Nitroxide radical TEMPO reduces ozone-induced chemokine IL-8 production in lung epithelial cells

Exposure to high levels of ozone (O3) damages respiratory tract epithelial cells. This research evaluated the ability of TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl), a stable nitroxide free radical, to decrease O3-mediated injury to a respiratory tract-derived cell line (A549 cells) by monitoring in this cell system the interleukine-8 (IL-8) production. TEMPO reduced O3-induced IL-8 production in A549 cells, as evidenced by PCR analysis, Western blot and ELISA assays. This behaviour is explainable on the basis of the reactivity between TEMPO with O3 and/or O3-derived free radicals in biological systems. The study provides evidence that TEMPO reacts with O3 and/or its cytotoxic products and may provide protections against O3-induced biotoxicities.