Quercetin attenuates spontaneous behavior and spatial memory impairment in d-galactose–treated mice by increasing brain antioxidant capacity

Quercetin, one of the flavonoids in fruits and vegetables, has a powerful antioxidant activity both in vitro and in vivo. To evaluate the antiaging effects of quercetin on the mouse brain, we investigated whether long-term intake of quercetin could improve spontaneous behavior and spatial memory in a mouse aging model. d-Galactose, known to induce age-related biochemical changes of the rodent brain, was used to develop the mouse aging model. In the present study, mice were subcutaneously injected with d-galactose (50 mg/kg) for 8 weeks and were administered quercetin via gastric intubation simultaneously. Animal behavior was observed in the open field and Morris water maze task. The results showed that quercetin significantly prevented changes of spontaneous behavior and spatial memory of d-galactose–treated mice. The antiaging effect of quercetin was found to be related to its ability to inhibit biochemical changes in hippocampi and cortices of d-galactose–treated mice. Quercetin increased brain glutathione level, hydroxy radical scavenging ability, and Na+,K+-adenosine triphosphatase activity, but decreased brain nitric oxide synthase activity and mitochondrial malondialdehyde content in d-galactose–treated mice. In conclusion, quercetin attenuated d-galactose-induced behavioral impairments, suggesting a potential antiaging effect of quercetin.