Nature for skin barrier August 04, 2015 15:25
Meet filaggrin: a protein that moisturises your skin. It lives in your epidermis. Have you ever seen the abbreviation ‘NMF’ among the ingredients of moisturising creams? It is the natural moisturising factor, a product of filaggrin. We start to worry about wrinkles already around the age of thirty. Lines and wrinkles appear when, among other things, we start losing filaggrin and our epidermis becomes thinner and thinner. Natural cosmetics can help with this: essential oil of damask rose increases the amount of filaggrin (Kim et al., 2010). It also helps in the maturation of keratinocytes – the skin cells that produce filaggrin. As a result the skin can regenerate and renew its barrier. Better skin barrier means less water loss and that means – more moisture.
But what is ‘skin barrier’? The epidermis resembles a house: on the outside, where the keratinocytes completed their journey from deeper in the skin and died, there is a layer of ‘cement’ and ‘bricks’. These are fatty acids, cholesterol, ceramides and water. Detergents, alcohol, hot water, UV radiation and grazes damage this cement. Water escapes from it and the skin wrinkles and flakes. Eczema, dermatitis, excessive dryness of the skin all result from such leaky cement and abnormalities in the maturation of keratinocytes.
Osawa et al., 2011: Comparison of skin with healthy barrier with skin where filaggrin is malfunctioning.
Argan oil also strengthens the skin barrier (Boucetta et al., 2013). As shown in a study on thirty postmenopausal women, after two months of rubbing 10 drops of this oil into a forearm the level of water in the skin increases, while less water leaks out. This effect could be thanks to the presence of linoleic acid (31-35%), which is one of the ingredients of ceramides, or the ‘bricks’ in the dead layer of the epidermis. Another natural substance that moisturises the skin is aloe vera (Aloe barbadensis). Scientists discovered it when studying the effects of different concentrations of aloe vera extract (0.10%, 0.25% and 0.50%) on women (Dal'Belo et al., 2006). They measured water content and the transepidermal water loss (TEWL) after single application and after one and two weeks. After single application only the two stronger concentrations increased the amount of moisture in the skin, but after 2 weeks all three worked well. There were no changes, however, in the water loss. It seems, therefore, that aloe vera has a different mechanism of action than the rose damask oil: it increases the levels of moisture in the epidermis even if water is still leaking out.
So keratinocytes form the structure of the skin and their dead remains protect it with ‘cement’. And what makes the skin elastic and firm? This we will learn in the next part!
Jadwiga Nazimek ©
Boucetta, K. Q., Z. Charrouf, H. Aguenaou, A. Derouiche, and Y. Bensouda, 2013, Does Argan oil have a moisturizing effect on the skin of postmenopausal women?: Skin Res Technol, v. 19, p. 356-7.
Dal'Belo, S. E., L. R. Gaspar, and P. M. Maia Campos, 2006, Moisturizing effect of cosmetic formulations containing Aloe vera extract in different concentrations assessed by skin bioengineering techniques: Skin Res Technol, v. 12, p. 241-6.
Kim, J. H., D. K. Choi, S. S. Lee, S. J. Choi, C. D. Kim, T. J. Yoon, and J. H. Lee, 2010, Enhancement of keratinocyte differentiation by rose absolute oil: Ann Dermatol, v. 22, p. 255-61.
Osawa, R., M. Akiyama, and H. Shimizu, 2011, Filaggrin gene defects and the risk of developing allergic disorders: Allergol Int, v. 60, p. 1-9.