Inhibitory effect of hemin on the mutagenic activities of carcinogens.
An inhibitory effect of hemin on mutagenicities of a range of carcinogens was found by adding hemin to the preincubation mixture of the Ames' test. Strong inhibitions were observed for benzo[alpha]pyrene, 3-methylcholanthrene, 7,10-dimethylbenz[alpha]anthracene, chrysene, 2-acetylaminofluorene, 2-nitrofluorene and aflatoxin B1. Generally, 50% inhibition was caused by an amount of hemin 1--2 equivalents to the mutagen. Excess of hemin caused complete inhibitions. Hemin did not affect the mutagenicities of 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide, 4-nitroquinoline-1-oxide, nitromin, N-methyl-N-nitrosourea, N-methyl-N'-nitro-N-nitrosoguanidine, N-nitrosodi-n-butyl-amine, quinoxaline-1,4-dioxide and carbadox. Biliverdin, bilirubin and chlorophyllin were also effective as inhibitors for the mutagenicity of benzo[alpha]pyrene.
D002273:Carcinogens / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006418:Heme / Q000031:analogs & derivatives*; D006427:Hemin / Q000494:pharmacology*; D009152:Mutagenicity Tests; D009154:Mutation / Q000187:drug effects*
D002273:Carcinogens; D006418:Heme; D006427:Hemin