Hypno-Sedative Activity of Gymnema sylvestre Extract in Sodium Barbiturate - Induced Hypnosis in Rattus novergicus

Abstract

Gymnema sylvestre is a rare herb with significant medical attributes and ethno-botanical uses. Insomnia is one of the most common sleep disorders around the world. In this study, the effect of the aqueous extracts of this plant was investigated for its hypno-sedative effect in rats as well as acute toxicity. Leaf, stem and flowers of G.sylvestre have several therapeutic applications in folk medicine in curing or managing of a wide range of diseases including insomnia. Sleep was induced using sodium barbiturate in albino rats. Rats of either sex weighing between 100-115g were grouped into five groups A,B,C,D and E of four animals each. Group A was the negative control and received only water, groups B the positive control received 10mg/kg b.w of diazepam .Groups C,D and E were administered 150,700 and 1500mg/kg b.w of extracts respectively, each of the rat was placed in individual cage and observed over a period of 24 hours at 6 hours interval .The aqueous extracts produced significant sedative effect at the dose of 150mg/kg b.w and was more effective than diazepam. The extracts at the doses of 150 and 700mg/kg b.w exhibited hypno-sedative activity comparable to the reference drug. The stem extract at 1500mg/kg produced no sedative effect. No toxicity signs were observed following acute toxicity evaluation. The extracts showed hypno-sedative activity at lower doses of 150mg/kg b.w in this increasing order, stem→leaf →flower. In conclusion, these results suggest that the aqueous extract of G. sylvestre is relatively non-toxic and possess potent sedative and hypnotic effects which could support its therapeutic use for insomnia in folk medicine.