Anthranilic acid

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well performed GLP and OECD guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Anthranilic acid

EC Number:

204-287-5

EC Name:

Anthranilic acid

Cas Number:

118-92-3

Molecular formula:

C7H7NO2

IUPAC Name:

2-aminobenzoic acid

Test animals

Species:

mouse

Strain:

ICR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Strain specifics: ICR
- Source: Harlan Sprague Dawley, Inc., Frederick, MD
- Age at study initiation: 6-8 weeks
- Weight at study initiation: males: 28.2 - 36.6 g, females: 24.0 - 38.5 g (micronucleus assay)
- Housing: in groups of five in plastic autoclavable cages with filter topx.in fully air-conditioned room, heat-treated hardwood chips
- Diet (e.g. ad libitum): rodent chow (Purina Certified Rodent Chow 5002), ad libitum
- Water (e.g. ad libitum): tap water in plastic bottles, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 74 ± 6 °F
- Humidity (%): 50 ± 20 %
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: 1 % sodium carboxymethyl cellulose
- Amount of vehicle (if gavage or dermal): 20 ml/kg body weight

Duration of treatment / exposure:

treatment: once orally
exposure: animals were killed 24 or 48 h after administration
positive control: 24 h

Frequency of treatment:

once

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
750 mg/kg bw male; 600 mg/kg bw female
Basis:
nominal conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
1500 mg/kg bw male; 1200 mg/kg bw female
Basis:
nominal conc.

Doses / concentrations 3

Remarks:

Doses / Concentrations:
3000 mg/kg bw male; 2400 mg/kg bw female
Basis:
nominal conc.

No. of animals per sex per dose:

5 males and 5 females per low and medium dose group, 23 males and 23 females for high dose group

Control animals:

yes, concurrent vehicle

Positive control(s):

60 mg/kg body weight cyclophosphamide (Endoxan (R), 5 males and 5 females); dissolved in distilled water

Examinations

Tissues and cell types examined:

polychromatic and normochromatic erythrocytes from the femoral bone marrow of each animal

Evaluation criteria:

1000 polychromatic erythrocytes were counted for each animal. The number of cells with micronuclei was recorded. As a control measure 1000 mature erythrocytes were also counted and examined for micronuelei. In addition, the ratio of polychromatic to normochromatic erythrocytes was determined. The number of polychromatic erythrocytes with micronucIei occurring in the 1000 polychromatic erythrocytes counted, and the number of normocytes with micronuclei occurring in the 1000 normocytes counted, were evaluated statistically; comparison of dose groups with the simultaneous control group was performed according to Wilcoxon (paired, one-sided, increase) .
The results of the treatment groups (test substance) in the micronucleus test at each dose and killing time were compared with corresponding control values.The ratio of polychromatic to normochromatic erythrocytes was also evaluated statistically by the method of Wilcoxon (paired, two sided). All statistical results are based on a 95% level of significance. Actual data were also compared with historical controls.

Statistics:

Statistical significance was determined using the Kastenbaum-Bowman tables
All statistical results are based on a 95% level of significance.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

yes

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

At high dose levels 12/23 (male) and 14/23 (female) mortality was observed. The following signs of toxicity were observed at medium and high dose levels: lethargy

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative
Oral administration of the test item did not lead to a substantial increase of micronucleated polychromatic and normochromatic erythocytes and was not mutagenic in the in vivo micronucleus test

Executive summary:

The test item was tested in the micronucleus test according to OECD 474. The substance was dissolved in sodium carboxymethyl cellulose and dosed once orally at doses of 750, 1500, 3000 mg per kg bodyweight to male and 600, 1200, 2400 mg/kg bw female mice, upon the results of the previously conducted dose range finding assay. The animals were killed 24 or 48 h after administration.

The number of polychromatic and normochromatic erythrocytes containing micronuclei was not increased. The ratio of polychromatic/normochromatic erythrocytes in both male and female animals remained unaffected by the treatment with the test item and was statistically not different from the control values.

Endoxan^Rwas used as positive control substance and was administered orally at a dose of 60 mg per kg bodyweight.

Endoxan^R induced in both males and females a marked statistically significant increase in the number of polychromatic cells with micronuclei, indicating the sensitivity af the system. The ratio of polychromatic erythrocytes to normocytes was not changed to a significant extent.

The results indicate that, under the conditions of the present study, the test item is not mutagenic in the micronucleus test.