Our skin has a built-in hydration system known as "natural moisturizing factors," or NMF for short, that help keep it smooth, hydrated, and healthy-looking. In a balanced state, the skin does its job well, but if you feel superficial dryness and tightening and you notice the formation of shallow lines - your skin craves hydration. The key to the problem lies precisely in the reduced level of NMF. By recognizing the importance of NMF for skin health, you will be able to use the power of your own body's natural processes, as well as the topical application of NMF, so that your skin takes on a renewed and healthier appearance.
What are NMF and what makes them excellent allies in maintaining adequate skin hydration?
Maintaining the water balance in the stratum corneum is regulated by intercellular lipids that create an obstacle to water transport and a complex mixture of low molecular weight water-soluble compounds such as free amino acids, pyrrolidone-carboxylic and trans-urocanic acids, but also inorganic salts, sugars and urea, the common the name NMF, i.e. natural wetting factors. It is a cocktail of ingredients that our skin produces independently , and whose role is to bind water inside corneocytes , aggregated keratin filaments, thus keeping the skin adequately hydrated . Adequate hydration of the stratum corneum has three main functions: it maintains the elasticity of the skin by protecting it from damage, enables the activity of hydrolytic enzymes in the desquamation process, and contributes to the optimal barrier function of the stratum corneum . In healthy skin, the tissue contains more than 10% water.
The importance of NMF lies in the fact that these highly hygroscopic substances are excellent humectants that like magnets attract and bind water from the atmosphere , drawing it into the corneocytes and acting as very effective moisturizers. Essentially, the amount of NMF in the stratum corneum determines how much water it can hold at a given humidity. These observations make it clear that NMFs are crucial for maintaining the physical properties of the stratum corneum.
NMF ingredients create interactions with keratin fibers, reducing intermolecular forces between fibers and increasing skin elasticity . Elasticity is important to keep the skin looking healthy and supple and to prevent cracking or peeling due to mechanical stress. Also, the stratum corneum is a dynamic structure that requires adequate hydration for the functioning of specific enzymes that are essential, not only for desquamation, but also for the creation of NMF itself. Another important property of NMF is its participation in the creation and maintenance of the acidic pH of the skin surface , the so-called "acid mantle", to protect the skin from the colonization of pathogenic bacteria.
What is the mechanism of formation of NMF?
Research has shown that filaggrin , the main structural protein in the stratum corneum , is the dominant source of free amino acids and their derivatives, which together make up more than 50% of the total content of NMF , and are formed after the breakdown of the epidermal protein filaggrin during the keratinization process. Profilagrin, a phosphorylated precursor of filaggrin with a large molecular weight located in the keratohyaline granules of the granular layer, which represents an osmotically inactive repository of NMF, releases functionally active monomers of filaggrin with a smaller molecular weight through a complex cascade of dephosphorylation and proteolytic processing, which, apart from participating in the aggregation of keratin filaments, are inside the stratum corneum are further cleaved into short polypeptides, and ultimately they are completely broken down, resulting in the corresponding amino acids and their derivatives that are part of NMF - osmotically active compounds that regulate skin hydration.
It is interesting to note that NMF undergo seasonal changes: filaggrin degradation and NMF production increase at low humidity and decrease at high humidity . In addition, filaggrin hydrolysis is not conditioned by the age of an individual corneocyte, but begins when the cell reaches a critical point during its journey through the stratum corneum to the skin surface, and further research has proven that the signal that triggers filaggrin degradation is actually the gradient of water activity in the stratum corneum.
How to prevent skin dehydration with topical application of NMF?
Dehydrated skin is a universal problem of all skin types experienced by the vast majority of people during their lifetime , and dehydration occurs as a result of disruption of the skin's hydrolipidic barrier, as a result of transepidermal water loss (TEWL). Although any skin type can experience dehydration, it often occurs precisely in oily and combination skin using inadequate products . Too frequent exfoliation, improper cleansing of the skin or the use of products with drying ingredients lead to evaporation of moisture from the deeper layers of the skin, which ultimately manifests as dehydrated skin that lacks NMF. Such skin can be recognized by surface tightening, flaking and the appearance of shallow lines.
About a third of the water contained in the stratum corneum is bound, while the rest is free water. Increasing the level of free water has no effect on the elasticity of the stratum corneum . Therefore, supplementing the supply of NMF by external application is a successful approach to the modification of skin that craves hydration . This is where the topical application of NMF comes into play, which restores lost moisture to the skin and supports the maintenance of optimal skin moisture.
Skintegra products containing NMF
If your skin craves hydration, after gentle and non-drying skin cleansing, we recommend balancing the skin with Nectar - a pH-optimized juicy essence in a spray enriched with a bunch of NMFs that refresh and awaken the skin and restore lost moisture. Nectar serves as an excellent base for your favorite serum and/or cream, which is important to apply immediately after applying Nectar to lock in moisture and prevent it from evaporating from the skin. As an added plus, you can use Nectar for refreshment at any time of the day!
As a treatment product for repairing or preventing dehydration in all types, Hyperdew - a mask whose formula contains NMF in a concentration of up to 30%, is an excellent choice. Hyperdew is used a couple of times a week in the evening routine, and it provides superior hydration compared to classic face masks, strengthens the skin's resistance and restores its freshness and radiance.
Both products can easily fit into any routine: Nectar for frequent use, and Hyperdew as an occasional treatment and relaxing ritual that raises the level of hydration to a new level overnight.
Literature:
- Harding, CR & Rawlings, AV. (2006). Effects of natural moisturizing factor and lactic acid isomers on skin function. Dry Skin and Moisturizers: Chemistry and Function. 187-209.
- Fowler, J. (2012). Understanding the role of natural moisturizing factors in skin hydration. Practical Dermatology. 36-40.
- Cepelak, Ivanai & Dodig, Slavica & Filipovic-Grcic, Jelena. (2016). Fillagrin - Multifunctional Protein. Acta medica Croatica: journal of the Croatian Academy of Medical Sciences. 70. 125-130.
- Baumann, Leslie. (2014). Cosmeceuticals and Cosmetic Ingredients. 91