REVERSAL OF SCOPOLAMINE-INDUCED DEFICITS IN NAVIGATIONAL MEMORY PERFORMANCE BY THE SEED OIL OF CELASTRUS-PANICULATUS

Celastrus paniculatus (CP), a medicinal plant from India has been repu ted to be useful as a pharmaceutical aid for learning and memory. We i nvestigated the effects of the seed oil of CP on the 6 day performance of young adult rats in a navigational memory task-the Morris water ma ze. Chronic oral (gavage) daily treatment with CP, (50, 200, or 400 mg /kg) for 14 days completely reversed the scopolamine (0.5 mg/kg)-induc ed task performance deficit. On the other hand, acute treatment (singl e injection prior to scopolamine treatment) with CP (200 mg/kg) did no t significantly reverse the scopolamine-induced impairment in maze per formance. Alone, CP produced a slight, but significant improvement in maze performance on the first day of testing. Acute treatment or chron ic 14 day treatment with CP resulted in no significant alteration in n ormal locomotor activity in an open field. Moreover, CP did not alter the scopolamine-induced increases in locomotor activity. Chronic treat ment with CP did not alter brain acetylcholinesterase levels and no si gns of cholinergic overstimulation were ever noted during or after tre atment. Thus, the seed oil of CP, when administered chronically, selec tively reversed the impair ment in spatial memory produced by acute ce ntral muscarinic receptor blockade, supporting the possibility that on e or more constituents of the oil may offer cognitive enhancing proper ties. The neural mechanism underlying the reversal of scopolamine's mn emonic effects by CP is not yet known, but it is not related to an ant icholinesterase-like action. (C) 1997 Elsevier Science Inc.