These findings prompted scientists to wonder whether the higher skin-cancer incidence in light-skinned people is due either to their shortage of protective eumelanin
or an abundance of oxidizing pheomelanin.
High plasma levels of a eumelanin
precursor, 6-hydroxy-5-methoxyindole-2-carboxylic acid as a prognostic marker for malignant melanoma.
Therefore, the mutations in this gene can affect eumelanin
deposition, which gives the darker pigmentation.
This bird also had mainly black plumage, but with scattered white feathers on the head and surrounding the beak and eyes (indicating a reduction in eumelanin
concentration; van Grouw 2006).
Darker skin does offer some increased protection against ultraviolet radiation, as people with dark skin have a higher melanin and eumelanin
(brown-black pigment) content, which in turn reduces the risk of skin cancer induced by ultraviolet radiation from sun exposure.
The images show that melanomas tend to have more eumelanin
, a kind of skin pigment, than healthy tissue.
is brownish-black, and phaeomelanin reddish-yellow.
and pheomelanin have the ability to generate active oxygen species, such as [O.
MELANOTAN(TM) is EpiTan's brand name for (Nle4,D-Phe7)-alpha-MSH, a synthetic analogue of the naturally occurring hormone alpha-MSH, which stimulates eumelanin
the production of the colour pigments eumelanin
(EM) and pheomelanin (PM) in melanocytes, or the lack of it, is the main material basis of the color patterns observed in mammals (StepHane et al.
It uses the power of the dark pigment eumelanin
, which protects skin cells.
pigments often signal competitive ability and social dominance (Senar 1999), and act as honest signals of male parental quality in a few species (Siefferman and Hill 2003).