Gomisin A improves scopolamine-induced memory impairment in mice.

Gomisin A is a component of the fruits of Schizandra chinesis which are widely used as a tonic in traditional Chinese medicine. In the present study, we assessed the effect of gomisin A on the learning and memory impairments induced by scopolamine. The cognition-enhancing effect of gomisin A was investigated using a passive avoidance test, the Y-maze test, and the Morris water maze test in mice. Drug-induced amnesia was induced by treating animals with scopolamine (1 mg/kg, i.p.). Gomisin A (5 mg/kg, p.o.) administration significantly reversed scopolamine-induced cognitive impairments in mice by the passive avoidance test and the Y-maze test (P<0.05), and also improved escape latency in the Morris water maze test at 5 mg/kg (P<0.05). Moreover, in an in vitro study, gomisin A was found to inhibit acetylcholinesterase activity in a dose-dependent manner (IC50 value; 15.5 microM). These results suggest that gomisin A may be a useful cognitive impairment treatment, and its beneficial effects are mediated, in part, via enhancing the cholinergic nervous system.