LAUSR

A number of clinical trials have shown harmful effects of high-dosage antioxidant (AO) interventions. Antioxidative stress defined as a negative impact of pharmacological AOs on cells and tissues is one of the concepts being discussed in this regard. However, the number of experimental studies on this topic is quite limited. As a rule, experimentally revealed negative impact of high AO doses on cells is associated with a variety of side-effects of each individual substance. Thereby, the basic question that arises when trying to generalize published results is as follows: is it possible to determine the acute antioxidative stress as a specific type of damaging effect arising from the abrupt lowering of the basal ROS level in cells? If yes, what are the basic features and outcomes of this stress? Here we propose our point of view, basing on the analysis of cell response to high doses of AOs of different origin and type of activity. We show that all tested AOs can block cell proliferation, hamper both initiation and progression of DNA synthesis, lead to DNA strand breaks accumulation, and disturb regulation of DNA synthesis in normal human stem and non-stem cell cultures. The outcomes of the stress depend on the cell type.