In vivo Human Skin Barrier Modulation by Topical Application of Fatty Acids

Abstract

The in vivo effects of fatty acids on skin barrier function were assessed by measuring: (i) transepidermal water loss (TEWL), (ii) diffusion lag times for hexyl nicotinate (HN), and (iii) irritant skin response using laser Doppler velocimetry (LDV) in combination with visual scoring. Two classes of fatty acids have been investigated: straight-chain saturated fatty acids (SFA), having 6–12 carbon atoms, and unsaturated fatty acids (UFA): oleic, linoleic, α-linolenic and arachidonic acids. It has been reported that these acids can enhance the permeation of various compounds across the skin. After topical and occlusive application as a solution in propylene glycol (PG) for 3 h on the volar arm of human subjects, SFA only caused a slight irritation and increase in TEWL. The diffusion lag times of HN were reduced by the application SFA to the same extent as and not more than by the application of the pure solvent PG. In contrast, the application of UFA caused a significant increase in TEWL and LDV (irritation) responses. The TEWL values after oleic acid application were higher than those observed for the other three acids, while the irritation potential of arachidonic acid was the highest among UFA. As with SFA, sites treated with UFA did not show significantly different lag times of HN diffusion from PC-treated sites. The data suggest that the degree of irritation and the degree of barrier modulation for fatty acids are not necessarily correlated.

Three Etiologic Facets of Dandruff and Seborrheic Dermatitis: Malassezia Fungi, Sebaceous Lipids, and Individual Sensitivity

“…The vehicle chosen for dosing of OA (propylene glycol 50%, ethanol 30%, and water 20%) was selected to minimize the potential for increasing Malassezia numbers (Faergemann, 2000). The lack of response of non-susceptible individuals is particularly noteworthy, in that another report (Tanojo et al, 1998) showed significant barrier disruption effects from a slightly higher dose of OA in a similar vehicle. Our result strongly supports that dandruff sufferers display an underlying difference in permeability barrier function, relative to non-dandruff individuals, that renders them more susceptible to fatty acid-induced barrier disruption.…”

“…Further, in order to preclude inadvertently increasing the number of Malassezia, the OA (a known Malassezia carbon source as well as metabolite) was dosed in an anti-microbial vehicle containing 50% propylene glycol (Faergemann and Fredriksson 1980;Faergemann, 2000). Propylene glycol has previously been used as a carrier for fatty acids used in human skin barrier studies (Tanojo et al, 1998).…”

Human sebum extract induces barrier disruption and cytokine expression in murine epidermis

“…Potts et al [18] demonstrated that oleic acid (OA) can increase the skin water permeability, which may due to the formation of permeable interfacial defects and in turn creates a separate phase within SC lipids. Moreover, topical application of unsaturated fatty acid on human forearm was more effective in enhancing TEWL and more irritating than saturated fatty acid [19]. Choi et al [20] and Jiang et al [21] reported that repeated OA treatment on hairless mouse skin induced chronic skin barrier impairment, including increased TEWL, abnormalities of SC lipid bilayer, lacunar dilatation, as well as loss of epidermal basal layer's calcium gradient.…”

Development of an Amphiphilic Chitin Derivative with Lipid/Peptide-Type Side Chains Having Skin Protective Ability

“…Generally speaking, n-hexadecane, oleic acid and SDS are accepted skin barrier-disturbing agents known to cause irritation. 40 After pretreatment with DGC or WSC, each irritant was applied to hairless mouse skin (Tables 3-5). Because the purpose of this experiment was to compare protective skincare efficacy between DGC and WSC, a lower density (0.6wt%) of DGC and WSC was used compared with the above-mentioned test concentration (1.0wt%) aimed at curative skincare.…”