Evaluation of the Anxiolytic Effect of Vitex agnus-castus on Female Mice and Possible Role of Estrogen Receptors

Vitex agnus-castus is a source of phytoestrogens and is used traditionally in the treatment of premenstrual syndrome. The beneficial effects of phytoestrogens on anxiety have been shown in some studies. In this research, we aimed to evaluate the anxiolytic activity of hydroalcoholic V. agnus-castus extract in animal models. For analyzing the antianxiety effects of the extracts, the elevated plus-maze test was applied. Thirty minutes before the test, different doses of V. agnus-castus (25, 50, and 100 mg/kg) were administered to mice. Diazepam and saline were used as the positive and negative controls, respectively. Tamoxifen was used as an antagonist of estrogen receptors to clarify the role of estrogen. The time spent in the open arms increased at all doses of V. agnus-castus, while entries to closed arms reduced than the controls. Groups which received tamoxifen or a combination of tamoxifen with a high dose of V. angus-castus did not show any anti-anxiety effects. V. agnus-castus extract exhibited anti-anxiety effects and can be used in the treatment of the anxiety behaviors. Phytoestrogens from V. agnus-castus interact with estrogen receptors, which may be the underlying mechanism of its anxiolytic activity.