Antidepressant-like effect of Tabernaemontana catharinensis hydroalcoholic extract in mice: Evidence of the involvement of 5-HT1A receptors.

Abstract

The Tabernaemontana catharinensis shrub belongs to the Apocynaceae family and has been shown to present several pharmacological effects in studies that used ethanolic or aqueous extracts of the plant. The present study investigated the possible antidepressant activity of Tabernaemontana catharinensis hydroalcoholic extract in the forced swim test in mice. The mechanisms involved in this antidepressant-like effect were also assessed. Tabernaemontana catharinensis extract (1,000 mg/kg, p.o.) decreased immobility time in the forced swim test after acute and chronic treatment. The antiimmobility effect of Tabernaemontana catharinensis extract was not prevented by pretreatment with the 2-adrenoceptor antagonist yohimbine (1 mg/kg, i.p.) or dopamine D1 receptor antagonist SCH 23390 (0.05 mg/kg, s.c.). Conversely, pretreatment with the serotonin 5-hydroxytryptamine-1A (5-HT1A) receptor antagonist NAN-190 (.5 mg/kg, i.p.) completely blocked the antidepressant-like effect of Tabernaemontana catharinensis in the forced swim test. These effects may depend on flavonones, flavononols, xanthones, flavones, and tannins in Tabernaemontana catharinensis .W e hypothesize that these compounds are responsible for the antidepressant-like action of this plant, with involvement of the monoaminergic system. In conclusion, Tabernaemontana catharinensis produces an antidepressant-like effect in the forced swim test.