4,4'-[(3,3'-dichloro[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[2,4-dihydro-5-methyl-2-(p-tolyl)-3H-pyrazol-3-one]

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

Study period:

From 2 Nov 2007 to 5 Dez 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD 471 with Prival modification for Azo Dyes), GLP compliant

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

4,4'-[(3,3'-dichloro[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[2,4-dihydro-5-methyl-2-(p-tolyl)-3H-pyrazol-3-one]

EC Number:

239-898-6

EC Name:

4,4'-[(3,3'-dichloro[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[2,4-dihydro-5-methyl-2-(p-tolyl)-3H-pyrazol-3-one]

Cas Number:

15793-73-4

Molecular formula:

C34H28Cl2N8O2

IUPAC Name:

4,4'-[(3,3'-dichlorobiphenyl-4,4'-diyl)didiazene-2,1-diyl]bis[5-methyl-2-(4-methylphenyl)-2,4-dihydro-3H-pyrazol-3-one]

Test material form:

solid: nanoform

Method

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Metabolic activation system:

Rat liver S9 from Phenobarbital/ß-Naphthoflavone induced Wistar rats and hamster liver S9

Test concentrations with justification for top dose:

Pre-Experiment/Experiment 1: 0, 3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate
Experiment 2: 0, 3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: because of its solubility properties and its relative non-toxicity to the bacteria

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 1535 and TA100 without metabolic activation

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-Nitro-o-phenylene-diamine

Remarks:

TA1537 and TA98 without metabolic activation

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

WP2 uvrA without metabolic activation

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-Aminoanthracene

Remarks:

all strains with metabolic activation by rat liver S9 and TA 1535, TA1537, TA 100 and WP2 uvrA with metabolic activation by hamster liver S9

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

congo red

Remarks:

TA98 with metabolic activation by hamster liver S9

Details on test system and experimental conditions:

METHOD OF APPLICATION: experiment 1 in agar (plate incorporation); preincubation only in experiment 2 with hamster S9 mix: Prival modification

DURATION
- Preincubation period: 30 min at 30 °C (only experiment 2)
- Exposure duration: at least 48 h at 37 °C

SELECTION AGENT (mutation assays): histidine (Salmonella), tryptophan (E.coli)

DETERMINATION OF CYTOTOXICITY
- Method: other: reductions of spontaneous revertants or cleaning of background lawn

Evaluation criteria:

The Salmonella typhimurium and Escherichia coli reverse mutation assay is considered
acceptable if it meets the following criteria:
- regular background growth in the negative and solvent control
- the spontaneous reversion rates in the negative and solvent control are in the range of our historical data
- the positive control substances should produce a significant increase in mutant colony frequencies

A test item is considered as a mutagen if a biologically relevant increase in the number of revertants exceeding the threshold of twice (strains TA 98, TA 100, and WP2 uvrA) or thrice (strains TA 1535 and TA 1537) the colony count of the corresponding solvent control is observed.
A dose dependent increase is considered biologically relevant if the threshold is exceeded at more than one concentration.
An increase exceeding the threshold at only one concentration is judged as biologically relevant if reproduced in an independent second experiment.
A dose dependent increase in the number of revertant colonies below the threshold is regarded as an indication of a mutagenic potential if reproduced in an independent second experiment. However, whenever the colony counts remain within the historical range of negative and solvent controls such an increase is not considered biologically relevant.

Statistics:

not required

Results and discussion

Test results

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

Precipitation in test tubes at >= 2500 µg/plate samples in both experiments
Precipitation in overlay agar at >= 333 µg/plate in experiment 1 and >= 1000 µg/plate in experiment 2
Reduction of number of revertants in
experiment 1: in TA1535 at >= 2500 µg/plate, in TA1537 and TA98 at 5000 µg/plate without S9; in TA1537 at 5000 µg/plate and in TA98 at >= 1000 µg/plate with S9
experiment 2: no cytotoxicity observed

No toxic effects, evident as a reduction in the number of revertants, were observed with and without metabolic activation in all strains in experiment II. A minor reduction in the number of revertants, was observed only in experiment I in strains TA 1535, TA 1537 and TA 98 in the absence of metabolic and in strains TA 1537 and TA 98 in the presence of metabolic activation at higher concentrations.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Under the conditions of this study the test item was not mutagenic to bacteria.

Executive summary:

This study was performed to investigate the potential of the test item to induce gene mutations according to the plate incorporation assay with rat liver S9(experiment I) and the pre-incubation test with hamster liver S9 (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100, and the Escherichia coli strain WP2 uvrA.

The assay was performed in two independent experiments with and without liver microsomal activation. Each concentration, including the controls, was tested in triplicate. The test item was tested at the following concentrations: Pre-Experiment/Experiment I and II: 3; 10; 33; 100; 333; 1000; 2500; and 5000 µg/plate.

The plates incubated with the test item showed normal background growth up to 5000 µg/plate with and without metabolic activation in both experiments.

No toxic effects, evident as a reduction in the number of revertants, were observed with and without metabolic activation in all strains in experiment II. A minor reduction in the number of revertants, was observed only in experiment I in strains TA 1535, TA 1537 and TA 98 in the absence of metabolic and in strains TA 1537 and TA 98 in the presence of metabolic activation at higher concentrations. No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with the test item at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.

Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies.