清开灵对快速老化痴呆小鼠学习记忆能力的影响及作用机制研究

Effect and Mechanism of Action of Qingkailing on Learning and Memory Capacity of SAMP8 Mouse

目的探讨清开灵对快速老化痴呆小鼠(senescence accelerated mouse-prone/8,SAMP8)学习记忆能力、全脑神经递质及磷脂酰肌醇3激酶激活的丝氨酸/苏氨酸蛋白激酶B磷酸化(phosphatidylinositol 3-kinase/protein kinase B,PI3K/AKT)信号通路的影响。方法将SAMP8老化鼠随机分为模型组、清开灵组[1.3mL/(kg·d)]及安理申组[0.58 mg/(kg·d)],治疗90天;抗快速老化亚系小鼠(senescence acceleratedmouse-resistance/1,SAMR1)作为对照组。采用水迷宫方法检测小鼠学习记忆能力,以高效液相电化学法检测小鼠全脑乙酰胆碱(ACh)及单胺类神经递质含量,蛋白质印迹法(Western-blot)测定脑Gab1(Grb2-associatedbinder-1)、AKT、473位点丝氨酸磷酸化蛋白激酶B(phospho-serine/threonine protein kinase B,pAKT473)的蛋白表达。结果与对照组SAMR1鼠比较,模型组SAMP8小鼠在隐平台试验和反向试验第3天潜伏期显著升高(P<0.05,P<0.01),ACh、5-羟色胺(5-HT)水平显著降低(P<0.01,P<0.05),Gab1蛋白表达水平显著降低(P<0.01)。给药后,清开灵组小鼠在第2～5天隐平台试验和反向试验中潜伏期较模型组显著降低(P<0.05),ACh、5-HT含量明显升高(P<0.05),Gab1蛋白表达水平显著增加(P<0.01),AKT蛋白磷酸化水平显著增加(P<0.05)。结论清开灵能改善AD模型小鼠的学习记忆能力,这一作用可能与其提高脑内ACh、5-HT的水平,激活PI3K/AKT通路有关。

Objective To investigate the influence of Qingkailing （QKL） on leaming and memory abilities, global neurotransmitter and phosphatidylinositol 3-kinase/protein kinase B （PI3K/AKT） signaling pathway of senescence accelerated mouse-prone/8 （SAMP8） mice with Alzheimer＇s dementia （AD）. Methods SAMP mice were modeled and divided into the model group, the QKL group and the doneppezil hydrochloride group, all treated for 90 days. And a control group was set up with senescence accelerated mouse-resistance/1 （SAMR1） mice. Morris water maze was used to test the learning and memory abilities of mice; contents of acetylcholine （Ach） and monoamine neurotransmitters in brain were measured by HPLC; levels of Grb2-associated binder-1 （Gab1）, AKT and phospho-serine/threonine protein kinase B （PAKT473） were evaluated by Western-blot. Results Compared with the control group, in the model group, the average escape latency detected by hidden platform trial and reverse frial on the 3rd day was higher （ P 〈 0.01 ） ; levels of Ach, 5-hydroxytryptamine （5-HT） and Gab1 were lower （P〈0. 01, P〈0. 05 and P〈0. 01 ）, respectively. As compared with the model group, the escape latency （within the 2nd to 5th day） decreased （P 〈 0.01 ）, levels of Ach and 5-HT increased （P 〈 0.05）, and Gab1 protein expression increased （ P 〈0.01 ） in the QKL treated group after treatment, in addition, the level of phosphorylated AKT protein significantly increased （ P 〈0.05）. Conclusion QKL could improve the learning and memory ability of AD model mice, which is probably related to its function in increasing cerebral Ach, 5-HTand activating PI3K/AKT pathway.