Involvement of serotonergic system in the antidepressant-like effect of hyperoside from apocynum venetum leaves

Abstract

The present study investigated the antidepressant-like effect of hyperoside extracted from Apocynum venetum leaves in mice using the tail suspension test (TST) and forced swimming test (FST). Hyperoside administration at 10, 20 and 30 mg/kg (p.o.) for 10 days reduced immobility time in both tests. This effect is dose-dependent without influencing the animals’ locomotor activity. Additionally, the monoaminergic mechanisms involved in the antidepressant-like effect of hyperoside in the mouse forced swimming test (FST) were evaluated. The results showed that hyperoside produced an antidepressant-like effect in the FST (10-30 mg/kg, i.g.) and in the TST (10–30 mg/kg, i.g.), without accompanying changes in ambulation distance when assessed in the open-field test. The antidepressant-like effect of hyperoside (20 mg/kg, i.g.) was prevented by the pretreatment of mice with ketanserin (5 mg/kg, s.c., a serotonin 5-HT2A receptor antagonist), cyproheptadine (3 mg/kg, i.g., a serotonin 5-HT2 receptor antagonist). On the other hand, the pretreatment of mice with WAY 100635 (0.1 mg/kg, s.c., a serotonin 5-HT1A receptor antagonist) did not block the antidepressant-like effect of hyperoside in the TST. It may be concluded that the hyperoside produces an antidepressant-like effect in the FST and in the TST that is dependent on its interaction with the serotonergic (5-HT2A and 5-HT2 receptors) systems. Taken together, our results suggested that hyperoside deserves further investigation as a putative alternative therapeutic tool that could help the conventional pharmacotherapy of depression.