation group， the model group exhibited obviously elevated ST segment （<italic>P</italic><0.01）， enhanced CK and LDH activities in the myocardium （<italic>P</italic><0.01）， increased apoptotic cardiomyocytes （<italic>P</italic><0.01）， and up-regulated NLRP3， Caspase-1， and IL-1<italic>β</italic> protein and mRNA expression （<italic>P</italic><0.01）. Compared with model group， JXD at both the high and low doses and Di'ao Xinxuekang significantly lowered the ST segment （<italic>P</italic><0.05，<italic>P</italic><0.01）， diminished the CK and LDH activities in myocardial tissue （<italic>P</italic><0.05，<italic>P</italic><0.01）， improved the apoptosis of cardiomyocytes （<italic>P</italic><0.05，<italic>P</italic><0.01）， and down-regulated the mRNA and protein expression levels of NLRP3， Caspase-1， and IL-1<italic>β</italic> in myocardial tissue （<italic>P</italic><0.05，<italic>P</italic><0.01）. The ST segment of ECG in the low-dose JXD group was increased as compared with that in the Di'ao Xinxuekang group （<italic>P</italic><0.05）， while the ST segment in the high-dose JXD group was obviously elevated （<italic>P</italic><0.05）. Besides， the green fluorescence intensities in the low- and high-dose JXD groups and the Di'ao Xinxuekang group remarkably declined （<italic>P</italic><0.05，<italic>P</italic><0.01）. The mRNA and protein expression levels of NLRP3， Caspase-1， and IL-1<italic>β</italic> in the high-dose JXD group were down-regulated （<italic>P</italic><0.05）. Conclusion:JXD alleviates MIRI possibly by lowering NLRP3 and IL-1<italic>β</italic> expression and inhibiting cardiomyocyte apoptosis.