Mack Correa Mary Catherine, Mao Guangru, Saad Peter, Flach Carol R, Mendelsohn Richard, Walters Russel M
Johnson & Johnson Consumer Companies, Inc., Newark, NJ, USA.
Exp Dermatol. 2014 Jan;23(1):39-44. doi: 10.1111/exd.12296.
Plant-derived oils consisting of triglycerides and small amounts of free fatty acids (FFAs) are commonly used in skincare regimens. FFAs are known to disrupt skin barrier function. The objective of this study was to mechanistically study the effects of FFAs, triglycerides and their mixtures on skin barrier function. The effects of oleic acid (OA), glyceryl trioleate (GT) and OA/GT mixtures on skin barrier were assessed in vivo through measurement of transepidermal water loss (TEWL) and fluorescein dye penetration before and after a single application. OA's effects on stratum corneum (SC) lipid order in vivo were measured with infrared spectroscopy through application of perdeuterated OA (OA-d34 ). Studies of the interaction of OA and GT with skin lipids included imaging the distribution of OA-d34 and GT ex vivo with IR microspectroscopy and thermodynamic analysis of mixtures in aqueous monolayers. The oil mixtures increased both TEWL and fluorescein penetration 24 h after a single application in an OA dose-dependent manner, with the highest increase from treatment with pure OA. OA-d34 penetrated into skin and disordered SC lipids. Furthermore, the ex vivo IR imaging studies showed that OA-d34 permeated to the dermal/epidermal junction while GT remained in the SC. The monolayer experiments showed preferential interspecies interactions between OA and SC lipids, while the mixing between GT and SC lipids was not thermodynamically preferred. The FFA component of plant oils may disrupt skin barrier function. The affinity between plant oil components and SC lipids likely determines the extent of their penetration and clinically measurable effects on skin barrier functions.
由甘油三酯和少量游离脂肪酸（FFA）组成的植物源油脂常用于护肤方案中。已知FFA会破坏皮肤屏障功能。本研究的目的是从机制上研究FFA、甘油三酯及其混合物对皮肤屏障功能的影响。通过测量单次涂抹前后的经表皮水分流失（TEWL）和荧光素染料渗透情况，在体内评估油酸（OA）、三油酸甘油酯（GT）和OA/GT混合物对皮肤屏障的影响。通过应用全氘代油酸（OA-d34），利用红外光谱法在体内测量OA对角质层（SC）脂质有序性的影响。OA和GT与皮肤脂质相互作用的研究包括用红外显微光谱法在体外对OA-d34和GT的分布进行成像，以及对水单层中混合物进行热力学分析。单次涂抹后24小时，油混合物以OA剂量依赖性方式增加了TEWL和荧光素渗透，纯OA处理的增加幅度最大。OA-d34渗透到皮肤中并使SC脂质无序化。此外，体外红外成像研究表明，OA-d34渗透到真皮/表皮交界处，而GT仍留在SC中。单层实验表明OA与SC脂质之间存在优先种间相互作用，而GT与SC脂质之间的混合在热力学上并不占优势。植物油中的FFA成分可能会破坏皮肤屏障功能。植物油成分与SC脂质之间的亲和力可能决定了它们的渗透程度以及对皮肤屏障功能的临床可测量影响。
