Cytotoxic effects of food additives and pharmaceuticals on cells in culture as determined with the neutral red assay.

The acute cytotoxicity of butylated hydroxytoluene and butylated hydroxyanisole to cultured human dermal fibroblasts, keratinocytes, melanocytes, and melanoma tumor cells was determined with the neutral red assay. For all cell types, butylated hydroxytoluene proved to be more cytotoxic than butylated hydroxyanisole. The neutral red assay is a rapid, economical, semiautomated assay that can be used with a variety of cell types in culture to provide quantitated data that can be used to rank test agents according to their potencies.