Ethylenebis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate]

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Remarks:

1000 instead of 2000 cells scored per animal

GLP compliance:

no

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Ethylenebis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate]

EC Number:

253-039-2

EC Name:

Ethylenebis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate]

Cas Number:

36443-68-2

Molecular formula:

C34H50O8

IUPAC Name:

ethane-1,2-diylbis(oxyethane-2,1-diyl) bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propanoate]

Test animals

Species:

hamster, Chinese

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: Females weighed 21-28 g and males weighed 21-30 g.
- Housing: Individual caging.
- Diet (e.g. ad libitum): Standard diet (NAFAG No.924) ad libitum.
- Water (e.g. ad libitum): Ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22-23 °C.
- Humidity (%): 54-57%.
- Photoperiod (hrs dark / hrs light): 12 h/12 h.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: CMC (carboxymethyl cellulose) plus Tween 80.
- Amount of vehicle (if gavage or dermal): 20 mL CMC plus Tween 80/kg body weight.
- Vehicle(s)/solvent(s) used: Sodium CMC (carboxymethyl cellulose) plus Tween 80.
- Concentration of test material in vehicle: 750, 1,500, and 3,000 mg/kg body weight in 20 mL/kg body weight of 0.5% aqueous solution of sodium CMC containing 0.1% Tween 80.

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: No details.

Duration of treatment / exposure:

The preparation was administered orally to groups of 6 female and 6 male animals each. Treatment consisted of daily one gavage administration on 2 consecutive days.

Frequency of treatment:

Once/day.

Post exposure period:

24 h after the second application, the animals were sacrificed by dislocation of the cervical vertebrae.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

750 mg/kg bw/day (actual dose received)

Doses / concentrations 2

Dose / conc.:

1 500 mg/kg bw/day (actual dose received)

Doses / concentrations 3

Dose / conc.:

3 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

6 Males and 6 females.

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamide
- Route of administration: Oral (gavage).
- Doses/concentrations: 128 mg/kg body weight in 20 mL/kg body weight.

Examinations

Tissues and cell types examined:

Bone marrow was harvested from the shafts of both femurs.

Details of tissue and slide preparation:

DETAILS OF SLIDE PREPARATION:
In a siliconized pipette filled with approx. 0.5 µL rat serum the bone marrow was drawn up. In order to receive a homogeneous suspension the content of pipette was aspirated gently about 3 times. Small drops of the mixture were transferred on the end of a slide, spread out by pulling it behind a polished cover glass and the preparations were air-dried. 3 Hours later, the slides were stained in undiluted May-Grünwald solution for 2 minutes then in May-Grünwald solution:water 1:1 for 2 minutes and then in Giemsa's (40%) for 20 minutes. After being rinsed in methanol (55%) for 5-8 seconds and washed off twice in water, they were left immersed in water for approximately 2 minutes. After rinsing with distilled water and air-drying, the slides were cleared in Xylol and mounted in Eukitt.

Evaluation criteria:

The slides of 3 female and 3 male animals each of the negative control group, the positive control group and of the groups treated with various dose were examined. 1000 Bone marrow cells each were scored per animal and the following anomalies were registered:
a) Single Jolly bodies;
b) fragments of nuclei in erythrocytes;
c) micronuclei in erythroblasts;
d) micronuclei in leucopoietic cells; and
e) polyploid cells.

Statistics:

The significance of difference was assessed by chi-square test.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

In all dosage groups the percentage of cells displaying anomalies of nuclei did not differ significantly from the negative control. By contrast, the positive control (cyclophosphamide, 128 mg/kg body weight) yielded a marked increase of the percentage of cells with anomalies. Here the mean percentage of anomalies was 9.68, whereas the negative control yielded a percentage of 0.10. The difference is highly significant (p<0.05).

Any other information on results incl. tables

EXPERIMENTAL RESULTS

			percent of cells with anomalies of nuclei
	number of animal	sex of animal	single jolly bodies	frasgments of nuclei in erythrocytes	micronuclei in erythroblasts	micronuclei in leucopoietic cells	polyploid cells	total
Control (0.5% CMC + 0.1% Tween 80)	1	f				0.1		0.1
	2	f					0.1	0.1
	3	f	0.2			0.1		0.3
	4	m						0.0
	5	m						0.0
	6	m	0.1					0.1
Cyclophosphamide (128 mg/kg)	1	f	5.5	0.9	2.1	0.6		9.1
	2	f	10.9	1.7	1.7	0.4		14.7
	3	f	6.0	0.2	2.4	0.1	0.1	8.8
	4	m	5.1	0.6	0.8	0.2		6.7
	5	m	5.7	1.6	1.4	0.3	0.1	9.1
	6	m	8.2	0.9	0.2	0.4		9.7
test article (750 mg/kg)	1	f						0.0
	2	f	0.2					0.2
	3	f	0.2					0.2
	4	m	0.2					0.2
	5	m						0.0
	6	m						0.0
test article (1500 mg/kg)	1	f	0.1					0.1
	2	f	0.1					0.1
	3	f	0.1					0.1
	4	m	0.1					0.1
	5	m						0.0
	6	m	0.1					0.1
test article (3000 mg/kg)	1	f	0.1					0.1
	2	f	0.2		0.1	0.1		0.4
	3	f	0.1			0.1		0.2
	4	m						0.0
	5	m						0.0
	6	m	0.1					0.1

Applicant's summary and conclusion

Conclusions:

It was concluded that, under the conditions of this experiment, no evidence of mutagenic effects were noted in Chinese hamsters treated with the test substance.