title: Psychoneuropharmacological activities and chemical composition of essential oil of fresh fruits of Piper guineense (Piperaceae) in mice.
abstract: BACKGROUND
  Piper guineense Schum & Thonn (Piperaceae) is a medicinal plant used in the Southern States of Nigeria to treat fever, mental disorders and febrile convulsions.
  
  
  OBJECTIVE
  This study aims at determining the chemical composition and the central nervous system (CNS) activities of the essential oil obtained from the plant׳s fresh fruits in order to rationalize its folkloric use.
  
  
  METHODS
  Essential oil of P. guineense (EOPG) obtained by hydrodistillation was analysed by GC/MS. EOPG (50-200mg/kg, i.p.) was evaluated for behavioural, hypothermic, sedative, muscle relaxant, anti-psychotic and anticonvulsant activities using standard procedures.
  
  
  CONCLUSIONS
  Analysis of the oil reveals 44 compounds of which 30 compounds constituting 84.7% were identified. The oil was characterized by sesquiterpenoids (64.4%) while only four monoterpeneoids (21.3%) were found present in the oil. Major compounds identified were β-sesquiphellandrene (20.9%), linalool (6.1%), limonene (5.8%), Z-β-bisabolene (5.4%) and α-pinene (5.3%). The EOPG (50-200mg/kg, i.p.) caused significant (p<0.01) inhibition on rearing {F(4,20)=43}, locomotor {F(4,20)=22} activity and decreased head dips in hole board {F(4,20)=7} indicating CNS depressant effect; decreased rectal temperature {F(4,20)=7-16}, signifying hypothermic activity; decreased ketamine-induced sleep latency {F(4,20)=7.8} and prolonged total sleeping time {F(4,20)=8.8}, indicating sedative effect; reduced muscular tone on the hind-limb grip test {F(4,20)=22}, inclined board {F(4,20)=4-49} and rota rod {F(4,20)=13-106}, implying muscle relaxant activity; induced catalepsy {F(4,20)=47-136}, inhibited apomorphine-induced climbing behaviour {F(4,20)=9} and inhibited apomorphine-induced locomotor {F(4,20)=16}, suggesting anti-psychotic effect; and protected mice against pentylenetetrazole-induced convulsions, indicating anticonvulsant potential.
  
  
  CONCLUSIONS
  The most abundant component of the fresh fruits essential oil of P. guineense was β-sesquiphellandrene (20.9%); and the oil possesses CNS depressant, hypothermic, sedative, muscle relaxant, antipsychotic and anticonvulsant activities, thus providing scientific basis for its ethnomedicinal applications.
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun State 220005, Nigeria; Department of Chemistry and Chemical Technology, Walter Sisulu University, Nelson Mandela Drive Campus, 5117 Mthatha, South Africa. Electronic address: oyemitan@oauife.edu.ng.
authors.forename: Idris Ajayi
authors.initials: IA
authors.lastname: Oyemitan
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun State 220005, Nigeria.
authors.forename: Omotola Aanuoluwa
authors.initials: OA
authors.lastname: Olayera
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun State 220005, Nigeria.
authors.forename: Akeeb
authors.initials: A
authors.lastname: Alabi
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun State 220005, Nigeria.
authors.forename: Luqman Adewale
authors.initials: LA
authors.lastname: Abass
authors.affiliation: Drug Research and Production Unit (DRPU), Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun State 220005, Nigeria.
authors.forename: Christianah Abimbola
authors.initials: CA
authors.lastname: Elusiyan
authors.affiliation: Department of Chemistry and Chemical Technology, Walter Sisulu University, Nelson Mandela Drive Campus, 5117 Mthatha, South Africa.
authors.forename: Adebola Omowumi
authors.initials: AO
authors.lastname: Oyedeji
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun State 220005, Nigeria.
authors.forename: Moses Atanda
authors.initials: MA
authors.lastname: Akanmu
mesh_terms: D000080462:Acyclic Monoterpenes; D000818:Animals; D014151:Anti-Anxiety Agents / Q000737:chemistry / Q000494:pharmacology; D000927:Anticonvulsants / Q000737:chemistry / Q000494:pharmacology; D000081008:Bicyclic Monoterpenes; D001831:Body Temperature / Q000187:drug effects; D002490:Central Nervous System / Q000187:drug effects*; D053138:Cyclohexenes / Q000737:chemistry / Q000494:pharmacology; D020834:Ethnopharmacology / Q000379:methods; D005260:Female; D005638:Fruit / Q000737:chemistry*; D006993:Hypnotics and Sedatives / Q000737:chemistry / Q000494:pharmacology; D000077222:Limonene; D008297:Male; D051379:Mice; D000081222:Monocyclic Sesquiterpenes; D039821:Monoterpenes / Q000737:chemistry / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects; D009822:Oils, Volatile / Q000737:chemistry* / Q000494:pharmacology*; D008517:Phytotherapy / Q000379:methods; D031701:Piper / Q000737:chemistry*; D026321:Piperaceae / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012717:Sesquiterpenes / Q000737:chemistry / Q000494:pharmacology; D012890:Sleep / Q000187:drug effects; D013729:Terpenes / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000080462:Acyclic Monoterpenes; D014151:Anti-Anxiety Agents; D000927:Anticonvulsants; D000081008:Bicyclic Monoterpenes; D053138:Cyclohexenes; D006993:Hypnotics and Sedatives; D000081222:Monocyclic Sesquiterpenes; D039821:Monoterpenes; D009822:Oils, Volatile; D010936:Plant Extracts; D012717:Sesquiterpenes; D013729:Terpenes; D000077222:Limonene; C018584:linalool; C005451:alpha-pinene; C531191:beta-bisabolene
keywords: Anti-psychotic; Anticonvulsant; Behavioural; Piper guineense; Sedative; Volatile oil; β-sesquiphellandrene