Learning and Memory Effect of Syringic Acid on Amyloid-β-induced Neurotoxicity in ICR Mice

Abstract

To investigate the in vivo cognitive effects of syringic acid(SA), Y-maze and passiveavoidance tests were performed in amyloid-β(Aβ)-induced cytotoxicity. Learning and memoryimpairment by Aβ neurotoxicity was partially recovered in Institute of Cancer Research(ICR)mice orally administered SA(10mg/kg of body weight). The SA treated group showed aninhibitory effect on acetylcholinesterase(AChE) that was extracted from mice brain tissue after invivo tests. Aβ-induced oxidative stress was also examined by malondialdehyde(MDA) and2',7,-dichlorofluorescein diacetate(DCF-DA) assays, and lipid peroxidation of brain homogenatesand cellular oxidative stress were reduced by SA. In cell viability assays using3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide(MTT), lactate dehydrogenase(LDH)leakage, and caspase 3/7 activity, the SA treated group showed relatively effective protectionagainst Aβ-induced neurotoxicity compared to the others. Consequently, these results suggest thatSA in black soybean seed coat extract might improve cognitive function because of its neuronalcell protective effects against oxidative stress and the inhibitory effect of AChE as a cholinergicenzyme.