(±)-13-ethyl-3-methoxygona-2,5(10)-dien-17β-ol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Gene mutation (bacterial reverse mutation assay / Ames test): negative with and without metabolic activation [Wollny 1996]

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:

other information

Study period:

January 96

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

- Justification why the confirmation of the negative result is not considered necessary is not provided.

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Target gene:

Histidine gene locus

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital/beta-Naphthoflavone induced male rat liver S9 mix

Test concentrations with justification for top dose:

10.0, 33.3, 100.0, 333.3, 1000.0, 2500.0 and 5000.0 µg/plate

Vehicle / solvent:

DMF

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: without metabolic activation: Sodium azide, 4-Nitro-o-phenylenediamine, Methyl methane sulfonate; with metabolic activation: 2-Aminoanthracene

Details on test system and experimental conditions:

plate incorporation assay

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Moderate toxic effects in strain TA 1535 at 2500 and 5000 µg/plate (+ S9); in strain 1537 at 1000 µg/plate and above (+ S9)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No precipitation of the test article occurred up to the maximal applied dose.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Moderate toxic effeets, evident as a reduction in the number of revertants, occurred in the presence of metabolic activation in strain TA 1535 at 2500 and 5000 µg/plate and in strain TA 1537 at 1000 µg/plate and above.

The plates incubated with the test item showed normal background growth up to 5000 µg/plate with and without S9 mix in all strains used.

No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with the test subsatnce at any concentration level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.

Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies.

Executive summary:

The mutagenic potential of the test substance was evaluated in a Salmonella/microsome test with the S. typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 in the presence and absence of S9 mix according to OECD TG 471. Evidence of mutagenic activity was not seen up to the maximum recommended dose level of 5000 µg/plate. No substantial increases in revertant colony numbers of any of the five tester strains were observed at any dose level in the presence and absence of metabolic activation. There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. Therefore, the test substance was considered to be non-mutagenic in the Salmonella typhimurium reverse mutation assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

The mutagenic potential of the test substance was evaluated in a Salmonella/microsome test with the S. typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 in the presence and absence of S9 mix according to OECD TG 471 [Wollny, 1996]. Evidence of mutagenic activity was not seen up to the maximum recommended dose level of 5000 µg/plate. No substantial increases in revertant colony numbers of any of the five tester strains were observed at any dose level in the presence and absence of metabolic activation. There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. Therefore, the test substance was considered to be non-mutagenic in the Salmonella typhimurium reverse mutation assay.

Justification for selection of genetic toxicity endpoint
Only one study available

Justification for classification or non-classification

Based on the study results a classification according to Directive 67/548/EEC or Regulation (EC) No. 1272/2008 (CLP) is not required.