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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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study conducted following official guidelines performed on analogue susbtance 1

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1981

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

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

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 1538
Metabolic activation:
with and without
Metabolic activation system:
S-9 mix
Test concentrations with justification for top dose:
20ug-5000 ug/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: complete solubility
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
cyclophosphamide
other: without S-9 mix:N-methyl-N'-nitro-N-nitroso-guanidine (MNNC) (in DMS0) for the strains TA 100, TA 98 and TA 1535/ 4-nitro-o-phenylenediamine (in DMSO) for the strain TA 1538/ 9-aminoacridine chloride monohydrate (in DMOS) for the strain TA1537
Remarks:
with S9-mix: aminoanthracene for the strains TA100,Ta98,TA1538,TA1537 and TA1535
Details on test system and experimental conditions:
METHOD OF APPLICATION: Test tubes containing 2 ml portions of soft agar which consists of 100 ml agar (0.6% agar + 0.6% NaCl) and 10 ml aminoacid solution (minimal aminoacid solution for the determination of mutants: 0.5 mM histidine + 0.5 mM biotin) are kept in a water bath at 450C, and the remaining components are added in the following order: 0.1 ml test solution /0.1 ml bacterial suspension/0.5 ml S-9 mix (in tests with metabolic activation) or 0.5 ml phosphate buffer (in tests without metabolic activation). After mixing, the samples are poured onto the Vogel-Bonner agar plates (minimal glucose agar plates) within approx. 30 seconds.

DURATION
After incubation for 48 hours at 370C in the dark, the bacterial colonies (his+ revertante) are counted.

Test system:
Ist Experiments
Strains: TA 1535, TA 100, TA 1537, TA 1538, TA 98
Doses: 0, 20, 100, 500, 2500 and 5000 uig/plate
Solvent: DNSO
Type of test, standard plate test with and without
test condition: S-9 Mix
Number o f plates: 4 test plates per dose or per control

2nd Experiment
Strain: TA 1538
Doses: 0, 20, 100, 500, 2500 and 5000 Šug/plate
Solvent: DIVSO
Type of test,
test condition: standard plate test with S-9 mix
Number of plates: 4 test plates per dose or per control

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with
Genotoxicity:
positive
Remarks:
Weakly positive reaction only with S-9 mix at 2500 >ig - 5000 ,ug/plate (factor 2.5)
Cytotoxicity / choice of top concentrations:
not specified
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with
Genotoxicity:
positive
Remarks:
from about 20ug to 100 ug
Cytotoxicity / choice of top concentrations:
not specified
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with
Genotoxicity:
positive
Remarks:
from about 500 ug/plate (TA 1537) onward with an increase in the number >of his+ >revertants by a factor of - 20 at - 500 >ug/plate
Cytotoxicity / choice of top concentrations:
not specified
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
positive
Remarks:
Without S-9 mix only slight increase in the rate at 2500 uig/plate (factor 2.0).After the addition of S-9mix mutagenicity was observed from ca. 100 ug/plate onward with an increase in the number of revertant colonies by a factor >20 at 2500-5000 ug/plate
Cytotoxicity / choice of top concentrations:
not specified
Additional information on results:
no bacteriotoxic effect was observed

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive with metabolic activation

According to the results of the present study, the test substance is mutagenic in the Ames test under the experimental conditions chosen here.
Executive summary:

The analogue substance 1 was tested for mutagenicity to bacteria with strains TA1535, TA100, TA1537, TA1538 and TA98 of Salmonella Typhimurium with and without metabolic activation. Positive reactions were detected with metabolic activation for all strains at low doses except for strain TA1535.