Protection from solar simulated radiation-induced DNA damage in cultured human fibroblasts by three commercially available sunscreens

Abstract

Exposure to solar radiation can produce both acute and chronic changes in the skin, including sunburn, edema, immunosuppression, premature skin aging, and skin cancer. At the cellular level, solar radiation can produce adverse structural and functional changes in membrane proteins and lipids and in chromosomal and mitochondrial DNA. The increasing awareness of these adverse effects has led the public to demand better photoprotection. In this study, the alkaline comet assay was used to evaluate the photoprotective effects of three commercially available sunscreens at sun protection factors (SPF) 15 and 30. Human fibroblasts were used as target cells to conveniently study the effects of solar simulated radiation on DNA damage in the presence and absence of sunscreens. When human fibroblasts were exposed to various doses of solar simulated radiation, DNA damage, as measured in sunscreen-protected cells by the comet assay, was not significantly different from that detected in unexposed cells. At 1.0 and 1.5 minimal erythemal doses (MED), all sunscreens, at both SPF 15 and 30, provided nearly 100% photoprotection to the fibroblasts. Further studies are required to elucidate the role of UVA in the production and repair of DNA damage in cells exposed to sunlight.

Reducing Adverse Effects from UV Sunscreens by Zeolite Encapsulation: Comparison of Oxybenzone in Solution and in Zeolites

“…(40), is able to detect both double stranded breaks and single stranded breaks (SSB), as well as alkali‐labile sites; the alkaline treatment allows these other types of damage to be expressed. A modified version of the alkaline assay was used in this work and the method is described briefly below (41). Quantification was achieved by analyzing selected cells according to four parameters designed to represent the amount of DNA damage.…”

“…We also compared the ability of the supramolecular sunscreen to protect epidermal keratinocytes from UVR-induced damage. For these experiments the sunscreens were suspended in benzene and sandwiched between two quartz plates, according to the protocol of Reinhardt et al for determination of the protective capabilities of commercial sunscreens (41). The quartz plates were placed directly on top of the petri dishes containing the cells and the cells were irradiated through the plates with SSR for 10 min (ca.…”

Light-Induced Cytotoxicity and Genotoxicity of a Sunscreen Agent, 2-Phenylbenzimidazole in Salmonella typhimurium TA 102 and HaCaT Keratinocytes

“…Sunscreens are topical preparations that reduce the deleterious effects of UVR by absorption, reflection, or scattering [ 3 ]. Sunscreens can be divided into two categories: chemical and physical [ 7 ]. Chemical sunscreens provide protection by absorbing UV radiation while physical sunscreens prevent UV radiation from reaching the skin [ 1 , 3 ].…”

Octyl Methoxycinnamate Modulates Gene Expression and Prevents Cyclobutane Pyrimidine Dimer Formation but not Oxidative DNA Damage in UV-Exposed Human Cell Lines

“…It has been shown that some sunscreens change their spectral performance or may act as photooxidants via generation of free radicals and ROS upon UV exposure (Brezova et al , 2005; Gulston and Knowland, 1999). There are some reports of the protective effect of sunscreens against DNA damage formation in cell cultures (Reinhardt et al , 2003) and in the skin of volunteers (Al Mahroos et al , 2002). The decrease in the efficiency of sunscreens can be caused by different mechanisms: photoisomerization, photodecomposition, and interaction with the formulation or other sunscreen agents (Maier et al , 2001).…”