Rectified Essential Oil of Pogostemon cablin (Lamiaceae) with high content in alpha and delta guaiene obtained from leaves by distillation.

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 August 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Study conducted according to OECD Guideline 439 with deviations: details of test system, volume of test item/negative/positive controls and historical data not reported

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

details of test system, volume of test item/negative/positive controls and historical data not reported

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Rectified Essential Oil of Pogostemon cablin (Lamiaceae) with high content in alpha and delta guaiene obtained from leaves by distillation.

EC Number:

947-393-3

Molecular formula:

Not applicable (UVCB)

IUPAC Name:

Rectified Essential Oil of Pogostemon cablin (Lamiaceae) with high content in alpha and delta guaiene obtained from leaves by distillation.

Test material form:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Robertet S.A. / 1928083

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

other: Reconstructed Human Epidermidis (RHE) Model

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: Reconstructed Human Epidermidis (RHE) Model

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: Room temperature (RT, comprised between 18-24 °C)
- Temperature of post-treatment incubation: 37 °C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Exposure to the test substance was followed by rinsing with phosphate buffer saline (PBS) and mechanically dried.

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- Epidermis were then transferred to fresh medium and incubated at 37 °C for 42 additional hours.
- Cell viability is assessed by incubating the tissues for 3 hours with 0.3 mL MTT solution (1 mg/mL). The formazan crystals are extracted using 1.5 mL isopropanol for 2 hours at RT and quantified by spectrophotometry at 570 nm wavelength.

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability: For each treated tissue, the cell viability is expressed as the percentage of the mean negative control tissues.

NUMBER OF REPLICATE TISSUES:
- Three tissues replicates for test item, negative and positive controls

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be irritant to skin if [the mean relative viability after 42 minutes exposure and 42 hours post incubation is ≤ 50% of the negative control].
- The test substance is considered to be non-irritant to skin [if the mean relative viability after 42 minutes exposure and 42 hours post incubation is > 50% of the negative control].
- A cut-off value of 50% viability of the negative control value was considered and used to classify test substances as irritant (I) or non-irritant (NI). The culture environment might allow the detection of very small quantities of cytokines secreted by the epidermis in response to topical application of test substances.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Test item was topically applied on three tissues replicates for 42 minutes at room temperature (RT, comprised between 18-24 °C).

Duration of treatment / exposure:

Test item was topically applied for 42 minutes at room temperature (RT, comprised between 18-24 °C).

Duration of post-treatment incubation (if applicable):

42 hours at 37 °C

Number of replicates:

Three tissues replicates for test item, negative and positive controls

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

42 minutes exposure

Value:

106.1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

TISSUE VIABILITY:
The mean percent tissue viability of the treated tissues was 106.1%, versus 1.3% in the positive control (5% Sodium Dodecyl Sulfate).

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes; The negative control data meet the acceptance criteria if the mean OD value of the 3 tissues is ≥ 1.2 at 570 nm. The Standard Deviation value is considered as valid if it is ≤ 18% according to the Performance Standards (ECVAM SIVS. 2007).
- Acceptance criteria met for positive control: Yes; The positive control data meet the acceptance criteria if the mean viability expressed as % of the NC is < 40 % and the Standard Deviation value is ≤ 18 %.
- Batch acceptance criteria: All test substance data from one batch are considered as valid if both the negative and the positive controls data fulfill the above criteria requirements.
According to these criteria the test is validated.

Any other information on results incl. tables

Table 7.3.1/1: Reconstructed Human Epidermis (RHE) model – results

OD 570 nm	Tissue 1			Tissue 2			Tissue 3			Mean	Mean Tissue Viability (%)	Standard Deviation (%)	Conclusion
PBS (Negative Control)	1.850	1.905	1.904	2.186	2.264	2.277	2.240	2.261	2.309	2.133	100	10.0	Non Irritant
SDS (Positive Control)	0.030	0.031	0.031	0.022	0.022	0.022	0.031	0.032	0.034	0.028	1.3	0.3	Irritant
Patchouli Fraction 290737	2.259	2.256	2.270	2.264	2.307	2.336	2.232	2.231	2.209	2.263	106.1	1.8	Non Irritant

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under these experimental conditions and in accordance with the Regulation (CE) No.1272/2008, the test item was classified as non-irritant.

Executive summary:

An in vitro skin irritation study was performed according to OECD Guideline 439 and in compliance with GLP to evaluate the possible irritating effects of the test item after topical application on in vitro human reconstructed epidermis (SkinEthic RHE model).

 

The test item was applied on three tissues replicates of Reconstructed Human epidermis during 42 minutes, followed by a rinse with PBS and 42 hours post-incubation period at 37 °C. Cell viability was then measured by enzymatic conversion of the vital dye MTT into a blue formazan salt that was  quantitatively measured after extraction from tissues.

 

The mean percent tissue viabilities obtained with the negative control and positive controls were met the acceptance criteria and therefore validate the experiment.

 

The mean percent tissue viability of the treated tissues was 106.1%, versus 1.3% in the positive control (5% Sodium Dodecyl Sulfate).

 

Under these experimental conditions and in accordance with the Regulation (CE) No.1272/2008, the test item was classified as non-irritant.