[Liuwei Buqi Formula delays progression of chronic obstructive pulmonary disease in rats by regulating the NLRP3/caspase-1/GSDMD pyroptosis pathway].

Abstract

Objective: To explore the therapeutic mechanism of Liuwei Buqi (LWBQ) Formula for chronic obstructive pulmonary disease (COPD) in rat models.

Methods: SD rat models of COPD established by cigarette smoking combined with intratracheal lipopolysaccharide (LPS) instillation and hormone injection were treated with LWBQ Formula by gavage with or without intraperitoneal injection of MCC950 for 3 weeks, starting at the 5th week of modeling. After the treatments, the rats were examined for lung pathologies, lung function, total cell count and white blood cell count in bronchoalveolar lavage fluid (BALF), and serum levels of IL-6, TNF-α, IL-18 and NO. The mRNA expressions of NLRP3, ASC, caspase-1, GSDMD-N, IL-1β, and IL-18 in the lung tissue were detected with qRT-PCR.

Results: Compared with the normal control rats, the COPD rat models had severe lung pathologies and showed significantly decreased lung function, increased total cell and leukocyte subset counts in BALF, and increased serum levels of IL-6, TNF-α, IL-18 and NO and mRNA expressions of pyroptosis-related proteins in the lung tissue. Treatment of the rat models with LWBQ Formula significantly improved lung pathology and lung function, reduced total cell and leukocyte counts in BALF, and decreased serum levels of the inflammatory factors and expressions of pyroptosis-related proteins in the lung tissue. The combined treatment with MCC950 further improved lung pathology and function in spite of a significant difference, but BALF cell counts, serum inflammatory factor levels and pulmonary expressions of pyroptosis-related proteins were all significantly reduced following the treatment.

Conclusion: LWBQ Formula can delay the progression of COPD in rats possibly by inhibiting lung tissue pyroptosis via regulating the NLRP3/caspase-1/GSDMD pathway to reduce inflammatory response and lung damage.