Naringenin from <i>Citrus junos</i> Has an Inhibitory Effect on Acetylcholinesterase and a Mitigating Effect on Amnesia

This study was performed to identify safe and more effective acetylcholinesterase (AChE) inhibitors in the treatment of Alzheimer's disease. The total methanol extract of Citrus junos had a significant inhibitory effect on AChE in vitro. By sequential fractionation of C.junos, the active component was finally identified as naringenin. Naringenin inhibited AChE activity in a dose-dependent manner. In this study, we also evaluated the anti-amnesic activity of naringenin, a major flavanone constituent isolated from C. junos, in vivo using ICR mice with amnesia induced by scopolamine (1 mg/kg body weight). Naringenin, when administered to mice at 4.5 mg/kg body weight, significantly ameliorated scopolamine-induced amnesia as measured in both the passive avoidance and the Y-maze test. These results suggest that naringenin may be a useful chemopreventive agent against Alzheimer's disease.