After more than ten years of effort, researchers have discovered a substance capable of penetrating the skin and making it brown without exposure to ultraviolet rays of the sun, thus avoiding the risk of developing cutaneous cancer.
Unlike traditional self-tanning creams, which only color the surface layer of the skin, this molecule acts by stimulating cells that produce pigments whose role is to absorb ultraviolet radiation, researchers say.
The study is published Tuesday in the American journal “Cell Reports”. The new molecule has yet to undergo more preclinical testing before determining its safety in humans.
This substance applied as a cream also makes it possible to brown the epidermis of red-haired mice, which like humans are more likely to develop skin cancer under the effect of ultraviolet radiation.
This work stems from a study published in 2006 in the British scientific journal “Nature” which showed that another substance, forskolin, produced by the plant known as the “coléus” of India, could induce browning of red-skinned mice Without exposure to ultraviolet radiation.
But scientists quickly discovered that this molecule could not penetrate human skin.
Not protected by a thick layer of hair, the human epidermis has evolved over time to develop protections against, among others, the cold, heat and ultraviolet rays of the sun.
“Human skin is a formidable barrier, difficult to penetrate,” says Dr. David Fisher, head of the Department of Dermatology at the American Hospital Massachusetts General and a professor at the Harvard Medical School, the main author of this discovery.
“Ten years later we found a solution with a different class of molecules … smaller and able to pass through the lipids to target another enzyme acting on the same genetic pigmentation mechanism of the skin,” says the researcher .
Scientists tested these molecules on samples of human skin in the laboratory and found that they browned more or less depending on the doses of this substance and the frequency of applications. This artificial tan lasted several days.
“The potential importance of this study will ultimately lie in a new skin protection and skin cancer prevention strategy,” Dr. Fisher said.
“The skin is the largest organ in our body that can be affected by cancer and the majority of cases are related to exposure to ultraviolet rays,” he said.