Registration Dossier

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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study was performed according to the recommended guidelines and GLP. There were minor deviations from the protocol which did not adversely affect the study integrity.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
yes
Remarks:
Minor deviation which did not adversely affect the study integrity.
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

Method

Target gene:
Salmonella typhimurium: histidine gene
Escherichia coli: tryptophan gene
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
not specified
Species / strain / cell type:
E. coli WP2 uvr A
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9-mix induced by a combination of phenobarbital and B-naphthoflavone
Test concentrations with justification for top dose:
1 to 3330 µg/plate in the absence and presence of 5% (v/v) S9-mix
10 to 3330 µg/plate in the absence and presence of 10% (v/v) S9-mix
Vehicle / solvent:
DMSO
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
DMSO
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
5 µg/plate in saline

Migrated to IUCLID6: for TA1535 without metabolic activation
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
60 µg/plate in milli-Q water

Migrated to IUCLID6: for TA1537 without metabolic activation
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
10 µg/plate in DMSO

Migrated to IUCLID6: for TA98 without metabolic activation
Positive controls:
yes
Positive control substance:
methylmethanesulfonate
Remarks:
650 µg/plate in DMSO

Migrated to IUCLID6: for TA100 without metabolic activation
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
Remarks:
10 µg/plate in DMSO

Migrated to IUCLID6: for WP2uvrA without metabolic activation
Positive controls:
yes
Positive control substance:
other: 2 -aminoanthracene for all tester strains with metabolic activation
Evaluation criteria:
A test substance is considered negative (not mutagenic) in the test if:
a. The total number of revertants in tester strain TA100 is not greater than two times the concurrent control, and the total number of revertants in tester strains TA1535, TA1537, TA98 or WP2uvrA is not greater than three times the concurrent control.

A test substance is considered positive (mutagenic) in the test if:
a. The total number of revertants in tester strain TA100 is greater than two times the concurrent control, or the total number of revertants in tester strains TA1535, TA1537, TA98 or WP2uvrA is greater than three times the concurrent control.
b. In case a positive response will be repeated, the positive response should be reproducible in at least one independently repeated experiment.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

All bacterial strains showed negative responses over the entire dose range, i.e. no significant dose-related increase in the number of revertants in independently repeated experiments.

The negative and strain-specific positive control values were within the laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly.

There were minor deviations from the protocol which did not adversely affect the study integrity; validity criteria have been fulfilled.

Based on the results of this study it is concluded that the test substance is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay.