Abstract
Cigarette smoke (CS) is the main cause of chronic obstructive pulmonary disease (COPD), and continuous CS exposure causes lung inflammation and deterioration. To investigate the protective effects of Artemisia gmelinii against lung inflammation in this study, cigarette smoke extract (CSE)/lipopolysaccharide (LPS)-treated alveolar macrophages (AMs) and mice stimulated with CSE/porcine pancreas elastase (PPE) were used. Artemisia gmelinii ethanol extract (AGE) was effective in decreasing the levels of cytokines, chemokine, inducible nitric oxide synthase, and cyclooxygenase-2 by inhibiting mitogen-activated protein (MAP) kinases/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway in AMs. Additionally, oral administration of AGE suppressed inflammatory cells' infiltration and secretion of inflammatory cytokines, chemokines, matrix metallopeptidase 9, and neutrophil extracellular traps in bronchoalveolar lavage fluid from the COPD model. Moreover, the obstruction of small airways, the destruction of the lung parenchyma, and expression of IL-6, TNF-α, IL-1β, and MIP-2 were suppressed by inhibiting NF-κB activation in the lung tissues of the AGE group. These effects are associated with scopolin, chlorogenic acid, hyperoside, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 4,5-di-O-caffeoylquinic acid, which are the main components of AGE. These data demonstrate the mitigation effect of AGE on lung inflammation via inhibition of MAPK and NF-κB pathways, suggesting that AGE may be instrumental in improving respiratory and lung health.