The International School of Vitiligo & Pigmentary Disorders

Barcelona, 2-5 November 2011

Antioxidants for

vitiligo and

photoprotection:

new insights and

possible

therapeutic

implications.Linda Tognetti, MD

Division of Clinical, Preventive and Oncologic Dermatology Department of Critical Care Medicine and Surgery

University of Florence (Italy)

‘‘

THE ROLE OF OXIDATIVE STRESS IN CUTANEOUS PHOTO-DAMAGE

UV light

Photochemic reaction in the skin

Proteins and lipids peroxidation

Extracellular accumulation

PHOTO-CARCINOGENESISMelanoma; BCC and SCC

PHOTO-AGINGwrinkles, dryness, telangiectasia,

pigmentary abnormalities

CROMOPHORES

1O2 singlet oxygen> Urocanic acid

> DNA

SKIN filaggrin breakdown

(high concentrations superficially in the epidermis)UV

absorption

Cell membrane damage

Reactive oxygen species (ROS)

changes between adjacent pyrimidine bases

φ photon

Strand breaks + nucleic acids oxidation

Mutagenic lesions

Masaki H. Role of antioxidants in the skin: anti-aging effects. J Dermatol Sci 2010;58(2):85-90.

Inflammation

Dermal matrix alteration

Sander CS et al. Oxidative stress in malignant melanoma and non-melanoma skin cancer. Br J Dermatol 2003;148(5):913-22.

THE ROLE OF OXIDATIVE STRESS IN THE PATHOGENESIS OF VITILIGO

Significantly higher

levels of indicators of

oxidative stress:

malondialdehyde

and xanthine oxidase

Significantly lower levels of: - vitamins C - vitamin E- superoxidedismutase- glutathione peroxidase- catalase- total antioxidant ativity

ROS cause lipid peroxidation of cellular membrane of melanocytes

Imbalance of ROS scavenging

system in vitiligo melanocytes

Oxidative damage is the initial pathogenic event in melanocyte degeneration

H2O2 transfered from

keratinocytes to

melanocytes

ROS alter melanocytes’ specific factors to produce neo-antigens amplify antigen presentation

promote autoimmune destruction of melanocytes

Haider N et al. Oxidative Stress and Antioxidant Status in Vitiligo Patients.Dhaka Univ J Pharm Sci 2010; 9(2): 103-8. Pelle E et al. Keratinocytes act as a source of reactive oxygen species by transferring hydrogen peroxide to melanocytes. J Invest Dermatol 2005;124:793–797.

Sravani PV et al. Determination of oxidative stress in vitiligo by measuring superoxide dismutase and catalase levels in vitiliginous and non-vitiliginous skin. Ind J Dermatol Venereol Leprol 2009;75:268–271. Koca R et al. Oxidant-antioxidant enzymes and lipid peroxidation in generalized vitiligo. Clin Exp Dermatol 2004; 29(4): 406-9.

Khan R et al. Circulatory levels of antioxidants and lipid peroxidation in Indian patients with generalized and localized vitiligo. Arch Dermatol Res 2009; 301(10):731-7Namazi MR. Neurogenic dysregulation, oxidative stress, autoimmunity, and melanocytorrhagy in vitiligo: Can they be interconnected? Pigment Cell Res 2007;20:360-3.

in the skin and blood of vitiligo patients, compared with controls

Increased oxidative

stress

High metabolic demands

Depletion of antioxidants reserves

Physiologic antioxidant systems

are insufficient

SKINOXIDATIVE DAMAGE

Environmental factors (smoking, pollution)

ANTIOXIDANTS ADMINISTRATIO

N: It may prevent

and/or limit photo-damage

and vitiligo pathogenesis?

Masaki H. Role of antioxidants in the skin: anti-aging effects. J Dermatol Sci 2010;58(2):85-90.

Gonzalez S et al. A New Generation of Oral Photoprotectors. The Open Dermatology Journal 2011; 5:6-14.

ORALDiet,

supplementation

TOPICALSunscreen

creams

TOPICAL ANTIOXIDANTS

Gonzalez S et al. Current Trends in Photoprotection - A New Generation of Oral Photoprotectors. Open Dermat J 2011; 5:6-14.

