Registration Dossier

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1980
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:
1980
Report Date:
1980

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to
Guideline:
other: Industrial Safety and Health Department, Labor Standard Bureau, Ministry of Labor, Japan
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Specific details on test material used for the study:
Purity: 75 wt%
Name cited in study report: NNN’N’-tetraglycidyl metaxylenediamine or PGA-X
Description at room temperatur: liquid

Method

Target gene:
- S. typhimurium: Histidine gene
- Escherichia coli: Tryptophan gene
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:
Polychlorinated biphenyl (PCB, KC-500) induced S.D. rat S9
Test concentrations with justification for top dose:
10, 50, 100, 500, 1000 and 5000 µg/ plate. 5000 µg is the recommended maximum test concentration according to the OECD guideline.
Vehicle / solvent:
DMSO
Justification for choice of solvent: The substance is readily soluble in DMSO
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
N-ethyl-N-nitro-N-nitrosoguanidine
other: 2-Aminoanthracene
Details on test system and experimental conditions:
METHOD OF APPLICATION:
preincubation

DURATION
- Preincubation period: 20 minutes at 37°C
- Exposure duration: 48 hours at 37 °C

NUMBER OF REPLICATIONS:
duplicates

DETERMINATION OF CYTOTOXICITY
Not specified
Evaluation criteria:
Test results were judged to be positive (+) if mutant colony counts were at least twice as high as natural mutant colony counts. Test results were judged to be negative (-) if mutant colony counts were lower.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium, other: TA 98, TA 1537 and TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
Top dose, only in absence of S9
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with
Genotoxicity:
positive
Remarks:
5000 µg/ plate
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with
Genotoxicity:
positive
Remarks:
at 1000 and 5000 µg/plate
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Key result
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with
Genotoxicity:
positive
Remarks:
1000 to 5000 µg/plate
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
S. typhimurium, other: TA 100 and 1535
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
ADDITIONAL INFORMATION ON CYTOTOXICITY:
In absence of S9 inhibition of bacterial growth is observed at the top dose for all tester strains
Remarks on result:
other: mutagenic potential was fairly weak compared to that of existing mutagens.

Applicant's summary and conclusion

Conclusions:
The substance shows weak mutagenic potential in the Salmonella Typhimurium TA 100, TA 1535 and Escherichia Coli WP2 uvra in presence of metabolic activation.
Executive summary:

The mutagenic activity of the test substance was evaluated in a study similar to OECD TG 471. A pre-incubation assay was performed in the tester strains S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100 and E. coli WP2 uvr A both in absence and presence of Polychlorinated biphenyl (PCB), induced rat S9 as metabolic system. The substance was tested at concentrations ranging from 10 to 5000 µg/ plate (the maximum recommended dose level). Cytotoxicity was only observed at the top-dose in absence of S9, details on the method for cytotoxicity determination are not reported. Concurrent solvent and negative controls were included and gave appropriate responses. An increase in mutant frequencies was only observed at concentrations between 1000 to 5000 µg/plate in the strains TA 100 and TA 1535 and E. coli WP2 uvr A in presence of metabolic activation. The mutagenic potential was however fairly weak compared to that of existing mutagens. Although a weak positive response in the Salmonella typhimurium and Escherichia coli reverse mutation assays was obtained, insufficient data is available to concluded if the test substance is an actual mutagen.