Study of the effect of extract of Thymus vulgaris on anxiety in male rats.

There is some evidence in traditional medicine for the effectiveness of Thymus vulgaris ( bǎi lǐ xiāng) in the treatment of anxiety in humans. The elevated plus-maze (EPM) has broadly been used to investigate anxiolytic and anxiogenic compounds. The present study investigated the effects of extract of T. vulgaris on rat behavior in the EPM. In the present study, the data were obtained from male Wistar rats. Animals were divided into four groups: saline group and T. vulgaris groups (50 mg/kg, 100 mg/kg, and 200 mg/kg infusion for 7 days by feeding). During the test period, the total distance covered by animals, the number of open- and closed-arm entries, and the time spent in open and closed arms of the EPM were recorded. T. vulgaris increased open-arm exploration and open-arm entry in the EPM, whereas extract of this plant has no effects on the total distance covered by animals and the number of closed-arm entries. The results of the present experiment indicate that T. vulgaris may have an anxiolytic profile in rat behavior in the EPM test, which is not influenced by the locomotor activity. Further research is required to determine the mechanisms by which T. vulgaris extract exerts an anxiolytic effect in rats.