Effect of therapeutic plasma concentrations of non-steroidal anti-inflammatory drugs on the production of reactive oxygen species by activated rat neutrophils

I.M.M Paino,I.L Brunetti,N.M Khalil,M.P.P Kanegae,L.M Da Fonseca,V.F Ximenes

doi:10.1590/s0100-879x2005000400007

Abstract

The release of reactive oxygen specie (ROS) by activated neutrophil is involved in both the antimicrobial and deleterious effects in chronic inflammation. The objective of the present investigation was to determine the effect of therapeutic plasma concentrations of non-steroidal anti-inflammatory drugs (NSAIDs) on the production of ROS by stimulated rat neutrophils. Diclofenac (3.6 microM), indomethacin (12 microM), naproxen (160 microM), piroxicam (13 microM), and tenoxicam (30 microM) were incubated at 37 masculineC in PBS (10 mM), pH 7.4, for 30 min with rat neutrophils (1 x 10(6) cells/ml) stimulated by phorbol-12-myristate-13-acetate (100 nM). The ROS production was measured by luminol and lucigenin-dependent chemiluminescence. Except for naproxen, NSAIDs reduced ROS production: 58 +/- 2% diclofenac, 90 +/- 2% indomethacin, 33 +/- 3% piroxicam, and 45 +/- 6% tenoxicam (N = 6). For the lucigenin assay, naproxen, piroxicam and tenoxicam were ineffective. For indomethacin the inhibition was 52 +/- 5% and diclofenac showed amplification in the light emission of 181 +/- 60% (N = 6). Using the myeloperoxidase (MPO)/H2O2/luminol system, the effects of NSAIDs on MPO activity were also screened. We found that NSAIDs inhibited both the peroxidation and chlorinating activity of MPO as follows: diclofenac (36 +/- 10, 45 +/- 3%), indomethacin (97 +/- 2, 100 +/- 1%), naproxen (56 +/- 8, 76 +/- 3%), piroxicam (77 +/- 5, 99 +/- 1%), and tenoxicam (90 +/- 2, 100 +/- 1%), respectively (N = 3). These results show that therapeutic levels of NSAIDs are able to suppress the oxygen-dependent antimicrobial or oxidative functions of neutrophils by inhibiting the generation of hypochlorous acid.

Highlights

The innate immune response comprises a series of events which prepare the organism to act against intruding agents
This process, known as oxidative burst, is the result of the assembly of the multi-enzyme NADPH-oxidase system that promotes the one-electron reduction of oxygen to superoxide anion [2]. This species is reduced to hydrogen peroxide in a reaction catalyzed by superoxide dismutase and hydrogen peroxide is used by the enzyme myeloperoxidase (MPO) to oxidize chloride to hypochlorous acid (HOCl) [3,4,5]
Lactate dehydrogenase activity was measured in the extracellular medium when neutrophils were incubated with non-steroidal anti-inflammatory drugs (NSAIDs). aTherapeutic plasma concentration; bten times higher than the therapeutic plasma concentration

Summary

Introduction

The innate immune response comprises a series of events which prepare the organism to act against intruding agents. Non-mitochondrial oxygen uptake is initiated by the PMN, resulting in the production of reactive oxygen species (ROS) This process, known as oxidative burst, is the result of the assembly of the multi-enzyme NADPH-oxidase system that promotes the one-electron reduction of oxygen to superoxide anion [2]. This species is reduced to hydrogen peroxide in a reaction catalyzed by superoxide dismutase and hydrogen peroxide is used by the enzyme myeloperoxidase (MPO) to oxidize chloride to hypochlorous acid (HOCl) [3,4,5] This highly oxidant chemical has been proposed to be the main agent responsible for the antimicrobial action of PMN. Non-steroidal anti-inflammatory drugs (NSAIDs) have been studied in terms of their effect on ROS production since, in addition to having a widely accepted mechanism of action by inhibition of the enzymes involved in the production of proinflammatory lipid-derived mediators, these compounds may interact with the oxidants produced by phagocytic cells [13,14,15,16]

Methods

Results

Conclusion