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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:
key study
Study period:
1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Batch number: sample no.1
- Purity: 90.5 %
- Before the treatment, the test substance was stored at -20°C and protected from light and was stored at +4 °C during the treatment
- The pH of the test substance specified in the test article description was between 5 and 7.

Method

Species / strain
Species / strain / cell type:
other: TA 1535, TA 1537, TA 102, TA 98 , TA 100 and TA 102
Metabolic activation:
with and without
Metabolic activation system:
S9 fraction coming from liver of male Sprague-Dawley rats induced with Aroclor 1254 (500 mg/kg) by the intraperitoneal route
Test concentrations with justification for top dose:
12.5, 25, 31.25, 50, 62.5, 100, 125, 200, 250, 500, 750 and 1000 µg/plate.
Vehicle / solvent:
DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: With S9: sodium azide, 9-amino-acridine, 2-nitrofluorene, mitomycine C / Without S9: 2-anthramine, Danthron
Details on test system and experimental conditions:
After a preliminary assay to define the concentrations to be used for the mutagenicity study, the test substance was tested on two independent assays.
Each assay was carried out both in the absence and in the presence of a metabolic activation system, the S9 mix, prepared from a liver microsomal fraction S9 of rats treated with Aroclor 1254.
The methods used were:
- the direct plate incorporation method for the 2 assays without S9 mix and for the first assay with S9 mix,
- the preincubation method (1 h, 37°C) for the second assay with S9 mix

The concentrations were:
- without S9 mix: 125, 250, 500, 750 and 1000 µg/plate for the first test, 31.25, 62.5, 125, 250 and 500 µg/plate for the first repeat test, 12.5, 25, 50, 100 and 200 µg/plate for the second test.
- with S9 mix: 125, 250, 500, 750 and 1000 µg/plate for both tests and for the TA 1537 and TA 98 strains in the third test.
The negative and solvent control results were equivalent to those usually obtained in our laboratory. The number of revertants induced by the positive controls was higher than the spontaneous one, which demonstrated the sensitivity of this test and the efficacy of the S9 mix throughout this study.

Results and discussion

Test results
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
The test substance did not induce any significant increase in the revertant number with or without S9 mix in any of the 5 strains.
Remarks on result:
other:
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Under the experimental conditions, the substance did not show mutagenic activity in the Ames test.
Executive summary:

The in vitro potential mutagenic activity of the substance was investigated by the Ames test using 5 strains of bacteria Salmonella typhimurium: TA 1535, TA 1537, TA 102, TA 98 and TA 100 (OECD 471, GLP).

After a preliminary assay to define the concentrations to be used for the mutagenicity study, the test substance was tested on two independent assays. Each assay was carried out both in the absence and in the presence of a metabolic activation system, the S9 mix, prepared from a liver microsomal fraction S9 of rats treated with Aroclor 1254. The methods used were:

- the direct plate incorporation method for the 2 assays without S9 mix and for the first assay with S9 mix,

- the preincubation method (1 h, 37'C) for the second assay with S9 mix.

The concentrations were:

-          without S9 mix:

.          125, 250, 500, 750 and 1000 gg/plate for the first test,

.          31.25, 62.5, 125, 250 and 500 µg/plate for the first repeat test,

.          12.5, 25, 50, 100 and 200 µg/plate for the second test.

-          with S9 mix:

.          125, 250, 500, 750 and 1000 µg/plate for both tests and for the TA 1537 and TA 98 strains in the third test.

The negative and solvent control results were equivalent to those usually obtained in our Laboratory. The number of revertants induced by the positive controls was higher than the spontaneous one, which demonstrated the sensitivity of this test and the efficacy of the S9 mix throughout this study.

The substance did not induce any significant increase in the revertant number with or without S9 mix in any of the 5 strains.