5-hydroxyiminobarbituric acid

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 September 2016 to 25 November 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Following GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

21 July 1997

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

5-hydroxyiminobarbituric acid

EC Number:

201-741-4

EC Name:

5-hydroxyiminobarbituric acid

Cas Number:

87-39-8

Molecular formula:

C4H3N3O4

IUPAC Name:

5-(hydroxyimino)-1,3-diazinane-2,4,6-trione

Test material form:

solid: particulate/powder

Details on test material:

Lot/batch No.: 201713807

Specific details on test material used for the study:

CAS: 87-39-8
Purity: ≥ 98%
Manufacturing date: 01/07/2016
Expiry date: 2 years
Lot no: 201616909T

Method

Species / strain

Species / strain 1

Species / strain / cell type:

E. coli WP2 uvr A pKM 101

Species / strain 2

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

S9 homogenate

Test concentrations with justification for top dose:

Based on the initial cytotoxicity test the concentrations of 0.05, 0.16, 0.5, 1.6 and 5 mg/plate were selected

Vehicle / solvent:

Dimethyl sulphoxide

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

2-nitrofluorene

sodium azide

other: 2-aminoanthracene

Remarks:

2-aminoanthracene for trials with metabolic activation, the remaining controls are for trial without metabolic activation

Details on test system and experimental conditions:

Plates were incubated for 72 hours at 37 degrees Celsius

Statistics:

Not performed.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

2.2-19.5 fold incease in numbers of revertant/plate

Test results 2

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

2.2-19.5 fold incease in numbers of revertant/plate

Test results 3

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

2.2-19.5 fold incease in numbers of revertant/plate

Test results 4

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

2.2-19.5 fold incease in numbers of revertant/plate

Test results 5

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

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

2.2-19.5 fold incease in numbers of revertant/plate

Additional information on results:

From the experimental results obtained, the mean numbers of revertant colonies at the tested concentrations were comparable to those of the vehicle control, in both trials, in the presence and absence of metabolic activation. There was no appreciable increase in the number of revertant colonies at any of the tested concentrations in both the trials. The number of revertant colonies in the positive controls resulted in 2.2 to 19.5 fold increase under identical conditions

Applicant's summary and conclusion

Conclusions:

Based on the results obtained in this study, it was concluded that Violuric acid is non-mutagenic in the bacterial reverse mutation test, when tested up to 5 mg/plate in accordance to OECD 471.

Executive summary:

Violuric acid was tested in the reverse mutation assay (Ames Test) using Salmonella Typhimurium strains (TA1535, TA1537, TA98, TA100) and Escherichia Coli strain (WP2uvrA). The test was performed in accordance with OECD test guideline 471 using the plate incorporation and pre-incubation methods at five dose levels, both with and without the addition of rat liver homogenate metabolising system (S9 in standard co-factors). The dose range was determined from the result of a preliminary toxicity and cytotoxicity assay. The selected dose range was 0.05, 0.16, 0.50, 1.6 and 5 mg/plate.

No toxicological significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, at any dose of violuric acid, either with or without metabolic activation per exposure method, hence violuric acid was found to be non-mutagenic. Positive and negative controls included in the study was found to be in accordance to historical control data thus validating the study.