Agastache mexicana may produce anxiogenic-like actions in the male rat

Behavioral effects of a water-soluble extract of Agastache mexicana, a plant with purported anxiolytic actions, were studied in male Wistar rats. In the elevated plus-maze test, various doses of the plant extract (3.0 mg/kg body wt.; 9.0 mg/kg body wt.; 12.0 mg/kg body wt.) administered intraperitoneally (i.p.) decreased the exploration of open arms, showing an anxiogenic-like effect. Agastache mexicana (12 mg/kg body wt.; i.p.) did not change immobility in the forced swimming test (i.e., had no anti-depressant effect) but increased the anti-immobility action of 32.0 mg/kg body wt. (i.p.) of desipramine (i.e., increased the antidepressant-like effect of desipramine). A. mexicana had no effect on exploratory activity in an open field test, indicating that it had no sedative effect at the doses used. It is concluded that effects of the water extract of A. mexicana are more consistent with an anxiogenic-like property than an anxiolytic-like one.