To Study Banqiao Codonopisis Pilosula Improves Of Cognitive Dysfunction In AD Model Rats By PP2A Signaling Pathway

Objective: To investigate the protective effect of Banqiao Codonopsis pilosula(BCP)on cognitive function in rats with Alzheimer’s disease(AD)induced by Okadaic acid(OA)and its possible mechanism.Methods: The SD male rats were randomly divided into 10 groups: DMSO group,OA group,BCP lower-dose group,BCP medium-dose group,BCP high-dose group.And these groups ware divided into one week and two weeks.The DMSO and OA groups were treated with warm water.The OA group and BCP decoction group were intragastrically administered with low,medium and high doses of BCP decoction.In the one week group,the water maze training was started on the second day of the gavage.In the two week group,the water maze training was started on the 9th day of the gavage.The training time was 5 days,and the second day of training was completed.After 24 hours of modeling,the water maze was performed.The changes of spatial learning ability before and after modeling were observed.The levels of PME protein,PP2A-related protein,Tau phosphorylation and synaptic-related protein expression in hippocampus of each group were detected by immunoblotting.The number of nissl bodies in the hippocampus CA1 and CA3 areas and the changes in coloration were observe by nissl staining.Golgi staining was used to observe the changes in the morphology and quantity of dendritic spines in the hippocampus.Results: Morris water maze results showed that the spatial learning and memory ability of the AD rats in each group of BCP was significantly improved.Western blot analysis showed that BCP could increase the expression of PP2 A relate protein in hippocampus of AD rats by decreasing the expression of PME,and then down-regulate the phosphorylation of Tau protein,and also improve the synapse relate protein in hippocampus through high activity of PP2 A.Repair damaged neurons.The results of nissl staining indicated that the number of nissl bodies in the hippocampal CA1 and CA3 areas of the BCP group,especially in the two week group,increased significantly in a dose-dependent manner,indicating that BCP decoction can increase the nissl body.Protects neurons in AD model rats.The results of Golgi staining showed that BCP decoction could increase the number of dendritic spines in OA-induced AD model rats.Conclusion: Banqiao Codonopsis pilosula can improve the learning and memory ability of AD model rats induced by OA.The possible mechanism is that BCP can effectively increase the activity of PP2 A in hippocampus of AD rats by inhibiting the expression of PME,thereby inhibiting the hyperphosphorylation of Tau protein.At the same time,the expression of synaptic-related proteins and the number of dendritic spines were increased,and the damaged neurons were protected,which ultimately improved the cognitive dysfunction of AD model rats.