Title: Antioxidants for vitiligo and photoprotection: new insights and possible therapeutic implications.
Introduction: It is known that oxidative stress is of main importance in the pathogenesis of vitiligo and in the cutaneous photo-damage. Reactive oxygen species (ROS) can start a pathogenetic cascade that leads to photo-carcinogenesis and photo-aging. Indeed, ROS induce DNA oxidative damage (i.e., strands breaks, nucleic acids oxidations, mutagenic lesions), proteins and lipid peroxidation and dermal accumulation. An imbalance in ROS scavenging systems have been reported in vitiligo patients, and hydrogen peroxide excess is known to induce melanocytes damage. Hence, the use of antioxidants (AOs) in dermatology, both endogenous and exogenous, have been investigated during the last two decades.
Aims & Scope: To evaluate the current knowledge about the use of AOs for increase photo-protection and vitiligo prevention and/or treatment.
Material and Methods: Antioxidants can be administered both topically and orally: the pros and cons of each one of these ways is discussed. 13 AOs have been chosen on the basis of their beneficial effects for photo-protection and vitiligo, and described in details. For each AO agent, the most recent and important studies have been reported. The Exogenous AOs molecules here discussed include: vitamin C, vitamin E, vitamin A, 4 flavoinoids (i.e., resveratrol, quercetin, tea polyphenols and soy isoflavones) Polypodium leucotomos extract, curcumin, capsaicin. Endogenous AOs include: polyunsatured fatty acids, glutathione, melatonin.
Results: Many recent studies on AOs show promising results, in both topical and oral administration of various antioxidants agents, alone or in combination with other AOs, minerals or aminoacids, and with phototherapy (i.e., narrow band UVB or PUVA). However, large part of the last decades’ studies have used in vitro models or animal models (especially mice), while few investigation have involved human beings.
Comments: Further investigations on human model, including randomized double-blind trials on large population groups, are necessary to obtain statistically significant data and to test different treatment modalities (oral vs topical, alone vs combined) of the various AOs molecules.
2 questions with 3 multiple choice:
1) Which of the following AOs have shown to protect against several cancers, beside skin cancer?
A. Vitamin C
2) Which of the following AOs combination has been recently demonstrated toimprove the resistance of cultured cells to oxidative stress, in vitro?
A. Resveratol and capsaicin
B. Curcumin snd capsaicin
C. Curcumin and Polipodyum leucotmos exract
This PPT is loaded as student material "as is", from the VRF Vitiligo Master Class Barcelona November 2011; VRF does not endorse or otherwise approve it.