Wang SQ et al. Photoprotection: a review of the current and future technologies. Dermatol Ther 2010;23(1):31-47.

TOPICAL AOs are a supplement to the physiological

antioxidant protection present in the skin.

They augment photoprotection provided by

sunscreens lotions/creams.

Direct application to the skin has the advantage of targeting a specific

skin

area needing photoprotection.

Once penetrated through the stratum corneum, they may remain

active for

several days.

Topical AOs exert their effect inside the cells: by regenerating

each other, they provide an ontioxidants’ reservoir. Pinnell SR. Cutaneous photodamage, oxidative stress, and topical antioxidant protection. J Am Acad Dermatol 2003;48:1-19.

ORAL ANTIOXIDANTS

Epstein HA. The effect of diet and nutrition on the skin. Prime 2011;1:4 : 46-51.

Physiologic processes related to absorption, solubility and transport of oral AOs are

not

fully known, but they seem to limit the quote of oral OAs that can be delivered into

the skin.

An AO molecule is more stable when incorporated by nutrition in the skin, where it

accumulates in a mixture with different AOs molecules, compared with single

topically

applied AO.

Oral AOs increase the basal threshold of systemic AOs,

actively collaborating in refreshing skin natural AO systems.

Toghether with Topical AOs, Oral AOs can prevent

photoaging and photocarcinogenesis, in both animal

and human models.

Oral AOs administration helps preventing skin alterations,

(e.g., uneven skin tone and atopic dermatitis) and correlates

with a lower incidence of wrinkles.Gonzalez S, et al. Current Trends in Photoprotection - A New Generation of Oral Photoprotectors. Open Dermatol Journ 2011; 5:6-14.

Namazi MR, et al. Vitiligo and diet: a theoretical molecular approach with practical implications. Indian J Dermatol Venereol Leprol 2009;75(2):116-8.

VITAMIN C

VITAMIN E

VITAMIN A

RESVERATROL

QUERCETIN

TEA POLYPHENOLS

SOY ISOFLAVONES

Polypodium leucotomos extract

POLYUNSATURED FATTY ACIDS

CURCUMIN

CAPSAICIN

GLUTATHIONE

MELATONIN

13 Antioxidants

Flavonoids

VITAMIN C

Topical administration of L-ascorbate and its derivates (with greater

cutaneous penetration) augments photo-protection (sunscreen

component),

improves epidermal barrier function and provides anti-aging effects

(moisturizing creams component).

Oral combination of vitamins C and E in high doses provide protection

against UV-induced erythema.

Ascorbic acid plasma levels are often lowered in patients with vitiligo.

Oral administration of vit C, in association with vit E/ vit A/ vit B12/

folic acid +/- broadband UVB, has been followed by definite

repigmentation without side effects in vitiligo patients.

Don P et al.Treatment of vitiligo with broadband ultraviolet B and vitamins. Int J Dermatol. 2006;45(1):63-5.

Montes LF, et al. Folic acid and vitamin B12 in vitiligo: a nutritional approach. Cutis 1992;50(1):39-42.

Darr D et al. Effectiveness of antioxidants (vitamin C and E) with and without sunscreens as topical photoprotectants. Acta Derm Venereol 1996;76(4):264-8.

SOURCES :papayastrawberryorangekalelemonmelonauliflowergarlicgrapefruitraspberrykiwimandarinpassion fruitspinachlimemangoblackberrypotatomeloncranberrytomatoblueberrypineapple

Eberlein-Konig B et al. Protective effect against sunburn of combined systemic ascorbic acid (vitamin C) and d-alpha-tocopherol (vitamin E). J Am Acad Dermatol 1998;38:45-8.

Vitamin C or L-ascorbic acid is the predominant

AO in

the skin and it is an essential cofactor for collagen

synthesis.

Vitamin E exists in 8 forms, 4 tocopherols and 4 tocotrienols,

being α-tocopherol the most represented in humans.

Topical application of α-tocopherol reduces photo-aging

and

photo-carcinogenesis, and prevents UV-induced erythema,

lipid

peroxidation and immunosuppression.

Oral administration of vit E combined with vit C and/or vit A

demonstrated to increase protection against UV-induced

damage.

