Scientific evidence of plant with a rapid-onset and sustained antidepressant effect in a chronic model of depression: Mallotus oppositifolius.

ABSTRACT

BACKGROUND: One of the major drawbacks of current depression pharmacotherapy is the delay in symptom improvement, aside from the untoward side effects and lack of efficacy against refractory depression. This work therefore investigated a possible rapid-onset and sustained antidepressant effect of Mallotus oppositifolius. METHODS: Onset of the antidepressant effect of hydroalcoholic extract from the leaves of M. oppositifolius was investigated using the open space swim test, a chronic depression model. The possible effects of the extract on cognitive dysfunction measured in the Morris water maze and weight gain were also investigated. RESULTS: M. oppositifolius extract, after the first day of treatment, reversed the state of immobility in mice. This effect was sustained even after drug treatment was halted and the antidepressant effect verified in the tail suspension test. The extract also increased the total distance travelled by the mice and reversed the cognitive impairment induced by the depressed state but had no effect on weight variation. CONCLUSIONS: M. oppositifolius exhibits a rapid-onset and sustained antidepressant effect in mice.