Molecular approaches to prevent UV-induced premature skin aging: focus on phytochemicals as photo-protectants

Abstract

Chronic exposure to ultraviolet radiation (UVR) leads to premature aging of the skin, with external manifestations of unsightly scars and internal molecular dysregulations that significantly reduce the protective function of the skin and increase the risk of cancer development. Photoprotection through daily application of sunscreen product is widely recommended to avoid UV-induced skin photodamage and to minimaze the risk for dermal malignancies. However, the environmental hazard that is a consequence of the use of traditional sunscreen products drives the increased interest in the investigation of alternative UVR blockers. Due to their structural diversity, modulation of multiple molecular mechanisms, and favorable safety profile, natural plant-derived compounds have become attractive candidates for skin photoaging prevention. This review summarizes the critical aspects of skin photoaging, from its pathological characteristics and current photoprotective options to the specific molecular players that emerge as therapeutic targets. Special emphasis has been placed on phytochemicals targeting the molecular hallmarks of UV-induced skin aging. The potential of plant molecules to control oxidative stress, inflammation, photo-senescence, DNA damage, extracellular matrix components degradation, and to manage different types of UV-trigerred cell death has been highlighted. Summarizing the molecular signalling pathways responsible for the photoprotective action of plant-derived molecules may provide meaningful outlook for development of new effective therapeutics options for prevention of skin photoaging.