Protective effect of diosmetin on viral myocarditis of CVB3-induced suckling mice by regulating macrophage M1/M2 type polarization / 中国药理学与毒理学杂志

ABSTRACT

Objective: To study the protective effect of diosmetin on viral myocarditis induced by coxsackie virus B3 (CVB3) by regulating macrophage M1/M2 type polarization. Methods: BALB/c suckling mice were given ip 0.1 mL CVB3 virus culture solution of 1×105pfu, which was recorded as DO. After 24 h (D1), diosmetin (Dio) 12.5, 25 and 50 mg·kg-1were ig given, respectively, 7 d in succession. At the end of the experiment, mean arterial pressure (MAP), heart rate (HR), left ventricular systolic pressure (LVSP), expression levels of serum creatine kinase (CK), creatine kinase MB isoenzyme (CK-MB) and myoglobin (Mb) were detected. The peripheral blood was collected to analyze and sort polarization of macrophage M1 and M2 in peripheral blood by flow cytometry. The pathological features of myocardial tissues were analyzed by HE staining and TUNEL staining. Western blotting was performed to detect the expressions of cleaved-caspase 3 and cleaved-caspase 9 in myocardial tissues. Macrophages were sorted from spleen tissues of suckling mice. After macrophages were treated with IFN-y 5 mg·L-1, CVB3 1×105pfu, Dio 20 μmol·L-1, CVB3 (1×105pfu)+Dio 20 μmol·L-1for 24 h, the expression levels of inducible nitric oxide synthase (iNOS) and arginase-1 (Arg-1) in cells were detected by Western blotting. Results: Compared with normal control group, MAP, HR and LVSP in model group were significantly decreased (P<0.05). Compared with model group, MAP, HR and LVSP were significantly increased in Dio 12.5, 25 and 50 mg·kg-1groups (P<0.05). Compared with normal control group, levels of CK, CK-MB and Mb in serum, and apoptosis rate of cardiomyocytes in model group were significantly increased (P<0.05), so were expression levels of cleaved-caspase 3 and cleaved-caspase 9 in myocardial tissues (P<0.05). Compared with model group, levels of CK, CK-MB and Mb in serum, and apoptosis rate of cardiomyocytes were significantly decreased in Dio 12.5, 25 and 50 mg·kg-1groups (P<0.05), so were expression levels of cleaved-caspase 3 and cleaved-caspase 9 in myocardial tissues (P< 0.05). Compared with normal control group, positive percentages of F4/80+iNOS\F4/80+TLR4+and F4/ 80+CD40+in peripheral blood of model group were significantly increased, while those of F4/80+CD14\ F4/80+Arg-1+ and F4/80+CD206t were significantly decreased (P<0.05). Compared with model group, the former three items in peripheral blood were significantly decreased in Dio 12.5, 25 and 50 mg·kg-1groups, while the latter three items were significantly increased (P<0.05). Both IFN-γ and CVB3 virus could up-regulate the expression of iNOS, and inhibit the expression of Arg-1. The Dio treatment could inhibit the expression of iNOS and up- regulate the expression of Arg-1. Compared with CVB3 virus alone group, the expression of iNOS was decreased, but the expression of Arg-1 was increased in CVB3 + Dio group (P<0.05). Conclusion: Dio can inhibit the activation of M1 type macrophage caused by viral infection, promote its development towards M2 polarization, and improve cardiac function of the viral myocarditis model.