Effects of Short-Chain Chlorinated Paraffins Exposure on the Viability and Metabolism of Human Hepatoma HepG2 Cells

Short-chain chlorinated paraffins (SCCPs) have attracted considerable attention for their characteristic of persistent organic pollutants. However, very limited information is available for their toxic effects at environmentally relevant doses, limiting the evaluation of their health risks. In this study, cell viability assay and targeted metabolomic approach was used to evaluate the environmental dose (<100 mu g/L) effect of SCCPs on HepG2 cells. Cell viability was found to be decreased with increases in exposure dose of SCCPs. Exposure for 48 h to C-10-CPs resulted in a significant reduction in cell viability compared with 24 h, even at 1 mu g/L. SCCPs exposure altered the intracellular redox status and caused significant metabolic disruptions. As a kind of peroxisome proliferator, SCCPs specifically stimulated the beta-oxidation of unsaturated fatty acids and long-chain fatty acids. Meanwhile, SCCPs exposure disturbed glycolysis and amino acid metabolism, and led to the up-regulation of glutamate metabolism and urea cycle. The toxic effects of SCCPs might mainly involve the perturbation of energy production, protein biosynthesis, fatty acid metabolism, and ammonia recycling.