Cytotoxicity testing of 114 compounds by the determination of the protein content in Hep G2 cell cultures

The cellular protein content measured in cultured Hep G2 cells was used as the endpoint for determining the cytotoxicity of a range of 114 chemical compounds. The relative toxicity of the test compounds was quantified by the determination of the PI(50), which is the concentration of xenobiotic required to produce a 50% reduction in protein content of the culture after 24 hr. Surfactants and heavy metals consistently had low PI(50) values. Hep G2 cells were very sensitive to compounds with more than one carboxyl group. Triacetin and glutathione were identified as false positives. The results suggest that the PI(50) assay could be a useful pre-screening method to test for the cytotoxicity of chemicals.