Abstract:

Objective  To observe the effect  Acanthopanax senticosus saponins (ASS) on experimental vascular dementia in rats induced by middle cerebral artery occlusion(MCAO) and provide basis for further development of ASS. Methods Wistar rats were randomly divided into sham group,model group and ASS (low dose，middle dose and high dose) groups. The experimental vascular dementia model induced by MCAO was set up in rats, 10 d later,they were treated by continuously intraperitoneal injection of 25,50 and 100 mg/kg^-1 ASS for 20 d. The abilities of learning and memory were evaluated by Morris water maze test. After detection the ethology,the brain tissues were collected to carry out pathological analysis by light microcope and homogenate to detect the activities of acetylcholine esterase (AchE)  and choline acetyl transferase(ChAT). Results In Morris water maze test,compared with model group,the escape latency and swimming distance were decreased in the 4th and 5th days (P<0.05 or P<0.01);and  the ratio of the swim time in the virgin platform quadrant (tP) and the total swim time (tT) and the ratio of the swim distance in the virgin platform quadrant (dP) and the total swim distance (dT) were increased significantly(P<0.05) in 50 and 100 mg/kg^-1 ASS groups. and the activity  of AchE was decreased significantly (P<0.05) in 50 and 100 mg/kg^-1ASS groups;the activity of ChAT in 100 mg/kg^-1 ASS group was increased significantly(P<0.05). The histopathological results indicated that there were marked focus of infarctionin the cerebr-blood-supply region by middle cerebral artery,the nerve cells of the  hippocampal CA1 fields of rats arrangeddisorderedly,the quantity of nerve cells was decreased markedly in  model group. 50 and 100 mg/kg^-1 ASS diminished the size of focus of infarction,protected the nerve cells of the hippocampal CA1 fields from disorder,maintained the quantity of nerve cells,andimproved the damage of brain. Conclusion ASS can improve the abilities  of learning and memory of vascular dementia rats and protect the brain tissue from pathological changes. Its mechanism may be related to increasing  the activity of ChAT, decreasing  the activity of AchE,and  promoting the synthesis of AchE.

Key words:  Acanthopanax senticosus saponins;vascular dementia;middle cerebral artery occlusion;rats,wistar