Experimental Studies On Anti-Vascular Dementia Effects Of LST

Objective: The purpose of this paper was to study the anti-vascular dementia effects of LST and its mechanism. Methods: Using the methods of behavioral pharmacology including the one-trial step-down and the step-through passive advoidance test, Y-maze test and the water maze test to investigate the effects of LST against the vascular dementia induced by cerebral ischemia reperfusion in mice, middle cerebral artery occlusion(MCAO) model in rats and multi-infarct dementia (MID) model in rats. Furthermore, the antithrombtic effect of LST was also detected. Results: It reduced numbers of errors in step-down test, prolonged the latency of entry into dark room in step-through test, decreased the time of swimming from the original area to the goal area and increased the numbers of right reflects in water maze task in mice performed cerebral ischemia-reperfusion. In Morris water maze task LST shortened the latency of searching the hidden platform in directional swimming test and increased the time spent swimming in the target quadrant during 90s in probe test in rats performed MCAO and MID. Moreover, LST prolonged the latency of entry into dark room in step-through test and increased the percent alternation in Y maze task in these rats. Furthermore, a correlation between histological injury and behavioral deficits was shown pathologically. The increase of contents of malonic aldehyde (MDA) and the inhibition of superoxide dismutase (SOD)'s activity in the cerebrum in mice performed cerebral ischemia-reperfusion were significantly prevented by the administration of LST .Conclusion: Summarizing all the experimental results, LST showed the anti-vascular dementia effects. The mechanism maybe involve relieving the condition of cerebral ischemia, inhibiting the oxygen free radical reaction,elevating the activity of antioxidase in brain.