Glycerides, castor-oil mono-, di- and tri-

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference 1

Reference Type:

other: NTP summary information

Title:

Unnamed

Year:

1987

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

GLP compliance:

yes

Remarks:

NTP study

Type of assay:

other: Chromosome aberration assay in mamalian cells

Test material

Test material information

Constituent 1

Reference substance name:

Castor oil

EC Number:

232-293-8

EC Name:

Castor oil

Cas Number:

8001-79-4

IUPAC Name:

Castor Oil

Specific details on test material used for the study:

Name as cited in study report: Castor oil

Method

Species / strain

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Details on mammalian cell type (if applicable):

To assess induction of CA, cells were harvested in their first mitotic division after the initiation of chemical exposure.

MEDIA USED
McCoy's 5A medium supplemented with fetal calf serum, L-glutamine, and antibiotics; Colcemid

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced Sprague Dawley rat liver S9-mix

Test concentrations with justification for top dose:

1600, 3000 and 5000 µg/mL

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

DMSO 10 µg/mL

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

mitomycin C

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Without S9-mix: cells were incubated with study compound or solvent for 10 h at 37°C. Cells were then washed and fresh medium containing colcemid was added for an additional 3 h followed by harvest.
- With S9-mix: cells were incubated with study compound or solvent for 2 h at 37°C. Cells were then washed, medium without test compound was added, and incubation was continued for 10 h. Colcemid was added for the last 3 h of incubation before harvest.
- Expression time (cells in growth medium): 12 (without metabolic activation) or 13 hours (with metabolic activation).

SPINDLE INHIBITOR: colcemid

STAIN (for cytogenetic assays): The cells were harvested by mitotic shake-off, fixed, and stained with 6% Giemsa

NUMBER OF CELLS EVALUATED: 200 or 50 for the high dose positive control

Evaluation criteria:

For a single trial, a statistically significant (P<0.05) difference for one dose point and a significant trend (P<0.015) was considered weak evidence for a positive response; significant differences for two or more doses indicated the trial was positive. A strong trend (P < 0.003) with a single significant dose level was designated weak positive *, to indicate a high level of induced aberrations. A strongly positive trend (P < 0.003), in the absence of a statistically-significant increase at any one dose point, led to an equivocal call. Ultimately, the trial calls were based on a consideration of the statistical analyses as well as the biological information available to the reviewers. Trials that gave a weak positive or positive result were repeated. The overall result for the CA assay was based on an evaluation of the responses in all trials within an activation condition.

Statistics:

To arrive at a statistical call for a trial, analyses were conducted to assess the presence of a dose-response (trend test) and the significance of the individual dose points compared to the vehicle control

Results and discussion

Test results

Key result

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid