Antiamnesic Activity of Extracts and Fraction of Desmodium Gangeticum

Desmodium gangeticum D.C. (Salpani; family – Papilionaceae) has been traditionally used in the treatment of various ailments especially in dementia. Thus, it was planned to screen antiamnesic activity of D. gangeticum to validate its traditional claims. Properly identified powdered plant material was extracted successively using solvents in increasing order of polarity viz., n-hexane, chloroform, methanol and water. All the extracts were administered at the doses of 200 or 400 mg/kg, p.o. for six successive days to mice. The antiamnesic activity of crude extracts was evaluated against scopolamine (0.6 mg/kg, i.p.) induced amnesia using well established exteroceptive behavioural model, i.e., elevated plus maze (EPM). The efficacy of test drugs was statistically compared with the standard memory enhancing drug, piracetam (100 mg/kg, p.o.). A standardized procedure was adopted to prepare alkaloidal fraction from D. gangeticum roots, which was also evaluated for antiamnesic activity at the doses of 25 or 50 mg/kg, p.o. The chloroform extract and alkaloidal fraction of the plant significantly reversed the amnesia induced by the scopolamine at the dose of 400 and 50 mg/kg, respectively, with respect to control. The antiamnesic activity shown by the chloroform extract and alkaloidal fraction of the plant was statistically equivalent to the standard drug. It is concluded that alkaloids are responsible for antiamnesic activity of D. gangeticum roots.