The Improving Effect And Mechanism Of Dingzhixiaowan On The Memory Dysfunction In Animals

Objective: To testify the preventive and curative effect of Dingzhixiaowan (DZXW) on the memory dysfunction in animals and to probe into its mechanism.Methods: (1) The rat model of retrograde spatial memory dysfunction was induced by maximal electro-convulsive shock (MECS) and the mouse model of memory impairments of acquisition, retention and retrieval was induced by scopolamine, sodium nitrite and ethanol. We compared the learning and memory ability of DZXW group with that of Zhengzhongjiannaoye (ZZJNY) group through Morris water maze experiment and step-down test. After DZXW ig, the preventive and curative effect on memory dysfunction, the numbers of spontaneous motor activity and the mouse's common behavior were observed. (2) The content of superoxide dismutase (SOD), Malon-di-alldehyde (MDA) in mice's brain was tested with chromatometry; and the content of the acetylcholinesterase (AchE) in mice's brain tissue after ig was tested with chromatometry and the content of norepinephrine (NE), dopamine (DA) and 5-hydroxytryptamine (5-HT) in rats' was tested with fluorospectrophotometry. The breathing time of mice after decapitation was also determined. The effect of DZXW on mice's cerebral ischemia and hypoxia was observed by the measurement of the decapitation-induced gasping duration. Thus, its mechanism was concluded.Results: (1) Both high dose and low dose groups of DZXW could shorten the searching platform time 30 min after MECS (p<0.01) andincrease the numbers of crossing platform 30 min and 24 hours after MECS. At the same time, DZXW could prolong the latency of mice's memory acquisition, retention and retrieval, reduce the errors (P<0.01, or P<0.05; except the that of low dose group of DZXW induced by scopolamine). But it didn't obviously affect mice's spontaneous motor activities significantly (P>0.05), which was the same with ZZJN group. (2) Both high dose and low dose groups of DZXW could significantly decrease the levels of MDA in the brain tissue of mice (p<0.01), but didn't influence the activity of SOD (p>0.05). DZXW groups could significantly increase the level of AchE in old mice's brain tissue (p<0.01), which was lower than that of normal young mice (p<0.01). The level of NE in old normal rats' cerebral tissue was significantly lower than that of young normal rats while levels of DA, 5-HT weren't. But both high and low dose groups of DZXW had no significant effect on the content of NE, DA and 5-HT in old rats' brain tissue. Moreover, both groups of DZXW could prolong the decapitation-induced gasping duration (P<0.01, or P<0.05) of the old normal mice that were obviously shorter than the young normal mice (p<0.01).Conclusions: DZXW could obviously prevent the retrograde amnesia of rats induced by MECS and alleviate the memory impairments of acquisition, retention and retrieval of mice without affecting the animals' general function. The mechanism might be related with DZXW which could reduce the level of MDA, increase the lowered the level of AchE in the old mouse's brain tissue and improve the anti-ischemia and antianoxic, but it was not related with SOD, NE, DA, 5-HT significantly.