Anthranilamide

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian cell study: 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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Version / remarks:

updated and adopted July 21, 1997

GLP compliance:

yes

Type of assay:

mammalian erythrocyte micronucleus test

Test material

Test material information

Constituent 1

Reference substance name:

Anthranilamide

EC Number:

201-851-2

EC Name:

Anthranilamide

Cas Number:

88-68-6

Molecular formula:

C7H8N2O

IUPAC Name:

2-aminobenzamide

Test material form:

solid: particulate/powder

Remarks:

tan

Specific details on test material used for the study:

purity 100%

Test animals

Species:

mouse

Strain:

other: Crl:CD-1 (ICR) BR

Details on species / strain selection:

This is an outbred strain that maximizes genetic heterogeneity and therefore tends to eliminate strain-specific response to test articles.

Sex:

male

Details on test animals or test system and environmental conditions:

Only male mice were used because no substantial difference in toxic signs between the sexes was observed in the dose-range finding study.
Comercial diet and water was available ad libitum. The animals were assigned randomly by a computer program to the study dose groups. Animals were dosed based upon tehe individual animal weights, on an acute(one-time only) basis.
the weight variation of teh animals did not exceed ±20% of teh mean weight of each sex.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

Corn oil

Details on exposure:

Since no appropriate toxicity dat awere available (e.g same species, strain, same route etc.) a dose-range finding study was performed using the same regimen to be used in themicronucleus assay. A dose range of 200 to 2000 mg/kg (200, 500, 800, 1500, 2000) was tested on both sexes. (Three animals per dose group)

As no substantial difference in toxic signs between the sexes was observed in the dose-range finding study, only male mice were used.
The high dose (1200 mg/kg) was chosen to cause toxicity or depression of the ration of PCEs to normochromatic erythrocytes (NCEs). Six animals per dose group were tested, vehicle and positive controls and also a secondary (replacement) dose group of six animals at the high doselevel to be used as substitutes for any deaths.

Duration of treatment / exposure:

One-time only dosing.

Frequency of treatment:

One-time only dosing.

Post exposure period:

Harvest times of approximately 24 and 48 hours were used for the high dose and the vehicle control animals. The mid- and low-dose groups, as well as the positive control animals, were harvested approximately 24 hours after treatment.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

300 mg/kg bw (total dose)

Doses / concentrations 2

Dose / conc.:

600 mg/kg bw (total dose)

Doses / concentrations 3

Dose / conc.:

1 200 mg/kg bw (total dose)

No. of animals per sex per dose:

6

Control animals:

yes, concurrent vehicle

other: replacement animals at high-dose to substitute any deaths

Positive control(s):

cyclophosphamide

Examinations

Tissues and cell types examined:

bone marrow, erythrocytes

Details of tissue and slide preparation:

After euthanisation, the hind limb bines were removed for marrow extraction from teh first five surviving animals. For each animal, the marrow flushed from teh bones was combined in an individual centrifuge tube containing 3 to 5 mL fetal bovine serum.

Following centrifugsation to pellet the bone marrow tissue,the supernatants were removed by aspiration and portions of teh pellets were spread on lsides and air dried. The slides were fixed in methanol, stained in May-Grunwald solution followed by Giemsa, and protected by mounting with overclips.

Evaluation criteria:

Slides prepared from the bone marrow were scored for micronucleated PCEs and PCE:NCE cell ratio. The micronucleus frequency was determined by analyzing the number of micronucleated PCEs from 2000 PCEs per animal. The PCE:NCE ration was determined by scoring teh number of PCEs and NCEs observed in the optic fields while scoring at least teh first 200 erythoricytes on the slide.

Statistics:

Analysis of variance on untrasnformed proportions of cells with micronuclei per animal and on untrasnformed PCE:NCE ratios when teh variances were homogeneous. Ranked proportions were used for heterogeneous variances.

Results and discussion

Test results

Key result

Sex:

male

Genotoxicity:

negative

Toxicity:

yes

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Anthranilamide was found negative in an OECD 474 study in the Mouse, administered by oral gavage conducted under GLP conditions.