Anxiolytic Effect of Ocimum basilicum Extract in Rats Tested by Elevated Plus-Maze Task

Background: There are reports in traditional medicine about the effectiveness of Ocimum basilicum (OB) in the treatment of anxiety. The Elevated Plus-Maze (EPM) has been predominantly used to investigate anxiety levels in rodents. Objectives: The purpose of the present study was to investigate the effectiveness of extract of OB on rat behavior in the EPM test. Materials and Methods: Male Wistar rats weighing 220 - 250 g were used in the present study. Forty rats were divided into 4 groups: three OB groups (25, 50, 100 mg/kg oral administration of OB for 7 days) and a saline control group. One day after the last day of feeding, the animals’ behavior in EPM was videotaped for 10 minutes. Then, their behavior scored for formal indexes of anxiety, such as the total distance covered by animals, the percentage of entries into and the time spent in open and closed arms. Results: The results showed that after oral feeding of OB, the percentage of open arms entry and open arms time in EPM increased in the experimental groups. OB extract has no effect on the total distance covered by animals and number of closed arm entries. Conclusions: Our results demonstrated that the extract of OB could induce anxiolytic effect in rats after 1 week oral administration. The effect of OB was not induced through changes in motor activity. Further investigations are necessary for pharmacological providing of OB and better understanding of its anxiolytic properties and neurobiological mechanisms.