Abstract: This study aimed to explore the protective effect and mechanism of chlorogenic acid(CGA)on acute lung injury(ALI)in mice induced by activation of complement alternative pathway.32 healthy Kunming mice were randomly divided into four groups:the normal group,the model group,the resveratrol group and the CGA group,which received 7-day intragastric administration respectively.Then Cobra venom factor(CVF)was used to activate complement alternative pathway of Kunming mice by intravenous injection.Lung water content,BALF cell count,the protein content in bronchoalveolar lavage fluid(BALF)and myeloperoxidase(MPO)activity of lung homogenate were measured.The concentration of IL-6,TNF-α,P-selectin and ICAM-1 in BALF and serum was determined by ELISA.The pathological change of lung tissue was observed by HE staining.The phosphorylation of NF-κB p65 in lung tissues was checked by immunohistochemistry.The results showed that CGA reduced the protein concentration,the inflammatory cell count,the content of IL-6 and TNF-α in BALF and MPO activity of lung homogenate obviously.CGA also decreased the level of IL-6,TNF-α,P-selectin and ICAM-1 in serum,reduced the pulmonary inflammatory cell infiltration,and inhibited the phosphorylation of NF-κB p65 in ALI mice induced by activation of complement alternative pathway significantly.With these results,it is concluded that CGA can alleviate inflammatory response of ALI mice induced by activation of complement alternative pathway.The mechanism is highly related to the down-regulation of phosphorylation of NF-κB p65 and the decrease of inflammatory response.

Key words: chlorogenic acid, resveratrol, complement alternative pathway, acute lung injury, cobra venom factor, NF-&kappa, B p65