Inhibitory effect of plant phenolics on fMLP-induced intracellular calcium rise and chemiluminescence of human polymorphonuclear leukocytes and their chemotactic activity in vitro. (November 2015)

• Record Type: Journal Article
• Authors: Nowak, Piotr Jan; Zasowska-Nowak, Anna; Bialasiewicz, Piotr; de Graft-Johnson, Jeffrey; Nowak, Dariusz; Nowicki, Michal
• Is Part Of: Pharmaceutical biology. Volume 53:Number 11(2015:Nov.)
• Page Start: 1661
• Page End: 1670
• Publication Date: 2015-11
• Subjects: Pharmacognosy -- Periodicals; Materia medica, Vegetable -- Periodicals; 615.321
• DOI: 10.3109/13880209.2014.1001403
• Languages: English
• ISSNs: 1388-0209

Abstract

<abstract> <title>Abstract</title> <p> <italic>Context</italic>: 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.</p> <p> <italic>Objective</italic>: The objective of this study was to examine the <italic>in vitro</italic> effect of each of the 14 polyphenols on PMNs chemotaxis, intracellular calcium response, oxidants production.</p> <p> <italic>Materials and methods</italic>: 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<sup>2+</sup>]<italic><sub>i</sub></italic>) 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.</p> <p> <italic>Results</italic>: Polyphenols had no effect on resting [Ca<sup>2+</sup>]<italic><sub>i</sub></italic>. Unaffected by other compounds, fMLP-dependent increase of [Ca<sup>2+</sup>]<italic><sub>i</sub></italic> was inhibited by quercetin and catechol (5 µM) by 32 ± 14 and 12 ± 10% (<italic>p</italic> < 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% (<italic>p</italic> < 0.05), respectively. 3, 4-Dihydroxyhydrocinnamic, 3, 4-dihydroxyphenylacetic, 4-hydroxybenzoic acid, and catechin (5 µM) revealed distinct (<italic>p</italic> < 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.</p> <p> <italic>Conclusion and discussion</italic>: 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<sup>2+</sup>]<italic><sub>i</sub></italic> response.</p> </abstract>