Vitamins and polyphenols in systemic photoprotection

Chapter

Abstract

  • The human organism depends on an adequate energy supply provided by major dietary components, protein, carbohydrates and lipids. However, minor constituents such as vitamins, minerals and specific fatty acids are required in a healthy diet as well. Secondary plant compounds are ingested with food and enter the systemic circulation. These are not essential in the strict sense of a vitamin, but some of these compounds exhibit distinct biological activities. Among them are terpenoids and polyphenols such as carotenoids, tocopherols, and fla-vonoids [1-3] which are known to be efficient antioxidant micronutrients. As the exterior barrier of the body, the skin is in direct contact with the environment. This organ is exposed to oxygen and light, conditions under which reactive oxygen species (ROS) are generated. Photooxidative stress is involved in processes of photoaging and photocarcinogen-esis, and plays a major role in the pathogenesis of photodermatoses [4]. As any other tissue, skin depends on an optimal supply of nutritive compounds. Skin benefits from dietary antioxidants capable of scavenging reactive intermediates generated under the condition of photooxidative stress [5-7]. Micronutrients may also act as UV absorbers, or modulate signaling pathways elicited upon UV exposure [8-10]. In plants, minor constituents play an important role in protection against excess light. Besides acting as accessory pigments, carotenoids are associated with photoprotection [11], being involved in the dissipation of excess light energy through the xanthophyll cycle, quenching excited triplet state molecules and singlet oxygen. Based on their structural features which determine their physicochemical properties, carot-enoids, flavonoids, and vitamins E and C are also suitable compounds for photoprotection in humans [6].
  • Digital Object Identifier (doi)

    International Standard Book Number (isbn) 10

  • 3540244433
  • International Standard Book Number (isbn) 13

  • 9783540244431
  • Start Page

  • 113
  • End Page

  • 121