Abstract
The influence of a topically applied formulation containing components of natural moisturizing factor (NMF) on barrier-related parameters of the stratum corneum (SC) was investigated in vivo using confocal Raman microspectroscopy in a randomized, placebo-controlled double-blind study on 12 volunteers for 14 days. This method allowed for the elucidation of subtle differences between the verum and the placebo even though the components of the verum naturally occur in the SC. This differentiation is not possible non-invasively by conventional methods. In this study, we found that the applied verum and placebo formulations disrupted the equilibrium of water, NMF and lipids in the SC. The adverse effects of the formulation could be mitigated by incorporating it into a simplified supplementation of NMF molecules. As a long-term effect, the amount of strongly bound water increases at 30–40% SC depth (p < 0.05) and the amount of weakly bound water decreases at 30–40% SC depth (p < 0.05) for the verum. This supplement was also unexpectedly able to prevent intercellular lipids (ICL) disorganization in selected depths. In the long term, the verum treatment limited the lateral disorganization of the ICL to the upper 20% SC depth. Further research is required to elucidate the interplay of these factors in the SC, to better understand their contribution to the equilibrium and barrier function of the skin. This understanding of the interaction of these naturally occurring components could help in the future to develop and optimize topical treatments for diseases like psoriasis, atopic dermatitis, ichthyosis where the skin barrier is disrupted.
Highlights
The skin barrier function plays an important role in the regulation of the cutaneous hydration status and controls the penetration of xenobiotics [1,2,3,4]
We found that the applied verum and placebo formulations disrupted the equilibrium of water, natural moisturizing factor (NMF) and lipids in the stratum corneum (SC)
The adverse effects of the formulation could be mitigated by incorporating it into a simplified supplementation of NMF molecules
Summary
The skin barrier function plays an important role in the regulation of the cutaneous hydration status and controls the penetration of xenobiotics [1,2,3,4]. Several skin barrier related parameters, characterizing the ICL organization [11], water binding properties [25], folding of keratin [32] and NMF content [37,38,39] were determined depth dependently in the SC using in vivo confocal Raman microspectroscopy. It has been shown, that these parameters are inhomogeneous, exposing a maximal lipid ordering in the depth 20–40% of the SC thickness, which correlates with the NMF content and the hydrogen bonding state of water. The measurements were performed 1 h, 4 h, 7 and 14 days after the beginning of the daily treatment, in order to examine short-term and long-term effects of increased water binding capabilities to the skin barrier related parameters
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
