Introdction: Impaired cognitive function and memory, a characteristic of Alzheimer's disease, can be caused by several reasons and there is no definite treatment for it yet.
Materials and methods: Hydroalcoholic (25, 50, 100, 200 mg/kg), methanolic (20, 40 mg/kg) and hexane (40, 60 mg/kg) extracts of brown algae sargassum angustifolium were administered 21 days before scopolamine injection (2mg/kg). Then animal memory were evaluated by three behavioral test; passive avoidance, object recognition and Morris Water Maze test.
Results: Scopolamine induced memory impairment and rivastigmine was able to significantly reverse its effect in all tests. Hydroalcoholic and methanolic extracts significantly reversed scopolamine-induced memory impairment in passive avoidance and enhanced Recognition Index in object recognition test. In morris water maze test probe trial and training session, on day 3 and 4, hydroalcoholic extract showed significant decrease in time spent in target quadrant and path length respectively. Also hydroalcoholic and methanolic extracts decreased escape latency time in training session on day 3 and 4, in comparison to scopolamine. Hexane extracts had no significant effect on scopolamine- induced cognitive impairment.
Conclusion: Results of this study showed that administration of hydroalcoholic and methanolic extract of sargassum angustifolium enhance scopolamine–induced memory impairment. Although hexane extract wasn’t effective.