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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
GLP compliance:
yes
Type of assay:
in vitro mammalian chromosome aberration test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Ethylviolet chloride, purity 83.9% main component

Method

Species / strain
Species / strain / cell type:
Chinese hamster lung fibroblasts (V79)
Metabolic activation:
with and without
Test concentrations with justification for top dose:
0.4 µg/ml, 0.6 µg/ml and 0.8 µg/ml culture medium (18 hours sampling time) and 0.8 µg/ml culture medium (28 hours sampling time) without metabolic activation or 2.0 µg/ml, 4.0 µg/ml and 6.0 µg/ml culture medium (18 hours sampling time) and 6.0 µg/ml culture medium (28 hours sampling time) in the experiment with metabolic activation were evaluated
Controls
Untreated negative controls:
yes
Remarks:
untreated
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Remarks:
Crystal violet (= Basic violet 3) at a dose level of 2.0 µg/ml (without S-9 mix) or 6.0 µg/ml (with S-9 mix). EMS and cyclophosphamide.
Details on test system and experimental conditions:
EXPERIMENTAL PERFORMANCE: Chromosomes were prepared 18 hours (low, intermediate and top dose) and 28 hours (top dose only) after test substance treatment, which lasted for about 4 hours both in the experiment with S-9 mix or without metabolic activation. Duplicate cultures were used for all experimental groups. About 2-3 hours prior to harvesting the cells, colcemid was added to arrest cells in a metaphase-like stage of mitosis (c-metaphases). After preparation of the chromosomes and staining with Giemsa, metaphases were analyzed for chromosomal aberrations.

Results and discussion

Test results
Species / strain:
Chinese hamster lung fibroblasts (V79)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
STABILITY OF THE TEST SUBSTANCE: The stability of the test substance in water over a period of 96 hours was verified analytically. With the vehicle a solution was obtained and therefore, it was not necessary to verify the homogeneity analytically.

According to the results of the present study, the test substance did not cause any significant increase in the number of structurally aberrant metaphases incl. and excl. gaps at both sampling times either without S-9 mix or after adding a metabolizing system in two experiments independent of each other. The types and frequency of aberrations were nearly in the range of that of the concurrent negative control values at both sampling times and within the range of the historical control data (range given for both sampling times with and without S-9 mix), i.e. 1.0 - 10.5% incl. gaps and 0.0 - 5.0% excl. gaps. The statistical significance obtained in the 1st experiment without S-9 mix at the lowest dose of 0.4 µg/ml is due to the low negative control value and is without any biological relevance, i.e. - there is no dose-response relationship - the figures were not confirmed in a 2nd experiment - the values are within the range of that of the historical control data. In contrast, the positive reference compound crystal violet exhibited, as expected, a very clear clastogenic activity, both with and without metabolic activation, with a high proportion of exchanges. This clastogenic activity had already been observed by scanning the slides of the pretest for quality control and was then confirmed in the 1st main experiment. Therefore, in the 2nd experiment testing of the reference substance crystal violet for further substantiation was omitted.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Under the experimental conditions chosen the test substance is considered not to be a chromosome-damaging (clastogenic) agent under in vitro conditions in V79 cells.