Neuroprotective Effect And Intestinal Flora Of APP/PS-1 Double Transgenic AD Mice Induced By Flavones From Vitis Vinifera L.

Objective: To study the effects of Flavones from Vitis vinifera L.(VTF)on neuroprotective influence and intestinal flora of APP/PS-1 transgenic mice model of Alzheimer disease.Method: 1)AD mice casually divide into model group,Donepezil group,VTF low-dose,medium-dose and high-dose groups,and select C57BL/6 mice as wild control group,with 15 mice in each group.Each group intragastric administration for8 weeks,Morris water maze testing should be employed to evaluate the spatial learning aptitude of mice after intragastric administration.2)Immunohistochemistry and Western Blot were used to observe the expression of APP and IBA1 protein in mouse brain tissue.Use ELISA to observe the contents of IL-1β,IL-6 and TNF-α in the brain of mice.3)HE staining was used to observe the colonic tissue morphology,use IHC and WB to observe the protein expression of Occludin,Claudin,Zo-1 and NLRP3.Fecal intestinal flora of mice was examined by high-throughput sequencing.Results: 1)The results of water maze experiment showed that the mean escape latency of VTF low-dose group was shortened(P<0.05).Movement distance,movement time and entry times of VTF in low and medium dose groups were significantly increased(P<0.01);2)Brain immunohistochemistry showed that VTF could reduce the positive expression levels of APP and IBA1 protein(P<0.01),and WB showed that VTF could lower the relative expression levels of APP and IBA1 protein(P<0.05).3)ELISA results: VTF groups could reduce IL-1β,IL-6,TNFα and other inflammatory factors in brain tissue(P<0.01);4)The results of intestinal tissue HE staining showed intestinal mucosal layer atrophy,crypt loss and villi breakage in the model group,while the above conditions were alleviated in the VTF intervention group.5)Immunohistochemical results showed that VTF could increase the positive expression of tight junction proteins such as Occludin,Claudin and Zo-1(P<0.01),and lessen the expression of inflammation-related proteins of NLRP3(P<0.01).WB showed that VTF intervention can up-regulate Occludin,Claudin,Zo-1and other proteins(P<0.05),and down-regulate NLRP3 protein(P<0.05).6)Intestinal flora test results showed that: After VTF high dose intervention,the relative abundance of Firmicutes in AD mice increased(P<0.05).Compared with the model group,the relative abundance of Lactobacillaceae in VTF high dose group and Muribaculaceae in VTF low dose group increased,and Donepezil,Muribaculaceae in VTF low dose group increased.The relative abundance of Erysipelotrichaceae and Ruminococcaceae increased in each VTF dose group.However,the relative abundance of Lachnospiraceae,Helicobacteraceae and Deferribacteraceae decreased in each VTF dose group.Conclusion: VTF can effectively protect the nerve damage of AD mice and improve the learning and memory ability of AD mice.VTF intervention can protect the intestinal barrier damage of AD mice,reduce intestinal inflammation,with that playing a neuroprotective role.