5-chloro-1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-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:

2003-07-31 to 2003-09-07

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Non-GLP study conducted with methods similar to OECD Guideline 471 (Bacterial Reverse Mutation Assay) with the following deviations: 1) only three strains were tested; 2) limited information on the test substance and methodological details were presented.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

1) only three strains were tested; 2) limited information on the test substance and methodological details were presented.

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

5-chloro-1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-one

EC Number:

258-771-6

EC Name:

5-chloro-1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-one

Cas Number:

53786-28-0

Molecular formula:

C12H14ClN3O

IUPAC Name:

5-chloro-1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-one

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study reports): T000990
- Physical state: solid (powder)
- Appearance: slight beige powder

Specific details on test material used for the study:

Description: Pale beige powder
Purity: 100 %
Date received: 24 April 2003
Storage conditions: Room temperature in the dark

Method

Target gene:

histidine locus

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA98, TA100 and TA102

Details on mammalian cell type (if applicable):

not applicable

Metabolic activation:

with and without

Metabolic activation system:

10% rat liver S9 in standard co-factors

Test concentrations with justification for top dose:

0, 0.5, 1.5, 5, 15, 50, 150, 500, 1500, and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: no data

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

N-ethyl-N-nitro-N-nitrosoguanidine

Remarks:

Without S9: 3 µg/plate for TA100

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

Without S9: 0.5 µg/plate for TA102

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

Without S9: 0.2 µg/plate for TA98

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

With S9: 1 µg/plate for TA100

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 1,8-dihydroxyanthraquinone

Remarks:

With S9: 10 µg/plate for TA102

Controls 6

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

With S9: 5 µg/plate for TA98

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 3 days

SELECTION AGENT: histidine

NUMBER OF REPLICATIONS: triplicate

DETERMINATION OF CYTOTOXICITY
- Method: reduction in the growth of the bacterial background lawn

Rationale for test conditions:

no data

Evaluation criteria:

no data

Statistics:

no data

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS:
- Effects of pH: no data
- Effects of osmolality: no data
- Evaporation from medium: no data
- Water solubility: no data
- Precipitation: No test substance precipitate was observed on the plates at any of the doses tested in either the presence or absence of S9-mix.

RANGE-FINDING/SCREENING STUDIES: no data

COMPARISON WITH HISTORICAL CONTROL DATA:
The vehicle control plates gave counts of revertant colonies within the normal range (no historical data control tables were provided). All of the positive control substances induced marked increases in the frequency of revertant colonies, both with and without metabolic activation. Thus, the sensitivity of the assay and the efficacy of the S9 mix were validated.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
The test substance caused no visible reduction in the growth of the bacterial background lawn at any dose level. The test substance was, therefore, tested up to the maximum recommended dose level of 5000 µg/plate.

Remarks on result:

other: all strains/cell types tested

Applicant's summary and conclusion

Conclusions:

Interpretation of results:
negative with and without metabolic activation

The test substance was evaluated for mutagenic potential in the Ames test using S. typhimurium strains TA98, TA100 and TA102 in the presence and absence of metabolic activation. The test substance was considered to be non-mutagenic under the conditions of this test.