Chronological ageing and photoageing of the fibroblasts and the dermal connective tissue

In recent years, the exposure of human skin to environmental and artificial UV irradiation has increased dramatically. This is due not only to increas ed solar UV irradiation as a consequence of stratospheric ozone depletion, but also to inappropriate social behaviour with the use of tanning salons s till being very popular in the public view. Besides this, leisure activitie s and a lifestyle that often includes travel to equatorial regions add to t he individual annual UV load. In addition to the common long-term detriment al effects such as immunosuppression and skin cancer, the photo-oxidative d amage due to energy absorption of UV photons in an oxygenized environment l eads to quantitative and qualitative alterations of cells and structural ma cromolecules of the dermal connective tissue responsible for tensile streng th, resilience and stability of the skin. The clinical manifestations of UV /reactive oxygen species (ROS)-induced disturbances result in photoaged ski n with wrinkle formation, laxity, leathery appearance as well as fragility, impaired wound healing capacities and higher vulnerability. Strategies to prevent or at least minimize ROS-induced photo-ageing and intrinsic ageing of the skin necessarily include protection against UV irradiation and antio xidant homeostasis.