2,6,10-trimethylundec-9-enal

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

05 April 1993 - 08 April 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

The study was performed on a similar substance to the registered substance and as such is considered sufficient to address the endpoint by read-across.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: http://ntp.niehs.nih.gov/testing/types/genetic/invivo/mn/index.html

Version / remarks:

study was conducted according to National Toxicology Program protocols

Deviations:

no

GLP compliance:

not specified

Type of assay:

other: in vivo bone marrow mouse micronucleus

Test material

Test material information

Constituent 1

Reference substance name:

Citral

EC Number:

226-394-6

EC Name:

Citral

Cas Number:

5392-40-5

Molecular formula:

C10 H16 O

IUPAC Name:

3,7-dimethyl-2,6-octadienal

Test material form:

liquid

Specific details on test material used for the study:

Citral was obtained from Aldrich Chemical Company, Inc. (Milwaukee, WI) in two lots. Lot 06930PG was used during the 14-week studies, and lot 04402AQ was used during the 2-year studies.

Test animals

Species:

mouse

Strain:

B6C3F1

Sex:

male

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

corn oil

Details on exposure:

3 treatments of the chemical were administered at 24 hr. intervals over 72 hours

Duration of treatment / exposure:

72 hours

Frequency of treatment:

every 24 hours

Post exposure period:

none

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

250 mg/kg bw/day

Doses / concentrations 2

Dose / conc.:

500 mg/kg bw/day

Doses / concentrations 3

Dose / conc.:

750 mg/kg bw/day

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Positive control(s):

5 animals treated with 25 mg/kg Cyclophosphamide

Examinations

Tissues and cell types examined:

bone marrow derived polychromatic erythrocytes

Details of tissue and slide preparation:

bone marrow is flushed from the femurs and spread onto slides, which are air-dried, fixed, and stained with a fluorescent DNA-specific stain that easily illuminates any micronuclei that may be present

Evaluation criteria:

The acridine orange staining procedure that is used for micronucleus slides allows the scorer to differentiate between the recently formed, immature erythrocytes (polychromatic or PCE) that are less than 48 hrs old, and mature erythrocytes 2-35 days old (normochromatic or NCE) based on their staining characteristics. PCE contain residual RNA and thus they stain differently than the NCE that no longer have residual RNA. MN in PCEs arise from damage that occurred recently (within the past 48 hr).

Statistics:

A formal statistical analysis of the data is performed that includes a trend test, to determine if there is an overall increase across all doses in the frequency of cells containing micronuclei, and a pairwise comparison of each dose group to the corresponding control, to see if any one dose group is statistically different from the control group in frequency of micronucleated cells.

Results and discussion

Test results

Key result

Sex:

male

Genotoxicity:

negative

Toxicity:

yes

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Negative results were obtained in an in vivo bone marrow micronucleus test in male B6C3F1 mice treated by intraperitoneal injection with 250 to 750 mg/kg Citral daily for 3 days.

Executive summary:

Male B6C3F1 mice were exposed to 0, 250, 500 or 750 mg/kg citral in corn oil via intraperitoneal injection every 24 hours for 72 hours (i.e., total of three injections). Bone marrow was harvested 24 hours after the last dosing, flushed from femurs and spread onto slides. The slides were air-dried, fixed, and stained for scoring micronucleated cell frequency determination per animal. Citral was found not to increase the incidence of micronuclei in B6C3F1 male mice.