In vivo cytogenetic studies on male mice exposed to Ponceau 4R and beta-carotene.

Chromosomal aberrations induced by Ponceau 4R (an azo food dye) and beta-carotene (a natural food colour) were studied on bone marrow cells of mice in vivo. The results indicated that Ponceau 4R was more clastogenic than beta-carotene. Ponceau 4R was found to have a minimum effective dose of 4 mg which induced a significant number of chromosome aberrations. This dose is also the recommended 'admissible daily intake'. Chromosome aberrations induced by beta-carotene were not significantly higher than those of the control (olive oil) in the dose range 0.27 to 27 mg/kg body weight. The genotoxicity of these dyes can be attributed to their chemical composition. In so far as genotoxicity is concerned the carotenoid beta-carotene can be safely used as a food colorant whereas Ponceau 4R should be delisted as a food dye.