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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Mutagenicity spectra in Salmonella typhimurium strains of glutathione, L-cysteine and active oxygen species
Author:
Glatt H
Year:
1989
Bibliographic source:
Mutagenesis. 4(3): 221-227

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Potassium superoxide
EC Number:
234-746-5
EC Name:
Potassium superoxide
Cas Number:
12030-88-5
Molecular formula:
KO2
IUPAC Name:
potassium superoxide
Test material form:
solid

Method

Target gene:
Histidine
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 92, TA 97, TA 100, TA 102, TA 104, TA 1535, and TA 1537
Metabolic activation:
without
Metabolic activation system:
S9 fractions from male Sprague-Dawley rat kidneys
Test concentrations with justification for top dose:
0, 0.33, 0.67, 1.33, 2.67 and 5.33 µmol/plate
Vehicle / solvent:
neutralized aqueous solution
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
no
Details on test system and experimental conditions:
Method of application: in agar (plate incorporation) + 'Preincubation assay' (20 min incubation in a glass tube)
Number of replications: 3
All strains/cell types tested
Statistics:
Linear regression analysis

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium, other: TA 92, TA 97, TA 100, TA 102, TA 104, TA 1535, and TA 1537
Metabolic activation:
without
Genotoxicity:
positive
Remarks:
Positive in S. typhimurium TA 100, TA 102, and TA 104
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
not applicable
Additional information on results:
Salmonella typhymurium strain TA 104 was the most responsive strain. Marked effects were observed in TA 102 as well. In strain TA 100, the test substance only produced a weak increase in the number of mutants. No mutagenicity was observed in the other strains. The spectra of mutagenicity was similar for KO2, H2O2, and glucose oxidase, all being directly or indirectly generators of reactive oxygen species.

Applicant's summary and conclusion

Conclusions:
Under the study conditions, the substance was found to be mutagenic in Salmonella typhimurium.
Executive summary:

A study was conducted to determine the in vitro genetic toxicity of the substance according to OECD Guideline 471. Salmonella typhimurium strains TA 97, TA 100, TA 102, TA 104, TA 1535, and TA 1537 were treated with the test substance using the plate incorporation method with a 'preincubation assay' (20 min) at concentration ranges of 0 - 5.33 µmol/plate without metabolic activation. The exposure to the test substance produced mutagenic response in S. typhimurium strains TA 100, TA 102, and TA 104, with more marked effects in TA 102 and 104. Salmonella typhimurium strain TA 104 was the most responsive strain. Marked effects were observed in TA 102 as well. In strain TA 100, the test substance only produced a weak increase in the number of mutants. No mutagenicity was observed in the other strains. The strain spectra of the mutagenicity were similar for KO2, H2O2, and glucose oxidase, all being directly or indirectly generators of reactive oxygen species. Under the study conditions, the substance was found to be mutagenic in Salmonella typhimurium (Glatt, 1989).