目的 探讨木鳖子醇提物对过氧化氢（hydrogen peroxide，H₂O₂）诱导的SH-SY5Y神经细胞氧化应激损伤及Kelch样环氧氯丙烷相关蛋白1（Kelch-like ECH-associated protein 1，Keap1）/核因子E2相关因子2（nuclear factor erythroid 2-related factor 2，Nrf2）通路的影响。方法 采用200 μmol/L H₂O₂诱导SH-SY5Y细胞损伤，给予8、16、32 μg/mL木鳖子醇提物干预后，采用MTS检测细胞活力；采用流式细胞术分析细胞凋亡及活性氧（reactive oxygen species，ROS）水平；采用试剂盒测定超氧化物歧化酶（superoxide dismutase，SOD）活性及丙二醛（malondialdehyde，MDA）水平；采用qRT-PCR检测Nrf2、Keap1、血红素氧合酶-1（heme oxygenase-1，HO-1）、醌氧化还原酶1 [NAD(P)H quinone oxidoreductase 1，NQO1]、SOD1、SOD2、过氧化氢酶（catalase，CAT）、B细胞淋巴瘤-2（B-cell lymphoma-2，Bcl-2）、Bcl-2相关X蛋白（Bcl-2 associated X protein，Bax）mRNA表达；采用免疫荧光法检测Nrf2、Bcl-2蛋白表达；采用Western blotting检测Keap1、Bax蛋白表达。结果 与模型组比较，木鳖子醇提物可改善H₂O₂诱导的SH-SY5Y细胞形态，显著提高细胞活力（P＜0.001），降低细胞凋亡率和ROS、MDA水平（P＜0.05、0.01、0.001），提高SOD活性（P＜0.001），上调HO-1、NQO1、CAT、SOD1、SOD2 mRNA表达（P＜0.01、0.001），上调Nrf2、Bcl-2 mRNA及蛋白表达（P＜0.05、0.01、0.001），促进Nrf2入核，下调Keap1、Bax mRNA及蛋白表达（P＜0.05、0.001）。结论 木鳖子醇提物通过激活Nrf2/Keap1信号通路，提高抗氧化酶活性，抑制氧化应激损伤，并通过调控Bcl-2/Bax途径抑制细胞凋亡，从而发挥神经保护作用。

Objective To explore the effect of ethanol extract of Momordica cochinchinensis on hydrogen peroxide (H₂O₂)-induced oxidative stress damage in SH-SY5Y neuroblastoma cells and Kelch like ECH associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Methods 200 μmol/L H₂O₂ was used to induce SH-SY5Y cell damage, and after intervention with ethanol extract of M. cochinchinensis (8, 16, 32 μg/mL), MTS was used to detect cell viability; Cell apoptosis and reactive oxygen species (ROS) level were analyzed by flow cytometry; Reagent kit was used to measure the activity of superoxide dismutase (SOD) and level of malondialdehyde (MDA); qRT-PCR was used to detect the mRNA expressions of Nrf2, Keap1, heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase 1 (NQO1), SOD1, SOD2, catalase (CAT), B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax); Immunofluorescence method was used to detect the expressions of Nrf2 and Bcl-2 proteins; Western blotting was used to detect the expressions of Keap1 and Bax proteins. Results Compared with model group, ethanol extract of M. cochinchinensis could improve the morphology of SH-SY5Y cells induced by H₂O₂, significantly increase cell viability (P < 0.001), reduce cell apoptosis rate and levels of ROS, MDA (P < 0.05, 0.01, 0.001), increase SOD activity (P < 0.001), up-regulate HO-1, NQO1, CAT, SOD1, SOD2 mRNA expressions (P < 0.01, 0.001), up-regulate Nrf2, Bcl-2 mRNA and protein expressions (P < 0.05, 0.01, 0.001), promote Nrf2 nuclear entry, and down-regulate Keap1, Bax mRNA and protein expressions (P < 0.05, 0.001). Conclusion The ethanol extract of M. cochinchinensis exerts neuroprotective effects by activating Nrf2/Keap1 signaling pathway, increasing antioxidant enzyme activity, inhibiting oxidative stress damage, and regulating Bcl-2/Bax pathway to suppress cell apoptosis.

R285.5

广西科技重大专项项目（桂科AA17202040-2）；广西中药药效研究重点实验室（省级）系统性研究课题（20-065-38-A3）