Eucommia ulmoides Oliv. Bark (EUE) is commonly used for the treatment of
hypertension,
rheumatoid arthritis,
lumbago, and ischialgia as well as to promote longevity. In this study, we tested the effects of EUE aqueous extract in graded doses to protect and enhance cognition in
scopolamine-induced learning and memory impairments in mice. EUE significantly improved the impairment of short-term or working memory induced by
scopolamine in the Y-maze and significantly reversed learning and
memory deficits in mice as measured by the passive avoidance and Morris water maze tests. One day after the last trial session of the Morris water maze test (probe trial session), EUE dramatically increased the latency time in the target quadrant in a dose-dependent manner. Furthermore, EUE significantly inhibited
acetylcholinesterase (AChE) and
thiobarbituric acid reactive substance (
TBARS) activities in the hippocampus and frontal cortex in a dose-dependent manner. EUE also markedly increased
brain-derived neurotrophic factor (
BDNF) and phosphorylation of cAMP
element binding protein (CREB) in the hippocampus of
scopolamine-induced mice. Based on these findings, we suggest that EUE may be useful for the treatment of cognitive deficits, and that the beneficial effects of EUE are mediated, in part, by
cholinergic signaling enhancement and/or protection.