V11抗阿尔茨海默病作用

发布时间：2019-03-22 08:02

【摘要】：共生真菌在与宿主之间协同进化的过程中,形成了物种丰富,数量庞大的资源库,其次生代谢产物特有的化学结构复杂性和生物活性多样性,奠定了从中发现活性先导物进而研发创新药物的成功几率。随着全球人口的老龄化,阿尔茨海默病的发病率也在快速上升,由于阿尔茨海默病病因的复杂多样,传统乙酰胆碱酯酶抑制剂仅能在一定程度上缓解中、轻度阿尔茨海默病患者的症状,并不能终止和逆转阿尔茨海默病的病情进展,因此,研究新型多靶向、安全高效的抗阿尔茨海默病药物是当代社会对改善健康状况、提高生活质量的急切需求。本文研究了一种从藤本植物红花青藤(I. rhodantha)内生真菌Phomopsis sp.S12次级代谢产物中分离得到新型二萜类化合物V11的抗阿尔茨海默病生物活性,主要包括以下内容：第一章：综述阿尔茨海默病发病机制和药物治疗研究进展。第二章：对V11的AChE抑制活性进行研究。通过Ellman比色法检测了其在体外对AChE和BuChE的抑制活性,其中对AChE的IC50接近阳性对照石杉碱甲。萜类结构使得V11具有良好的脂溶性,易于通过血脑屏障,并在脑组织中保持较长时间,以发挥作用。通过LC-MS检测不同时间点V11在脑组织中分布,发现其与脑组织内AChE活力呈现一定相关性。对Aβ1-42双侧海马注射造模小鼠给药后进行水迷宫实验,证明V11具有改善AD模型动物学习记忆能力的作用,其显著的AChE抑制活性可能是改善学习记忆能力的直接原因。第三章：对V11的免疫抑制活性及调节相关通路的研究。利用DCFH-DA作为荧光探针检测Aβ1-42刺激SH-SY5Y细胞内活性氧水平,发现经过V11预处理的细胞活性氧水平低于未经处理的细胞；通过Real time PCR检测了体内Aβ142诱导炎症因子(IL-6, TNF-α和IL-1α) mRNA表达被抑制,且呈现量效依赖关系。通过Western blot检测了V11抑制Toll样受体-4表达,进一步抑制NF-κB活化,通过下调Bax蛋白表达抑制细胞凋亡,上调cAMP反应结合原件(CREB)磷酸化水平,从而促进长时程记忆的形成。此外,本文初步研究了V11在抑制Aβ1-42向聚集态过程中发挥的作用,提示其可能在缓解阿尔茨海默病病程中发挥作用。
[Abstract]:In the process of co-evolution between symbiotic fungi and host, they form abundant species and huge number of resources, and their secondary metabolites have unique chemical structure complexity and biological activity diversity. It establishes the probability of discovery of active precursors and development of innovative drugs. With the aging of the global population, the incidence of Alzheimer's disease is also rising rapidly. Due to the complexity and variety of the causes of Alzheimer's disease, traditional acetylcholinesterase inhibitors can only alleviate the disease to a certain extent. The symptoms of mild Alzheimer's disease do not stop and reverse the progression of Alzheimer's disease, so the study of new, multi-targeted, safe and efficient anti-Alzheimer's disease drugs is a modern society's contribution to improving health. An urgent need to improve the quality of life. A novel diterpenoid, V11, was isolated from the secondary metabolites of (I. rhodantha) endophytic fungus Phomopsis sp.S12 in lianas, and its bioactivity against Alzheimer's disease was studied in this paper. The main contents are as follows: chapter 1: review the pathogenesis and drug therapy of Alzheimer's disease. Chapter 2: the AChE inhibitory activity of V11 was studied. Its inhibitory activity to AChE and BuChE in vitro was detected by Ellman colorimetry, among which the IC50 against AChE was close to that of Huperzine A. Terpenoid structure makes V11 have good fat solubility, easy to pass through the blood-brain barrier, and keep it in the brain for a long time to play a role. The distribution of V11 in brain tissue was detected by LC-MS at different time points. It was found that V11 was correlated with the activity of AChE in brain tissue. The water maze test of A 尾 1 / 42 mice injected bilaterally into hippocampus showed that V11 could improve the learning and memory ability of AD model animals, and the obvious inhibitory activity of AChE might be the direct cause of improving learning and memory ability. Chapter 3: study on the immunosuppressive activity of V11 and the regulation of related pathways. DCFH-DA was used as fluorescence probe to detect the level of reactive oxygen species (Ros) in SH-SY5Y cells stimulated by A尾 1-42. It was found that the level of Ros in cells pretreated with V11 was lower than that in untreated cells. The mRNA expression of inflammatory factors (IL-6, TNF- 伪 and IL-1 伪) induced by A 尾 142 was detected by Real time PCR in a dose-dependent manner. V11 inhibited the expression of Toll-like receptor-4 by Western blot, further inhibited the activation of NF- 魏 B, inhibited cell apoptosis by down-regulating the expression of Bax protein, and upregulated the phosphorylation level of cAMP-binding (CREB), thus promoting the formation of long-term memory. In addition, the role of V11 in inhibiting the aggregation of A 尾 1-42 was preliminarily studied, suggesting that V11 may play a role in relieving the course of Alzheimer's disease.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R96

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