Evaluation of Nootropic activity of Ethanolic and Aqueous Root Extracts of Adhatoda vasica nees in Rodents

Objectives: The Present study was planned to evaluate the nootropic activ- ity of ehanolic extract of Adhatoda vasica nees (EERAV) and aqueous ex- tract of A. vasica (AQERAV) in experimentally induced amnesic models in mice and rats. Methods: AERAV and AQERAV were prepared successively with roots of A. vasica using soxhlet apparatus. LD50 studies for these two extracts were carried out in albino mice up to the dose level of 2000 mg/kg as per guidelines No. 425 of CPCSEA. EERAV and AQERAV were studied for their nootropic effect evaluated in five different experimental models like Active (Rats) and Passive avoidance, Diazepam, Scopolamine, Sodium nitrite induced amnesia and Sodium nitrite induced hypoxia models all in mice. The parameters studied in nootropic activity are Step Down Latency (SDL), Step Down Error (SDE), Time spent in Shock Zone (TSZ), Number of shocks, Transfer Latency (TL) and Time for cessation of respiration. Results: No mortality observed even at the highest dose tested (2000 mg/ kg) and did not produce any significant effect on locomotor activity in mice. Experimental studies have shown that EERAV and AQERAV have exhibited a dose dependent nootropic activity. A Significant nootropic activity was recorded with both the extracts in Active and Passive avoidance, Scopol- amine, Diazepam and Sodium nitrite induced amnesia models. AQERAV exhibited a significant nootropic effect with medium and high doses only in Active and Passive avoidance models, scopolamine and Diazepam induced amnesia models. Conclusion: The present study suggests that both ex- tracts possessed a significant nootropic activity in mice and rats.