Oxidative stress is a major factor implicated in the degeneration of
cholinergic neurons in Alzheimer’s Disease (AD). Several reports have indicated that antioxidant
intake is beneficial to delay or inhibit the progression of this disease. Presently, Acetylcholinesterase
(AChE) inhibitors are the mainstay of therapy for AD. Quercetin, one of the flavonoids in fruits and
vegetables, has a powerful antioxidant activity both in vitro and in vivo. However, the potential of
quercetin as Acetylcholinesterase (AChE) inhibitors, an important aspect for neuroprotection, has not
been properly investigated. Approach: This study was designed to evaluate the anti-cholinesterase
activity and improves cognitive function of quercetin liposomes via nasal administration in a rat
AF64A injection model of AD. Male Wistar rats were pretreated with quercetin liposomes, containing
0.5 mg of quercetin in 20 µL via intranasal route once daily continually for 3 weeks. Learning and
memory was evaluated using the Morris water maze test at 7 days after the lesioning and then the rats
were sacrificed for determining the contents of Acetylcholinesterase (AChE), the activities of
Superoxide Dismutase (SOD), Glutathione Peroxidase (GPx) and Malondialdehide (MDA), a lipid
peroxidation product in the hippocampus. Results: AF64A with nasal administration of free liposomes
showed the loss of cognitive performance in Morris water maze test, increase in the markers of
oxidative damage (MDA, SOD and GPX) and the AChE activity in the hippocampus. However,
AF64A with nasal administration of quercetin liposomes reversed all the parameters significantly.
Conclusion: Our studies demonstrated that quercetin liposomes via nasal administration may have a
therapeutic importance in the clinical management of Alzheimer’s disease