益智仁水提取物对东莨菪碱所致记忆获得障碍大鼠的干预效应

Interventional effect of the water extract of Alpinia oxyphylla Miq. fruit on scopolamine-induced learning and memory impairements in rats

目的:观察益智仁水提取物对东莨菪碱所致大鼠记忆获得障碍的改善效果。方法:实验于2005-03/04在大连大学医学院动物室和神经科学实验室完成。选择健康成年Sprague-Dawley纯种大鼠50只,在温度为(22±3)℃的环境中适应两天后,随机数字表法分成对照组、模型组、益智仁低剂量组(120mg/kg)、益智仁中剂量组(240mg/kg)、益智仁高剂量组(480mg/kg),每组10只,雌雄各半。益智仁低、中、高剂量组,每天分别灌胃120mg/kg、240mg/kg、480mg/kg益智仁水提取物,对照组和模型组灌胃等量的生理盐水,连续给药21d。末次给药后1h采用Y迷宫进行学习记忆行为训练,训练前15min模型组及益智仁低、中、高剂量组腹腔注射东莨菪碱1mg/kg,对照组腹腔注射等体积生理盐水,每只动物每天训练20次,连续训练7d,以正确反应率达到90%作为学会的标准,并记录各组的训练次数(达到学会标准所需的次数)。行为实验结束后,立即麻醉后断头处死大鼠,在冰块上快速分离双侧海马,准确称重,按重量体积比加9倍生理盐水制成10%脑组织匀浆,2000r/min离心10min,采用乙酰胆碱酯酶测定试剂盒测定乙酰胆碱酯酶活性,采用双缩脲蛋白测定试剂盒测定海马脑蛋白含量,主要观察Y迷宫行为实验各组大鼠达标所需的训练次数、海马乙酰胆碱酯酶活力及海马脑蛋白含量。数据以x±s表示,组间比较采用t检验。结果:各实验组大鼠全部进入结果分析。①益智仁水提取物对东莨菪碱所致记忆障碍大鼠学习记忆能力的影响:益智仁低、中、高剂量组达标所需训练次数显著低于模型组(58.6±15.0,55.0±13.8,67.6±8.7)次,(136.3±16.8)次,(P<0.01),模型组大鼠达标所需训练次数显著高于对照组(P<0.01)。②益智仁水提取物对东莨菪碱所致记忆障碍大鼠海马乙酰胆碱酯酶活力的影响:益智仁低剂量组和中剂量组海马乙酰胆碱酯酶活力显著低于模型组(28.5±9.3,22.2±7.2)μkat/g,(47.2±18.8)μkat/g,(P<0.05);模型组海马乙酰胆碱酯酶活力显著高于对照组(P<0.05)。③益智仁水提取物对东莨菪碱所致记忆障碍大鼠海马脑蛋白含量的影响:与模型组相比,益智仁低剂量组、中剂量组脑蛋白含量显著增高(P<0.05);与对照组相比,模型组大鼠海马脑蛋白含量显著降低(P<0.05)。结论:益智仁水提取物抑制乙酰胆碱酯酶活性,减少乙酰胆碱分解,提高海马脑蛋白含量,对东莨菪碱所致记忆获得障碍具有显著的改善作用。

AIM： To observe the effects of the water extract of Alpinia oxyphylla Miq. fruit （AOF） in ameliorating scopolamine-induced learning and memory lmpairments m rats. METHODS： The experiment was carried out in the animal room and neuroscience laboratory, Medical College of Dalian University between March and April 2005. Fifty healthy adult pure Sprague-Dawley rats were used in the experiment. After 2-day adaptation in the environment of （22±3） ℃, the rats were divided into 5 groups （10 rats in each group, half male and half female） by means of random number table： control group, model group, AOF low, middle and high dosage groups （120, 240 and 480 mg/kg respectively）.The rats in the AOF low, middle and high dosage groups were treated with gastric perfusion of the AOF water extract of 120 mg/kg, 240 mg/kg, 480 mg/kg respectively every day, and those in the control group and model group were given gastric perfusion of saline of the same volume for 21 continuous days. At 1 hour after the last administration, the rats received training of learning and memory behavior by using Y-maze. At 15 minutes before training, rats in the model group and AOF low, middle and high dosage groups were given intraperitoneal injection of scopolamine （1 mg/kg）, and those in the control group were injected with saline of the same volume. Each rat was trained for 20 times every day for 7 continuous days; the standard of “can do” was the right reaction rate reached 90%, and the number of trainings （needed by reaching the standard of“can do”） in each group was recorded. After the experiment, the rats were killed immediately after anesthesia by cutting down the heads, and then bilateral hippocampi were rapidly isolated on the ice cubes and weighed accurately, 10% brain tissue homogenate was prepared by saline of 9 time according to ratio of mass and volume, centrifugated for 10 minutes （2 000 rounds per minute）. The activity of acetylcholinesterase was detected with acetylcholinesterase kit, the content of hippocampal protein was determined with biuret reaction kit. The number of trainings needed byreaching the standard of “can do”in Y-maze behavior test, activity of acetylcholinesterase and content of protein in hippocampi were observed. The data were expressed as mean＋standard deviation, and the t test was used for intergroup comparison. RESULTS： All the rats in the groups were involved in the analysis of results. ① Influence of AOF water extrac.t on the ability of learning and memory in rats with scopolamine-induced memory disorders： The needed training number was significantly fewer in the AOF low, middle and high dosage groups than in the model group [（58.6±15.0）, （55.0±13.8）, （67.6±8.7） times; （136.3±16.8） times, P 〈 0.01], but significantly more in the model group than in the control group （P 〈 0.01）. ② Influence of AOF water extract on the activity of acetylcholinesterase in hippocampi of rats with scopolamine-induced memory disorders： It was significantly lower in the AOF low and middle dosage groups than in the model group [（28.5±9.3）, （22.2±7.2）, （47.2±18.8）μkat/g, P 〈 0.05], but significantly higher in the model group than in the control group （P 〈 0.05）. ③ Influence of AOF water extract on the content of protein in hippocampi of rats with scopolamine-induced memory disorders： It was significantly higher in the AOF low and middle dosage groups than in the model group [（38.3±9.4）, （37.0±10.8）, （23.9±5.9） g/L, P 〈 0.05], but significantly lower in the model group than in the control group （P 〈 0.05）. CONCLUSION： AOF water extract can inhibit the activity of acetylcholinesterase, reduce the disintegration of acetylcholine, and increase the content of protein in hippocampi, sO it plays a role in ameliorating scopolamine-induced learning and memory,impairments.