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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:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Justification for type of information:
Data is from publication.

Data source

Reference
Reference Type:
publication
Title:
A Compilation of Two Decades of Mutagenicity Test Results with the Ames Salmonella typhimurium and L5178Y Mouse Lymphoma Cell Mutation Assays.
Author:
H. E. Seifried
Year:
2006
Bibliographic source:
Chem. Res. Toxicol.

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: as mentioned below
Principles of method if other than guideline:
Bacterial gene mutation assay was carried out using S. typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538.
GLP compliance:
not specified
Type of assay:
bacterial gene mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Details on test material:
- Name of test material: C.I Briliant black BN
- Molecular formula: C28H21N5O14S4.4Na
- Molecular weight: 867.6873 g/mol
- Substance type: Organic
- Physical state: Solid
- Purity: No data available
- Impurities (identity and concentrations): No data available

Method

Target gene:
Plate incorporation method
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA98, TA100, TA1535, TA1537, and TA1538.
Details on mammalian cell type (if applicable):
No data available
Additional strain / cell type characteristics:
other: Salmonella typhimurium is a histidine auxotroph strain.
Metabolic activation:
with and without
Test concentrations with justification for top dose:
Test concentration:
Dose (µg /plate): conc. in the range of 10-10000 µg /plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Appropriate solvent was used for preparing the stock solution of the test chemical. Name of the solvent is not specified in the study.
Controls
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
not specified
True negative controls:
yes
Positive controls:
yes
Positive control substance:
not specified
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation
DURATION
- Preincubation period: 48-h
- Exposure duration: 37 ± 2ᵒC
- Expression time (cells in growth medium): 48 hr
- Selection time (if incubation with a selection agent): No data available
- Fixation time (start of exposure up to fixation or harvest of cells): No data available
SELECTION AGENT (mutation assays): No data available
SPINDLE INHIBITOR (cytogenetic assays): No data available
STAIN (for cytogenetic assays): No data available
NUMBER OF REPLICATIONS: Triplicates
NUMBER OF CELLS EVALUATED: 1-2 × 109 cells/ml
DETERMINATION OF CYTOTOXICITY
- Method: No data available
- Other: Cytotoxicity was observed in a preliminary dose range-finding study using strain TA100.
OTHER EXAMINATIONS:
- Determination of polyploidy: No data available
- Determination of endoreplication: No data available
- Other: : No data available
OTHER: The test materials were stored at -20ᵒC, 4ᵒC, or room temperature as required to maintain compound stability. The test chemical was analyzed for purity by Midwest Research Institute (MRI).

Five doses of test chemical, together with the appropriate concurrent solvent and positive controls, were tested on each tester strain without metabolic activation and also with activation by induced rat and hamster liver S9 preparations.

The test bacterial cultures were grown overnight in Oxoid nutrient broth no. 2 and were removed from incubation when they reached a density of (1-2) × 109 cells/ml.

On the day of use, all tester strain cultures were checked for genetic integrity.
Evaluation criteria:
The result was considered positive if at least a doubling in the mean number of revertants/plate of at least one tester strain was found.
Statistics:
No data available

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA98, TA100, TA1535, TA1537, and TA1538.
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
Positive controls validity:
not specified
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No data available
- Effects of osmolality: No data available
- Evaporation from medium: No data available
- Water solubility: No data available
- Precipitation: No data available
- Other confounding effects: No data available

RANGE-FINDING/SCREENING STUDIES: Preliminary dose range-finding study was performed using Salmonella typhimurium strain TA100.

COMPARISON WITH HISTORICAL CONTROL DATA: No data available

ADDITIONAL INFORMATION ON CYTOTOXICITY: No data available
Remarks on result:
other: No mutagenic effect were observed

Applicant's summary and conclusion

Conclusions:
The test substance was considered to be non-mutagenic in the test bacterial strain TA98, TA100, TA1535, TA1537, and TA1538. (with and without metabolic activation system).
Executive summary:

The mutagenic potency of test chemical was tested by the plate incorporation method usingSalmonella typhimuriumstrainTA98, TA100, TA1535, TA1537, and TA1538. When the test bacterial strain is exposed with the test chemical for 48hrs, no mutagenic response was seen in any of the strains of Salmonella typhimurium(with and without metabolic activation system).Therefore the test substance was considered to be not classified for gene mutation.