title: beta-Amyrin and alpha-amyrin acetate isolated from the stem bark of Alstonia boonei display profound anti-inflammatory activity.
abstract: BACKGROUND
  Alstonia boonei De Wild (Apocyanaceae) is used in ethnomedicine for the management of malaria, ulcer, rhematic pain, toothache, and inflammatory disorders.
  
  
  OBJECTIVE
  To investigate the anti-inflammatory potential of β-amyrin and α-amyrin acetate isolated from the stem bark of Alstonia boonei using animal models.
  
  
  METHODS
  Chromatographic purification of the crude methanol extract led to the isolation and structure elucidation of β-amyrin and α-amyrin acetate. Their anti-inflammatory activities were evaluated in rodents using egg albumen-induced paw edema and xylene-induced ear edema models. The gastric ulcerogenic, in vivo leucocyte migration, and RBC membrane stabilization tests were also investigated.
  
  
  RESULTS
  α-Amyrin acetate at 100 mg/kg showed significant (p < 0.05) inhibition of egg albumen-induced paw edema with % inhibition of 40 at the 5th hour. Oral administration up to 100 mg/kg did not produce significant (p > 0.01) irritation of the gastric mucosa while significant (p < 0.01) ulceration was recorded for indomethacin at 40 mg/kg compared with the negative control. At 100 μg/mL, both β-amyrin and α-amyrin acetate inhibited heat-induced hemolysis to as much 47.2 and 61.5%, respectively, while diclofenac sodium (100 μg/mL) evoked only 40.5% inhibition. Both compounds at 100 µg/ear produced significant (p < 0.01) inhibition of ear edema in mice by 39.4 and 55.5%, respectively. Also at 100 mg/kg (p.o.) α-amyrin acetate evoked 60.3% reduction in total leucocyte count and significant (p < 0.05) suppression (47.9%) of neutrophil infiltration.
  
  
  CONCLUSIONS
  This study generally provided evidence of profound anti-inflammatory activity of β-amyrin and α-amyrin acetate isolated from the Alstonia boonei stem bark.
authors.affiliation: Department of Pure and Industrial Chemistry, Faculty of Physical Sciences, University of Nigeria , Nsukka, Enugu State , Nigeria .
authors.forename: Nkeoma Nkasi
authors.initials: NN
authors.lastname: Okoye
authors.forename: Daniel Lotanna
authors.initials: DL
authors.lastname: Ajaghaku
authors.forename: Henry Nnaemeka
authors.initials: HN
authors.lastname: Okeke
authors.forename: Emmanuel Emeka
authors.initials: EE
authors.lastname: Ilodigwe
authors.forename: Chukwuemeka Sylvester
authors.initials: CS
authors.lastname: Nworu
authors.forename: Festus Basden C
authors.initials: FB
authors.lastname: Okoye
mesh_terms: D031051:Alstonia; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000627:therapeutic use; D004487:Edema / Q000188:drug therapy / Q000473:pathology; D005260:Female; D008297:Male; D051379:Mice; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000627:therapeutic use; D024301:Plant Bark; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification* / Q000627:therapeutic use; D018547:Plant Stems; D051381:Rats
chemical_list: D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D009828:Oleanolic Acid; C000265:beta-amyrin acetate; C036380:beta-amyrin
keywords: Apocyanaceae; egg albumen-induced paw edema; leucocytes migration; pentacyclic triterpene; xylene-induced ear edema