@article {11579,
	title = {Thiol-based antioxidant supplementation alters human skeletal muscle signaling and attenuates its inflammatory response and recovery after intense eccentric exercise.},
	journal = {Am J Clin Nutr},
	volume = {98},
	year = {2013},
	month = {2013 Jul},
	pages = {233-45},
	abstract = {BACKGROUND: The major thiol-disulfide couple of reduced glutathione (GSH) and oxidized glutathione is a key regulator of major transcriptional pathways regulating aseptic inflammation and recovery of skeletal muscle after aseptic injury. Antioxidant supplementation may hamper exercise-induced cellular adaptations.

OBJECTIVE: The objective was to examine how thiol-based antioxidant supplementation affects skeletal muscle{\textquoteright}s performance and redox-sensitive signaling during the inflammatory and repair phases associated with exercise-induced microtrauma.

DESIGN: In a double-blind, crossover design, 10 men received placebo or N-acetylcysteine (NAC; 20 mg {\textperiodcentered} kg(-1) {\textperiodcentered} d(-1)) after muscle-damaging exercise (300 eccentric contractions). In each trial, muscle performance was measured at baseline, after exercise, 2 h after exercise, and daily for 8 consecutive days. Muscle biopsy samples from vastus lateralis and blood samples were collected before exercise and 2 h, 2 d, and 8 d after exercise.

RESULTS: NAC attenuated the elevation of inflammatory markers of muscle damage (creatine kinase activity, C-reactive protein, proinflammatory cytokines), nuclear factor κB phosphorylation, and the decrease in strength during the first 2 d of recovery. NAC also blunted the increase in phosphorylation of protein kinase B, mammalian target of rapamycin, p70 ribosomal S6 kinase, ribosomal protein S6, and mitogen activated protein kinase p38 at 2 and 8 d after exercise. NAC also abolished the increase in myogenic determination factor and reduced tumor necrosis factor-α 8 d after exercise. Performance was completely recovered only in the placebo group.

CONCLUSION: Although thiol-based antioxidant supplementation enhances GSH availability in skeletal muscle, it disrupts the skeletal muscle inflammatory response and repair capability, potentially because of a blunted activation of redox-sensitive signaling pathways. This trial was registered at clinicaltrials.gov as NCT01778309.},
	keywords = {Acetylcysteine, Adaptation, Physiological, Adult, Antioxidants, Biomarkers, C-Reactive Protein, Creatine kinase, Cross-Over Studies, Cytokines, Diet, Dietary Supplements, Double-Blind Method, Exercise, glutathione, Humans, Immunohistochemistry, Inflammation, Male, Muscle Contraction, NF-kappa B, p38 Mitogen-Activated Protein Kinases, Phosphorylation, Proto-Oncogene Proteins c-akt, Quadriceps Muscle, Ribosomal Protein S6, Ribosomal Protein S6 Kinases, 70-kDa, signal transduction, Sulfhydryl Compounds, Tumor Necrosis Factor-alpha, Young Adult},
	issn = {1938-3207},
	doi = {10.3945/ajcn.112.049163},
	author = {Michailidis, Yannis and Karagounis, Leonidas G and Terzis, Gerasimos and Jamurtas, Athanasios Z and Spengos, Kontantinos and Tsoukas, Dimitrios and Chatzinikolaou, Athanasios and Mandalidis, Dimitrios and Stefanetti, Renae J and Papassotiriou, Ioannis and Athanasopoulos, Spyros and Hawley, John A and Russell, Aaron P and Fatouros, Ioannis G}
}
