2-nitro-p-phenylenediamine

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:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

publication

Title:

Comparison of the mutagenic specificity induced by four nitro-group-containing aromatic amines in Salmonella typhimurium his genes

Author:

King-Thom Chung, Thomas J. Hughes , Larry D. Claxton

Year:

2000

Bibliographic source:

Mutation Research, 465, 2000. 165–171

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

2NPD previously was shown to be direct-acting mutagens in S. typhimu rium strain TA100. In this study, the compoundwere further tested for mutagenicity on Xenometrix strains of S. typhimurium TA7001 and TA7003.

GLP compliance:

no

Type of assay:

bacterial gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-nitro-p-phenylenediamine

EC Number:

226-164-5

EC Name:

2-nitro-p-phenylenediamine

Cas Number:

5307-14-2

Molecular formula:

C6H7N3O2

IUPAC Name:

2-nitrobenzene-1,4-diamine

Constituent 2

Reference substance name:

2-nitro-p-phenylene diamine

IUPAC Name:

2-nitro-p-phenylene diamine

Details on test material:

Name of test material (as cited in study report):2 nitro p phenylene diamine (2NPD)Substance type: OrganicPhysical state: SolidPurchased from Sigma Chemical Company

Method

Target gene:

Plate incorporation

Species / strain

Species / strain / cell type:

other: Xenometrix strains of S. typhimurium TA7001 and TA7003

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Test concentrations with justification for top dose:

600, 900,1200,1500,1800µg/plate

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4NQO = 4-nitroquinoline-N-oxide; MMS = methylmethane sulfonate; Anth = anthramine

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; in agar (plate incorporation); preincubation; in suspension; as impregnation on paper diskAgar plateNUMBER OF REPLICATIONS: triplicate platesOTHER EXAMINATIONS:This research uses these strains to examine the mutational specificity of the aromatic amines 2NPD,3NPD, 4NPD, and DNBA which had been shown to cause mis-sense mutations in Salmonella tester strain TA100.The predominant mutational types were CG – TA transitions and CG - AT transversions

Evaluation criteria:

Test compounds were judged to be positive when they showed a significant dose response trend and fulfilled other requirements for an adequate assay. The Xenometrix strains produce low spontaneous counts; however, the control means do vary from assay to assay. Because of these factors and because the authors do not yet have an extensive historical database for control values, an absolute increase of 10 colonies was required in addition to the significant dose response. Those responses, demonstrating a significant dose–response trend and not showing the required increase, were classified as borderline. Unless otherwise noted, the discussion will assume that the borderline results are equivalent to nonmutagenic results.

Statistics:

The mean ± standard deviation of the numbers of revertant colonies from a final definitive experiment

Results and discussion

Test results

Species / strain:

other: Xenometrix strains of S. typhimurium TA7001 and TA7003

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No data

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'. Remarks: Bacteria tester strains

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):negative with and without2NPD was detected to be non mutagenic for the strains TA7001 and TA7003.

Executive summary:

2-nitro-p-phenylenediamine (2NPD) is a direct-acting mutagen in Salmonella typhimurium strain TA100. The compound was tested further using the Xenometrix strains of S. typhimurium: TA7001 and TA7003, with and without S9 mix in the plate incorporation assay. Each of the strains detects only one unique base substitution event and only that event.

 

The standard S. typhimurium plate incorporation assay was used in this study. Mixtures of cell suspension(100µl), sample solution(up to 100ml)the 0.1 M sodium phosphate buffer, and the Aroclor - induced rat liver S9_7%. _500ml.were added to the top agar and the mixtures were poured onto the bottom agar. All experiments were performed with triplicate plates at five doses. The slope of the dose–response curvethe number of revertants per microgram was calculated by least-squares linear regression from the first linear portion of the dose– response curve using the GeneTox Manager software. The data represent the mean±standard deviation of the numbers of revertant colonies from a final definitive experiment.

 

The compound was non mutagenic to TA7001 and TA7003.

As per the CLP classification, the test material is not likely to classify for gene mutation in vitro.