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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:
2011-10-19 to 2011-12-29
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.5375 - In vitro Mammalian Chromosome Aberration Test
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.10 (Mutagenicity - In Vitro Mammalian Chromosome Aberration Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Remarks:
Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, München, Germany
Type of assay:
in vitro mammalian chromosome aberration test

Test material

Constituent 1
Chemical structure
Reference substance name:
Triethoxy(3-thiocyanatopropyl)silane
EC Number:
252-161-3
EC Name:
Triethoxy(3-thiocyanatopropyl)silane
Cas Number:
34708-08-2
Molecular formula:
C10H21NO3SSi
IUPAC Name:
[3-(cyanosulfanyl)propyl]triethoxysilane

Method

Species / strain
Species / strain / cell type:
Chinese hamster lung fibroblasts (V79)
Details on mammalian cell type (if applicable):
- Type and identity of media: MEM
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
Metabolic activation:
with and without
Metabolic activation system:
Phenobarbital and ß-naphthoflavone-induced rat liver S9 mix containing 8 mM MgCl2; 22 mM KCl 5 mM Glucose-6-phosphate and 4 mM NADP
Test concentrations with justification for top dose:
Pre-experiment:
with and without metabolic activation:
0.020, 0.039, 0.078, 0.16, 0.31, 0.63, 1.25, 2.50, 5.0 and 10.0 mM

Main Experiment :
without metabolic activation:
0.40, 0.60 and 0.80 mM

with metabolic activation:
0.15, 0.30 and 0.50 mM
Vehicle / solvent:
- Vehicle (s)/solvent(s) used: DMSO (final concentration of 1% solvent v/v)
- Justification for choice of solvent/vehicle: The test item could be dissolved in DMSO and was compatible with the survival of the cells.
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
900 µg/mL
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
ethylmethanesulphonate
Remarks:
without metabolic activation
Untreated negative controls:
yes
Remarks:
0.83 µg/mL
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
cyclophosphamide
Remarks:
with metabolic activation
Details on test system and experimental conditions:
TREATMENT TIME:
4 hours (Main Experiment with and without metabolic activation)

FIXATION INTERVAL: 20 hours (Main Experiment with and without metabolic activation)
NUMBER OF REPLICATIONS: 1 experiment
NUMBER OF CELLS SEEDED: 1 x 10^4 - 5 x 10^4 cells
NUMBER OF CULTURES: two cultures per concentration
NUMBER OF CELLS SCORED: 200 cells per concentration (100 cells per culture)
DETERMINATION OF CYTOTOXICITY: Mitotic index, cell density
Evaluation criteria:
There are several criteria for determining a positive result:
- a clear and dose-related increase in the number of cells with aberrations,
- a biologically relevant response for at least one of the dose groups, which is higher than the laboratory negative control range (0.0% - 4.0% aberrant cells (with and without metabolic activation)).


Statistics:
According to OECD guidelines, the biological relevance of the results is the criterion for the interpretation of results, a statistical evaluation of the results is not regarded as necessary.

Results and discussion

Test results
Key result
Species / strain:
Chinese hamster lung fibroblasts (V79)
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
0.6 mM (without metabolic activation)
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

Results of chromosome analysis                         without metabolic activation                          
     Cytotoxicity Chromatid aberrations         Isochromatid aberrations       rel. Mitotic index (%) rel. Cell density (%)  Poly-ploidy mean % aberrant cells
Scored cells  gaps breaks  inter-changes  other  gaps breaks  inter-changes  other incl. Gaps excl. Gaps
Main Experiment 
negative control 200 - 2 3 0 0 0 0 0 0 87 100 1 2.5 1.5
solvent control 200 - 2 0 0 0 0 0 0 0 100 100 1 1.0 0.0
0.02 mM - no n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 101 n.d. n.d. n.d. n.d.
0.03 mM - no n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 95 n.d. n.d. n.d. n.d.
0.06 mM - no n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 97 n.d. n.d. n.d. n.d.
0.08 mM - no n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 85 n.d. n.d. n.d. n.d.
0.10 mM - no n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 91 n.d. n.d. n.d. n.d.
0.20 mM - no n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 80 n.d. n.d. n.d. n.d.
0.40 mM 200 no 5 12 4 2 1 0 0 0 73 89 2 10.0 7.5
0.60 mM 200 yes 7 22 1 1 1 0 0 1 48 77 1 11.5 8.5
0.80 mM 200 yes 6 28 4 1 0 1 0 0 32 48 0 13.5 12.0
EMS 900 µg/mL 200 - 7 6 8 3 1 0 6 0 105 84 1 12.5 9.5
Results of chromosome analysis
with metabolic activation
     Cytotoxicity Chromatid aberrations         Isochromatid aberrations       rel. Mitotic index (%) rel. Cell density (%)  Poly-ploidy mean % aberrant cells
Scored cells  gaps breaks  inter-changes  other  gaps breaks  inter-changes  other incl. Gaps excl. Gaps
Main Experiment 
negative control 200 - 3 3 2 0 0 0 1 0 101 101 1 4.5 3.0
solvent control 200 - 6 4 0 0 1 0 0 0 100 100 1 5.0 2.0
0.02 mM - no n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 98 n.d. n.d. n.d. n.d.
0.05 mM - no n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 96 n.d. n.d. n.d. n.d.
0.08 mM - no n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 89 n.d. n.d. n.d. n.d.
0.15 mM 200 no 8 10 0 0 0 0 0 2 86 95 0 8.5 6.0
0.30 mM 200 no 3 15 3 1 0 1 0 2 87 94 2 10.0 9.0
0.50 mM 200 no 4 31 6 1 0 0 0 1 83 82 0 15.0 14.5
0.75 mM - yes n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 63 n.d. n.d. n.d. n.d.
1.00 mM - yes n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 45 n.d. n.d. n.d. n.d.
1.25 mM - yes n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 12 n.d. n.d. n.d. n.d.
1.50 mM - yes n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 28 n.d. n.d. n.d. n.d.
CPA 0.83 µg/mL 200 - 7 13 6 0 0 1 0 1 106 99 2 11.0 9.5

n.d. not determined

Applicant's summary and conclusion

Conclusions:
Triethoxy(3-thiocyanatopropyl)silane has been tested in an in vitro chromosomal aberration test conducted according to OECD 473 and in compliance with GLP (reliability score 1). A dose-related increase in the number of aberrations was observed at all concentrations tested with and without metabolic activation. Appropriate solvent and positive controls were included and gave expected results. It is concluded that the test substance is clastogenic to mammalian cells (causes structural aberrations in chromosomes) under the conditions of the test. No evidence of polyploidy was observed.