Protective action of antioxidants (mexidol, carnosine, N-acetyl cysteine) and the metal chelator Ca, Na2-EDTA was studied in the culture of human neuroblastoma SH-SY5Y cells after the addition of salts of heavy metals-lead, cadmium, cobalt, and molybdenum-to the culture medium. Cells were incubated with heavy metals and protectors for 24 h, and cell viability and cell death were evaluated. All the metals lowered cell viability in a concentration-related manner. Different protective agents were studied based on this model. The most pronounced capability of increasing the cell viability in conditions of heavy-metal toxicity was demonstrated by N-acetyl cysteine (the protective effect was demonstrated at the concentrations 0.5-1.0 mM and higher). Protective potential of carnosine was somewhat lower and that of mexidol was minimal. © 2016 Kulikova et al.