Role of simvastatin and insulin in memory protection in a rat model of diabetes mellitus and dementia.

Citation:
Fahim, V. F., W. Wadie, A. N. Shafik, and M. I. Attallah, "Role of simvastatin and insulin in memory protection in a rat model of diabetes mellitus and dementia.", Brain research bulletin, vol. 144, pp. 21-27, 2019.

Abstract:

OBJECTIVES: The memory protective role of simvastatin and/or insulin, in a rat model of diabetes mellitus (DM) and dementia was examined.

METHODS: DM was induced by an intraperitoneal injection of streptozotocin. Diabetic rats were divided into untreated; insulin treated; simvastatin treated with 10 and 20 mg/kg/day; and combined insulin plus simvastatin treatment in the previous doses. Treatment started after blood glucose elevation and persisted for 6 weeks. Morris water maze and Y maze tests were held to detect behavioral changes. Serum glucose, cholesterol and insulin levels, the hippocampi insulin, amyloid beta (Aß) 1-42 and oxidative stress markers were measured.

RESULTS: Insulin increased the time spent in the target quadrant in the Morris water maze test and the percentage of alternations in the Y maze test, despite the mild improvements in brain parameters demonstrated by amyloid beta 1-42, malondialdehyde and reduced glutathione levels; while simvastatin in both doses improved brain parameters with no positive impact on behavioral tests. Insulin combined with simvastatin 20 mg/kg/day was effective in enhancing the behavioral tests and the measured brain parameters.

CONCLUSIONS: Treatment with insulin and simvastatin could provide a promising memory protective effect in diabetics.