Evidence of variations of endogenous halogenated volatile organic compounds in alveolar breath after mental exercise-induced oxidative stress

Background. - The effect of oxygen on markers of oxidative stress has not been totally elucidated because previous studies have yielded conflicting results. Methods. - A method for the collection and gas chromatography-mass spectrometry of the halogenated volatile organic compounds in human alveolar breath is described. A transportable apparatus sampled specifically alveolar breath; the volatile organic compounds were captured in a thermal desorption tube, Carbotrap 200 (R). The sample was thermally desorbed from the trap in an automated gas chromatography with mass spectrometry detection and peak fragmentation. Compounds were identified by reference to a computer-based library of mass spectra. Results. - Trichlorotrifluoroethane, tetrafluoroethane, dichlorodifluoromethane were identified in alveolar breath of healthy volunteers after mental exercise-induced oxidative stress. The effects of halogenated alkanes were investigated on electron transport chain activity. These agents impaired the NADH oxidation suggesting an inhibition of the complex I (NADH: ubiquinone oxidoreductase) of the electron transport chain. These inhibitory effects are suspected likely to fight against oxidative stress deleterious reactions. Conclusion. - Chemical inhibition of the oxidative burst in human body trough these halogenated inhibitors is a new concept of significant practical, medical, biological and scientific interest. (C) 2019 Published by Elsevier Masson SAS on behalf of Academie Nationale de Pharmacie.