Understanding Solar Skin Elastosis-Cause and Treatment.

Photoageing, also called actinic ageing, is the main cause of prematurely aged skin. Our expertise in elastic fibers has led us to discover a process triggered in response to ultraviolet (UV) light and which upsets the balance of elastin fibers: there is too much elastin and insufficient lysyl oxidase (LOXL1) enzyme to form functional elastic fibers. This imbalance then leads to an accumulation of nonfunctional elastin, which forms aggregates. In addition to this imbalance, UV rays also induce elafin synthesis by fibroblasts. Known to be a marker of elastotic aggregates, elafin crystallizes the elastin fibers and stimulates the formation of aggregates that cannot be naturally eliminated by the skin. We developed a Hamamelis virginiana leaf extract that was able to restore both the balance between elastin and LOXL1 and to decrease the elafin synthesis to fight and correct the damage. This specific Hamamelis virginiana extract increased LOXL1 expression by twofold and decreased elafin synthesis. As a consequence, elastic fibers became functional and aggregates of unfunctional fibers decreased. The specific Hamamelis extract activity was confirmed in vivo with decreasing wrinkles and improving skin firmness.

How to help the skin cope with glycoxidation.

BACKGROUND: Protein glycation refers to the spontaneous reaction of reducing sugars with proteins and the subsequent formation of stable advanced glycation end products (AGEs). Glycation is linked with oxidative stress, and this association is called "glycoxidation". Glycoxidation alters the protein structure and function and causes tissue aging, as seen in human skin. Therefore, research on substances inhibiting glycoxidation appears to be crucial in the prevention of skin aging. With this aim, several plant extracts have been screened for antiglycation activity, and the results of the best candidates are presented in this article. METHODS: Glycation was studied on human skin proteins (collagen, elastin, and albumin) and on a model of reconstructed skin. Oxidative stress has been addressed by testing the copper-induced low-density lipoprotein oxidation, ultraviolet irradiation of glycated dermis, and carbonyl activation of human dermal fibroblasts. A clinical test evaluated the extent of oxidative stress induced by ultraviolet A irradiation. RESULTS: Among the tested products, several plant extracts have decreased the glycation effects on skin proteins collagen, elastin, and albumin. In addition, a plant extract has significantly inhibited the different forms of oxidative stress associated with protein glycation. CONCLUSIONS: We have demonstrated that plant extracts can relieve the deleterious effects of glycation on human skin. Moreover, a plant extract rich in antioxidant molecules has also significantly preserved the human skin from glycoxidation attacks.

Modulation of CD86 expression in skin dendritic cells does not always correlate with changes in DC motility, migration and allostimulatory functions.

CD86 expression is a well-known activation marker of dendritic cells (DC). In this study, we compared the level of CD86 expression in monocyte-derived skin DC with their motility, migratory abilities and allostimulatory capabilities. We show that motility and migration could be uncoupled from activation and that the immune response-modulating effects of certain compounds may correlate with down-regulation of CD86 expression rather than with effects on motility and migration.