A new chemical that mimics sunlight to produce skin tan may potentially prevent skin cancer by producing pigment that blocks harmful UV radiation.
Researchers also hope that the substance, which has only been tested on mice and skin samples in lab petri dishes, can slow the appearance of aging by producing the dark melanin tone that serves as the natural sunblock of the body sans the damage caused by UV radiation.
Skin Tone And Melanoma
People who have dark skin tone and those whose skin tan easily tend to have lower risk of melanoma, the deadliest form of skin cancer. Melanoma is the sixth most common cancer in the United States with more than 76,000 cases in 2016 alone.
The dark pigment, melanin, offers protection against the disease as it dissipates over 99.9 percent of absorbed UV rays limiting the damage caused by radiation to the cells, which contributes to the development of cancer.
Protection Against Sunburn And Cancer
A variant of a gene called MC1R dictates whether a person burns or tans in the sun. In individuals who tan, the gene triggers a series of reaction during sun exposure that causes the skin cells to produce melanin. Redheads can theoretically produce the pigment in the cells but the chain reaction is not set in motion.
For the new study published in the journal Cell, David Fisher, from the Massachusetts General Hospital, and colleagues, found that the small molecule — dubbed SIK inhibitor — can be used to artificially turn on the process of melanin production up to the point where the MC1R gene causes blockage.
When the researchers applied the chemical to a skin sample in a petri dish, they found that the latter darkened and the tan lasted days after the initial application. When they tried this on mice, the animals turned almost jet black as early as within a day and were found to have strong protection against sunburn and cancer.
After more than a week or so, as the skin cells sloughed off the surface, the color faded just like normal tans do but the mice did not seem to suffer from other obvious side effects.
Sunscreen And Darkening Tanning Products
Fisher said that combining sunscreen and darkening tanning products could be a new way to fight skin cancer.
"We see pretty potent efficacy in human skin cells," Fisher said. "What I view as a big opportunity here is something that might be able to enhance the protection provided by sunscreens currently."
While currently available sunscreens provide protection against UV rays, their blocking effects also mean that the skin does not raise its natural tanning defense against the sun with melanin, potentially leaving the skin more vulnerable to the damages of the sunlight if sunscreen is not properly and often used.
Fisher said that a tanning agent may address this problem by improving the sunscreen's protective effect.
"Sunscreen is extremely important; there definitely is protection, but [its] efficacy in melanoma and basal cell carcinoma is surprisingly and frustratingly incomplete," Fisher said.