黄芪提取物对β-淀粉样蛋白损伤PC12细胞的保护作用研究

Neuroprotective effect of the extract of Astragalus against amyloid β-protein-induced injuries in PC12 cells

目的研究黄芪提取物（EA）对β-淀粉样蛋白（AIB）损伤PCI2细胞的保护作用，并初步探讨其作用机制。方法体外培养大鼠肾上腺髓质嗜铬细胞克隆化的PCI2细胞株．应用不同浓度（20、40、80μg／mL）EA作用于10μmol／LAβ23-25。损伤的PC12细胞，应用MTT法检测细胞存活率的变化，用荧光比色法和TUNEL染色分别检测PC12细胞胞内活性氧（ROS）水平和细胞凋亡率的变化。结果与模型组比较，3种浓度的EA均可使AIBⅢ；诱导的PCI2细胞MTT比色实验A570值增加，胞内ROS水平减少，细胞凋亡率降低，差异均有统计学意义（P〈0．05），且随着浓度的增加，作用越明显。结论EA可能通过抗氧化损伤和抑制细胞凋亡对抗Aβ的神经毒性，发挥神经保护作用．且这种作用呈浓度依赖性。

Objective To observe the neuroprotective effect of the extract of astragalus （EA） on cultured PC12 cells against amyloid β-protein （Aβ） -mediated cell toxicity and explore the possible mechanism. Methods PC12 cells were cultured in DMEM medium and treated with different concentrations（20,40,80μg/mL） of EA after exposure to 10 μmol/L Aβ. The survival rate of the cells was measured by MTT assay, and the accumulation of reactive oxygen species （ROS） in PC12 cells induced by Aβ25-35 was detected by fluorometric method. TUNEL assay was performed to analyze the cell apoptosis. Results Compared with the model group, EA treated group significantly increased the cell survival rate, decreased ROS production in the cells and lowered the apoptosis rate of Aβ25-35-treated PC12 cells in a concentration-dependent manner （P〈0.05）. Conclusion EA may reduce the injuries of PC12 cells induced by Aβ25-35 exposure, which is associated with the dose-dependent anti-oxidative and anti-apoptotic activities of EA.