heptan-2-yl [(5-chloroquinolin-8-yl)oxy]acetate

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:

22 December 1986 to 03 September 1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Remarks:

a top dose level of 2500 mg/kg was used, 1000 PCE were examined per animal

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

heptan-2-yl [(5-chloroquinolin-8-yl)oxy]acetate

EC Number:

619-447-3

Cas Number:

99607-70-2

Molecular formula:

C18H22ClNO3

IUPAC Name:

heptan-2-yl [(5-chloroquinolin-8-yl)oxy]acetate

Details on test material:

- Name of test material (as cited in study report): CGA185072 tech.
- Purity: 91.6%
- Stability: confirmed

Test animals

Species:

hamster, Chinese

Strain:

other: random outbred strain

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 4-9 weeks (males), 6-10 weeks (females)
- Weight at study initiation: 22 to 34 g
- Assigned to test groups randomly: yes, by computer generated random numbers
- Housing: individual caging
- Diet: standard diet ad libitum
- Water: ad libitum
- Acclimation period: 4-5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 21°C
- Humidity: 52-66%
- Air changes: air conditioned room
- Photoperiod: 12 hrs dark / 12 hrs light

IN-LIFE DATES: From: 22 December 1986 To: 03 September 1987

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

0.5% CMC

Details on exposure:

Tolerability test: 2500 mg/kg bw, administered to 2 males + 2 females.
Main study: 625,1250, 2500 mg/kg bw (no mortality occurred in the toxicity test at 2500 mg/kg)
Control groups were treated with 0.5% CMC and the positive controls cyclophosphamide, 64 mg/kg bw.

The mutagenicity study was conducted in 8 male and 8 female hamsters per dose group and sampling time. In addition to the treated groups, negative and positive control groups were used. They received the vehicle (0.5% CMC) or the mutagen cyclophosphamide (CPA, 64 mg/kg).

Duration of treatment / exposure:

Single dose

Frequency of treatment:

Once

Post exposure period:

16, 24 or 48 hours

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

625 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

1 250 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

2 500 mg/kg bw/day (nominal)

No. of animals per sex per dose:

8 males and 8 females

Control animals:

yes, concurrent vehicle

Positive control(s):

- cyclophosphamide
- Route of administration: oral
- Doses / concentrations: 64 mg/kg bw

Examinations

Tissues and cell types examined:

Bone marrow smears were prepared from the shafts of both femurs. After staining, coded slides of 5 animals/sex/dose were scored. 1000 polychromatic erythrocytes per animal were scored for the incidence of micronuclei. The ratio of polychromatic to normochromatic erythrocytes was determined for each animal.

Details of tissue and slide preparation:

- Bone marrow smears were prepared from the shafts of both femurs.
- After staining, coded slides of 5 animals/sex/dose were scored.

Evaluation criteria:

The test substance is considered active if a statistically significant increase in the number of polychromatic erythrocytes with micronuclei in comparison with the negative control occurs at any dose and sampling time.

Statistics:

The significance of differences was assessed by the chi square test.

Results and discussion

Test results

Key result

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

- No mortality occurred
- Micronucleus test: There was no significant increase of micronuclei. The positive control substance yielded clearly enhanced incidences of polynucleated erythrocytes.

Any other information on results incl. tables

Table 1: Percentage of micronucleated PCE's at different preparation times

Compound and concentration	Sex	16 hours	24 hours	48 hours
Test article CGA185072 (625 mg/kg)	males females		0.04 0.10
Test article CGA185072 (1250 mg/kg)	males females		0.02 0.06
Test article CGA185072 (2500 mg/kg)	males females	0.06 0.08	0.04 0.12	0.04 0.16
Negative control Vehicle (0.5% CMC)	males females	0.06 0.08	0.02 0.08	0.06 0.04
Positive control Cyclophosphamide (64 mg/kg)	males females		4.54 4.22

 

Applicant's summary and conclusion

Conclusions:

negative

Executive summary:

The genotoxicity of cloquintocet-mexyl was studied under GLP to OECD TG 474 in an in vivo micronucleus assay using Chinese hamsters. Dose levels of 625, 1250 and 2500 mg/kg were orally administered. Animals were killed 16, 24 or 48 hours after dosing and bone marrow smears prepared from each femur. After staining the smears, slides from 5 animals/sex/dose were scored for 1000 polychromatic erythrocytes per animal. The number of micronuclei were assessed. Under the conditions of this test there were no clastogenic or aneugenic effects.