Abstract: Objective To observe the effects of different doses of Yiqi Guben capsules on pathology and TGF-β1/Smad signaling pathway in airway remodeling of asthmatic mice.Method The 60 male SPF level BALB/c mice were randomly divided into normal group, model group, dexamethasone intervention(DSMS) group, Tongkang(TKP) group, Yiqi Guben capsules high dose(YQGBH) group and Yiqi Guben capsules low dose(YQGBL) group, with 10 mice in each group. Apart from the normal group, the other groups were sensitized and stimulated by ovalbumin to copy asthma model. On and from the 21st day, each group was given gavage with pure water and medicines 1 h prior to each excitation except the normal group.Observe pathological changes of airway and lung tissues in each group with HE staining, and detect expression of TGF-β1 and P-Smad3 protein in lung tissues with  immunohistochemistry.Result The trachea and lung tissue pathological change degree in model group was statistically higher than that of normal group, model group, DSMS group, TKP group, YQGBH group and YQGBL group according to airway pathological examination（P<0.05）；comparing DSMS group with YQGBH group and YQGBL group，the difference was not statistically significant(P>0.05).Compared with normal group，TGF-β1 protein expression levels in model group, DSMS group, TKP group, YQGBH group and YQGBL group statistically increased（P<0.01）； compared with model group, TGF-1 protein expression levels statistically decreased in DSMS group, TKP group, YQGBH group and YQGBL group（P<0.01）； comparing DSMS group with YQGBH group and YQGBL group，there was no statistical significance（P>0.05）；comparing YQGBH group with YQGBL group，the difference was not statistically significant（P>0.05）；compared with normal group, the expression levels of P-Smad3 protein increased in DSMS group, TKP group, YQGBH group and YQGBL group（P<0.01）；compared with model group, the P-Smad3 protein expression levels decreased in DSMS group, TKP group, YQGBH group and YQGBL group with statiscal significance（P<0.01）；the P-Smad3 protein expression level of  DSMS group was even lower than TKP group, YQGBH group and YQGBL group（P<0.01） and the difference was of statistical significance；comaring TKP group with YQGBH group, the difference was not statistically significant（P>0.05）；comparing YQGBH group with YQGBL group, there was no statistically significant difference（P>0.05）. Conclusion Yiqi Guben capsules can block TGF-β1 intracellular signal transduction by inhibiting excessive expression of TGF-β1 and P-Smad3 in asthma mice, which to a certain extent, reduces asthma airway inflammation in mice and inhibits the occurrence of airway remodeling.

Key words: asthma, Yiqi Guben capsules/therapeutic use, airway remodeling, TGF-β1, Smad3, mouse