Methyl N-methylanthranilate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro DNA damage and/or repair study

Remarks:

Type of genotoxicity: DNA damage and/or repair

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed publication

Justification for type of information:

Data is from peer reviewed publication

Data source

Reference

Reference Type:

publication

Title:

The genotoxicity of a variety of aniline derivatives in a DNA repair test with primary cultured rat hepatocytes

Author:

Naoki Yoshimi, Shigeyuki Sugie, Hitoshi Iwata, Kenji Niwa, Hideki Mori, Chise Hashida and Hidesuke Shimizu

Year:

1988

Bibliographic source:

Mutation Research, 206 (1988) 183-191

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: As mention below

Principles of method if other than guideline:

The genotoxicity of N-methylanthranilic acid methyl ester, was examined by a DNA repair test with rat hepatocytes.

GLP compliance:

not specified

Type of assay:

DNA damage and repair assay, unscheduled DNA synthesis in mammalian cells in vitro

Test material

Test material information

Constituent 1

Reference substance name:

Methyl N-methylanthranilate

EC Number:

201-642-6

EC Name:

Methyl N-methylanthranilate

Cas Number:

85-91-6

Molecular formula:

C9H11NO2

IUPAC Name:

methyl 2-(methylamino)benzoate

Method

Target gene:

No data

Species / strain

Species / strain / cell type:

hepatocytes: ACI rat hepatocytes

Details on mammalian cell type (if applicable):

- Type and identity of media: Williams' Medium E
- Properly maintained: No data
- Periodically checked for Mycoplasma contamination: No data
- Periodically checked for karyotype stability: No data
- Periodically “cleansed” against high spontaneous background: No data

Additional strain / cell type characteristics:

not specified

Metabolic activation:

not specified

Metabolic activation system:

No data

Test concentrations with justification for top dose:

10-3, 10-4, 10-5, 10-6 M

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: N-2-fluorenylacetamide

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Preincubation period: No data
- Exposure duration: 20 hrs
- Expression time (cells in growth medium): 20 hrs
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays): No data
SPINDLE INHIBITOR (cytogenetic assays): No data
STAIN (for cytogenetic assays): No data

NUMBER OF REPLICATIONS: Duplicate

NUMBER OF CELLS EVALUATED: 50 cells/coverslip

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data

OTHER EXAMINATIONS:
- Determination of polyploidy: No data
- Determination of endoreplication: No data
- Other: No data

OTHER: The test was performed in accordance with the method of Williams et al. Hepatocytes were isolated from the livers of male ACI rats weighing 200-250 g. The isolated hepatocytes were allowed to attach for 2 h on plastic coverslips in primary culture using Williams' Medium E. The cultures were then washed and exposed to the test chemical and [Me- 3H]thymidine (10 µCi/ml; 49 Ci/mmole) for 20 h. It was logarithmically diluted before addition to the cultures. At the end of incubation, the cultures were washed, and the coverslips were mounted on glass slides. The slides were dipped in Sakura NR-M2 photographic emulsion and exposed for 14 days. Autoradiographic grains were counted on a television screen (Olympus, type S) with a microscopic attachment.

The data were expressed as the average net counts/nucleus for 3 coverslips + the standard deviation (50 cells/coverslip). Two experiments were performed for the test compound for the assays with rat hepatocytes.

Evaluation criteria:

The test chemical was considered positive when the mean net nuclear grain count was more than 5 grains above background and statistically greater than that of controls (unpaired t-test; P < 0.01).

Statistics:

Mean ± standard deviation

Results and discussion

Test results

Species / strain:

hepatocytes: ACI rat hepatocytes

Metabolic activation:

not specified

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

No data available

Remarks on result:

other: strain/cell type:

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Chemical	Dose M	UDS grains/nucleus	% od UDS positive cells	DNA repair
N-methylanthranilic acid methyl ester	10^-3	0.7 ± 1.4	0	-
	10^-4	-0.1 ± 1.5	0
	10^-5	-0.5 ± 1.2	0
	10^-6	-0.5 ± 1.0	0

Applicant's summary and conclusion

Conclusions:

The given test material test substance is negative in the rat hepatocyte/DNA repair test.

Executive summary:

The hepatocyte/DNA repair test which measures unscheduled DNA synthesis (UDS) is known to be sensitive to various classes of DNA-reactive carcinogens and is regarded as a reliable short-term test for the detection of chemical carcinogens.The genotoxicity of test substance, was examined by a DNA repair test with rat hepatocytes.

 

The test was performed basically in accordance with the method of Williams et al. The test material was dissolved in DMSO and the positive control used was N-2-fluorenylacetamide. The hepatocytes were exposed to the test chemical for 20 hrs. At the end of incubation, the cultures were washed, and the coverslips were mounted on glass slides. The slides were dipped in Sakura NR-M2 photographic emulsion and exposed for 14 days. Autoradiographic grains were counted on a television screen (Olympus, type S) with a microscopic attachment.

 

The test chemical was evaluated to be positive only when the mean net nuclear grain count was more than 5 grains above background and statistically greater than that of controls.

 

The results of the hepatocyte/DNA repair test suggests that N-methylanthranilic acid methyl ester is negative for genotoxicity in vitro.