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Toxicological information

Genetic toxicity: in vivo

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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:
weight of evidence
Study period:
June-July 1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Well conducted study according to GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.12 (Mutagenicity - In Vivo Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
Principles of method if other than guideline:
The effect of 1,3-bis(3-methyl-2,5-dioxo-1H-pyrrolinylmethyl)benzene on chromosome structure in bone marrow cells was investigated following acute oral administration to mice. Chromosome damage was measured indirectly by counting micronuclei.
GLP compliance:
yes
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Batch no: BOM pp2
Purity: 87 ± 3% (m/M); see CoA attacahed
Other: m-Xylylene bis (itaconimide): 2-5%

Test animals

Species:
mouse
Strain:
CD-1
Sex:
male/female

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Duration of treatment / exposure:
single application
Frequency of treatment:
single application
Post exposure period:
24h after treatment for all treatment groups and additionally 48 and 72 h after treatment for 2500 and 3000 mg/kg bw groups
Doses / concentrationsopen allclose all
Dose / conc.:
0 other: mg/kg
Remarks:
vehicle control; Sacrifice time: 24, 48, 72 hours
Dose / conc.:
750 other: mg/kg
Remarks:
Sacrifice time: 24 hours
Dose / conc.:
1 500 other: mg/kg
Remarks:
Sacrifice time: 24 hours
Dose / conc.:
2 500 other: mg/kg
Remarks:
Sacrifice time: 24, 48, 72 hours
Dose / conc.:
3 000 other: mg/kg
Remarks:
Sacrifice time: 24, 48, 72 hours
No. of animals per sex per dose:
Range finding: 750, 1500, 3000 and 5000 mg/kg bw

Main study: 5 mice/sex/group
0 mg/kg (vehicle control); Sacrifice time: 24, 48, 72 hours
750 mg/kg; Sacrifice time: 24 hours
1500 mg/kg; Sacrifice time: 24 hours
2500 mg/kg; Sacrifice time: 24, 48, 72 hours
3000 mg/kg; Sacrifice time: 24, 48, 72 hours
Control animals:
yes, concurrent vehicle
Positive control(s):
30 mg/kg chlorambucil

Examinations

Tissues and cell types examined:
Bone marrow smears were prepared and stained for examination; 2000 erythrocytes per animals were analysed for the presence of micronuclei; the ratio of polychromatic versus normochromatic cells was calculated.
Evaluation criteria:
The test material will be designated an in vivo clastogen if a statistically and biologically significant increase in micronucleated polychromatic cells, compared to vehicle contro values, is seen in at least one treatment group, particularly if supported by evidence of a dose-related response.
Statistics:
Mann-Whitney U procedure, two-tailed test

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
see below
Vehicle controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

One male animal treated with BCI-MX at 3000 mg/kg was killed in extremis approximately 2 hours after dosing as a result of hunched posture, piloerection, inactivity and slow respiration. Another male animal dosed with BCI-MX at 2500 mg/kg was found dead approximately 4 hours after dosing, having previously showed signs of hunched posture and inactivity. All other animals survived to scheduled termination, although some animals dosed at 1500, 2500 and 3000 mg/kg showed intermittent signs throughout the study, inclUding hunched posture, piloerection, ungroomed fur at the base of the tail, reduced activity, and redness and swelling in the anal region.

There was some evidence of bone marrow toxicity, as evidenced by depression of bone marrow proliferation, on slides prepared from animals dosed with BCI-MX at 3000 mg/kg and sacrificed 48 or 72 hours later. Frequencies of micronucleated polychromatic erythrocytes in animals killed 24, 48 or 72 hours after administration of BCI-MX were similar to those in concurrent controls. This lack of treatment-related effect was apparent in both sexes, and was confirmed by statistical analysis. Statistically significant increases over controls were, however, seen in positive control group animals given chlorambucil at 30 mg/kg (p<0.01). It is concluded that, under the conditions of test, there was no evidence of induced chromosomal or other damage leading to micronucleus formation in polychromatic erythrocytes of treated mice 24, 48 or 72 hours after oral administration of BCI-MX. The test procedure was highly sensitive to the chromosome-damaging action of chlorambucil.

Applicant's summary and conclusion

Conclusions:
Interpretation of results: negative
Executive summary:

In an in vivo mouse bone marrow micronucleus test performed according to OECD 474 (1983) male and female mice were given a single oral dose of the test substance in corn oil at 750, 1500, 2500 or 3000 mg/kg bw. Five males and five females from each group were killed 24 hours after treatment; further lots of five males and- five females given corn oil or 2500 or 3000mg/kg bw were killed 48 and 72 hours after treatment.

Besides on male in the 3000 and 2500 mg group each, all other animals survived to scheduled termination, although some animals dosed at 1500, 2500 and 3000 mg/kg showed intermittent clinical signs throughout the study, including hunched posture, piloerection, reduced activity, and redness and swelling in the anal region.

There was some evidence of bone marrow toxicity, as seen by depression of bone marrow proliferation on slides prepared from animals dosed with 3000 mg/kg and sacrificed 48 or 72 hours later. Frequencies of micronucleated polychromatic erythrocytes in animals killed 24, 48 or 72 hours after administration of the test substance were similar to those in concurrent controls. It is concluded that, under the conditions of test, there was no evidence of induced chromosomal leading to micronucleus formation in polychromatic erythrocytes of treated mice 24, 48 or 72 hours after oral administration of the test substance.