Evaluation of Pluronic Polyol F127 as a vehicle for petroleum hydrocarbons in the Salmonella/microsomal assay.
Complex hydrocarbon mixtures have proven difficult to evaluate in in vitro mutagenicity assays owing to their insolubility in aqueous environments. Pluronic Polyol F127 (BASF Wyandotte, Parsippany, NJ), prepared as a 50% (w/w) solution in absolute ethanol, proved effective in emulsifying various petroleum hydrocarbon fractions. Its effectiveness in the Salmonella/microsomal assay was evaluated using model solutions each comprising a polycyclic aromatic hydrocarbon (PAH) dissolved in mineral oil. The PAHs used were benzo(a)pyrene, 3-methylcholanthrene, and 7,12-dimethylbenz(a)anthracene. Model solutions were evaluated neat and as emulsions with the Pluronic F127 solution or Tween 80. Similar levels of each PAH were prepared in dimethyl sulfoxide (DMSO) for comparison. Cytotoxicity and mutagenesis were evaluated in the preincubation technique using strain TA97. Little or no cytotoxicity or mutagenesis was evident for model solutions tested neat. However, emulsification of these PAH-laden mixtures with the Pluronic F127 solution yielded cytotoxic and mutagenic responses similar to, or greater than, those observed for PAHs delivered in DMSO. Model mixtures emulsified with Tween 80 were less active. Study results demonstrate that Pluronic F127, prepared as a 50% (w/w) solution in absolute ethanol, is an effective vehicle for evaluating the mutagenic potential of complex hydrocarbon mixtures containing PAHs in the Salmonella/microsomal assay. Since PAHs are a class of insoluble hydrocarbons, the results also suggest the potential usefulness of the Pluronic F127 solution to detect the mutagenicity of other insoluble hydrocarbons and hydrocarbon mixtures.
PubMed Abstracts
PubMed Abstracts