Oral 3 months-therapy with α-tocopherol plus ubiquinone,

selenomethionine, methionine stopped the progression of

vitiligo

and induced repigmentation of the most recent lesions.

Oral vit E has shown to increase narrow band-UVB

effectiveness

in vitiligo patients.

Lin JY et al. UV photoprotection by combination topical antioxidants vitamin C and vitamin E. J Am Acad Dermatol 2003: 48: 866–874.

Elgoweini M et al. Response of vitiligo to narrowband ultraviolet B and oral antioxidants. J Clin Pharmacol 2009;49(7):852-5.

Yuen KS, et al. Alpha-tocopherol, an inhibitor of epidermal lipid peroxidation, prevents ultraviolet radiation from suppressing the skin immune system. Photochem Photobiol 1997;65:587-92.

Picardo M et al. Antioxidant treatment in vitiligo? Pigment Cell Res 1997;10:360.  

SOURCES :wheat germ oilsunflower oilsafflower oilnuts, nut oilsgreen leafy vegetablestomato productspumpkinsweet potato rockfishmangoesasparagusbroccolipapayasavocados

VITAMIN E

VITAMIN A

Jalel A et al. Vitiligo treatment with vitamins, minerals and polyphenol supplementation. Indian J Dermatol 2009;54(4):357-60.

Oral supplementation with vit A plus vit C and vit E, and

minerals

promoted vitiligo lesion repigmentation in the mice settings.

SOURCES : Liver (beef, pork, chicken, turkey, fish) carrot broccoli leaf sweet potato butter kale spinach pumpkin collard greens cheddar cheese cantaloupe melon egg apricot papaya mango pea broccoli milk

Vitamin A includes retinol and carotenoids (α/β/γ-

carotene,

lycopene and the xanthophylls lutein and zeaxanthin).

Daily oral β-carotene (30mg) can prevent and repair

photoaging

and increases synthesis of procollagen type I.

Topical β-carotene (2mg/cm2) provides protection against ROS

in the

human skin exposed to infra-red radiation.

Vit A is fat-soluble and can be stored in keratinocytes as retinyl esters.

Cho S et al. Differential effects of low-dose and high-dose beta-carotene supplementation on the signs of photoaging and type I procollagen gene expression in human skin in vivo. Dermatology. 2010;221:160-71.

Darvin ME et al. Topical beta-carotene protects against infra-red-light-induced free radicals. Exp Dermatol 2011;20:125-9.

Carotenoids are useful to protect against UV-induced damage:

Lycopene concentration in skin correlates significantly with

roughness.

Camera E et al. Astaxanthin, canthaxanthin and beta-carotene differently affect UVA-induced oxidative damage and expression of oxidative stress-responsive enzymes. Exp Dermatol 2009; 18:222–231.

QUERCETIN

SOURCES :applesonions (++red onion)red grapescitrus fruittomatobroccolileafy green vegetablesraspberrywhortleberrylingonberrycranberrychokeberryrowanberrycaperslovagerootslegumes

Quercetin is a very potent AO,

member

of the flavonoids family. Topical quercetin has successfully inhibited UVB-

induced skin damage in rodent models.

Casagrande R et al. Protective effect of topical formulations containing quercetin against UVB-induced oxidative stress in hairless mice. J Photochem Photobiol B 2006; 84(1): 21-7.

Topical application of the quercetin aglycone has been shown

to

prevent UVC-induced liposome peroxidation, UVB-induced

myeloperoxidase activity and glutathione depletion.

Vicentini FT et al. Quercetin in w/o microemulsion: in vitro and in vivo skin penetration and efficacy against UVB-induced skin damages evaluated in vivo. Eur J Pharm Biopharm 2008; 69(3): 948-57.

Fahlman BM et al. UVA and UVB radiation-induced oxidation products of quercetin. J Photochem Photobiol B. 2009; 97: 123-31.

In vitro studies demonstrated that quercetin can efficiently

contrast

keratinocytes oxidative damage induced by H2O2 exposure.

Wang X, et al.Quercetin in combating H2O2 induced early cell apoptosis and mitochondrial damage to normal human keratinocytes Chin Med J 2010;123(5):532-536

GREEN TEA POLYPHENOLS

Green tea polyphenols definition is used to refer to several potent

antioxidants

that appear in green tea leaves.

