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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Data is from peer reviewed journal

Data source

Reference
Reference Type:
publication
Title:
Genotoxic effects of environmental estrogen-like compounds in CHO-K1 cells
Author:
Sumiko Tayama, Yoshio Nakagawa, Kuniaki Tayama
Year:
2008
Bibliographic source:
Mutation Research 649 (2008) 114–125

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: refer below principle
Principles of method if other than guideline:
Study access to determine the chromosome aberration by test chemical p-nonylphenol(NP)
GLP compliance:
not specified
Type of assay:
in vitro mammalian chromosome aberration test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous
Details on test material:
- Name of test material (as cited in study report): p-nonylphenol(NP) (104-40-5)
- Molecular formula (if other than submission substance): C15-H24-O
- Molecular weight (if other than submission substance): 220.354 g/mol
- Substance type: Organic
- Physical state: Liquid
- Purity: >97%
- Impurities (identity and concentrations): No data available

Method

Species / strain
Species / strain:
other: CHO-K1 cells
Details on mammalian cell lines (if applicable):
- Type and identity of media: Ham’s F-12 medium supplemented with 10% fetal bovine serum, penicillin (100 U/ml), and streptomycin (100 µg/ml).
- Properly maintained: No data available
- Periodically checked for Mycoplasma contamination: No data available
- Periodically checked for karyotype stability: No data available
- Periodically "cleansed" against high spontaneous background: No data available
Additional strain characteristics:
not specified
Metabolic activation:
not specified
Test concentrations with justification for top dose:
0,0.025,0.05,0.075,0.1 mM
Vehicle:
DMSO (Dimethyl sulfoxide)
Controls
Negative controls:
not specified
Solvent controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
mitomycin C
Details on test system and conditions:
METHOD OF APPLICATION: in tissue culture flask
DURATION
- Preincubation period: No data
- Exposure duration: 3hrs
- Expression time (cells in growth medium): 27 hrs
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays):No data
SPINDLE INHIBITOR (cytogenetic assays): Colcemid
STAIN (for cytogenetic assays): fluorescence-plus-Giemsa (FPG)-method

NUMBER OF REPLICATIONS: 2 rounds of replications

NUMBER OF CELLS EVALUATED: 6X105 cells

DETERMINATION OF CYTOTOXICITY
- Method: Differently staining sister-chromatids

OTHER EXAMINATIONS:
- Determination of polyploidy: Yes
- Determination of endoreplication: Yes
- Other: No data available

OTHER: No data available
Evaluation criteria:
For CA (Chromosome aberration) and DSC (differently staining sister-chromatids), 100 metaphases were observed , for ERD (Endoreplication) and 200 metaphases were observed.
Statistics:
Chi-square test

Results and discussion

Test results
Species / strain:
other: CHO-K1 cells
Metabolic activation:
not specified
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
not specified
Negative controls valid:
not specified
Positive controls valid:
not specified
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Additional information on results:
No data available

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The endpoint for the genetic toxicity test was found to be negative for CHO-K1 cells when treated with p-nonylphenol (104-40-5)
Executive summary:

The genetic toxicity test was performed on CHO-K1 cells using chromosome Aberration (CA) test. p-nonylphenol is of >97% and dissolved in dimethyl sulfoxide.

CHO-K1 cellswere grown at 37C in plugged tissue cultureflasks that contained Ham’s F-12 medium.About 6×105cells were seeded into tissue-culture flasks (40 cm2) containing 10 ml of medium and cultured. After 48 h, 5ml of medium containing each chemical were added, and the culture was incubated for 3 h or 1 h (H2O2) and then washed. Ten milliliters of medium containing 5-bromo-2 deoxyuridine at a final concentration of 0.5µg/ml were added to each culture, and the cultures were incubated in the dark for 27 h (two rounds of replication), after which they were harvested. Two hours before harvesting, Colcemid was added to the medium at a final concentration of 0.1µg/ml.

 

After the cells had been collected, hypotonic treatment, fixation and preparation, and staining with fluorescence-plus-Giemsa method were performed and Cas and endoreduplication (ERD) were observed. Differently staining sister-chromatids (DSC) was also examined as an indicator of cytotoxic effects. For CA and DSC, 100 metaphases were observed; for ERD and c-mitosis like changes, 200 metaphases were observed and analysis was performed using Chi-square test.

 

 

From the above table it was interpreted that theendpoint for the genetic toxicity test was found to be negative for CHO-K1 cells when treated with p-nonylphenol (104-40-5).