A broad spectrum high-SPF photostable sunscreen with a high UVA-PF can protect against cellular damage at high UV exposure doses.

Abstract

BACKGROUND:

Advances in sunscreen technologies have yielded broad spectrum sunscreens at high-sun protection factor (SPF) and ultraviolet A protection factor (UVA-PF) levels that are photostable and powerful in protecting skin from erythema. Questions arise whether these sunscreens protect proportionally against cellular skin damage caused by high ultraviolet exposures.

OBJECTIVE:

The objective of this study is to evaluate if high-SPF sunscreen can protect skin at a cellular level under UV exposure doses [>50 minimal erythema dose (MED)] similarly to the SPF value.

METHODS:

Sunburn cells, Langerhans cells, thymine dimers, protein 53 (p53), and matrix metalloproteinase (MMP)-1 and MMP-9 endpoints were evaluated in biopsies from 12 subjects following four treatments: unprotected exposed to 0, 1 and 3 MED and sunscreen (SPF 55) protected exposed to 55 MED of UV radiation.

RESULTS:

All the markers showed significantly more damage for the 3 MED-untreated sites when compared with non-irradiated control, and majority of the markers showed marked damage following unprotected 1 MED exposure. After 55 MEDs, sunscreen-protected sites showed significantly less p53 and MMP-9 (keratinocyte) staining than the 1 MED-exposed unprotected sites, while all the other biomarkers in sunscreen protected sites showed no statistical differences from 1 MED-exposed unprotected sites.

CONCLUSIONS:

A high-SPF photostable sunscreen with high UVA-PF can provide proportionately high protection against multiple cellular damage markers.

• Authors: Curtis Cole, Yohini Appa, Hao Ou-Yang
• Journal: Photodermatology, photoimmunology & photomedicine (Photodermatol Photoimmunol Photomed) Vol. 30 Issue 4 Pg. 212-9 (Aug 2014) ISSN: 1600-0781 [Electronic] England
• PMID: 24806442 (Publication Type: Journal Article)
• Copyright: © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Chemical References

• Biomarkers
• Pyrimidine Dimers
• Sunscreening Agents
• TP53 protein, human
• Tumor Suppressor Protein p53
• MMP9 protein, human
• Matrix Metalloproteinase 9
• MMP1 protein, human
• Matrix Metalloproteinase 1

Topics

• Adult
• Biomarkers (metabolism)
• Erythema (metabolism, pathology, prevention & control)
• Female
• Humans
• Langerhans Cells (metabolism, pathology)
• Male
• Matrix Metalloproteinase 1 (metabolism)
• Matrix Metalloproteinase 9 (metabolism)
• Middle Aged
• Pyrimidine Dimers (metabolism)
• Skin (metabolism, pathology)
• Sun Protection Factor
• Sunscreening Agents
• Tumor Suppressor Protein p53 (metabolism)
• Ultraviolet Rays (adverse effects)