THE SPIN TRAP 5,5-DIMETHYL-1-PYRROLINE N-OXIDE INHIBITS LIPOPOLYSACCHARIDE-INDUCED INFLAMMATION IN RAW264.7 CELLS

ZILI, ZHAI; SANDRA E. GOMEZ-MEJIBA; HUA, ZHU; FLOREA, LUPU; DARIO C. RAMIREZ

LIFE SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2012 vol. 90 p. 432 - 439

0024-3205

AIM: Exposure of macrophages to lipopolysaccharide (LPS) induces oxidative and inflammatory stresses, which cause cell damage. Antioxidant and anti-inflammatory properties have been attributed to the nitrone spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO), commonly used in free radical analysis, but these aspects of DMPO have been little explored. In this study, we sought to establish the anti-inflammatory activity of DMPO, presumably by removing free radicals which otherwise help activate inflammatory response and damage cells. MAIN METHODS: RAW 264.7 macrophages were treated with LPS and/or DMPO for different time points, cell damage, production of inflammatory mediators, inducible nitric oxide synthase (iNOS) expression, NF-κB p65 activation, phosphorylation of MAPKs and Akt, and intracellular reactive oxygen species (ROS) were determined. KEY FINDINGS: After cells were treated with LPS and/or DMPO for 24 h, DMPO reduced the LPS-induced inflammatory response as indicated by downregulated iNOS expression and production of inflammatory mediators. Accordingly, DMPO protected cells from LPS-induced cytotoxicity. In order to understand the mechanistic basis of these DMPO effects, the NF-κB p65 activation and the phosphorylation of MAPKs and Akt were examined. We found, by assaying cells treated with LPS and/or DMPO for 15-60 min, that DMPO inhibited the phosphorylation of MAPKs, Akt, and IκBα, and reduced the NF-κB p65 translocation. Furthermore, we demonstrated that DMPO inhibited LPS-induced ROS production. SIGNIFICANCE: DMPO showed the anti-inflammatory activity and attenuated LPS-induced cell damage, most likely by reducing ROS production and thus preventing the subsequent inflammatory activation and damage.