三七总皂苷通过抑制NF-κB转录活性改善LPS诱导小鼠急性肺损伤的研究

Panax notoginseng saponins ameliorated LPS-induced acute lung injury in mice by inhibiting the activation of NF-κB

急性肺损伤(acute lung injury,ALI)是一种以过度炎症反应为主的肺部疾病,临床上缺乏有效的治疗药物。本研究旨在探究三七总皂苷(Panax notoginseng saponins,PNS)对ALI的改善作用及潜在的作用机制。野生型C57BL/6J小鼠经气道滴注50μL 25 mg·mL脂多糖(lipopolysaccharide,LPS)溶液进行模型构建。24 h后,分别灌胃给予200和400 mg·kgPNS。给药24 h后通过检测肺功能、肺组织湿重干重比(W/D)、肺泡灌洗液(bronchoalveolar lavage fluid,BALF)总蛋白浓度、白介素6(interleukin 6,IL6)和肿瘤坏死因子α(tumor necrosis factorα,TNFα)的含量、肺组织Il6和Tnfα基因表达水平、肺组织病理学变化及BALF中炎性细胞的表达情况评价PNS对ALI小鼠的改善作用。进一步检测PNS在Raw264.7细胞和ALI小鼠肺组织中NF-κB及其上游激酶的蛋白表达水平,评价PNS改善ALI小鼠的潜在机制。实验方案经由上海中医药大学动物实验伦理委员会审查通过。本实验发现400 mg·kgPNS可以显著改善ALI小鼠肺功能,降低W/D、BALF中总蛋白、IL6和TNFα的含量,降低BALF中中性粒细胞的表达,减少肺组织炎性细胞浸润。在Raw264.7细胞和ALI小鼠肺组织中,PNS都能显著降低Nf-κb的基因表达,降低NF-κB的蛋白表达和磷酸化水平,促进IκBα的表达,抑制炎症反应。本研究表明,PNS可以抑制ALI小鼠肺组织NF-κB的活性,抑制炎症因子的释放和炎性细胞浸润,减轻肺部炎症,发挥改善ALI的作用。

Acute lung injury(ALI) is a kind of lung disease mainly caused by excessive inflammatory reaction.At present,there is a lack of effective therapeutic drugs in clinic.The aim of this study was to investigate the improvement effect of Panax notoginseng saponins(PNS) on ALI and its potential mechanism.The model of wildtype C57BL/6J mice was established by intratracheal instillation of 50 μL 25 mg·mLlipopolysaccharide(LPS).24 h later,200 and 400 mg·kgPNS was given intragastric,respectively.24 h after administration,the improvement effect of PNS on ALI mice was evaluated by lung function,wet-to-dry weight ratio(W/D),total protein,interleukin 6(IL6) and tumor necrosis factor α(TNFα) concentration of bronchoalveolar lavage fluid(BALF),expression levels of IL6 and TNFα in lung tissues,pathological changes of lung tissues and expression of inflammatory cells in BALF.The protein expression levels of NF-κB and its upstream kinases in Raw264.7 cells and ALI mice lung tissues were further detected to evaluate the potential mechanism of PNS improving ALI mice.The experimental scheme was approved by the Animal Experiment Ethics Committee of Shanghai University of Traditional Chinese Medicine.It was found that 400 mg·kgPNS could significantly improve the lung function of ALI mice,reduce the contents of W/D,BALF total protein,IL6 and TNFα,neutrophils expression in BALF and the infiltration of inflammatory cells in lung tissue.In Raw264.7 cells and ALI mice lung tissue,PNS significantly reduced the expression of NF-κB,reduced the protein expression and phosphorylation of NF-κB,promoted the expression of IκBα,and inhibited the inflammatory response.This study showed that PNS can improve ALI by inhibiting the activity of NF-κB,inhibiting the release of inflammatory factors and inflammatory cells infiltration,alleviating lung inflammation.