Comparative Study of the Effects of Metformin and Garlic Extract on Hippocampal Na⁺/K⁺ATPase, Ca²⁺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.

<i>Datura metel</i>Administration Distorts Medial Prefrontal Cortex Histology of Wistar Rats

Datura metel is one of psychoactive substances of great ethno-pharmacological significance often abused because of its unrestricted availability, yet, little is known about its mechanisms of action. This work was therefore aimed at assessing the activity of ethanolic seed extract of D. metel on Nissl substances, astrocytes, axonal and neuronal integrity of the medial prefrontal cortex (mPFC) of Wistar rats. Eighteen Wistar rats averaging 175 g were used and randomly assigned to three groups: group A rats (n = 6) were administered extract of 100 mg/kg bw, group B rats (n = 6) received extract of 200 mg/kg bw, and group C-control (n = 6) took distilled water only for 14 days. The results revealed that D. metel is deleterious to the health of Wistar rats at a dose-dependent rate as observed in its actions on the medial prefrontal cortex at 100 mg/kg bw and 200 mg/kg bw. The histological study of the treated Wistar rats exhibited features of disoriented neuronal integrity such as, chromatolysis, reduced protein synthesis due to loss of Nissl substances and nuclei, neuronal loss as well as axonal injuries.

Garlic Extract (<i>Allium sativum</i>) Enhances Spatial Working Memory in Wistar Rats: Involvement of Hippocampal Na⁺/K⁺ATPase and Ca²⁺ATPase Activities

Hippocampus plays a central role in the acquisition and recall of both episodic and spatial memory. Studies have shown that garlic has neuroprotective effects in various capacities and enhancement of different forms of memory. However, the effect of garlic spatial memory and direct effect of garlic extract on the activities of membrane bound enzymes Na+/K+ ATPase and Ca2+ ATPase in the hippocampus of rat still remain elusive. Therefore, we studied the effect of ethanolic extract of garlic on spatial working memory using object location memory OLM test and the hippocampal Na+/K+ ATPase and Ca2+ ATPase activities. Sixteen male wistar rats weighted 120 - 150 g were used and divided into two groups of eight rats each. The control and experimental groups were treated 1ml of normal saline and 500 mg/kg body weight of ethanolic extract of garlic respectively orally for three weeks. OLM test was carried out on the two groups. Animals were sacrificed and the brains were removed, and hippocampi were carefully excised and homogenate was obtained. Homogenate was analyzed for Na+/K+ ATPase and Ca2+ ATPase activities. There was significant increase in the exploration time in experimental group when compared with control group (p +/K+ ATPase and Ca2+ ATPase activities in experimental group when compared with control group (p +/K+ ATPase and Ca2+ ATPase. Our findings provide potential mechanism and therapeutic target for memory deficit neurological disorders.