1-amidino-2-thiourea

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1-amidino-2-thiourea

EC Number:

218-308-0

EC Name:

1-amidino-2-thiourea

Cas Number:

2114-02-5

Molecular formula:

C2H6N4S

IUPAC Name:

1-(Diaminomethylidene)thiourea

Test material form:

solid: crystalline

Specific details on test material used for the study:

Supplier: Changzou Foreign Trade Corp.Batch No.: 0041A25 (20141211)Physical state: solid substance, crystalline powderColour: whiteStorage in a cool, dry place, protected from light

Method

Target gene:

Salmonella typhimurium TA98, TA100, TA1535 and TA1537: GCEscherichia coli WP2 uvrA: AT

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

rat liver S9

Test concentrations with justification for top dose:

Based on the results of the preliminary Range Finding Test the following concentrations of the test item were prepared and used in the Initial and Confirmatory Mutation Tests: 5000, 1600, 500, 160, 50 and 16 μg/plate.

Vehicle / solvent:

Dimethyl sulfoxide (DMSO)Ultrapure water (UPW)

Controls

Controls 1

Positive controls:

yes

Positive control substance:

other: 4-Nitro-1,2-phenylenediamine, NPD

Remarks:

4 μg/plate, Salmonella typhimurium TA98, without metabolic activation

Controls 2

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

2 μg/plate, Salmonella typhimurium TA100 and TA1535, without metabolic activation

Controls 3

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

50 μg/plate, Salmonella typhimurium TA1537, without metabolic activation

Controls 4

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

2 μL/plate, Escherichia coli WP2 uvrA, without metabolic activation

Controls 5

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

2 μg/plate for S. typhimurium strains; 50 μg/plate for E. coli WP2 uvrA, Salmonella typhimurium TA98; TA100; TA1535; TA1537 and Escherichia coli WP2 uvrA, with metabolic activation [10 % (v/v) rat liver]

Controls 6

Untreated negative controls:

yes

Remarks:

vehicle Control

Remarks:

DMSO, UPW

Details on test system and experimental conditions:

The study included a Preliminary Solubility Test, a Preliminary Range Finding Test (Informatory Toxicity Test) an Initial Mutation Test (Plate Incorporation Test) and a Confirmatory Mutation Test (Pre-Incubation Test). In the preliminary Range Finding Test as well as in the Initial Mutation Test the plate incorporation method was used. Based on the results of the preliminary tests, a concentrated stock solution was prepared from the test item with Dimethyl sulfoxide (DMSO), which was diluted by serial dilutions to obtain the six dosing solutions investigated in the main tests. The maximum test concentration was in all examined strains 5000 μg test item/plate (±S9 Mix). The AMIDINOTHIOUREA (CAS No. 2114-02-5) concentrations investigated in the Initial and Confirmatory Mutation Tests: 5000, 1600, 500, 160, 50 and 16 μg/plate. Test solutions were freshly prepared at the beginning of the experiment.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

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:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

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:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 1535

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:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 1537

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:

valid

Positive controls validity:

valid

Test results 5

Species / strain:

E. coli WP2 uvr A

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:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

In conclusion, the test item AMIDINOTHIOUREA (CAS No. 2114-02-5) has no mutagenic activity on the applied bacterium tester strains under the test conditions used in this study.