Retinoids as inhibitors of ortho-aminoazotoluene-induced mutagenesis in the Salmonella/liver microsome test.

Earlier, we reported that vitamin A (retinol), in vitro, exhibits a strong inhibitory effect on the mutagenicity of aflatoxin B1 in the Ames Salmonella/microsome test. This paper reports the same inhibitory effect on the mutagenicity of an aminoazo dye, ortho-aminoazotoluene. Furthermore, the inhibitory effect was exerted by retinol esters such as retinol acetate and retinol palmitate, the latter being the physiological storage form of vitamin A. The inhibition is interpreted as an effect on the mixed-function oxidases that convert ortho-aminoazotoluene to its ultimate mutagenic form.