The Effect of Butter Oil on Avoidance Memory in Normal and Diabetic Rats

OBJECTIVE(S): Since diabetes mellitus is accompanied by cognitive impairment in diabetic patient and animal models and since lipids play important roles in neuronal membrane composition, structure and function; we intended to evaluate the effect of dietary butter oil on passive avoidance memory of streptoztosin (STZ)-induced diabetic rats in this study. MATERIALS AND METHODS: Thirty six adult male rats were randomly allocated to four equal groups: normal (N) and diabetic control (D) groups with free access to regular rat diet; but the diet of normal butter oil (NB) and diabetic butter oil (DB) groups was supplemented with 10% butter oil. Diabetes in D and DB groups was induced by intravenous (i.v.) injection of 50 mg/kg.bw of STZ. Passive avoidance memory and cholesterol of brain and hippocampal tissues has been measured six weeks after diabetes confirmation. RESULTS: Diabetes, especially in diabetic butter oil group decreased the abilities of learning and memory. The level of cholesterol in hippocampus was higher in NB (P< 0.05) and DB (P< 0.01) groups. CONCLUSION: We suggest consumption of butter oil may worsen cognitive impairment of diabetic animal. This may be related to the higher elevation of cholesterol in the hippocampus of diabetic animals.