Psychotropic activity of Argyreia speciosa roots in experimental animals

Argyreia speciosa (L.f.) Sweet (convolvulaceae) commonly known as Briddhadaraka is regarded as a "Rasayana" drug in the ayurvedic system of medicine to cure diseases of nervous system. In this study, hydroalcoholic root extract of A. speciosa was subjected to evaluate psychotropic effects in classical experimental models. Effect of the extract on spontaneous motor activity, pentobarbital-induced sleeping time, motor coordination, exploratory behavior, and apomorphine-induced stereotypy were investigated in mice. Effect of the extract on catalepsy and haloperidol-induced catalepsy were studied in rats. Preliminary phytochemical and acute toxicity screenings were also performed. The extract (100, 200, and 500 mg/kg, p.o.) significantly decreased spontaneous motor activity, exploratory behavior, and prolonged pentobarbital sleeping time in mice. The extract also remarkably attenuated the intensity of apomorphine-induced stereotypy but had no effect on motor coordination. The extract produced catalepsy and potentiated haloperidol-induced catalepsy in rats. These results provide evidence that the hydroalcoholic extract of A. speciosa roots may contain psychoactive substances that are sedative in nature with possible neuroleptic properties.