ATLA::Alternatives to Laboratory Animals

Volume 29, Number 3

Cytotoxicity of the MEIC reference chemicals in antioxidant-enriched rat hepatoma-derived Fa32 cells.

ATLA 29, 217-223, May/June 2001

Paul J. Dierickx, Claudia Smit and Ellen M. Scheers

Instituut voor Volksgezondheid, Afdeling Toxikologie, Laboratorium Biochemische Toxikologie, Wytsmanstraat 14, 1050 Brussels, Belgium

SUMMARY

Since vitamin E increases the antioxidant status of cells, its influence on cytotoxicity was investigated. The neutral red uptake (NRU) inhibition effects of 39 MEIC reference chemicals were measured after treatment of rat hepatoma-derived Fa32 cells in the presence of vitamin E for 30 minutes. The results were quantified in terms of the NI50, the concentration of test compound required to reduce the NRU by 50%. Sodium chloride was the only chemical that was more toxic in the presence of vitamin E. This effect was related to the concentration of vitamin E in the cell culture medium. A vitamin E dose-related response was also observed for the decreased toxicity of paracetamol and caffeine. Glutathione levels were slightly increased in the presence of vitamin E, which could contribute to the protective effect of vitamin E. Of the remaining chemicals, 50% were less toxic in the presence of vitamin E, but the correlation with the acute human toxicity data of the MEIC study was not improved. The results imply that reactive oxygen species interfere with the toxicity of a high proportion of toxic chemicals. The assay described provides a quick and easy method for checking whether reactive oxygen species contribute to the toxicity of a chemical.

Keywords: Fa32 cells, cytotoxicity, neutral red uptake, vitamin E, antioxidant status, protection, human toxicity