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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
Study period:
2005
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP Guideline study on primary toxic metabolite, acrolein.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2006
Report date:
2006

Materials and methods

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

Test material

Constituent 1
Reference substance name:
Acrolein
IUPAC Name:
Acrolein
Constituent 2
Reference substance name:
Acrylaldehyde
EC Number:
203-453-4
EC Name:
Acrylaldehyde
Cas Number:
107-02-8
IUPAC Name:
acrylaldehyde
Details on test material:
Source: Aldrich
Purity: > 90%

Method

Species / strain
Species / strain / cell type:
Chinese hamster Ovary (CHO)
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-1254 induced rat or hamster liver
Test concentrations with justification for top dose:
0, 0.1, 0.3, 1.0 microgram/mL
Vehicle / solvent:
Distilled water
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: Triethylenemelamine (0.15 ug/mL) or cyclophosphamide (15 ug/mL)
Details on test system and experimental conditions:
Cultures were handled under gold lights to prevent photolysis of bromodeoxyuridine-substitutedDNA. Each test consisted of concurrent vehicle and positive controls and of three doses of acrolein; the high dose was limited by toxicity. A single flask per dose was used.

In the test without S9, cells were incubated in McCoy's 5A medium with acrolein for 12 hours; Colcemid was added and incubation continued for 2 hours. The cells were then harvested by mitotic shake-off, fixed, and stained with Giemsa.

For the test with S9, cells were treated with acrolein and S9 for 2 hours, after which the treatment medium was removed and the cells incubated for 12 hours in fresh medium, with Colcemid present for the final 2 hours. Cells were harvested in the same manner as for the treatment without S9.

The harvest time for the test was based on the cell cycle information obtained in a SCE test. Cells were selected for scoring on the basis ofgood morphology and completeness ofkaryotype (21 ± 2 chromosomes). All slides were scored blind and those from a single test were read by the same person. One hundred first-division metaphase cells were scored at each dose level. Classes ofaberrations included simple (breaks and terminal deletions), complex (rearrangements and translocations), and other (pulverized cells, despiralized chromosomes, and cells containing 10 or more aberrations). Chromosomal aberration data are presented as percentage of cells with aberrations.
Evaluation criteria:
To arrive at a statistical call for a trial, analyses were conducted on both the dose response curve and individual dose points. For a single trial, a statistically significant (P< 0.05) difference for one dose point and a significant trend (P < 0.015) were considered weak evidence for a positive response; significant differences for two or more doses indicated the trial was positive. A positive trend test in the absence of a statistically significant increase at any one dose resulted in an equivocal call. Ultimately, the trial calls were based on a consideration of the statistical analyses as well as the biological information available to the reviewers.

Results and discussion

Test results
Species / strain:
Chinese hamster Ovary (CHO)
Metabolic activation:
with and without
Genotoxicity:
ambiguous
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1. Chromosomal aberrations in CHO cells treated with acrolein.

Compound

Concentration (ug/mL)

Total Cells Scored

Number of aberrations

Aberrations/cell

% cells with aberrations

Without S9

Distilled water

 

100

1

0.01

1

Acrolein

0.1

0.3

1.0

100

100

100

2

2

5

0.02

0.02

0.05

2

2

5*

Triethylenemelamine

0.15

100

32

0.32

27

With S9

Distilled water

 

100

0

0

0

Acrolein

0.1

0.3

1.0

100

100

100

2

3

5

0.02

0.03

0.05

2

2

3

Cyclophosphamide

15

100

47

0.47

33

* p < 0.042 for linear regression trend without S9.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
ambiguous without metabolic activation no significant difference between any treatment and controls
negative with metabolic activation

Chinese hamster ovary cells treated with up to 1.0 micrograms/mL for 14 hours did not show a clear effect on chromosomal aberrations either in presence or absence of S9. A weakly significant trend was seen in absence of S9, but no pairwise comparison of test concentrations against controls showed significant differences. The study director concluded that overall the study result was negative.