茶叶中表没食子儿茶素没食子酸酯（EGCG）抗衰老的低促效应研究

发布时间：2018-03-04 04:08

本文选题：茶叶　切入点：EGCG　出处：《湖南农业大学》2015年博士论文　论文类型：学位论文

【摘要】：表没食子儿茶素没食子酸酯(Epigallocatechin-3-gallate, EGCG)是绿茶中主要的儿茶素类物质,具有抗氧化、抗过敏、抗炎症、抗辐射和降血脂等一系列生物活性。EGCG对活体寿命的影响研究较少且存在争议。本文在前人已有研究基础上,进一步探讨EGCG对秀丽线虫(Caenorhabditis elegans)寿命的调节作用及其潜在作用机制。主要研究结果如下：(1)通过EGCG干预野生型秀丽线虫N2整个成虫期的寿命试验发现,在0-300 μM浓度范围内与秀丽线虫平均寿命正相关；在300-500 μM范围内不显著影响秀丽线虫平均寿命；在浓度超过500μM时与秀丽线虫的平均寿命负相关。不同食物结构(活菌、死菌和EGCG预处理大肠杆菌)寿命试验发现,EGCG调节秀丽线虫寿命与其抗菌性无关；同时添加EGCG和过氧化物酶(CAT)进行寿命试验发现,EGCG调节秀丽线虫寿命与其在NGM中自动氧化生成的H202无关。(2)通过EGCG限时干预野生型秀丽线虫N2成虫早期和中期(6 d)、干预不同年龄阶段秀丽线虫(成虫第6、12和18d开始干预)和干预秀丽线虫整个成虫期对其衰老相关功能衰退的影响发现,EGCG调节秀丽线虫寿命的主要作用时期是成虫早中期。通过去除NGM中蛋白胨进行野生型秀丽线虫N2寿命试验发现,EGCG对秀丽线虫N2寿命的影响程度较正常培养条件下小。通过DA465 (eat-2缺失)突变体寿命试验发现,200和1000 μM对DA465突变体寿命的影响较其对N2的影响要小。(3)EGCG干预野生型秀丽线虫N248 h后进行应激试验发现,在不同应激环境下,不同EGCG浓度产生不同效果,最优浓度并不一致。EGCG调节秀丽线虫热应激抵抗的剂量效应与调节寿命一致。200 μM EGCG限时干预(6 d)可帮助秀丽线虫N2抵御1000μM EGCG引起的寿命损伤。(4) EGCG不影响秀丽线虫N2生殖和幼虫发育。400和1000 μM EGCG干预秀丽线虫幼虫期显著缩短其体长。EGCG干预秀丽线虫N2幼虫期并不影响Fl、F2和F6代(连续干预5代)成虫寿命。(5) EGCG(200和1000μM)干预降低秀丽线虫ATP水平和TG含量,并短期提升ROS含量,激活抗氧化防御系统清除ROS。同时添加EGCG和抗氧化剂N-乙酰半胱氨酸(NAC)或叔丁基-4-羟基茴香醚(BHA)进行寿命试验发现,EGCG(200和1000μM)不再显著影响野生型秀丽线虫N2寿命。200 μM EGCG提升秀丽线虫NAD+水平,1000 μM EGCG降低秀丽线虫NAD+水平。200 μMEGCG延长秀丽线虫寿命与AAK-2、 SIR2.1、PRDX-2、PMK-1、DAF-16、SKN-1以及线粒体电子传递链相关,与HIF-1、 SOD-3和胰岛素及类胰岛素信号通路无关。另外,1000 μM EGCG缩短秀丽线虫亦与SIR2.1相关。通过测定mtDNA与nDNA比例发现,200 μM EGCG能有效促进线粒体生物合成。通过绿色荧光蛋白融合表达hsp-6和hsp-60转基因品系的绿色荧光表达及qPCR试验发现,EGCG并未诱导线粒体未折叠蛋白质响应。
[Abstract]:Epigallocatechin-3-gallateEpigallocatechin-3-gallateEpigallocatechin-3-gallateEpigallocatechin-3-gallateEpigallocatechin-3-gallateEpigallocatechin-3-gallateEpigallocatechin-3-gallateEpigallocatechin-3-gallate (. A series of biological activities, such as anti-radiation and hypolipidemia, have little or no research on the effects of EGCG on life span in vivo. The effects of EGCG on the life span of Caenorhabditis eleans were further studied. The main results were as follows: 1) the results of EGCG intervention on the life span of wild-type nematode N _ 2 in the whole adult stage were as follows:. In the range of 0-300 渭 M, there was a positive correlation with the average life span of the nematode, but not in the range of 300-500 渭 M, but negative correlation with the average life span of the nematode when the concentration was above 500 渭 M. different food structure (living bacteria, The life test of dead bacteria and Escherichia coli pretreated with EGCG showed that there was no relationship between the life span of EGCG-regulated nematode and its antimicrobial activity. EGCG and peroxidase (EGCG) were added in the longevity test. It was found that EGCG-regulated nematode longevity was independent of H202, which was produced automatically in NGM.) EGCG limited time was used to intervene in the early and middle stage of N _ 2 adult nematode wild-type nematode N _ 2 for 6 days. The effects of different age stages on senescence related function of nematodes (beginning intervention on the 12th and 18th days of adult worms) and the whole adult stage of C. elegans showed that EGCG mainly regulates the longevity of C. elegans in the early stage of adults. In the middle stage, by removing peptone from NGM, the N _ 2 longevity of wild type nematode nematode was tested. It was found that the effect of EGCG on N _ 2 longevity of nematode was less than that under normal culture condition. The effect of 1 000 渭 M on the lifespan of DA465 mutant was less than that on N2. The stress test showed that 1 000 渭 M treated wild-type nematode N248 h later. Under different stress conditions, different concentrations of EGCG produced different effects. The dose effect of EGCG regulating the heat stress resistance of nematode nematode is the same as that of the control life. 200 渭 M EGCG for 6 days) can help N 2 to resist 1 000 渭 M EGCG induced life damage. 4) EGCG does not affect N 2 of nematode. Reproductive and larval development. 400 and 1 000 渭 M EGCG intervention significantly shortened the larval stage of nematode nematode. EGCG did not affect the lifespan of F 2 and F 6 generations (5 successive generations) EGCG(200 and 1 000 渭 M). ATP level and TG content, And increase the ROS content in a short time, Activation of antioxidant defense system to remove ros.An addition of EGCG and the antioxidant N-acetylcysteine or tert-#china_person0# -4- hydroxyanisole (BHA) were used to test the life of wild nematode nematode. It was found that EGCG 200 and 1000 渭 M) no longer significantly affected the N2 life span of wild nematode nematode. 200 渭 M. The increase of NAD level by EGCG and the decrease of NAD level by 200 渭 MEGCG were associated with AAK-2, SIR2.1% PRDX-2 PMK-1, DAF-16SKN-1 and mitochondrial electron transport chain. It was not related to HIF-1, SOD-3, insulin and insulin-like signal transduction pathway. The other 1 000 渭 M EGCG shortening nematode was also associated with SIR2.1. It was found that the ratio of mtDNA to nDNA could effectively promote mitochondrial biosynthesis. The green fluorescence expression of hsp-6 and hsp-60 transgenic lines expressed by white fusion and qPCR test showed that EGCG did not induce the response of mitochondrial unfolded protein.
【学位授予单位】：湖南农业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R151

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