【摘要】 目的：探究重楼皂苷Ⅰ（PPⅠ）对脂多糖（LPS）诱导的小鼠急性肺损伤（ALI）的作用机制。方法：将小鼠随机分为对照（Control）组、LPS组、PPⅠ5 mg/kg组、PPⅠ10 mg/kg组、PPⅠ20 mg/kg组和地塞米松（DEX）组，每组8只。PPⅠ各组小鼠灌胃相应剂量PPⅠ，DEX组灌胃2 mg/kg DEX，对照组灌胃生理盐水预处理7 d，鼻腔滴入LPS(5 mg/kg)建立小鼠ALI模型。24 h后处死小鼠，收集肺组织和支气管肺泡灌洗液（BALF），检测肺湿/干重（W/D）值；HE染色观察肺组织损伤情况并评分；检测BALF中总蛋白含量、白细胞和巨噬细胞数；试剂盒检测一氧化氮（NO）、髓过氧化物酶（MPO）、超氧化物歧化酶（SOD）和丙二醛（MDA）含量；ELISA检测TNF-α、IL-1β、IL-6水平；Western blot检测小鼠肺组织中p38和AMPK的磷酸化及NLRP3、caspase-1、Nrf2和KEAP1的蛋白表达。结果：与对照组相比，LPS组小鼠肺组织发生病理性变化，肺损伤评分、W/D值、BALF中总蛋白含量、炎症细胞、氧化应激水平和炎症细胞因子含量明显升高（P<0.05,P<0.01）,p38磷酸化水平、NLRP3、caspase-1和KEAP1蛋白表达显著上调（P<0.01）,AMPK磷酸化水平和Nrf2蛋白表达显著下调（P<0.01）。与LPS组比较，PPⅠ（10 mg/kg和20 mg/kg）和DEX减轻了LPS诱导的ALI，肺损伤评分、W/D值、BALF中总蛋白含量、炎症细胞、氧化应激水平和炎症细胞因子含量明显降低（P<0.05,P<0.01）,p38磷酸化水平、NLRP3、caspase-1和KEAP1蛋白表达显著下调（P<0.05,P<0.01）,AMPK磷酸化水平和Nrf2蛋白表达显著上调（P<0.05,P<0.01）。结论：PPⅠ能够减轻LPS诱导的小鼠ALI，可能与p38-NLRP3/caspase-1和AMPK-Nrf2/KEAP1信号途径有关。更多还原

【Abstract】 Objective:To explore the mechanism of polyphyllin Ⅰ（PPⅠ）on acute lung injury(ALI) induced by lipopolysaccharide(LPS) in mice.Methods:Mice were randomly divided into Control group,LPS group,PPⅠ 5 mg/kg group,PPⅠ 10 mg/kg group,PPⅠ 20 mg/kg group and dexamethasone(DEX) group,with 8 mice in each group. Mice in each PPⅠ group were intragastrically administered with corresponding dose of PPⅠ,the DEX group was given 2 mg/kg DEX,the control group was given normal saline for 7 d,and LPS(5 mg/kg) was dripped into the nasal cavity to establish a mouse ALI model. Mice were sacrificed 24 h later,lung tissues and bronchoalveolar lavage fluid(BALF) were collected,and the lung wet/dry(W/D) weight value was detected;HE staining was used to observe lung tissue damage and score;total protein content and the number of white blood cells and macrophages in BALF were measured;the kits were employed to test the contents of nitric oxide(NO) ,myeloperoxidase(MPO) ,superoxide dismutase(SOD) and malondialdehyde(MDA) ;ELISA was performed to assay the levels of TNF-α,IL-1β,IL-6;Western blot was commended to detect the phosphorylation of p38 and AMPK and protein expressions of NLRP3,caspase-1,Nrf2 and KEAP1 in mouse lung tissue.Results:Compared with the control group,pathological changes occurred in the lung tissue of LPS group,the lung injury score,W/D value,total protein content,inflammatory cells,oxidative stress level and inflammation cytokine content in BALF were significantly increased(P<0.05,P<0.01) ,the phosphorylation level of p38 and the expressions of NLRP3,caspase-1 and KEAP1protein were significantly up-regulated(P<0.01) ,the phosphorylation level of AMPK and the expression of Nrf2 protein were significantly down-regulated(P<0.01) . Compared with the LPS group,PPⅠ（10 mg/kg and 20 mg/kg）and DEX alleviated LPS-induced ALI in mice. Lung injury score,W/D value,total protein content,inflammatory cells,and oxidation stress levels and inflammatory cytokine levels in BALF were significantly reduced(P<0.05,P<0.01) ,the phosphorylation level of p38 and the expression of NLRP3,caspase-1 and KEAP1 protein were significantly down-regulated(P<0.05,P<0.01) ,the phosphorylation level of AMPK and the expression of Nrf2 protein were significantly up-regulated(P<0.05,P<0.01) .Conclusion:PP Ⅰ can alleviate LPS-induced ALI in mice,which may be related to the p38-NLRP3/caspase-1 and AMPK-Nrf2/KEAP1 signal pathways.更多还原