p-nonylphenol

Genetic toxicity: in vitro

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

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

Test material information

Constituent 1

Reference substance name:

p-nonylphenol

EC Number:

203-199-4

EC Name:

p-nonylphenol

Cas Number:

104-40-5

Molecular formula:

C15H24O

IUPAC Name:

4-nonylphenol

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 / cell type:

other: CHO-K1 cells

Details on mammalian cell type (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 / cell type 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 / solvent:

DMSO (Dimethyl sulfoxide)

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

mitomycin C

Details on test system and experimental 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 / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

No data available

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

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 37◦C 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).