Xiaoqinglong Decoction Attenuates Chronic Obstructive Pulmonary Disease in Rats via Inhibition of Autophagy.

Effective treatment for chronic obstructive pulmonary disease (COPD) and knowledge of the underlying mechanism are urgently required. Xiaoqinglong decoction (XQL) is widely used to treat COPD in Traditional Chinese Medicine, but the mechanism remains unclear. In this study, we tested the hypothesis that XQL ameliorates COPD via inhibition of autophagy in lung tissue on a rat model. Rats were divided into five groups, namely, Control group, COPD group, COPD + XQL group, COPD + Rapamycin group, and COPD + XQL + Rapamycin group. Pathological changes on cellular and molecular levels, apoptosis reflected by TdT-mediated dUTP Nick-End Labeling (TUNEL) assay, and autophagy represented by LC3II/LC3I ratio and p62 level were investigated for each group. Compared with the Control group, COPD rats exhibited structural changes and activated inflammation in the lung tissue, together with enhanced apoptosis and elevated autophagy biomarkers. XQL treatment significantly ameliorated these changes, while rapamycin augmented them. These data altogether confirmed the involvement of autophagy in the pathogenesis of COPD and suggested that XQL attenuates COPD via inhibition of autophagy.