The most abundant (60-80%) polyphenols contained in green tea leaves

are

cathechins: epicatechin

epicatechin-3-gallate

epigallocatechin

epigallocatechin-3-gallate (EGCG) most important molecule

As antioxidant, cathehins are more potent than vitamins C and E.

Cathechins are able to regenerate oxidized vitamin E.

Harbowy ME et al. Tea chemistry. Crit Rev Plant Sci 1997;16:415-80.

Jeon HY et al. Effects of oral epigallocatechin gallate supplementation on the minimal erythema dose and UV-induced skin damage. Skin Pharmacol Physiol 22; 2009:137–141.

EGCG has photo-protective, anti-inflammatory,

anti-carcinogenic effects (promotes rapid repair of UVB-

induced DNA damage) and can inhibit collagenase activity.

Several studies assessed that oral administration of EGCG significantly

increases

the minimal erythema dose to UV, prevents disruption of the epidermal

barrier

function, improves microcirculation and modulates skin properties of

women.

Topical application of EGCG inhibits carcinogenesis and selectively

increases

apoptosis in UVB-induced skin tumors, in both animal and human model.

Oral supplementation of green tea decoction in association with vit A/E/C

and

minerals (selenium, zinc) has promoted vitiligo lesions repigmentation in

mice.

Katiyar SK. Green tea prevents non-melanoma skin cancer by enhancing DNA repair. Arch Biochem Biophys. 2011; 508: 152-158.

Jalel A et al. Vitiligo treatment with vitamins, minerals and polyphenol supplementation. Indian J Dermatol 2009;54(4):357-60.

Lu YP et al. Topical applications of caffeine or (-)-epigallocatechin gallate (EGCG) inhibit carcinogenesis and selectively increase apoptosis in UVB-induced skin tumors in mice. Proc Natl Acad Sci U S A 2002: 99: 12455–60. Camouse MM et al. Topical application of green and white tea extracts provides protection from solar-simulated ultraviolet light in human skin. Exp Dermatol. 2009; 18: 522-526.

Heinrich U, et al. Green tea polyphenols provide photoprotection, increase microcirculation, and modulate skin properties of women. J Nutr 2011; 141: 1202-8.

GREEN TEA POLYPHENOLS

TEA POLYPHENOLS

QUERCETIN VITAMIN C

Jeong Y-M et al. Cytoprotective Effect of Green Tea Extract and Quercetin against Hydrogen Peroxide-Induced Oxidative Stress. Arch Pharm Res 2005; 28(11):1251-56.

Green tea extract, quercetin and vitamin C have

demonstrated strong cytoprotective effects on H202

treated Mel-Ab melanocytes (immortalized mouse

melanocyte cell line), preventing H202-induced cell

death.

The triple combination green tea

extract/quercetin/folic acid prevented the cellular

damage induced by H202 in a synergistic manner.

This suggests that effective combinations of AOs

may be of importance, and that co-treatment with

AOs offers a possible means of treating vitiligo.

Jeong Y-M et al. Cytoprotective Effect of Green Tea Extract and Quercetin against Hydrogen Peroxide-Induced Oxidative Stress. Arch Pharm Res 2005; 28(11):1251-56.

RESVERATROL

Topical adsorbption of resveratrol has been investigated,

and its topical use on hairless mice before UVB irradiation

decreased erythema, ROS production and inflammation.

Resveratrol is a polyphenolic phytoalexin.

SOURCES :

Grapes/wines

(red,rose,white,

pinot noir)

peanuts

mulberries

blueberries

apples

cocoa powder

baking chocolate

dark chocolate

Its benifical effects (anti-oxidant, anti-inflammatory, anti-

cancer,

blood sugar-lowering) are currently a topic of numerous animal

and

human studies.

Oral resveratrol can prevent UV-induced tumorigenesis,

increases

cell survival and contrast cutaneous inflammatory disorders.

Nichols JA et al. Skin photoprotection by natural polyphenols: anti-inflammatory, antioxidant and DNA repair mechanisms. Arch Dermatol Res 2010; 302(2): 71-83.

Aziz MH et al. Longley BJ, Ahmad N. Chemoprevention of skin cancer by grape constituent resveratrol: relevance to human disease? Faseb J 2005; 19(9): 1193-5.

