Effect of ligustrazine on airway smooth muscle proliferation and TGF-β_1 expression in asthmatic rats

Objective To observe the effect of ligustrazine on the proliferation of airway smooth muscle and the expression of transforming growth factor-β 1 (TGF-β 1) in asthmatic rats. Methods 32 SD rats were randomly divided equally into 4 groups:normal group, model group,low-dose ligustrazine group and high-dose ligustrazine group. The asthmatic rat model was established by repeated inhalation of ovalbulium. The changes of TGF-β 1 content in the wall of airway and the thickness of airway smooth muscle layer, inner and outer diameter were measured by the computerized image analysis system. Results The wall contents of TGF-β 1 and the thickness of airway smooth muscle layer were significantly higher ( P 0.001) in the model group than that in the normal group, while the ratio of inner diameter to outer diameter were lower ( P 0.001) .The contents of TGF-β 1 in both low-dose and high-dose ligustrazine group, were lower(P0.001)than that in the model group, and all close to the normal group ( P 0.05), the thickness of airway smooth muscle layer were lower (P0.001) too, but the ratio of inner diameter to outer diameter were higher (P0.001). A close correlation between the thickness of airway smooth muscle layer and contents of TGF-β 1 was demonstrated(r s=0.587-8, P0.01).Conclusion Ligustrazine could inhibit the airway remodeling by the way of reducing the proliferation of airway smooth muscle and the expression of TGF-β 1 in asthmatic.