Reaction Mass of 1,4-dimethyl-7-(prop-1-en-2-yl)-1,2,3,4,5,6,7,8-octahydroazulene and 3,8-dimethyl-5-(prop-1-en-2-yl)-1,2,3,3a,4,5,6,7-octahydroazulene and 4,8a,9,9-tetramethyldecahydro-1,6-methanonaphthalen-1-ol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-03 to 2008-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

LLNA using lymph node cell count instead of [3H]-thymidine incorporation into lymph node cells.

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction Mass of 1,4-dimethyl-7-(prop-1-en-2-yl)-1,2,3,4,5,6,7,8-octahydroazulene and 3,8-dimethyl-5-(prop-1-en-2-yl)-1,2,3,3a,4,5,6,7-octahydroazulene and 4,8a,9,9-tetramethyldecahydro-1,6-methanonaphthalen-1-ol

EC Number:

939-227-3

Cas Number:

84238-39-1

Molecular formula:

Not applicable (a generic Molecular formula cannot be provided for this substance)

IUPAC Name:

Reaction Mass of 1,4-dimethyl-7-(prop-1-en-2-yl)-1,2,3,4,5,6,7,8-octahydroazulene and 3,8-dimethyl-5-(prop-1-en-2-yl)-1,2,3,3a,4,5,6,7-octahydroazulene and 4,8a,9,9-tetramethyldecahydro-1,6-methanonaphthalen-1-ol

Constituent 2

Reference substance name:

282-483-4

IUPAC Name:

282-483-4

Details on test material:

- Name of test material (as cited in study report): Patchouli essential oil
- Physical state: brown liquid
- Analytical purity: not applicable; considered as 100 % for the study
- Origin: Plantae (from Indonesia)
- Binomial family: Labiatae
- Binomial name: Pogostemon cablin

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/J

Sex:

not specified

Details on test animals and environmental conditions:

No data

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

10, 25, 50, 100 % test material

No. of animals per dose:

Four

Details on study design:

- Four groups of four animals were treated for three consecutive days (days 1-3) via topical application to the dorsal surface of each ear.
- Test material was applied as 50 μL (25 μL per ear) of the undiluted test item or the test item as a solution in acetone/olive oil (4:1).
- A group of four animals received the vehicle alone.
- A further group of four animals was treated with the positive control diluted at 25 % in the vehicle.
- On day 6, the proliferation of lymphocytes in the draining auricular lymph nodes was determined by cell counting.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

- The Stimulation Index (SI) was calculated from the formula SI = cell count of treated group / cell count of control group.

Results and discussion

Positive control results:

- A Stimulation Index (SI) of 2.22 was recorded for the positive control diluted at 25 % in the vehicle.
- The SI result was more than 1.4 as expected.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1.01

Test group / Remarks:

10%

Results 2

Parameter:

SI

Value:

1.45

Test group / Remarks:

25 %

Results 3

Parameter:

SI

Value:

2.24

Test group / Remarks:

50%

Results 4

Parameter:

SI

Value:

2.53

Test group / Remarks:

100%

Cellular proliferation data / Observations:

The Stimulation Index (SI) calculated by pooled approach was respectively 1.01, 1.45, 2.24, and 2.53 for the treated groups at 10%, 25%, 50%, and 100%.

Any other information on results incl. tables

- The EC1.4 value determined by linear interpolation of points on the dose-response curve was 23.30 % (see document describing validation of EC value, attached).

- No mortality and no sign of systemic toxicity were noted in the test and control animals during the test.

- A moderate (+15.2%) to important (+41.6%) increase in ear thickness was recorded respectively at the concentration of 50% and 100%. An important increase in ear weight (+60.3%) was recorded at the concentration of 100%.

Applicant's summary and conclusion

Interpretation of results:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Conclusions:

The test material was considered to be a sensitiser under the conditions of the test and showed an EC1.4 of 23.30%.

Executive summary:

A study was performed in accordance with GLP and OECD Guideline 429 to assess the skin sensitisation potential of Patchouli Essential Oil in the CBA/J strain mouse following topical applications of the test material to the dorsal surface of the ear (Robertet Grasse, 2008). Four groups, each of four animals, were treated for three consecutive days with 50 μL (25 μL per ear) of the undiluted test item and the test item as a solution in Acetone/ Olive oil (4:1) at concentrations of 10%, 25%, 50% and 100% (v/v). The Stimulation Index, when using the pooled approach, is expressed as the cell count for each treatment group divided by the cell count of the control group and was 1.01, 1.45, 2.24 and 2.53 at concentrations of 10%, 25%, 50% and 100%, respectively.

The proliferation response of lymph node cells is expressed as the number of lymphocytes per lymph node and as the ratio of lymphocytes into lymph node cells of test nodes relative to that recorded for the control nodes (Stimulation Index). The test item is regarded as a sensitiser if at least one concentration of the test item results is greater than 1.4 compared to control values.

The Stimulation Index (SI) calculated by pooled approach was respectively 1.01, 1.45, 2.24,and 2.53 for the treated groups at 10%, 25%, 50%, and 100%.

The EC1.4 value determined by linear interpolation of points on the dose-response curve was 23.30%.

In view of these results, under these experimental conditions, the test item PATCHOULI EO was considered to be a sensitiser under the conditions of the test.