[Effect and mechanism of dingzhixiao wan on scopolamine-induced learning-memory impairment in mice]

To investigate the effect of Dingzhixiao Wan (DZXW), a classic traditional Chinese medicine formula consisting of Acorus tatarinowii, Polygala tenuifolia, Poria cocos and Panax ginseng in a proportion of 2: 2: 3: 3, on learning-memory impairment induced by scopolamine and its possible mechanisms.

The mice were randomly divided into six groups: the control group, the model group, the positive huperzine A (0.05 mg x kg(-1)) group, DZXW 700 mg x kg(-1), 350 mg x kg(-1) and 175 mg kg(-1) groups. DZXW extracts were orally administrated to the mice for 7 days. Scopolamine (1.5 mg x kg(-1), ip) was injected to establish the learning and memory impairment model in mice. Morris water maze (MWM) test was used to assess the learning and memory ability of each group. After the test, the activities of glutamic acid (Glu), gamma-amino-butyric acid (GABA), serotonin (5-HT), dopamine (DA), acetylcholine (Ach) and acetyl cholinesterase (AchE) in brain tissue were measured.

The praxiology test showed that DZXW significantly decreased the average latency of model mice in the place navigation test, and enhanced the frequency for passing through the platform in the spatial probe test, the percentage between target quadrant swimming distance and time. Moreover, DZXW could significantly increase the contents of Glu and 5-HT, DA and Ach, while reducing the levels of GABA and AchE in mice brain.

DZXW could significantly ameliorate the scopolamine-induced learning-memory impairment in mice and improve their learning-memory capacity, which may be related to its effect on adjusting Glu/GABA system and increasing Ach and monoamine neurotransmitter contents in mice brain.