title: Differential metabolomics for quantitative assessment of oxidative stress with strenuous exercise and nutritional intervention: thiol-specific regulation of cellular metabolism with N-acetyl-L-cysteine pretreatment.
abstract: Despite several decades of active research, the success of large-scale clinical trials involving antioxidants remains equivocal given the complex biological interactions of reactive oxygen/nitrogen species in human health. Herein, we outline a differential metabolomics strategy by capillary electrophoresis-electrospray ionization-mass spectrometry (CE-ESI-MS) to assess the efficacy of nutritional intervention to attenuate oxidative stress induced by strenuous exercise. A healthy volunteer was recruited to perform a submaximal prolonged ergometer cycling trial until volitional exhaustion with frequent blood collection over a 6 h time interval, which included pre-, during, and postexercise periods while at rest. A follow-up study was subsequently performed by the same subject after high-dose oral intake of N-acetyl-L-cysteine (NAC) prior to performing the same exercise protocol under standardized conditions. Time-dependent changes in global metabolism of filtered red blood cell lysates by CE-ESI-MS were measured to reveal a significant attenuation of cellular oxidation associated with high-dose oral NAC intake relative to a control. Untargeted metabolite profiling allowed for the identification and quantification of several putative early- and late-stage biomarkers that reflected oxidative stress inhibition due to nutritional intervention, including oxidized glutathione (GSSG), reduced glutathione (GSH), 3-methylhistidine (3-MeHis), L-carnitine (C0), O-acetyl-L-carnitine (C2), and creatine (Cre). Our work demonstrates the proof-of-principle that NAC pretreatment is effective at dampening acute episodes of oxidative stress by reversible perturbations in global metabolism that can provide deeper insight into the mechanisms of thiol-specific protein inhibition relevant to its successful translation as a prophylaxis in clinical medicine.
authors.affiliation: Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Lee
authors.forename: Daniel
authors.initials: D
authors.lastname: West
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Phillips
authors.forename: Philip
authors.initials: P
authors.lastname: Britz-McKibbin
mesh_terms: D000108:Acetylcarnitine / Q000378:metabolism; D000111:Acetylcysteine / Q000494:pharmacology*; D000284:Administration, Oral; D002331:Carnitine / Q000378:metabolism; D019075:Electrophoresis, Capillary / Q000379:methods*; D015444:Exercise; D005978:Glutathione / Q000378:metabolism; D019803:Glutathione Disulfide / Q000378:metabolism; D006801:Humans; D008297:Male; D055432:Metabolomics / Q000379:methods*; D008762:Methylhistidines / Q000378:metabolism; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D055815:Young Adult
chemical_list: D008762:Methylhistidines; D017382:Reactive Oxygen Species; D000108:Acetylcarnitine; D005978:Glutathione; C028118:3-methylhistidine; D002331:Carnitine; D019803:Glutathione Disulfide; D000111:Acetylcysteine