A Comparison of the Anxiolytic and Hypnotic Effects of Origanum majorana Essential Oil and Alprazolam in Male Mice

Abstract

Background and Aim: Previous studies have reported many pharmacological properties for Origanum majorana, including anticonvulsant, analgesic, sedative, and antidepressant-like effects. Given this, the aim of this study was to compare the anxiolytic and hypnotic effects of Origanum majorana essential oil (OMEO) and alprazolam in male mice. Material and Methods: In this experimental study, 60 male NMRI mice were divided into 10 groups of six each. In both of the experiments, negative control groups received vehicle (10 ml/kg) and positive control groups received alprazolam (0.5 mg/kg) and treatment groups received OMEO (10, 20 and 40 mg/kg). For assessing anxiolytic effects, the number of entries and the time spent in the open and closed arms were recorded by using elevated plus maze (EPM). For evaluating hypnotic effects, the onset and duration of the sleep were recorded by using ketamine-induced sleeping time test. One-way ANOVA followed by post hoc Tukey's test were used for statistical analysis. Results: All doses of OMEO and alprazolam, compared to control group, increased the number of entries and the time spent in the open arms and, conversely, reduced the number of entries and the time spent in the closed arms. In addition, all doses of the essential oil similar to alprazolam reduced the onset of sleeping and increased the duration of sleep. Conclusion: The results relieved that the OMEO have anxiolytic and hypnotic effects. However, further studies are needed to determine their exact mechanism of action.

Keywords

• origanum majorana, anxiety, hypnotic effect, elevated plus maze, mice