Glutathione S-transferase contribution in the Disperse Red 1 dye activation in Daphnia similis

Abstract

Approximately 65% of the dyes used for coloring fabrics in the textile industry are azo dyes. These compounds are considered recalcitrant xenobiotic because of the presence of the de azo bond N = N, and they could be hazardous to the environment through the formation of mutagenic aromatic amines. The aim of this research is to study possible metabolites of Disperse Red 1 azo dye formed by juvenile microcrustacean Daphnia similis. Based on the experiments for the determination of glutathione s-transferase(GST)in Daphnia exposed to the dye, with and without the presence of enzyme inhibitors, it will be possible to clarify whether these enzymes are involved in the activation of these compounds. Analysis of the dye concentration that remained in the culture medium will be performed by spectrophotometer analysis. The possible metabolites formed by the exposed organisms will be analyzed by Q Trap LC-MS-MS. The results will be analyzed and discussed in order to understand whether GST activation is involved in the Disperse Red 1 toxicity. Furthermore, this technique can be used in the future as a biomarker of exposure to toxic substances activated by glutathione s-transferase and it can be one more sublethal endpoint to be measured in toxicity tests.