Coffee, bean, roasted, ext.

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

other: patch test for skin irritation

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Are coffee silverskin extracts safe for topical use? An in vitro andin vivo approach.

Author:

Rodrigues F et al.,

Year:

2015

Bibliographic source:

Industrial Crops and Products 63 (2015) 167–174

Materials and methods

Study type:

study with volunteers

Endpoint addressed:

skin irritation / corrosion

Test guideline

Qualifier:

no guideline required

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

not applicable - High molecular weight constituents (Mwt > 719 g mol-1) such as polysaccharides, proteins and melanoidin polymers

Molecular formula:

not applicable - High molecular weight constituents (Mwt > 719 g mol-1) such as polysaccharides, proteins and melanoidin polymers

IUPAC Name:

not applicable - High molecular weight constituents (Mwt > 719 g mol-1) such as polysaccharides, proteins and melanoidin polymers

Constituent 2

Reference substance name:

Caffeine

EC Number:

200-362-1

EC Name:

Caffeine

Cas Number:

58-08-2

Molecular formula:

C8H10N4O2

IUPAC Name:

1,3,7-trimethyl-3,7-dihydro-1H-purine-2,6-dione

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: coffee silver skin samples were provided by a national coffee roaster (BICAFÉ –Portugal).
- Expiration date of the lot/batch: not available
- Purity test date: not available


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: not available
- Stability under test conditions: not available
- Solubility and stability of the test substance in the solvent/vehicle: not available
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not available

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: coffee silver skin was milled to particle size of approximately 0.1 mm using a A11 basic analysis mill (IKA Wearke, Staufen, Germany) and stored in silicone tubes at room temperature (25–28ºC) until extract preparation. Samples (1 g) were submitted to solvent extraction by maceration with ethanol: water (1:1 v/v) for 30 min at 40ºC. The extract obtained was filtered through Whatman No. 1 paper filter and the filtrate collected.
- Preliminary purification step (if any): not applicable
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid: not applicable


OTHER SPECIFICS: none

Method

Subjects:

- Number of subjects exposed: 20
- Sex: 15 women and 5 men
- Age: 30 ± 5 years
- Race: not specified
- Demographic information: not specified
- Known diseases: without known dermatological diseases or allergy to substances in topical products
- Other: none

Ethical approval:

confirmed and informed consent free of coercion received

Route of exposure:

dermal

Reason of exposure:

intentional

Details on exposure:

The volunteers were asked to not apply any topical products in the forearms 24 h before the beginning and throughout the test period. Additionally, solar exposure was forbidden.
Along with coffee silverskin extracts (water/ethanol 1:1 v/v), SLS (2%, w/v, aqueous solution) and purified water were also assayed respectively, as positive and negative control. Fifty microlitres of the test solutions were applied on a filter paper disc (12 mm) and occlusion was achieved with aluminum chambers (12 mm). Patches were removed after 48 h, and following a period of 2 h of observation patch test areas were evaluated by non-invasive measuring methods and visual scoring.

Examinations:

Prior to application, the basal skin values were evaluated by non-invasive measuring methods and post application by visual scoring and non-invasive measuring methods.
The visual assessment of the degree of irritation was graded according to the following scale: 0 – no reaction; 1 – weak, spotty erythema; 2 – well perceptible erythema covering the total exposure area; 3 – moderate erythema or severe erythema that covers the total exposure area. The same scale was used for edema: 0 – no reaction; 1 – weak, spotty edema; 2 – well perceptible edema covering the total exposure area; 3 – moderate or severe edema that covers the total exposure area.
Non-invasive biophysical measurements were performed in controlled temperature of 21–22ºC and relative humidity of 45–55%. Barrier function was evaluated by Transepidermal water loss (TEWL) measurements, carried out with a Tewameter®TM 210, which measures the relative humidity percentage, which diffuses from the dermis to the skin surface (g/cm2h).

Results and discussion

Clinical signs:

Results of patch test demonstrated that hydro-alcoholic extract provoked a slight erythema in three volunteers 2 h after the patch test removal; however, the statistical analysis did not reveal any differences from negative control.

Any other information on results incl. tables

No significant differences were observed for trans-epidermal water loss (TEWL) measurements, in comparison with purified water, 2 h after patch removal (p < 0.05), indicating the absence of barrier disruption.

Applicant's summary and conclusion

Conclusions:

In the single-blind patch tests in human volunteers, performed with the hydro-alcoholic extract of coffee silverskin no signs of skin irritation were observed.

Executive summary:

A single-blind study was performed in order to evaluate the in vivo skin irritation potential of hydro-alcoholic extract of coffee silverskin.

Twenty healthy individuals (15 women and 5 men), without known dermatological diseases or allergies to substances in topical products participated in the study.

Sodium lauryl sulfate and purified water served as positive and negative control, respectively.

Patches with the test solutions were applied for 48 hours and following 2-hour observation period, patch test areas were evaluated by visual scoring and trans-epidermal water loss measurement.

Results of patch test demonstrated that hydro-alcoholic extract provoked a slight erythema in three volunteers 2 h after the patch test removal; however, the statistical analysis did not reveal any differences from negative control.

No significant differences were observed for trans-epidermal water loss measurements, in comparison with purified water, indicating the absence of barrier disruption.