Eugenol improves learning and memory impairment through olfactory pathway on vascular dementia rats

Objective To study the effect of eugenol on learning and memory impairment caused by vascular dementia(VD)through olfactory pathway.Methods Thirty-two adult male Sprague-Dawley rats were randomly divided into 4 groups.There were normal control group(8 rats),sham-operated group(8 rats),VD group(8 rats) and treatment group(8 rats).VD group submitted to the right carotid occlusion with the left arotid ligated a week later,treatment group were treated with eugenol(1%) 3 days after surgery,and sham-operated group rats received the same surgical procedures without carotid artery ligation.In normal control group,the rats were not treated.Before surgery and 60 days after surgery,the rats were submitted to behavioral testing for learning and memory in the Morris water maze.Results Before surgery,there were no significant differences in the learning and memory capability between each group(P0.05).Sixty days after surgery,by comparing sham-operated group and normal control group,VD group had significant differences in the latency and the times through platform(P0.05).Aslo there were significant differences between treatment group and VD group in the latency and the times through platform(P0.05).Conclusion Eugenol can improve learning and memory impariment of vascular dementia through olfactory pathway.