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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:
1984
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1984
Report Date:
1984

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
(only four strains were tested)
GLP compliance:
no
Remarks:
(quality assurance statement was provided)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
not specified
Details on test material:
- Name of test material (as cited in study report): TK 13 076 (ORACET Gelb GHS)
- Analytical purity: Commercial grade
- Lot/batch No.: EN 63279.32
- Expiration date of the lot/batch: Ensured by sponsor
- Stability under test conditions: Ensured by sponsor
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: EN 63279.32

Method

Target gene:
Histidine gene

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9 mix
Test concentrations with justification for top dose:
20, 80, 320, 1280 and 5120 µg/0.1 mL
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Dimethylformamide (DMF)
- Justification for choice of solvent/vehicle: The test substance was soluble in DMF.
Controlsopen allclose all
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: daunorubicin-HCl
Remarks:
(for strain TA 98 without metabolic activation)
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
Remarks:
(for strain TA 100 without metabolic activation)
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: N-methyl-N'-nitro-N-nitrosoguanidine
Remarks:
(for strain TA 1535 without metabolic activation)
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: 9(5)aminoacridine hydrochloride
Remarks:
(for strain TA 1537 without metabolic activation)
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
cyclophosphamide
Remarks:
(for strain TA 1535 with metabolic activation)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

Each Petri dish contained:
1) approx. 20 mL of minimum agar (Vogel-Bonner Medium E) and glucose,
2) 0.1 mL of the solution of the test substance or the vehicle and 0.1 mL of a bacterial culture in 2.0 mL of soft agar.

The soft agar was composed of: 100 mL of 0.6 % agar solution with 0.6% NaCl and 10 mL of a solution of 1-histidine, 0.5 mM and +biotin 0.5 mM. In the experiments in which the substance was metabolically activated, 0.5 mL of an activation mixture was added also. 1 mL activation mixture contained: 0.3 mL S9 fraction of liver from rats (Tif:RAIf(SPF)) induced with Aroclor 1254 and 0.7 mL of a solution of cofactors. In the experiments without and with the addition of microsomal activation mixture three Petri dishes were prepared per strain and per group (i.e. per concentration or per control group). The plates were incubated for about 48 h at 37±1.5⁰C in darkness.
Evaluation criteria:
When the colonies had been counted, the arithmetic mean was calculated. The test substance is generally considered to be non-mutagenic if the colony count in relation to the negative control is not doubled at any concentration.
Statistics:
no data

Results and discussion

Test results
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:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
True negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
In the experiments performed without and with microsomal activation, comparison of the number of histidine-prototrophic mutants in the controls and after treatment with the test substance revealed no marked differences. At the concentrations of 320 µg/0.1 mL and above the substance precipitated in soft agar.

Applicant's summary and conclusion

Conclusions:
The test substance was not considered to be mutagenic in the Salmonella typhimurium reverse mutation assay.
Executive summary:

The test substance (of commercial grade purity) was tested for mutagenic effects on histidine auxotrophic mutants of Salmonella typhimurium in compliance/equivalent to OECD 471 with deviation, i.e. only four strains were tested. The investigations were performed on strains TA 98, TA 100, TA 1535 and TA 1537 with and without microsomal activation at 20, 80, 320, 1280 and 5120 µg/0.1 mL. In order to confirm the results, the experiments were repeated. In the experiments performed with and without microsomal activation, comparison of the number of back-mutant colonies in the controls and the cultures treated with the various concentrations of the test substance revealed no marked deviations. At 320 µg/0.1 mL and above, the substance precipitated in soft agar. Under the study conditions, the test substance was not considered to be mutagenic in the Salmonella typhimurium reverse mutation assay.