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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:
experimental study
Adequacy of study:
key study
Study period:
2004
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report Date:
2004

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
GLP compliance:
yes
Type of assay:
other: in vitro mammalian cytogenicity (B10)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

Method

Species / strain
Species / strain / cell type:
other: V79-cells of the Chinese hamster
Metabolic activation:
not specified
Metabolic activation system:
S9 liver fractions of rats, induced with phenobarbital/ß-naphthoflavone.
Test concentrations with justification for top dose:
Concentration range in the main test (with metabolic activation): 427.5 ... 1710 µg/ml
Concentration range in the main test (without metabolic activation): 427.5 ... 1710 µg/ml
Vehicle / solvent:
Minimal Essential Medium (MEM)
Details on test system and experimental conditions:
Exposure period (with metabolic activation): 4 hours
Exposure period (without metabolic activation): 28 hours

Expression time:
Not applicable.

Selection time:
Not applicable.

Fixation time:
18 and 28 hours.

Results and discussion

Test resultsopen allclose all
Species / strain:
other: as specified above
Metabolic activation:
with
Genotoxicity:
not specified
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
(> 1710 µg/ml)
Species / strain:
other: as specified above
Metabolic activation:
without
Genotoxicity:
not specified
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
(> 1710 µg/ml)
Additional information on results:
Observations:
None.
Remarks on result:
other:
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

In conclusion, it can be stated that under the experimental conditions reported, the test item did
not induce structural chromosome aberrations as determined by the chromosome aberration
test in V79 cells (Chinese hamster cell line) in vitro.
Therefore, ucb 22060 is considered to be non-clastogenic in this chromosome aberration test
with and without S9 mix when tested up to the highest required test item concentration.
Executive summary:

The test item ucb 22060, dissolved in deionised water, was structural chromosome aberrations in V79 cells of the assessed for its potential to induce Chinese hamster in vitro in two independent experiments. The following study design was performed: without S9 mix with S9 mix exp. i exp. II exp. I exp. II Exposure period 4 hrs 18hra 28 hra 4 hra 4 hra Recovery 14 hra 14 hra 24 hra Preparation interval 18 hra 18 hra 28 hra 18hrs 28 hra In each experimental group two parallel cultures were set up. Per culture 100 metaphase plates were scored for structural chromosome aberrations. The highest applied concentration in the pre-test on toxicity (171 O pg/mL; approx. 10 mM) was chosen with respect to the current OECD Guideline 473. Dose selection of the cytogenetic experiments was performed considering the toxicity data. The chosen treatment concentrations are described in Table 2 (page 17). The evaluated experimental points and the results are summarised in Table 1 (page 10). No toxic effects indicated by reduced mitotic indices or reduced cell numbers were observed after treatment with the test item. In both independent experiments, neither a statistically significant nor a biologically relevant increase in the number of cells carrying structural chromosomal aberrations was observed after treatment with the test item. No increase in the frequencies of polyploid metaphrases was found after treatment with the test item as compared to the frequencies of the controls. Appropriate mutagens were used as positive controls. They induced statistically significant increases (p