Effect of Cinnamomum Zeylanicum Extract on Memory and Hippocampal Cell Density in Animal Model of Diabetes

Neuropathy is the most common abnormality in diabetes mellitus which characterized with cerebral damages especially in hippocampus. This study evaluates the effect of Cinnamomum Zeylanicum extract (CZE) on memory, hippocampal neuron damage and antioxidant enzymes levels in animal model of diabetes. 50 adult Sprague dawley rats were randomly divided into 5 groups: Control, STZ (Streptozotocin, 50 mg/kg; i.p.), and STZ + CZE100, STZ + CZE200 and STZ + CZE400 which were treated with CZE in 100, 200 and 400 mg/kg, respectively. CZE was administered in 14 days, orally. After evaluation of working and spatial memory, activity of catalase (CAT) and glutathione peroxidase (GPx) enzymes was assessed by ELISA. Then, histopathological assessment of hippocampus was done. Findings: In comparison with the controls, STZ group showed an increase in latency time and distance to the hidden platform in MWM, a decrease in alteration behaviors, cell density and activity of CAT and GPx enzymes in hippocampus (p˂0.05). In addition, treatment with CZE decreased latency time and distance in MWM and increased alteration behavior, hippocampal cell density and activity of antioxidant enzymes in comparison with the STZ group (p˂0.05). Diabetes with reduction of neuronal density and activity of antioxidant enzymes in the hippocampus causes deficits in spatial and working memory. However, Administration of CZE ameliorates these neuropathologic disorders.