Evaluation of Neuropharmacological Activity of Dioscorea bulbifera Using Various Experimental Models

Dioscorea bulbifera commonly known as Varahikanda, is widely distributed throughout the India, and it has been traditionally used for the treatment of nervous excitability, senility and hysteria. Based on this, neuropharmacological activity of tubers of D. bulbifera was evaluated using various experimental models. Effects of hydroalcoholic extract of Dioscorea bulbifera tubers (DBE) (10,30,100,300, and 1000 mg/kg, p.o.) was tested on behavioral profile of mice. Acute treatment of DBE (100 and 300 mg/kg, p.o.) was evaluated for spontaneous motor activity, motor coordination, pentobarbitone induced hypnosis, anxiolytic activity, exploratory activity and body temperature of mice. Phytochemical analysis of DBE indicates presence of terpenoids, saponins, glycosides, flavanoids, alkaloids, carbohydrates and proteins. DBE showed central nervous depressant action in general behavioral tests. The DBE showed significant (p<0.05) reduction of spontaneous motor activity and prolonged the pentobarbitone induced hypnosis in mice. Anxiolytic potential of DBE was observed by the results of elevated plus maze test in which DBE significantly increased number of entries and time spent in the open arms. Further, anxiolytic activity of DBE was confirmed by head-dip test in which exploratory activity of mice was increased significantly. However, DBE had no effect on motor co-ordination as determined by the rota rod test which confirmed central action rather than peripheral action of DBE. Moreover, CNS depressant action of DBE indicated by significant reduction of rectal temperature of mice. The findings of the present investigation indicate that the hydroalcoholic extract of D. bulbifera has central nervous depressant/sedative and anxiolytic potential which may be due combined effects of psychoactive principles.