Ultraviolet B-Induced Skin Erythema
Conditions
Keywords
Garcinia mangostana, Mangosteen Pericarp Extract, Narrowband Ultraviolet B, UVB Photoprovocation, Skin Erythema, Skin Redness, Reflectance Colorimetry
Brief summary
This study examined whether a gel containing mangosteen (\*Garcinia mangostana\*) pericarp extract could reduce short-term skin redness caused by narrowband ultraviolet B (NB-UVB) exposure when applied before irradiation. Healthy adults aged 20-45 years with Fitzpatrick skin phototype III or IV participated. Six small test sites were marked on each participant's back. Each site was assigned to one of six conditions: mangosteen gel containing 5%, 10%, or 20% extract; gel base without extract; NB-UVB exposure without topical treatment; or no topical treatment and no NB-UVB exposure. Because all six conditions were evaluated in the same participant, each participant served as their own control. The active gels and gel base were applied 20 minutes before NB-UVB exposure. The ultraviolet dose was based on each participant's individual skin sensitivity. Skin redness and lightness were measured with a color-measuring instrument before exposure and at 12, 24, and 48 hours afterward. The investigator performing the skin-color measurements was not informed which condition had been assigned to each test site.
Detailed description
This was a single-center, randomized, outcome-assessor-blinded, within-participant controlled photoprovocation study in healthy adults. The study evaluated the effect of topical gel formulations containing 5%, 10%, or 20% ethanolic \*Garcinia mangostana\* pericarp extract on the early skin-color response to narrowband ultraviolet B exposure. Six adjacent 1.9 × 1.9 cm test sites were identified on clinically normal skin of each participant's back. The six study conditions were allocated among the test sites within each participant: 5% mangosteen gel plus NB-UVB, 10% mangosteen gel plus NB-UVB, 20% mangosteen gel plus NB-UVB, vehicle gel plus NB-UVB, irradiated untreated control, and nonirradiated untreated control. Before the experimental exposure, each participant's minimal erythema dose was determined. Approximately 10 mg of the assigned active gel or vehicle, corresponding to approximately 2.77 mg/cm², was applied to the relevant test site 20 minutes before irradiation. The active-gel, vehicle-treated, and irradiated untreated sites were exposed to narrowband UVB at twice the participant's individual minimal erythema dose. The nonirradiated untreated site received neither topical preparation nor NB-UVB exposure. Skin color was assessed using a Konica Minolta CR-400 chromameter before irradiation and at 12, 24, and 48 hours after exposure. Three measurements were obtained from each test site at each assessment. The a\* coordinate was used to quantify change in skin redness, and the L\* coordinate was used to assess change in skin lightness. The principal comparison evaluated differences in change in a\* among the active formulations, vehicle-treated irradiated skin, and untreated irradiated skin. Change in L\* was evaluated as a secondary colorimetric outcome. The investigator performing the colorimetric assessments was unaware of the condition assigned to each test site. Local tolerability and adverse events were monitored throughout the study.
Interventions
The hydrophilic gel vehicle, containing the same base formulation but no Garcinia mangostana pericarp extract, was applied once to a randomly allocated 1.9 × 1.9-cm test site at a dose of 10 mg per site (approximately 2.77 mg/cm²). The vehicle was applied 20 minutes before narrowband ultraviolet B irradiation at twice the participant's individually determined minimal erythema dose.
RADIATIONNarrowband Ultraviolet B Irradiation
Narrowband ultraviolet B irradiation, with an emission peak of approximately 311 nm, was administered at twice each participant's individually determined minimal erythema dose. Irradiation was delivered to the three active-gel sites, the vehicle-treated site, and one untreated irradiated control site. A sixth untreated control site was not irradiated.
A hydrophilic gel containing 5% ethanolic Garcinia mangostana L. pericarp extract was applied once to a randomly allocated 1.9 × 1.9-cm test site on the participant's back at a dose of 10 mg per site (approximately 2.77 mg/cm²). The gel was applied 20 minutes before narrowband ultraviolet B irradiation at twice the participant's individually determined minimal erythema dose.
A hydrophilic gel containing 10% ethanolic Garcinia mangostana L. pericarp extract was applied once to a randomly allocated 1.9 × 1.9-cm test site on the participant's back at a dose of 10 mg per site (approximately 2.77 mg/cm²). The gel was applied 20 minutes before narrowband ultraviolet B irradiation at twice the participant's individually determined minimal erythema dose.
DRUGTopical Garcinia mangostana Pericarp Extract Gel 20%
A hydrophilic gel containing 20% ethanolic Garcinia mangostana L. pericarp extract was applied once to a randomly allocated 1.9 × 1.9-cm test site on the participant's back at a dose of 10 mg per site (approximately 2.77 mg/cm²). The gel was applied 20 minutes before narrowband ultraviolet B irradiation at twice the participant's individually determined minimal erythema dose.
Sponsors
Hasanuddin University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Masking description
The investigator performing the colorimetric assessments was unaware of the condition assigned to each test site. A separate investigator applied the formulations and retained the site-allocation list. Participants and the investigator applying the formulations were not masked.
Intervention model description
This study used a randomized six-condition within-participant design. Each participant contributed six separate test sites on the back and received all six study conditions concurrently, with one condition assigned to each site. Randomization was performed at the skin-site level rather than at the participant level. Each participant therefore served as their own control, and the six arms represent test-site conditions rather than separate groups of participants.
Eligibility
Sex/Gender
ALL
Age
20 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
Adults aged 20-45 years. Fitzpatrick skin phototype III or IV. In good general health, without an acute or chronic medical condition. Clinically normal back skin without erythema or pathological lesions at the proposed test sites. Able and willing to provide written informed consent.
Exclusion criteria
History of atopic disease. Uneven pigmentation at the proposed test sites. Open wounds at the proposed test sites. Current use of topical or systemic corticosteroids or antihistamines. History of photosensitivity or polymorphic light eruption. History of malignancy within the previous 5 years. Pregnancy or breastfeeding. Sunbathing or use of a tanning bed within the previous 4 weeks. Known hypersensitivity to mangosteen or any component of the study gel.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Skin Redness Assessed by the CIELAB a* Coordinate | Baseline and 12, 24, and 48 hours after narrowband ultraviolet B exposure | Skin redness was measured using a calibrated CR-400 chromameter (Konica Minolta, Japan). Three consecutive measurements were obtained at each test site and averaged. Change in redness was calculated as Δa\* = post-exposure a\* minus baseline a\*. Higher positive Δa\* values indicate a greater increase in skin redness. Changes were compared across the three mangosteen gel sites, vehicle-treated irradiated site, untreated irradiated site, and nonirradiated untreated site within each participant. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Skin Lightness Assessed by the CIELAB L* Coordinate | Baseline and 12, 24, and 48 hours after narrowband ultraviolet B exposure | Skin lightness was measured using a calibrated CR-400 chromameter (Konica Minolta, Japan). Three consecutive measurements were obtained at each test site and averaged. Change in skin lightness was calculated as ΔL\* = baseline L\* minus post-exposure L\*. Higher positive ΔL\* values indicate a greater reduction in skin lightness. Changes were compared across the six study conditions within each participant. |
Countries
Indonesia
Contacts
PRINCIPAL_INVESTIGATORSiswanto Wahab, MD
Hasanuddin University
Outcome results
None listed