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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in mammalian cells
Remarks:
Type of genotoxicity: gene mutation
Type of information:
other: read across from similar substance
Adequacy of study:
key study
Study period:
1994
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, test procedure in accordance with OECD 476 methodes, meets generally accepted scientific principles, acceptable for assessment and GLP compliant. Justification for Read Across will be provided in section 13.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report date:
1994

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
Deviations:
no
GLP compliance:
yes
Type of assay:
mammalian cell gene mutation assay

Test material

Constituent 1
Reference substance name:
Similar substance 2
IUPAC Name:
Similar substance 2

Method

Species / strain
Species / strain / cell type:
Chinese hamster lung fibroblasts (V79)
Details on mammalian cell type (if applicable):
Chinese Hamster ceU line V79, clone 65/3, Dr. D. Wild, Freiburg, Germany
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
no data
Test concentrations with justification for top dose:
In the preliminary toxicity test with and without metabolic activation 12 concentrations of the tested substance were tested. The concentrations selected ranged from 0.24 to 500.0 µg/ml and separated by 2-fold intervals.
In the part with metabolic activation the highest concentration produced an acute growth inhibition of 62.70%. In the part without metabolic activation the substance exerted a complete growth inhibitory effect at the highest concentration of 500.0 µg/ml. The next lower concentrations of 250.0 and 125.0 µg/ml revealed an acute growth inhibitory effect of 98.46 and 72.56% respectively.

Accordingly, four concentrations were selected for the original experiment ranging from 18.52 to 500.0 µg/ml and from 4.63 to 125.0 µg/ml in the presence and absence of metabolic activation, respectively.
In the part with metabolic activation, the growth inhibition determined after treatment at the highest concentration of 500.0 µg/ml showed a mean value of 6.91%. After expression growth was inhibited by 13.51%.
In the absence of metabolic activation no significant growth inhibitory effect was seen after treatment and expression.
The highest concentration of 500.0 µg/ml tested in the original experiment with activation was determined to be the highest suitable concentration due to solubility limitations in the vehicle. Therefore the same concentration range was tested in the respective confirmatory experiment, although no severe toxiticy was reached. In the part without metabolic activation a concentration range of 9.26 to 250.0 µg/ml was selected for the confirmatory experiment in order to reach a more pronounced toxicity at the highest concentration. In the presence of metabolic activation no significant acute cytotoxicity was obtained at the highest concentration. After expression growth was inhibited by 9.54%.
In the part without activation, the mean growth inhibition at the highest concentration of 250.0 µg/ml was 27.91% in spite of the increased concentration.
Vehicle / solvent:
No data
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
not specified
Evaluation criteria:
Cytotoxicity is determined measuring the relative cloning efficiency (survival) of the cultures after the treatment period.
Mutant frequency is determined by seeding known numbers of cells in medium containing the selective agent to detect mutant cells, and in medium without selective agent to determine the cloning efficiency (viability).
After the incubation time, colonies are counted. The mutant frequency is derived from the number of mutant colonies in selective medium and the number of colonies in non-selective medium.
Statistics:
No data

Results and discussion

Test results
Species / strain:
Chinese hamster lung fibroblasts (V79)
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
Remarks on result:
other: strain/cell type: cell line V79, clone 65/3
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

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

Based on the results of the performed experiments and under the given experimental conditions, it is concluded that the tested substance and its metabolites did not show any mutagenic activity in this forward mutation system.
Executive summary:

similar substance 2 was tested for mutagenicity, in details for the evalutation of properties to induce gene mutations.

The mutagenicity studies were conducted following OECD 476, gene mutation test with Chinese Hamster cell V79.

The studies were performed in the absence and in the presence of metabolic activation. A dose range with different doses was used. The tested substance shows no mutagenic activity.