Effects of andrographolide on cognitive function and hippocampal synaptic plasticity in the rats with vascular dementia

Objective To investigate effects of andrographolide( ANDRO) on the cognitive function and hippocampal synaptic plasticity in the rats with vascular dementia( VD). Methods From June to August in 2012,30 Sprague- Dawley( SD) rats were randomly assigned to treatment group( n = 10),model group( n = 10),and sham- operation group( n = 10). Middle cerebral artery occlusion was performed for 2 hours to establish rat models. ANDRO( 200mg / kg) was given to treatment group intragastrically,while saline( 2 ml) to both model group and sham group. The rats' cognitive ability was assessed by Morris' s water maze test. Western blot was used to detect synaptophysin expression in hippocampus. Measurement data were randomized into groups for analysis of variance. One- way analysis of variance was carried out on the data between groups,q- test was used for pairwise comparison among means,and the result of P 0. 05 was considered statistically significant. Results Morris' s water maze test revealed that for 4 consecutive days,the mean time of escape latency was in treatment group was shorter than that in model group,longer than that in sham- operation group( P 0. 05). The grey value ratio of synaptophysin in the hippocampus of the rats was( 0. 89 ± 0. 04) in sham- operation group,( 0. 83 ± 0. 02) in treatment group,and( 0. 79 ± 0. 01) in model group and with obvious differences among the groups( F = 123. 27,P 0. 05). Conclusions ANDRO can ameliorate the cognitive function of rats with VD,which may be involved in the protection of hippocampal synaptic plasticity.