Cognitive decline and memory impairment induced by disruption of cholinergic neurons and oxidative brain damage are among the earliest pathological hallmark signatures of
Alzheimer's disease.
Scopolamine is a postsynaptic
muscarinic receptor blocker which causes impairment of
cholinergic transmission resulting in cognitive deficits. Herein we investigated the effect of
QTC-4-MeOBnE (1-(7-chloroquinolin-4-yl)-N-(4-methoxybenzyl)-5-methyl-1H-1,2,3-triazole-4-carboxamide) on memory impairments in mice chronically treated with
scopolamine and the molecular mechanisms involved. Administration of
scopolamine (1 mg/kg) for 15 days resulted in significant impairments in working and short-term memory in mice, as assessed by the novel object recognition and the Y-maze paradigms. However, both deficits were prevented if mice receiving the
scopolamine were also treated with
QTC-4-MeOBnE. This effect was associated with an increase in
antioxidant enzymes (
superoxide dismutase and
catalase), a reduction in lipid peroxidation, and an increase in Nrf2 expression. Moreover, brains from
QTC-4-MeOBnE treated mice had a significant decrease in
acetylcholinesterase activity and
glycogen synthase kinase-3β levels but an increase in
brain-derived neurotrophic factor and Bcl-2 expression levels. Taken together our findings demonstrate that the beneficial effect of
QTC-4-MeOBnE in a mouse model of
scopolamine-induced memory impairment is mediated via the involvement of different molecular pathways including oxidative stress, neuroplasticity, neuronal vulnerability, and apoptosis. Our study provides further evidence on the promising therapeutic potential of
QTC-4-MeOBnE as a multifactorial disease modifying
drug in AD and related dementing disorders.