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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
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
GLP compliance:
yes
Type of assay:
other: Mouse micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Test animals

Species:
mouse
Strain:
CD-1
Details on species / strain selection:
Crlj: CD1(ICR) strain
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: CRL Japan
- Age at study initiation: 7 weeks
- Weight at study initiation: 32.9 to 36.8 g (male DRF), 25.4 to 29.3 g (female DRF), 34 to 36.8 g (male micronucleus test).
- Assigned to test groups randomly: Yes
- Housing: Polycarbonate cages (group housed)
- Diet (e.g. ad libitum): Pelleted diet (adlib)
- Water (e.g. ad libitum): Provided adlib
- Acclimation period: At least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 50 +/- 20°C
- Air changes (per hr): > 10 changes per hour
- Photoperiod (hrs dark / hrs light): 12 h day (150 to 300 Lux)

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle(s)/solvent(s) used: Olive oil
- Justification for choice of solvent/vehicle: Substance insoluble in water and 0.5% carboxymethyl cellulose.
- Concentration of test material in vehicle: 10 mL/Kg

Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
The test substance 4000 mg and 1000 mg were weighed for the tests of dose determination and micronucleus assay respectively. These were added to a volume of olive oil and adjusted to 20 mL (DRF) or 5 mL (micronucleus test). The lower doses were serially diluted from the concentration. Test solutions were prepared before use.
Duration of treatment / exposure:
DRF: 24 or 48 hours
Micronucleus test: 24 hours
Frequency of treatment:
Administered once
Post exposure period:
24 or 48 hours (DRF) and 24 hours (micronucleus test)
Doses / concentrationsopen allclose all
Dose / conc.:
125 mg/kg bw/day (nominal)
Remarks:
DRF
Dose / conc.:
250 mg/kg bw/day (nominal)
Remarks:
DRF
Dose / conc.:
500 mg/kg bw/day (nominal)
Remarks:
DRF
Dose / conc.:
1 000 mg/kg bw/day (nominal)
Remarks:
DRF
Dose / conc.:
2 000 mg/kg bw/day (nominal)
Remarks:
DRF
Dose / conc.:
500 mg/kg bw/day (nominal)
Remarks:
Micronucleus assay
Dose / conc.:
1 000 mg/kg bw/day (nominal)
Remarks:
Micronucleus assay
Dose / conc.:
2 000 mg/kg bw/day (nominal)
Remarks:
Micronucleus assay
No. of animals per sex per dose:
2 males and 2 females per dose group in the DRF and 5 males per dose group in the micronucleus study.
Control animals:
yes, concurrent vehicle
Positive control(s):
Positive control: Mitomycin C (as prescribed in the test guideline)

Examinations

Tissues and cell types examined:
Bone marrow cells
Details of tissue and slide preparation:
The animals were sacrificed by cervical dislocation at 24 or 48 hours after dosing in the DRF and after 24 hours in the micronucleus test. The right femurs were dissected and bone marrow cells were treated and prepared on to glass slides using standard procedures. The slides were subsequently stained as appropriate.
Evaluation criteria:
Positive: The number of MNPCE increased dose-dependantly or significantly increased at a single dose point compared with negative controls.
Negative: Not meeting positive criteria.
Statistics:
The incidences of MNPCE and the ratio of PCE to RBC of each test substance concentration group and positive control group were compared with that of the negative control group for significant differences using Wilcoxon's rank sun test.

Results and discussion

Test results
Sex:
male
Genotoxicity:
negative
Toxicity:
yes
Vehicle controls validity:
valid
Negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
The induced frequency of the MNPCE in the positive control group was significantly higher with that of the negative control group. The PEC ratio to RBC did not differ compared with the negative control group. The results show that the study was conducted appropriately, and all values values were within relevant historical ranges.

Applicant's summary and conclusion

Conclusions:
The experimental findings conclude that the test substance was negative for mutagenicity as the substance did not increase the incidence of MNPCE in the mouse femoral bone marrow.