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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2016-04-11 to 2016-05-02
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report date:
2016

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
1-acetyl-4-(4-hydroxyphenyl)piperazine
EC Number:
267-744-8
EC Name:
1-acetyl-4-(4-hydroxyphenyl)piperazine
Cas Number:
67914-60-7
Molecular formula:
C12H16N2O2
IUPAC Name:
1-[4-(4-hydroxyphenyl)piperazin-1-yl]ethan-1-one
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name of test material: JNJ-119379-AAA (T001141)
- Physical state: solid (powder)
- Appearance: white powder
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: I15FB3131
- Expiration date of the lot/batch: 2017-06-11 (retest date)
- Date of Manufacture: 2015-06-12

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature
- Stability under test conditions: not indicated
- Solubility and stability of the test substance in the solvent/vehicle: not indicated
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not indicated

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test item was dissolved in DMSO. Preparation of test solutions started with solutions of 50 mg/ml applying treatment with ultrasonic waves resulting in a clear colourless solution. The lower test concentrations were prepared by subsequent dilutions in DMSO. Test item concentrations were used within 2 hours of preparation.

Method

Target gene:
The Histidine locus in S. typhimurium strains (TA98, TA100, TA1535 and TA1537) and the Tryptophan locus in E. coli strains (WP2uvrA)
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S9-mix (Aroclor 1254 induced rat liver metabolic activation system)
Test concentrations with justification for top dose:
Dose-range finding test: 1.7, 5.4, 17, 52, 164, 512, 1600 and 5000 μg/plate with and without 5% S9-mix (TA100 and WP2uvrA) (top dose selected based
on the solubility findings)
Mutation experiment I: 52, 164, 512, 1600 and 5000 μg/plate with and without 5% S9-mix (TA98, TA1535 and TA1537) (top dose selected based on the dose ran
ge finding test results)
Mutation experiment II: 492, 878, 1568, 2800 and 5000 μg/plate with and without 10% S9-mix (all tester strains) (top dose selected based on the
dose range finding test and mutation experiment I results)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The test item was observed to be insoluble in water at 50 mg/ml (the test item sank to the bottom). The test item was soluble at 50 mg/ml (= 5000 μg/plate) in DMSO after treatment with ultrasonic waves. Based on these solubility findings, DMSO was selected as vehicle.
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
Without metabolic activation; 5 µg/plate (TA1535)
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: ICR-191
Remarks:
Without metabolic activation; 2.5 µg/plate (TA1537)
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
Without metabolic activation; 10 µg/plate (TA98)
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
methylmethanesulfonate
Remarks:
Without metabolic activation; 650 μg/plate (TA100)
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
Remarks:
Without metabolic activation; 10 μg/plate (WP2uvrA)
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
With S9-mix; 2.5μg/plate (TA1535 with 5 and 10% S9-mix, TA1537 with 5% S9-mix), 5μg/plate (TA1537 with 10% S9-mix), 1μg/plate (TA98 with 5 and 10% S9-mix, TA100 with 5% S9-mix), 2μg/plate (TA100 with 10% S9-mix), 15μg/plate (WP2uvrA with 5 and 10% S9-mix)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

Top agar in top agar tubes was melted by heating to 45 ± 2°C. The following solutions were successively added to 3 ml molten top agar:
- 0.1 ml of a fresh bacterial culture (10^9 cells/ml) of one of the tester strains,
- 0.1 ml of a dilution of the test item in DMSO and
- either 0.5 ml S9-mix (in case of activation assays) or 0.5 ml 0.1 M phosphate buffer (in case of non-activation assays).
The ingredients were mixed on a Vortex and the content of the top agar tube was poured onto a selective agar plate. After solidification of the top agar, the plates were inverted and incubated in the dark at 37.0 ± 1.0 °C for 48 ± 4 h. After this period revertant colonies were counted.

DURATION
- Exposure duration: 48 ± 4 h
- Selection time: 48h (simultaneous with exposure)

SELECTION AGENT (mutation assays): Histidine (S. Typhimurium histidine-dependent strains); Tryptophan (E. coli tryptophan-dependent strains)

NUMBER OF REPLICATIONS: all concentrations for all experiments were tested in triplicate

DETERMINATION OF CYTOTOXICITY
- Method: reduction of the bacterial background lawn; increase in the size of the microcolonies; reduction of the revertant colonies
Evaluation criteria:
A test item is considered negative (not mutagenic) in the test if:
a) The total number of revertants in the tester strain TA100 or WP2uvrA is not greater than two (2) times the concurrent vehicle control, and the total number of revertants in tester strains TA1535, TA1537 or TA98 is not greater than three (3) times the concurrent vehicle control.
b) The negative response should be reproducible in at least one follow-up experiment.

A test item is considered positive (mutagenic) in the test if:
a) The total number of revertants in tester strain TA100 or WP2uvrA is greater than two (2) times the concurrent vehicle control, or the total number of revertants in tester strain TA1535, TA1537 or TA98 is greater than three (3) times the concurrent vehicle control.
b) A concentration related effect is observed.
c) In case a follow up experiment is performed when a positive response is observed in one of the tester strains, the positive response should be reproducible in at least one follow up experiment.
Statistics:
No formal hypothesis testing was done.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium, other: TA1535, TA1537, TA98 and TA100
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
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Water solubility : The test item was observed to be insoluble in water at 50 mg/ml (the test item sank to the bottom)
- Precipitation: Precipitation of the test item on the plates was not observed at the start or at the end of the incubation period in any of the strains in both experiments

RANGE-FINDING/SCREENING STUDIES: The test item was tested in the tester strains TA100 and WP2uvrA at concentrations of 1.7, 5.4, 17, 52, 164, 512, 1600 and 5000 μg/plate in the absence and presence of 5% (v/v) S9-mix. Normal bacterial background lawn and no precipitate were observed up to the highest dose. Based on these results, the dose ranges for mutation experiment I (TA98, TA1535 and TA1537) were selected.

HISTORICAL CONTROL DATA (with ranges, means and standard deviation and confidence interval (e.g. 95%)
- Positive historical control data: The strain-specific positive control values were within the laboratory historical control data ranges
- Negative (solvent/vehicle) historical control data: The negative control values were within the laboratory historical control data ranges

ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Measurement of cytotoxicity used: Reduction in bacterial background lawn; increase in size of the microcolonies; reduction of revertant colonies
- Other observations when applicable: There was no reduction of the bacterial background lawn and no biologically relevant decrease in the number of revertants at any of the concentrations tested in all tester strains in the absence and presence of S9-mix.

Any other information on results incl. tables

Mutation experiment 1

Toxicity: In strain TA1537 (absence and presence of S9-mix), fluctuations in the number of revertant colonies below the laboratory historical control data range were observed. However, since no dose-relationship was observed, these reductions are not considered to be caused by toxicity of the test item. It is more likely that these reductions are caused by incidental fluctuations in the number of revertant colonies.

Applicant's summary and conclusion

Conclusions:
Interpretation of results:
negative without metabolic activation
negative with metabolic activation

Based on the results of this study it is concluded that the test item is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay.