HUPERZINE-A, A NOVEL PROMISING ACETYLCHOLINESTERASE INHIBITOR

THE effects of huperzine A on memory impairments induced by scopolamin e were evaluted using a radial maze task and inhibition of cholinester ase in vitro compared with the effects of E2020 and tacrine. Scopolami ne (0.2 mg kg(-1)) significantly impaired spatial memory in rats. Hupe rzine A (0.1-0.4 mg kg(-1), p.o.), E2020 (0.5-1.0 mg kg(-1), p.o.) and tacrine (1.0-2.0 mg kg(-1), p.o) could reverse these scopolamine-indu ced memory deficits. The ratios of huperzine A, E2020 and tacrine for butyrylcholinesterase:acetylcholinesterase determined by a colourimetr ic method were 884.57, 489.05, and 0.80, respectively. The results dem onstrated that huperzine A was the most selective acetylcholinterase i nhibitor, and improved the working memory deficit induced by scopolami ne significantly better than did E2020 or tacrine, suggesting it may b e a promising agent for clinical therapy of cognitive impairment in pa tients with Alzheimer's Disease.