The Pro-Oxidant Activity of Pheomelanin is Significantly Enhanced by UVA Irradiation: Benzothiazole Moieties Are More Reactive than Benzothiazine Moieties.

ABSTRACT: It is generally considered that eumelanin (EM) is photoprotective while pheomelanin (PM) is phototoxic. A recent study using a mouse model demonstrated that PM produces reactive oxygen species (ROS) that cause DNA damage and eventually lead to melanomagenesis. A biochemical study showed that PM possesses a pro-oxidant activity. PM consists of benzothiazine (BT) and benzothiazole (BZ) moieties, BT moieties being transformed to BZ moieties by heat or light. In this study, we compared the effects of ultraviolet A (UVA) irradiation using synthetic PMs with different BT to BZ ratios and using various coat color mouse hairs. We found that UVA irradiation of BZ-PM increased glutathione (GSH) depletion and generated more H₂O₂ than UVA irradiation of BT-PM. Non-irradiated controls did not exhibit s

SUBMITTER: Tanaka H 

PROVIDER: S-EPMC6213070 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature