Registration Dossier

Diss Factsheets

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Link to relevant study records
Reference
Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
13 September 2006 - 3 November 2006
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay
Target gene:
Histidine gene
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 102
Metabolic activation:
with and without
Metabolic activation system:
phenobarbitone/β-naphthoflavone (80/100 mg per kg per day) induced rat liver S9 mix
Test concentrations with justification for top dose:
Preliminary test: 0, 0.15, 0.5, 1.5, 5, 15, 50, 150, 500, 1500 and 5000 μg/plate
First mutation test: 50, 150, 500, 1500 and 5000 μg/plate
Second mutation test: 50, 150, 500, 1500 and 5000 μg/plate
Vehicle / solvent:
- Solvent used: sterile distilled water
- Justification for choice of solvent/vehicle: The test material was soluble in sterile distilled water at 50 mg/ml in solubility checks performed in-house.
Negative solvent / vehicle controls:
yes
Remarks:
without S9
Positive controls:
yes
Remarks:
without S9
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Remarks:
3 μg/plate for TA100 and 5 μg/plate for TA1535
Positive controls:
yes
Remarks:
without S9
Positive control substance:
9-aminoacridine
Remarks:
80 μg/plate for TA1537
Positive controls:
yes
Remarks:
without S9
Positive control substance:
mitomycin C
Remarks:
0.5 μg/plate for TA102
Positive controls:
yes
Remarks:
without S9
Positive control substance:
4-nitroquinoline-N-oxide
Remarks:
0.2 μg/plate for TA98
Positive controls:
yes
Remarks:
with S9
Positive control substance:
other: 2-aminoanthracene
Remarks:
1 μg/plate for TA100 and 2 μg/plate for TA1535 and TA1537
Positive controls:
yes
Remarks:
with S9
Positive control substance:
benzo(a)pyrene
Remarks:
5 μg/plate for TA98
Positive controls:
yes
Remarks:
with S9
Positive control substance:
other: 1,8-dihydroxyanthraquinone
Remarks:
10 μg/plate for TA102
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: in triplicate against each tester strain

DETERMINATION OF CYTOTOXICITY
- Method: numbers of revertant colonies and growth of the bacterial background lawn
Evaluation criteria:
There are several criteria for determining a positive result, such as a dose-related increase in revertant frequency over the dose range tested and/or a reproducible increase at one or more concentrations in at least one bacterial strain with or without metabolic activation. Biological relevance of the results will be considered first, statistical methods can also be used as an aid to evaluation, however, statistical significance will not be the only determining factor for a positive response. A test material will be considered non-mutagenic (negative) in the test system if the above criteria are not met.
Key result
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
RANGE-FINDING/SCREENING STUDIES:
The test material was non-toxic to the strain of Salmonella used (TA100).

COMPARISON WITH HISTORICAL CONTROL DATA:
All of the positive control chemicals used in the test induced marked increases in the frequency of revertant colonies thus confirming the activity of the S9-mix and the sensitivity of the bacterial strains.

The test material caused no visible reduction in the growth of the bacterial background lawn at any dose level. The test material was, therefore, tested up to the maximum recommended dose level of 5000 μg/plate. No test material precipitate was observed on the plates at any of the doses tested in either the presence or absence of S9-mix. No toxicologically significant increases in the frequency of revertant colonies were recorded for any of the strains of Salmonella, at any dose level either with or without metabolic activation. A small, statistically significant increase (P≤0.05) in revertant colony frequency was observed in tester strain TA1535 (without S9) at 5000 μg/plate in Experiment 1 only. This increase was within the spontaneous mutation range and the historical range expected for this strain, was non-reproducible and exhibited no dose response relationship. Therefore, the increase was considered to be of no toxicological relevance.

