远志皂苷对β淀粉样蛋白1-40诱导的体外培养皮层神经细胞损伤的保护作用

Protective effect of tenuigenin on cytotoxicity of primary cultures of cortical neurons induced by amyloid beta-protein 1-40(Aβ_(1-40))

目的:研究远志皂苷(TEN)对β淀粉样蛋白1-40(A1β-40)诱导的原代培养神经细胞损伤的保护作用。方法:以原代培养大鼠皮层神经细胞,用25μmol.L-1聚集状的Aβ1-40建立神经细胞损伤模型。将培养的神经细胞分为A1β-40模型组和A1β-40+远志皂苷(50,100,200μmol.L-1)处理的低、中、高剂量组,同时设立正常组。在倒置显微镜下观察远志皂苷给药前后神经细胞的形态学变化,用MTT比色法检测神经细胞活性,采用LDH比色法检测神经细胞膜的损伤程度。结果:与正常组相比,25μmol.L-1Aβ1-40处理24 h,可使神经细胞的形态发生改变和活力显著下降,在显微镜下可见神经元失去贴壁能力或易脱落,突起变短。远志皂苷中、高剂量组均能显著降低神经细胞的坏死百分率,减少LDH的释放,明显提高神经细胞的存活率。结论:凝聚态Aβ1-40对培养的皮层神经细胞有一定的毒性效应,而远志皂苷对Aβ1-40引起的神经细胞毒性有明显的保护作用。

Objective： To observe the effect of tenuigenin（TEN） on aggregated amyloid beta-protein 1-40（Aβ1-40）-induced cytotoxicity of primary cultural cortical neurons in vitro. Method： In order to estabhsh neurotoxic model, the primary cultural rat cortical neurons were treated with 25 μmol·L^-1 aggregated Aβ1-40, which were divided into a model group and 3 different dose groups of TEN （50, 100,200 μmol·L^-1 , respectively）, and a normal control group with no treatment of Aβ1-40 was set up. The morphological changes of the neurons before and after administration of TEN were examined under a phase contrast microscope. Neuronal viabilities were detected by MTT colorimetry. Injuring degrees of the neuronal membrane were assessed by lactate dehydrogenase（LDH） colorimetry. Result： As compared with the normal control, treatment of primary cultural neurons with Aβ1-40（25 μmol·L^-1） for 24 h caused a significant decrease in viabilities and morphological changes of nerve cells, with neurons losing adherent ability or shedding, and the synapse shortening found by microscope. The percentage of apoptotic nerve cells and the LDH leakage were significantly decreased, and the survival rate of neurons was significantly increased in both the TEN high and medium dose groups. Conclusion： The aggregated Aβ1-40 has a definite neurotoxicity for cultural cortical neurons, and TEN can significantly protect the neurons from the cytotoxicity of Aβ1-40.