SB203580 protects against inflammatory response and lung injury in a mouse model of lipopolysaccharide‑induced acute lung injury.

Acute lung injury (ALI) is characterized by acute hypoxic respiratory failure, pulmonary edema and inflammatory infiltration. ALI has a high mortality rate (~30%) in the clinical setting; therefore, focusing on the treatment of lung edema and inflammatory responses in ALI is of significance. The present study investigated the effect of the p38 mitogen‑activated protein kinase (p38MAPK) inhibitor, SB203580, on lung edema and inflammatory responses in ALI in vivo. A mouse model of ALI was established to assess the effect of SB203580 on edema, proinflammatory cytokine production, and the expression of interferon regulatory factor 5 (IRF5) and inducible nitric oxide synthase (iNOS) in lung tissues using immunoblotting, immunohistochemistry, immunofluorescence, hematoxylin and eosin staining, and ELISA. SB203580 inhibited LPS‑induced lung injury and proinflammatory cytokine expression, including tumor necrosis factor‑α and interleukin‑1β. SB203580 also downregulated LPS‑induced IRF5 and iNOS expression, which are widely used as markers of proinflammatory macrophages. Collectively, the present study demonstrated that SB203580 protected against inflammatory responses and lung injury by inhibiting lung edema and downregulating proinflammatory mediators in LPS‑induced lung injury.