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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
Study period:
2007-02-05 to 2007-03-20
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
It is a GLP compliant study conducted in compliance with agreed protocols, with no or minor deviations for the standard test.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Version / remarks:
Historical control data were updated; Age of the animals was 7 wks at start of experiment; neither of these affected the validity of the study.
Deviations:
yes
Remarks:
Historical control data were updated; Age of the animals was 7 wks at start of experiment; neither of these affected the validity of the study.
Qualifier:
according to
Guideline:
EU Method B.12 (Mutagenicity - In Vivo Mammalian Erythrocyte Micronucleus Test)
Deviations:
yes
Remarks:
Historical control data were updated; Age of the animals was 7 wks at start of experiment; neither of these affected the validity of the study.
GLP compliance:
yes (incl. certificate)
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 10-undecanal (code 52890)
- Molecular formula: C₁₁H₂₀O
- Molecular weight: 453.109
- Smiles notation: C=CCCCCCCCCC=O
- InChl: InChI=1S/C11H20O/c1-2-3-4-5-6-7-8-9-10-11-12/h2,11H,1,3-10H2
- Structural formula attached as image file (if other than submission substance): see Illustration (picture/graph) below.
- Substance type: White to slight yellow liquid
- Physical state: Liquid
- Analytical purity: 97.7 %
- Impurities (identity and concentrations): No data
- Composition of test material, percentage of components: No data
- Isomers composition: No data
- Purity test date: 2007-06-06
- Batch No: 7500118249
- Expiration date of the batch: 2007-11-10
- Stability under test conditions: No data
- Storage condition of test material: In the refrigerator at 2 °C to 8 °C.
- Details of analysis are given in the attached supporting information.

Test animals

Species:
mouse
Strain:
NMRI
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Winkelmann GmbH, D-33178 Borchen, Germany
- Age at study initiation: 7 wks
- Weight at study initiation: Males mean 36.7 g (SD 1.8 g), females mean 28.2 g (SD 2.0 g)
- Assigned to test groups randomly
- Fasting period before study:
- Housing: Conventionally under standard laboratory conditions; Makrolon Type I cage with wire mesh top, granulated soft wood bedding
- Diet: Pelleted standard diet ad libitum
- Water: Tap water ad libitum
- Acclimation period: ≥ 5 d

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: 30 % to 70 %
- Air changes (per hr): No data
- Photoperiod: 12 hrs dark / 12 hrs light

Administration / exposure

Route of administration:
oral: unspecified
Vehicle:
- Vehicle(s)/solvent(s) used: Corn oil
- Justification for choice of solvent/vehicle: Chosen for its relative non-toxicity to animals.
- Volume of vehicle: 10 mL/kg bw
Duration of treatment / exposure:
Single exposure
Frequency of treatment:
Single exposure
Post exposure period:
24 hrs (all dose levels) and 48 hrs (highest dose level only, i.e. 2000 mg/kg bw )
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
500 mg/kg bw
Basis:
actual ingested
Remarks:
Doses / Concentrations:
1000 mg/kg bw
Basis:
actual ingested
Remarks:
Doses / Concentrations:
2000 mg/kg bw
Basis:
actual ingested
No. of animals per sex per dose:
6 males, 6 females, tested per dose group and sampling time.
5 males, 5 females, evaluated per dose group and sampling time.
Control animals:
yes, concurrent vehicle
yes, historical
Positive control(s):
- Positive control substance: Cyclophosphamide (CPA), dissolved in ionised water.
- Justification for choice of positive control: The stability of CPA at room temperature is sufficient. At 25 °C only 3.5 % of its potency is lost after 24 hrs.
- Route of administration: Orally, once
- Dose: 40 mg/kg bw
- Concentration: 10 mL/kg bw

Examinations

Tissues and cell types examined:
Bone marrow
Details of tissue and slide preparation:
DETAILS OF SLIDE PREPARATION:
- The animals were sacrificed using CO₂ followed by bleeding.
- The femora were removed, the epiphyses were cut off and the marrow was flushed out with foetal calf serum using a syringe.
- The cell suspension was centrifuged at 1500 rpm (390 × g) for 10 mins and the supernatant was discarded.
- A small drop of resuspended cell pellet was spread on a slide. The smear was air dried and then smeared with May-Grünwald/Giemsa (both Merck, D-64293, Darmstadt, Germany).
- Cover slips were mounted with EUKITT (Kindler, D-79110, Freiburg, Germany).
- ≥ 1 slide was made from each bone marrow sample.

