Background: The three Tiao-Bu Fei-Shen (Bufei Jianpi, Bufei Yishen, Yiqi Zishen) granules have been confirmed for their beneficial clinical efficacy in chronic obstructive pulmonary disease (COPD) patients on reducing frequency and duration of acute exacerbation, improving syndromes, pulmonary function and exercise capacity. But the short- or long-term mechanism of them is not fully clear. Nuclear factor (NF)-κB/transforming growth factor (TGF)-β1/smad2 signaling pathway is involved in the progress of inflammation and remodeling in chronic obstructive pulmonary disease COPD. This study aimed to explore the long-term effects mechanism of Tiao-Bu Fei-Shen granules by regulating NF-κB/TGF-β/Smads signaling in rats with COPD.
Methods: Sprague Dawley rats were randomized into control, model, Bufei Jianpi, Bufei Yishen, Yiqi Zishen and aminophylline groups. COPD rats, induced by cigarette smoke and bacterial infections exposures, were administrated intragastricly by normal saline, Bufei Jianpi, Bufei Yishen, Yiqi Zishen granules or aminophylline from week 9 through 20, respectively. At week 20 and 32, lung tissues were harvested. Immunohistochemistry was used to detect interleukin (IL)-1β and tumor necrosis factor (TNF)-α, quantitative real-time polymerase chain reaction (qRT-PCR) was used for TGF-β1 and Smad2 mRNA analysis, western blotting was used to determine the phosphorylation of NF-κB (p-NF-κB) and IκBα (p-IκBα).
Results: COPD rats had marked airway injury, such as chronic airway inflammation and remodeling, emphysema, which were improved in the three traditional Chinese medicines (TCM)-treated animals. The levels of IL-1β, TNF-α, p-NF-κB, p-IκBα, TGF-β1 and Smad2 were significantly higher in COPD rats than in controls, while they were dramatically reduced in the three TCM- and aminophylline-treated groups. At the meantime, all these endpoints were significantly lower in three TCM-treated groups than in aminophylline group, especially in Bufei Jianpi and Bufei Yishen groups. Compared to week 20, all endpoints decreased significantly in three TCM groups at week 32.
Conclusion: The three Tiao-Bu Fei-Shen therapies can reduce pulmonary inflammation and remodeling in COPD and have significant long-term effects. NF-κB/TGF-β1/smad2 signaling might be involved in the mechanism.