Ndiaye M et al. Ahmad N. The grape antioxidant resveratrol for skin disorders: promise, prospects, and challenges. Arch Biochem Biophys 2011;508(2):164-70. Hung CF et al. Delivery of resveratrol, a red wine polyphenol, from solutions and hydrogels via the skin. Cancer Prev Res 2010;3(2):170-8.

SOY ISOFLAVONES Soybeans and their associated food products are a rich source of

flavonoids called isoflavones, the most abundant being genistein.

Topical genistein reduces erythema and histologic inflammation induced by PUVA in

mice.

Oral genistein decreases UVB-induced skin photoaging, carcinogenesis,

inflammation and immunosuppression in a rodent model.

Wei H et al. Isoflavone genistein: photoprotection and clinical implications in dermatology. J Nutr 2003; 133(11s1): 3811S-3819S.

SOURCES :

Soy

red clover

ginkgo biloba

Genistein has collagen-stimulating effects, by increasing collagen (COL1A2) gene expression.

Greenwel P et al. Tyrosine dephosphorylation of nuclear proteins mimics transforming growth factor beta-1 stimulation of alpha-2 (I) collagen gene expression. Mol Cell Biol 1995;15:6813-9.

Shyong EQ et al. Effects of the isoflavone 4 ’, 5,7-trihydroxyisoflavone (genistein) on psoralen plus ultraviolet A radiation (PUVA)-inducedphotodamage. Carcinogenesis 2002; 23:317-21.

Widyarini S, et al. Isoflavonoid compounds from red clover (Trifolium pratense) protect from inflammation and immune suppression induced by UV radiation. Photochem Photobiol 2001: 74: 465–470.

In animal studies, oral soy or genistein protected against several

cancers including bladder, breast, colon, liver, lung, prostate and skin.

Barnes S. Effect of genistein on in vitro and in vivo models of cancer. J Nutr 1995;125:S777-83.

A recent study has reported an association between daily ingestion of Ginko biloba

with a

significant improvement in total VASI (Vitiligo Area Scoring Index) and VETF (Vitiligo

European Task Force) staging in vitiligo patients.

Szczurko O. Ginkgo biloba for the treatment of vitilgo vulgaris: an open label pilot clinical trial. BMC Complement Altern Med 2011;11:21.

CURCUMIN

Curcumin, a low-molecular-weight polyphenol derived

from

Curcuma longa, is an active ingredient in the spice

tumeric,

to which curcumin gives the yellow color.

Curcumin has anti-oxidant (induction of glutathione S-

transferase enzymes), anti-proliferative,

anti-inflammatory (inhibition on cytokines and

prostaglandines synthesis),

antiviral, antibacterial and antifungal properties.

It reduces wound-healing time, improves collagen

deposition

and increases fibroblast and vascular density in wounds.

Rowe DL, et al. Modulation of the BRCA1 Protein and Induction of Apoptosis in Triple Negative Breast Cancer Cell Lines by the Polyphenolic Compound Curcumin. Breast Cancer: Basic and Clinical Research 2009; 3: 61–75.

Koeberte A, et al Curcumin blocks prostaglandin E2 biosynthesis through direct inhibition of the microsomal prostaglandin E2 synthase-1. Molecul Cancer Therapeut 2009; 8:2348-2355

Potentially, curcumin could be employed in treatment

of different skin diseases.

Phototoxic dermatitis Melanoma Vitiligo Psoriasis Morphea Chronic inflammatory diseases Primary cutaneous T-cell

lymphoma NM skin cancer Cosmetics

Cho JW et al.. Curcumin attenuates the expression of IL-1beta, IL-6, and TNF-alpha as well as cyclin E in TNF-alpha-treated HaCaT cells; NF-kappaB and MAPKs as potential upstream targets. Int J Mol Med 2007; 19: 469-474.

Phototoxic dermatitis

Ishizaki C et al. Enhancing effect of ultraviolet A on ornithine decarboxylase induction and dermatitis evoked by 12-o-tetradecanoylphorbol-13-acetate and its inhibition by curcumin in mouse skin.Dermatol 1996; 193: 311-317.

