5-hydroxyiminobarbituric acid

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Violuric acid was tested in the reverse mutation assay (Ames Test) using four Salmonella Typhimurium strains (TA1535, TA1537, TA98, TA100) and one 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 and DMSO was used as solvent.

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, 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.

Link to relevant study records

Reference

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

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

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

Species / strain / cell type:

E. coli WP2 uvr A pKM 101

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

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.

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

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

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

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

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

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.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on available data violuric is non-mutagenic and no classification as mutagenic is needed.