Enduring amnesia induced by ICV scopolamine is reversed by sesame oil in male rats

Abstract

PURPOSE: To evaluated the long-term effect of scopolamine and sesame oil on spatial memory. METHODS: Memory impairment induced by Intracerebroventricular (ICV) injection of scopolamine hydrochloride (10 mu g/ rat). Animals were gavaged for 4 weeks with saline, sesame oil (0.5, 1, or 2 mL/kg/day), or 3 weeks with memantine (30 mg/kg/day) in advance to induction of amnesia. Morris water maze (MWM) test was conducted 6 days after microinjection of scopolamine. Then, blood and brain samples were collected and evaluated for the malondialdehyde (MDA) levels, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities, and total antioxidant status (TAS) and ferric reducing ability of plasma (FRAP). RESULTS: Scopolamine significantly decreased traveled distance and time spent in target quadrant in probe test. Pretreatment of rats with sesame oil (0.5 mg/kg) mitigated scopolamine-induced behavioral alterations. Measurement of MDA, SOD, and GPX in brain tissue, and FRAP and TAS in blood showed little changes in animals which had received scopolamine or sesame oil. CONCLUSIONS: Intracerebroventricular injection of scopolamine has a residual effect on memory after six days. Sesame oil has an improving effect on spatial memory; however this effect is possibly mediated by mechanisms other than antioxidant effect of sesame oil.