Kalina Wyszyńska

Genotoxicity of industrial dyes under the inductive effect of ethanol on monooxygenase system in mice

The genotoxic effects of triarylmethane (Acid Green 16, C.I.44025) and arylmonoazo (Basic Orange 28, developed by Boruta Pigment Plant, Poland, C.I. undisclosed) dyes, were evaluated in Balb/C mice. Animals were fed for 6 days nutritionally adequate Portagen liquid diet (1 kcal/ml) or isocaloric alcoholic diet containing 5% (w/v) ethanol (36% of total calories) in order to induce the cytochrome P-4502E1 monooxygenase. Dye compounds were administered intraperitoneally 30 h before the test at doses: 90 mg/kg of Acid Green 16 and 70 mg/kg of Basic Orange 28. Bone marrow micronucleus test was used for evaluation of genotoxicity of the dyes. Ethanol caused an increase of the level of cytochrome P-450 by 200% and activities of 7-ethoxycoumarin O-deethylase (ECOD) by 650%, 7-ethoxyresorufin O-deethylase (EROD) by 460% and glutathione (GSH)-S-transferase by 60% in the liver. Both dyes exerted genotoxic effect as inferred from a 3-fold increase of frequency of micronucleated polychromatic erythrocytes in bone marrow, and a further increase (2-fold) was caused by ethanol liquid diet combined with Acid Green 16 treatment. Basic Orange 28 genotoxicity remained unaffected by ethanol. It is concluded that: (1) enhancement of genotoxic effect of Acid Green 16 by ethanol is caused by induction of cytochrome P-4502E1 monooxygenases resulting in an increased bioactivation of the dye; (2) lack of enhancement of the genotoxic effect of Basic Orange 28 by ethanol probably results from the dye- and ethanol-mediated stimulation of GSH-S-transferase, bypassing the cytochrome P-4502E1 bioactivation step.

Genotoxicity of Farbasol and its component: 4-ethyltoluene

A combination of assays for gene mutations in Salmonella typhimurium TA97a, TA98, TA100 and TA102 strains with and without rat liver activation, and for micronucleus and sister chromatid exchange (SCE) in bone marrow cells of Imp:Balb/c mice was used to provide data on the mutagenic and genotoxic properties of the mixture of aromatic solvents, known under the trade name of Farbasol. In addition, 4-ethyltoluene (the main ethylmethylbenzenic component of Farbasol) was also tested for muta- and genotoxicity. The results revealed that neither Farbasol nor 4-ethyltoluene induced an increased reverse mutation in bacterial cells or the formation of micronucleated polychromatic erythrocytes in bone marrow. However, those compounds were found to be active as sister chromatid exchange (SCE) agents.