News News

Increase of the benzothiazole moiety content of pheomelanin pigment after endogenous free radical inducement

Pheomelanin, the sulfurated form of melanin pigment, is known to produce reactive oxygen species (ROS) and oxidative stress-mediated cytotoxicity. Previous studies have shown a conversion of the benzothiazine moiety of pheomelanin to the benzothiazole moiety under heat or energetic radiation exposure, but it is unknown whether endogenous conditions can also produce this structural change. An endogenous free radical production was experimentally induced by exposing male zebra finches Taeniopygia guttata to diquat dibromide in drinking water during the development of pheomelanin-pigmented flank feathers. The benzothiazine-to-benzothiazole ratio of feather pheomelanin decreased more and was significantly lower in diquat-treated birds than in controls. Therefore, endogenous free radicals, and not only environmental radiation, can also promote structural changes in pheomelanin. While it was previously assumed that benzothiazine is responsible for the redox reaction of pheomelanin, recent findings suggest that benzothiazole has a greater ability to deplete antioxidants. Therefore, the possibility should be considered that the supplementation of antioxidants to limit the effects of endogenous free radicals can contribute to prevent melanoma, a disease that is favored by oxidative stress produced by pheomelanin. informacion[at]ebd.csic.es: Rodríguez-Martínez et al (2020) Increase of the benzothiazole moiety content of pheomelanin pigment after endogenous free radical inducement. Dyes and Pigments. DOI 10.1016/j.dyepig.2020.108516


https://www.sciencedirect.com/science/article/abs/pii/S0143720820308378
Average (0 Votes)

Latest News Latest News

Strategies shrubby junipers adopt to tolerate drought differ by site

Drought-induced dieback episodes are globally reported among forest ecosystems but they have been understudied in scrublands. Chronically-stressed individuals are supposed to be more vulnerable...

Second notice: Scientists warn of increasing threats posed by invasive alien species

Biological invasions are a global consequence of an increasingly connected world and the rise in human population size. The numbers of invasive alien species – the subset of alien species...

Carp eggs survive transport through avian intestine

Fish have somehow colonized isolated water bodies all over the world without human assistance. It has long been speculated that these colonization events are assisted by waterbirds, transporting...

Dwarfism in continental populations of natterjack toads in the absence of genetic isolation

Ample variation in body size is common in vertebrates over extensive geographical distances, or in isolated populations, where effective geographical barriers may cause dwarfism or gigantism. The...

Generalized hybridization between commercial and native individuals of bumble bees

Every year more than 1 million commercial bumblebee colonies are deployed in greenhouses worldwide for their pollination services. While commercial pollinators have been an enormous benefit for...