Cordyceps�sinensis inhibits airway remodeling in rats with chronic obstructive pulmonary disease

Abstract

<i>Cordyceps sinensis</i> is a traditional Chinese herbal medicine that has been used for centuries in Asia as a tonic to soothe the lung for the treatment of respiratory diseases. The aim of the present study was to determine the effects of <i>C. sinensi</i>s on airway remodeling in chronic obstructive pulmonary disease (COPD) and investigate the underlying molecular mechanisms. Rats with COPD were orally administered <i>C. sinensis</i> at low, moderate or high doses (2.5, 5 or 7.5 g/kg/day, respectively) for 12 weeks. Airway tissue histopathology, lung inflammation and airway remodeling were evaluated. <i>C. sinensis</i> treatment significantly ameliorated airway wall thickening, involving collagen deposition, airway wall fibrosis, smooth muscle hypertrophy and epithelial hyperplasia in model rats with COPD. Additionally, <i>C. sinensis</i> administration in rats with COPD reduced inflammatory cell accumulation and decreased inflammatory cytokine production, including tumor necrosis factor-α, interleukin-8 and transforming growth factor (TGF)-β1 in bronchoalveolar lavage fluid. Meanwhile, the increased levels of α-smooth muscle actin and collagen I in the COPD group were also markedly decreased by <i>C. sinensis</i> treatment. Furthermore, compared with untreated rats with COPD, <i>C. sinensis</i> reduced the expression level of phosphorylated (p)-Smad2, p-Smad3, TGF-β1 and its receptors, with the concomitant increased expression of Smad7 in the lungs of rats with COPD. These results indicated that treatment with <i>C. sinensis</i> may be a useful approach for COPD therapy.