of the Faculty of Medicine in Niš 2014

Skin aging is a dynamic process that occurs due to chronological and photo-aging caused by the influence of external factors, especially ultraviolet-UV radiation. Cumulative oxidative stress, formation of free radicals and their adverse effects on biological systems in the skin cells is a common mechanism of both skin aging processes. The formed reactive oxygen species-ROS can lead to the oxidation of cell`s building molecules. Lipid peroxidation, membrane protein damage and DNA mutation may lead to many structural, functional and aesthetic changes in the skin and can also initiate development of many diseases. One of the skin defense mechanisms is antioxidant defense where enzymes and other antioxidant substances react directly with ROS, preventing them from reaching their biological target. Antioxidant substances have the ability to bind free radicals, caused by oxidative stress, and may have significance in prevention and/or therapy of various skin diseases, as well as in slowing the skin aging process. Topical application of antioxidants, such as vitamin C and E, coenzyme Q10 and polyphenolic compounds may provide the strengthening of the skin endogenous protection system and protection from harmful effects of ROS and oxidative damage to the skin. This article outlines the impact of oxidative stress on the chronological and photo-aging, its mechanism of action, the changes that occur on/in the skin during the aging process. Substances with antioxidant characteristics, which can be used in the prevention of chronological and/or treatment of photo-aging of the skin are shown.