Amides, C12-18(even-numbered) and C18(unsatd.), N-hydroxyethyl

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not reported

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.17 (Mutagenicity - In Vitro Mammalian Cell Gene Mutation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

mammalian cell gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Amides, C8-18 (even numbered) and C18-unsatd., N-(hydroxyethyl)

EC Number:

931-330-1

IUPAC Name:

Amides, C8-18 (even numbered) and C18-unsatd., N-(hydroxyethyl)

Constituent 2

Reference substance name:

2,2'-iminodiethanol

EC Number:

203-868-0

EC Name:

2,2'-iminodiethanol

Cas Number:

111-42-2

Molecular formula:

C4H11NO2

IUPAC Name:

2,2’-iminodiethanol

Test material form:

solid: flakes

Method

Target gene:

Thymidine kinase

Species / strain

Species / strain / cell type:

mouse lymphoma L5178Y cells

Details on mammalian cell type (if applicable):

- Type and identity of media: Basic medium: RPMI 1640 Hepes buffered medium (Dutch modification) (Invitrogen Corporation) containing penicillin/streptomycin (50 U/mL and 50 µg/mL, respectively) , 1 mM sodium pyruvate and 2 mM L-glutamin.
Growth medium: Basic medium, supplemented with 10% (v/v) heat-inactivated horse serum (=R10 medium).
Exposure medium: For 3 h exposure cells were exposed to the test substance in basic medium supplemented with 5% (v/v) heat inactivated horse serum (R5-medium) and for 24 h exposure: Cells were exposed to the test substance in basic medium supplemented with 10% (v/v) heat inactivated horse serum (R10-medium).
Selective medium: Selective medium consisted of basic medium supplemented with 20% (v/v) heat-inactivated horse serum (total amount of serum = 20%, R20) and 5 µg/mL trifluorothymidine (TFT).
Non-selective medium: Non-selective medium consisted of basic medium supplemented with 20% (v/v) heat-inactivated horse serum (total amount of serum = 20%, R20).

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9 was prepared after inducing metabolizing enzymes by injection of rats with phenobarbitone and β-naphthoflavone.

Test concentrations with justification for top dose:

First mutagenicity test:
Without S9-mix: 0.3, 1, 3, 10, 30, 40, 50, 60, 70, 80, 90 and 100 µg/mL exposure medium
With 8% (v/v) S9-mix: 0.3, 1, 3, 10, 30, 50, 100, 150, 200, 250, 300 and 350 µg/mL exposure medium

Second mutagenicity test:
Without S9-mix: 0.3,1,3,10,15,20,22.5,25,27.5,30,32.5,35,40,45 and 50 µg/mL exposure medium
With 12% (v/v) S9-mix: 0.3, 1, 3, 10, 30, 50, 100, 125, 150, 175, 200, 225 and 250 µg/mL exposure medium

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Dimethyl sulfoxide

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

DMSO

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

Without metabolic activation Migrated to IUCLID6: 15 and 5 µg/mL for a 3 and 24 h treatment period

Controls 2

Untreated negative controls:

yes

Remarks:

DMSO

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

With metabolic activation Migrated to IUCLID6: 7.5 µg/mL

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 3h (Experiment 1), 24 and 48 h (Experiment 2 without S9 mix) and 3h (Experiment 2 with S9 mix)
- Expression time (cells in growth medium): For expression of the mutant phenotype, the remaining cells were cultured for 2 d after the treatment period. During this culture period at least 4 x 106 cells (if possible) were subcultured every day in order to maintain log phase growth. Two days after the end of the treatment with the test substance the cells were plated for determination of the cloning efficiency (CE day 2) and the mutation frequency (MF).

SELECTION AGENT (mutation assays): Trifluorothymidine 0.5 mg/mL

NUMBER OF REPLICATIONS: Two

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency

Evaluation criteria:

A test substance is considered positive (mutagenic) in the mutation assay if:
a) It induces a MF of more then MF(controls) + 126 in a dose-dependent manner; or
b) In case a repeat experiment is performed when a positive response is observed in one of the tester strains, the positive response should be reproducible in at least one independently repeated experiment.
An observed increase should be biologically relevant and will be compared with the historical control data range.
A test substance is considered equivocal (questionable) in the mutation assay if no clear conclusion for positive or negative result can be made after an additional confirmation study.
A test substance is considered negative (not mutagenic) in the mutation assay if:
a) None of the tested concentrations reaches a mutation frequency of MF(controls) + 126.
b) The results are confirmed in an independently repeated test.

