Molecular photoprotection of human keratinocytes in vitro in vitro by the naturally occurring mycosporine‐like amino acid palythine

摘要

Summary Background Solar ultraviolet radiation (UVR ) induces molecular and genetic changes in the skin, which result in skin cancer, photoageing and photosensitivity disorders. The use of sunscreens is advocated to prevent such photodamage; however, most formulations contain organic and inorganicUVR filters that are nonbiodegradable and can damage fragile marine ecosystems. Mycosporinelike amino acids (MAA s) are naturalUVR absorbing compounds that have evolved in marine species for protection against chronicUVR exposure in shallowwater habitats.Objectives To determine if palythine, a photostable modelMAA , could offer protection against a range ofUVR induced damage biomarkers that are important in skin cancer and photoageing.Methods HaCaT human keratinocytes were used to assess the photoprotective potential of palythine using a number of end points including cell viability,DNA damage (nonspecific, cyclobutane pyrimidine dimers and oxidatively generated damage), gene expression changes (linked to inflammation, photoageing and oxidative stress) and oxidative stress. The antioxidant mechanism was investigated using chemical quenching and Nrf2 pathway activation assays.Results Palythine offered statistically significant protection (P 0?05) against all end points tested even at extremely low concentrations (0?% w/v). Additionally, palythine was found to be a potent antioxidant, reducing oxidatively generated stress, even when added after exposure.Conclusions Palythine is an extremely effective multifunctional photoprotective moleculein vitro that has potential to be developed as a natural and biocompatible alternative to currently approvedUVR filters.