铁皮石斛多糖调控线虫寿命及抗氧化作用的研究

Study on the lifespan and antioxidant effects of Dendrobium officinale polysaccharides on Caenorhabditis elegans

中文关键词:  秀丽隐杆线虫  铁皮石斛多糖  衰老  抗氧化

英文关键词:Caenorhabditis elegans  Dendrobium officinale polysaccharides  aging  antioxidant

中文摘要:

      目的 基于秀丽隐杆线虫自然衰老模型, 探讨铁皮石斛多糖(Dendrobium officinale polysaccharides, DOP)抗衰老作用及其机制。方法 将秀丽隐杆线虫野生型N2随机分为对照组和铁皮石斛多糖组(低、中、高), 观察铁皮石斛多糖对线虫N2寿命、运动能力和咽泵能力的影响; 通过氧化应激、抗氧化酶试剂盒以及活性氧评估铁皮石斛多糖对N2线虫抗氧化能力的影响。基于skn-1基因缺陷型突变株(EU1)线虫及带有荧光标记的转基因线虫CL2166分析铁皮石斛多糖延长健康寿限的可能作用途径; 采用实时荧光定量聚合酶链反应技术测定铁皮石斛多糖作用下线虫抗氧化、胰岛素信号途径相关基因转录水平。结果 铁皮石斛多糖中剂量组(250 μg/mL)可显著延长线虫N2的寿命, 平均延寿率达12.73%, 可显著提高运动、咽泵、抗氧化应激能力; 显著提高过氧化氢酶(catalase, CAT)、超氧化物歧化酶(superoxide disumutase, SOD)活性和谷胱甘肽(glutathione, GSH)含量, 降低活性氧(reactive oxygen species, ROS)水平和丙二醛(malondialdehyde, MDA)含量; 铁皮石斛多糖干预处理对skn-1基因缺陷线虫的延寿效果缺失; 但能够增强CL2166线虫的荧光强度; 同时上调sod-5、sod-3、ctl-1、ctl-2、daf-16和skn-1基因的表达水平, 下调daf-2基因的表达水平。结论 铁皮石斛多糖可能通过激活Nrf2/SKN-1和DAF-16途径拮抗氧化应激从而延缓线虫衰老。

英文摘要:

      Objective To investigate the anti-aging effect and mechanism of Dendrobium candidum polysaccharides (DOP) based on the natural aging model of Caenorhabditis elegans. Methods Wild type of Caenorhabditis elegans N2 were randomly divided into control group and Dendrobium officinale polysaccharides group (low, medium and high) to observe the effects of Dendrobium officinale polysaccharides on lifespan, exercise capacity and pharyngeal pump capacity of N2 nematodes; the effects of Dendrobium officinale polysaccharide on the antioxidant capacities of N2 nematodes were evaluated by oxidative stress, antioxidant enzyme kits and reactive oxygen species. Based on skn-1 defective mutant (EU1) and fluorescent labeled transgenic nematode CL2166, the possible mechanism of Dendrobium officinale polysaccharide in prolonging healthy lifespan was analyzed; the transcription levels of genes related to antioxidant and insulin signaling pathways in nematodes under the action of Dendrobium officinale polysaccharides were determined by real-time fluorescence quantitative polymerase chain reaction. Results The middle-dose group of Dendrobium officinale polysaccharides (250 μg/mL) could significantly prolong the lifespan of N2 nematodes, with an average lifespan extension rate of 12.73%, and significantly improve the ability of exercise, pharyngeal pump, and anti-oxidative stress, significantly increase catalase (CAT), superoxide dismutase (SOD) activities and glutathione (GSH) content, decrease reactive oxygen species (ROS) levels and malondialdehyde (MDA) content. The life-extending effect of Dendrobium officinale polysaccharide treatment on skn-1 gene-deficient nematodes was missing; the fluorescence intensity of CL2166 nematodes was enhanced. At the same time, the expression levels of sod-5, sod-3, ctl-1, ctl-2, daf-16 and skn-1 genes were up-regulated, and the expression level of daf-2 gene was down-regulated. Conclusion Dendrobium officinale polysaccharides may antagonize oxidative stress by activating Nrf2/SKN-1 and DAF-16 pathways, thereby delaying nematode senescence.