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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail
Remarks:
Only four bacterial strains used
Cross-reference
Reason / purpose for cross-reference:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1988

Materials and methods

Principles of method if other than guideline:
Suspensions of bacterial cells are exposed to the test substance by the plate incorporation method in the presence and in the absence of an exogenous metabolic activation system. In this method, the suspensions are mixed with an overlay agar and plated immediately onto the minimal medium and incubated for two days at 37˚C, The results are interpreted by counting the revertant colonies and comparing to the number of spontaneous revertant colonies on solvent-control plates.




GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
(9Z)-N,N-bis(2-hydroxyethyl)octadec-9-enamide
EC Number:
700-972-2
Cas Number:
93-83-4
Molecular formula:
C22H43NO3
IUPAC Name:
(9Z)-N,N-bis(2-hydroxyethyl)octadec-9-enamide
Test material form:
liquid
Details on test material:
No details reported

Method

Target gene:
No data
Species / strain
Species / strain / cell type:
other: S. typhimurium TA97, TA98, TA100 and TA1535
Details on mammalian cell type (if applicable):
Not applicable
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9 mix (metabolic activation enzymes and cofactors from Aroclor 1254-induced male Sprague-Dawley rat or Syrian hamster liver)
Test concentrations with justification for top dose:
Without metabolic activation: 0, 0.1, 0.3, 1, 3.3 and 10 µg/plate
With metabolic activation: 0, 3.3, 10, 33, 100 and 200 µg/plate
Vehicle / solvent:
Ethanol
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
(solvent control)
Negative solvent / vehicle controls:
yes
Remarks:
(Ethanol)
True negative controls:
not specified
Positive controls:
yes
Remarks:
(for strains TA100 and TA1535)
Positive control substance:
sodium azide
Remarks:
absence of metabolic activation
Untreated negative controls:
yes
Remarks:
(solvent control)
Negative solvent / vehicle controls:
yes
Remarks:
(Ethanol)
True negative controls:
not specified
Positive controls:
yes
Remarks:
(for strain TA 98)
Positive control substance:
other: 4-nitro-o-phenylenediamine
Remarks:
absence of metabolic activation
Untreated negative controls:
yes
Remarks:
(solvent control)
Negative solvent / vehicle controls:
yes
Remarks:
(Ethanol)
True negative controls:
not specified
Positive controls:
yes
Remarks:
(for strain TA 97)
Positive control substance:
9-aminoacridine
Remarks:
absence of metabolic activation
Untreated negative controls:
yes
Remarks:
(solvent control)
Negative solvent / vehicle controls:
yes
Remarks:
(Ethanol)
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene (all strains)
Remarks:
metabolic activation
Details on test system and experimental conditions:
- Test medium: Top agar supplemented with L-histidine and d-biotin
- Method of application: In agar (plate incorporation)
- Duration of incubation: 2 d at 37 °C
- Number of replicates: Three




Evaluation criteria:
- Positive response: Reproducible, dose-related increase in histidine-independent (revertant) colonies in any one strain/activation combination.
- Equivocal response: An increase in revertants that are not dose related, is not reproducible, or is not of sufficient magnitude to support a determination of m utagenicity.
- Negative response: When no increase in revertant colonies is observed following chemical treatment.
- There is no minimum percentage or fold increase required for a chemical to be judged positive or weakly positive.

Statistics:
Not reported

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium, other: S. typhimurium TA97, TA98, TA100 and TA1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
(at ≥3.3 µg/plate without metabolic activation; at 200 µg/plate with metabolic activation) .
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
None

Applicant's summary and conclusion

Conclusions:
Under the conditions of the study, the test substance was not mutagenic in Salmonella typhimurium strain TA97, TA98, TA100 or TA1535, with or without S9 metabolic activation.
Executive summary:

A study was conducted to determine the mutagenic potential of the test substance in a bacterial mutation assay, in compliance with GLP. Salmonella typhimurium strains TA97, TA98, TA100 and TA1535 were treated with the test substance using the Ames plate incorporation method at up to five concentration levels for each bacterial strain, in triplicate, both with and without metabolic activation (S9 mix; Aroclor induced rat and hamster liver homogenate metabolising system). The concentration range was 0.1 to 10 µg/plate (-S9 -mix) and 3.3 to 200 µg/plate (+S9 -mix). Cytotoxicity was observed at ≥3.3 µg/plate without metabolic activation and at 200 µg/plate with metabolic activation. No significant increase in the frequency of revertant colonies was recorded for any of the bacterial strains with any concentration tested, either with or without metabolic activation. The vehicle (ethanol) control or the negative control plates produced counts of revertant colonies within the normal range. All the positive control chemicals used in the test produced marked increases in the frequency of revertant colonies, both with and without the S9 -mix. Under the conditions of the study, the test substance was not mutagenic in Salmonella typhimurium strain TA97, TA98, TA100 or TA1535, with or without S9 metabolic activation (Irwin, 1999).