Cholesterol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July-October 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Cholesterol

EC Number:

200-353-2

EC Name:

Cholesterol

Cas Number:

57-88-5

Molecular formula:

C27H46O

IUPAC Name:

cholest-5-en-3-ol

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): cholesterol
- Physical state: white powder
- Storage condition of test material: at room temperature in the dark

Test animals

Species:

other: human epidermis model (human-derived epidermal keratinocytes)

Details on test animals or test system and environmental conditions:

test system:
three-dimensional human epidermis model, consisting of adult human-derived epidermal keratinocytes, seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen. The keratinocytes were cultured for 13 days, resulting in a highly differentiated and stratified epidermis model comprising the main basal, supra basal, spinous and granular layers and a functional stratum corneum.

source:
SkinEthic Laboratories, Lyon, France.

Test system

Type of coverage:

other: in vitro system

Amount / concentration applied:

TEST MATERIAL
- Amount applied (volume or weight with unit): 10.2 to 11.5 mg cholesterol.

Duration of treatment / exposure:

15 minutes at room temperature, post-incubation for 42 hours at 37°C.

Details on study design:

Cytotoxicity (irritancy) is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of treatment.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: other: cytotoxicity

Value:

102

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 15 minutes exposure. Reversibility: other: not relevant. Remarks: in vitro study. (migrated information)

In vivo

Irritant / corrosive response data:

mean tissue viability:
negative control: 100%
cholesterol: 102%
pos control: 5%

Any other information on results incl. tables

acceptability of the assay.

the test is considered acceptable if it meets the following criteria:

-the absolute mean optical density at 570 nm of the three tissues of the negative control should reasonably be within the laboratory historical control data range and the SD value of the % viability should be ≤18

-the mean relative tissue viability of the positive control should be ≤40% relative to the negative control and the SD value of the % should be ≤18

-the SD calculated from individual % tissue viabilities of the three identically treated replicates should be ≤18

A test substance is considered irritant in the skin irritation test if:

The relative mean tissue viability of three individual tissues after 15 minutes of exposure to the test substance and 42 hors of post-incubation is ≤50% of the mean viability of the negative controls.

A test substance is concidered non-irritant in the skin irritation test if:

The relative mean tissue viability of three individual tissues after 15 minutes of exposure to the test substance and 42 hours of post incubation >50% of the mean viability of teh negative controls.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Cholesterol is non-irritant in a valid in vitro skin irritation test.

Executive summary:

Cholesterol was tested for skin irritaing potential with a human three dimensional epidermal model (EPISKIN-Small Model). 10.2 to 11.5 mg cholesterol was applied directly on top of the skin tissue for 15 minutes, and after a 42 hours post-incubation period the cytotoxic effect (as indicator for irritancy) was determined by means of the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT. Mean relative tissue viability above 50% is considered non-irritant. Adequate positive and negative controls were included. The relative mean tissue viability after treatment with cholesterol compared to the negative control tissue was 102%. Based on these results, cholesterol is considered non-irritant in this in vitro test.