TY - CHAP M1 - Book, Section TI - Antioxidants A1 - Baumann, Leslie Y1 - 2015 N1 - T2 - Cosmeceuticals and Cosmetic Ingredients AB - The skin has naturally occurring antioxidants that protect against the ravages of free radicals by reducing and neutralizing them (see Chapter 2, Basic Cosmetic Chemistry, for an explanation of free radicals). Antioxidative enzymes that naturally occur in the skin include superoxide dismutase, catalase, and glutathione peroxidase; nonenzymatic endogenous antioxidative molecules are α-tocopherol (vitamin E), ascorbic acid (vitamin C), glutathione, and ubiquinone (better known as coenzyme Q10 or CoQ10).1 However, as part of the natural aging process our defense mechanisms decrease. This leads to an imbalance and increased number of unchecked free radicals, which engender damage to DNA, cytoskeletal elements, cellular proteins, and cellular membranes. Moreover, many of these antioxidant defense mechanisms are inhibited by ultraviolet (UV) and visible light.2,3 Topical antioxidants are currently marketed for the prevention of aging and UV-mediated skin damage. The free radical theory of aging explains why antioxidants are thought to prevent wrinkles, but this theory does not justify the use of antioxidants to treat wrinkles that are already present. Several companies claim that their antioxidant-containing products “treat” wrinkles; however, this is an exaggeration. The only antioxidant that can improve wrinkles that have already been formed is ascorbic acid, through its effects on collagen synthesis.4 SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/19 UR - dermatology.mhmedical.com/content.aspx?aid=1174542502 ER -