The Benefits of Sunscreens: Protective Cellular Effects from Ultraviolet A Rays

• Lipofucsin is the intracellular aggregate of oxidized proteins and lipids. It is a marker of autophagy and is stainable on immunochemistry with Sudan Black B (SBB)
• Ultraviolet A (UVA) damage induces DNA damage, oxidation of proteins and lipids, autophagy and subsequently apoptosis (provided exposure is long enough)
• In this study human cultures of fibroblasts were repeatedly exposed to non-cytotoxic UVA radiation every 2-3 days. Beforehand, half of the cell cultures were treated with a non-cytotoxic sunscreen (concentration of 0.0316 mg/ml)
• After 3 cycles, the cultures were stained

• Results: lipofucsin is almost absent in UVA-irradiated human fibroblast cultures (HFF-1 cells)
• Limitation of the study: done in vitro. Further studies could further demonstrate these results.

Comment: there is a picture of 30 (5×5) wells of irradiated and non-irradiated cell cultures. But no mention is done of the total number of cell cultures.

Contributors

Dr Christophe Hsu – dermatologist. Geneva, Switzerland

Source of information: p391 Sunscreen cosmetic protects human fibroblast cultures against UVA-induced autophagy. Clerici S.P. et al. EADV Annual Meeting (2014), Amsterdam The Netherlands