【摘要】 目的 观察金线莲提取物对脂多糖(LPS)诱导的急性肺损伤(ALI)模型小鼠的疗效并探讨其作用机制。方法 60只健康ICR小鼠随机分为正常组、模型组、地塞米松组和金线莲低、中、高剂量组。地塞米松组给予5.0 mg/kg地塞米松溶液腹腔注射,金线莲低、中、高剂量组分别给予1.3、2.6、5.2 g/kg的金线莲提取物灌胃,对照组和模型组给予0.9%氯化钠溶液灌胃,连续给药2 d。第3天对照组给予0.9%氯化钠溶液气管滴注,其余各组均给予5.0 mg/kg LPS构建ALI模型。造模后各组再给药1次。12 h后颈椎脱臼处死小鼠,获取肺组织及肺泡灌洗液。HE染色观察肺组织病理学变化,测定肺湿干比,ELISA法测定肺泡灌洗液中IL-6、单核细胞趋化蛋白-1(MCP-1)、IL-12/p70、IFN-γ、TNF-α和IL-10的水平,免疫组化法检测肺组织中髓过氧化物酶(MPO)、磷酸化细胞外信号调节激酶(p-ERK)、人核因子κB抑制蛋白α(IκBα)和磷酸化人核因子κB抑制蛋白α(p-IκBα)的蛋白表达水平,Western blot法检测肺组织中细胞外信号调节激酶(ERK)、p-ERK、c-Jun氨基末端激酶(JNK)、磷酸化c-Jun氨基末端激酶(p-JNK)、p38、磷酸化p38(p-p38)、腺苷酸-活化蛋白激酶α(AMPKα)、磷酸化腺苷酸-活化蛋白激酶α(p-AMPKα)、MPO蛋白相对表达量。结果 与对照组相比,模型组小鼠肺组织出现炎性病理变化,肺泡灌洗液中IL-6、MCP-1、IL-12/p70、IFN-γ、TNF-α和IL-10水平均显著升高(均P<0.01)。与模型组相比,金线莲高剂量组肺组织湿干比明显降低(P<0.01),肺泡灌洗液中IL-6、MCP-1、IL-12/p70、IFN-γ、TNF-α和IL-10水平均显著降低(均P<0.05),肺组织MPO、p-ERK、pIκBα蛋白表达水平均显著降低(均P<0.05),p-ERK、p-JNK、p-p38、p-AMPKα、MPO蛋白相对表达量均显著降低(均P<0.05)。结论 一定剂量金线莲提取物可有效保护LPS所致ALI,其作用机制可能与调节丝裂原活化蛋白激酶信号通路、减轻炎症反应有关。更多还原

【Abstract】 Objective To investigate the effects of Jinxianlian(JXL, Anoectochilus roxburghii) extract on lipopolysaccharide(LPS)-induced acute lung injury in mice and explore its mechanism. Methods Sixty healthy ICR mice were randomly divided into control group(CON), model group(LPS), dexamethasone(DEX) group, low-dose JXL extract(JXL-L)group, medium-dose JXL extract(JXL-M) group, high-dose JXL extract(JXL-H) group. DEX solution(5.0 mg/kg) was given by intraperitoneal injection in DEX group, different doses of JXL extract solution(1.3, 2.6, 5.2 mg/kg) were given by gavage in the JXL-L, JXL-M, and JXL-H groups, while the blank group and model group were given normal saline by gavage for 2 d.On the D3, mice in the normal group were instilled with normal saline through the nose, and the other groups were instilled with LPS(5.0 mg/kg) to induce acute lung injury(ALI). Twelve hours after the last administration, mice were sacrificed, and lung tissue and bronchoalceolar lavage fluid(BALF) samples were collected. The lung wit/dry weight ratio(W/D) was measured, and HE staining was used to observe the pathological changes of lung tissue. The levels of IL-6, monocyte chemoattractant protein-1(MCP-1), IL-12/p70, IFN-γ, TNF-α and IL-10 in BALF were measured by ELISA. The relative expression of myeloperoxidase(MPO), phosphorylated activated extracellular signal-regulated kinase(p-ERK), nuclear factor kappa-B(IκBα) and phosphorylated IκBα(p-IκBα) in lung tissue were measured by immunohistochemistry(IHC). The expression of related proteins ERK, p-ERK, c-Jun N-terminal kinase(JNK), phosphorylated JNK(p-JNK), p38,phosphorylated p38(p-p38), adenosine monophosphate actived protein kinase α(AMPKα), phosphorylated AMPKα(p-AMPKα), MPO in lung tissue was detected by Western blot. Results Compared with the control group, the model group displayed inflammatory pathological changes in lung tissue, and the levels of IL-6, MCP-1, IL-12/p70, IFN-γ, TNF-α and IL-10 in BALF were increased(all P<0.01). Compared with the model group, the pathological changes of the JXL-H group were attenuated, lung W/D, and the levels of IL-6, MCP-1, IL-12/p70, TNF-α, IL-10 in BALF were decreased, the relative expression of MPO, p-ERK and p-IκBα were decreased, while the expression of related proteins of p-ERK, p-JNK, p-p38,p-AMPKα and MPO in lung tissue were downregulated too(all P<0.01). Conclusion JXL extract with certein dose has a protective effect against LPS-induced acute lung injury in mice, which may be related to its inhibition of mitogen-activated protein kinase signaling pathway and the improvement of inflammatory response.更多还原