Icariin improves myocardial fibrosis induced by isoproterenol via regulating expression of a-SMA and MMPs/TIMP / 中国药理学通报

ABSTRACT

Abstract; Aim To explore the effect of icariin (ISO) in mice. Methods C57BL/6 mice were ran- (ICA) on myocardial fibrosis induced by isoproterenol domly divided into control group, ISO group, low-dose (15 mg • kg"1), middle-dose (30 mg • kg"1) and high-dose (60 mg • kg"1) of ICA-treated group and Losartan-treated group ( 9 mg • kg"1 ). The control group was subcutaneously injected with normal saline, and the other groups were subcutaneously injected with ISO (5 mg • kg"1, qd) continuously 14 days to established the myocardial fibrosis model. The ICA-treated groups and Losartan-treated group were simultaneously intragastrically administered of ICA or Losartan, respectively. And the other groups received the same a- mount of double distilled water. The left ventricular e- jection fraction (LVEF) and the left ventricular fraction shortening rate ( LVFS) were evaluated by the small animal ultrasound. The heart mass index (HMI) was calculated. The left ventricular collagen deposition was detected by Masson staining. The protein expressions of a-SMA, MMP-2, MMP-9 and TIMP-1 in the left ventricular tissue were detected by Western blot. Results ICA (30, 60 mg • kg"1) and Losartan could inhibit the decreased LVEF and LVFS, the increased HMI and left ventricular collagen deposition, the up- regulated a-SMA and MMP-9 protein expression, the down-regulated MMP-2 and TIMP-1 protein expression in the left ventricular tissues induced by ISO. Conclusions ICA can improve myocardial fibrosis induced by ISO in mice, and the underlying mechanism may be related to the regulation of the protein expression of a- SMA and MMPs/TIMP-1.