Abstract: AIM:To evaluate the effects of astragalus polysaccharide (APS) on the airway remodeling in asthmatic mice. METHODS: Sixty SPF BALB/c mouse were randomly divided into four groups: control group, asthmatic model group, APS treatment group and dexamethasone (DXM) treatment group. The experimental groups were sensitized with ovalbumin (OVA), cured with APS or DXM, then excited with 1%OVA. The method of two-step immunohistochemistry and techniques of computer-assisted image analysis were used to detect the changes of the airway remodelling and the expression of α-SMA. RESULTS: Compared with those in the control group, in asthmatic model group, the counts of inflammation cells were significantly increased (P<0.01); the expression of α-SMA was strongly positive; while the wall thickness(d/Pi) and wall area(WA/Pi) of the bronchi were significantly increased(P<0.05 or P<0.01), and so did the area of smooth muscle(Wam/Pi) and the count of smooth muscle cells(N/Pi)(P<0.05 or P<0.01). Compared with the asthmatic model group, in both APS inhalation group and DXM treatment group, the results of α-SMA showed positive expression, the numbers of inflammation cells were notably decreased (P<0.01), there also were great decreases of d/Pi,WA/Pi,Wam/Pi and N/Pi. CONCLUSION: With the treatment of APS, the course of the airway remodeling can be inhibited. The regulation on the expression level of α-SMA may be one of the mechanisms controlling the airway remodeling.

Key words: Asthma, Airway remodeling, Astragalus polysaccharide, α-SMA