The Sun Protective Effect of Melatonin

Study Overview
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Brief Summary
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The aim of this study is to investigate the sun protective effect of melatonin, when used as a cream applied before sun exposure. Sun exposure induces erythema as indication of an inflammatory reaction in the skin. It is proven that the amount of free radicals in the skin are increased by UV exposure. Furthermore, it is known that melatonin is a potent antioxidant. It is hypothesized that melatonin can be protective against the UV induced release of free radicals by acting as a radical scavenger and thereby protect against UV-induced cellular damage.

Detailed Description
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This study investigates the sun protective effect of melatonin when used as a creme applied before sun exposure. The study is a randomized, placebo-controlled, double-blinded study conducted on healthy volunteers. The volunteers will have 5 squares of 8 cm*8 cm on their backs, which each will be randomized to receive one of following: melatonin cream 0,5%; melatonin cream 2,5%; melatonin cream 12,5%; placebo cream (vehicle) and no treatment. After randomization and received treatment the volunteers will be exposed to strong midday sun (UV-index of approximately 9) for 40 minutes. The outcomes parameters (degree of erythema and pain sensation) are measured at baseline and 1,4,8 and 24 hours post exposure.

Official Title
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The Sun Protective Effect of Melatonin: a Randomized, Placebo-controlled, Double-blind Study on Healthy Volunteers

Conditions
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Sunburn

Intervention / Treatment
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* Drug: Melatonin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy volunteers of both sexes. Skin type 1-3 according to Fitzpatrick skin type scale. No sun exposure on skin area tested in the study 4 weeks prior to the study. Exclusion Criteria: Active skin disease Participant that do not react to the given sun exposure with a change in a-value >5 are excluded from the data. Pregnancy Previous malignant or pre malignant skin disease.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Melatonin: Melatonin cream 2,5%<br>One square on the back of each volunteers will be randomized to have the above mentioned dose of melatonin cream applied | Drug: Melatonin<br> <br> |
| Active Comparator: Melatonin: Melatonin cream 0,5%<br>One square on the back of each volunteers will be randomized to have the above mentioned dose of melatonin cream applied. | Drug: Melatonin<br> <br> |
| Active Comparator: Melatonin: Melatonin cream 12,5%<br>One square on the back of each volunteers will be randomized to have the above mentioned dose of melatonin cream applied. | Drug: Melatonin<br> <br> |
| Placebo Comparator: placebo cream<br>One square on the back of each volunteers will be randomized to have placebo cream (vehicle) applied. | |
| No Intervention: No treatment<br>One square on the back of each volunteers will be randomized to receive no treatment. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduction of erythema assessed by digital image analysis (Image J) after treatment with melatonin/placebo before sun exposure. | The alpha value measured in a color space converted image will represent the degree of erythema | Primary outcome is assessed at: baseline and 1,4,8 and 24 hours post exposure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Testing for primary hyperalgesia in the sun exposed area with Pin-Prick monofilaments. Testing for primary hyperalgesia in the sun-exposed area with Pin-Prick monofilaments. |  | The secondary outcome is assessed at: baseline and 1,4,8 and 24 hours post exposure. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Melatonin, Sunburn, Erythema, Sunlight, Ultraviolet rays