Dorothee Dähnhardt(1), Stephan Dähnhardt-Pfeiffer(1), Isabel Simon(2), Dana Ditgen(3), Inge Holland(2), Dörte Segger(3), Jürgen Blaak(2), Peter Staib(2)

1. Microscopy Services Dähnhardt GmbH, Flintbek, Germany
2. Research & Development and Regulatory Affairs, Kneipp GmbH, Wuerzburg, Germany
3. SGS INSTITUT FRESENIUS GmbH, Hamburg, Germany

In the wake of ever-increasing environmental pollution, human skin in the modern urban world is exposed to increased levels of harmful environmental pollutants. Many studies have shown that these pollutants can weaken the epidermal skin barrier and thus facilitate the penetration of these substances into the skin. An important goal of modern skin care against harmful environmental influences should therefore be to protect and strengthen the epidermal barrier and to repair occurring damage quickly and efficiently.

With this in mind, in the present study we investigated what damage cigarette smoke causes to the epidermal barrier and 1) whether the regular application of a O/W emulsion (Day Cream) can protectively strengthen the epidermal barrier against environmental damage and 2) whether a cigarette smoke-induced disruption of the epidermal barrier is restored faster and better by the regular application of a another O/W emulsion (Night Cream) than in product-untreated skin.

The two products are slightly different in plant-oil, active ingredient composition and texture. Firstly, the study has shown that the Lipbarvis® method is suitable for measuring the effect of cigarette smoke, in contrast to conventional biophysical measurement methods (transepidermal water loss, skin hydration). Secondly, both products were able to improve skin barrier function in the corresponding test scenario. This was demonstrated for both test products by a significantly reduced TEWL, significantly increased skin hydration and significantly improved length of the lipid lamellae in the intercellular space, as well as the protective effect of the day cream on the epidermal skin barrier and the regenerative properties of the tested night cream.

1) TEM images of the intercellular lipid lamellae in the intercellular space of the stratum corneum before (a) and after two weeks and a single smoke exposure of the product-untreated test site (b) and the Day Cream-treated test site (protective study design) (c). The lipid lamellae in the intercellular space are coloured orange, while areas with little to no lipid lamellae are coloured blue. The corneocytes adjacent to the intercellular space are stained dark brown.

2) TEM images of the intercellular lipid lamellae in the intercellular space of the stratum corneum before (a) and after smoke exposure (b) followed by two product-untreated weeks (c) as well as two weeks of product treatment with Night Cream (regenerative study design) (d). The lipid lamellae in the intercellular space are coloured orange, while areas with little to no lipid lamellae are coloured blue. The corneocytes adjacent to the intercellular space are stained dark brown.

3) Scanning electron micrograph of a silicone print of the skin surface after expo- sure to smoke. Left image shows the tar film on the skin after smoke exposure, right im- age shows the skin surface without smoke exposure.

*publirédactionnel

CONTACT

Dorothee Dähnhardt – ddaehnhardt@microscopy-consulting.com

Jürgen Blaak – juergen.blaak@babor.de

Peter Staib – peter.staib@kneipp.de

https://www.microscopy-services.com/en/