Effect of cysteine derivatives administration in healthy men exposed to intense resistance exercise by evaluation of pro-antioxidant ratio

J Physiol Sci. 2007 Dec;57(6):343-8. doi: 10.2170/physiolsci.RP009307. Epub 2007 Nov 15.


The aim of this study was to ascertain the influence of cysteine derivatives on pro-antioxidant equilibrium and to compare the antioxidant effectiveness of N-acetylcysteine, alpha-lipoic acid, and taurine by using Loverro's coefficient (pro-antioxidant ratio) in healthy men exposed to intensity-resistance exercise. Fifty-five men were randomly assigned to one of four groups: control (CON, placebo), N-acetylcysteine (NAC 1.8 g.day(-1), 3 days), alpha-lipoic acid (LIP 1.2 g.day(-1), 3 days), or taurine (TAU 3 g.day(-1), 3 days). The erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities, lipid peroxidation products (TBARS), and plasma protein thiol concentrations were evaluated. The P/A ratio was determined from the mean values of TBARS, SOD, GPx, and CAT. The applied exercise at maximal intensity induced the significant changes in pro-antioxidant equilibrium toward peroxidation, which was proved by a 25% increase in TBARS concentration in the CON group. The peroxidation was significantly diminished by NAC (-14%) and LIP (-16%), whereas TAU had no effect on the TBARS concentration. Cysteine derivatives administration prevented exercise-induced decline in SOD activity and increased in GPx activity during exercise. CAT activity changed only in the LIP group. The estimation of P/A ratio showed the lowest level of pro-antioxidant equilibrium after LIP administration. In the CON group, P/A ratio was directly correlated with the protein thiols level (r = 0.495, p < 0.001). These data confirm the antioxidant action of tested cysteine derivatives, particularly lipoic acid, and demonstrate the practical application of P/A ratio to evaluate the effectiveness of antioxidants in athletes.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Acetylcysteine / administration & dosage
  • Acetylcysteine / pharmacology*
  • Administration, Oral
  • Adult
  • Antioxidants / administration & dosage
  • Antioxidants / metabolism*
  • Antioxidants / pharmacology*
  • Catalase / blood
  • Catalase / metabolism
  • Exercise / physiology*
  • Glutathione Peroxidase / metabolism
  • Health
  • Humans
  • Male
  • Oxidative Stress / drug effects
  • Superoxide Dismutase / metabolism
  • Taurine / administration & dosage
  • Taurine / pharmacology*
  • Thiobarbituric Acid Reactive Substances / metabolism
  • Thioctic Acid / administration & dosage
  • Thioctic Acid / pharmacology*
  • Time Factors


  • Antioxidants
  • Thiobarbituric Acid Reactive Substances
  • Taurine
  • Thioctic Acid
  • Catalase
  • Glutathione Peroxidase
  • Superoxide Dismutase
  • Acetylcysteine