益智仁对脑老化小鼠认知能力及相关信号蛋白表达的影响

目的 探讨益智仁(Alpinia oxyphylla fructus,AOF)对D-半乳糖致脑老化小鼠学习记忆能力的影响及机制.方法 给小鼠连续皮下注射D-半乳糖,建立脑老化动物模型,用被动回避实验、Morris水迷宫实验检测小鼠学习记忆能力,用Western blot检测海马突触素(Syn)、促细胞分裂原活化蛋白激酶(MAPK)、蛋白激酶C(PKC)的表达水平.结果 ①被动回避实验:脑老化组的潜伏期(119.80±101.80)s]显著短于对照组(279.30±31.64)s](P＜0.01),错误次数(4.4±1.3)次]显著多于对照组(1.8±0.9)次](P＜0.01);而AOF低、中、高剂量组的潜伏期(170.25±68.31)s,(226.31±73.25)s,(263.20±70.55)s]显著长于脑老化组(P＜0.05,P＜0.01),中、高剂量组的错误次数(2.8±1.2)次,(2.3±0.9)次]显著少于脑老化组(P＜0.05,P＜0.01).②水迷宫实验:脑老化组的逃避潜伏期显著长于对照组(P＜0.01),在原先放置平台象限的停留时间显著短于对照组(P＜0.01);而AOF低、中、高剂量组的逃避潜伏期显著短于脑老化组(P＜0.05),中、高剂量组在原先放置平台象限的停留时间显著长于脑老化组(P＜0.05,P＜0.01).③Western blot实验:与对照组相比,脑老化组海马Syn、MAPK、PKC的表达显著降低,而AOF组可显著提高Syn、MAPK、PKC的表达.结论 益智仁可显著改善脑老化小鼠的学习记忆能力,其机制可能与上调海马Syn、MAPK、PKC的表达有关.

Effects of Alpinia oxyphylla fructus on learning-memory and expression of related signal proteins in hippocampus of brain aging mice

Objective To investigate the effects and mechanisms of Alpinia oxyphylla fructus (AOF) on learning and memory in D-galactose induced brain aging mice. Methods The brain aging model was induced by s. c D-galactose. Learning-memory ability was tested by passive avoidance test and Morris water maze test, and the expression of synapsin ( Syn), mitogen-activated protein kinase (MAPK) and protein kinase ( PKC ) in hippocampus were examined by Western blot. Results ① Passive avoidance test:the latency in brain aging group( ( 119.80 ±101.80)s) significantly decreased,and the number of errors (4.4 ± 1.3 ) significantly increased compared with the control group( latency: (279.30 ± 31.64) s; number of errors: ( 1. 8 ±0.9), P＜0. 01 ) ). The latency in low dose, middle dose and high dose AOF group( ( 170.25 ± 68.31 ) s, (226.31 ± 73.25 ) s, (263.20 ± 70.55 ) s) significantly increased, and the number of errors in middle dose and high dose AOF group ( ( 2.8 ± 1.2 ), ( 2.3 ±0. 9 ) ) significantly decreased compared with brain aging group (P ＜ 0. 05, P ＜ 0. 0 1 ). ② Morris water maze test:the escape latency in brain aging group was significantly longer, and the time spent in the original quadrant that previously contained the platform was significantly shorter compared with the control group (P＜0. 01 ). The escape latency in 3 AOF groups was significantly shorter (P＜ 0. 05 ), and the time spent in the original quadrant that previously contained the platform in middle and high dose AOF groups was significantly longer compared with brain aging group (P＜0. 05, P＜0. 01 ). ③ Western blot test:the expression of Syn,MAPK and PKC in hippocampus of brain aging group was significantly weakened than that of the control group. In contrast, the expression of Syn,MAPK, PKC were significantly enhanced in all AOF groups. Conclusion AOF could significantly improve the ability of learning and memory in brain aging mice. Its effects might be related to the increase of the expression of Syn, MAPK and PKC in hippocampus.