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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From May 9, 1980 to Sep. 15, 1980
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1980
Report Date:
1980

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
2-aminoanthracene was the only compound used to test the efficacy of the S9 fraction; missing some positive controls, no repeat study
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
Histidine (his- to his+) and tryptophan (tryp- to tryp+) genes in Salmonella typhimurium and Escherichia coli respectively
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 applicable
Species / strain / cell type:
S. typhimurium TA 1538
Additional strain / cell type characteristics:
not applicable
Species / strain / cell type:
E. coli WP2 uvr A
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat liver S9
Test concentrations with justification for top dose:
Concentration range (-S9 mix): 5, 10, 50, 100, 500, 1000 and 5000 µg/0.1 ml
Concentration range (+S9 mix): 5, 10, 50, 100, 500, 1000 and 5000 µg/0.1 ml
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Dimethylsulfoxide (DMSO)
Controls
Untreated negative controls:
yes
Remarks:
DMSO
Negative solvent / vehicle controls:
other: same as negative control
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: see Table 1
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)
- Amount per plate: 0.1 mL

DURATION
- Exposure duration: 48-55 hours at 37°C

NUMBER OF REPLICATIONS: 3 plates per strain per group.
-No independent repeat experiment was conducted.

TOXICITY TEST:
- In order to estimate a growth-inhibiting effect of the test substance on the bacteriam a plate test without microsomal activation was performed on Strain TA 100 with the following concentrations: 0.0001, 0.001, 0.01, 0.1, 1, 10, 50, 100, 500, 1000 and 2000 µg/0.1 mL.
Evaluation criteria:
The test substance is generally considered to be nonmutagenic if the colony count in relation to the negative control is not doubled at any concentration.
Statistics:
The arithmetic mean was calculated when the colonies had been counted. No statistical analysis test was performed.

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
Remarks:
5000 µg/0.1 ml
Vehicle controls validity:
other: same as negative control
Untreated negative controls validity:
valid
Positive controls validity:
other: valid for all strains without S9 mix and for TA 1535 with S9 mix; not examined for TA1537, TA98 and TA100 with S9 mix
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
5000 µg/0.1 ml
Vehicle controls validity:
other: same as negative control
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:
cytotoxicity
Remarks:
5000 µg/0.1 ml
Vehicle controls validity:
other: same as negative control
Untreated negative controls validity:
valid
Positive controls validity:
other: valid without S9 mix; not examined with S9 mix
Additional information on results:
At the concentration of 5000 µg/0.1 ml the substance precipitated in soft agar.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

In the experiments performed with and without microsomal activation, comparison of the number of histidine- or tryptophanprototrophic mutants in the controls and after treatment with the test item revealed no marked differences. A growth-inhibiting effect of test item

was observed with all strains at the concentration of 5000 µg/0.1 ml. At the concentration of 5000 µg/0.1 ml the substance precipitated in soft agar.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The test item is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay under the test conditions.