Anticonvulsant and sedative activity of Tagara (Nymphoides macrospermum)

Abstract

Tagara (Valeriana jatamansi Jones) (Valerianaceae) is an important ayurvedic drug employed in several preparations used in the treatment of various diseases. In South India, a drug under the name Granthika tagara (Kannada), botanically identified as Nymphoides macrospermum Vasudevan (NM) (Menyanthaceae), is used in place of Tagara for the same ayurvedic preparations under the same formulations. The alcohol extract of N. macrospermum was tested for its anticonvulsant and sedative activities. Alcohol extract of NM at doses of 500 and 750 mg/kg body weight, significantly reduced the severity and increased the latency of convulsions induced by pentylenetetrazole (PTZ) and also reduced the time taken for recovery. However, NM up to a dose of 750 mg/kg body weight did not exhibit any significant effect on pentobarbitone-induced hypnosis. The sedative effect of the plant extract was confirmed by a significant reduction in locomotor activity, when tested using an actophotometer. The results indicate that the plant extract exhibits anticonvulsant and sedative activities justifying its use as a substitute for V. jatamansi in ayurvedic formulations. © 2007 Informa Healthcare.