Résumé
Aim of the study was to evaluate the anti-amnesic effects of Crataeva nurvala stem bark in scopolamine induced amnesia in rats. The standardized aqueous extract of Crataeva nurvala (AECN) was freshly dissolved in distilled water and administered orally to rats at the dose of 500 mg/kg for evaluation of its effects against scopolamine (3 mg/kg, i.p.) induced retrograde and anterograde amnesia. The effects of the extract on escape latency during the acquisition trial (Days 1-4) and the time spent in target quadrant (TSTQ) during the retrieval trial (Day 5) were determined using the Morris water maze test. In order to indicate the probable mechanism of C. nurvala, its effects on acetylcholinesterase (AchE) and TBARS levels in the brain were determined. In scopolamine induced retrograde amnesia treatment with AECN showed a significant (p<0.05) increase in TSTQ and reduction (p<0.001) in levels of both AchE and TBARS in brain. In the anterograde amnesia model AECN significantly (p<0.001) reduced the escape latency and increased (p<0.01) the TSTQ. The extract also lowered the levels of AchE (p<0.01) and TBARS (p<0.001) in the brain of scopolamine induced anterograde amnesic rats.The study proved that AECN possesses positive effects on memory and learning, which may be due to decrease in AchE levels and inhibition of lipid peroxidation in the brain.