OBJECTIVETo observe the effects of Dureping Injection on the contents of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in the lung tissue of mice with pneumonia of influenza virus infection.

METHODSSixty-six ICR mice were randomly divided into the normal group, the model group, the low, middle, and high dose Dureping Injection groups (0.435, 0.870, and 1.740 mg/d, respectively), and the positive control group (Ribavirin, 2.500 mg/d), 11 in each. The pneumonia of mice with influenza virus infection model was established using influenza virus strain FM1. Mice were intraperitoneally injected with 0. 3 mL FM1 starting from the infection day, once daily. Five days later mice were killed to calculate the lung index. The pathomorphological changes of the lung tissue were observed using routine HE stained sections. The contents of MMP-9 and TIMP-1 in the homogenate of the lung tissue were detected by ELISA double antibody sandwich method.

RESULTSCompared with the normal group, obvious inflammation occurred in the lung tissue of mice in the model group. The lung index, the content of MMP-9, and the value of MMP-9/TIMP-1 increased significantly in the model group (P < 0.01) , while the content of TIMP-1 was not significantly different (P > 0.05). Compared with the model group, the content of MMP-9 in the low and middle dose Dureping Injection groups, and the positive control group was significantly lowered (P < 0.01). The content of TIMP-1 in the low, middle, and high dose Dureping Injection groups, as well as the positive control group significantly increased (P < 0.01) and the value of MMP-9/TIMP-1 decreased (P < 0.01).

CONCLUSIONDureping Injection could alleviate the inflammatory injury of the lung tissue through decreasing the content of MMP-9, elevating the content of TIMP-1 in the lung tissue, and regulating the value of MMP-9/TIMP-1 of mice with pneumonia of influenza virus infection, thus alleviating the inflammatory injury of the lung tissue.