Melanoma

Curcumin at higher doses induces apoptosis in relatively resistant malignant

human melanoma cell lines, and its combination with tamoxifen provides a

non-toxic option for combinatorial chemotherapy.

Chatterjee S et al. Chemo-resistant melanoma sensitized by tamoxifen to low dose Curcumin treatment through induction of apoptosis and autophagy. Cancer Biol Ther 2011; 11: 216-228.

Vitiligo

A recent clinical trial has demonstrated that the association with topical

tetrahydrocurcuminoid cream increases the effectiveness of targeted

narrowband UVB phototherapy for induction of repigmentation in vitiligo

patients.

Asawanonda P, Klahan S. Tetrahydrocurcuminoid cream plus targeted narrowband UVB phototherapy for vitiligo: a preliminary randomized controlled study. Photomed Laser Surg 2010; 28: 679-684.

It has been showed that topical pretreatment with curcumin

significantly inhibited the pro-inflammatory effect of topically-applied tumor

promoter 12-o-tetradecanoylphorbol-13-acetate (TPA) in combination with

UVA .

Becatti M, Prignano F, et al. The involvment of Smac/DIABLO, p53, NF-kB, and MAPK pathways in apoptosis of keratinocytes from perilesional vitiligo skin: Protective effects of curcumin and capsaicin. Antiox Redox Signal 2010;13(1309-1321.

Vitiligo

• A recent in vitro study has evaluated the protective effects of

combinatorial therapy with curcumin and capsaicin

supplementation in cultured cells from lesional, perilesional and

healthy skin of selected vitiligo patients.

• Total antioxidant capacity and mitochondrial membran

depolarization has markers of scavenging activity and

mitochondrial integrity have been considered.

• The supplement of curcumin and capsaicin can improve the

resistance of cultured cells to oxidative stress.

CAPSAICIN

Capsaicin is a natural irritant of the vanilloid family, and represents

the main capsaicinoid of chilli peppers and other capsicum

preparations (chilli, cayenne pepper, red pepper) obtained

from the fruits of the Solanaceae plants, of the genus Capsicum.

Capsaicin is a potent anti-inflammatory agent which has been used for :

pain and itch relief, because of its desensitization property (it produces a

long-lasting refractory period after the initial excitation of sensory neurons);

cancer prevention; cardiovascular diseases; weight reduction.

High antioxidant and anti-apoptotic potential of capsaicin have been recently

described.

Pre-treatment with capsaicin inhibits keratinocytes apoptosis in peri-lesional

vitiligo skin, increases cellular total antioxidant capacity, contrasts ROS

generation and

lipid peroxidation and improves mitochondrial activity and cell metabolism.

Becatti M et al. The involvement of Smac/DIABLO, p53, NF-kB, and MAPK pathways in apoptosis of keratinocytes form perilesional vitiligo skin: protective effects of curcumin and capsaicin. Antioxid Redox Signal 2010;13(9):1309-21.

Oyagbemi AA et al. Capsaicin: A novel chemopreventive molecule and its underlying molecular mechanisms of action. Indian J Cancer 2010;47(1):53-8

POLIPODYUM LEUCOTOMOS EXTRACT P. leucotomos (PL) extract is obtained from the fern P. leucotomos.

Middelkamp-Hup MA et al. Orally administered Polypodium leucotomos extract decreases psoralen-UVA-induced phototoxicity, pigmentation, and damage of human skin. J. Am. Acad. Dermatol. 2004; 50(1): 41-49.

PL prevents oxidative DNA damage by accelerateing repair of thymine

dimers and

inhibiting trans-urocanic acid photoinduced isomerization and inactivation.

Capote R et al. Polypodium leucotomos extract inhibits trans-urocanic acid photoisomerization and photodecomposition. J Photochem Photobiol B 2006; 82(3): 173-9.

PL can potentiate the endogenous antioxidant response and inhibits photo-

immunosupression.

Brieva A, et al. Immunomodulatory properties of an hydrophilic extract of Polypodium leucotomos. Inflammopharmacol 2002;9:361-71.

Topical application of PL showed to inhibit UVB- and PUVA

therapy-

induced erythema, in vivo, and to contrast photocarinogenesis.

