Benzoic acid, 4-(methylamino)-3-nitro-

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

Reliability:

1 (reliable without restriction)

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 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

4-(methylamino)-3-nitrobenzoic acid

EC Number:

609-904-5

Cas Number:

41263-74-5

Molecular formula:

C8 H8 N2 O4

IUPAC Name:

4-(methylamino)-3-nitrobenzoic acid

Test animals

Species:

mouse

Strain:

NMRI

Sex:

male/female

Administration / exposure

Route of administration:

intraperitoneal

Frequency of treatment:

single

No. of animals per sex per dose:

5 male and female per dose

Control animals:

yes, concurrent vehicle

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

yes

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative
In conclusion, it can be stated that during the study described and under the experimental conditions reported, the test item BIBR 1048 Aminoacido
did not induce structural and/or numerical chromosomal damage in the immature erythrocytes of the mouse.
Therefore, the test item BIBR 1048 Aminoacido is considered to be nonmutagenic with respect to clastogenicity and/or aneugenicity in the
Mammalian Erythrocyte Micronucleus Test.

Executive summary:

This study was performed to investigate the potential of BIBR 1048 Aminoacido to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the mouse, which is the endpoint of this test to assess genotoxicity. The test item was prepared with Cottonseed oil. The volume administered ip was 10 mL/kg bw. Peripheral blood samples were collected for micronuclei analysis

44 h and 68 h after a single application of the test item. A pre-experiment was performed as range finding study based on the OECD guideline 474 and other relevant documents. A dose of 500 mg/kg bw was selected as maximum tolerable dose (MTD). Signs of toxicity were noted. In the main experiment three dose levels were used covering a range from the maximum tolerable dose to slight/or no toxicity. The following dose groups were selected based on the toxicity observed in the pre-experiment:

Doses	Concentration [mg/kg bw]
1 MTD	500 mg/kg bw
0.05 MTD	250 mg/kg bw
0.02 MTD	100 mg/kg bw

The animals treated with a dose of 0.2 MTD and 0.5 MTD showed slight signs of systemic toxicity. The animals treated with a dose of 1 MTD showed signs of systemic toxicity. The signs of toxicity noted were reduction of spontaneous activity, palpebral closure, prone position, constricted opisthosoma and change of the skin colour. For all dose groups, including positive and negative controls, 10000 polychromatic erythrocytes per animal were scored for incidence of micronuc1eated immature erythrocytes. The negative controls (44 h, 68 h) were within the range of the historicallabour control data. The mean values noted for the dose groups which were treated with the test item (44 h, 68 h) were within or decreased compared to the negative control data range. No biologically relevant increase of micronuclei was found after treatment with the test item in any of the dose groups evaluated.

The nonparametric Mann-Whitney test was perfonned to verify the results. No statistically significant enhancement (p<0.05) of cells with micronuclei was noted in any dose group of the test item evaluated (Table 12).

Cyclophosphamide (40 mg/kg bw) administered ip was used as positive control which induced a significant increase in micronucleus frequency. This demonstrates the validity of the assay.