Effects Of LBP Treat AD Mice On Hippocampal Dentate Gyrus Neurogenesis And Microglia

Objective: The aim of this study was to investigate the effects of LBP treat AD mice on dentate neurogenesis,microglia and the ability of learning and memory, providing rationale for AD's prevention and cure.Methods: Adult healthy Kunming mice were randomly divided into 5 groups, the control group (CG), LBP high (HDG), middle (MDG), low (LDG) dosage groups and model of AD group (ADG), respectively. Except the control group, the other four groups injected with D-galactose and Sodium nitrite for 6 weeks, 120mg/(kg·d) and 80mg/(kg·d) respectively, ip. And at the same time, HDG, MDG and LDG lavaged with LBP, 2g/kg,1g/kg and 0.5g/kg respectively, ia. CG and ADG gave the same dose of Sodium Chloride. From the 7 week, we tested the spatial learning and memory ability of mice through the Morris Water Maze (WMM) training. We used the methods of immunohistochemistry to label the BrdU-positive cells with 5-bromo-2-deoxyuridine and the BSI-B4-positive cells with Bandeirae Simplicifolia Isolectin-B4. The number and disposition of BrdU-positive cells and BSI-B4-positive cells in subgranular zone of hippocampal dentate gyrus, were detected. To analyze the disparation of measurement data, we used the method of one-way ANOVA. Statistical correlation analysis was performed among the average frequence in MWM test, the dosage of LBP, the number of BrdU-positive cells, and the number of BSI-B4-positive cells. Results: 1, Successful model of AD mouse were built. Compared with CG, the mean latency of ADG was prolonged significantly from the third day (p<0.05). Till the fifth day, mice's learning ability of all groups of LBP was degraded greatly, but compared with ADG, the ability of that was improved. In probe trials, the mean frequences of CG was more than the others, compared with ADG, the mean frequences of HDG and MDG increased remarkably.2, Compared with CG, the number of BrdU-positive cells in SGZ of the other groups decreased notably, and all groups of LBP had more BrdU-positive cells than those of ADG.3, The difference of the BSI-B4-positive cells'number in SGZ between ADG and CG was statistically significant (p<0.01), and all groups of LBP had less BrdU-positive cells than those of ADG (p<0.05).4, The result of statistical correlation analysis indicated that, BrdU-positive cells have a positive correlation with frequences and the dosage of LBP (p<0.01), BSI-B4-positive cells have a negative correlation with those (p<0.01). Conclusion: LBP could promote neurogenesis and repress the activation of microglia, at the same time, LBP could degrade the impairment of learning and memory, that caused by AD, and have positive dose-dependence effect. The results suggested that LBP could improve the ability of learning and memory of AD, through promoting neurogenesis and repressing the activation of microglia.