| Objective:In this study, the acute lung injury(ALI) in mice was induced with intratracheal instillation of lipopolysaccharide (LPS) solution to explore the protective mechanism of Lianhuaqingwen capsule in vivo through observing the expression changes of junction protein, inflammatory factor and the expression of signal transduction related proteins in the lung tissueMethods:1. Pathological comparison of acute lung injury induced with LPS and Graphite powder:The mice mortality was recorded, and pathological changes of the lung tissues were examined by light and transmission electronic microscope.2. Effects of Lianhuaqingwen capsules on lung tissue injury and junction protein expression in ALI mice induced by LPS:The mice were sacrificed to to observe the pathological changes by microscopy and ultrastructure of alveolar epithelium by transmission electron microscopy in the lung tissue. The expressions of connexin-43(Cx43), occludin and zohula occludens protein-1 (ZO-1) in lung tissues was detected by immunohistochemistry.3. Effects of LHQW on inflammatory cytokines in ALI mice induced by LPS:Flow cytometry was used to detect the expression rate of TNF-a, IL-6 in whole blood. ELISA was adopted to determine the MPO content in lung tissue. Western Blot was employed to analyse the protein expression of neutrophil elastase (NE) in lung tissues, and real-time quantitative PCR. was used to measure the mRNA expression of monocyte chemotactic protein-1 (MCP-1) in the lung tissue.4. Influence of LHQW on NF-kappa B signaling pathway in ALI mice induced by LPS:Western Blot was used to detect the protein expression of NF-κB p65、IκBα、p-IκBα、IKKβ in lung tissues.Results:1. Pathological comparison of acute lung injury induced with LPS and Graphite powder:Compared with the normal group, there appeared obvious infiltration of a large number of macrophages in the lung tissues of group G, however, neutrophils was found in the lung tissues of group L. The mortality rate of mice increased gradually with the extension of time treating with G and L.2. Effects of Lianhuaqingwen capsules on lung tissue injury and junction protein expression in ALI mice induced by LPS:Compared with the LPS group, inflammatory cells infiltrationunder the light microscop was reduced on the different extent in four treatment groups. The alveolar epithelial cells of LPS group mice showed remarkedly injury under the electronic microscope. Compared with the LPS group, the damages also were relieved in four treatment groups. The expressions of Cx43, occludin and ZO-1 of lung tissue in LPS group were lower than that of normal group, but those in four groups were treatment groups increased obviously, compared with LPS group.3. Effects of LHQW on inflammatory cytokines in ALI mice induced by LPS:Compared with the normal group, the expression rate of TNF-a and IL-6 in the peripheral blood and the content of MPO, the protein expression of NE, the mRNA expression of MCP-1 in lung tissue in LPS group were increased significantly. Compared with the LPS group, those were lowered significantly in all LHQW groups.4. Influence of LHQW on NF-kappa B signaling pathway in ALI mice induced by LPS:Compared with the normal control group, the expression of NF-κB p65、IκBα、p-IκBα、IKKβin lung tissue were increased significantly in LPS group. Compared with the LPS group, the expression of NF-κB p65、IκBα、p-IκBα、IKKβ were decreased significantly in the LHQW treatment groups.Conclusion: LPS could induce lung inflammatory cells aggregation mainly including neutrophils, promote inflammatory factors releasing, which triggered and amplified of inflammatory response, eventually leading to acute lung injury. LHQW could exert protective effects on the lung injury through reducing the lung ultrastructure damage, inhibiting the accumulation of inflammatory cells, increasing the expression of intrapulmonary multiple junction protein, reducing the content of inflammatory factors, and inhibiting the activation of NF-kappa B signaling pathway in lung tissue. |
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