Researchers at Massachusetts General Hospital (MGH) and the Cancer Institute Dana-Farber (DFCI) in the United States, have developed a way to increase pigmentation in human skin without the damaging effects of ultraviolet radiation . A study in Cell Reports followed a 2006 project published in Nature that identified the underlying molecular pathways to the tanning response and induction of tanning in a mouse strain that normally does not produce melanin.
Director David E. Fisher both studies, head of the Department of Dermatology at MGH, says that “activation of the pigmentation by this new class of small molecules is physiologically identical to UV – induced pigmentation without the harmful effects of radiation DNA “. He adds that ” we need to carry out safety studies , which are always essential compounds with potential new treatment and better understand the actions of these agents.”
Nature study in 2006 Fisher’s team used a topical compound called forskolin to induce tanning in a strain of mice red hair, in which a genetic variant interrupts the path of melanin pigment production. Forskolin activated protein pathway in pigmentation , preventing interruption and inducing the production of protective dark pigment called eumelanin.
Tests on human skin with forskolin and a compound related to similar action were unsuccessful , probably because human skin is about five times thicker than that of mice. The researchers then looked for a different approach. Enzymes called kinases inducible salt (SIK) regulate the transcription of a protein that works in the way of pigmentation. A group of experts in Japan has shown that the inhibition of expression of SIK also active pigmentation in mice.
Initial experiments with an inhibitor of SIK produced a tanning marked in the same strain of mice red hair used in the study of Nature. The darkening increased with daily treatment and gradually decreased when the application is stopped, such as a normal tanning . When this compound was shown to have limited activity in human skin samples , Fisher’s team went to the laboratory in DFCI Natahanael Gray, co – author of the current study.
New class of inhibitors
They found that a new class of inhibitors SIK small molecules was able to better penetrate human skin samples grown and also induce significant darkening after eight days of daily administration. The examination of skin samples confirmed that the pigment eumelanin produced and deposited near the surface of the skin typical of what is observed with tans induced patterns UVA , suggesting the activation thereof via pigmentation.