Skin Changes During Ageing.

The skin provides the primary protection for the body against external injuries and is essential in the maintenance of general homeostasis. During ageing, resident cells become senescent and the extracellular matrix, mainly in the dermis, is progressively damaged affecting the normal organization of the skin and its capacity for repair. In parallel, extrinsic factors such as ultraviolet irradiation, pollution, and intrinsic factors such as diabetes or vascular disease can further accelerate this phenomenon. Indeed, numerous mechanisms are involved in age-induced degradation of the skin and these also relate to non-healing or chronic wounds in the elderly. In particular, the generation of reactive oxygen species seems to play a major role in age-related skin modifications. Certainly, targeting both the hormonal status of the skin or its surface nutrition can slow down age-induced degradation of the skin and improve healing of skin damage in the elderly. Skin care regimens that prevent radiation and pollution damage, and reinforce the skin surface and its microbiota are among the different approaches able to minimize the effects of ageing on the skin.

Development of a LC-MS/MS method to monitor palmitoyl peptides content in anti-wrinkle cosmetics.

Palmitoyl peptides are anti-aging agents widely used in cosmetics. This article describes the development of a LC-MS/MS analytical procedure that allows, after a liquid-liquid extraction procedure, their unambiguous detection in cosmetic formulation. MS/MS detection is shown to be specific regarding placebo formulations. Limits of quantification, linearity, accuracy and precision of the method were estimated. The results presented show that palmitoyl peptides can be thus reliably assayed. The palmitoylated pentapeptide palmitoyl-lysyl-threonyl-threonyl-lysyl-serine (pal-KTTKS) was assayed in anti-wrinkle creams using palmitoyl-glycyl-histidyl-lysine (pal-GHK) as internal standard. From the results obtained, the influence of the formulation on pal-KTTKS availability is evidenced.