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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
1999/2000
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study according to GLP
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
2000

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
GLP compliance:
yes
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): genamin TA 100

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River S.p.A., Claco, Italy
- Age at study initiation: 9 weeks
- Weight at study initiation: 187 - 257 g
TEST ANIMALS
- Source: Charles River S.p.A., Italy
- Age at study initiation: approx. 9 weeks
- Weight at study initiation: 187 - 275 g
- Assigned to test groups randomly: yes
- Fasting period before study: no
- Housing: wire cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: yes

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2 °C
- Humidity (%): 55 +/- 10 %
- Air changes (per hr): 20
- Photoperiod (hrs dark / hrs light): 12 hours peridocally

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle used: sesame oil

Details on exposure:
- Administered volume: 10 mL/kg
Frequency of treatment:
single treatment
Doses / concentrations
Remarks:
Doses / Concentrations:
2000 mg/kg bw
Basis:
actual ingested
limit test
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle
Positive control(s):
Cyclophosphamide
- Route of administration: i.p.
- Doses / concentrations: 15 mg/kg

Examinations

Tissues and cell types examined:
bone marrow
Details of tissue and slide preparation:
DETAILS OF SLIDE PREPARATION:
2 slides/animal

ANALYSIS:
2000 polychromatic erythrocytes were scored for micronucleated cells. The ration of polychromatic to normochromatic erythrocytes (PCE/NCE) was calculated on 1 slide per animal by counting a total of 1000 PCEs.
Evaluation criteria:
Erythrocytes were classified as mature (normochromatic erythrocytes - NCE) or immature (polychromatic erythrocytes - PCE). The majority of micronuclei is circular, inside a PCE with normal morphology, where they are planar with the cytoplasm. A minority of micronuclei might be oval or almond-shaped, and a few are ring-shaped. Bodies with uncertain morphology or staining characteristics were not scored.

The test substance is considered to induce micronuclei if a statistically significant increase in micronucleus incidence (at p<0.05) is observed in any treatment group, in the pooled data for both sexes, or in the data for male or female groups alone. Where increases in the incidence of micronucleated PCEs were statistically significant but fell within the range of vehicle control values within the testing laboratory, concurrent and historical control data were used to evaluate the biological relevance of the findings.
Statistics:
Comparison of the micronucleus frequencies of the control group with the frequencies observed for the reference mutagen and treated with the test article was done using a non parametric method (Mann-Whitney).

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
yes
Remarks:
piloerection, hunched posture, hypoactivity, shallow breathing, one animal died about 48 h after treatment
Vehicle controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
Based on the study results, Genamin TA 100 is not mutagenic in the micronucleus test.
Executive summary:

A bone marrow micronucleus test (OECD TG 474) with tallow alkylamines (Genamin TA 100) in 50 Sprague Dawley rats (25 male and 25 female) led to a negative result after a single oral dose of 2000 mg/kg bw (Instituto di Ricerche Biomediche (2000c). The test substance was applicated in sesame oil by intragastric gavage. Sampling times were 24 h and 48 h after treatment. The tested dose induced clinical signs of toxicity (piloerection, hunched posture, hypoactivity and shallow breathing) in all animals. One male rat of the 48 h sampling time group died. For the mutagenicity evaluation 2000 polychromatic erythrocytes per animal were counted and scored for micronucleated cells. On the basis of the results obtained there was no significant difference between the micronucleus frequency in the treated groups in comparison with the negative control group, at any sampling time. The group of animals treated with Cyclophosphamide showed statistically significant frequency of micronucleated cells in comparison to the control group. Furthermore the ratio of polychromatic to normochromatic erythrocytes in both male and female animals remained unaffected by the tretament indicating that the test article is not toxic to bone marrow cells. Thus it is concluded that under the conditions of the present study Genamin TA 100 is not mutagenic in the micronucleus test.