title: Contusion injury with chronic in vivo polyphenol supplementation: leukocyte responses.
abstract: BACKGROUND
  In vivo, daily proanthocyanidolic oligomer (PCO) supplementation before and after experimental skeletal muscle contusion injury has been shown to result in a blunted neutrophil response in tissue, quicker macrophage infiltration into muscle, and faster recovery due to a left shift in time course of inflammation. The current study investigated effects of PCO on circulatory neutrophils and macrophage subpopulations as well as in vitro neutrophil migration.
  
  
  METHODS
  Primary cultured neutrophils obtained from control animals were incubated in media with 20% conditioned plasma. To obtain conditioned media, male Wistar rats were supplemented with PCO (20 mg·kg(-1)d(-1)) or placebo (PLA) for 2 wk before a mass-drop contusion injury. Conditioned plasma was prepared from blood collected at different time points after injury (12 h, 1 d, 3 d, and 5 d). Macrophage subpopulation distribution, inflammatory cytokine, and myeloperoxidase levels were assessed for all time points.
  
  
  RESULTS
  On day 1 postinjury, circulating neutrophil numbers were significantly lower in PLA than PCO, suggesting that extravasation from the blood was reduced by PCO. Concurrently, neutrophil migration in vitro was blunted in the presence of conditioned plasma from PCO supplemented rats compared with PLA supplemented rats. Plasma M1 and M2c macrophage numbers differed over time and between groups. M1 macrophage numbers peaked on day 3 with PCO supplementation, followed by a rise in M2c macrophages on day 5, when M1 macrophages numbers were still high in PLA.
  
  
  CONCLUSIONS
  We conclude that PCO supplementation limits neutrophil migration capacity in vitro despite a chemotactic gradient. Furthermore, the earlier appearance of type M2 macrophages suggests a switch to an anti-inflammatory phenotype after injury even in circulation.
authors.affiliation: Department Physiological Sciences, Stellenbosch University, Matieland, SOUTH AFRICA.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Kruger
authors.forename: Kathryn H
authors.initials: KH
authors.lastname: Myburgh
authors.forename: Carine
authors.initials: C
authors.lastname: Smith
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D003288:Contusions / Q000276:immunology*; D017077:Culture Media, Conditioned / Q000494:pharmacology; D019587:Dietary Supplements; D056604:Grape Seed Extract / Q000494:pharmacology*; D016753:Interleukin-10 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007958:Leukocyte Count; D008264:Macrophages / Q000187:drug effects*; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D059808:Polyphenols / Q000494:pharmacology*; D044945:Proanthocyanidins / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D017077:Culture Media, Conditioned; D056604:Grape Seed Extract; C511402:Grape Seed Proanthocyanidins; D015850:Interleukin-6; D059808:Polyphenols; D044945:Proanthocyanidins; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10