Aim: To compare the anticholinesterase effects of huperzine A (Hup A), E2020, and tacrine in rats.
Methods: Spectrophotometry was used to determine AChE activity in brain and BuChE activity in serum.
Results: Following intragastric gavage, Hup A, E2020, and tacrine all produced dose-dependent inhibitions of brain AChE. Oral Hup A exhibited a higher inhibition than E2020 and tacrine. Tacrine was more effective in inhibiting serum BuChE correlated with severe peripheral adverse effects. The BuChE activity was less affected by Hup A and E2020. After a single oral dose of Hup A, a relatively steady state of AChE inhibition produced, which was longer than that after E2020 and tacrine. No change in the cholinesterase inhibition was seen for the 3 drugs following repeated i.g. medications.
Conclusion: Hup A i.g. exhibited a higher efficacy, a longer duration of action, and a more selective inhibition on AChE than E2020 and tacrine.