Neuroprotective effect of sinapic acid in a mouse model of amyloid β1-42 protein-induced Alzheimer's disease

Sinapic acid (SA) is a phenylpropanoid compound with anti-inflammatory and neuroprotective activities. The neuroprotective effects of SA in a mouse model of amyloid beta (A beta)(1-42) protein-induced Alzheimer's disease (AD) were investigated. Mice received a bilateral injection of A beta(1-42) protein into the hippocampus to verify the efficacy of SA. Mice were treated with SA (10 mg/kg/day, p.o.) for 7 days beginning immediately after A beta(1-42) protein injection, and an acquisition trial of the passive avoidance task was conducted 1 h after the last administration of SA. Retention trial was conducted 24 h after the acquisition trial, and mice were sacrificed for immunohistochemistry immediately after the retention trial. SA rescued neuronal cell death in the hippocampal CA1 region and also attenuated the increase of iNOS expression, glial cell activations and nitrotyrosine expressions induced by A beta(1-42) protein. SA significantly attenuated memory impairment in the passive avoidance task. These results suggest that SA ameliorated A beta(1-42) protein-related pathology including neuronal cell death and cognitive dysfunction via its anti-oxidative and anti-inflammatory activities, and may be an efficacious treatment for AD. (C) 2012 Elsevier Inc. All rights reserved.