Reference

Comparison of 7 azo dyes and their azo reduction products in the rat and hamster hepatocyte primary culture/DNA repair assays

Comparison of 7 azo dyes and their azo reduction products in the rat and hamster hepatocyte primary culture/DNA repair assays. Kornbrust, Douglas J.; Barfknecht, Thomas R. (Research Triangle Inst., Research Triangle Park, NC 27709-2194, USA). Mutat. Res., 136(3), 255-66 (English) 1984. CODEN: MUREAV. ISSN: 0027-5107. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) A comparison of the amt. of DNA repair induced in rat and hamster hepatocytes by 7 azo dyes and 7 arom. amine azo redn. products of the dyes was performed using the primary hepatocyte culture/DNA repair (HPC/DR) assay. Congo Red (I) [573-58-0] and its azo redn. product, benzidine [92-87-5], were more potent inducers of DNA repair in hamster than in rat hepatocytes, whereas Trypan Blue [72-57-1] and its redn. product, o-tolidine [119-93-7], were equipotent in the 2 hepatocyte systems. Evans Blue [314-13-6] elicited a greater DNA repair response in hamster hepatocytes. The abs. potency of these dyes, however, was much less than their redn. products. o-Aminoazotoluene [97-56-3] was the most potent of the dyes tested, and its DNA repair-inducing activity was much greater than that of its azo redn. products, o-toluidine and 2,5-diaminotoluene [95-70-5]. Ponceau SX [4548-53-2], which is carcinogenic in hamsters, but not in rats, was inactive in both hepatocyte systems. Dimethylaminobenzeneazo-1-naphthalene [607-59-0] and its 2-naphthalene congener [613-65-0], as well as the 1- [134-32-7] and 2-naphthylamine [91-59-8] azo redn. products of these dyes, were more potent in hamster than in rat hepatocytes. However, the DNA repair-inducing activities of the parent dyes could not be entirely accounted for by the potencies of their resp. naphthylamine derivs. Taken together, these findings extend previous observations of the superior metabolic activation capabilities of hamster, relative to rat hepatocytes, and further demonstrate the utility of testing chems. in both the hamster and rat HPC/DR assays.

Testing of 24 food, drug, cosmetic, and fabric dyes in the in vitro and the in vivo/in vitro rat hepatocyte primary culture/DNA repair assays

Testing of 24 food, drug, cosmetic, and fabric dyes in the in vitro and the in vivo/in vitro rat hepatocyte primary culture/DNA repair assays. Kornbrust, Douglas; Barfknecht, Thomas (Res. Triangle Inst., Research Triangle Park, NC 27709, USA). Environ. Mutagen., 7(1), 101-20 (English) 1985. CODEN: ENMUDM. ISSN: 0192-2521. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) Twenty-four dyes currently or previously used in the food, drug, cosmetic, and textile industries were tested in the in vitro rat hepatocyte primary culture/DNA repair (HPC/DR) assay and, to a limited extent, in the in vivo/in vitro HPC/DR assay. The pos. control, Solvent Yellow 3 (o-aminoazotoluene), and 5 other dyes (4-dimethylaminobenzeneazo-1-naphthalene [607-59-0], 4-dimethylaminobenzeneazo-2-naphthalene [613-65-0], Direct Blue 53 [314-13-6], Acid Blue 9 [2650-18-2], and 4-dimethylaminostilbene [1145-73-9]) induced DNA repair in rat hepatocytes both in vitro and in vivo, while 13 of the dyes (Food Red 1 [4548-53-2], Food Red 5 [3567-69-9], Food Orange 4 [1936-15-8], Food Red 7 [2611-82-7], Acid Red 14 [3567-69-9], Acid Red 27 [915-67-3], Pigment Red 53 [2092-56-0], Acid Yellow 23 [1934-21-0], Food Black 1 [2519-30-4], Food Green 3 [2353-45-9], Acid Red 51 [16423-68-0], Acid Blue 74 [860-22-0], and Natural Red 4 [1390-65-4]) did not produce any detectable DNA repair in either the in vitro or in vivo/in vitro assays. Direct Blue 14 (I) [72-57-1] had weak activity in vitro but none was detected in vivo. In contrast, Solvent Yellow 5 [85-84-7] was not active in vitro, but produced a weak pos. response in vivo. Neg. responses were also obtained for Solvent Yellow 14 [842-07-9] and Acid Green 5 [5141-20-8] in the in vitro assay, whereas the responses produced by these dyes in the in vivo/in vitro assay were judged to be equivocal. An equivocal response was also obtained for Direct Red 28 [573-58-0] in the in vivo/in vitro assay as well as in the in vitro assay. These findings provide information about the potential genotoxicity of a no. of dyes for which previous genotoxicity data has been inconsistent or inadequate. For some dyes (e.g., Solvent Yellow 5), discrepancies between the results obtained in the in vitro and in vivo/in vitro assays may implicate a role for intestinal microflora in their metabolic activation.