Skin researchers analyzed the differences in the gene regulation of young and old skin. Through molecular comparisons of skin cells they found over 20,000 different genes. Of these, several hundred exhibited age-specific reactions to external influences. The researchers selected the most important of these genes to serve as markers of skin aging. By characterizing the markers for old and young skin, the researchers established the basis for a special DNA chip, on which the gene probes for skin aging are anchored.

This DNA chip is a valuable source of information for the researchers. For instance, they can now find out how substances such as botanical extracts influence the activity of genes in the skin cells. If genes that are typically found in young skin react to a substance, this is a strong indication that it may have the desired rejuvenating effect.

Botanical actives, genes and data analysis
In the search for new botanical active ingredients, the DNA chip has already been used to analyze the effects of numerous extracts. First of all, the scientists expose skin cells to the extracts in a test tube. To determine whether the cells react to the substances with increased or decreased gene activity, the researchers then extract the cell components and apply them to the DNA chip. They examine the treated chips and generate raw data. Analyzing the data acquired with the help of the DNA chip is the province of other specialists such as chemoinformaticians and bioinformaticians. With the help of special software, they are able to identify the big picture indicated by the data. And they can decide whether the relationships they recognize will be useful or not.

Combination of optimal ingredients
Skin aging is a very complex process, and the action mechanisms of optimal anti-aging cosmetics have to be just as intricate. With the help of DNA chip technology, the skin research team has already studied a large number of substances and has been able to separate the wheat from the chaff. Individual substances have been observed to improve cell communication, strengthen cellular connections, and increase the lipid or collagen content. However, only a suitable combination of active ingredients will be able to halt or slow down the complex interactions that take place at various levels in the skin aging process.

The trend: Personalized cosmetics
DNA chip technology promises to open up yet more doors to the future development of cosmetic products. Questions going far beyond skin aging can be addressed. How do certain skin types react to environmental stress? Why is one skin type more sensitive than another? What are the biological causes of dry skin? Henkel Research hopes to be able to answer these questions in the future. The DNA chip is a tool which makes it relatively easily to compare the effects of different substances on skin aging.