Inhibition of the mutagenicity of 2-nitrofluorene, 3-nitrofluoranthene and 1-nitropyrene by vitamins, porphyrins and related compounds, and vegetable and fruit juices and solvent extracts.

When 21 vitamins including related compounds haemin, chlorophyllin, chlorophyll, biliverdin and bilirubin, as well as juices from five fruits and 25 vegetables and solvent extracts from the residues of fruits and vegetables were tested for their antimutagenic potencies with respect to mutagenicity induced by 2-nitrofluorene (2-NF), 3-nitrofluoranthene (3-NFA) and 1-nitropyrene(1-NP) in Salmonella typhimurium TA98 the following results were obtained. The tetracyclic nitroarenes 3-NFA and 1-NP were in general more effectively antagonized by potent antimutagenic compounds than the tricyclic 2-NF. beta-Carotene, retinol, retinal, retinoic acid, retinol palmitate, riboflavin 5'-phosphate, alpha-tocopherol, vitamins B12, C, K1 and K3 as well as biliverdin, bilirubin, chlorophyll, chlorophyllin and haemin exerted antimutagenicity against the nitroarenes cited previously. All other vitamins were inactive. While part of the juices were inactive, juices from cauliflower, carrots, chives, radishes and spinach exerted weak antimutagenic activities. However, weak to moderate co-mutagenic effects were seen with grapes, kiwi, pineapple, eggplant, celeriac, chicory greens, fennel leaves and radishes and strong effects with peppers which were not caused by the presence of growth-promoting factors. Most solvent fractions were inactive but fractions containing chlorophyll exerted antimutagenicity.