Coniferyl aldehyde alleviates LPS-induced WI-38 cell apoptosis and inflammation injury via JAK2–STAT1 pathway in acute pneumonia

Pneumonia is a kind of inflammatory disease characterized by pathogen infection of lower respiratory track. Lipopolysaccharide (LPS) is the main bioactive component of Gram-negative bacteria responsible for inflammatory response. Recently, coniferyl aldehyde (CA) has been reported to play a crucial role because of its anti-inflammatory activity. However, the effect and mechanisms of CA in ameliorating symptoms of acute pneumonia remain unknown. Evaluating and identifying the value and exploring the mechanisms of CA on LPS-mediated WI-38 apoptosis and inflammation were the aims of this study. Here, CCK-8 cell viability assay was applied on WI-38 after treatment with or without LPS at different doses of CA to verify that CA can increase LPS-induced cell viability. Then, quantitative polymerase chain reaction (qPCR) and enzyme-linked-immunosorbent serologic assays (ELISA) suggested that LPS treatment dramatically decreased the expression level of IL-10 (anti-inflammatory factor) while strikingly increasing the expression levels of IL-1β, IL-6, and TNF-α (tumor necrosis factor-α; proinflammatory factor) whereas CA treatment attenuates LPS-induced inflammation of WI-38. Further, flow cytometry and Western blot assay verified that LPS treatment dramatically promoted apoptosis of WI-38 cells, while administration of CA notably inhibited apoptosis of WI-38 cells. Moreover, the Western blot assay hinted that CA could inactivate LPS-induced JAK2–STAT1 signaling pathway. These findings indicated that CA could alleviate LPS-mediated WI-38 apoptosis and inflammation injury through JAK2–STAT1 pathway in acute pneumonia.