The effect of chronic oral administration of loganin on spatial memory in diabetic male rats

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia and insufficiency of secretion or action of endogenous insulin. Hyperglycemia was associated with adverse effects on the brain activity and neuronal structural changes and impaired long-term spatial memory. Some studies have suggested that loganin as a plant-based drug has a plasma glucose-lowering action in normal rats. In this study the effect of chronic orally administration of loganin on spatial memory of diabetic male rats was evaluated. 21 male rats (250 - 300 g) were divided into 3 groups (control, diabetic and loganin- treated diabetic) groups. Diabetes was induced by single injection of streptozotocin in male rats (60mg/Kg, i.p). Loganin was administrated orally (40 mg/kg) and daily for 6 weeks. All groups were trained in Morris water maze for two consecutive days. Then learning parameters were compared between experimental groups. Our results showed that oral administration of loganin significantly(p<0.05) improved spatial learning and memory in diabetic rats. Loganin exhibits protective effect on spatial learning and memory in diabetic rats.