Registration Dossier

Diss Factsheets

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

Administrative data

Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1997-09-29 - 1998-01-05
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report date:
1998

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)
Version / remarks:
(1983)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.10 (Mutagenicity - In Vitro Mammalian Chromosome Aberration Test)
Deviations:
no
Qualifier:
according to guideline
Guideline:
JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
Version / remarks:
1986
GLP compliance:
yes (incl. QA statement)
Type of assay:
in vitro mammalian chromosome aberration test

Test material

Constituent 1
Chemical structure
Reference substance name:
Dioctadecyl 3,3'-thiodipropionate
EC Number:
211-750-5
EC Name:
Dioctadecyl 3,3'-thiodipropionate
Cas Number:
693-36-7
Molecular formula:
C42H82O4S
IUPAC Name:
dioctadecyl 3,3'-thiodipropionate
Details on test material:
- Substance type: Organic
- Physical state: Solid, white
- Storage condition of test material: Room temperature

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 (Minimal Essential Medium; SEROMED; D-12247 Berlin) supplemented with 10 % fetal calf serum
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: yes
- Periodically checked for karyotype stability: yes
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S9-mix prepared from liver of phenobarbital and b-naphthoflavone induced rats
Test concentrations with justification for top dose:
3, 6, 30, and 300 µg/mL (without activation); 3, 5, 10, 20, and 40 µg/mL (with activation)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: none
The test item was added to the culture medium.
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
no
True negative controls:
no
Positive controls:
yes
Positive control substance:
cyclophosphamide
ethylmethanesulphonate
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium. After 3 x 10 minutes of ultrasonic treatment, a homogenous suspension could be prepared. Using higher concentrations, small test article particles were observed, leading to an inhomogenous suspension.

DURATION
- Preincubation period: at least 48 h
- Exposure duration: First experiment: 4h with and without S9 mix; Second experiment: 4h with metabolic activation and 18h and 28 h without metabolic activation
- Expression time (cells in growth medium): Both 18 and 28 h for the first and second experiment, each with and without S9-mix.
- Fixation time (start of exposure up to fixation or harvest of cells): 18 and 28 h

SPINDLE INHIBITOR (cytogenetic assays): Colcemid (0.2 µg/mL culture medium)
STAIN (for cytogenetic assays): Giemsa

NUMBER OF REPLICATIONS: 2

DETERMINATION OF CYTOTOXICITY
- Method: Cell numbers of two cultures (10 coordinate defined fields per culture) were determined for each experimental group.

OTHER EXAMINATIONS:
- Determination of polyploidy: Yes
Evaluation criteria:
A test article is classified mutagenic if it induces reproducibly either a significant concentration-related increase in the number of structural chromosome aberrations or a significant and reproducible positive response for at least one of the test points.
A test article producing reproducibly neither a significant concentration-related increase in the number of structural chromosome aberrations nor a significant and reproducibly positive response at any one of the test points is considered non-mutagenic in this system.
Statistics:
Statistical significance was confirmed by means of the Fischer's exact test. However, both biological and statistical significance were considered together

Results and discussion

Test resultsopen allclose all
Species / strain:
Chinese hamster lung fibroblasts (V79)
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not applicable
Untreated negative controls validity:
valid
Positive controls validity:
not valid
Species / strain:
Chinese hamster lung fibroblasts (V79)
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not applicable
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: At 6 µg/mL and above

RANGE-FINDING/SCREENING STUDIES:
The applicable concentration range of the test article for the cytogenetic experiments was determined in a pre-test using the determination of cell numbers 24 h after start of treatment as indicator for cytotoxicity. The highest applied concentration in the pre-test was chosen with regard to the properties of the formulation of the test article. Test article concentrations between 1 - 300 µg/mL (without S9 mix) or 1 - 285 µg/mL (with S9 mix) were chosen for the assessment of the cytotoxic potential. In the absence of S9 mix reduced cell numbers to 55.0 % of control were observed after treatment with 300 µg/mL whereas in the presence of S9 mix no toxic effects were observed. Precipitation of the test article was observed 4 h after start of treatment at concentrations of 5 µg/mL and above in the absence of S9-mix and at 10 µg/mL and above in the presence of S9-mix.

COMPARISON WITH HISTORICAL CONTROL DATA: In the range
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

SUMMARY OF RESULTS

Aberrant cells in %
Exp Preparation Interval concentration (µg/ml) S9 Mix Polyploid cells (%) Mitotic indices in % of control incl. Gaps excl. Gaps* with exchanges
I 18 h solvent control - 2.5 100.0 3.5 2.0 1.0
18 h 1.5 - 4.0 108.1 2.5 2.0 0.0
18 h 3.0 - 4.0 105.2 1.5 0.5 0.0
18 h 6.0P - 4.0 98.4 2.5 1.0 0.0
18 h 300.0P - 2.0 120.2 4.0 3.0 0.5
II 18 h solvent control - 3.0 100.0 3.5 3.5 0.5
18 h 1.5 - 2.0 116.1 3.5 2.5 0.0
18 h 3.0 - 1.5 84.4 3.0 2.0 0.5
18 h 6.0P - 1.5 94.7 2.5 1.5 0.0
18 h 30.0P - 2.5 95.6 0.0 0.0 0.0
I 28 h solvent control - 3.0 100.0 1.5 1.0 0.0
28 h 3.0 - 2.0 128.5 3.5 1.5 0.0
28 h 30.0P - 3.5 111.5 2.0 0.5 0.0
II 28 h solvent control - 2.0 100.0 1.5 1.0 0.0
28 h 6.0P - 3.0 83.3 2.0 1.0 0.0
28 h 30.0P - 4.5 87.4 2.5 2.5 0.0
I 18 h solvent control + 3.0 100.0 4.0 2.0 0.0
18 h 3.0 + 1.5 85.9 2.0 2.0 0.0
18 h 5.0 + 2.0 67.7 3.5 1.5 0.0
18 h 10.0 + 3.0 71.8 5.0 4.0 0.5
18 h 20.0P + 4.0 73.5 2.5 1.5 0.0
II 18 h solvent control + 2.0 100.0 1.5 1.5 1.0
18 h 3.0 + 2.5 93.6 4.0 3.0 0.0
18 h 5.0 + 2.0 88.3 3.5 3.0 0.5
18 h 10.0P + 4.0 109.0 2.5 1.5 0.5
18 h 20.0P + 2.0 105.8 3.0 1.5 1.0
I 28 h solvent control + 2.0 100.0 1.5 1.0 0.0
28 h 10.0 + 2.5 143.8 1.5 0.0 0.0
28 h 20.0P + 4.5 123.3 0.0 0.0 0.0
II 28 h solvent control + 3.5 100.0 2.0 2.0 1.0
28 h 10.0P + 4.5 85.6 1.0 0.5 0.0
28 h 40.0P + 3.5 89.7 1.5 1.5 0.0

* inclusive cells carrying exchanges

P Precipitation occurred

Aberrant cells in the positive control groups: 11.0 % - 31.0 %

Applicant's summary and conclusion

Conclusions:
The test article is considered to be non-mutagenic in this chromosome aberration test.