Ameliorating effects of ethyl acetate fraction from onion (Allium cepa L.) flesh and peel in mice following trimethyltin-induced learning and memory impairment

The anti-amnesic effects of onion (Allium cepa L.) flesh (OF)11OF: onion flesh. and peel (OP)22OP: onion peel. on trimethyltin (TMT)33TMT: trimethyltin.-induced learning and memory dysfunction were investigated to confirm learning and memory function. The inhibitory effect against cellular acetylcholinesterase (AChE)44AChE: acetylcholinesterase. showed that the EtOAc fraction of OP (EOP55EOP: EtOAc fraction of onion peel., IC50 value=37.11μg/mL) was higher than the EtOAc fraction of OF (EOF66EOF: EtOAc fraction of onion flesh., IC50 value=433.34μg/mL). The cognitive effects in ICR mice were also evaluated using Y-maze, passive avoidance, and Morris water maze tests. After the behavioral tests, AChE activity (control=100%, TMT=128%, EOF 20=108%, EOP 10=104%, and EOP 20=98%), superoxide dismutase (SOD)77SOD: superoxide dismutase. activity, oxidized glutathione (GSSG)88GSSG: oxidized glutathione./total glutathione (GSH)99GSH: glutathione. and malondialdehyde (MDA)1010MDA: malondialdehyde. production were examined. These results indicate that both EOF and EOP improved learning and memory function. The main compounds of the EOF and EOP were analyzed by Q-TOF UPLC/MS, and the results were as follows: The EOF (quercetin and quercetin-4′-glucoside) and the EOP (quercetin-4′-glucoside and isorhamnetin-4′-glucoside). Consequently, our results suggest that both EOF and EOP could be efficacious in improving cognitive function through AChE inhibition and antioxidant activity in mice brains.