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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)
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Species / strain / cell type:
S. typhimurium TA 1538
Metabolic activation:
with and without
Metabolic activation system:
S9-mix from rat liver
Test concentrations with justification for top dose:
with metabolic activation: 10, 50, 100, 500, 1000 and 5000 µg/plate
without metabolic activation: 10, 50, 100, 500, 1000 and 5000 µg/plate

Vehicle / solvent:
water
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
9-aminoacridine
sodium azide
other: 2-Aminoanthracene; 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide, 4-nitro-o-phenylenediamine
Details on test system and experimental conditions:
Bacterial strains
Salmonella typhimuriurn TA100, TA98, TA1535, TA1537 and TA1538 were obtained from Professor B.N. Ames, University of California, U.S.A.
Escherichia coli WP2 uvrA was provided by Dr. T. Kada, National Institute of Genetics, Mishima, Japan.

Cultures of each strain were prepared by incubating an aliquot of parent stock culture in nutrient broth at 37°C for 18 hours.

After mixing 0.1 ml of test material solution, 0.5 ml of phosphate buffer or S-9 mix, 0.1 ml of culture of tester strain, and 2 ml of top agar in a test tube, the mixture was poured on minimal agar plate. The plates were incubated at 37°C for 2 days and scored, for revertants.

Results and discussion

Test resultsopen allclose all
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with
Genotoxicity:
ambiguous
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with
Genotoxicity:
ambiguous
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
Under the study conditions, the test substance was found to be mutagenic in most Salmonella strains in bacterial reverse mutation assay.
Executive summary:

A bacterial reverse mutation assay (Ames) was carried out, to evaluate the test substance for the mutagenic potential in a microbial assay with and without the addition of mammalian metabolic activation preparation. The test was carried out in concentrations of 10, 50, 100, 500, 1000 and 5000 µg/plate in strains of Salmonella typhimurium TA100, TA98, TA1535, TA1537 and TA1538 and Escherichia coli WP2 uvrA. Cultures of each strain were prepared by incubating an aliquot of parent stock culture in nutrient broth at 37°C for 18 hours. After mixing 0.1 ml of test material solution, 0.5 ml of phosphate buffer or S-9 mix, 0.1 ml of culture of tester strain, and 2 ml of top agar in a test tube, the mixture was poured on minimal agar plate. The plates were incubated at 37°C for 2 days and scored, for revertants.

Significant differences were observed in the number of mutant colonies between the test compound dosages and the control with Salmonella typhimurium TA100, TA98, TA1535, TA1537 and TA1538. No increases in mutation frequencies were observed in Escherichia coli WP2 uvrA.