中文摘要：

目的：探讨太白梅木皂苷的抗氧化作用，为进一步利用其防治疾病提供基础数据。方法：采用体外化学法检测太白槐木皂苷的总抗氧化能力。在细胞实验中，采用氧化剂叔丁基过氧化氢（tert—butyl hydroperoxide，tBHP）诱导细胞氧化损伤。设立相应对照组和药物保护组，给予太白槐木皂苷（5μg／mE）预处理保护，收集样品，流式细胞仪荧光法检测细胞活性氧（reactive oxygenspecies，ROS）水平，Westernblot方法检测抗氧化转录因子核呼吸因子2（nuclear respiratory factor2，NrC2）及其下游的血红素加氧酶1（heme oxygenase-1，HO-1）和谷氨酸半胱氨酸连接酶（Jy—glutamate—cysteineligase，GCL）的表达水平。结果：太白梅木皂苷体外实验检测总抗氧化能力表现出明显的剂量-效应关系。在细胞实验中，tBHP可以显著提高细胞ROS水平，引起细胞的氧化损伤，太白槐木皂苷预处理可以显著降低tBHP诱导的细胞ROS水平。同时发现太白梅木皂苷可以显著拮抗tBHP引起Nrf2及其下游的HO-1、GCL的催化亚基（GCLC）和调节亚基（GCLM）表达水平的升高。结论：太白槐木皂苷在化学反应体系及细胞水平，均显现出了抗氧化作用，具有抗氧化防治疾病的应用前景。

英文摘要：

The total antioxidant capacity of saponin was determined by ferric-reducing ability of plasma（FRAP） method. In the cellular study, tert-butyl hydroperoxide（tBHP） was employed as an oxidant to induce oxidative stress, and saponin （5μg/mL） was pre-incubated with the ceils 12 h before challenged by tBHP in the protective group. Then cellular ROS was labeled with DCFH-DA and determined by flow cytometry. The protein levels of nuclear respiratory factor 2 （Nrf2）, heme oxygenase-1 （HO-1）, γ-glutamate-cysteine ligase （GCL） were evaluated by Western blot. RESULTS： The saponin showed marked antioxidative effect, tBHP induced massive reactive oxygen species （ROS） production, for which saponin pre-treatment showed significant inhibition. Saponin pre-treatment also significantly inhibited the tBHP-stimulated protein expressions of Nrf2, HO-1 and GCL. CONCLUSION： Saponin from Aralia taibaiensis has potent antioxidative activity, indicating its potential clinical application in oxidative stress-related diseases. [KEY WORDS] Aralia taibaiensis; antioxidative; reactive oxygen species ; saponin; nuclear respiratory factor 2