title: Inhibitory effects of areca nut extract on expression of complement receptors and fc receptors in human neutrophils.
abstract: BACKGROUND
  Chewing of areca quid increases the prevalence of periodontal diseases. Areca nut extract (ANE) inhibits the phagocytic activity of human neutrophils. This in vitro study investigates the effects of ANE on complement- and antibody-opsonized phagocytosis by neutrophils. Expression of complement receptors, Fc receptors, and F-actin in ANE-treated neutrophils is also analyzed.
  
  
  METHODS
  The viability of ANE-treated neutrophils was determined using the propidium iodide staining method. The possible effects of ANE on the expression of complement receptors and Fc receptors were examined using an immunofluorescence staining method followed by flow cytometry and confocal laser scanning microscopy. The phagocytic activity of neutrophils against complement or immunoglobulin (Ig)G-opsonized fluorescent beads was analyzed using flow cytometry. Expression of F-actin was determined using confocal laser scanning microscopy.
  
  
  RESULTS
  ANE significantly inhibited the production of complement receptors (CR1, CR3, and CR4) and Fc receptors (FcγRII and FcγRIII) in a concentration-dependent manner. Treatment of neutrophils with ANE significantly impaired their ability to phagocytose fluorescent beads. ANE also inhibited phagocytosis of fluorescent beads that were opsonized by complement or IgG. Moreover, expression of F-actin was inhibited after ANE treatment.
  
  
  CONCLUSIONS
  ANE inhibits the complement- and IgG-mediated neutrophil phagocytosis that may result from reduction of the expression of complement receptors, Fc receptors, and F-actin formation after ANE treatment. The findings suggest that areca nut chewing may jeopardize the defensive functions of neutrophils and affect periodontal health.
authors.affiliation: Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ya-Yun
authors.initials: YY
authors.lastname: Lee
authors.forename: Ming-Bin
authors.initials: MB
authors.lastname: Lin
authors.forename: Chi-Fang
authors.initials: CF
authors.lastname: Cheng
authors.forename: Lien-Yu
authors.initials: LY
authors.lastname: Chang
authors.forename: Tsung-Yun
authors.initials: TY
authors.lastname: Liu
authors.forename: Shan-Ling
authors.initials: SL
authors.lastname: Hung
mesh_terms: D000199:Actins / Q000187:drug effects; D000328:Adult; D001114:Areca; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004396:Coloring Agents; D003172:Complement C1 / Q000187:drug effects; D005260:Female; D005434:Flow Cytometry; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D016167:Integrin alphaXbeta2 / Q000187:drug effects; D016177:Macrophage-1 Antigen / Q000187:drug effects; D008297:Male; D018613:Microscopy, Confocal; D008863:Microspheres; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology; D009754:Nuts; D010587:Phagocytosis / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D011419:Propidium; D011951:Receptors, Complement / Q000187:drug effects*; D011961:Receptors, Fc / Q000187:drug effects*; D017452:Receptors, IgG / Q000187:drug effects; D055815:Young Adult
chemical_list: D000199:Actins; D004396:Coloring Agents; D003172:Complement C1; D016167:Integrin alphaXbeta2; D016177:Macrophage-1 Antigen; D010936:Plant Extracts; D011951:Receptors, Complement; D011961:Receptors, Fc; D017452:Receptors, IgG; D011419:Propidium
keywords: Actins; Fc; areca; complement; neutrophils; phagocytosis; receptors