三七皂苷Rg1抑制脂多糖诱导小胶质细胞激活的机制研究

目的:探讨中药有效成分三七皂苷Rg1(Ginsenoside Rg1,Rg1)对抑制脂多糖(lipopolysaccharide,LPS)诱导的小胶质细胞株BV-2细胞激活的机制。方法:用LPS刺激BV-2细胞构建激活模型,采用四甲基偶氮唑蓝比色法(MTT)检测Rg1对BV-2细胞的活力影响,蛋白质免疫印迹(Western Blot)方法检测不同浓度Rg1(10、20和40μmol/L)对磷酸化的核因子-κB抑制蛋白-α(inhibitorκB-α,IκB-α)和反应结合蛋白(cAMP-responseelement binding protein,CREB)以及促分裂原活化蛋白激酶(mitogen-activated protein kinases,MAPKs)家族的细胞外信号调节激酶(extracellular signal-regulated kinase 1/2,ERK1/2)、c-Jun氨基端激酶(c-Jun N-terminal kinase,JNK)和p38促分裂原活化蛋白激酶(p38 mitogen-activated protein kinase,p38 MAPK)等细胞信号通路蛋白的表达及其变化规律。结果:不同浓度的Rg1明显抑制了LPS诱导的磷酸化IκB-α和CREB蛋白表达以及MAPKs通路(ERK1/2,JNK,p38 MAPK)磷酸化蛋白表达,并且对p38 MAPK表达的影响呈剂量依赖性。结论:Rg1可能通过抑制MAPKs的磷酸化来调控LPS诱导的小胶质细胞株BV-2细胞激活,发挥其神经抗炎的作用。

The memchanism of ginsenoside Rg1 mediated inhibition of LPS-induced activation of microglial cells

Objective: The present study was designed to investigate the possible mechanisms of ginsenoside Rg1(Rg1)mediated inhibition in activation of murine microglial BV-2 cells stimulated with lipopolysaccharide(LPS).Methods: Inflammatory cell model was structured by LPS-stimulated microglial BV-2 cells.The cells were treated with Rg1(10,20 and 40 μmol/L) prior to LPS exposure and the effects of Rg1 on viability of BV-2 cells were measured by MTT assay The expression levels of cell signaling pathway protein inhibitor κB-α(IκB-α),cAMP-response element binding protein(CREB) and mitogen-activated protein kinases(MAPKs) family including extracellular signal-regulated kinase 1/2(ERK1/2),c-Jun protein N-terminal kinase(JNK) and p38 mitogen-activated protein kinase(p38 MAPK) were analyzed by Western Blot.Results: The results indicated that LPS(1 μg/ml,30 min) induced phosphorylation of ERK1/2,JNK and p38 MAPK),which was inhibited by pretreatment of BV-2 cells with different concentrations of Rg1(10,20,and 40 μmol/L).Rg1 also blocked LPS-induced phosphorylation of IκB-α and CREB.In addition,Rg1 dose-dependently inhibited the increased expression of p38 MAPK protein stimulated by LPS.Conclusion: This study indicates that the Rg1 exerts its anti-neuroinflammatory actions significantly attenuation of LPS-induced activation of microglial cells through inhibition of phosphorylation of MAPKs.