EFFECT OF HACHIMIJIOGAN, AN ORIENTAL HERBAL MEDICINAL MIXTURE, ON EXPERIMENTAL AMNESIA IN MICE

The effect of Hachimijiogan on cognitive disturbance was investigated using step-through passive avoidance failure techniques: scopolamine-, cycloheximide- and cerebral ischemia-induced amnesia. Pre-acquisition trial administration of Hachimijiogan (0.5 g/kg, p,o.) prolonged the step-through latency reduced by scopolamine and cyclohexidime. Hachimi jiogan (0.5 and 1.0 g/kg, p.o.) also ameliorated the cerebral ischemia -induced amnesia. Physostigmine (0.1 mg/kg, i.p.) ameliorated all thre e amnesia models. The ameliorating effects of Hachimijiogan and physos tigmine on cycloheximide-induced amnesia were diminished by the combin ation with scopolamine. These results suggest that Hachimijiogan posse sses a wide-ranging pharmacological profile in anti-amnesic actions an d that its anti-amnesic activities may be refitted to the cholinergic neuronal system.