title: Inhibitory effect of plant phenolics on fMLP-induced intracellular calcium rise and chemiluminescence of human polymorphonuclear leukocytes and their chemotactic activity in vitro.
abstract: BACKGROUND
  Polymorphonuclear leukocytes (PMNs) produce oxidants, contributing to systemic oxidative stress. Diets rich in plant polyphenols seem to decrease the risk of oxidative stress-induced disorders including cardiovascular disease.
  
  
  OBJECTIVE
  The objective of this study was to examine the in vitro effect of each of the 14 polyphenols on PMNs chemotaxis, intracellular calcium response, oxidants production.
  
  
  METHODS
  Blood samples and PMNs suspensions were obtained from 60 healthy non-smoking donors and incubated with a selected polyphenol (0.5-10 µM) or a control solvent. We assessed resting and fMLP-dependent changes of intracellular calcium concentration ([Ca(2+)]i) in PMNs with the Fura-2AM method and measured fMLP-induced luminol enhanced whole blood chemiluminescence (fMLP-LBCL). Polyphenol chemoattractant activity for PMNs was tested with Boyden chambers.
  
  
  RESULTS
  Polyphenols had no effect on resting [Ca(2+)]i. Unaffected by other compounds, fMLP-dependent increase of [Ca(2+)]i was inhibited by quercetin and catechol (5 µM) by 32 ± 14 and 12 ± 10% (p < 0.04), respectively. Seven of the 14 tested substances (5 µM) influenced fMLP-LBCL by decreasing it. Catechol, quercetin, and gallic acid acted most potently reducing fMLP-LBCL by 49 ± 5, 42 ± 15, and 28 ± 18% (p < 0.05), respectively. 3,4-Dihydroxyhydrocinnamic, 3,4-dihydroxyphenylacetic, 4-hydroxybenzoic acid, and catechin (5 µM) revealed distinct (p < 0.02) chemoattractant activity with a chemotactic index of 1.9 ± 0.8, 1.8 ± 0.7, 1.6 ± 0.6, 1.4 ± 0.2, respectively.
  
  
  CONCLUSIONS
  Catechol, quercetin, and gallic acid at concentrations commensurate in human plasma strongly suppressed the oxidative response of PMNs. Regarding quercetin and catechol, this could result from an inhibition of [Ca(2+)]i response.
authors: Department of Nephrology, Hypertension, and Kidney Transplantation, Medical University of Lodz , Lodz , Poland .
authors: Piotr Jan
authors: PJ
authors: Nowak
authors: Anna
authors: A
authors: Zasowska-Nowak
authors: Piotr
authors: P
authors: Bialasiewicz
authors: Jeffrey
authors: J
authors: de Graft-Johnson
authors: Dariusz
authors: D
authors: Nowak
authors: Michal
authors: M
authors: Nowicki
mesh_terms: D000328:Adult; D002118:Calcium / Q000378:metabolism*; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D049449:Luminescence; D008297:Male; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000633:toxicity*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010636:Phenols / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D010636:Phenols; D010936:Plant Extracts; D009240:N-Formylmethionine Leucyl-Phenylalanine; D002118:Calcium
keywords: Antioxidants; chemiluminescence; chemotaxis; intracellular calcium; oxidative burst; polymorphonuclear leukocytes; polyphenols