Registration Dossier

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

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
Study period:
2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study generated according to internationally accepted testing guidelines.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
HIS- to HIS+ reversions
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
other: Histidine operon mutated
Metabolic activation:
with and without
Metabolic activation system:
S9 activated
Test concentrations with justification for top dose:
10, 20, 40, 60, 80 and 100% of test material
Vehicle / solvent:
Solution 0.9% w/v NaCl or DMSO
Controls
Untreated negative controls:
yes
Remarks:
Negative controls (extraction medium and Aqua destilled) were treated in the same way as the treatment groups.
Positive controls:
yes
Remarks:
Strain specific positive controls were included in the assay. Without metabolic activation: TA 100, TA 1535: NaN3, sodium azide, 10μg/plate / TA 98, TA 1537: 4-NOPD, 4-nitro-o-phenylene-diamine, 10μg/plate for TA 98, 40μg/plate for TA 1537 / TA 102: MMS
Details on test system and experimental conditions:
S typhimurium strains TA 98, TA 100, TA1535, TA1537 and TA102 in nutrient broth at the late exponential or early statonary phase of growth
with or without metabolic activation (S9 substitution buffer/ S9 mix respectively)
Evaluation criteria:
The mutation factor is calculated by dividing the mean value of the revertant counts through the mean values of the extract medium control
a test item is considered mutagenic if
-a clear and dose related increase in the number of revertants occurs
-and/or a biologically relevant positive response for at least one of the dose groups occurs
Statistics:
According to OECD guidelines the biological relevance is the criterion for the interpretation of results and a statistical evaluation is not regarded necessary

Results and discussion

Test results
Species / strain:
other: S.Typhimurium strains, TA 98, TA 100, TA 1535, TA 1537 and TA 102
Metabolic activation:
with and without
Genotoxicity:
not determined
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
Cytotoxicity was noted for TA98 without activation for concentrations >/80%, for TA100 without activation for concentrations >/ 60%, for TA1535 without activation for concentrations >/ 80%, for TA1537 without activation for concentrations>/ 80%, for TA102
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
In Experiment I: (polar extracts)
10, 20, 40, 60, 80 and 100% extracts of test item in 0.9% NaCl were used as well as 5% extracts for TA100 and TA1535 without metabolic activation
Cytotoxicity was noted for TA98 without activation for concentrations >/80%, for TA100 without activation for concentrations >/ 60%, for TA1535 without activation for concentrations >/ 80%, for TA1537 without activation for concentrations>/ 80%, for TA102 with and without activation for concentrations >/ 80%.
Experiment II: (non polar metabolites)
no cytotoxicity was noted
no biologically relevant increases in revertant colony numbers in any strains used up to the highest extract concentrations were noted
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Additional information on results and controls are included in the attached document

Applicant's summary and conclusion

Conclusions:
when S typhimurium was incubated with extracts of the test item, no biologically relevant increases in revertant colony numbers in any strains used up to the highest extract concentrations were noted
Executive summary:

Ames test was performed on five S typhimurium strains (TA 98, TA 100, TA1535, TA1537 and TA102) with or without metabolic activation according to OECD 471. The test item was diluted either in 0.9% NaCl in water ir in DMSO to final concentrations of 10, 20, 40, 60, 80 and 100%. In extracts in water (experiment I) toxic effects were noted in all tester strains at concentrations 60% or higher whereas no cytotoxicity was noted in experiment II (with DMSO). No biologically relevant increase in revertant colonies were observed following treatment with polar or non-polar extracts of the test item at any concentration level neither in the presence or absence of metabolic activation. The reference mutagens caused an distinct increase confirming the validity of the experiment. It can be deduced that the test item is not mutagenic for bacteria under the present experimental conditions.