Gonzalez S et al. Topical or oral administration with an extract of Polypodium leucotomos prevents acute sunburn and psolaren-inducedphototoxic reactions as well as depletion of Langerhans cells in human skin. Photodermatol. Photoimmunol Photomed 1997; 13: 50-60.

Oral administration provides photoprotection and significantly decreases

Langerhans cells depletion.

Ω3-POLYUNSATURED FATTY ACIDS Ω -3 polyunsatured fatty acids (PFA) are well-documented

antioxidants

and inhibitors of pro-inflammatory cytokines (e.g.,TNF-α) and free

radicals.

Ω-3 PFA in the presence of AOs supplement appears to exert

protection

against auto-immunity by enhancing antioxidant enzymes.

The enrichment of cell membranes with Ω-3 PFA has been reported

to

increase the glutathione (GSH) peroxidase activity.

High doses of Ω-3 PFA have been shown to decrease UVB-induced

erythema and flogsis.

Moreover, Ω-3 PFA seem to favorably influence the vulnerability and

outcome in depressive disorders, that affect many patients with

vitiligo.

The diet of vitiligo patients should include large use of Ω-3 PFA.

Joulain C . Increased glutathione peroxidase activity in human blood mononuclear cells upon in vitro incubation with n-3 fatty acids. Biochem Pharmacol 1994;47:1315-23.

Namazi MR et al. Vitiligo and diet: A theoretical molecular approach with practical implications. Indian J Dermatol Venereol Leprol 2009;75:116-8

Logan AC. Omega-3 fatty acids and major depression: A primer for the mental health professional. Lipids Health Dis 2004;3:25.

Fernandez G. Dietary lipids and risk of autoimmune disease. Clin Immunol Immunopathol 1994;72:193-7.

Rhodes LE et al. Dietary fishoil supplementation in humans reduces UVB-erythemal sensitivity but increases epidermal lipid peroxidation. J Invest Dermatol 1994; 103(2): 151-4.

SOURCES:cold water oily fish (salmon, herring, mackerel, anchovies, sardines)fish oil,flaxseeds,nuts, eggs,Brussel sprouts,black raspberry,cowberry

GLUTATHIONE Glutathione (GSH) is a tripeptide ( γ-L-glutamyl-L-cysteinyl-glycine)

and represents one of the major contributor to the functional

vitality and morphological integrity of cells, where it controls redox-equilibrium.

GSH provides efficient protection against UVB-rays damages, by

inactivating different

ROS and regulating several genes involved in DNA repair and cell cycle regulation. Suprabasal keratinocytes employ high GSH quotes to absorb and neutralize UVB radiation, and

paracrine GSH secretion might mediate basal cells protection.

GSH paracrine stimulation of basal keratinocytes decreases the rate of cyclobutane

dimers formation

and p53-positive cells.

Schäfer M et al. Nrf2 establishes a glutathione-mediated gradient of UVB cytoprotection in the epidermis. Genes Dev 2010; 24:1045-58.

Zhu M et al. Molecular mechanisms for UV-B irradiation-induced glutathione depletion in cultured human keratinocytes. Photochem Photobiol 2004; 80: 191-6.

A severe GSH depletion has been documented inside keratinocytes after UV

irradiation. The rationale of GSH supplementation is providing intrinsic wide-spectrum photo

protection,

cancer prevention and anti-aging effect.

Steenvoorden DP et al.The use of endogenous antioxidants to improve photoprotection. J Photochem Photobiol 1997; 41:1-10.

Sekhar RV et al. Deficient synthesis of glutathione underlies oxidative stress in aging and can be corrected by dietary cysteine and glycine supplementation. Am J Clin Nutr 2011

Various studies assessed low levels of glutathione peroxidase activity

and total antioxidant status in vitiligo patients with or without

diabetes and thyreopathy.

It has been demonstrated that this depletion in antioxidant processes is involved

in vitiligo pathogenesis.

Reduced erythrocytic or systemic GSH levels constitute a distinctive feature in

vitiligo

patients regardless of disease activity.

Anti-oxidant supplementation with GSH-precursor may be helpful in vitiligo

treatment.

Consuming high protein foods, rich in sulphur-containing amino acids can help

boost

glutathione levels.

