Registration Dossier

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study reported in Japanese with a summary in English, but no data available concerning the year of performance or reporting.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1979

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Purity: 99.5%

Method

Target gene:
the amino acid requirement, UV-sensitive mutant and the membrane (rfa) and ampicillin resistance factor (pKM101)
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:
E. coli WP2 uvr A
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S-9 Mix of Rat liver, induced with phenobarbital and 5,6-benzoflavone
Test concentrations with justification for top dose:
0, 156.3*, 312.5, 625, 1250, 2500, 5000 ug/plate (* only without S9)
Vehicle / solvent:
Dimethylsulphoxide (DMSO)
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
yes
Positive controls:
yes
Positive control substance:
other: -S9 Mix, AF-2 (TA100, WP2, TA98), sodium azide (TA1535) and 9-aminoacridine (TA1537) +S9 Mix, 2-aminoanthracene (all strains)
Details on test system and experimental conditions:
Using the plate method, S9 Mix was tested under conditions with or wthout additives.
Mixed in a small test tube: test substance preparation 0.1 ml, phosphate buffer 0.5 ml (S9 Mix was added in the test S9 Mix 0.5 ml), test bacterial solution and 0.1 ml 2 ml Toppuaga. After mixing, the synthetic medium plates was allowed to harden on the flow.
The plates were cultured for 48 hours at 37℃.
The number of resulting colonies were calculated. The plates were grossly examined or under a stereoscopic microscope.
Evaluation criteria:
The test for five different strains of the bacteria test of at least 1 S9 Mix without additives or additives in the test, the average number of colonies on plates containing the test substance, twice that of vehicle control increased over and if it showed a dose-dependent increase in reproducibility or the substance has mutagenic in the test system (positive) were judged to be.
Statistics:
Not specified.

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:
at 5000 ug/plate
Vehicle controls validity:
valid
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:
at 5000 ug/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

N-methylaniline proved not to be genotoxic to various bacterial strains in the reverse mutation assay up to concentrations of 5000 ug/plate, which appeared to be cytotoxic by inhibiting bacterial growth.