OBJECTIVE:To observe the effect of Xiaochuanping powder (XP),a traditional Chinese prescription for the treatment of cough and asthma,on serum concentrations of eosinophil cationic protein (ECP),tumor necrosis factor (TNF)-α,and interleukin (IL)-4,eosinophil counts,as well as expression of matrix metalloproteinase (MMP)-9,tissue inhibitor of metalloproteinase (TIMP)-1 in the lung tissues of asthmatic rats.METHODS-Sixty clean-grade Sprague-Dawley rats were divided randomly into six groups:normal control (NC),asthma model,Guilong Kechuanning (GK)group,as well as high-,intermediate-,and lowdose XP groups.Rats were sensitized with ovalbumin (OVA) to trigger asthma.Serum concentrations of ECP,TNF-α and IL-4,eosinophil counts,as well as expression of MMP-9 and TIMP-1 in lung tissues were evaluated using an immunofluorescence method,mRNA expression of MMP-9 and TIMP-1 was determined using real-time quantitative polymerase chain reaction.RESULTS;Compared with the asthma-model group,serum concentrations of ECP,TNF-α,and IL-4,and eosinophil counts decreased significantly in the high-and intermediate-dose XP groups and GK group (all P ＜ 0.01).Protein expression of MMP-9 and TIMP-1 decreased significantly in the high-and intermediate-dose XP groups and GK group (all P ＜ 0.01).Transcription of MMP-9 and TIMP-1 mRNA and the ratio of expression of MMP-9:TIMP-1 in lung tissue were significantly lower (P ＜ 0.01).CONCLUSION:XP can reduce TNF-α secretion,suppress the infiltration / activation of eosinophils,reduce serum concentrations of ECP and IL-4,reduce the protein and mRNA expression of MMP-9 and TIMP-1 in lung tissue,and regulate the balance between expression of MMP-9 and TIMP-1.In these ways,XP alleviated the inflammation and remodeling of the airways.