3-icosyl-4-henicosylidene-2-oxetanone

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

Study period:

28 May 2004 - 24 August 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Recent study performed according to OECD 473 (1997) and GLP principals.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

no

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

PMC D-532

IUPAC Name:

PMC D-532

Test material form:

other: waxy solid

Details on test material:

- Name of test material (as cited in study report): PMC D-532
- Physical state: waxy solid
- Analytical purity: 86.9% w/w
- Lot/batch No.: 30GT0982
- Expiration date of the lot/batch: 4.8.08
- Stability under test conditions: Stable
- Storage condition of test material: Ambient temperature in the dark

Method

Species / strain

Species / strain / cell type:

lymphocytes: human peripheral blood lymphocyte

Details on mammalian cell type (if applicable):

Human blood samples from healthy, non-smoking donors

Metabolic activation:

with and without

Metabolic activation system:

rat liver-derived metabolic activation system (S9-mix)

Test concentrations with justification for top dose:

50, 300 and 600 micro g/mL (with and without S9) were treated. No analyses of stability, homogeneity or achieved concentration were carried out on the preparations of the test or positive control substances either prior to or after addition to the human peripheral blood lymphocyte cultures.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: acetone

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

cyclophosphamide

mitomycin C

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; in agar (plate incorporation); preincubation; in suspension; as impregnation on paper disk

DURATION
- Exposure duration: 3 hours in the presence and absence of S9-mix and 20 hours in the absence of S9-mix
- Fixation time (start of exposure up to fixation or harvest of cells): 68 hours after the start of treatment (without and with S9).

NUMBER OF REPLICATIONS: 2 in two independent cytogenetic tests

NUMBER OF CELLS EVALUATED: 100

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index

OTHER EXAMINATIONS:
- Determination of polyploidy: No
- Determination of endoreplication: No

Evaluation criteria:

Data were summarized in tables showing the number of cells scored, the types of aberrations found, the frequencies of aberrations per cell and the percentages of cells bearing aberrations. The Fisher Exact Probability Test (one-sided) was used to evaluate statistically the percentage of metaphases showing aberrations (excluding cells with only gap-type aberrations).

Results and discussion

Test results

Species / strain:

lymphocytes: human peripheral blood lymphocyte

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: ca 7
- Effects of osmolality: ca 270 mmol / kg
- Precipitation: The highest concentration selected for chromosomal aberration analysis was the highest practicable concentration. Precipitation of the test substance in the culture medium was noted in cultures treated with PMC D-532 at most of the concentrations tested and in some cases precipitated test substance was also visible on the slides.

No statistically or biologically significant increases in the percentage of aberrant cells, compared to the solvent control values, were recorded in cultures from either experiment treated in the presence of S9-mix or treated for 20 hours in the absence of S9-mix.
A small but statistically significant increase in the percentage of aberrant cells was observed in Experiment 1 at the lowest concentration treated for 3 hours in the absence of S9-mix.

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

It is concluded that, under the conditions of this assay, PMC D-532 is not clastogenic to cultured human lymphocytes treated in vitro in either the presence or absence of S9-mix.