Santicizer 2148

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1990-02-06 to 1990-05-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

GLP compliance:

yes

Type of assay:

mammalian erythrocyte micronucleus test

Test material

Test material information

Constituent 1

Reference substance name:

Phenol

EC Number:

203-632-7

EC Name:

Phenol

Cas Number:

108-95-2

Molecular formula:

C6H6O

IUPAC Name:

phenol

Constituent 2

Reference substance name:

1-chlorododecane

Molecular formula:

C12H25Cl

IUPAC Name:

1-chlorododecane

Constituent 3

Reference substance name:

1-Dodecanol

Cas Number:

112-53-8

Molecular formula:

C12H26O

IUPAC Name:

1-Dodecanol

Constituent 4

Reference substance name:

1-Tetradecanol

Cas Number:

112-72-1

Molecular formula:

C14H30O

IUPAC Name:

1-Tetradecanol

Constituent 5

Reference substance name:

triphenyl phosphate

Cas Number:

115-86-6

Molecular formula:

C18H15O4P

IUPAC Name:

triphenyl phosphate

Constituent 6

Reference substance name:

-

EC Number:

431-760-5

EC Name:

-

Cas Number:

27460-02-2

Molecular formula:

C24H35O4P

IUPAC Name:

dodecyl diphenyl phosphate

Constituent 7

Reference substance name:

diphenyl tetradecyl phosphate

Cas Number:

142474-86-0

Molecular formula:

C26H39O4P

IUPAC Name:

diphenyl tetradecyl phosphate

Constituent 8

Reference substance name:

Didodecyl phenyl phosphate

Cas Number:

56827-93-1

Molecular formula:

C30H55O4P

IUPAC Name:

Didodecyl phenyl phosphate

Test material form:

liquid

Test animals

Species:

mouse

Strain:

CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

Male and female CD-1 mice. Upon receipt, the animals were quarantined for nine days. Only animals considered healthy by a staff veterinarian were released from quarantine and used for testing.
Prior to testing, the mice were uniquely identified using ear tags and corresponding cage cards.
The animals were housed two per cage prior to dosing and subsequently one per cage after dosing. The animals were housed in stainless steel cages with stainless steel mesh bottoms.
Water was provided ad libitum via an automatic watering system. Purina Certified Laboratory Rodent Chow No. 5002 was used as the diet and was nutritionally acceptable for the maintenance of laboratory rodents and has been certified by the manufacturer not to contain contaminants likely to interfere with the study.
The animals were housed in rooms designed to routinely maintain a 12-hour light cycle, a temperature between 64 and 79 °F, and humidity between 40 and 70%. There were no excursions in animal room environmental conditions which had any obvious impact on the results of the study.

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

Solutions of the test material were made using corn oil as the solvent on the day of treatment

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

500 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

2 500 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

5 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

15 mice / sex / dose (5 mice / sex for positive control)

Control animals:

not specified

Positive control(s):

Cyclophosphamide (60 mg/kg) was used as the positive control

Examinations

Tissues and cell types examined:

bone marrow cells

Details of tissue and slide preparation:

All animals were sacrificed by cervical dislocation and their femora were removed. Each bone was opened at the end and the bone marrow was flushed into approx. 2 ml of fetal bovine serum in a centrifuged tube. Bone marrow from both femora of each animal were pooled for slide preparation. The suspension was centrifuged to remove the serum. A portion of the remaining cells was placed on a clean glass microscope slide and a smear were prepared. Following preparation of the smears the slides were allowed to air dry overnight. The slides were stained using a Hema-Tek II slide staining machine and a Wright-Giemsa Stain Pak which includes stain, buffer and rinse solution.

Evaluation criteria:

Micronuclei were identified as uniform, darkly stained, round or oval shaped bodies found in the cytoplasm of polychromatic erythrocytes (PCEs). Bodies in PCEs which are refractile, improperly shaped or stained, or which were not in the focal plane of the cell were not scored as micronuclei. Cells containing more than one micronucleus were scored as a single micronucleated cell. The number of micronucleated PCEs per 1000 PCEs and the number of PCEs and normochromatic erythrocytes (NCEs) per 1000 erythrocytes was determined for each animal.

Statistics:

The individual test animal was used as the individual unit for analysis of micronucleated PCE frequency and PCE/erythrocyte fraction. Micronucleated PCE frequencies observed for each animal were transformed as the square root prior to analysis. PCR/total erythrocyte fractions were not transformed. A Dunnent’s test (one sided) was used for comparison of treatment group and positive control values which solvent control values. A significance level of p<0.05was used.

Results and discussion

Test results

Key result

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

not determinable

Any other information on results incl. tables

Summary of micronucleus assay results for XP-2563 mean body weight change and animal observations

Dosage (mg/kg)	Sex	Number treated	Mean body weight change (g)±sd			Deaths	Observations
			24 hours	48 hours	72 hours
Corn oil (control)	Male	15	-0.9±0.5	-1.0± 0.4	-0.5± 0.2	0	Normal
	Female	15	-0.8± 1.1	-1.4± 0.6	-0.6± 0.9	0	Normal
500	Male	15	-3.3± 4.2	-1.9± 0.5	-1.7± 0.7	0	Normal
	Female	15	-0.7± 1.0	-1.6± 0.8	-1.4± 0.6	0	Normal
2500	Male	15	-2.2± 0.3 **	-2.1± 0.7 *	-2.0± 0.6 **	0	Normal
	Female	15	-2.0± 0.6 **	-2.0± 1.0	2.3± 0.9 *	0	Normal
5000	Male	15	-2.1± 1.2	-2.9± 1.1 **	3.3± 1.8 **	0	Normal
	Female	15	-1.3± 0.8	-3.6± 0.7 **	2.2± 1.3	1	Normal
Cyclo-phosphamide (60 mg/kg) (positive control)	Male	5	-0.9± 0.4	~± ~	~± ~	0	Normal
	Female	5	0.2± 0.3	~± ~	~± ~	0	Normal

