Effects of the Traditional Chinese Medicine Dilong on Airway Remodeling in Rats with OVA-induced-Asthma

Abstract The present study focuses on the effects and suggests possible mechanisms of the traditional Chinese medicine Dilong as compared to dexamethasone on lower respiratory tract remodeling in rats with asthma. The number of leukocytes and eosinophils in blood from the inferior vena cava and bronchoalveolar lavage fluid (BALF) were counted. Lung tissues underwent hematoxylin and eosin staining. The thickness of the basement membrane and smooth muscle or the airways, and the ratio of inner to outer diameter of the airway wall were measured. Levels of transforming growth factor β1 (TGF-β1), matrix metallopeptidase 9/tissue inhibitor of metalloproteinase 1 (MMP-9/TIMP-1), urokinase plasminogen activator (uPA), plasminogen activator inhibitor 1 (PAI-1), and c-Myc(mRNA) were evaluated. Results indicate that treatment with Dilong decreased the number of eosinophils in blood and BALF, decreased levels of TGF-β1, MMP-9/TIMP-1, uPA, PAI-1 and c-Myc, and ameliorated the thickening of airway walls, airway basement membrane and airway smooth muscle. Co-treatment with dexamethasone was found to intensity these effects. The cellularity of eosinophils and thickness of the airway basement membrane and smooth muscle were positively correlated with levels of TGF- 1, uPA, and c-Myc. Treatment with Dilong, either alone or in combination with dexamethasone, could inhibit and partly reverse airway remodeling in rats with asthma at an early stage.