Effects of Costus afer Extract in Mouse Models of Anxiety and Depression and Its Possible Mechanisms of Action

doi.org/10.26538/tjnpr/v6i4.30

Abstract

Costus afer (Costaceae) is a perennial rhizomatous plant found in tropical Africa. It is used in traditional medicine to treat central nervous system disorders. The study investigated the anxiolytic- and antidepressant-like effects of the hydroethanol leaf extract of Costus afer and its possible mechanism(s) of action in mice. C. afer (25-200 mg/kg, p.o.), distilled water (10 mL/kg, p.o.), diazepam (1 and 3 mg/kg, p.o.) and imipramine (20 mg/kg, p.o.) were given 1 h before various tests, including hole-board, open field, elevated plus maze, light/dark exploration (anxiolytic-like activity), forced swim (FST) and tail suspension (TST) (antidepressant-like effect) tests. C. afer (50-200 mg/kg) increased number of head dips (hole-board test; p < 0.05), entries and dips in open arms (elevated plus maze test; p < 0.05-0.001), general square crossings (open field test; p < 0.05) and decreased time spent in the dark box (light/dark exploration test; p < 0.05). C. afer, with peak effect observed at 200 mg/kg, increased (p < 0.01) the latency of immobility and decreased (p < 0.001) the duration of immobility in both FST and TST. Sulpiride (dopamine D2 receptor antagonist, 50 mg/kg), prazosin (α1-adrenoceptor antagonist, 1 µg/kg) and metergoline (5-HT2 receptor antagonist, 4 mg/kg) significantly (p < 0.05-0.01) blocked the anti-immobility effect of C. afer in FST. Findings showed that C. afer possess anxiolytic- and antidepressant-like activities, possibly mediated by α1-adrenergic, dopamine D2 and 5-HT2 receptors.