Antiamnesic effect of aqueous lyophilisate of Drymaria cordata on scopolamine-induced amnesia and oxidative stress in mice

Abstract

Background: Learning and memorization are the so-called higher functions of the brain whose alteration is at the origin of neurodegenerative diseases. Drymaria cordata (D. cordata) is a plant used in Cameroon to treat disorders such as convulsions and ulcers. The aim of this study was to evaluate the anti-amnestic effects of D. cordata on scopolamine-induced amnesia in mice and its potential antioxidant properties.

Methods: The Morris water maze was used to evaluate the spatial memory. Mice of both sexes were randomly divided in six and five groups and treated for 15 days with one of the following substances: distilled water, tacrine or D. cordata. The animals were simultaneously treated with scopolamine from day 12 to day 15 to induce amnesia. Assessment of D. cordata on memory was done by treating animals for 15 days without scopolamine. The Morris water Maze (MWM) and hippocampus acetylcholinesterase activity were used to assess memory integrity. Malondialdehyde and reduced glutathione levels were quantified in the hippocampus to assess antioxidant properties.

Results: D. cordata reversed scopolamine-induced amnesia in the Morris water maze as it spent more time in the target quadrant (p<0.01) and reduced acetylcholinesterase activity. D. cordata decreased malondialdehyde level, and increased glutathione level in the hippocampus of mice with amnesia (p<0.01) as compared to mice treated with distilled water. Mice treated only with D. cordata, spent more time in the target quadrant, decrease the acetylcholinesterase activity, reduced the MDA level although not significantly and significantly increased the glutathione level as compared to mice treated with distilled water(p<0.05).

Conclusion: These results suggest that D. cordata improves scopolamine-induced cognitive impairment through inhibition of oxidative stress and potentiation of cholinergic neurotransmission.