Bufei Decoction Improves Lung-Qi Deficiency Syndrome of Chronic Obstructive Pulmonary Disease in Rats by Regulating the Balance of Th17/Treg Cells

Bufei decoction (BFD) has been applied to treat chronic obstructive pulmonary disease (COPD) for centuries as a recognized traditional Chinese herbal formula. However, mechanisms of BFD on COPD are unclear. This study conducts an inquiry into the underlying mechanisms of the therapeutic effect of BFD on COPD. A COPD rat model with qi deficiency in lungs was established through induction using cigarette and sawdust smoking combined with intratracheal instillation of lipopolysaccharide following BFD treatment for 28 days. Changes in Th17/Treg cells of COPD rats with the syndrome of lung qi deficiency after BFD administration were verified using pulmonary function, ELISA, flow cytometry, histopathology, and Western blotting assays. The findings showed that BFD protected COPD rats from decreased lung function and lung injury. BFD administration reduced proinflammatory cytokines IL-6 and IL-17 secretion, promoted inhibitory cytokines IL-10 and TGF-β secretion, decreased Th17/Treg cell ratio, markedly downregulated the Th17 cell transcription factor ROR-γt expression, and upregulated transcription factor Foxp3 expression in Treg cells. We speculate that lung tonic soup improved pulmonary qi deficiency in rats with COPD by regulating the balance of Th17/Treg cells.