Stratum corneum fatty acids: their critical role in preserving barrier integrity during cleansing

Abstract

SynopsisStratum corneum (SC) bilayer lipids, specifically fatty acids, ceramides and cholesterol, contribute to the permeability barrier function of the skin. Normal skin cleansing is associated with damage to the SC lipids because cleanser surfactants, in addition to providing the desired effect of solubilizing and facilitating the removal of sebum and skin soils, have a propensity to disrupt bilayer lipids by extracting endogenous skin lipids or intercalating into the bilayer. Disrupted SC lipids are associated with a variety of pathological skin conditions, as well as with dry skin induced by harsh cleansing. In an attempt to preserve the barrier and mitigate the damage caused by frequent normal cleansing, the incorporation of physiologically relevant lipids into skin cleansers has become common in leading cleansing products. It has been noted that fatty acids are more susceptible to surfactant-induced removal than other lipids (eg, ceramides), an observation that may form the basis for a critically important strategy for replenishing SC lipids. This review will focus on the role of fatty acids in the structure and function of the SC, and the rationale for incorporation of stearic acid into moisturizing body cleansers to minimize their extraction by surfactants and replenish lost fatty acids to promote skin barrier preservation. R esum eLes lipides des bicouchesdu stratum corneum (SC), les acides gras en particulier, les c eramides, le cholest erol contribuent a la fonction de barri ere de perm eabilit e de la peau. Le nettoyage normal de la peau est associ e a des dommages aux lipides du SC parce que les tensioactifs nettoyants, en plus de fournir l'effet d esir e de solubilisation et d' elimination du s ebum et des souillures de la peau, ont une propension a perturber les lipides des bicouches par l'extraction de lipides endog enesde la peau ou ceux intercal es dans les bicouches. La perturbation des lipides du SC est associ ee a une vari et e d'affections cutan ees pathologiques, ainsi qu'avec la peau s eche induite par le nettoyage agressif. Dans une tentative pour pr eserver la barri ere et att enuer les d egâts caus es par le nettoyage fr equent normal, l'incorporation de lipides physiologiquement pertinents dans les nettoyants pour la peau est devenu habituel pour les produits de nettoyage de de qualit e. Il a et e not e que les acides gras sont plus sensibles a l' elimination induite par les tensio-actifs que d'autres lipides (par exemple, les c eramides), une observation qui pourrait constituer la base d'une strat egie cruciale pour la reconstitution des lipides du SC. Cet examen portera sur le rôle des acides gras dans la structure et la fonction du SC, et la justification de l'incorporation de l'acide st earique dans les nettoyants hydratants pour le corps afin de minimiser leur extraction par des agents tensioactifs et de reconstituer les acides gras perdus pour promouvoir la pr eservation de la barri ere cutan ee.

Cannabidiol exerts sebostatic and antiinflammatory effects on human sebocytes

“…Therefore, the novel and significant antiproliferative activity of CBD on human sebocytes in vitro and ex vivo documented here (Figure 2, A and I) is expected to greatly reduce sebum production in vivo. Moreover, it is also important to emphasize that, clinically, it is highly desirable that basal sebogenesis and viability of sebocytes are unaffected (Figure 1, A-C, and Figure 2, A-C) by CBD (at least in the noncytotoxic concentrations and after short-term treatments; Supplemental Figure 2, A-E), since a sufficient level of sebum production is a critical factor for maintaining proper function of the epidermal barrier, one of the central components of skin homeostasis (56).…”

Age- and Diabetes-Related Changes in the Free Fatty Acid Composition of the Human Stratum Corneum

“…Insights into pathogenetic relationships are important for performing a targeted substitution of the epidermal barrier function. For skin lipids, the problem in this case is that qualitative changes, in addition to quantitative changes, could be crucial, in particular for FFAs [28]. It should be mentioned that, aside from the SC, the epidermis is particularly good at synthesising large quantities of both even-and odd-numbered FFAs [29].…”

Synthetic ultra-long chain fatty acyl based amphiphilic lipids as a dual function excipient for the production of surfactant-free solid lipid nanoparticles (SF-SLNs): a physico-chemical study

“…Behenic acid has a melting point ~80 °C 23 , and is poorly absorbed by human body (absorption rate is ~30% compared with 95-98% of palmitic acid) 24,25 . It is also known as a dominant ultra-long fatty acyl in stratum corneum lipids 26,27 . Behenic acid is studied as a hydrophobic building block which provides high melting behavior and very tight molecular packing through strong acyl-acyl interactions 28 .…”