A new study has discovered a group of compounds that could give you that suntan glow without having to go out in the sun. If proven safe in clinical trials, you could sport your suntan all year round, and what’s more, they could cut your risk for melanoma, that is helpful in skin cancer prevention.
Exposure to harmful UV rays from being out in the sun or using tanning beds is associated with an increased risk of skin cancer. Similarly, and although conclusive evidence is lacking at the moment, the use of tanning products containing the synthetic hormone melanotan has also been linked with an increased risk of skin cancer.1 However, for those looking to sport a healthy tan through those long winter months, a safer alternative could be in the works.
A paper published in Cell Reports in June 2017 reports the discovery of a new set of compounds that when applied on human skin results in the production of the pigment melanin, which imparts color to skin.2 When the skin is exposed to UV rays, the melanocyte-stimulating hormone activates the melanocortin-receptor-1 (MC1R), a protein located on the melanocyte cell surface. This, in turn, triggers downstream cellular signalling events leading to the production of melanin. Individuals with red hair and light skin tones carry variants of the MC1R gene that fails to get activated upon exposure to UV light, and therefore, these individuals tend to burn and not tan when exposed to UV light.
Previous studies in a red-haired strain of mice, which carry an inactive variant of the Mc1rgene, show that topically applying a chemical that triggered signalling events downstream of the MC1R switch could induce melanin synthesis and protect against UV damage. Taking their cue from this and other work, researchers targeted a protein called salt-inducible kinase (SIK), which blocks microphthalmia-associated transcription factor, a key protein involved in melanin expression downstream of MC1R. They purchased the chemical compound HG 9-91-01, which is known to inhibit SIK activity, and applied it to the shaved skin of the red-haired mice daily for 7 days. The skin of these mice turned very dark after 7 days of application.
However, HG 9-91-01 cannot penetrate human skin; therefore, the researchers created slightly different versions of this compound that could penetrate the human skin more effectively. When these new variants of HG 9-91-01 were applied daily for 8 days to fragments of human skin saved from surgeries, the skins turned significantly dark.
To summarize, the researchers were able to induce melanin production in mouse and human skin by taking a UV-independent approach. The compounds they identified need to be tested in clinical trials for safety, efficacy, and optimum usage before they are approved for use. For people who use tanning beds, these compounds could be safer alternatives for getting a suntan, as they may assist in skin cancer prevention.The researchers hope that the compounds will be used to supplement existing sunscreens, and while being useful for all, will be particularly helpful for light-skinned individuals who are at greatest risk for skin cancer.
Written by Usha B. Nair, Ph.D.
- Habbema L, Halk AB, Neumann M, Bergman W. Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review. Int J Dermatol. 2017Mar 7. doi: 10.1111/ijd.13585. [Epub ahead of print] Review. PubMed PMID:28266027.
- Mujahid N, Liang Y, Murakami R, Choi HG, Dobry AS, Wang J, Suita Y, WengQY, Allouche J, Kemeny LV, Hermann AL, Roider EM, Gray NS, Fisher DE. AUV- Independent Topical Small-Molecule Approach for Melanin Production in Human Skin. Cell Rep. 2017 Jun 13;19(11):2177-2184. doi: 10.1016/j.celrep.2017.05.042. PubMed PMID: 28614705.