Benzenesulfonamide, N-(4-hydroxyphenyl)-

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

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:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: USA, EPA OCSPP harmonized guideline - Bacterial Reverse Mutation Test

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Economy, Trade and Industry, Japanese Ministry of Health, Labour and Welfare and Japanese Ministry of Agriculture, Forestry and Fisheries.

Principles of method if other than guideline:

no deviations

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

N-(4-hydroxyphenyl)benzenesulfonamide

EC Number:

654-333-7

Cas Number:

5471-90-9

Molecular formula:

C12 H11 N O3 S

IUPAC Name:

N-(4-hydroxyphenyl)benzenesulfonamide

Test material form:

not specified

Details on test material:

94.63% purity

Method

Target gene:

All of the Salmonella strains are histidine dependent by virtue of a mutation through the histidine operon and are derived from S. typhimurium strain LT2 through mutations in the histidine locus. Additionally they posses a faulty lipopolysaccharide coat to the bacterial cell surface thus increasing the cell permeability to larger molecules. A further mutation, through the deletion of uvrB-Bio gene, causes an inactivation of the excision repair system and a dependence on exogenous biotin.
Strains TA98 and TA100: R-factor plasmid pKM101
E. coli: mutation in tryptophan + uvrA- DNA repair deficiency

Species / strain

Species / strain 1

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

checked for characteristics, viability and spontaneous reversion rate (all were found to be satisfactory).

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Details on mammalian cell type (if applicable):

checked for characteristics, viability and spontaneous reversion rate (all were found to be satisfactory).

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

Eight concentrations of the test item (1.5, 5, 15, 50, 150, 500, 1500 and 5000 microgram/plate) were assayed in triplicate.

Vehicle / solvent:

dimethyl sulphoxide: the test item was fully soluble at 50 mg/mL.

Controls

Untreated negative controls:

yes

Remarks:

2AA for TA100, TA1535 and TA1537; BP for TA98

Positive controls:

yes

Remarks:

ENNG for WP2uvrA, TA100 and TA1535; 9AA for TA1537, 4NQO for TA98

Details on test system and experimental conditions:

All plates were incubated at 37°C +- 3°C for appr. 48 hours.

NUMBER OF REPLICATIONS: 3

Evaluation criteria:

/

Statistics:

/

Results and discussion

Test results

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:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

/

Applicant's summary and conclusion

Conclusions:

CH03951 was considered to be non-mutagenic under the conditions of this test.

Executive summary:

SUMMARY

Introduction

The test method was designed to be compatible with the guidelines for bacterial mutagenicity testing published by the major Japanese Regulatory Authorities including METI, MHLW and MAFF, the OECD Guidelines for Testing of Chemicals No. 471 "Bacterial Reverse Mutation Test", Method B13/14 of Commission Regulation (EC) number 440/2008 of 30 May 2008 and the USA, EPA OCSPP harmonized guideline - Bacterial Reverse Mutation Test except that a replicate assay was not performed.

Methods.......

Salmonella typhimurium strains TA1535, TA1537, TA98 and TA100 andEscherichia colistrain WP2uvrAwere treated with the test item using the Ames pre-incubation method at eight dose levels, in triplicate, both with and without the addition of a rat liver homogenate metabolizing system (10% liver S9 in standard co-factors). The dose range for the test was predetermined and was 1.5 to 5000g/plate.

Results.......

The vehicle (dimethyl sulphoxide) control plates gave counts of revertant colonies within the normal range. All of the positive control chemicals used in the test induced marked increases in the frequency of revertant colonies, both with or without metabolic activation. Thus, the sensitivity of the assay and the efficacy of the S9-mix were validated.

The maximum dose level of the test item used in the test was selected as the maximum recommended dose level of 5000 μg/plate. The test item induced a visible reduction in the growth of the bacterial background lawns of all of the tester strains, initially from 1500 μg/plate (TA1537 (absence and presence of S9) and TA98 (absence of S9-mix only)) and at 5000 μg/plate (remaining tester strains in the presence/absence of S9-mix) No test item precipitate was observed on the plates at any of the doses tested in either the presence or absence of S9-mix.

There were no significant increases in the frequency of revertant colonies recorded for any of the bacterial strains, with any dose of the test item, either with or without metabolic activation in a single Experiment performed using pre-incubation methodology.

Conclusion

CH03951/BK was considered to be non-mutagenic under the conditions of this test.