Oxaceprol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Oxaceprol did not show genetic toxicity in studies according to OECD 471 (Ames test) (in vitro gene mutation study in bacteria) and an in vitro cytogenicity study in mammalian cells.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2000-02-02 to 2001-08-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Kyowa Hakko Kogyo Co., Ltd. / lot 000703

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature in the dark
- Solubility and stability of the test substance in the solvent/vehicle: highly soluble

Target gene:

Histidine mutation: His C3076, His D3052, His G46
Additional mutations: LPS (rfa), Repair (uvrB), R-factor (plasmid pKM 101)

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Remarks:

WP2uvrA-

Metabolic activation:

with and without

Metabolic activation system:

S9-mix

Test concentrations with justification for top dose:

Preliminary toxicity study: 0, 0.15, 0.5, 1.5, 5, 15, 50, 150, 1500 and 5000 µg/plate
Range finding study: 50, 150, 1500 and 5000 µg/plate
Main study: 50, 150, 1500 and 5000 µg/plate Justification for top dose: Results of preliminary study and range finding study

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: Oxaceprol is highly soluble in water

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

N-ethyl-N-nitro-N-nitrosoguanidine

other: In addition, historical values

Details on test system and experimental conditions:

METHOD OF APPLICATION: (plate incorporation); preincubation

DURATION
- Exposure duration: 48 h

SELECTION AGENT (mutation assays): base pair substituation and frameshift type

NUMBER OF REPLICATIONS: 3 per concentration

Evaluation criteria:

The test material may be considered positive in the test system if the following criteria is met:

The test material should have induced a reproducible, dose-reated and statistically [Dunnett's method of linear regression (5)] significant increase in the revertant count in at least one strain of bacteria.

Key result

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2uvrA-

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

not valid

Additional information on results:

From the results obtained in the experiments it appeared that incubation of the test substance with the bacteria did not increase the number of his+ revertants with S. typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100 and WP2uvrA-, either in the absence or in the presence of the S-9 mix.

The test substance appeared not to be toxic.

The positive controls used in the present assays gave the expected strong increase in the number of his+ revertants, both in the absence and in the presence of the S-9 mix.

Remarks on result:

no mutagenic potential (based on QSAR/QSPR prediction)

Conclusions:

Oxaprenol is considered to be non-mutagenic under the condistions of the test.

Executive summary:

The potential of causing genetic toxicity by Oxaceprol was investigated in a Stuy according to OECD 471 (Ames-test).

From the results obtained in the experiments it appeared that incubation of the test substance with the bacteria did not increase the number of his+ revertants with S. typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100 and WP2uvrA-, either in the absence or in the presence of the S-9 mix.

The test substance appeared not to be toxic.

The positive controls used in the present assays gave the expected strong increase in the number of his+ revertants, both in the absence and in the presence of the S-9 mix.

Reference 2

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001-01-24 to 2001-11-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

other: Requirements of the Japanese Chemical Substance Law (METI) for assessing chromosomal mutagenicity of a test material on the metaphase of the Chinese Hamster Lung (CHL) cell. Method similar to OECD 473.

GLP compliance:

yes (incl. QA statement)

Type of assay:

other: In vitro chromosome aberration test

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Kyowa Hakko Kogyo Co., Ltd. / batch 000703

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature, in the dark
- Solubility and stability of the test substance in the solvent/vehicle: highly soluble

Species / strain / cell type:

other: Chines Hamster LUng (CHL) cells

Details on mammalian cell type (if applicable):

The HL cell line, isolated by Koyame et al. (1970) and cloned by Ishidate and Sofuni (1985) was used. The CHL cell line has an average generation time ox approximately 17 h when growing under normal experimenatl conditions.

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

Preliminary toxicity test (cell growth inhibition test): 6.76 to 1730 µg/ml.
Main tests: 0, 216.25, 432.5, 865, 1730 µg/ml. Justification for top dose: Results from preliminary toxicity test.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: Oxaceprol is highly soluble in water

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

cyclophosphamide

mitomycin C

Remarks:

In addition: Historical data on controls

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Preincubation period: 16 - 72 h
- Exposure duration: 24 h, 48 h

NUMBER OF REPLICATIONS: 2 per concentration


CRITERIA FOR MICRONUCLEUS IDENTIFICATION:

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index, cell counts

Evaluation criteria:

In all circumstances where increase in the frequency of cells with aberrations are seen, statistical comparisons will be made with the vehicle. A positive response was recorded for a particuliar treatment if the percentage of cells with aberrations, excluding gaps, makredly exceeded that seen in the concurrent control, either with or without a clear dose-relationship. For modest increases in aberation frequency a dose response relationship is generally required and appropriate statistical tests may be applied in order to record a positive response.

Statistics:

Not required.

Key result

Species / strain:

other: Chinese Hanster Cells (CHL)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no mutagenic potential (based on QSAR/QSPR prediction)

Conclusions:

Oxaceprol did not induce any statistically significant, dose-related increases in the frequency of cells with chromosome aberrations either in the presence of a liver enzyme metabolising system or after various exposre times. Therefore Oxaceprol is cosidered to be non-clastogenic to CHL cells in vitro.

Executive summary:

An in vitro cytogenicity study in mammalian cells was performed in order to assess the potentil chromosome mutagenicity of Oxaceprol. The test was performed in accordance with the requirements of the Japanes New Chemical Suvstance Law (METI). The test method is similiar to the OECD guideline 473.

Oxaceprol did not induce any statistically significant, dose-related increases in the frequency of cells with chromosome aberrations either in the presence of a liver enzyme metabolising system or after various exposure times. Therefore Oxaceprol is considered to be non-clastogenic to CHL cells in vitro.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Justification for classification or non-classification

Oxaceprol did not show genetic toxicity in studies according to OECD 471 (Ames test) (in vitro gene mutation study in bacteria) and an in vitro cytogenicity study in mammalian cells.