Identification of biotransformation products of disperse dyes with rat liver microsomes by LC-MS/MS and theoretical studies with DNA: Structure-mutagenicity relationship using Salmonella/microsome assay

Author(s)

Franco, Jefferson Honorio ^[1] ; da Silva, Bianca F. ^[1] ; Oliveira, Regina V. ^[2] ; Meireles, Gabriela ^[3] ; de Oliveira, Danielle Palma ^[3] ; de Castro, Alexandre A. ^[4] ; Ramalho, Teodorico C. ^[4] ; Zanoni, Maria V. B. ^[1]

Affiliation

^[1] State Univ Julio de Mesquita Filho UNESP, Inst Chem, Ave Prof Francisco Degni 55, BR-14800900 Araraquara, SP - Brazil

^[2] Univ Fed Sao Carlos, UFSCar, Dept Chem, Rod Washington Luiz Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Sao Paulo FCFRP USP, Sch Pharmaceut Sci Ribeirao Preto, Sao Paulo - Brazil

^[4] Univ Fed Lavras, Dept Chem, BR-37200000 Lavras - Brazil

• Document type: Journal article
• Source: Science of The Total Environment; v. 613, p. 1093-1103, FEB 1 2018.
• Web of Science Citations: 8

Abstract

Azo dyes are known as a group of substanceswith DNA damage potential that depend on the nature and number of azo groups connected to aromatic rings (benzene and naphthalene), chemical properties, e.g. solubility and reactive functional groups, which significantly affect their toxicological and ecological risks. In this paper, we used in vitro models to evaluate the metabolism of selected textile dyes: Disperse Red 73 (DR 73), Disperse Red 78 (DR 78) and Disperse Red 167 (DR 167). To evaluate the mutagenic potential of the textile dyes, the Salmonella mutagenicity assay (Ames test) with strains TA 98 and TA 100 in the presence and absence of the exogenous metabolic system (S9) was used. DR73 was considered the most mutagenic compound, inducing both replacement base pairs (TA 100) and also changing frameshift (TA 98) mutations that are reduced in the presence of the S9 mixture. Furthermore, we used rat liver microsomes in the same experimental conditions of the S9 mixture to metabolize the dyes and the resultant solutionswere analyzed using a liquid chromatography coupled to a quadrupole linear ion trap mass spectrometry (LC-MS/MS) to investigate the metabolites formed by the in vitro biotransformation. Based on this experiment, we detected and identified two biotransformation products for each textile dye substrate analyzed. Furthermore, to evaluate the interaction and reactivity of these compounds with DNA, theoretical calculations were also carried out. The results showed that the chemical reaction occurred preferentially at the azo group and the nitro group, indicating that there was a reduction in these groups by the CYP P450 enzymes presented in the rat microsomal medium. Our results clearly demonstrated that the reduction of these dyes by biological systems is a great environmental concern due to increased genotoxicity for the body of living beings, especially for humans. (C) 2017 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 14/50945-4 - INCT 2014: National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactivies
• Grantee: Maria Valnice Boldrin
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/18109-4 - Contribution of Nanostructured Materials in Electroanalysis of pharmaceuticals and dyes, in the oxidation and reduction photoeletrocatalytic process of Inorganic and Organic Pollutants and Water Disinfection.
• Grantee: Maria Valnice Boldrin
• Support Opportunities: Regular Research Grants
• FAPESP's process: 08/10449-7 - Assessment of occurrence, toxicity/genotoxicity and degradation processes of dyes in effluents and surface water
• Grantee: Maria Valnice Boldrin
• Support Opportunities: Research Projects - Thematic Grants