Effect Of Dipsacus Root Extract On Learning And Memory Ability In Rats With Vascular Dementia

[Objective]To investigate the effects of Dipsacus Root Extract on learning and memory ability of rats with vascular dementia.[Methods]1. Acute toxicity test:32 rats were randomly divided into two groups (control group, experimental group). They were fasted 16h before the experiment, and 4h after filling the stomach, intragastric administrating 3 times a day,4h each time, experimental group were given the maximum concentration of Dipsacus Root Extract (0.3g/ml) and another group were given an equal amount of distilled water, according to the maximum stomach capacity of the rat (4ml/100g).Rats were observed for sequent 7days after administrated for 1 day. including eating, breathing, body hair, nose and mouth secretions, body weight and general condition of two groups of rats.2. Learning and memory experiment:48 male SD rats were randomly divided into normal group, sham operation group, model group and Dipsacus Root Extract of high, medium and low dose group,8 rats in each group. VAD models were induced by Repeating clipping bilateral common carotid artery. The treatment group were given corresponding dose (0.25g/kg,0.5 g/kg, 1g/ kg) of Dipsacus Root Extract solution;Sham operation and model groups were given the equal volume of distilled water, once a day, lasting 21days of intragastric administrating. Doing navigation experiment and space exploration experiment by the Miorris water maze. Determination of SOD, MDA and GSH in serum by enzyme linked immunosorbent assay.[Results]1. Acute toxicity testAcute toxicity could not be measured. Given maximum tolerated dose, during 7d of observation, the rats showed no obvious abnormalities about movement, breathing, eating, drinking water, hair, oral and nasal secretions, and weight. The rats were in good condition, no abnormal state and death. After anatomy, there were no obvious changes in major organs. The maximum daily does of Dipsacus Root Extrac is 0.3g/ml x 40ml/kg x 3 times=36g /kg, which was 135 times than the maximum amount in adult (16g/60kg).2. The effect of Dipsacus Root Extract on learning and memory abilities in rats with VAD① General state:During the experiment, the general state of all the rats were good, there were no significant difference in growth among four groups.② Affect of Dipsacus Root Extract on the ability of spatial memory and space exploration:The first two days, There was not statistically significant in each group rats for seeking platform latency. From the third day, middle and high dose groups rats seeking platform latency time significantly shortened compared with the model group (P<0.05), and crossing platform times were increased significantly than those in the model group after the withdrawal of platform (P<0.05).③ The influence of SOD, MDA, GSH in serum:In Dipsacus Root Extract and high dose groups. The level of SOD, GSH increased, MDA activity decreased, and there was statistical significance compared with the model group (P< 0.05).[Conclusion]1.The maximum dosage of Dipsacus Root Extract is 36g/kg for rats, It is 135 times than the maximum amountof adult, no significant toxicity, indicating Dipsacus Root Extract’s drug toxicity is very low.2. Dipsacus Root Extract can improve the ability of learning and memory of rats with vascular dementia, probably because it improves the level of SOD and GSH in rat serum, reduce the content of MDA.