苦瓜素对小鼠柯萨奇B3病毒性心肌炎caspase3作用的研究

Effect of momordicin on caspase 3 in Balb/c mice myocarditis induced with CVB3

目的观察苦瓜素对病毒性心肌炎心肌组织caspase3活性、基因转录及相应蛋白质表达的影响，探索苦瓜素治疗病毒性心肌炎的机制。方法实验小鼠随机分为苦瓜素治疗组、生理盐水对照组及正常对照组和正常小鼠苦瓜素处理组。苦瓜素剂量为25mg·kg^-1·d^-1，1次／d，疗程7d。第15天后取小鼠心肌进行caspase3活性测定、HE染色心肌病理检查、心肌细胞凋亡检查、RT-PCR检测、caspase3，mRNA转录水平，免疫组化与免疫印迹测定caspase3蛋白表达。结果生理盐水对照组小鼠心肌组织caspase3活性明显增高、mRNA转录水平与相应蛋白质表达水平亦显著增加；苦瓜素治疗组caspase3活性明显抑制，caspase3mR—NA转录水平明显低于生理盐水对照组（0．012±0．008 VS 0．043±0．015，t=4．37，P〈0．01），凋亡细胞明显减少。结论苦瓜素通过抑制caspase3基因转录与蛋白质表达、抑制其活性，对Balb／c小鼠CVB3病毒性心肌炎具有明显的治疗作用。

Objective To observe the effect of momordicin on caspase 3 activation, mRNA transcription, and protein expression in the myocardium of Balb/c mice myocarditis induced with CVB3 , and to explore its therapeutical mechanism in myocarditis. Methods Fourweeks-old Balb/c mice induced with CVB 3 were randomly divided into four groups as follows： momordicin treatment group, vehicle control group, normal control group and momordicin group. Momordicin （25 mg · kg^-· d ^-1 ） were intraperitoneally administered daily from day 0 to 6. Caspase 3 activation, HE staining for Histopathology, RT-PCR for caspase 3 mRNA , immunohistochemistry, and western blot for caspase 3 protein expression, tunnel examination were performed on day 15 respectively. Results The caspase 3 activation, mRNA transcription and expression of caspase 3 were significantly increased in the myocardium of Balb/c mice myocaditis induced with CVB3 infection on day 15. The caspase 3 activation was inhibited completely, mRNA and protein expression of caspase 3 were suppressed significantly when momordicin was administered. And the level of caspase 3 mRNA transcription was lowered more evidently in the momordicin group than that of the control group（0. 012 ±0. 008 vs 0. 043 ±0. 015, t =4. 37, P 〈0.01 ）. Apoptosis bodies were significantly increased in the momordicin group. Conclusion Momordicin has prominent therapeutical effect on Balb/c mice myocarditis induced with CVB3 by inhibiting caspase 3 activation, and suppressing caspase 3 mRNA transcription and protein expression.