Effect of echinacoside on monoamine neurotransmitters in hippocampus and cortex of rats with Alzheimer′s disease / 中国药理学通报

ABSTRACT

Aim To investigate the influence of echi-nacoside ( ECH ) on monoaminergic neurotransmitter extracellular of the hippocampus and cerebral cortex in rat model of Alzheimer′s disease ( AD) , and ultimately to provide a theoretical basis for ECH′s improving the ability of learning and memory. Methods 60 male SD rats were randomly divided into 6 groups with 10 rats in each group sham operation group, model, ECH groups of low, medium and high doses (10, 20, 40μg ·g-1 ·d-1 ) , and Hup A ( Huperzine A, 0. 02 μg· g-1·d-1) group. The AD rat model was established by abdominal cavity injection with D-galactose and uni-laterally injected with amyloid beta-protein fragment 25-35 ( Aβ25-35 ) into the right hippocampus. Morris wa-ter maze test was used to study the animals′ ability of spatial learning and memory. The synchronous dual-probe dual-channel brain microdialysis sampling tech-nology was applied to collect dialysates from different encephalic areas continuously, and combined with HPLC electrochemical detection were used to measure the extracellular levels of norepinephrine ( NE) , dopa-mine (DA), 5-serotonin (5-HT). Results 1. Com-pared with the sham operation group, the mean escape latency of the model group was significantly prolonged ( P<0. 05 ) , and the time that rats were in the plat-form quadrant was significantly shortened ( P<0. 05 );on the contrary, compared with the model group, the mean escape latency of ECH groups were significantly shortened ( P<0. 05 ) , and the time that rats were in the platform quadrant was significantly extended ( P<0. 05). 2. Compared with the sham operation group, the contents of NE,DA and 5-HT were significantly de-creased in the model group ( P <0. 05 ) . However, compared with the model group , ECH could improve the concentrations of NE, DA, 5-HT in the hippocam-pus and cerebral cortex, and these monoamine levels of the brain regions were restored to near control. Con-clusion ECH can effectively improve the ability of learning and memory of rats with AD, giving a rise to the monoamine neurotransmitter both in hippocampus and cortex, exerting a positive effect on treatment of cognitive dysfunction . The ECH low dose group is sig-nificantly lower than the ECH groups of medium and high doses and Hup A group in improving the ability of learning and memory.