title: Analgesic and anti-inflammatory activities of Piper nigrum L.
abstract: OBJECTIVE
  To evaluate and compare the analgesic and anti-inflammatory activity of pure compound, piperine along with hexane and ethanol extracts of Piper nigrum L. fruit in mice and rats.
  
  
  METHODS
  The analgesic activity was determined by tail immersion method, analgesy-meter, hot plate and acetic acid induced writhing test. While the anti-inflammatory activity was evaluated by carrageenan-induced paw inflammation in rats.
  
  
  RESULTS
  Piperine at a dose of 5 mg/kg and ethanol extract at a dose of 15 mg/kg after 120 min and hexane extract at a dose of 10 mg/kg after 60 min exhibited significant (P<0.05) analgesic activity by tail immersion method, in comparison to ethanol extract at a dose of 10 mg/kg using analgesy-meter in rats. However, with hotplate method, piperine produced significant (P<0.05) analgesic activity at lower doses (5 and 10 mg/kg) after 120 min. A similar analgesic activity was noted with hexane extract at 15 mg/kg. However, in writhing test, ethanol extract significantly (P<0.05) stopped the number of writhes at a dose of 15 mg/kg, while piperine at a dose of 10 mg/kg completely terminated the writhes in mice. In the evaluation of anti-inflammatory effect using plethysmometer, piperine at doses of 10 and 15 mg/kg started producing anti-inflammatory effect after 30 min, which lasted till 60 min, whereas hexane and ethanol extracts also produced a similar activity at a slightly low dose (10 mg/kg) but lasted for 120 min.
  
  
  CONCLUSIONS
  It is concluded from the present study that Piper nigrum L possesses potent analgesic and anti-inflammatory activities.
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, University of Karachi, Karachi, Pakistan.
authors.forename: Farhana
authors.initials: F
authors.lastname: Tasleem
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, University of Karachi, Karachi, Pakistan.
authors.forename: Iqbal
authors.initials: I
authors.lastname: Azhar
authors.affiliation: Department of Chemistry, University of Karachi, Karachi, Pakistan.
authors.forename: Syed Nawazish
authors.initials: SN
authors.lastname: Ali
authors.affiliation: Department of Chemistry, University of Karachi, Karachi, Pakistan.
authors.forename: Shaista
authors.initials: S
authors.lastname: Perveen
authors.affiliation: Colorcon Limited, Crossways, Victory Way, Kent, Dartford, England. Electronic address: zmahmood@colorcon.com.
authors.forename: Zafar Alam
authors.initials: ZA
authors.lastname: Mahmood
keywords: Acetic acid; Analgesic activity; Anti-inflammatory activity; Carrageenan; Piper nigrum Linnacus