Effects of synthetic (-)-huperzine A on cholinesterase activities and mouse water maze performance.

AIM: To compare the effects of synthetic and natural (-)-huperzine A (Hup A) on cholinesterase and mouse water maze performance. METHODS: Spectrophotometry was used to determine cholinesterase activity. Mouse water maze was used to evaluate nootropic effect. RESULTS: The IC50 of synthetic Hup A for acetylcholinesterase (AChE) of rat cortex and rat erythrocyte membrane determined in vitro were 64.7 (52.6-79.5) and 53.9 (43.6-66.6) nmol.L-1, respectively, and for butyrylcholinesterase of rat serum was 53.6 (44.9-63.8) mumol.L-1. Synthetic Hup A 0.12-0.48 mg.kg-1 ig produced a dose-dependent inhibition of brain AChE in mice. Synthetic Hup A 0.05 mg.kg-1 ig attenuated scopolamine-induced impairment of spatial memory. The efficacy of synthetic Hup A was the same as natural Hup A. CONCLUSION: Synthetic Hup A yielded an in vitro and in vivo pharmacological profile of activities similar to that of natural Hup A.