Estr-4-ene-3,11,17-trione, cyclic 17-(2,2-dimethyl-1,3-propanediyl acetal) cyclic 3-(1,2-ethanediyl dithioacetal)

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Bacterial reverse mutation assay: negative; OECD 471, Donath 2012

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to guideline; under GLP conditions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

S. typhimurium TA 102

Additional strain / cell type characteristics:

not applicable

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

rat liver S9

Test concentrations with justification for top dose:

Preliminary test: 3.16, 10.0, 31.6, 100, 316, 1000, 2500 and 5000 ug/plate.
Main test: 31.6, 100, 316, 1000, 2500 and 5000 ug/plate.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: without S9: sodium azide, 4-nitro-o-phenylene-diamine or methylmethanesulfonate; with S9: 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: Experiment 1 was performed in agar (plate incorporation method); Experiment 2 was performed using the preincubation method.

DURATION
- Preincubation period: 60 minutes at 37 degrees C (for experiment 2 only).
- Expression time (cells in growth medium): Plates were incubated at 37 degrees C for at least 48 hours in the dark (for both experiment 1 and 2).

NUMBER OF REPLICATIONS: For each strain and dose level, including the controls, three plates were used. In experiment 2, there was one case where only 2 plates were evaluated.

DETERMINATION OF CYTOTOXICITY
- Method: Cytotoxicity can be detected by a clearing or rather diminution of the background lawn or a reduction in the number of revertants down to a mutation factor of approximately ≤ 0.5 in relation to the solvent control.

OTHER: To establish the dose-range, a preliminary experiment was performed using the plate incorporation method using the strains TA98 and TA100. Vehichle and eight doses (3.16, 10.0, 31.6, 100, 316, 1000, 2500 and 5000 μg/plate) of the test material were plated (in triplicate) with and without S9 mix.

Evaluation criteria:

For the test material to be evaluated as positive, it must cause a clear dose-related increase in the number of revertants and/or a biologically relevant positive response for at least one of the dose groups occurs in at least one tester strain with or without the metabolic activation. A biologically relevant increase is described as follows:

- if in tester strains TA 98, TA 100 and TA 102 the number of reversions is at least twice as high.
- if in tester strains TA 1535 and TA 1537 the number of reversions is at least three times higher than the reversion rate of the solvent control.

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. A test item producing neither a dose related increase in the number of revertants nor a reproducible biologically relevant positive response at any of the dose groups is considered to be non-mutagenic in this system.

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

A reduction in the number of revertants was observed in the TA100 strain at 1000 ug/plate without S9, but was not considered as biologically relevant due to a lack of a dose-response relationship.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Observed at 5000 ug/plate without S9 activation.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results (migrated information):
negative

Under the conditions of this study the test material did not induce gene mutations in the strains tested. The test material can therefore considered as non-mutagenic in the bacterial reverse mutation assay.

Executive summary:

The study was performed to evaluate the potential mutagenicity of the test substance in a bacterial reverse mutation assay using S.typhimurium strains TA98, TA100, TA1535, TA1537 and TA102, in both the presence and absence of S9 mix. The study was performed to GLP and was designed to the requirements of OECD guideline 471, EU Method B.13/14 and EPA OPPTS 870.5100. In a preliminary toxicity assay, the maximum dose tested was 5000 ug/plate. Based on the findings of the preliminary toxicity assay, the doses tested were 31.6, 100, 316, 1000, 2500 and 5000 μg/plate in the presence and absence of S9 activation. Positive controls appropriate for each strain, in the presence and absence of S9 mix, were included. Two independent tests were conducted, with experiment 1 employing the use of the plate incorporation method and experiment 2 using the preincubation method.

 

The test substance did not induce any significant, reproducible increases in the observed number of revertant colonies in any of the strains tested, either in the presence or absence of S9-mix. No toxic effects of the test item were noted in any of the strains used up to the highest dose group evaluated with and without metabolic activation in experiment I and II with the exception of a toxic effect observed in tester strain TA 102 in experiment II at a concentration of 5000 μg/plate (without metabolic activation). The reduction in the number of revertants down to a mutation factor of 0.5 found in experiment II in tester strain TA 100 at a concentration of 1000 μg/plate (without metabolic activation) was regarded as not biologically relevant due to lack of a dose-response relationship.The sensitivity of the test system and the metabolic activity of the S9-mix were clearly demonstrated by the increases in the numbers of reverant colonies induced by the positive control substances. It was concluded that, under the conditions of this assay, the test substance gave a negative, i.e. non-mutagenic response in S.typhimurium strains TA98, TA100, TA1535, TA1537 and TA102 in both the presence and absence of S9 mix.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

The study was performed to evaluate the potential mutagenicity of the test substance in a bacterial reverse mutation assay using S.typhimurium strains TA98, TA100, TA1535, TA1537 and TA102, in both the presence and absence of S9 mix. The study was performed to GLP and was designed to the requirements of OECD guideline 471, EU Method B.13/14 and EPA OPPTS 870.5100. In a preliminary toxicity assay, the maximum dose tested was 5000 ug/plate. Based on the findings of the preliminary toxicity assay, the doses tested were 31.6, 100, 316, 1000, 2500 and 5000 μg/plate in the presence and absence of S9 activation. Positive controls appropriate for each strain, in the presence and absence of S9 mix, were included. Two independent tests were conducted, with experiment 1 employing the use of the plate incorporation method and experiment 2 using the preincubation method.

The test substance did not induce any significant, reproducible increases in the observed number of revertant colonies in any of the strains tested, either in the presence or absence of S9-mix. No toxic effects of the test item were noted in any of the strains used up to the highest dose group evaluated with and without metabolic activation in experiment I and II with the exception of a toxic effect observed in tester strain TA 102 in experiment II at a concentration of 5000 μg/plate (without metabolic activation). The reduction in the number of revertants down to a mutation factor of 0.5 found in experiment II in tester strain TA 100 at a concentration of 1000 μg/plate (without metabolic activation) was regarded as not biologically relevant due to lack of a dose-response relationship.The sensitivity of the test system and the metabolic activity of the S9-mix were clearly demonstrated by the increases in the numbers of reverant colonies induced by the positive control substances. It was concluded that, under the conditions of this assay, the test substance gave a negative, i.e. non-mutagenic response in S.typhimurium strains TA98, TA100, TA1535, TA1537 and TA102 in both the presence and absence of S9 mix.

Justification for selection of genetic toxicity endpoint
One study available; GLP compliant and has a Klimisch score 1.

Justification for classification or non-classification

The test substance does not meet classification criteria under EU Directive 67/548/EEC for mutagenicity.

The test substance does not meet classification criteria under Regulation (EC) No 1272/2008 for mutagenicity.