The aim of this study was to evaluate the protective effects of dietary flavonoid quercetin against Alzheimer's disease (AD) and detect the explicit administration of quercetin in early-middle or middle-late stage of AD pathology could play the effect as well as its mechanism of action. In this study, APP/PS1 mice were used to investigate cognitive impairment and related pathologies. The results showed that quercetin enrich diet could play an ameliorated pathology development of AD in APP/PS1 mice. And then we next determined administration of quercetin in early-middle and middle-late stage of AD pathology, which exerted that only quercetin enrich diet during the early-middle stage of AD pathological development period ameliorates cognitive dysfunction and the protection effect was mainly related to increased Aβ clearance and reduced astrogliosis. These findings suggest a possible new protective role for dietary flavonoids on AD. This new role might expand the preventive and/or therapeutic use of AD in conditions.
Keywords: Quercetin; alzheimer’s disease; flavonoid.