preparation and evaluation of chitosan coated nano-selenium loaded by donepezil on learning and memory impairment in rat

Aim and background: learning and memory disorders are one of the major problems in human societies. therefore, compounds that can enhance these two behavioral phenomena do a great service to many people with mental retardation and memory impairment. in recent years, much attention has been paid to nanoparticles as carriers for drug delivery. in the present study, a system of selenium nanoparticles loaded with donepezil was designed, which due to better drug delivery of donepezil to the brain, improves memory and learning disorders impaired by scopolamine, and this carrier system can be used for better drug delivery to the brain. methods: selenium nanoparticles were prepared by sedimentation method and loaded with donepezil and coated with chitosan. the study groups included the groups receiving normal saline, scopolamine, donepezil, uncoated nanoparticles containing donepezil, coated nanoparticles containing donepezil, uncoated nanoparticles and the group containing coated nanoparticles. the study of locomotor activity in the studied groups was performed by spatial memory test through morris water maze and passive avoidance test by shuttle box. the amount of malondialdehyde and antioxidant capacity in brain and serum tissues and the activity of acetylcholinesterase in brain tissue and red blood cells were measured.results and discussion: scopolamine administration significantly reduces memory and learning in the shuttle box and morris water maze tests; administration of donepezil can compensate for the destructive effects of scopolamine. chitosan-coated selenium nanoparticles loaded with donepezil significantly reduced brain tissue mda levels, increased brain antioxidant capacity, decreased brain tissue acetylcholinesterase activity, and thus compensated for the destructive effects of scopolamine (p <0.05).conclusion: the results of the present study showed that chitosan-coated and donepezil -loaded selenium nanoparticles improved the effect of brain acetylcholinesterase activity, lipid peroxidation and brain antioxidant levels on impaired memory and learning disorders in male rats and compensates for the observed effects of scopolamine