At present, the development of protective strategy against Alzheimer’s
Disease (AD) is increasing its importance due to the high prevalence of AD, a limitation of therapeutic
efficacy and its high impacts on economic and social aspects. The development of the preventive and
therapeutic strategy to protect against the path physiology induced by free radicals in AD from
antioxidant has gained very much concentration. Quercetin, one of the flavonoids in fruits and
vegetables, has a powerful antioxidant activity both in vitro and in vivo. However, poor absorption,
rapid metabolism and limited ability to cross the blood-brain-barrier are obstacles to its use for
treatment of AD. Liposome’s have been used as an effective delivery system to the brain. Advantages
associated with the nasal administration over oral route include higher bioavailability due to no first
pass hepatic metabolism and rapid absorption leading to shorter time to onset of effect. Based on all
these points, the possible effects of quercetin liposomes via nasal route on improving cognitive
behavior and neurodegeneration in animal model of Alzheimer’s disease were investigated.
Approach: Male Wistar rats were pretreated with quercetin liposome’s, containing 0.5 mg of
quercetin in 20 µL (dose = 20 µg), via intranasal route once daily continually for 2 weeks before and
1 week after AF64A administration. Learning and memory was evaluated using the Morris water maze
test at 7 days after the AF64A administration and then the rats were sacrificed for determining the
density of neurons and cholinergic neurons in hippocampus using histological and
immunohistochemical techniques. Results: Nasal administration of quercetin liposome’s significantly
prevented changes of spatial memory of AF64A treated rats. The cognitive enhancement of quercetin
liposome’s was found to be related to its ability to inhibit the degeneration of neurons and cholinergic
neurons in hippocampus. Conclusion: Nasal administration of quercetin liposome’s possessed
cognitive enhancer and neuroprotectant in animal model of AD, suggesting a potential novel
therapeutic strategy against AD of quercetin liposomes.