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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:
experimental study
Adequacy of study:
key study
Study period:
January 21 to March 06 1998
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD, GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report Date:
1998

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to
Guideline:
EPA OTS 798.5265 (The Salmonella typhimurium Bacterial Reverse Mutation Test)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid - liquid: suspension
Details on test material:
- Name of test material (as cited in study report): 4-Piperidine Diphenyl Methanol (Azacyclonol) Base
- Physical state: white grain powder
- Analytical purity: 98.3 % (w/w)
- Lot/batch No.: 86000298
- Date of expiry: September 10, 1998
- Storage condition of test material: darkness at approximately 5 °C in refrigerator, protected from light
- Soluble and stable in DMSO.

Method

Target gene:
Histidine
Species / strain
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain characteristics:
other: Strains are deficient in the structure of their lipopolysaccharide layer and in DNA excision repair system. TA 98 and TA 100 also possess a modified postreplication DNA repair system which frequently causes an increase in the rate of mutations.
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254-induced rat liver post-mitochondrial fraction (S-9)
Test concentrations with justification for top dose:
First mutation experiment:
With and without metabolic activation: 4, 20, 100, 500, 2500 and 5000 µg/plate
Second mutation experiment:
With and without metabolic activation: 0.8, 4, 20, 100, 500, 2500 and 5000 µg/plate
Vehicle:
- Vehicle(s)/solvent(s) used: DMSO
Controlsopen allclose all
Negative controls:
yes
Remarks:
Solvent
Solvent controls:
yes
Remarks:
DMSO
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
TA1535 and TA 100 without S-9
Negative controls:
yes
Remarks:
Solvent
Solvent controls:
yes
Remarks:
DMSO
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
TA1537 without S-9
Negative controls:
yes
Remarks:
Solvent
Solvent controls:
yes
Remarks:
DMSO
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
TA 98 without S-9
Negative controls:
yes
Remarks:
Solvent
Solvent controls:
yes
Remarks:
DMSO
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
TA1535, TA 1537, TA 100 and TA 98 with S-9
Details on test system and conditions:
A toxicity test using histidine-enriched agar plates and a dilution of the tester strain TA 100 (designated TA 100 D) was performed in parallel with the second mutation experiment.
Evaluation criteria:
Criteria for a valid assay:
The assay is considered valid if the following criteria are met:
- the solvent control data are within the laboratory's normal control range for the spontaneous mutant frequency.
- the positive controls induced increases in the mutation frequency which were bath statistically significant and within the laboratory's normal range.

Criteria for a positive response:
A test compound is classified as mutagenic if it has either of the following effects:
a) it produces at least a 2-fold increase in the mean number of revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control at complete bacterial background lawn.
b) it induces a dose-related increase in the mean number of revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control in at least two to three concentrations of the test compound at complete bacterial background lawn.
If the test substance does not achieve either of the above criteria, it is considered to show no evidence of mutagenic activity in this system.
The test results must be reproducible.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity:
yes
Remarks:
Strain-dependent toxicity was observed in a dose range of 2500 to 5000 µg/plate.
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity:
yes
Remarks:
Strain-dependent toxicity was observed in a dose range of 500 to 2500 µg/plate and above without metabolic activation.
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Additional information on results:
The test compound proved to be toxic to the bacterial strain TA 100 D in the presence and in the absence of metabolic activation at concentration of 2500 µg/plate.
Only in the first experiment an increased number of revertants was found in the tester strain TA 1537 in the absence of S9 -mix, but this effect was caused by the law spontaneous mutation frequency of the corresponding solvent control and therefore considered to be without biological relevance.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Azacyclonol is not mutagenic in these bacterial test systems either in the absence or in the presence of an exogenous metabolizing system.