Improvement of Learning and Memory by Morin, A Flavonoid in Young and Aged Mice

Background and Objectives: Flavonoids have been reported to possess neuroprotective effects. The present study was designed to evaluate the effect of morin, a flavonoid, on learning and memory of Swiss albino young and aged male mice. Methodology: Morin (10, 20 and 40 mg kgG1, p.o.) and physostigmine salicylate (0.1 mg kgG1, i.p.) were administered for 15 successive days to separate groups of young and aged mice. Morris water maze was employed to study the effect of the drugs on the learning and memory of mice. In addition, brain acetylcholinesterase activity was estimated. To explore the possible mechanisms of action, effect of morin on scopolamine and sodium nitrite-induced amnesia in young mice were investigated. Results: Morin (10, 20 and 40 mg kgG1) and physostigmine per se significantly decreased escape latency during training and increased time spent in target quadrant during retrieval, indicating significant improvement in learning and memory of young and aged mice as compared to their respective controls. The drug treatments have no significant effect on locomotor activity of the mice. Memory-enhancing activity of morin (20 mg kgG1, p.o.) was comparable to physostigmine. Morin significantly reversed scopolamine and sodium nitriteinduced amnesia in young mice. Morin and physostigmine also significantly reduced brain acetylcholinesterase activity of young and aged mice as compared to their respective controls. Conclusion: Morin administered for 15 successive days showed significant improvement of learning and memory of young and aged mice probably by inhibiting brain acetylcholinesterase activity. In addition, memory improving effect of morin in young mice might also be through facilitation of anti-hypoxic pathway leading to augmentation of cholinergic system.