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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:
2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study was conducted in compliance with OECD GLP (1997) and FDA GLP regulations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report Date:
2015

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: Liquid
Details on test material:
- Name of test material (as cited in study report): MTDID 9115
- Substance type: Mono-constituent
- Physical state: Liquid
- Analytical purity: 96.0%
- Purity test date: 25 February, 2015
- Lot/batch No.: 571480

Method

Target gene:
Histidine operon, tryptophan operon.
Species / strain
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Details on mammalian cell lines (if applicable):
Not applicable
Metabolic activation:
with and without
Metabolic activation system:
Arcolor induced rat liver S-9 mix
Test concentrations with justification for top dose:
15, 50, 150, 500, 1500, and 5000 ug/plate
Vehicle:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Test article solubility
Controls
Negative controls:
no
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: All strains with metabolic activation: 2-aminoanthracene, Without metabolic activation: TA98: 20nitrofluorene, TA100 and TA1535: sodium azide, TA1537: 9-aminoacridine, , Wp2 uvrA: methyl methanesulfonate
Details on test system and conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: 12 hours
- Exposure duration: 48 to 72 hours
- Expression time (cells in growth medium): 60 to 84 hours
- Selection time (if incubation with a selection agent): 60 to 84 hours
- Fixation time (start of exposure up to fixation or harvest of cells): 48 to 72 hours

SELECTION AGENT (mutation assays): Histidine or tryptophan minimal agar.

NUMBER OF CELLS EVALUATED: All colonies on all plates were counted by a Sorcerer Colony Counter or by hand where appropriate.

DETERMINATION OF CYTOTOXICITY
- Method: Background lawn condition
Evaluation criteria:
For the test article to be evaluated positive, it must cause a dose-related increase in the mean revertants per plate of at least one tester strain over a minimum of two increasing concentrations of test article as specified below:
TA1535 and TA1537: positive if the increase in mean revertants at the peak of the dose response was equal or greater than 3.0 times the mean vehicle control value.
TA98, TA100 and WP2 uvrA: Positive if the increase in mean revertants at the peak of the dose response was equal to or greater than 2.0-times the mean vehicle control value. An equivocal response is a biologically relevant increase in a revertant count that partially meets the criteria for evaluation as positive. This could be a dose-responsive increase that does not achieve the respective threshold cited above or a non-dose responsive increase that is equal to or greater than the respective threshold cited. A response was evaluated as negative if it was neither positive nor equivocal.

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
not applicable
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: None observed

RANGE-FINDING/SCREENING STUDIES: The maximum dose of 5000 ug/plate was identified in an initial mutation assay and followed up with a confimatory assay.

ADDITIONAL INFORMATION ON CYTOTOXICITY: No cytotoxicity was observed at any dose level.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Based on the results of the test, MTDID 9115 was not mutagenic in the Bacterial Reverse Mutation Assay in the presence or absence of metabolic activation.
Executive summary:

The mutagenic potential of the test article was evaluated in the Bacterial Reverse Mutation Assay with S. typhimurium strains TA98, TA100, TA1535, and TA1537 and E. coli strain WP2 uvrA in the presence and absence of a metabolic activation system (Aroclor induced - S9 mix). The study was performed in compliance with FDA GLP 21 CFR 58 and OECD GLP C(97)186/Final. The test method was based on OECD No. 471 (1997). The test article was diluted in DMSO and dosed at 15, 50, 150, 500, 1500 and 5000 ug/plate. Strain specific controls and vehicle controls were also prepared. Separate experiments were performed in the presence and absence of metabolic activation. Precipitation was noted at 500 or 1500 mg/plate. No toxicity was observed. No mutagenic responses were observed in any strain in the presence or absence of metabolic activation. Based on the results of the test, the test article was not mutagenic in the Bacterial Reverse Mutation Assay in the presence or absence of metabolic activation.