In vitro cytotoxicity studies with the fish hepatoma cell line, PLHC-1 ( Poeciliopsis lucida)

Abstract

The PLHC-1 fish hepatoma cell line ( Poeciliopsis lucida) was used in the neutral red assay to evaluate the acute cytotoxicities of direct-acting (alkylbenzenes, phthalate diesters, and pesticides) and metabolism-mediated (benzo[ a]pyrene) toxicants. The sequence of cytotoxic potencies for the alkylbenzenes and phthalate diesters appeared to be a direct function of their hydrophobicity (as described by logarithmic octanol/water partition coefficients). The organochlorine pesticides (alachlor and p,p′-methoxychlor) were more cytotoxic than the organophosphorus pesticides (EPN, diazinon, and malathion). The PLHC-1 cell line apparently maintained sufficient xenobiotic-metabolizing capacity, as the hepatoma cells were able to metabolize benzo[ a]pyrene to cytotoxic intermediates. Xenobiotic-metabolizing capacity was temperature dependent, with enzymatic activity increasing as the temperature was increased from 28 to 34 to 37°C, was inducible by Aroclor 1254 (a chemical inducer of cytochrome P450-dependent monooxygenase activity), and was reduced by EPN (an inhibitor of P450 activity).