Photoprotective effect of topically applied superoxide dismutase on sunburn reaction in comparison with sunscreen.

Photoprotective effect of topically applied superoxide dismutase (SOD) to guinea pig skin was compared with a commercially available sunscreen agent after a single exposure to UVB. While cutaneous SOD activity was remarkably decrease in non-treated control animals, both topical SOD and sunscreen agent significantly reduced the decrease in skin SOD activity after UVB irradiation. However, only the sunscreen agent successfully reduced erythema reaction 24h after irradiation but topical SOD failed. These findings suggest that topical SOD protects skin from photo-oxidative damage without affecting erythema response, and thus, from a practical standpoint, sunscreen agents, when compared with topical antioxidants, seem better at present for daily photoprotection.