Roles of reactive oxygen species in UVA-induced oxidation of 5,6-dihydroxyindole-2-carboxylic acid-melanin as studied by differential spectrophotometric method

被引：41

作者：

Ito, Shosuke ^{[1
]}

Kikuta, Marina ^{[1
]}

Koike, Shota ^{[1
]}

Szewczyk, Grzegorz ^{[2
]}

Sarna, Michal ^{[2
]}

Zadlo, Andrzej ^{[2
]}

Sarna, Tadeusz ^{[2
]}

Wakamatsu, Kazumasa ^{[1
]}

机构：

[1] Fujita Hlth Univ, Dept Chem, Sch Hlth Sci, Toyoake, Aichi, Japan

[2] Jagiellonian Univ, Dept Biophys, Fac Biochem Biophys & Biotechnol, Krakow, Poland

来源：

PIGMENT CELL & MELANOMA RESEARCH | 2016年 / 29卷 / 03期

基金：

日本学术振兴会;

关键词：

eumelanin; 5; 6-dihydroxyindole-2-carboxylic acid; UVA; reactive oxygen species; singlet oxygen; ELECTRON-SPIN-RESONANCE; HUMAN SKIN PIGMENTATION; SINGLET OXYGEN; HYDROGEN-PEROXIDE; SOLUBLE EUMELANIN; PORCINE EUMELANIN; MOLECULAR-OXYGEN; ULTRAVIOLET-A; DNA-DAMAGE; RADIATION;

D O I：

10.1111/pcmr.12469

中图分类号：

R73 [肿瘤学];

学科分类号：

100214 ;

摘要：

Eumelanin photoprotects pigmented tissues from ultraviolet (UV) damage. However, UVA-induced tanning seems to result from the photooxidation of preexisting melanin and does not contribute to photoprotection. We investigated the mechanism of UVA-induced degradation of 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-melanin taking advantage of its solubility in a neutral buffer and using a differential spectrophotometric method to detect subtle changes in its structure. Our methodology is suitable for examining the effects of various agents that interact with reactive oxygen species (ROS) to determine how ROS is involved in the UVA-induced oxidative modifications. The results show that UVA radiation induces the oxidation of DHICA to indole-5,6-quinone-2-carboxylic acid in eumelanin, which is then cleaved to form a photodegraded, pyrrolic moiety and finally to form free pyrrole-2,3,5-tricarboxylic acid. The possible involvement of superoxide radical and singlet oxygen in the oxidation was suggested. The generation and quenching of singlet oxygen by DHICA-melanin was confirmed by direct measurements of singlet oxygen phosphorescence.

引用

页码：340 / 351

页数：12

共 69 条

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