牡荆素对CVB3诱导的病毒性心肌炎大鼠心肌损伤的保护作用及机制研究

目的:探究牡荆素(Vitexin)对大鼠心肌损伤的保护作用及机制。方法:选择Balb/c新生乳鼠腹腔注射柯萨奇病毒B3(Coxsackie virus B3,CVB3)建立大鼠病毒性心肌炎模型,分别设置正常未感染组(对照组)、感染CVB3组(模型组)、CVB3+Vitexin (10 mg·kg^-1)组[简称Vitexin (10 mg·kg^-1)组]、CVB3+Vitexin (20 mg·kg^-1)组[简称Vitexin (20 mg·kg^-1)组]和CVB3+Vitexin (50 mg·kg^-1)组[简称Vitexin (50 mg·kg-1)组],连续腹腔注射给药1周。HE染色观察心肌细胞损伤水平, TUNEL染色检测肿瘤细胞凋亡。免疫组织化学法和酶联免疫吸附实验(enzyme-linked immunosorbent assay,ELISA)检测心肌炎标记分子和心肌损伤标记物。利用蛋白质免疫印迹(Western Blot)技术检测肿瘤凋亡及其下游靶基因等相关分子表达。结果:与对照组比较,模型组细胞受损严重,炎症因子、心肌损伤标志物及细胞凋亡因子显著升高(P<0.05), TGF-β1及TNF-α蛋白活性显著升高(P<0.05)。相较于模型组,Vitexin处理组心肌细胞形态正常,心肌纤维排列整齐;细胞凋亡显著减少;Vitexin处理组心肌炎症因子、心肌损伤标志物及细胞凋亡因子显著低于模型组(P<0.05)。TGF-β1及TNF-α蛋白活性显著降低(P<0.05);并且Vitexin高剂量优于低剂量组。结论:Vitexin可以减少细胞凋亡,降低炎症因子水平来保护心肌炎症细胞受到CVB3病毒诱导的损伤;Vitexin可能是通过抑制TGF-β1及TNF-α蛋白活性来发挥影响。

Protective effect and mechanism of Vitexin in treatment of viral myocarditis induced by CVB3

OBJECTIVE To investigate the function and mechanism of Vitexin on myocardial injury in rat models. METHODS Rat viral myocarditis model was established by intraperitoneal inoculation with Coxsackie virus B₃ in Balb/c new born rats. The rats were randomly divided into normal uninfected group (control group), infected CVB3 group (model group), CVB3+Vitexin (10 mg·kg^-1) group[referred to as Vitexin (10 mg·kg^-1) group], CVB3+Vitexin (20 mg·kg^-1) group[referred to as Vitexin (20 mg·kg^-1) group] and CVB3+Vitexin (50 mg·kg^-1) group[referred to as Vitexin (50 mg·kg^-1) group], and all rats of above groups were intraperitoneal inoculated for 7 d. Cell morphology was observed by HE staining, and tumor cell apoptosis was detected by TUNEL staining. Immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) were used to detect myocarditis marker molecules and myocardial injury markers. The expression of tumor apoptosis and its downstream target genes were detected by Western Blot. RESULTS Compared with the control group, the cells in the model group were seriously damaged, and the inflammatory factors, myocardial injury markers and apoptosis factors were significantly increased (P<0.05), and the protein activities of TGF-β1 and TNF-α were significantly increased (P<0.05). Compared with the model group, the myocardial cells in the Vitexin-treated group were normal in morphology, and the myocardial fibers were arranged in order; the apoptosis was significantly reduced; the myocardial inflammatory factors, myocardial injury markers and apoptosis factors in the Vitexin-treated group were significantly lower than those in the model group (P<0.05). The protein activities of TGF-β1 and TNF-α were significantly decreased (P<0.05), and the high dose of Vitexin was superior to the low dose group. CONCLUSION Vitexin can reduce cell apoptosis and reduce the level of inflammatory factors to protect myocardial inflammatory cells from CVB3 virus-induced injury; Vitexin may play a role by inhibiting the activity of TGF-β1 and TNF-α protein.