Evaluation of Sedative and Hypnotic Activity of Ethanolic Extract of Scoparia dulcis Linn.

Scoparia dulcis Linn. (SD) is a perennial herb that has been well studied for its antioxidant, anti-inflammatory, antidiabetic, and hepatoprotective effects. However, scientific information on SD regarding the neuropharmacological effect is limited. This study evaluated the sedative and hypnotic effect of the ethanolic extract of whole plants of Scoparia dulcis (EESD). For this purpose, the whole plants of S. dulcis were extracted with ethanol following maceration process and tested for the presence of phytochemical constituents. The sedative and hypnotic activity were then investigated using hole cross, open field, hole-board, rota-rod, and thiopental sodium-induced sleeping time determination tests in mice at the doses of 50, 100, and 200 mg/kg of EESD. Diazepam at the dose of 1 mg/kg was used as a reference drug in all the experiments. We found that EESD produced a significant dose-dependent inhibition of locomotor activity of mice both in hole cross and open field tests (P < 0.05). Besides, it also decreased rota-rod performances and the number of head dips in hole-board test. Furthermore, EESD significantly decreased the induction time to sleep and prolonged the duration of sleeping, induced by thiopental sodium. Taken together, our study suggests that EESD may possess sedative principles with potent hypnotic properties.