 

* p≤0.05; ** p≤0.01 by one sided t-test

 

 

 

Summary of micronucleated assay results for XP-2563 PCE ratio and micronucleus data for low dose animals (dosage 500 mg/kg)

Harvest time (hr)	Sex	Number	Mean PCE/ total erythrocyte fraction± sd			Mean micronucleated PCE/1000 PCE± sd
			Vehicle control	Test material	Positive control	Vehicle control	Test material	Positive control
24	Male	5	0.54± 0.07	0.48± 0.05	0.50± 0.05	0.2± 0.45	0.2± 0.45	21.2± 18
	Female	5	0.55± 0.04	0.53± 0.04	0.52± 0.05	0.4± 0.55	0.6± 0.89	35.6± 12
48	Male	5	0.51± 0.08	0.48± 0.07	~± ~	1.2± 1.79	1.6± 1.34	~± ~
	Female	5	0.56± 0.05	0.56± 0.05	~± ~	1.0± 0.71	0.8± 0.84	~± ~
72	Male	5	0.57± 0.08	0.44± 0.07 *	~± ~	1.6± 2.61	1.0± 1.41	~± ~
	Female	5	0.60± 0.07	0.57± 0.05	~± ~	1.4± 1.14	0.6± 0.89	~± ~

* p≤0.05; ** p≤0.01 by one sided t-test. square root transformed data used for statistical analysis of micronucleated PCE

 

Summary of micronucleated assay results for XP-2563 PCE ratio and micronucleus data for middle dose animals (dosage 2500 mg/kg)

Harvest time (hr)	Sex	Number	Mean PCE/ total erythrocyte fraction± sd			Mean micronucleated PCE/1000 PCE± sd
			Vehicle control	Test material	Positive control	Vehicle control	Test material	Positive control
24	Male	5	0.54± 0.07	0.47± 0.06	0.50± 0.05	0.2± 0.45	3.0± 3.54	21.2± 18.0
	Female	5	0.55± 0.04	0.55± 0.06	0.52± 0.05	0.4± 0.55	0.6± 0.89	35.6± 12.0
48	Male	5	0.51± 0.08	0.53± 0.09	~± ~	1.2± 1.79	1.2± 0.84	~± ~
	Female	5	0.56± 0.05	0.50± 0.07	~± ~	1.0± 0.71	1.0± 0.71	~± ~
72	Male	5	0.57± 0.08	0.57± 0.08	~± ~	1.6± 2.61	0.2± 0.45	~± ~
	Female	5	0.60± 0.07	0.51± 0.06 *	~± ~	1.4± 1.14	0.6± 0.89	~± ~

* p≤0.05; ** p≤0.01 by one sided t-test. square root transformed data used for statistical analysis of micronucleated PCE

 

Summary of micronucleated assay results for XP-2563 PCE ratio and micronucleus data for high dose animals (dosage 5000 mg/kg)

Harvest time (hr)	Sex	Number	Mean PCE/ total erythrocyte fraction± sd			Mean micronucleated PCE/1000 PCE± sd
			Vehicle control	Test material	Positive control	Vehicle control	Test material	Positive control
24	Male	5	0.54± 0.07	0.45± 0.09	0.50± 0.05	0.2± 0.45	0.4± 0.55	21.2± 18.0
	Female	5	0.55± 0.04	0.49± 0.04 *	0.52± 0.05	0.4± 0.55	0.6± 0.89	35.6± 17.0
48	Male	5	0.51± 0.08	0.49± 0.04	~± ~	1.2± 1.79	1.0± 1.41	~± ~
	Female	5	0.56± 0.05	0.44± 0.03 **	~± ~	1.0± 0.71	0.6± 0.89	~± ~
72	Male	5	0.57± 0.08	0.48± 0.07 *	~± ~	1.6± 2.61	0.4± 0.55	~± ~
	Female	5	0.60± 0.07	0.41± 0.06 **	~± ~	1.4± 1.14	1.2± 1.79	~± ~

* p≤0.05; ** p≤0.01 by one sided t-test. square root transformed data used for statistical analysis of micronucleated PCE

Applicant's summary and conclusion

Conclusions:

Based on the observations and findings, it is concluded that XP-2563 is not a mammalian genotoxicant in vivo in mouse bone marrow cells under the experimental conditions of the study.

Executive summary:

The potential for XP-2563 to induce chromosomal effects was tested in a mouse bone marrow micronucleus assay. XP-2563 administrated by intraperitoneal injection to groups of male and female CD-1 mice at doses of 500, 2500 or 5000 mg/kg bw. Following the dose, the mouse bone marrow was sampled at 24, 48 and 72 hours. In the micronucleus experiment, one death was observed in the female mice treated with 5000 mg/kg of XP-2563. Indicated by a statistically significant decrease mean body weight and statistically significant decreases in the PCE/total erythrocyte ratio observed in the XP-2563 treated animals. XP-2563 did not induce statistically significant increases in micronucleated PCEs in any of the treated animals. Increases in micronucleated PCE frequency were observed in the positive control group demonstrating the adequacy of the experimental conditions.

Based on the observations and findings, it is concluded that XP-2563 is not a mammalian genotoxicant in vivo in mouse bone marrow cells under the experimental conditions of the study.