黄精有效部位对老年痴呆小鼠学习记忆障碍的影响及作用机制初探

Study on the Effects and Mechanisms of Effective Extracts of Huangjing(Polygonati Rhizoma)on Learning and Memory Impairment in Mice with Alzheirmer's Disease

目的探讨黄精各有效部位对老年痴呆(alzheirmer's disease,AD)小鼠学习记忆障碍的治疗效果和治疗机制。方法采用D-半乳糖和东莨菪碱造AD小鼠模型,分别用乙酸乙酯、正丁醇、二氯甲烷萃取黄精提取液并进行灌胃治疗。6周灌胃治疗结束后用水迷宫实验测试小鼠学习记忆能力,试剂盒检测小鼠脑组织SOD、GSH-Px活性、MDA水平以及AChE和ChAT的变化。结果AD小鼠造模成功,黄精各给药组不同程度降低逃避潜伏期时间,且各个高剂量组效果好于相应的低剂量组,提高在平台所在象限时间和跨越平台次数且呈剂量依赖性。黄精各给药组不同程度升高了脑内SOD、GSH活性,降低MDA水平,乙酸乙酯高剂量组极显著地提高了SOD活性,二氯甲烷高剂量组、正丁醇高剂量组和乙酸乙酯高剂量组均能显著增高GSH含量,高剂量组(正丁醇除外)和阳性组MDA水平均显著降低;黄精各给药组也提高ChAT活性和降低AChE表达,且随剂量增加药效越明显。结论黄精各有效部位能提高AD小鼠的学习记忆能力,抗氧化水平,并修复胆碱功能损伤,且呈剂量依赖性。

Objective To investigate the effects of different extracts of Huangjing(Polygonati Rhizoma)on the ameliorative effects of learning and memory impairment in mice with Alzheimer's disease(AD)and analyse the therapeutic mechanisms.Methods D-galactose and scopolamine were used to create AD model mice,and ethyl acetate,N-butanol,dichloromethane were used as solvent extraction solution which extracted relevant ingredients for treatment.After 6 weeks of treatment,Morris water maze experiment was used to test the learning and memory ability of mice.Meanwhile,following the behavioral tests,the biochemical analysis for SOD and GSH activities,MDA levels,AChE and ChAT activities in brain tissue of mice were measured.Results The AD mice were successfully modeled.In the Morris water maze experiment,compared with the model group,the escape latency time was reduced in each administration group,and the effect of each high dose group was better than that of the corresponding low dose group,and the time mice swam in the quadrant where the platform was located and the number of mice crossing the platform were increased.And the activities of SOD and GSH were increased,and the level of MDA was decreased in all of the groups treated with Huangjing(Polygonati Rhizoma).Ethyl acetate high dose group significantly increased the activity of SOD,dichloromethane high dose group,N-butanol high dose group and ethyl acetate high dose group significantly increased the content of GSH,and the level of MDA was significantly decreased in high dose group(except of N-butanol)and positive group.ChAT and AChE activities,which regulat ACh metabolism,ChAT activity was found increased,while the expression of AChE was decreased.And the effect of the drugs increased with the increase of dosage.Conclusion The results reveal that different extracts of Huangjing(Polygonati Rhizoma)could significantly improve the learning and memory ability,increase the antioxidant levels,and alleviate the choline function damage of AD mice,and the effects are dose-dependent.