The Sun Protective Effect of Melatonin

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

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.

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.

One square on the back of each volunteers will be randomized to have the above mentioned dose of melatonin cream applied

One square on the back of each volunteers will be randomized to have the above mentioned dose of melatonin cream applied.

One square on the back of each volunteers will be randomized to have the above mentioned dose of melatonin cream applied.

One square on the back of each volunteers will be randomized to have placebo cream (vehicle) applied.

Reduction of erythema assessed by digital image analysis (Image J) after treatment with melatonin/placebo before sun exposure.

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.

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.