Résumé
Objective:To study the protective effect of Euphorbia helioscopia alcohol extract on lipopolysaccharide (LPS) -induced acute lung injury in mice and explore its possible mechanism. Method:The 50 Balb/c male mice were randomly divided into 5 groups, including normal group, model group, dexamethasone group (1.5 mg·kg-1), E. helioscopia alcohol extracts group (7.5，3.75 g·kg-1). Except for the normal group, the other groups used intranasal instillation of LPS to establish a model of acute lung injury in mice. The type and number of inflammatory cells in bronchoalveolar lavage fluid (BALF) were detected by automatic blood analyzer and Wright-Giemsa composite staining. The lung tissue damage was observed by hematoxylin-eosin (HE) staining. The contents of the inflammatory factors tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in BALF were detected by flow cytometry. The protein expressions of nuclear factor kappa-B p65(NF-κB p65), phospho-NF-κB p65 (p-NF-κB p65), inhibitor of NF-κBα (IκBα), phospho-IκBα (p-IκBα) in NF-κB pathway and c-Jun N-terminal kinase (JNK), phospho-JNK (p-JNK), p38 protein (p38), phospho-p38 (p-p38), extracellular regulated protein kinases (ERK1/2), phospho-ERK1/2 (p-ERK1/2) in mitogen-activated protein kinase (MAPK) pathway were determined by Western blot. Result:Compared with normal control group, the lung tissue of the model group showed obvious damage, in which a large number of inflammatory cells infiltrated, and the integrity of the alveoli was destroyed. Inflammatory factors TNF-α, IL-6 in BALF and p-NF-κB p65, p-JNK, p-p38, p-ERK protein expression levels in lung tissue were significantly increased (P<0.01). Compared with model group, the pathological damage of lung tissue in mice with high dose of E. helioscopia alcohol extract and dexamethasone positive group was significantly alleviated. The levels of TNF-α and IL-6 in BALF and the expression levels of p-NF-κB p65, p-JNK, p-p38 and p-ERK1/2 protein in lung tissue were significantly down-regulated (P<0.01). Conclusion:The E. helioscopia alcohol extract has a protective effect on LPS-induced acute lung injury in mice, its mechanism may be related to the regulation of the NF-κB/MAPK signaling pathway.
Résumé
In the present study, we investigated anti-inflammatory effects of Sangxingtang (SXT) on acute lung injury using a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. The cell counting in the bronchoalveolar lavage fluid (BALF) was performed. The degree of lung edema was evaluated by measuring the wet/dry weight (W/D) ratio. The superoxidase dismutase (SOD) and myeloperoxidase (MPO) activities were assayed by SOD and MPO kits, respectively. The levels of inflammatory mediators, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), were assayed by the enzyme-linked immunosorbent assay methods. Pathological changes of lung tissues were observed by Hematoxylin and eosin (HE) staining. The inflammatory signaling pathway-related proteins nuclear factor mitogen activated protein kinases (P38MAPK), extracellular regulated protein kinases (Erk), c-Jun N-terminal kinase (Jnk) and nuclear transcription factor (NF-κB) p65 expressions were measured by Western blotting. Our results showed that the treatment with the SXT markedly attenuated the inflammatory cell numbers in the BALF, decreased the levels of P-P38MAPK, P-Erk, P-Jnk and P-NF-κB p65 and the total protein levels in lungs, improved the SOD activity and inhibited the MPO activity. Histological studies demonstrated that SXT substantially reduced the LPS-induced neutrophils in lung tissues, compared with the untreated LPS group. In conclusion, our results indicated that SXT had protective effects on LPS-induced ALI in mice.