Registration Dossier

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: OECD Guideline Study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
adopted July 21, 1997
Deviations:
yes
Remarks:
2-aminoanthracene is the sole positive control to proof the efficiacy of the S9-mix
GLP compliance:
yes (incl. certificate)
Remarks:
RCC CYTOTEST CELL RESEARCH GMBH , Rossdorf, Germany
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Physical state: white, solid
- Analytical purity: 97.7%
- Lot/batch No.: 01/2001 LAB
- Stability under test conditions: 8 hours in water, saline, polyethylene glycol, and CMC
- Storage condition of test material: room temperature

Method

Target gene:
his, trp
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
Phenobarbital induced rat liver S9-mix
Test concentrations with justification for top dose:
33; 100; 333; 1000; 2500; and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The solvent was chosen because of its solubility properties and its relative non-toxicity to the bacteria.
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: see table 1
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION
- Preincubation period: 60 min
- Exposure duration: at least 48 hours

NUMBER OF REPLICATIONS: three plates

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth
Evaluation criteria:
A test item is considered positive if a dose related increase in the number of revertants exceeding the threshold of twice or thrice the colony count of the corresponding solvent control is observed at more than one concentration. Furthermore, a biologically relevant and reproducible increase exceeding the threshold at one test concentration is considered as positive.
A test item producing neither a dose related increase in the number of revertants nor a biologically relevant positive response at any one of the test points is considered nonmutagenic in this system.
A biologically relevant response is described as follows:
An increase is considered relevant if in the strains TA98, TA 100, and WP2 uvrA the number of reversions will be at least twice as high and in the strains TA 1535 and TA 1537 at least three times higher as compared to the spontaneous reversion rate.
Also, a dose-dependent and reproducible increase in the number of revertants is regarded as an indication of possibly existing mutagenic potential of the test item regardless whether the highest dose induced the above described enhancement factors or not.
Statistics:
No statistical evaluation of the data is required.

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:
no cytotoxicity
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:
no cytotoxicity
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'.

Any other information on results incl. tables

In experiment I (plate incorporation test), no toxic effects were observed with and without metabolic activation. In experiment II (pre-incubation test), a minor toxic effect was observed in the presence of metabolic activation in strain TA 98 at 5000 µg/plate. No toxic effects were observed in the remaining strains.

No precipitation of the test item occurred up to the highest investigated dose.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative