A particular coloring agent found in auburn hair might possess an unexpected capability: transforming a harmful substance into a vibrant hue.
Researchers investigating the reddish-orange melanin present in avian plumage have uncovered evidence that its formation process can contribute to the prevention of cellular deterioration.
This pigment is identified as pheomelanin, and its creation necessitates an amino acid known as cysteine. An excessive buildup of cysteine within cells can precipitate oxidative harm.
According to investigators from Spain’s National Museum of Natural Sciences, individuals with genetic predispositions for red hair may possess specialized cellular mechanisms capable of converting surplus cysteine, whether from nutritional intake or environmental exposure, into pigment.
Utilizing zebra finches as a biological model, the research collective demonstrated that pheomelanin can fulfill a protective function in maintaining cellular integrity.
In experimental conditions, male finches unable to synthesize pheomelanin exhibited elevated markers of oxidative stress when subjected to a diet rich in cysteine for a month, in contrast to their counterparts that could produce the pigment.
Female zebra finches, which do not naturally produce pheomelanin, remained unaffected by a pharmacological agent designed to inhibit its synthesis. While they also displayed subtle indications of increased oxidative damage when supplemented with extra cysteine compared to a control group of females not receiving the supplement, this disparity was deemed not statistically significant.
These observations collectively imply that an overabundance of cysteine contributes to cellular damage and that the synthesis of pheomelanin offers a degree of protection against such detrimental effects.
Within the human body, pheomelanin production is primarily concentrated in areas such as the lips, nipples, and genitals, although individuals with red hair also feature it in their hair and skin.
“These findings constitute the inaugural experimental validation of a physiological role for pheomelanin, specifically its capacity to mitigate the toxicity associated with excess cysteine. This provides enhanced insight into melanoma susceptibility and the evolutionary processes shaping animal coloration,” state the study’s authors.
The research was disseminated in the journal PNAS Nexus.
