Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2020-11-24 - 2021-05-11
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2021
Report date:
2021

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

1
Chemical structure
Reference substance name:
By-product from Guanidinoacetic acid manufacturing
EC Number:
951-773-4
Molecular formula:
- Hydantoic Acid Sodium salt: C3H5N2O3Na - Cyanoguanidine: C2H4N4 - Sodium acetate: C3H3O2Na - Glycine: C2H5NO2 - N,N'-Guanidinodiacetic acid: C5H9N3O4 - N,N-Guanidinodiacetic acid: C5H9N3O4 - Guanidinoacetic acid:C3H7N3O2 - Urea: CH4N2O - Water: H2O - Biguanidinoacetic acid: C4H10N6O2 - Sodium formate: CHO2Na - Glycylglycine: C4H8N2O3
IUPAC Name:
By-product from Guanidinoacetic acid manufacturing
Test material form:
solid
Specific details on test material used for the study:
Batch-No.: 201009MA2 solid

Method

Target gene:
histidine operon
Metabolic activation:
with and without
Metabolic activation system:
Mammalian Microsomal Fraction S9 Mix
Test concentrations with justification for top dose:
31.6, 100, 316, 1000, 2500 and 5000 μg/plate
The recommended maximum test concentration for soluble
non-cytotoxic substances is 5 mg/plate or 5 μl/plate
Vehicle / solvent:
A. dest.
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
sodium azide
methylmethanesulfonate
other:
Details on test system and experimental conditions:
TA98: his D 3052; rfa-; uvrB-; R-factor: frame shift mutations
TA100: his G 46; rfa-; uvrB-; R-factor: base-pair substitutions
TA1535: his G 46; rfa-; uvrB-: base-pair substitutions
TA1537: his C 3076; rfa-; uvrB-: frame shift mutations
E. coli: WP2 uvrA (pKM101): trp-; uvrA-: base-pair substitutions

Incubation: 37 °C for at least 48 h in the dark
Evaluation criteria:
Cytotoxicity can be detected by a clearing or rather diminution of the background lawn (indicated as "N" or “B”, respectively in the result tables) or a reduction in the number of revertants down to a mutation factor of approximately ≤ 0.5 in relation to the solvent control.

The Mutation Factor is calculated by dividing the mean value of the revertant counts by the mean values of the solvent control (the exact and not the rounded values are used for calculation).
A test item is considered as 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
in at least one tester strain with or without metabolic activation.
Statistics:
A statistical evaluation of the results is not regarded as necessary

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 98
Remarks:
Plate-incorporation Test
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Remarks:
Plate-incorporation Test
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1535
Remarks:
Plate-incorporation Test
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Remarks:
Plate-incorporation Test
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
E. coli WP2 uvr A pKM 101
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 98
Remarks:
Pre-incubation Test
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Remarks:
Pre-incubation Test
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1535
Remarks:
Pre-incubation Test
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Remarks:
Pre-incubation Test
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
E. coli WP2 uvr A pKM 101
Remarks:
Pre-incubation Test
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
True negative controls validity:
not examined
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, By-product from Guanidinoacetic acid manufacturing did not cause gene mutations by base pair changes or frameshifts in the genome of the tester strains used.
Therefore, By-product from Guanidinoacetic acid manufacturing is considered to be non-mutagenic in this bacterial reverse mutation assay.
Executive summary:

The test item By-product from Guanidinoacetic acid manufacturing was investigated for its potential to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and tester strain E. coli WP2 uvrA (pKM101).
In two independent experiments several concentrations of the test item were used. Each assay was conducted with and without metabolic activation. The concentrations, including the controls, were tested in triplicate. The following concentrations of the test item were prepared and used in the experiments:
31.6, 100, 316, 1000, 2500 and 5000 μg/plate
No precipitation of the test item was observed in any tester strain used in experiment I and II (with and without metabolic activation).
No toxic effects of the test item were noted in any of the five tester strains used up to the highest dose group evaluated with and without metabolic activation in experiment I and II.
No biologically relevant increases in revertant colony numbers of any of the five tester strains were observed following treatment with By-product from Guanidinoacetic acid manufacturing at any concentration level, neither in the presence nor absence of metabolic activation in experiment I and II.
All criteria of validity were met.