A Study On The Inhibiting Activity And Mechanism Of Artemether Against Aβ_25-35-induced Alzheimer’s Disease

Objectives:The present study aims to explore whether oral administration of artemether(ART)could attenuate the spatial learning and spatial memory deficits induced by Aβ25-35,and then to investigate the regulatory effects of ART on the expression level of BACE1,Aβ,mTOR and Tau proteins in N2a cells to explore the molecular mechanism of ART against AD.Taken together,the present study aims to lay the foundation for a safer,more effective and multitarget candidatate drug for AD treatment.Methods:SD rats(Sprague-Dawley rats)were used as the experimental animals and AD animal model was established through intracerebroventricular injection of Aβ25-35 solution.Behavioral test was performed through Morris water maze to investigate the injurious effects of intracerebroventricular injection of Aβ25-35 on SD rats’ spatial learning and spatial memory,and to evaluate the inhibiting activity of ART on the spatial learning and spatial memory deficits induced by Aβ25-35.N2a cells(Murine neuroblastoma cells)were treated with ART or rapamycin(RAPA)for 48h/72h respectively,and then the expression level of endogenous BACE1,Aβ,mTOR and Tau proteins in N2a cells was measured through Western blot to explore the molecular mechanism of ART against AD.Results:Place navigation showed that,compared with Aβ group,rats in both sham group and Aβ+ART group spent shorter escape latency(P<0.05)and there was no obvious difference in escape latency between Aβ+ART group and sham group,indicating that intracerebroventricular injection of Aβ25-35 impaired SD rats’ spatial learning,and artemether improved Aβ25-35-induced spatial learning deficits of SD rats.Spatial probe showed that,compared with Aβ group,rats in both Aβ+ART group and sham group presented more cross-platform time(P<0.05),indicating that intracerebroventricular injection of Aβ25-35 impaired SD rats’ spatial memory,and artemether improved Aβ25-35-induced spatial learning deficits of SD rats.In addition,in place navigation,rats in Aβ group showed obvious blindness to locate escape platform,whereas rats in Aβ+ART group and sham group showed specific purpose of locating escape platform.Moreover,in vitro experiment showed that ART/RAPA treatment downregulated the expression level of endogenous BACE1,Aβ,mTOR and Tau proteins in N2a cells(p<0.05).Conclusions:Oral administration of ART attenuated the spatial learning deficits and spatial memory deficits induced by intracerebroventricular injection of Aβ25-35,and ART treatment downregulated the endogenous expression level of BACE1,Aβ,mTOR and Tau proteins in N2a cells.Considering the role of BACE1,A β,mTOR and Tau proteins in AD pathology,the present study postulates herein that artemether may suppress Aβ-induced oxidative stress,neuroinflammation and nuerofibrillary tangles by directly or indirectly downregulating BACE1,Aβ,mTOR and Tau proteins.It’s noteworthy that RAPA treatment also downregulated the expression level of endogenous BACE1,Aβ,mTOR and Tau proteins in N2a cells,indicating that mTOR might be a key mediator of Aβ-induced neurotoxicities.Taken together,ART is prospective to be a safe,effective and multitarget anti-AD candidate drug.