title: Antioxidants counteract nicotine and promote migration via RacGTP in oral fibroblast cells.
abstract: BACKGROUND
  Smoking is associated with an increased risk of oral health and dental problems. The aim of this study is to address the hypothesis that nicotine impairs wound healing by increasing reactive oxygen species and inhibiting cell migration, and antioxidants (AOs) may counteract nicotine effects.
  
  
  METHODS
  Primary human gingival fibroblasts (HGFs) and human periodontal ligament (HPDL) fibroblasts were grown to confluence, pretreated with 6 mM nicotine for 2 hours, and treated with AOs in the presence of nicotine. The pure AO compounds ferulic acid (F), phloretin (P), tetrahydrocurcuminoid Cockroft Gault (T), and resveratrol (R) were tested in single, double, or triple combinations (10(-5) M). The migratory behavior at a scratch-wound edge was recorded every 15 minutes for 10 hours by using live-cell imaging. The active form of the Rho-associated protein (Rac) and guanosine triphosphate (GTP) (RacGTP) was immunolabeled and analyzed using confocal microscopy.
  
  
  RESULTS
  Combinations of double and triple AOs had a greater effect than single AOs on migration rates and Rac activation. The triple combinations PFR and RFT clearly and unambiguously counteracted the effects of nicotine and significantly increased migration rates in HGF and HPDL fibroblast.
  
  
  CONCLUSIONS
  Treatment with AO combinations clearly counteracted the effects of nicotine by restoring and increasing cell-migration rates. We found the combination of PFR was the most effective in HGFs, whereas, RFT was the most effective combination in HPDL fibroblast. These results clearly demonstrate that PF, RFT, and PFR counteract the negative effects of nicotine on cultured oral fibroblasts via the RacGTP signal-transduction pathway.
authors.affiliation: Department of Biomedical Sciences, Baylor College of Dentistry, Dallas, TX 75246, USA. ssanmiguel@bcd.tamhsc.edu
authors.forename: Symone M
authors.initials: SM
authors.lastname: San Miguel
authors.forename: Lynne A
authors.initials: LA
authors.lastname: Opperman
authors.forename: Edward P
authors.initials: EP
authors.lastname: Allen
authors.forename: Jan
authors.initials: J
authors.lastname: Zielinski
authors.forename: Kathy K H
authors.initials: KK
authors.lastname: Svoboda
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002465:Cell Movement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003373:Coumaric Acids / Q000494:pharmacology; D003474:Curcumin / Q000031:analogs & derivatives / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects*; D016166:Free Radical Scavengers / Q000494:pharmacology; D005881:Gingiva / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D009538:Nicotine / Q000037:antagonists & inhibitors*; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects*; D010636:Phenols / Q000494:pharmacology; D010693:Phloretin / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors; D000077185:Resveratrol; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors; D015398:Signal Transduction / Q000187:drug effects; D013267:Stilbenes / Q000494:pharmacology; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects; D020744:rac GTP-Binding Proteins / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D003373:Coumaric Acids; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D010636:Phenols; D017382:Reactive Oxygen Species; D013267:Stilbenes; C096277:tetrahydrocurcumin; D009538:Nicotine; C004999:ferulic acid; D012264:Ribonucleotide Reductases; D020744:rac GTP-Binding Proteins; D003474:Curcumin; D000077185:Resveratrol; D010693:Phloretin