Quercetin and quercetin-3-β-d-glucoside improve cognitive and memory function in Alzheimer’s disease mouse

We investigated the protective activities of quercetin (Q) and quercetin-3-β- d -glucoside (Q3G) under Aβ 25–35 -injected Alzheimer’s disease (AD) model mice. To induce an AD-like disease in an in vivo model, mice were injected with Aβ 25–35 via the intracerebroventricular route. Q and Q3G were administered orally for 14 days at 30 mg/kg/day. Learning and memory functions were evaluated using behavioral experiments that comprise tests like T-maze, Morris water maze, and novel object recognition. The administration of Q and Q3G improved memory and cognitive function, compared with Aβ 25–35 -injected control mice in the T-maze and object recognition test. Q and Q3G administration decreased time in order to get to the platform during the Morris water maze test. The group administered Q experienced higher protective effects from long-term spatial memory and learning ability impairments than the group administered Q3G. Furthermore, lipid peroxidation and NO formation in the brain were significantly elevated in Aβ 25–35 -injected control mice, and this was inhibited by Q and Q3G. These results demonstrated that Q and Q3G improved Aβ 25–35 -induced memory deficits and cognitive impairment and promoted protection in the brain against oxidative stress.