论文部分内容阅读
目的观察黄芩苷对Aβ25-35诱导的模型小鼠学习记忆能力的改善作用及对小鼠海马区自噬和自噬相关基因的影响,探讨黄芩苷治疗阿尔茨海默病(AD)的可能机制。方法 C57BL/6小鼠侧脑室注射3μL浓度为3 mmol·L-1的凝聚态Aβ25-35制备AD模型,ip给予黄芩苷25,50和100 mg·kg~(-1),连续给药15 d。通过旷场实验观察小鼠的运动总距离和中央格停留时间,水迷宫定位航行实验观察其潜伏期,空间搜索实验观察原象限停留时间。透射电镜观察海马区自噬小体的生成,Western蛋白印迹法测定中微管结合蛋白1轻链3分子(LC3)和Beclin1的表达。结果脑室注射Aβ25-35可引起小鼠旷场实验运动总距离减少,从(3984±321)cm减少到(2790±306)cm,中央格停留时间由(3.6±1.2)s延长到(8.8±2.9)s,也可使水迷宫实验到达平台总时间由(22.0±1.9)s增加到(38.8±2.2)s;同时观察到海马区早期或晚期自噬泡形成。Western蛋白印迹结果显示,LC3和Beclin1蛋白表达升高(P<0.05)。黄芩苷50和100 mg·kg~(-1)连续给药15 d能延长旷场实验运动总距离,分别为3705±337和(3968±448)cm;中央格停留时间分别缩短为5.6±1.8和(3.9±1.5)s;水迷宫实验到达平台总时间缩短为28.6±1.9和(22.9±1.7)s。透射电镜可见海马区线粒体肿胀,空泡状双层膜结构或者自噬泡形成;LC3和Beclin1蛋白表达明显升高(P<0.01)。结论黄芩苷对AD小鼠的学习记忆损伤有一定的改善作用,作用机制可能与其升高AD小鼠海马区自噬水平有关。
Objective To observe the effect of baicalin on learning and memory abilities induced by Aβ25-35 in mice and its effect on autophagy and autophagy in hippocampus of mice and explore the possible mechanism of baicalin in treating Alzheimer’s disease (AD) . Methods C57BL / 6 mice were injected intracerebroventricularly with 3μL of condensed Aβ25-35 at a concentration of 3 mmol·L-1 to prepare AD model. Baicalin was given ip at doses of 25, 50 and 100 mg · kg -1, d. The total distance of movement and the central grid residence time of the mice were observed through the open-field experiment. The latencies of the mice were observed by the water maze positioning navigation experiment. The original quadrant residence time was observed in the space search experiment. Transmission electron microscopy was used to detect the production of autophagy in the hippocampus. Western blotting was used to detect the expression of microtubule binding protein 1 light chain 3 (LC3) and Beclin1. Results The intracerebroventricular injection of Aβ25-35 caused a decrease in the total distance of open field test from (3984 ± 321) cm to (2790 ± 306) cm in the middle compartment, and prolonged from (3.6 ± 1.2) s to (8.8 ± 2.9) s, the total time for the water maze experiment to reach the platform was also increased from (22.0 ± 1.9) s to (38.8 ± 2.2) s. At the same time, the formation of autophagic vesicles in early or late hippocampus was observed. Western blot results showed that LC3 and Beclin1 protein expression increased (P <0.05). Baicalin 50 and 100 mg · kg -1 could prolong the total distance of open-field experiments for 15 d, which were 3705 ± 337 and 3968 ± 448 cm, respectively. The stay time in the central cell was shortened to 5.6 ± 1.8 And (3.9 ± 1.5) s, respectively. The total time that the water maze test reached the platform was shortened to 28.6 ± 1.9 and (22.9 ± 1.7) s. Transmission electron microscopy revealed mitochondrial swelling, vacuolated bilayer membrane formation or autophagic vacuoles in the hippocampus. The expression of LC3 and Beclin1 protein were significantly increased (P <0.01). Conclusion Baicalin can improve the learning and memory impairment of AD mice, which may be related to the increase of autophagy in hippocampus of AD mice.