title: Involvement of serotonergic system in the antidepressant-like effect of piperine.
abstract: Piperine is a major alkaloid of black pepper (Piper nigrum Linn.) and long pepper (P. longum Linn.), and its antidepressant-like effect has been previously demonstrated. The purpose of this study was to explore the possible contribution of the serotonergic system in the antidepressant-like effect of piperine in mice. The results showed that piperine significantly reduced the immobility time in the forced swim test and tail suspension test in mice. The anti-immobility effect of piperine in the forced swim test and tail suspension test was completely abolished by pre-treating the mice with pCPA (an inhibitor of 5-HT synthesis). Piperine treatment also significantly potentiated the number of head-twitches of mice induced by 5-HTP (a metabolic precursor to 5-HT). In addition, the neurochemical assays showed that piperine produced a marked increase of 5-HT level in both the hippocampus and frontal cortex of mice. Taken together, these results clearly suggest that the antidepressant-like effect of piperine is mediated via the serotonergic system by enhancing 5-HT content in mouse brain.
authors.affiliation: School of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.
authors.forename: Qing-Qiu
authors.initials: QQ
authors.lastname: Mao
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Xian
authors.forename: Siu-Po
authors.initials: SP
authors.lastname: Ip
authors.forename: Chun-Tao
authors.initials: CT
authors.lastname: Che
mesh_terms: D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000470:Alkaloids / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D000928:Antidepressive Agents; D001522:Behavior, Animal / Q000187:drug effects; D052117:Benzodioxoles / Q000494:pharmacology*; D001923:Brain Chemistry / Q000187:drug effects; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D010134:Fenclonine / Q000494:pharmacology; D005473:Fluoxetine / Q000494:pharmacology; D019417:Hindlimb Suspension / Q000523:psychology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010880:Piperidines / Q000494:pharmacology*; D053284:Polyunsaturated Alkamides / Q000494:pharmacology*; D012701:Serotonin / Q000378:metabolism / Q000502:physiology*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D013550:Swimming / Q000523:psychology
chemical_list: D006916:5-Hydroxytryptophan; D000470:Alkaloids; D000928:Antidepressive Agents; D052117:Benzodioxoles; D010134:Fenclonine; D005473:Fluoxetine; D010880:Piperidines; D053284:Polyunsaturated Alkamides; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors; C008922:piperine