AA does not generate H₂O₂ in human plasma and the generation of H₂O₂ in plasma is dependent on the presence of free transition metal ions. Incubation of freshly isolated human plasma with increasing concentrations of AA. (A) The amount of H₂O₂ generated was determined by Amplex red. As a positive control, 100 μM AA was incubated in IMDM (last bar). (B) The generation of H₂O₂ was determined in human plasma incubated with 100 μM AA and increasing concentrations of CuCl₂. (A-B) Experiments were performed in triplicate and are expressed as the mean ± SD of 2 independent experiments.