Shin JW et al. Erythrocyte malondialdehyde and glutathione levels in vitiligo patients. Ann Dermatol 2010;22(3):279-83.

Jalel A, et al. Study of total antioxidant status and glutathione peroxidase activity in Tunisian vitiligo patients. Indian J Dermatol 2009;54(1):13-6.

Khan R et al. Circulatory levels of antioxidants and lipid peroxidation in Indian patients with generalized and localized vitiligo. Arch Dermatol Res 2009; 301(10):731-7

Lu SC. Regulation of glutathione synthesis. Mol Aspects Med 2009; 30: 42-59.

Haider N et al. Oxidative Stress and Antioxidant Status in Vitiligo Patients.Dhaka Univ J Pharm Sci 2010; 9(2): 103-8.

GLUTATHIONE

MELATONIN Melatonin (MN) is one of the most ancient and phylogenetically

conserved hormones, occurring in unicellular, plants and animals.

MN is a potent scavenger of oxygen (OH, O2−), and NO radicals:

it has an higher reduction potential than Vitamin C

It is fivefold better than glutathione at neutralizing hydroxyl radicals, and twofold more

effective

than vitamin E at inactivating peroxyl radicals

Tan DX et al.Chemical and physical properties and potential mechanisms: melatonin as a broad spectrum antioxidant and free radical scavenger. Curr Top Med Chem 2002; 2: 181-97.

Direct antioxidant

MN enhances gene expression of the main antioxidants enzymes:

superoxide dismutase (SOD), catalase, glutathione peroxidase Indirect antioxidant

MN contributes to the preservation of the epidermal barrier

contrasts solar radiation and other physico-chemical stressors

activates the pigmentary system to further prevent solar damage

stimulates fibroblasts and endoteliocytes to maintain a functional dermis

structure

enhances immune system response against pathogens.

Fischer TW et al. Melatonin as a major skin protectant: from free radical scavenging to DNA damage repair. Exp Dermatol 2008;17:713-30.

Bonnefont-Rousselot D et al. Melatonin: action as antioxidant and potential applications in human disease and aging. Toxicology 2010; 278:55-67.

Dreher F et al. Topical melatonin in combination with vitamins E and C protects skin from ultraviolet-induced erythema: a human study in vivo. Br J Dermatol 1998;139:332-9.

In the past, overactive melatonin receptor was thought to have a key role in vitiligo

pathogenesis.

Recent evidences on the prominent antioxidative actions of MN have then

suggested a

revision of that hypothesis.

According to these evidences, an insufficient intracutaneous synthesis and buffering

of MN

would lead to development of vitiligo when oxidative stress, cellular ⁄ subcellular or

DNA

damages occur because of insufficient scavenging and ⁄ or buffering activity.

In the skin, MN controls the dispersion and aggregation of melanin

throughout melanocytes, causing the skin to change color

(these variations follow MN circadian secretion cycle).

Fischer T et al. Melatonin in dermatology. Experimental and clinical aspects. Hautarzt 1999;50:5-11.

Slominski A et al. View point 4: melatonin hypothesis on the vitiligo pathogenesis. Exp Dermatol 2008; 17: 149-52

• Melanoma/carcinoma

• Psoriasis vulgaris

• Radioprotection

• Sarcoidosis

• Solar erythema

• Vitiligo

• Wound healing

MELATONIN

Slominski A et al. Hypothesis: possible role for the melaton'in- receptor in vitiligo: discussion paper. J Royal Soc Med 1989: 82: 539–541.

Skin disorders which could benefit from melatonin administration

• Aging

• Alopecia

• Atopic eczema

• Diabetic foot syndrome

• Hair greying

• Itching

Benefical effects of AOs molecules have been

investigated during last two decades.

Large part of these studies have used in

vitro models or animal models (mouse setting).

Few studies have been performed

on human beings, almost all based on limited

study group and without adequate controls.

Further investigations on human model, including randomized double-blind

trials

on large population groups, are necessary :

> to obtain statistically significant data

> to test different treatment modalities (oral vs topical,

alone vs combined) of the various AOs molecules.

AOs represents a natural tool for contrasting photo-damage

(photo-aging and photo-carcinogenesis) and vitiligo patogenesis.

Take home message

Thank you for the attention.