Inhibition of UVA-mediated melanogenesis by ascorbic acid through modulation of antioxidant defense and nitric oxide system.
Arch Pharm Res
; 34(5): 811-20, 2011 May.
Article
em En
| MEDLINE
| ID: mdl-21656367
ABSTRACT
Ascorbic acid (AA) has been well known as a skin whitening agent, although attempts have been made to evaluate its protective role against ultraviolet (UV)-induced skin hyperpigmentation or increased melanin production. While melanogenesis is a defense mechanism of the skin against UV irradiation, melanin overproduction may also contribute to melanoma initiation. UVA might play a role in melanogenesis through promoting oxidative stress, which occurs as the result of increased formation of oxidants and/or reactive nitrogen species (RNS) including nitric oxide (NO). Therefore, we investigated the antimelanogenic effect of AA (7.5-120 µM) in association with its inhibitory effect on UVA-induced oxidant formation, NO production through endothelial and inducible NO synthases (eNOS and iNOS) activation and impairment of antioxidant defense using G361 human melanoma cells. Our study demonstrated a comparable ability of AA with that of kojic acid, a well-known tyrosinase inhibitor in inhibiting mushroom tyrosinase. Melanin content was reduced by AA, but neither tyrosinase activity nor mRNA levels were reduced by AA at non-cytotoxic concentrations in UVA-irradiated G361 cells. AA was shown to inhibit UVA-mediated catalase (CAT) inactivation, glutathione (GSH) depletion, oxidant formation and NO production through suppression of eNOS and iNOS mRNA. We report herein that AA can protect against UVA-dependent melanogenesis possibly through the improvement of antioxidant defense capacity and inhibition of NO production through down-regulation of eNOS and iNOS mRNA.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
/
Prevencao_e_fatores_de_risco
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Radiacao_solar
Base de dados:
MEDLINE
Assunto principal:
Ácido Ascórbico
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Raios Ultravioleta
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Estresse Oxidativo
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Melaninas
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Melanócitos
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Óxido Nítrico
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Antioxidantes
Limite:
Humans
Idioma:
En
Revista:
Arch Pharm Res
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Tailândia