Molecular mechanisms of skin rejuvenation
Researchers from the University of California at Davis and the University of Beijing, led by Professor Xu Cao, have deciphered the mechanism of action of alpha-hydroxy acids, which are the active ingredient of cosmetic chemical peels and wrinkle-smoothing creams.
Alpha hydroxy acids, which belong to the group of weak acids and are usually isolated from natural sources such as sugar cane, sour milk, apples and citrus fruits, are well known in the cosmetology industry due to their ability to improve the appearance and condition of the skin. However, according to one of the leaders of the work, Professor Jie Zheng, despite many years of use in cosmetology, it was still practically unknown how these compounds peel off the surface layers of the skin, exposing a fresh smooth surface.
As it turned out, this mechanism is based on the activation of an ion channel known as transient receptor potential vanilloid 3 (TRPV3), localized in the membrane of keratinocytes – the most numerous skin cells. Earlier studies have demonstrated the important role of this receptor in the physiological functions of the skin and its sensitivity to temperature.
As a result of a series of experiments in which researchers recorded the strength of electric charges passing through cell cultures treated with alpha-hydroxy acids, a model was developed describing the process of penetration of the smallest and most accessible of alpha-hydroxy acids – glycolic (its structural formula and molecule model are shown in the figure) into keratinocytes and the formation of acidic free protons.
A high level of acidity causes a strong activation of the TRPV3 ion channel, which opens and allows the flow of calcium ions into the cells. Since new protons also enter the cell through an open channel, this process is self-sustaining. The resulting overload of the cell with calcium ions leads to its death and skin detachment.
In addition to keratinocytes, sensitive not only to acidity, but also to temperature, TRPV3 are found in the cell membranes of many parts of the nervous system. The researchers suggest that these ion channels can perform many important physiological functions, including pain control. They believe that over time, TRPV3 may become an important target not only for cosmetic products, but also for painkillers and drugs for the treatment of skin diseases.
Article X. Cao et al. Intracellular Proton-mediated Activation of TRPV3 Channels Accounts for the Exfoliation Effect of b-Hydroxyl Acids on Keratinocytes published in the Journal of Biological Chemistry.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the UC Davis Health System:
UC Davis researchers identify cellular basis for how anti-aging cosmetics work.
16.08.2012