Alzheimer's disease (AD) is one of the prevalent neurological disorders of the central nervous system
hallmarked by increased beta-amyloid (Aβ) deposition and ensuing learning and memory deficit. In the
present study, the beneficial effect of naringenin on improvement of learning and memory was evaluated
in an Alzheimer's disease rat model. The Aβ-injected rats showed a lower alternation score in Y-maze
task, impairment of retention and recall capability in passive avoidance test, and lower correct choices
and higher errors in radial arm maze (RAM) task as compared to sham group in addition to enhanced
oxidative stress and apoptosis. Naringenin, but not a combination of naringenin and fulvestrant (an
estrogenic receptor antagonist) significantly improved the performance of Aβ-injected rats in passive
avoidance and RAM tasks. Naringenin pretreatment of Aβ-injected rats also lowered hippocampal
malondialdehyde (MDA) with no significant effect on nitrite and superoxide dismutase (SOD) activity in
addition to lowering apoptosis. These results suggest naringenin pretreatment attenuates Aβ-induced
impairment of learning and memory through mitigation of lipid peroxidation and apoptosis and its
beneficial effect is somewhat mediated via estrogenic pathway.