title: Antidepressant-like action of the hydromethanolic flower extract of Tagetes erecta L. in mice and its possible mechanism of action.
abstract: OBJECTIVE
  Tagetes erecta, the marigold, has commercial and ethnomedicinal use; however, reports concerning its efficacy for the treatment of depression are lacking. This study was carried out to elucidate the antidepressant effect of hydromethanolic flower extract of T. erecta.
  
  
  METHODS
  Hydromethanolic extract of flowers of Tagetes erecta was subjected to preliminary phytochemical screening. The extract (12.5, 25, and 50 mg/kg, i.p.) was evaluated for antidepressant effect using forced swim test in mice. The mechanism of antidepressant action was further examined using different drugs and imipramine was used as standard drug.
  
  
  RESULTS
  T. erecta significantly inhibited the immobility period in forced swim test in mice P<0.05). T. erecta (25 mg/kg, i.p.) enhanced the anti-immobility effect of antidepressant drugs like imipramine, fluoxetine, and p-chlorophenylalanine, an inhibitor of serotonin synthesis significantly attenuated its antidepressant effect. The antidepressant effect of T. erecta in the forced swim test was prevented by pretreatment with L-arginine and sildenafil, whereas pretreatment of mice with nitric oxide synthase inhibitors potentiated the action. Pentazocine, a high-affinity sigma receptor agonist, produced synergism with effective dose of T. erecta while progesterone, a sigma receptor antagonist, reversed the antidepressant effect of T. erecta. However, the locomotor activity was not affected at tested doses.
  
  
  CONCLUSIONS
  Serotonergic, nitrergic pathway, and sigma receptors are possibly involved in mediating antidepressant action of T. erecta in mouse forced swim test.
authors.affiliation: Department of Pharmaceutical Sciences, Kumaun University, Nainital, Uttarakhand, India.
authors.forename: Aarti
authors.initials: A
authors.lastname: Khulbe
authors.forename: Savita
authors.initials: S
authors.lastname: Pandey
authors.forename: Sangeeta Pilkhwal
authors.initials: SP
authors.lastname: Sah
mesh_terms: D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001120:Arginine / Q000494:pharmacology; D010134:Fenclonine / Q000494:pharmacology; D035264:Flowers; D005473:Fluoxetine / Q000494:pharmacology; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D000432:Methanol / Q000737:chemistry; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010423:Pentazocine / Q000494:pharmacology; D058986:Phosphodiesterase 5 Inhibitors / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology; D011687:Purines / Q000494:pharmacology; D017480:Receptors, sigma / Q000819:agonists / Q000037:antagonists & inhibitors; D012702:Serotonin Antagonists / Q000494:pharmacology; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000494:pharmacology; D031686:Tagetes; D014867:Water / Q000737:chemistry
chemical_list: D018759:Adrenergic Uptake Inhibitors; D000928:Antidepressive Agents; D001120:Arginine; D010134:Fenclonine; D005473:Fluoxetine; D007099:Imipramine; D000432:Methanol; D019331:NG-Nitroarginine Methyl Ester; D019001:Nitric Oxide Synthase; D010423:Pentazocine; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D010936:Plant Extracts; D011374:Progesterone; D011687:Purines; D017480:Receptors, sigma; D012702:Serotonin Antagonists; D017367:Selective Serotonin Reuptake Inhibitors; D000068677:Sildenafil Citrate; D013450:Sulfones; D014867:Water
keywords: Antidepressant; Tagetes erecta; forced swim test; nitric oxide pathway; serotonergic pathway; sigma receptors