Abstract: AIM: To explore the effects of Compound Yi-Zhi (YZC) on learning and memory capacity and free radical metabolism in D-galactose induced mice dementia model.METHODS: The mice dementia model was induced by a daily D-galactose 0.15 g·kg ^-1 sc for 45 d and after 5 d D-galactose injection, the mice were treated with three doses of YZC once a day for 40 d.In order to find out the influence of YZC on the models learning and memory capability and free radical metabolism system, Ymaze test was introduced for the former and superoxide dismutase (SOD) and malondialdehyde (MDA) tests for the latter.RESULTS: Compared with the D-galactose model group, three doses of YZC administration (0.108, 0.217, 0.433 g·kg ^-1) were all shown to significantly reduced the times of learning/memory in Y-maze test from 31.35 ±8.97/17.12 ±5.57 to 19.67 ±8.07/11.27 ± 6.65, to 14.00 ±6.84/8.29 ±5.95, and to 11.41 ± 5.99 6.24 ±4.97, respectively.For SOD, the administrations of 0.108 and 0.433 g·kg ^-1 YZC could increase the activity of SOD from 17.69 ±3.14 to 26.94 ±4.46, and to 21.33 ±3.63 nU·mg ^-1 pro.While for MDA, all the three doses of YZC could decrease the level of MDA from 4.08 ±0.88 to 2.82 ±0.75, to 2.10 ±0.42, and to 2.35 ±0.39 nmol·mg ^-1 pro in the mice brain tissue, respectively.CONCLUSION: YZC can improve the Dgalactose induced learning and memory dysfunction, and the action may be related to the improvement of antioxidase activity in the model mice brains.

Key words: pharmacology, compound Yi-Zhi, learning, memory, free radical, D-galactose