Effects Of Different Therapeutic Principles And Prescriptions On Learning And Memory Disorders And Cytokine Network In Senescence-Accelerated Mice

ObjectiveTo explore the effects of various traditional Chinese medicinalprescriptions on the age-related deterioration of learning and memory inSAM and investigate if such changes are related the expression ofcytokines(IL-2,IL-6)and cytokine net-works.MethodsEighty four 7-month-old male senescence-accelerated mice pronestrain/8(SAMP8) were assigned to the LW prescription group,the Sijunziprescription group,the Guipi prescription group,the DSS prescriptiongroup,the Piracetam prescription group and the model group by blockrandomization. Fifteen 7-month-old male senescence-accelerated miceresistant prone strain/1(SAMR1) were used as the control group. Each grouphas been treated with the corresponding method such as LW(in the LW group),HUP(in the HUP group) and physiological saline(in the model group and thecontrol group) for thirty days. After a month, we observed the abilityof learning and memory of all the mice by the test of Morris water mazeand got the data in the Place Navigation Training and the Spatial ProbeTest. After finishing 5 days'Morris water maze test, we killed all themice, collected their blood by excising the eyeballs and separated cortexand the hippocampus from the brain tissue. The blood was centrifuged andthe serum was pipetted into other EP tubes. All these samples were frozenfor use. Enzyme-linked immunoabsorption assay(ELISA) was performed toassay the expression of IL-2,IL-6 in all the hippocampus samples; Theprotein level of the hippocampus samples was determined in a 96 well plate by a micro-method. The data were analyzed statistically by SPSS11.0.Results1 The Morris water maze test includes two parts: Place Navigation Trainingand the Spatial Probe Test.1.1 Place Navigation Training(1) Trend of the five-day changes: As time went on, the escape latencieswere shorter gradually. And the later four days of the escape latency weresignificantly shorter than that of the first day (P＜0.01). That indicatedthat the learning and memory ability of mices were improved through arepeated way. Trend of the changes in speed became stable on the forthand the fifth day. Trend of the changes in distance and primary angelshowed that the distance and primary angel became shorter and smaller astime went on, which perhaps connect with improvement of mices'learningand memory ability.(2) Comparisons between the seven groups. Compare with control group, theescape latency and swimming distance of model group were longersignificantly (P＜0.01). Compare with LW group,Sijunzi group and Guipigroup, the escape latency of model group were significantly longer(P＜0.01).1.2 Spatial Probe TestThe time of the seven groups in the fourth quadrant (the position ofthe platform)showed that no significant change observed among the groups.2 The results of Micro-method for protein measurement in the hippocampusshowed that the regression coefficient R was 0.998, which presents a goodconsistency among the points of the standard curve and accuracy in theresults.3 Expression assay of IL-2 and IL-6. Enzyme-linked immunoabsorptionassay(ELISA) was performed to detect the expression of IL-2 and IL-6. Theconcentration (pg/ml) of IL-2 in hippocampus samples was sorted as thefollowing: control group＞Guipi group＞Piracetam group＞Sijunzi group＞DSS group＞LW group＞model group. The records of model group weresignificantly lower than the control group and the records of Guipi groupwere significantly higher than the model group. The concentration (pg/ml) Sijunzi group＞Piracetam group＞LW group＞model group. The records of modelgroup were significantly lower than the control group and the records of Guipigroup were significantly higher than the model group.Conclusions1. The ability of learning and memory of 8 month-old SAMP8 was lower than SAMR1,so SAMP8 was successful AD model.2. The concentration of IL-2, IL-6 in SAMP8 samples were significantly lowerthan SAMR1, this maybe related with learning and memory disorders3. The results showed that LW group,Sijunzi group,Guipi group could improvethe learning and memory ability of SAMP8.4. In the Morris water maze test, there were no significant changes observedamong the four TCM therapeutic prescriptions groups. So we could not make surewhich one was better.5. The Guipi group could improve the learning and memory ability of SAMP8.one of the mechanism was likely to make the expression of IL-2, IL-6. Theconcentration of IL-2,IL-6 in the LW group,Sijunzi group, DSS group groupdid not significantly change.