Cytotoxic and genotoxic effects of five n-alkanals in primary cultures of rat and human hepatocytes

Abstract Five n- alkanals were examined for cytotoxicity, as evaluated by the trypan blue exclusion test, and for genotoxicity, as evaluated by the induction of unscheduled DNA synthesis (UDS), in primary cultures of rat and human hepatocytes. After 20 h exposures, cytotoxicity was similar in cells of the two species, and increased with the length of the carbon chain. In rat hepatocytes, propanal (10–100 mM), butanal (10–100 mM), pentanal (3–30 mM) and hexanal (3–30mM) induced a modest but significant and dose-dependent increase of net nuclear grain counts, while in human hepatocytes this effect was not detected. Nonanal (3–30 mM), which showed the highest cytotoxic effect, failed to induced UDS in both cell types. These results seem to suggest that at the concentrations which are presumably attained after ingestion with food or generated by lipid peroxidation processes the five n- alkanals tested are presumably unable to induce genotoxic effects in the human liver.