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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Data is from peer reviewed publication

Data source

Reference
Reference Type:
publication
Title:
Mutagenicity of Azo Dyes Used in Foods, Drugs and Cosmetics Before and After Reduction by Clostridium Species from the
Author:
F. RAFII, J. D. HALL and C. E. CERNIGLIA
Year:
1997
Bibliographic source:
Food and Chemical Toxicology 35 ,897-901

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other:
Principles of method if other than guideline:
To evaluate not only the mutagenicity of the D&C Red No. 33 themselves but also that of the reduction products. In the present study, we have evaluated the mutagenic activity of D&C Red No. 33 that are commonly used in foods, drugs and cosmetics, prior to and following reduction by azo reductase-producing bacteria isolated from the human gastrointestinal tract, using the Salmonella typhimurium plate incorporationAssay.
GLP compliance:
not specified
Type of assay:
bacterial gene mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
not specified
Details on test material:
- Name of test material: D&C Red No. 33- Molecular formula: C16-H13-N3-O7-S2.2Na- Molecular weight: 467.3889 g/mol- Substance type: Organic - Physical state: No data available.- Purity- No data available.- Impurities (identity and concentrations): No data available.

Method

Target gene:
No data
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 98 and TA 100
Details on mammalian cell type (if applicable):
Not applicable
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
RAT LIVER S-9, AROCLOR 1254
Test concentrations with justification for top dose:
50 or 200 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
other: 1,6-dinitropyrene
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)DURATION- Preincubation period:- Exposure duration: No data available.- Expression time (cells in growth medium): No data available.- Selection time (if incubation with a selection agent): No data available.- Fixation time (start of exposure up to fixation or harvest of cells): No data available.SELECTION AGENT (mutation assays):SPINDLE INHIBITOR (cytogenetic assays):STAIN (for cytogenetic assays):NUMBER OF REPLICATIONS: No data available.NUMBER OF CELLS EVALUATED:DETERMINATION OF CYTOTOXICITY- Method: mitotic index; cloning efficiency; relative total growth; other: No data available.OTHER EXAMINATIONS:- Determination of polyploidy:- Determination of endoreplication:- Other:OTHER: Reduction of D&C Red No. 33 dye was done by using azo reductase-producing bacteria isolated from the human gastrointestinal tract, naming Clostridium strain.Cultures of Clostridium in BHI, PRAS were incubated with either 0.5 mg or 2 mg of one of the dyes per ml at 37°C until the dyes were completely decolorized. 5 mg sodium dithionite (Sigma Chemical Co. St Louis, MO, USA) was added to each of the cultures, which were centrifuged at 3180g for 30 min. The supernatants were filtered through a 0.2µm Acrodisc filter from Gelman Science and 100/A of each culture filtrate was used directly as the source of metabolites for the mutagenicity assay. A culture of Clostridium in BHI, PRAS, grown without azo dyes but otherwise treated the same way, was used as a negative control.
Evaluation criteria:
The evaluation of mutagenicity, the numbers of revertants for S. typhimurium with 1,6-dinitropyrene, benzo[a]pyrene and the azo dyes before reduction were compared with the numbers with DMSO. The numbers of revertants for S. typhimurium with azo dye metabolites were compared with those with the culture filtrates from dye-free Clostridium cultures. There was a positive mutagenic response due to the controls (l,6-dinitropyrene and benzo[a]pyrene) compared with DMSO.
Statistics:
No data available.

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA 98,TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
No data
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

D&C Red No. 33 and its reduced metabolites in the concentration of 50 and 200 do not cause genetic mutation(s) when Salmonella typhimurium Strain-TA 98, TA 100 exposed to the test chemical in the presence and absence of metabolic activation (S9).

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):negative with and withoutD&C Red No. 33 in the concentration of 50 and 200 µg/plate did not show any evidence of gene toxicity when Salmonella typhimurium Strain-TA 98, TA 100 were exposed to the test chemicals. Hence the test chemical is not likely to be gene mutant in vitro.
Executive summary:

In a gene toxicity test, Salmonella typhimurium Strain-TA 98 and TA 100 were exposed to D&C Red No. 33 in the concentration of 50 and 200 µg/plate with and without metabolic activation. In addition D&C Red No. 33 metabolites were also prepared by treating with azo reductase -producing bacteria namely Clostridium strain isolated from the human gastrointestinal tract. The results showed that there was no evidence of gene toxicity after treatment with D&C Red No. 33 in the concentration of 50 and 200 µg/plate in Salmonella typhimurium Strain-TA 98, TA 100. Independently of tested D&C Red No. 33 reduced metabolite in the concentration of 50 and 200 µg/plate showed that there was no evidence of gene toxicity. Therefore, it is considered that D&C Red No. 33 and its reduced metabolites in the concentration of 50 and 200 µg/plate do not cause genetic mutation(s) when Salmonella typhimurium Strain-TA 98 and TA 100 are exposed to the test chemical in the presence and absence of metabolic activation (S9). Hence the test chemical is not likely to be gene mutant in vitro.