Comparative Study of the Effects of Metformin and Garlic Extract on Hippocampal Na + /K + ATPase, Ca 2+ ATPase and Glutamine Synthetase Activities in Type II Diabetic Wistar Rat

Diabetes mellitus has not ceased to be on rise in spite of the continuous research on its management. Brain dysfunction associated with Diabetes mellitus especially Type II has been the great concern. The aim of this study was to investigate the effect of insulin sensitizing drug metformin and ethanolic extract of garlic on membrane bound enzymes Na+/K+ ATPase, Ca2+ ATPase and glutamate-glutamine cycle enzyme, Glutamine Synthetase activities in the hippocampus of streptozotocin-Nicotinamide induced Type II Diabetic rats. Twenty four male wistar rats weighted 120 - 150 g were used and divided into four groups with six rats in each group. Group A was non-diabetic (Control) and Groups B, C and D were diabetic. Group B received no treatment (DNT) while Groups C and D were treated with 1000 mg/kg of ethanolic garlic extract (EGE) and 50 mg/kg of metformin (MET) respectively orally for three weeks. All the groups were fed on standard rat chow with water ad libitum. Blood glucose was monitored weekly. Animals were sacrificed and the brains were removed and hippocampi were carefully excised and homogenate were obtained. Homogenate was analyzed for Na+/K+ ATPase, Ca2+ ATPase and Glutamine Synthetase (GS) activities. MET and EGE significantly reduced the blood glucose levels. There was a significant increase in the activities of hippocampal Na+/K+ ATPase, Ca2+ ATPase and GS in MET and EGE when compared to DNT. The results suggest that both MET and EGE increase the activities of hippocampal Na+/K+ ATPase, Ca2+ ATPase and GS which were reduced by diabetes mellitus, thus garlic and metformin administration exhibiting neuroprotective effect during hippocampal-related disorders associated with diabetes mellitus.