【摘要】 文章以料液比、提取温度、提取时间为参数，在单因素试验的基础上，采用响应面法优化多花黄精多糖(Polygonatum cyrtonema Hua polysaccharides, PCP)的提取工艺，并分离纯化得到水洗糖；采用氧化低密度脂蛋白(oxidized low-density lipoprotein, Ox-LDL)诱导巨噬细胞氧化应激为实验模型，研究PCP的抗氧化机制。结果显示，PCP的最佳提取工艺为：料液比1∶25,提取温度85℃,提取时间2.0 h。MTT实验结果表明，PCP对巨噬细胞不具有毒性；与模型组相比，PCP显著提高了巨噬细胞的总抗氧化能力(total antioxidant capacity, T-AOC)和谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)的酶活力，降低了丙二醛(MDA)的量，表明PCP具有较强的抗氧化功能。Western Blot实验结果显示，PCP显著上调了Nrf2的蛋白水平，抑制了Keap1的蛋白表达，提示PCP发挥抗氧化作用可能与调控Keap1/Nrf2信号通路有关。研究结果为PCP的深入开发利用提供了一定的理论基础。更多还原

【Abstract】 In this paper, a response surface methodology was employed to optimize the extraction process of Polygonatum cyrtonema Hua polysaccharides(PCP) by hot water based on single factor test, considering the parameters of ratio of raw material to water, extraction temperature and extraction time. The PCP was isolated and purified to obtain water-washed polysaccharides. The results showed that the optimal extraction parameters were as follows: ratio of raw material to water of 1∶25, extraction temperature of 85 ℃, and extraction time of 2.0 h. On this basis, the antioxidant mechanism of PCP was investigated using oxidized low-density lipoprotein(Ox-LDL)-treated macrophages. The MTT results indicated that PCP was not toxic to macrophages. Compared with the model group, PCP significantly increased the levels of total antioxidant capacity(T-AOC) and the activities of glutathione peroxidase(GSH-Px) and superoxide dismutase(SOD), and decreased the content of malondialdehyde(MDA), indicating that PCP could enhance antioxidant effects in Ox-LDL-induced macrophages. Furthermore, Western Blot experiments showed that PCP could also significantly up-regulate the protein level of Nrf2 and down-regulate the protein expression of Keap1 in Ox-LDL-induced macrophages. These results revealed that PCP could regulate oxidative stress in macrophages induced by Ox-LDL, which might be related to the modulation of Keap1/Nrf2 signaling pathway. The study results may provide a theoretical basis for the further development and utilization of PCP.更多还原