Carcinogenesis vol.9 no.8 pp.1513 —1515, 1988 SHORT COMMUNICATION Modifying role of vitamins on the mutagenic action of A'-methyl-A^'-nitro-A'-nitrosoguanidine

'To whom reprint requests should be sent Several vitamin compounds have been tested for their ability to suppress the mutagenicity of N-methyl-W-nitro-N-nitroso-guanidine, a direct acting mutagen/carcinogen, in Salmonella typhimurium strain TA100. Menadione, a-tocopherol, retinal and retinol have displayed high inhibitory activity. The antimutagenic activity of menadione, in particular, has been found to be remarkable in as much as less than equimolar amount can reduce the mutagenic potency of the carcinogen by 50%. In vitro data suggest that its action is mediated by accelerating the deactivation of the A'-nitroso carcinogen, possibly involving the formation of a quinone radical. Several vitamins have been found to modify mutagenic activity of carcinogens when tested in a bacterial system using Salmonella typhimurium strains. These include ascorbic acid (1 —8), retino