title: Protective effects of grape seed proanthocyanidins against oxidative stress induced by lipopolysaccharides of periodontopathogens.
abstract: BACKGROUND
  During phagocytosis or stimulation with bacterial components, macrophages activate various cell processes, including the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are critical for successful defense against invading organisms. Increased levels of ROS/RNS create oxidative stress that results in tissue and bone destruction. Grape seed proanthocyanidins have been reported to possess a wide range of biologic properties against oxidative stress. In the present study, we investigated the effects of a grape seed proanthocyanidin extract (GSE) and commercial polyphenols on the production of ROS and RNS and on the protein expression of inducible nitric oxide synthase (iNOS) by murine macrophages stimulated with lipopolysaccharides (LPS) of periodontopathogens.
  
  
  METHODS
  Macrophages (RAW 264.7) were treated with non-toxic concentrations of either GSE or commercial polyphenols (gallic acid [GA] and [-]-epigallocatechin-3-gallate [EGCG]) and stimulated with LPS of Actinobacillus actinomycetemcomitans or Fusobacterium nucleatum, and iNOS expression was evaluated by immunoblotting. Nitric oxide (NO) production was quantified using the colorimetric Griess assay, whereas ROS production was measured with the fluorescent 123-dihydrorhodamine dye.
  
  
  RESULTS
  GSE strongly decreased NO and ROS production and iNOS expression by LPS-stimulated macrophages. GA also revealed a strong inhibitory effect on NO production without affecting iNOS expression but slightly increasing ROS production. EGCG showed an inhibitory effect on NO and ROS production and on iNOS expression by macrophages.
  
  
  CONCLUSIONS
  Our findings demonstrate that proanthocyanidins have potent antioxidant properties and should be considered a potential agent in the prevention of periodontal diseases.
authors.affiliation: Research Group in Oral Ecology, Faculty of Dentistry, Laval University, Québec City, QC, Canada.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Houde
authors.forename: Daniel
authors.initials: D
authors.lastname: Grenier
authors.forename: Fatiha
authors.initials: F
authors.lastname: Chandad
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000737:chemistry; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D016967:Fusobacterium nucleatum / Q000737:chemistry; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008264:Macrophages; D051379:Mice; D009569:Nitric Oxide / Q000037:antagonists & inhibitors; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors; D018384:Oxidative Stress / Q000187:drug effects*; D010636:Phenols / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D059808:Polyphenols; D044945:Proanthocyanidins / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors; D012639:Seeds; D027843:Vitis
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D005419:Flavonoids; D008070:Lipopolysaccharides; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D044945:Proanthocyanidins; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II