Cynaroside reduces neutrophil extracellular trap formation and disease severity in a mouse model of asthma by inhibiting the COX-2/TNF-alpha/NF-kB axis.

Cynaroside is a plant extract from the perennial plant Anthriscus sylvestris that has been associated with relief of asthma symptoms. This study aims to investigate the effect and mechanism of cynaroside on neutrophilic asthma with cough in mice. A neutrophilic asthma with cough model was induced in female BALB/c mice using ovalbumin (OVA). Utilizing H&E and Periodic Acid-Schiff (PAS) staining, the histological features of the lungs were observed. The treatment effect was judged by measuring airway responsiveness. ELISA was used to identify immunoglobulin molecules in serum and bronchoalveolar lavage fluid (BALF). Capsaicin-induced cough was used to assess the frequency and latency of cough in mice. For neutrophil extracellular trap (NET) formation analysis, IF, ELISA, and WB were used. The increase in inflammatory cell infiltration and mucus secretion in lung tissue caused by OVA was lessened by cynaroside therapy. Cynaroside decreased OVA-induced IgE and IgG1/IgG2a levels. Furthermore, cynaroside also reduced the frequency of cough induced by OVA and prolonged cough latency. We also found that NET formation in lung tissue was blocked by cynaroside. Further mechanistic analysis revealed that cynaroside was found to alleviate cough and enhance pulmonary function by inhibiting the activity of the COX-2/TNF-a/NF-κB axis. Cynaroside was found to improve pulmonary function by inhibiting NET formation.