3,7,11,15-tetramethylhexadec-1-en-3-ol

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:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Peer-reviewed data, available as short summary from secondary source, reliability according to HPV/ICCA SIDS.

Data source

Reference

Reference Type:

secondary source

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Version / remarks:

Limit test

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

3,7,11,15-tetramethylhexadec-1-en-3-ol

EC Number:

208-008-8

EC Name:

3,7,11,15-tetramethylhexadec-1-en-3-ol

Cas Number:

505-32-8

Molecular formula:

C20H40O

IUPAC Name:

3,7,11,15-tetramethylhexadec-1-en-3-ol

Details on test material:

- Name of test material (as cited in study report): Isophytol
- Physical state: not reported
- Analytical purity: 97.5 % (weight, GC) respective 98.0 % (area, GC)
- Impurities (identity and concentrations): no data
- Purity test date: 23 Jan 2002
- Lot/batch No.: UU02013601
- Other: Source: Teranol AG, Lalden, Switzerland

Test animals

Species:

mouse

Strain:

NMRI

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Sulzfeld, Germany
- Age at study initiation: 6-8 weeks
- Weight at study initiation: not reported
- Assigned to test groups randomly: yes, under following basis: no data
- Fasting period before study: 3-4 hours prior to dosing
- Housing: 5/cage
- Diet: pelleted diet (Altromin, code VRF 1, Lage, Germany); ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21±3
- Humidity (%): 30 to over 70; despite the relative humidity partly exceeding 70 %, no abnormalities were noted in the animals. The deviation was concluded not to affect the integrity of the study.
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: corn oil
- Concentration of test material in vehicle: 200mg/ml
- Amount of vehicle (if gavage or dermal): 10 ml/kg bw

Duration of treatment / exposure:

not applicable

Frequency of treatment:

once

Post exposure period:

24 and 48 hours

Doses / concentrations

Remarks:

Doses / Concentrations:
2000 mg/kg bw
Basis:
nominal conc.

No. of animals per sex per dose:

5 males (3 males and 3 females in range-finding study)

Control animals:

yes, concurrent vehicle

Positive control(s):

cyclophosphamide
- Route of administration: not reported
- Doses / concentrations: 50 mg/kg bw

Examinations

Tissues and cell types examined:

bone marrow erythrocytes

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION: Range-finder study: 3 males and 3 females dosed with 2000 mg/kg bw showed no abnormalities during an observation period of 3 days.

TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields): Application by oral gavage, animals of the 2 treated groups were sacrificed 24 and 48 hours, respectively, after dosing. The control groups were sacrificed 24 hours after treatment.

DETAILS OF SLIDE PREPARATION: Both femurs of each animal were removed, freed of blood and muscles, and both ends of the bone were cut open. The bone marrow was flushed out with fetal calf serum (FCS). The suspension was centrifuged and the cells resuspended in FCS. A drop of the suspension was placed on the end of a previously cleaned and marked microscopic slide, spread using a clean slide and air-dried, fixed with 100 % methanol, automatically stained in HEMA-tek Slide Stainer (Miles, Bayer Nederland, The Netherlands) and covered with a glass coverslip.

METHOD OF ANALYSIS: Before analysis, the slides were randomised by labelling with codes. They were first screened at a magnification of x100 for suitable regions, then scored at x1000. The number of micronucleated polychromatic erythrocytes was counted in a total of 2000 polychromatic erythrocytes per slide. The ratio of polychromatic to normochromatic erythrocytes was determined in the first 1000 erythrocytes scanned. Micronuclei were only counted in polychromatic erythrocytes.

Evaluation criteria:

The test was considered acceptable if the positive control substance induced a significant increase in micronucleated polychromatic erythrocytes and the incidence of micronucleated polychromatic erythrocytes was reasonably within the laboratory historical controls range (mean ± 3 SD).

Statistics:

Averages and standard deviations for the four groups were calculated. Positive: induction of a statistically significant (Wilcoxon Rank sum test, two-sided test at p<0.05) increase in the frequency of micronucleated polychromatic erythrocytes, at any dose or sampling time. Negative: no such statistically significant increase.

Results and discussion

Test results

Sex:

male

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: 2000 mg/kg bw
- Clinical signs of toxicity in test animals: none

RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): none
- Ratio of PCE/NCE (for Micronucleus assay): yes: see table
- Appropriateness of dose levels and route: yes
- Statistical evaluation: yes

Any other information on results incl. tables

As there were no obvoius differences between the sexes, it was decided to use only males in the main test. The mean body weights of all 4 groups, recorded just before dosing, were not statistically different. All animals treated with 2000 mg/kg bw showed no abnormalities; this was also true for both the negative and the positive controls.

Average numbers of micronucleated polychromatic erythrocytes and ratios of polychromatic to normochromatic erythrocytes:

Group	Dose (mg/kg bw)	Sampling time (h)	Number (mean±SD)	Ratio (mean±SD)
Vehicle	0	24	0.6 ± 0.9	1.15 ± 0.20
Isophytol	2000	24	0.2 ± 0.4	1.09 ± 0.11
Isophytol	2000	48	0.4 ± 0.9	1.17 ± 0.10
Cyclophosphamide	50	24	25.8 ± 5.5 **	0.39 ± 0.06

** Significantly different from vehicle control group, p <= 0.01