Long-Term Effects of TCM Yangqing Kangxian Formula on Bleomycin-Induced Pulmonary Fibrosis in Rats via Regulating Nuclear Factor-κB Signaling

OBJECTIVE: We aimed to evaluate the therapeutic effects and long-term effects of YKF and dissect the potential mechanisms. MATERIALS AND METHODS: IPF rats were given YKF, prednisone, or pirfenidone, respectively, from day 1 to day 42, followed by a 28-day nonintervention interval through day 70. Forced vital capacity (FVC), histopathology, hydroxyproline (HYP) contents, lung coefficient, blood inflammatory cell populations, inflammatory cytokine levels of the lung tissues, and the expression of proteins involved in nuclear factor- (NF-) κB signaling pathway were evaluated on days 7, 14, 28, 42, and 70. RESULTS: HYP contents, Ashcroft scores, lung coefficient, and pulmonary fibrosis blood cell populations increased significantly in IPF rats, while FVC declined. All the above-mentioned parameters were improved in treatment groups from day 7 up to day 70, especially in YKF group. The mRNA and protein expressions of tumor necrosis factor- (TNF-) α significantly decreased, while interferon- (IFN-) γ significantly increased, and phosphorylations of cytoplasm inhibitor of nuclear factor kappa-B kinase β (IKKβ), inhibitor of nuclear factor kappa-B α (IκBα), and NF-κB were obviously downregulated in YKF group from day 7 to day 70. CONCLUSION: YKF has beneficial protective and long-term effects on pulmonary fibrosis by anti-inflammatory response and alleviating fibrosis.