Conclusions:
An in vitro gene mutation study (AMES study) was conducted according to OECD/EC guidance and GLP principles. The test substance was found to be non-mutagenic under the conditions of this test.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Link to relevant study records
Reference
Endpoint:
in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2001
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail
Qualifier:
according to guideline
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
GLP compliance:
yes (incl. QA statement)
Type of assay:
mammalian bone marrow chromosome aberration test
Species:
rat
Strain:
Wistar
Details on species / strain selection:
HsdOla:WI
Sex:
male/female
Route of administration:
oral: gavage
Vehicle:
The vehicle control material used was 1% w/v aqueous methylcellulose (400 cps)
Details on exposure:
Because of the short half-life, the animals were doced twice a day (2 equal sub-doses given 6 h apart)
Duration of treatment / exposure:
2 consecitive days
Frequency of treatment:
twice a day (2 equal sub-doses given 6 h apart) for 2 consecitive days
Post exposure period:
48 h bone marrow sampling
Dose / conc.:
500 mg/kg bw/day
Dose / conc.:
1 000 mg/kg bw/day
Dose / conc.:
2 000 mg/kg bw/day
No. of animals per sex per dose:
standard 5 males and 5 females
Control animals:
yes, concurrent vehicle
Positive control(s):
control material used was 1% w/v aqueous methylcellulose
Key result
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Conclusions:
It was concluded that ucb 34714 did not induce micronuclei in bone marrow cells when tested, in male and female Wistar rats, to the maximum tolerated oral dose of 2000 mg.kg-l day-l given as 2 equal daily sub-doses 6 h apart for 2 consecutive days.
Executive summary:

he in vivo genotoxic potential of ucb 34714 was evaluated in a micronucleus test in bone marrow erythrocytes of young, male and female Wistar rats. The animals were dosed twice daily (2 equal sub-doses given 6 h apart) for 2 consecutive days (ie 4 consecutive doses at O, 6, 24 and 30 h). The dosing regimen was based on Sponsor information that the test material has a short half-life in rats. The rats were dosed orally by gavage.

A toxicity study was undertaken to establish a suitable dose range for the micronucleus experiment. Based on the findings of the toxicity study, the maximum tolerated dose of ucb 34714 was judged to be in the region of 2000 mg.kg-l.day-l.

In the micronucleus test, male rats were dosed with the test item at concentrations equivalent to 500, 1000 and 2000 mg.kg-l.day-l. Female rats were dosed with the test item at 2000 mg.kg-’ day-l. Bone marrow samples were taken 48 h after the initial dose. Two control groups of Wistar rats were dosed orally with either the vehicle, (1YOw/v aqueous methyl cellulose), (males and females) or the positive control agent, (50 mg cyclophosphamide. kg-i. day-l (males only). The experimental schedule for the control groups followed that of the test item treated rats. Each group consisted of 5 rats per sex where applicable. An additional 5 animals/sex were dosed with the test item at 2000 mg.kg-l day-l, and served as a contingency in case of unscheduled deaths. Blood samples for toxicokinetic analysis were taken 1.5 h after the last dose.

No micronucleus induction was detected in bone marrow erythrocytes of rats dosed with ucb 34714.

Animals treated with the vehicle alone showed normal background levels of micronuclei, while animals dosed with cyclophosphamide responded with substantial increases in the numbers of bone marrow micronuclei.

It was concluded that ucb 34714 did not induce micronuclei in bone marrow cells when tested, in male and female Wistar rats, to the maximum tolerated oral dose of 2000 mg.kg-l day-l given as 2 equal daily sub-doses 6 h apart for 2 consecutive days.

The toxicokinetic analysis indicated that the males dosed with 500, 1000 and 2000 mg.kg-l.day-l had mean plasma levels of 76.7*3.9, 98.9+30.7 and 265fl 33 pg.ml-i respectively 1.5 h after the last sub-dose. The females dosed with 2000 mg.kg-l.day-l were found to have plasma levels of 393*6 pg.ml-l 1.5 h after the last sub-dose.

This study was performed in accordance with the Principles of Good Laboratory Practice.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Additional information

Justification for classification or non-classification

Categories Display