title: Investigations on anti-inflammatory and analgesic activities of Alnus nitida Spach (Endl). stem bark in Sprague Dawley rats.
abstract: BACKGROUND
  Stem bark of Alnus nitida (Spach) Endl. (family Betulaceae) is used by local communities in northern areas of Pakistan as a remedy for swelling, injuries and pain. However no pharmacological study of this plant has been reported to confirm these activities. In this study anti-inflammatory and analgesic effect of A. nitida stem bark have been evaluated.
  
  
  METHODS
  Powder of the stem bark of A. nitida was extracted with methanol (ANBM) and partitioned in escalating polarity to get the n-hexane (ANBH), chloroform (ANBC), ethyl acetate (ANBE) and the residual soluble aqueous (ANBA) fractions. The methanol extract and derived fractions were evaluated for anti-inflammatory activity by using in vitro heat induced albumin denaturation assay and various in vivo assays; carrageenan-induced hind paw edema method, Freunds' complete adjuvant induced arthritis, histamine induced paw edema and xylene induced ear edema in Sprague Dawley rat. The extracts/fractions were also evaluated for analgesic effects by using hot plate analgesic test and acetic acid induced writhing test in rat. The ANBM composition was analyzed by HPLC-DAD and GC-MS analysis.
  
  
  RESULTS
  Results of heat induced albumin denaturation activity indicated that among the extract/fractions ANBC at concentration range of 100-500µg/ml remarkably protected the heat induced albumin denaturation. The pretreatment with ANBC significantly reduced the carrageenan induced edema with 90.81±1.6% after 4h, comparing with 86.63±3.42% reduction produced by the reference drug diclofenac potassium. Histopathological alterations of the gastric and hind paw were decreased with the extract/fractions. Furthermore, anti-inflammatory effects of ANBC were evident in Freunds' complete adjuvant induced arthritis, histamine induced paw edema and xylene induced ear edema. The latency time in hot plate analgesic assay with ANBC (61.59±0.38%) after 90min was comparable to standard drug morphine (69.31±2.67%) and aspirin (67.24±2.08%). Similarly ANBC significantly (p<0.01) inhibited the pain sensation in acetic acid induced writhing test in rat. HPLC-DAD analysis of ANBM indicated the presence of gallic acid, catechin and rutin while the GC-MS analysis of ANBM indicated the presence of 30 compounds predominantly of neophytadiene, 3,7,11,15 tetramethyl-2-hexadecen-1-ol, phytol, vitamin E and linalool.
  
  
  CONCLUSIONS
  The results of this study suggested that the presence of polyphenols, sterols, terpenoids and other constituents might contributed towards the anti-inflammatory and analgesic activities of the crude methanol extract of A. nitida bark and its derived fractions. This study endorsed the folklore use of A. nitida bark for inflammation related disorders.
authors.affiliation: Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: moniba_qau@yahoo.com.
authors.forename: Moniba
authors.initials: M
authors.lastname: Sajid
authors.affiliation: Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: mrkhanqau@yahoo.com.
authors.forename: Muhammad Rashid
authors.initials: MR
authors.lastname: Khan
authors.affiliation: Department of Plant Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: afzaltaxonomist@gmail.com.
authors.forename: Sayed Afzal
authors.initials: SA
authors.lastname: Shah
authors.affiliation: Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: majidpharma808@gmail.com.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Majid
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Gujrat, 50700 Gujrat, Pakistan. Electronic address: hammadismail5@gmail.com.
authors.forename: Hammad
authors.initials: H
authors.lastname: Ismail
authors.affiliation: Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: soniamaryam@bs.qau.edu.pk.
authors.forename: Sonia
authors.initials: S
authors.lastname: Maryam
authors.affiliation: Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: biochemist60@gmail.com.
authors.forename: Riffat
authors.initials: R
authors.lastname: Batool
authors.affiliation: Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: tahirayounis@gmail.com.
authors.forename: Tahira
authors.initials: T
authors.lastname: Younis
mesh_terms: D029661:Alnus / Q000737:chemistry*; D000700:Analgesics / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D008401:Gas Chromatography-Mass Spectrometry; D007249:Inflammation / Q000188:drug therapy / Q000473:pathology; D008297:Male; D008519:Medicine, Traditional / Q000379:methods; D009020:Morphine / Q000494:pharmacology; D010146:Pain / Q000188:drug therapy / Q000473:pathology; D010154:Pakistan; D024301:Plant Bark; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D018547:Plant Stems; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000700:Analgesics; D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D009020:Morphine; D001241:Aspirin
keywords: Alnus nitida; Analgesic; Anti-inflammatory; GC-MS; Hot plate test