Antidepressant-like effect of carvacrol (5-Isopropyl-2-methylphenol) in mice: involvement of dopaminergic system

Carvacrol (5-isopropyl-2-methylphenol) is a monoterpenic phenol present in the essential oil of many plants. It is the major component of the essential oil fraction of oregano and thyme. In this study, the effect of carvacrol was investigated in two behavioral models, the forced swimming and tail suspension tests in mice, to investigate the possible antidepressant effect of this substance. Additionally, the mechanisms involved in the antidepressant-like effect of carvacrol in mice were also assessed. Carvacrol (cvc) was administered orally at single doses of 12.5, 25 and 50 mg/kg. The acute treatment of cvc decreased the immobility time in the forced swimming and tail suspension tests without accompanying changes in ambulation in the open-field test. The anti-immobility effect of carvacrol (25 mg/kg) was not prevented by pretreatment of mice with p-chlorophenylalanine, prazosin and yohimbine. On the other hand, the pretreatment of mice with SCH23390 or sulpiride completely blocked the antidepressant-like effect of carvacrol (25 mg/kg) in the forced swimming test. These results show that carvacrol presents antidepressant effects in the forced swimming and tail suspension tests; this effect seems to be dependent on its interaction with the dopaminergic system, but not with the serotonergic and noradrenergic systems. Keywords: Carvacrol; Antidepressant; Forced swimming; Tail suspension; Dopaminergic system.