四物汤对糖尿病小鼠学习记忆能力的影响

Effects of Siwu Decoction on Learning and Memory Ability in Mice with Diabetes Mellitus

目的观察四物汤对尾静脉注射链脲佐菌素诱导的糖尿病小鼠学习记忆能力的影响,探讨其改善学习记忆损伤的作用机制。方法55只ICR小鼠随机分为空白对照组、模型组、四物汤低剂量组和四物汤高剂量组,除空白对照组外,采用尾静脉注射链脲佐菌素(180 mg/kg)建立糖尿病小鼠模型。造模成功后开始给药,四物汤低剂量组给药剂量2.5 g/kg,四物汤高剂量组给药剂量5 g/kg,空白对照组和模型组灌胃等体积蒸馏水,连续40 d。给药第7、21、35、40日检测小鼠体质量和血糖,第40日进行糖耐量实验;Morris水迷宫实验评价小鼠学习记忆能力;ELISA检测海马组织脑源性神经营养因子(BDNF)含量;HE染色和尼氏染色观察海马CA1区神经元形态;Western blot检测海马组织突触相关蛋白PSD95、Shank3、NR1和NR2B表达。结果与空白对照组比较,模型组小鼠给药第21、35、40日血糖明显升高,血糖曲线下面积(AUC)明显增加(P<0.001),Morris水迷宫实验逃避潜伏期明显延长(P<0.05),海马组织BDNF含量有降低趋势,但差异无计学意义(P>0.05),海马CA1区神经元核固缩,细胞排列散乱、间隙增大,尼氏体小且数量少,海马组织PSD95、Shank3、NR1和NR2B表达明显降低(P<0.01,P<0.001);与模型组比较,四物汤低剂量组给药第35、40日及四物汤高剂量组给药第21、35日血糖明显降低(P<0.05,P<0.001),四物汤低剂量组AUC明显降低(P<0.05),2组Morris水迷宫实验逃避潜伏期明显缩短(P<0.001,P<0.01),海马组织BDNF含量有升高趋势,但差异无统计学意义(P>0.05),海马CA1区神经损伤改善,细胞排列紧密,尼氏体数量增加,四物汤低剂量组NR1和NR2B蛋白表达明显升高(P<0.01,P<0.05),四物汤高剂量组Shank3、NR1和NR2B蛋白表达明显升高(P<0.05,P<0.01),PSD95蛋白表达有升高趋势,但差异无统计学意义(P>0.05)。结论四物汤可改善链脲佐菌素诱导的糖尿病小鼠学习记忆损伤,其作用机制与提高海马组织突触相关蛋白Shank3、NR1和NR2B表达,保护突触功能有关。

Objective To observe the effects of Siwu Decoction on learning and memory ability of diabetes mellitus mice induced by tail intravenous injection of streptozotocin;To explore its mechanism of improving learning and memory impairment.Methods Totally 55 ICR mice were randomly divided into blank control group,model group,Siwu Decoction low-and high-dosage groups.Except the blank control group,diabetes mellitus mice model was established by injecting 180 mg/kg streptozotocin into tail vein.After model was successfully built,Siwu Decoction low-and high-dosage groups were treated with 2.5 g/kg and 5 g/kg Siwu Decoction by gavage respectively,and the blank control group and model group were treated with the same amount of distilled water,for 40 days.Body mass and blood glucose were monitored on the 7th,21st,35th and 40th day of administration,and glucose tolerance test was performed on the 40th day;Morris water maze test was conducted to test the learning and memory ability;ELISA was used to detect brain-derived neurotrophic factor(BDNF)content in hippocampal tissue;neuronal morphology in hippocampal CA1 region was observed by HE staining and Nissl staining;Western blot was used to detect the expression of synapse-related proteins PSD95,Shank3,NR1 and NR2B in hippocampal tissue.Results Compared with the blank control group,the blood glucose of model group increased on the 21st,35th and 40th day,and AUC of blood glucose increased significantly(P<0.001),escape latency of Morris water maze test extended significantly(P<0.05),the content of BDNF in hippocampal tissue reduced,but without statistical significance(P>0.05),the neurons in CA1 region of hippocampus showed nuclear shrinkage,with scattered cells and enlarged intercellular space,and Nissl bodies were small and few,the expression of PSD95,Shank3,NR1 and NR2B protein decreased significantly(P<0.01,P<0.001).Compared with the model group,the blood glucose of Siwu Decoction low dosage group on the 35th,40th day and Siwu Decoction high-dosage group on the 21st,35th day decreased significantly(P<0.05,P<0.001),and AUC of blood glucose in Siwu Decoction low-dosage group significantly decreased(P<0.05),the escape latency of Morris water maze test in both group significantly shortened(P<0.001,P<0.01),the content of BDNF in hippocampal tissue increased,but without statistical significance(P>0.05),neural damage in CA1 region of hippocampus improved,with tightly arranged cells,and an increase in the number of Nissl bodies,the expression of NR1 and NR2B protein in Siwu Decoction low-dosage group increased(P<0.01,P<0.05),the protein expressions of Shank3,NR1 and NR2B in Siwu Decoction high-dosage group increased(P<0.05,P<0.01),PSD95 protein expression showed an upward trend,but without statistical significance(P>0.05).Conclusion Siwu Decoction can improve the learning and memory impairment in streptozotocin-induced diabetes mellitus mice,and the mechanism may be related to the improvement of synapse-associated proteins of Shank3,NR1 and NR2B expression in hippocampus,and the protection of synaptic function.