The Effects Of Dl-3-n-butylphthalide On Learning And Memory Ability And Key Molecules Of RhoA/ROCK2 Signaling Pathway In Aging Rats

Objective:By observing the effects of Dl-3-n-butylphthalide（Dl-NBP）on Rho A/ROCK2 signaling pathway in aging rats and cells,to explore the mechanism of Dl-NBP in aging-related cognitive dysfunction.Methods:1.N2a（Neuro-2a,N2a）cells were treated with hydrogen peroxide solution（H₂O₂）in vitro to establish cellular senescence models,which were divided into control group（Con）and Dl-NBP group.The Con group did not receive any intervention.Dl-NBP group was treated with Dl-NBP 10μmol/L for 24 h on the basis of the Con group,and the samples were collected for examination.2.In vivo experiment,thirty 18-month-old male Sprague-Dawley（SD）rats were randomly divided into two groups.Rats in Dl-NBP group received Dl-NBP by oral gavage once daily for 2 months at a dose of 40mg/kg body weight and the Con groups were given the same amount of vegetable oil alone.Samples were collected for examination after behavioral testing of animals using the Morris water maze.3.Immunohistochemical（IHC）technique was used to detect the expression sites of Syn,PSD95 and p-CREB-1（133）in the samples.4.Western blot was used to detect the expression levels of Rho A,ROCK2,Syn,PSD95,and p-CREB-1（133）in the samples.Results:1.In vitro experiments:WB results showed that compared with the Con group,the expressions of Rho A and ROCK2 in Dl-NBP were decreased,and the differences were statistically significant（P<0.05）;the expressions of Syn,PSD95,and p-CREB-1（133）were increased,and the differences were statistically significant（P<0.05）.2.Morris water maze results:Compared with the Con group,rats in the Dl-NBP group had shorter time to explore the platform and increased the number of times they crossed the target quadrant,and the differences were statistically significant（P<0.05）.3.Immunohistochemical results showed that synapse-related proteins Syn,PSD95 and p-CREB-1（133）were widely expressed in rat hippocampus,PSD95 and p-CREB-1（133）were mainly expressed in neural cell membranes,and Syn was mainly expressed in the cytoplasm of neurons.4.In vivo experiments showed that the expression of Rho A and ROCK2 total protein was decreased in the Dl-NBP group compared with the Con group,and the differences were statistically significant（P<0.05）;the expressions of Syn,PSD95,and p-CREB-1（133）were increased,and the differences were statistically significant（P<0.05）.Conclusion:Dl-NBP can improve the learning and memory ability of aged rats,and its mechanism may be related to the promotion of the expression of synapse-related proteins and the inhibition of Rho A and ROCK2 expression.