The aim of the present study was to evaluate hypnotic effect of Coriandrum sativum, Ziziphus jujuba, Lavandula angustifolia and Melissa officinalis hydroalcoholic extracts in mice to select the most effective ones for a combination formula. Three doses of the extracts (250, 500 and 1000 mg/kg of C. sativum and Z. jujuba and 200, 400 and 800 mg/kg of L. angustifolia and M. officinalis) were orally administered to male Swiss mice (20-25 g) and one hour later pentobarbital (50 mg/kg, i.p.) was injected to induce sleep. Onset of sleep and its duration were measured and compared. Control animals and reference group received vehicle (10 ml/kg, p.o.) and diazepam (3 mg/kg, i.p.), respectively. C. sativum and Z. jujuba failed to change sleep parameters. L. angustifolia at doses of 200, 400 and 800 mg/kg shortened sleep onset by 7.6%, 50% and 51.5% and prolonged sleep duration by 9.9%, 43.1% and 80.2%, respectively. Compared with control group the same doses of M. officinalis also decreased sleep onset by 24.7%, 27.5% and 51.2% and prolonged sleep duration by 37.9%, 68.7% and 131.7% respectively. Combinations of L. angustifolia and M. officinalis extracts showed additive effect and it is suggested that a preparation containing both extracts may be useful for insomnia.
Keywords: Coriandrum sativum; Hypnotic; Lavandula angustifolia; Melissa officinalis; Mice; Sleep; Ziziphus jujuba.