Effect of esculin on acute lung injury induced by LPS in mice and possible mechanism

CHENG Xiao; YANG Ying-lin; LI Wei-han; WANG Yue-hua; DU Guan-hua

Abstract：Objective: To investigate the effects of esculin on acute lung injuries induced by lipopolysaccharide ( LPS) and explore its anti-inflammatory mechanism in mice. Methods: BALB/c mice were randomly divided into the following groups: normal control group, LPS model group, esculin 25, 50, and 100 mg·kg-1 treatment group.Pretreatment with esculin at dose of 25, 50, and 100 mg·kg-1 individually for 7 days, the model of lung injury in mice was established by intraperitoneal injection of LPS 5 mg·kg-1 on the 7 thday. After administration of LPS for6 h, the samples were taken for detection. The lung histological morphology was analyzed after HE staining. The levels of inflammatory factors and adhesion molecules in lung tissues by ELISA assay. Inflammatory pathway proteins including HMGB1 and TLR4 were analyzed by Western Blot. Results: Compared with the normal control, LPS induced alveolar capillary hyperemia, alveolar wall thickening, and release of inflammatory factors and adhesion molecules. In addition, both the inflammatory pathway proteins HMGB1 and TLR4 were significantly increased.However, treatment with esculin 25, 50 and 100 mg·kg-1 reduced lung injury induced by LPS, decreased release of inflammatory factors and adhesion molecule including IL-1β, IL-6, TNFα, MCP-1 and ICAM-1, and inhibited the expression of inflammatory proteins including HMGB1 and TLR4. Conclusion: Esculin can improve the acute lung injury and inflammation induced by LPS in mice, and its anti-inflammation mechanism may be related to downregulationof HMGB1/TLR4 inflammatory pathway.