State Institution «Kundiiev Institute of Occupational Health of the National Academy of Medical Sciences of Ukraine», Kyiv, Ukraine
Introduction. Traditional toxicological assessments are typically conducted on animals. However, due to ethical and economic considerations, alternative in vitro methods are increasingly being explored and adopted. Among these, human and animal cell cultures are widely used. Testing on specific cell lines provides informative data on the potential effects of chemical agents, particularly reflecting their organ-specific toxicity.
The aim of the research – to assess the features and mechanisms of cytotoxicity of heavy metal compounds using in vitro cell culture.
Materials and methods of the research. The cytotoxicity of heavy metal compounds – mercury chloride, cadmium sulfate, manganese sulfate, and lead acetate – was evaluated using human cell lines: A-549 (lung adenocarcinoma), Hep-G2 (hepatocarcinoma), and HaCaT (normal keratinocytes), obtained from the Cell Bank of the R. E. Kavetsky Institute of Experimental Pathology, Oncology and Radiology of the National Academy of Sciences of Ukraine. Cytotoxicity was assessed using standard assays: the MTT (methylthiazolyldiphenyl-tetrazolium bromide) test and the SRB (sulforhodamine B) assay. Based on the results, the median lethal concentration (LC₅₀) for each compound was determined using probit analysis.
Results. Hep-G2 liver cells and A-549 lung cells were found to be the most sensitive to the toxic effects of the metal salts, while skin cells (HaCaT) showed the greatest resistance. Mercuric chloride exhibited the highest toxicity toward A-549 cells, while cadmium sulfate had the strongest effect on Hep-G2 cells. Lead acetate and manganese sulfate had the least impact on cell viability. The cytotoxicity of the tested compounds followed the order: Hg > Cd > Mn > Pb, and demonstrated clear dose–response and structure–activity relationships.
Conclusion. In vitro cell culture assays enable the prediction of general cytotoxicity and allow for LC₅₀ determination, an important indicator of acute toxicity potential. These methods facilitate quantitative evaluation and analysis of dose–response and structure–activity relationships. The concentration of a test compound delivered to individual cells can be measured and controlled with high precision, improving the accuracy of toxic concentration assessments. Cell culture models can also help estimate appropriate starting doses for in vivo studies, contributing to a reduction in the use of animals in toxicological research.
Key words: heavy metals, acute toxicity, alternative methods, cell culture
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