Antidepressant activity of extracts of Passiflora foetida in mice and the involvement of D[subscript 1] and 5-HT[subscript 1A] receptors

Abstract

The present study was aimed to investigate the potential antidepressant activity of Passiflora foetida (PF) extracts on the animal model of depression and the possible involvement of dopaminergic (DA) and serotoninergic (5-HT) mechanisms in their antidepressant activity. The acute intraperitoneal (IP) administration of 50 mg/kg PF extracts in mice revealed no CNS stimulant effects as measured by locomotor activity. Antidepressant activity was tested by using a mouse model of depression, the open space swimming test. Subacute IP administration of 50 mg/kg of PF extracts, subfraction PF003-1 and PF003-2, resulted in a significant reduction of the decrease in mobility time of mice. This antidepressant-like effect was comparable to that observed in a classical antidepressant drug, imipramine. Other subfractions of PF did not show apparent antidepressant activity. The involvement of serotoninergic and dopaminergic mechanisms in the antidepressant activityof PF extracts was investigated by using a dopamine D[subscript 1] antagonist, SCH 23390 (0.05 mg/kg, IP) and a serotonin 5-HT[subscript 1A) antagonist, WAY 100635 (0.3 mg/kg, IP). The antidepressant effect of PF extracts, PF003-1 and PF003-2, was markedly abolished by prior IP administration of these antagonists, individually or in combination. Therefore, the results suggested that the antidepressant activity of PF extracts may mediate through dopaminergic and serotoninergic mechanisms in the brain. In conclusion, the present study suggested that PF extracts (subfractions PF003-1 and PF003-2) possessed potential antidepressant effects which could be of therapeutic interest for using in the treatment of patients with depressive disorders.