Dibutyl maleate

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test was performed according to OECD guideline 474 under GLP conditions.

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Dibutyl maleate

EC Number:

203-328-4

EC Name:

Dibutyl maleate

Cas Number:

105-76-0

Molecular formula:

C12H20O4

IUPAC Name:

dibutyl but-2-enedioate

Details on test material:

Purity: 98 - 99%
Dibutylmaleinat, dibutylmaleate
Appearance: clear liquid
Batch: 215 71 35

Test animals

Species:

mouse

Strain:

NMRI

Sex:

male/female

Details on test animals or test system and environmental conditions:

Supplier: Charles River WIGA GmbH
Numebr: 25 male and 25 female
Age: approximately 10 weeks at time of application

The test substance was administered via gavage once to 3 groups of of 5 male and 5 female NMRI mice per group.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

distilled water

Details on exposure:

Negative control: Dimethylsulfoxide (DMSO, E. Merck, D-6100 Darmstadt, No. 2931 p.a. dried, with max. 0.03% water) at a dose volume of 5 ml/kg bw.
Test material: 2000 mg

Frequency of treatment:

Once

Post exposure period:

Animals were sacrificed 24, 48 and 72 hous p.a.

Doses / concentrations

Remarks:

Doses / Concentrations:
2000 mg/kg BW
Basis:
no data

No. of animals per sex per dose:

5 per sex per dose

Positive control(s):

A single dose of 40 mg/kg of cyclophosphamide (Serva No 17681) 24 hours before sacrificed was used as positive control. Cyclophosphamide was dissolved in distilled water at a dose volume of 10 ml/kg bw.

Examinations

Tissues and cell types examined:

Bone marrow and peripheral blood cells

Evaluation criteria:

Number of micronucleated erythrocytes

Statistics:

P= 0.05 was selected for each test.
H-test of Kruskal and Wallis followed by the test of Nemeyi: differences between the dose groups and the negative control group.
U-test of Wilcoxon, Mann and Whitney: differences between the negative and the positive control groups and between the sexes within each group.
Composition of bone marrow, body weight: 1) analysis of variance followed by the Scheffe-test: comparison of more than two groups. 2) t-test: comparison of only two groups.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Remarks:

There was no significant defference in the amount of nucleated cells, amount of polychromatic erythrocytes and rate of micronucleated normochromatic erythrocytes between the dosed groups and the negative control group. Increased micronuclei rates were o

Toxicity:

yes

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

The test compound did not change the ratio of polychromatic erythrocytes to all erythrocytes. At all 3 time points slight increases in the number of micronucleated erythrocytes were obtained which were, however, not statistically significant. The results at 24 and 48 hours were also slightly in excess of the upper limits of historical control data. Positive control gave the expected response showing reliability in the system.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative
Under the conditions of this study, dibutyl maleate was not mutagenic in the mcironucleus in vivo test at 2000 mg/kg, but a slight clastogenic effect could not be excluded.

Executive summary:

A micronucleous in vivo test was performed according to OECD guideline 474. Based on a range finding study, a dose of 2000 mg dibutyl maleate per kg bw were administered once by gavage to 3 groups of 5 male and 5 female NMRI mice per group. Animals were killed 24, 48 and 72 hours post administration of the test substance. For the positive control, a single dose of 40 mg/kg cyclophosphamide was administered 24 hours before sacrifice and increased number of micronucleated erythrocytes was observed. The test compound did not change the ratio of polychromatic erythrocytes to all erythrocytes. At all 3 time of evaluation, no statistically significant increase in the number of micronucleated erythrocytes were obtained. Based on these conditions, it was concluded that dibutyl maleate is not mutagenic in the micronucleus in vivo study at the dose of 2000mg/kg, but a slight clastogenic effect could not be excluded without further evaluation.