Effect of Nigella sativa and wheat germ oils on scopolamine-induced memory impairment in rats

Aim: To investigate the possible memory enhancing effects of Nigella sativa oil (NSO) and wheat germ oil (WGO) on scopolamine-induced amnesic rats. Methods: Male Wistar rats received either saline or scopolamine (16 mg/kg, i.p.). The other three groups were pretreated with NSO (1 ml/kg, p.o.), WGO (170 mg/kg, p.o.) or donepezil used as a reference drug (10 mg/kg, p.o.) for 14 days before scopolamine injection. Cognitive and biochemical measurements were then assessed. Principal results: NSO and WGO treated rats significantly reversed scopolamine-induced deficit of spatial and non-spatial working memory impairment in the T maze alternation task and object recognition test, respectively. Administration of NSO prior to scopolamine showed a significant decrease in malondialdehyde (MDA) and increase in Glutathione (GSH) brain contents to be similar to that observed in donepezil group. It did not alter cholinesterase activity and showed a significant decrease in brain tumor necrosis factor-alpha (TNF-α) content to be similar to donepezil-treated rats. Scopolamine-demented rats pretreated with WGO did not change MDA brain content significantly as compared to scopolamine and donepezil groups. WGO-treated rats showed a significant increase in GSH to a level similar to that observed in the donepezil group, it showed a significant decrease in cholinesterase activity as compared to scopolamine group and significantly elevated brain TNF-α content when compared to donepezil group. Conclusions: Memory enhancing effect of NSO in the present study might be due to its antioxidant and anti-inflammatory activities, while that of WGO might be via its antioxidant and anticholinesterase activities.