Suppression of UV-Induced Erythema by Topical Treatment with Melatonin

Abstract

The UV-suppressive effect of topical melatonin was assessed at different application time points in a double-blind randomized clinical trial. The lower back of 20 healthy volunteers was treated with 0.6 mg/cm² melatonin or vehicle either 15 min before or 1, 30 or 240 min after UV irradiation. The erythema was evaluated visually and measured by chromametry 24 h after irradiation. UV-absorbing effects of melatonin were measured at a concentration of 8 µg/ml with a spectrophotometer. Melatonin absorbs UV light at a wavelength of 225–275 nm which is clearly below the wavelength of UVA and UVB (290–390 nm). The visual score showed that application of melatonin 15 min before irradiation significantly suppressed erythema compared to treatment with vehicle alone (p < 0.001). Similar results were found by chromametry (p < 0.001). Treatment after irradiation showed no UV suppression. The erythema suppressive effect of melatonin might be explained by the radical-scavenging mechanism of quenching meanly hydroxyl radicals (·OH) which are known to be most present in sunburn reaction of the skin. The protective effect of the pre-irradiation treatment might be explained by penetration into the skin within 15 min and the presence in a local concentration at the irradiation time point.

Melatonin reduces ultraviolet-B induced cell damages and polyamine levels in human skin fibroblasts in culture

“…About 26% of cultured dermal fibroblasts were only survived at 200 mJ/cm 2 . The UVB induced cytotoxicity is a rapid event, and melatonin prevents such damage when present at concentration of 1 nM (Fischer et al, 1999). In our study, the protective effect of melatonin was observed at concentration of 1 µM and 100 nM.…”

Melatonin's protective effect against UV radiation: a systematic review of clinical and experimental studies

“…Fischer et al . showed that cream containing 0.5% melatonin had no effect when applied after UVR. This is in accordance with Dreher et al .…”

“…Fischer et al (37) showed that cream containing 0.5% melatonin had no effect when applied after UVR. This is in accordance with Dreher et al (39), who showed no significant effect of melatonin, vitamin E or vitamin C adminis-tered alone or in combination when applied after exposure to UVR.…”

Dermatoendocrinology

“…Die aktuelle Anwendung von 0,5% Melatonin-Nanokolloidalgel scheint einen Schutz gegen die Bildung von UVBausgelösten Erythemen zu bewirken [73]. Diese Wirkung könnte für die Verhinderung des Hautalterns nützlich sein.…”