纳米脂质体包载辅酶Q10改善血管性痴呆小鼠学习记忆功能的实验研究

目的：研究新型纳米脂质体包载辅酶Q10对血管性痴呆小鼠学习记忆功能的影响及其作用机制。方法：采用薄膜分散法结合超声水合法制备包载辅酶Q10的纳米脂质体并对其进行质量表征。应用双侧颈总动脉夹闭法建立小鼠血管性痴呆（Vascular Dementia，VaD）模型，将实验小鼠随机分成假手术组、模型组、辅酶Q10溶液组及辅酶Q10纳米脂质体组并给于相应的药物治疗。药物干预结束后，应用Morris水迷宫的定位航行及空间探索实验评价各组小鼠的学习及记忆功能，同时采用Western blot结合ELISA分析小鼠海马组织核因子E-2-相关因子-2（Nuclearfactor erythroid-2-related factor-2，Nrf-2）表达及超氧化物歧化酶（Superoxide dismutase，SOD）、丙二醛（Malonaldehyde，MDA）含量探讨辅酶Q10对于血管性痴呆的作用机制。结果：载药纳米脂质体形态圆整、分散性好，粒径小于100 nm，包封率高达89.43%±3.43%。Morris水迷宫实验显示，模型组小鼠的平均逃避潜伏期显著高于假手术组（P<0.05），平台穿越次数及停留时间显著低于假手术组（P<0.05），相比于模型组，辅酶Q10溶液组及纳米脂质体组的平均逃避潜伏期显著降低（P<0.05），平台穿越次数及停留时间显著升高（P<0.05），其中纳米脂质体组行为学改善更加明显，水迷宫指标较单纯溶液组相比有显著性差异（P<0.05）。Western blot及ELISA分析证实，相比于模型组，应用不同形式辅酶Q10治疗干预组小鼠海马组织Nrf-2蛋白表达及SOD含量显著升高（P<0.05），MDA含量显著下降（P<0.05）。结论：应用纳米脂质体包载辅酶Q10能够增加药物的入脑效率，通过调控Nrf-2/ARE途径抑制VaD小鼠脑内的氧化应激损伤，改善VaD动物的学习及认知功能，有望成为治疗VaD的新型药物形式。

Experimental study of coenzyme Q10 loaded nanoliposomes on improving learning and memory function in vascular dementia mice

OBJECTIVE To study the effect of coenzyme Q10 loaded on nano-liposome on the learning and memory function of vascular dementia mice and its mechanism.METHODS The coenzyme Q10 loaded nano-liposomes were prepared by thin film dispersion method combined with ultrasonic hydration method,and their qualities were characterized.Mouse vascular dementia(VaD)model was established by bilateral common carotid artery occlusion.The experimental mice were randomly divided into sham operation group,model group,coenzyme Q10 solution group and coenzyme Q10 nanoliposomes group and corresponding drug treatment were administered.At the end of drug intervention,the learning and memory function of mice in each group were evaluated by the navigation and space exploration test of Morris water maze.The expression of nuclear factor E-2-related factor-2(Nrf-2)and the content of superoxide dismutase(SOD)and malonaldehyde(MDA)in the hippocampus of mice were analyzed by Western blot and ELISA to investigate the mechanism of coenzyme Q10 on vascular dementia.RESULTS Drug-loaded nanoliposomes had rounded morphology and good dispersion.The particle size of nanoliposomes was less than 100 nm,and the encapsulation efficiency was as high as(87.67±1.12)%.Morris water maze test showed that the average escape latency of mouse in the model group was significantly longer than that in the sham-operated group(P<0.05).The number of platform crossing and residence time were significantly lower than those in the sham-operated group(P<0.05).Compared with the model group,the average escape latency of coenzyme Q10 solution group and nanoliposome group was significantly shorter(P<0.05)and the number of platform crossing and residence time was significantly higher(P<0.05).In addition,coenzyme Q10 nano-liposomes group showed more significant improvement in the index of water maze compared with drug solution group(P<0.05).Western blot and ELISA analysis confirmed that the expression of Nrf-2 protein and SOD in hippocampus tissue of mice treated with different forms of coenzyme Q10 were significantly increased(P<0.05)compared with model group,while the content of MDA was significantly decreased(P<0.05).CONCLUSION The application of nano-liposomes containing coenzyme Q10 can increase the efficiency of drug delivery into the brain which will inhibit the oxidative stress injury in the brain of VaD mouse by regulating the nrf-2/ARE pathway.The coenzyme Q10 loaded nano-liposomes can improve the learning and cognitive functions of VaD animals,which is expected to become a new drug form for the treatment of VaD.