基于秀丽隐杆线虫模型探讨白芥子水提物抗氧化作用及机制

摘 要：目的 研究白芥子水提物抗氧化活性，探讨其抗氧化的相关机制。方法 采用2,2-联苯基-1-苦基肼基(2,2-Diphenyl-1-picrylhydrazyl，DPPH)自由基、羟基自由基、铁离子还原能力3种方法对其体外抗氧化活性进行评价。采用秀丽隐杆线虫野生型N2线虫观察白芥子水提物对线虫寿命、运动能力、生殖能力的影响；通过氧化应激、热应激、脂褐素和活性氧(reactive oxygen species, ROS)评估其对线虫抗氧化能力的影响。采用实时荧光定量技术测定白芥子水提物作用下线虫抗氧化、胰岛素信号途径相关基因表达情况。结果 白芥子水提物具有一定的DPPH·、羟基自由基清除能力。通过氧化应激筛选出最佳给药浓度为10 mg/mL，且该给药浓度对线虫的运动能力和生殖能力无影响(P>0.05)，并能够显著延长线虫的平均寿命和中位寿命(P<0.01)；10 mg/mL给药组显著提高线虫抗热应激能力，降低脂褐素积累和ROS水平；同时上调daf-16、sod-3、clt-2、skn-1的mRNA表达量，下调daf-2的mRNA的表达量。结论 白芥子具有良好的体内外抗氧化能力，可能与调控胰岛素/胰岛素样生长因子(insulin like growth factor, IGF)-1信号(insulin/IGF-1 signaling, IIS)通路上的基因表达有关。

Study on antioxidative effect and mechanism of water extracts of white mustard seed based on Caenorhabditis elegans model

ABSTRACT: Objective To study the antioxidant activity of water extract from white mustard seed and explore its mechanism. Methods The antioxidant activity in vitro was evaluated by three methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, hydroxyl radical, and iron ion reducing ability. The effects of water extract from white mustard seed on life span, locomotion ability and reproductive ability of C.elegans were observed using wild type N2 nematode. The effects of oxidative stress, heat stress, lipofuscin and reactive oxygen species (ROS) on the antioxidant capacity of C.elegans were evaluated. Real-time fluorescence quantitative technique was used to determine the expression of genes related to antioxidant and insulin signaling pathway in nematodes treated with water extract from white mustard seed. Results The water extract of white mustard seed had certain DPPH· and hydroxyl radical scavenging ability. The optimal concentration was found to be 10 mg/mL by oxidative stress, and the concentration had no effect on the motility and reproductive ability of C.elegans (P>0.05), and could significantly prolong the mean and median life span of C.elegans (P<0.01). The 10 mg/mL administration group significantly increased the heat stress resistance of nematodes and decreased lipofuscin accumulation and ROS levels. Meanwhile, mRNA expression levels of daf-16, sod-3, clt-2 and skn-1 were up-regulated, while mRNA expression levels of daf-2 were down-regulated. Conclusion White mustard seed has excellent antioxidant ability in vitro and in vivo, and may be related to the expression of genes regulating insulin like growth factor (IGF-1) signaling (IIS) pathway.