Carbenoxolone Ameliorates Allergic Airway Inflammation through NF-κB/NLRP3 Pathway in Mice

Asthma is a respiratory disease characterized by heterogeneous chronic airway inflammation. Activation of nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome is involved in the development of many pulmonary inflammatory diseases. The role and regulatory mechanism of carbenoxolone (CBX) in ovalbumin (OVA)-induced asthma models are not fully clear. Therefore, the study investigated whether CBX ameliorates airway inflammation and remodeling, as well as its mechanism in OVA induced-inflammation in mice. Wright-Giemsa staining was used to count inflammatory cells in bronchoalveolar lavage fluid (BALF). The level of inflammatory cells infiltration, mucus cell proliferation, and collagen deposition in lung tissue were separately assessed by hematoxylin and eosin, periodic acid-Schiff, and Masson trichrome staining, respectively. Airway resistance (AR) was measured by non-invasive airway system. Immunohistochemical assay was used to observe NLRP3 expression area. The expression of nuclear factor-kappaB (NF-κB), p-NF-κB, inhibitor of kappaB (IκB)-α, p-IκB-α, NLRP3, pro-caspase-1, caspase-1, and interleukin (IL)-1β in lung tissue were measured using quantitative real-time PCR or Western blotting. Our results showed that CBX can significantly attenuate the leukocyte count and the percentage of eosinophils and neutrophils in the BALF, peribronchial inflammation, airway mucus secretion, collagen deposition area, and AR in OVA-induced airway inflammation. In addition, the expression of p-NF-κB, p-IκB-α, NLRP3 and related factors were dramatically alleviated after CBX treatment. These data suggest that CBX has a significant protective effect on allergic airway inflammation by suppressing the activation of NLRP3 inflammasome through NF-κB pathway in asthmatic mice.