Feikang granules ameliorate pulmonary inflammation in the rat model of chronic obstructive pulmonary disease via TLR2/4-mediated NF-κB pathway

PURPOSE: Several reports have shown that traditional Chinese medicine could be an alternative therapeutic approach for COPD patients, but the mechanism remains unknown. The present study aimed to examine the effects of Feikang granules in a COPD model rat and investigate the possible mechanisms via Toll-like receptor (TLR)/ nuclear factor kappa B (NF-κB) signaling. METHODS: The COPD model rats were treated with Feikang granules, dexamethasone, or normal saline. The pulmonary function; lung tissue histology; levels of inflammatory cytokines; mRNA levels of TNFα, IL-6, TLR4, and TLR2; and protein levels of TLR4, TLR2, p-IκB, IκB and P65 in lung tissues were evaluated. RESULTS: The present study confirmed that the pro-inflammatory cytokines, TNF-α, IL-1β, IL-6, and IL-17 levels were elevated and the pulmonary function and morphology are altered in COPD model rats. The TLR2 and TLR4 -mediated NF-kB signaling pathway plays a role in the mechanism of action. Feikang granules, a type of Chinese herbal medicine, significantly reduced LPS induced inflammatory cytokines release from lung tissue and alveolar macrophage in a dose-dependent manner. These medical herbs also prevented TLR2/4 and IκB downregulation and reversed the p-IκB and NF-κB p65 upregulation of the lung tissue in the COPD rats. Feikang granules were also found to protect against pulmonary dysfunction and pathological changes in the COPD rats. CONCLUSION: The Chinese herbal medicine formula Feikang granules prevent pulmonary inflammation and improve pulmonary function, suggesting that Feikang granules may be an effective treatment for chronic pulmonary diseases, such as COPD.