[Effects of xinfeng capsule on myocardial fibrosis in adjuvant arthritis rats and its mechanism research]

To study effects of Xinfeng Capsule (XFC, a Chinese herbal compound for benefiting qi, invigorating Pi, and dredging col laterals) on myocardial fibrosis in adjuvant arthritis (AA) rats and its mechanism study.Sixty male Wistar rats were randomly divided into the normal control (NC) group (n = 12) and the model control (MC) group (n =48). Except rats in the NC group, Freund's complete adjuvant (0. 1 mL) was intracutaneously injected from the right hind limb to prepare the AA rat model. On the 19th day of inflammation rats in the AA model group were randomly divided into four groups, i.e., the XFC group, the methotrexate (MTX) group, the Tripterygium wilfordii polycoride Tablet (TPT) group, and the MC group, 12 in each group. Rats were sacrificed after 30-day medication. The myocardial ultrastructure was observed under transmission electron microscope. The mRNA and protein expression levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were detected using RT-PCR and Western blot respectively.(1) Results under electron microscope showed obvious hyperplasia of collagen fibers in myocardial cells of AA rats, which indicated the trend of myocardial fibrosis. The myocardial ultrastructural changes could be effectively improved in the MTX group, the TPT group, and the XFC group. The morphology of myocardial cells in the XFC group was contact, with clear nucleus, and little collagen fibers, which was better than the other groups. (2) Compared with the NC group, the mRNA and protein expression levels of MMP-9 in the myocardial tissue of the MC group were obviously up-regulated, while the mRNA and protein expression levels of TIMP-1 were obviously down-regulated (P0. 01). The mRNA and protein expression levels of MMP-9 decreased, and the mRNA and protein expression levels of TIMP-1 obviously increased in the XFC group, showing statistical difference when compared with the MC group (P0. 5, P0. 01).XFC could effectively inhibit the myocardial fibrosis of AA rats.lts mechanisms might be correlated with inhibiting the mRNA and protein expression levels of MMP-9, improving the mRNA and protein expression levels of TIMP-1, adjusting the balance of MMP-9/TIMP-1 ,and improving the metabolism of myocardial extracellular matrix.