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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:
12 Dec 2006 - 19 Jan 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study conducted in accordance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
only one positive control used for tests with metabolic activation
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent

Method

Target gene:
histidine locus of S. typhimurium
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
other: uvrB-deletion, rfa-mutation
Species / strain / cell type:
S. typhimurium TA 102
Additional strain / cell type characteristics:
other: uvrB-deletion
Metabolic activation:
with and without
Metabolic activation system:
S9-Mix from the liver of phenobarbitone/ beta-naphthoflavone induced rats
Test concentrations with justification for top dose:
Initial test: 0, 50, 158, 500, 1581 and 5000 µg/plate
Final test: 0, 1, 2, 4, 8, 16, 32, 64, 128 µg/plate
Vehicle / solvent:
Ethylene glycol dimethylether (EGDE)
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: Sodium azide (-S9, TA 1535); Nitrofurantein (-S9, TA 100); 4-Nitro-1 ,2-phenylene diamine (-S9, TA 1537 and TA 98); Mitomycin C (-S9, TA 102); Cumene hydroperoxide (-S9, TA 102); 2-Aminoanthracene (+/-S9, all strains).
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION
- Preincubation period: 20 minutes
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 3 plates per strain and dose

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency; relative total growth
Evaluation criteria:
A reproducible and dose-related increase in mutant counts of at least one strain is considered to be a positive result. For TA 1535, TA 100 and TA 98 this increase should be about twice that of negative controls, whereas for TA 1537, at least a threefold increase should be reached. For TA 102 an increase of about 100 mutants should be reached. Otherwise, the result is evaluated as negative.

Results and discussion

Test results
Species / strain:
other: TA 1535, TA 100, TA 1537, TA 98, TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
at concentrations > 8 µg/plate (strain-specific)
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
None of the five strains used showed a dose-related and/or biologically relevant increase in mutant counts over those of the negative controls in the plate incorporation test. This applied both to the tests with and without S9 mix and was confirmed by the results of the preincubation trials.
The positive controls increased mutant counts to well over those of the negative controls.

CYTOTOXICITY:
There was no indication of a bacteriotoxic effect of the test substance at doses of up to and including 8 µg/plate. Higher doses had a strong, strain-specific bacteriotoxic effect. Therefore they could only partly be used for assessment purposes up to and including 128 µg/plate.
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