Evaluation of anxiolytic and sedative effect of essential oil and hydroalcoholic extract of Ocimum basilicum L. and chemical composition of its essential oil.

Ocimum basilicum belongs to Lamiaceae family and has been used for the treatment of wide range of diseases in traditional medicine in Iranian folk medicine. Due to the progressive need to anti-anxiety medications and because of the similarity between O. basilicum and Salvia officinalis, which has anti-anxiety effects, we decided to investigate the anxiolytic and sedative activity of hydroalcoholic extract and essential oil of O. basilicum in mice by utilizing an elevated plus maze and locomotor activity meter. The chemical composition of the plant essential oil was also determined. The essential oil and hydroalcoholic extract of this plant were administered intraperitoneally to male Syrian mice at various doses (100, 150 and 200 mg/kg of hydroalcoholic extract and 200 mg/kg of essential oil) 30 min before starting the experiment. The amount of hydroalcoholic extract was 18.6% w/w and the essential oil was 0.34% v/w. The major components of the essential oil were methyl chavicol (42.8%), geranial (13.0%), neral (12.2%) and β-caryophyllene (7.2%). HE at 150 and 200 mg/kg and EO at 200 mg/kg significantly increased the time passed in open arms in comparison to control group. This finding was not significant for the dose of 100 mg/kg of the extract. None of the dosages had significant effect on the number of entrance to the open arms. Moreover, both the hydroalcoholic extract and the essential oil decreased the locomotion of mice in comparison to the control group. This study shows the anxiolytic and sedative effect of hydroalcoholic extract and essential oil of O. basilicum. The anti-anxiety and sedative effect of essential oil was higher than the hydroalcoholic extract with the same doses. These effects could be due to the phenol components of O. basilicum.