Drug Res (Stuttg) 2015; 65(04): 205-213
DOI: 10.1055/s-0034-1376963
Original Article
© Georg Thieme Verlag KG Stuttgart · New York

Antidepressant and Anxiolytic Effects of the Methanol Root Extract of Capparis thonningii: Involvement of Monoaminergic, Cholinergic and GABAergic Systems

I. O. Ishola
1   Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, ­University of Lagos, Idi-Araba, Lagos, Nigeria
,
S. O. Olayemi
1   Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, ­University of Lagos, Idi-Araba, Lagos, Nigeria
,
O. K. Yemitan
2   Department of Pharmacology, Faculty of Basic Medical Sciences, Lagos State University College of Medicine, Lagos State, Nigeria
,
E. A. Umeh
1   Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, ­University of Lagos, Idi-Araba, Lagos, Nigeria
› Author Affiliations
Further Information

Publication History

received 07 February 2014

accepted 30 May 2014

Publication Date:
02 June 2014 (online)

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Abstract

Background: Capparis thonningii Schum. (Capparaceae) is used in traditional African Medicine for the treatment of mood disorders.

Objective: The study investigates antidepressant and anxiolytic activities of methanol root extract of C. thonningii (CT).

Methods: CT (25–100 mg/kg, p. o.) was administered 1 h before behavioral studies were carried out in mice. Antidepressant effect was investigated using the forced swimming test (FST) and tail suspension test (TST). The anxiolytic effect was evaluated using the elevated-plus maze test (EPM), hole-board test (HBT), and light-dark test.

Results: CT (25 and 50 mg/kg) increased swimming activity (P<0.05) by 92.73% and attenuated immobility time by 35.72%, similar to anti-immobility effect of imipramine (33.87%) in FST. In addition, CT (50 mg/kg) significantly (P<0.01) reduced immobility time by 30.24% in TST. ­However, the antidepressant-like effect elicited by CT was reversed by metergoline, cyproheptadine, and sulpiride (40.81, 45.93, and 48.52%, respectively) pretreatment but prazosin, and yohimbine failed to reverse this antidepressant-like effect. Similar to diazepam, CT (25 mg/kg) increased duration of open arms exploration (P<0.05) by 43.73% in EPM, number of head-dips (HBT) (90.32%), and time spent in the light compartment by 45.77% in light/dark test indicating anxiolytic-like effect. The anxiolytic-like effect of CT was reversed by flumazenil pretreatment.

Conclusion: The findings from this study suggest antidepressant-like effect of C. thonningii involving interaction with serotonergic (5-HT2), dopaminergic (D2), noradrenergic (α1 and α2), and muscarinic cholinergic systems; and anxiolytic effect through an interaction with GABAA benzodiazepine receptor.