The multifunctional role of ectoine as a natural cell protectant.

The protective properties of ectoine, formerly described for only extremophilic microorganisms, can be transferred to human skin. Our present data show that the compatible solute ectoine protects the cellular membrane from damage caused by surfactants. Transepidermal water loss measurements in vivo suggest that the barrier function of the skin is strengthened after the topical application of an oil in water emulsion containing ectoine.

In vitro testing to assess the UVA protection performance of sun care products.

The UVA protection delivered by sunscreens is an issue of increasing importance due to the increasing knowledge about UVA-induced skin damage. In Europe there is no officially accepted method available to determine the degree of UVA protection. Therefore, the objective of the present study was to design a protocol combining the merits of an in vitro model, which are simple and reproducible, with aspects known to be relevant from in vivo studies.

Synergy effects between organic and inorganic UV filters in sunscreens.

The influence of the synergy effects between organic and inorganic UV filter substances on the sun protection factor (SPF) of topically applied sunscreen formulations is investigated. The medium is considered to have reflection, absorption, and scattering properties. The distribution of photons in this medium is investigated by Monte Carlo calculation.

Ectoin: an effective natural substance to prevent UVA-induced premature photoaging.

With the help of a new 'UVA stress model', it was shown that Ectoin protects the skin from the effects of UVA-induced cell damage in a number of different ways. Using cell cultures, high-performance thin-layer chromatography, gel electrophoresis mobility shift assays, reverse transcriptase polymerase chain reaction, ion exchange chromatography and UV spectroscopy, it was demonstrated that the UVA-induced second messenger release, transcription factor AP-2 activation, intercellular adhesion molecule-1 expression and mitochondrial DNA mutation could be prevented. The results obtained clearly demonstrate that Ectoin counteracts the effects of UVA-induced and accelerated skin aging at different cell levels.

Broad-spectrum sunscreens offer protection against urocanic acid photoisomerization by artificial ultraviolet radiation in human skin.

Cis-urocanic acid (UCA) has been indicated as an important mediator of ultraviolet (UV)-induced immunosuppression. In this study we describe a rapid, noninvasive method for the determination of the protective capacity of various sunscreens against the UV-induced isomerization of trans-UCA into its cis form. For this purpose we applied sunscreens prior to in vivo exposure of human volunteers with single or repeated broadband UVB irradiations of 100 mJ per cm2.