Comparison of basal cytotoxicity data between mammalian and fish cell lines: A literature survey

During the last 20 years, in vitro assays with fish cells have been used in ecotoxicology for testing chemicals, effluents and in toxicity identification evaluations (TIE) studies. Due to the good correlation found between the in vitro data and the in vivo fish data in ranking chemical toxicity, they have been proposed as an alternative to acute fish bioassays for toxicity screening of chemicals. Nevertheless, they are recognized to be less sensitive when compared with in vivo fish bioassays. Fish cells have slower cell cycles than mammalian cells, so it was suggested that mammalian cells could be more sensitive than fish cells for testing chemicals. However, as fish cells offer some advantages over mammalian cells, mainly related to their ease of handling, some authors found them preferable to use for routine testing. The present study was undertaken to analyze whether mammalian cell lines are more, less, or equally sensitive, compared to fish cells lines. To this end, basal cytotoxicity data from a literature survey of mammalian and fish cell lines have been compared. There was a good linear correlation of IC50 values (r = 0.915) between fish and mammalian cells for a set of 51 chemicals after 24-h of treatment. The correlation coefficient of IC50 values (r = 0.888) decreased when 24-h treated mammalian cells were correlated against 48-h treated fish cell lines. For the dataset selected for this study, fish and mammalian cells showed a similar sensitivity for most of the chemicals after being treated for 24 h. We conclude that fish and mammalian cells can equally well predict the basal toxicity of the set of chemicals used in this study, and that increased exposure periods did not increase the correlation between midpoint toxicities nor sensitivities for any of the cell lines used. The more practical handling of fish cells favors their recommendation as a better alternative for replacing fish bioassay than mammalian cells.