Inhibitory effects of modified gamgil-tang in a particulate matter-induced lung injury mouse model

Ethnopharmacological relevance The modified gamgil-tang (GGX) is a mixture of four herbal medicine including Platycodi Radix, Glycyrrhizae Radix, Lonicerae Flos and Mori Radicis Cortex which has been traditionally used to treat lung and airway diseases to relieve symptoms like sore throat, cough, and sputum in Korea. Its major component chlorogenic acid had been reported to have antioxidant, antibacterial, hepatoprotective, cardioprotective, anti-inflammatory, antiviral, and anti-microbial activity. Aim of the study To identify the inhibitory effect of GGX in a particulate matter (PM) induced lung injury mouse model. Materials and methods We evaluated NO production, the release of TNF-α and IFN-γ in PM-induced MH-S cells, and the number of neutrophils, immune cell subtypes, and the secretion of TNF-α, IL-17, CXCL-1, MIP-2 in the PM-stimulated mouse model to assess the inhibitory effect of GGX against PM. In addition, as exposure to PM increases respiratory symptoms, typically cough and sputum, we attempted to evaluate the antitussive and expectorant activities of GGX. Results Our study provided evidence that GGX has inhibitory effects in PM-induced lung injury by inhibiting the increase in neutrophil and inflammatory mediators, deactivating T cells, and ameliorating lung tissue damage. Notably, GGX reduced PM-induced neutrophilic inflammation by attenuating the number of neutrophils and regulating the secretion of neutrophil-related cytokines and chemokines, such as TNF-α, IL-17, MIP2, and CXCL-1. In addition, GGX demonstrated an antitussive activity by significantly reducing citric acid-induced cough frequency and delaying the latent period and expectorant activities by the increased phenol red secretion compared to the control group. Conclusions GGX is expected to be an effective herbal remedy to prevent PM-induced respiratory disease.