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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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
10/03/2006 - 21/04/2006
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study performed according to the guideline.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report Date:
2006

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
The appearance of Potassium permanganate was dark violet - purple crystalling powder with bronze lustre.
Appearance at the test facility was recorded as a raisin crystalline powder.

Potassium permanganate has been used as a surrogate for sodium permanganate where data are not available. Read-across from potassium permanganate to sodium permanganate is appropriate from the toxicological point of view as the most toxicologically relevant part of the substances is the same (permanganate). The contribution of the sodium/potassium ions to the toxicity of the respective substances is likely to be minimal. The toxicity of both substances is therefore likely to be very similar and will be dominated by local (site of contact) irritant/corrosive effects and systemic toxicity due to the absorption of manganese ions. This toxicophore similarity is adequate justification for waiving the conduct of specific studies with sodium permanganate and the dossier reflects this waiving proposal by including summaries of read-across studies where appropriate.

Method

Target gene:
Specially constructed strains have a mutation in the his locus and are therefore not able to form colonies on minimal plates without histidine (tryptophan).
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
S9 fraction of rat liver homogenate and a mixture of cofactors
Test concentrations with justification for top dose:
The test substance was dissolved in demineralised water and assayed in doses of 1.5, 5, 15, 50 and 150 ug which were applied to plates in a volume of 0.1 mL. The first mutagenicity tests showed that the 150ug dose per plate was partially toxic for most strains especially in the experiments without metabolic activation. Therefore, in the second experiment, the highest dose was reduced to 100 ug per plate.
Vehicle / solvent:
Demineralised water.
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
untreated control (no solvent)
Negative solvent / vehicle controls:
yes
Remarks:
Demineralised water
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
Migrated to IUCLID6: CAS: 26628-22-8, Aldrich
Untreated negative controls:
yes
Remarks:
untreated control (no solvent)
Negative solvent / vehicle controls:
yes
Remarks:
Demineralised water
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 4-nitro-o-phenylenediamine, CAS: 99-56-9, Aldrich
Untreated negative controls:
yes
Remarks:
untreated control (no solvent)
Negative solvent / vehicle controls:
yes
Remarks:
Demineralised water
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 9-aminoacridine hydrochloride monohydrate (AAc) CAS: 52417-22-8, Merck
Untreated negative controls:
yes
Remarks:
untreated control (no solvent)
Negative solvent / vehicle controls:
yes
Remarks:
Demineralised water
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminofluorene (AF), CAS: 153-78-6, Sigma
Untreated negative controls:
yes
Remarks:
untreated control (no solvent)
Negative solvent / vehicle controls:
yes
Remarks:
Demineralised water
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene (AA) CAS: 613-13-8, Sigma
Untreated negative controls:
yes
Remarks:
untreated control (no solvent)
Negative solvent / vehicle controls:
yes
Remarks:
Demineralised water
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: N-methyl-N'-nitro-N-nitrosoguanidine (MMNG) CAS: 70-25-7
Details on test system and experimental conditions:
Two series of experiments were performed with each strain, without metabolic activation and with a supernatant of rat liver and a mixture of cofactors. Each experiment included the corresponding positive (reference mutagens) and negative controls (untreated control, solvent control). Untreated controls contain no solvent, negative controls contain 0.1 mL of demineralised water.
Evaluation criteria:
The main criterion for evaluation of results was the modified two-fold increase rule which is comparable with that of other statistical methods. When the result is positive, a reproducible dose-effect and/or doubling ratio Rt/Rc is reached.
Statistics:
As above.

Results and discussion

Test resultsopen allclose all
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:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Most of the results showed no substantial increase in the number of revertants against the solvent control (Rt/Rc <2) and also there was no increase in the number of revertants as the dose was increased.
The number of revertants and the Rt/Rc values were low in the experiments with strain TA1535 (-MAI) with metabolic activation (5 ug per plate = 1.4 fold of the negative control value and 50 ug per plate = 1.6 fold of the negative control value). The increase was thought to have been attributed to the fact that the negative control value was the lowest average value in the experiment. A decreasing trend was observed in dose-dependence rather than ascending, especially in the case of the experiment with 150 ug per plate, which could be attributed to the toxicity of the substance at the higher doses. These results were not confirmed by the parallel experiment.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

No additional information.       

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Results showed that Potassium permanganate was nonmutagenic for all the used bacterial strains tested with and without metabolic activation.
Executive summary:

The mutagenicity of potassium permanganate was investigated in an Ames test using S. typhimurium TA98, TA100, TA1535 and TA1578 and in E. coli WP2 uvrA. Triplicate cultures were exposed to the test material (dissolved in water) at concentrations of 1.5 -100 ug/plate (cytototoxic concentration) in the presence and absence of an exogenous source of metabolic activation. Solvent controls, negative controls and appropriate positive controls were also used. Exposure to the test substance did not induce and significant increase in revertant colonies. A slight increase seen in mutation frequency at an intermediate concentration with strain TA1535 (1.6x control value; +S9) is not considered to be relevant in the absence of a concentration response or any reproducibility. Results were confirmed in an independently repeated assay and the sensitivity demonstrated by appropriate responses to positive control compounds.