title: Ultraviolet light induced alteration to the skin.
abstract: Solar light is the primary source of UV radiation for all living systems. UV photons can mediate damage through two different mechanisms, either by direct absorption of UV via cellular chromophores, resulting in excited states formation and subsequent chemical reaction, or by phosensitization mechanisms, where the UV light is absorbed by endogenous (or exogenous) sensitizers that are excited and their further reactions lead to formation of reactive oxygen species (ROS). These highly reactive species can interact with cellular macromolecules such as DNA, proteins, fatty acids and saccharides causing oxidative damage. Direct and indirect injuries result in a number of harmful effects such as disrupted cell metabolism, morphological and ultrastructural changes, attack on the regulation pathways and, alterations in the differentiation, proliferation and apoptosis of skin cells. Processes like these can lead to erythema, sunburn, inflammation, immunosuppression, photoaging, gene mutation, and development of cutaneous malignancies. The endogenous and exogenous mechanisms of skin photoprotection are discussed.
authors.affiliation: Institute of Medical Chemistry and Biochemistry, Faculty of Medicine, Palacký University, Hnevotínská 3, Olomouc, Czech Republic. alf.svoboda@seznam.cz
authors.forename: Alena
authors.initials: A
authors.lastname: Svobodova
authors.forename: Daniela
authors.initials: D
authors.lastname: Walterova
authors.forename: Jitka
authors.initials: J
authors.lastname: Vostalova
mesh_terms: D006801:Humans; D018462:Photobiology; D011832:Radiation Injuries / Q000517:prevention & control; D017382:Reactive Oxygen Species / Q000378:metabolism; D012867:Skin / Q000378:metabolism / Q000528:radiation effects*; D013473:Sunscreening Agents / Q000008:administration & dosage; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D017382:Reactive Oxygen Species; D013473:Sunscreening Agents