Statistics:

No data

Results and discussion

Test results

Key result

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
In the absence of S9-mix, no toxicity in the relative suspension growth was observed up to concentrations of 33 µg/mL compared to the relative suspension growth of the solvent control. No cell survival was observed at test substance concentrations of 100 µg/mL and above. In the presence of S9-mix, no toxicity in the relative suspension growth was observed up to concentrations of 100 µg/mL compared to the relative suspension growth of the solvent control. Hardly any cell survival was observed at the test substance concentration of 333 µg/mL.

COMPARISON WITH HISTORICAL CONTROL DATA:
The spontaneous mutation frequencies in the solvent-treated control cultures were between the minimum and maximum value of the historical control data range and within the acceptability criteria of this assay.

Evaluation of the mutagenicity: No significant increase in the mutation frequency at the TK locus was observed after treatment with Ninol CMF-E either in the absence or in the presence of S9-mix. The numbers of small and large colonies in the test material-treated cultures were comparable to the numbers of small and large colonies of the solvent controls.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
First mutagenicity test: Evaluation of toxicity: In the absence of S9-mix, the relative total growth of the highest test substance concentration was reduced by 74% compared to the total growth of the solvent controls. In the presence of S9-mix, the relative total growth of the highest test substance concentration was reduced by 77% compared to the total growth of the solvent controls.

Second mutagenicity test: In the absence of S9-mix, the relative total growth of the highest test substance was reduced by 95% compared to the total growth of the solvent controls. In the presence of S9-mix, the relative total growth of the highest test substance concentration was reduced by 72% compared to the total growth of the solvent controls.

Any other information on results incl. tables

The growth rate over the two-day expression period for cultures treated with DMSO was between 13 and 23 (3 h treatment) and 37 and 38 (24 h treatment). Mutation frequencies in cultures treated with positive control chemicals were increased by 8.2 and 16-fold for MMS in the absence of S9-mix, and by 10- and 13-fold for CP in the presence of S9-mix, in the first and second experiment respectively. It was therefore concluded that the test conditions, both in the absence and presence of S9-mix, were appropriate for the detection of a mutagenic response and that the metabolic activation system (S9-mix) functioned properly. In addition the observed mutation frequencies of the positive control substances were within the acceptability criteria of this assay.

Applicant's summary and conclusion

Conclusions:

Under the study conditions, the test substance was not mutagenic in the TK mutation test system both with and without metabolic activation.

Executive summary:

A study was conducted to evaluate the in vitro genetic toxicity of the test substance, C8-18 and C18-unsatd. MEA (>95% active) according to OECD Guideline 476 and EU method B.17, in compliance with GLP. The test was performed in two independent experiments with L5178Y mouse lymphoma cells, in the absence and presence of S9-mix. In the first experiment, the substance was tested up to concentrations of 60 and 200 µg/mL in the absence and presence of 8% (v/v) S9-mix. The incubation time was 3 h. Test material was tested up to cytotoxic levels of 74 and 77% in the absence and presence of S9-mix, respectively. In the second experiment, test material was tested up to concentrations of 45 and 225 µg/mL in the absence and presence of 12% (v/v) S9-mix with incubation times of 24 and 3 h, respectively. The substance was tested up to the cytotoxic level of 95% (absence of S9-mix) and up to 72% (presence of S9-mix), but failed to induce a significant increase in the frequency of mutations. The spontaneous mutation frequencies in the solvent-treated control cultures were within historical control data range and therefore within the acceptability criteria of the assay. Mutation frequencies in positive control cultures were elevated 8.2- and 16-fold for MMS (absence of S9-mix), and 10- and 13-fold for CP (presence of S9-mix). Negative results were confirmed in an independent repeat experiment with extended exposures. Under the study conditions, the test substance was not mutagenic in the TK mutation test system both with and without metabolic activation (Verspeek-Rip, 2009).