人参糖蛋白对小鼠学习和记忆能力的影响

Influence of glycoprotein from Panax ginseng in study and memory abilities in mice

目的：确定人参糖蛋白的基本化学组成,探讨其对东莨菪碱所致小鼠学习和记忆障碍的影响。方法：采用中空纤维超滤设备,对已除去皂苷的人参水提取物进行分离。采用苯酚硫酸法测定总糖含量,Lowry法测定蛋白含量,高效液相色谱法（HPLC）测定人参糖蛋白的纯度和相对分子质量,将人参制备成1-苯基-3-甲基-5-吡唑啉酮（PMP）衍生物后进行单糖组成分析。注射东莨菪碱建立小鼠记忆获得障碍模型,60只小鼠随机分为对照组（正常小鼠）,模型组（训练后腹腔注射氢溴酸东莨菪碱2.5mg·kg-1）,阳性药组（训练前灌胃给药吡拉西坦9 mg·kg-1,30d）,低、中、高剂量人参糖蛋白组（训练前灌胃给药,剂量为7.5、75.0、225.0mg·kg-1）,每组10只。水迷宫实验测定各组小鼠逃避潜伏期;跳台实验测定小鼠跨平台次数。结果：人参糖蛋白总糖质量分数为58.41%,由7种单糖组成,其蛋白质量分数为19.93%,由17种氨基酸组成。人参糖蛋白相对分子质量分布在200-50 000。Morris水迷宫实验,从第3天开始,与模型组比较,高剂量人参糖蛋白组小鼠平均逃避潜伏期明显缩短（P〈0.05）,跨平台次数明显增加（P〈0.01）。在对位训练中,与模型组比较,高剂量人参糖蛋白组小鼠60s内在平台所在象限s的时间明显延长（P〈0.01）,从第2天起,与模型组比较,低、中和高剂量人参糖蛋白组小鼠平均逃避潜伏期明显缩短（P〈0.05）。在跳台实验中,与模型组比较,低、中和高剂量人参糖蛋白组小鼠3min内的错误次数明显减少（P〈0.05）,中剂量人参糖蛋白组小鼠停留在平台上的潜伏期明显延长（P〈0.05）。结论：人参糖蛋白具有提高小鼠记忆能力的作用。

Objective：To identify the basic chemical compositions of panax ginseng glycoprotein,and to discuss its influence in the scopolamine-induced study and memory impairment in the mice.Methods： Hollow fiber ultrafiltration device was used to separate the ginseng aqueous extract which saponin had been removed.The content of total sugar was determined by phenol sulfuric acid method;the content of protein was determined by Lowry method;the purity and relative molecular weight distribution were determined by HPLC;the sugar compositions were analyzed after the preparation of PMP derivatives.The mouse model with acquired memory disorder was established through injection of scopolamine.A total of 60 mice were randomly divided into control group（normol mice）,model group（intraperitoneal administration of scopolamine hydrobromide 2.5 mg·kg-1after training）,positive drug group（intragastric administration of piracetam 9mg·kg-1 for 30 dbefore training）,and low,middle and high doses of Panax ginseng glycoprotein groups（intragastric administration of glycoprotein7.5,75.0,225.0mg·kg-1 respectively for 30 dbefore training）,and there were 10 rats in each group.The escape latency and the number of crossing the platform of the mice were determined by Morris water maze and stepdown test.Results：The total sugar mass fraction of Panax ginseng glycoprotein was 58.41% which was consisted of 7kinds of sugars.The mass fraction of protein was 19.93% which was consisted of 17 kinds of amino acids.The relative molecular weights of Panax ginseng glycoprotein were 200-50 000.The Morris water maze test results showed that from the 3rd day,the average escape latency of mice in high dose of Panax ginseng glycoprotein group was significantly shortened compared with model group（P〈0.05）,and the number of crossing the platform in high dose of Panax ginseng glycoprotein group was significantly more than that in model group（P〈0.01）.The relative position test results showed that the time of spenting in the platform quadrant s of the mice within 60 sin high dose of Panax ginseng glycoprotein group was significantly prolonged compared with model group（P〈0.05）;from the 2day,the average escape latency in different doses of Panax ginseng glycoprotein groups was significantly shortened compared with model group（P〈0.05）.The step-down test results showed that the mice in different doses of Panax ginseng glycoprotein groups made significantly less mistakes within 3 min compared with model group（P〈0.05）;compared with model group,the latent period of landing on the platform of the mice in middle dose of Panax ginseng glycoprotein group was significantly increased（P〈0.05）.Conclusion：Panax ginseng glycoprotein could improve the memory ability of mice.