甘草素通过抗炎发挥对阿尔茨海默病的保护作用

The protective effect of liquiritigenin on Alzheimer's disease by inhibiting inflammation response

目的研究植物雌激素甘草素(liquiritigenin,LG)是否通过抗炎对阿尔茨海默病(Alzheimer’s disease,AD)发挥保护作用。方法 LG是从中药甘草中提取的一种黄酮类化合物单体,具有多靶向作用,如抗炎、抗氧化等。本实验用N2A细胞(神经瘤母细胞)作为正常对照细胞和稳定表达瑞士突变型淀粉样蛋白前体蛋白(amyloid precursor protein,APP)的N2A细胞(N2AAPP)作为AD细胞模型,结合LG处理,通过MTT、ELISA、Western blot、RT-PCR检测LG对AD模型细胞的细胞活性、雌激素受体(ERβ)、炎症相关蛋白NLRP3和caspase-1以及炎症因子IL-1β、TNF-α的影响。结果与正常的N2A细胞相比,N2A-APP细胞中APP、BACE1蛋白表达以及Aβ水平显著增加,说明N2A-APP作为AD模型细胞的有效性。MTT结果显示LG不影响N2A的细胞活力(P>0.05)。Westers blot结果显示,与正常N2A细胞相比,N2A-APP细胞内ERβ的表达显著下调,而LG处理可显著逆转ERβ的表达。Westers blot结果还发现,与正常细胞相比,N2A-APP细胞内炎症相关蛋白NLRP3和p-caspase-1蛋白表达显著增强,而LG处理可有效逆转NLRP3和p-caspase-1的表达上调(P<0.01)。相应地,RT-PCR结果发现,LG可显著降低N2A-APP细胞内炎症因子IL-1β、TNF-α的水平。结论甘草素可有效抑制AD模型细胞的炎症反应,其机制可能与其上调ERβ蛋白的表达有关。

To investigate whether liquiritigenin(LG), a dehydroalanine monomer compound extracted from natural planet licorice, is an anti-inflammatory agent in Alzheimer’s disease(AD), N2A-APP cells were selected and treated with LG, while normal N2A cells were taken as normal control. Cell activity of mouse neuroblastoma cell line N2A cells with treatment of LG was determined by MTT. Western blot was used to detect the expression of NLRP3 and caspase-1;real-time PCR was used to detect the expression of IL-1β and TNF-α. Data showed that the protein levels of Aβ, APP, BACE1 and PS1 in N2A cells were significantly lower than those in N2A-APP cells.MTT results showed that LG at different concentrations had no significant effect on N2A cells activity;Western blot showed that the protein level of ERβ in N2A-APP cells was significantly decreased, and LG treatment can significantly reversed the expression of ERβ. The expression levels of NLRP3 and p-caspase-1 proteins in N2A-APP were significantly increased, while LG treatment effectively reversed the upregulation of NLRP3 and p-caspase-1. Meanwhile, Real-time PCR results showed that the expression levels of IL-1β and TNF-α in N2A-APP cells were significantly reduced by LG. In conclusion, LG can inhibit the inflammation response in AD, and the mechanism may be related to upregulation of ERβ.