Reactive oxygen species (ROS) are not only generated in conditions of cellular stress but are also constitutively produced in most cell types by specific metabolic processes. This research focused on a potential antioxidant Trolox (model compound for alpha-tocopherol), with the aim to establish exact mechanisms of Trolox intracellular oxidation prevention on model organism Saccharomyces cerevisiae. Measuring intracellular oxidation of Trolox-treated yeast cells revealed that Trolox decreased intracellular oxidation during normal metabolism. Trolox treatment decreased cyto- and geno-toxicity of treated yeast cells in MES buffer, lowered intracellular oxidation, decreased intracellular peroxides formation, and increased H(2)O(2) degradation and superoxide quenching yeast extract ability. This study suggests that Trolox treatment provides prevention against intracellular ROS formation. Trolox application as therapeutic agent against intracellular ROS formation would be worth considering. Additionally, results indicate that yeasts are good model organisms for studying intracellular oxidation and oxidative stress. The obtained results on yeast cells might be useful to direct further human-related search for the Trolox evaluation as a human supplement used for protecting cells against intracellular free radical formation.