title: Antidepressant and anxiolytic effects of the methanol root extract of Capparis thonningii: involvement of monoaminergic, cholinergic and GABAergic systems.
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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, -University of Lagos, Idi-Araba, Lagos, Nigeria.
authors.forename: I O
authors.initials: IO
authors.lastname: Ishola
authors.affiliation: Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, -University of Lagos, Idi-Araba, Lagos, Nigeria.
authors.forename: S O
authors.initials: SO
authors.lastname: Olayemi
authors.affiliation: Department of Pharmacology, Faculty of Basic Medical Sciences, Lagos State University College of Medicine, Lagos State, Nigeria.
authors.forename: O K
authors.initials: OK
authors.lastname: Yemitan
authors.affiliation: Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, -University of Lagos, Idi-Araba, Lagos, Nigeria.
authors.forename: E A
authors.initials: EA
authors.lastname: Umeh
mesh_terms: D018674:Adrenergic Antagonists / Q000494:pharmacology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D000928:Antidepressive Agents / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D015306:Biogenic Monoamines / Q000378:metabolism*; D031484:Capparis / Q000737:chemistry*; D018678:Cholinergic Agents / Q000494:pharmacology; D059329:Cholinergic Neurons / Q000187:drug effects* / Q000378:metabolism; D003533:Cyproheptadine / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D005260:Female; D005442:Flumazenil / Q000494:pharmacology; D018682:GABA Agents / Q000494:pharmacology; D046353:Immobility Response, Tonic / Q000187:drug effects; D008297:Male; D008711:Metergoline / Q000494:pharmacology; D000432:Methanol / Q000737:chemistry; D051379:Mice; D018727:Muscarinic Antagonists / Q000494:pharmacology; D010936:Plant Extracts / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry; D011224:Prazosin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D013469:Sulpiride / Q000494:pharmacology; D015016:Yohimbine / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D018674:Adrenergic Antagonists; D014151:Anti-Anxiety Agents; D000928:Antidepressive Agents; D015306:Biogenic Monoamines; D018678:Cholinergic Agents; D018492:Dopamine Antagonists; D018682:GABA Agents; D018727:Muscarinic Antagonists; D010936:Plant Extracts; D012702:Serotonin Antagonists; D008711:Metergoline; D015016:Yohimbine; D003533:Cyproheptadine; D005442:Flumazenil; D005680:gamma-Aminobutyric Acid; D001285:Atropine; D013469:Sulpiride; D011224:Prazosin; D000432:Methanol