METHOD OF ANALYSIS:
- Evaluation of the cells was performed using Nikon microscopes with 100 × oil immersion objectives.
- ≥ 2000 polychromatic erythrocytes (PCEs) were analysed per animal for micronuclei.
- To describe a cytotoxic effect the ratio between polychromatic and normochromatic endpoints was determined in the same sample and expressed in PCEs per 2000 erythrocytes.
- The analysis was performed with coded slides.
Evaluation criteria:
A test item would have been classified as mutagenic if it induced either a dose-related increase or a clear increase in the number of micronucleated polychromatic erythrocytes in a single dose group. Statistical methods were used as an aid to evaluation of the results. However, the primary point of consideration was the biological relevance of the results. A test item that failed to produce a biologically relevant increase in the number of micronucleated polychromatic erythrocytes would have been considered non-mutagenic in this system.
Statistics:
Statistical significance at the 5 % level was evaluated by means of the non-parametric Mann-Whitney test.

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- Clinical signs of toxicity in test animals: No effects at 100 mg/kg bw or 1000 mg/kg bw. Ruffled fur in all 4 animals tested at 2000 mg/kg at 1-6 hr after treatment, but no effect at 24 hrs to 48 hrs after treatment.

RESULTS OF DEFINITIVE STUDY
- Clinical signs of toxicity: None, at all concentrations.
- For results summary see tables under "Any other information on results incl. tables" below.
- For full results please refer to the attached supporting information.
- Compared to vehicle controls there was no statistically significant or biologically relevant increase in the frequency of detected micronuclei at any preparation interval or dose level after administration of the test item. The mean values of micronuclei observed after treatment with the test material were below or near to the vehicle control group.
- Positive control showed a statistically significant increase in induced micronucleus frequency.

Any other information on results incl. tables

Summary of micronucleus test results

Test group Dose mg/kg bw Sampling time (hr) PCEs with micronuclei (%) Range PCE per 2000 erythrocytes 
Vehicle 0 24 0.105 0-5  1129
Test item 500 24 0.135 1-5 962
Test item 1000 24 0.160 1-6 1001
Test item 2000 24 0.110 0-4 1032
Positive control 40 24 2.700 40-79 1098
Test item 2000 48 0.100 0-5 1120

Historical control data

  Vehicle controls Positive controls (CPA)
Males Females Total Males Females Total
Mean*, SD 0.086 ± 0.04 0.066 ± 0.036 0.077 ± 0.031 2.118 ± 0.71 1.568 ± 0.615 1.868 ± 0.618
Range** 0.01-0.23 0.00-0.19 0.01-0.16 0.70-4.19 0.49-3.68 0.77-3.68
No. of experiments 276 256 277 276 256 277

* Mean value (% micronucleated cells)

** Range of mean group values (% micronucleated cells)

Biometry

Vehicle control versus test group Significance p value
500 mg/kg bw test material at 24 hr - 0.2223
1000 mg/kg bw test material at 24 hr - 0.0784
2000 mg/kg bw test material at 24 hr - 0.5000
40 mg/kg bw positive control at 24 hr + < 0.0001
2000 mg/kg bw test material at 48 hr n.t. -

n.t. = Not tested, as the mean micronucleus frequency was not above the vehicle control value.

Applicant's summary and conclusion

Conclusions:
The test substance was assessed for genotoxicity in vivo in a mouse micronucleus assay according to OECD guideline 474. Under the conditions of the test, undec-10-enal was found to be negative for genetic toxicity.