Stabilization of microtubules restores barrier function after cytokine-induced defects in reconstructed human epidermis.

Background: A variety of human skin disorders is characterized by defects in the epidermal barrier, leading to dehydration, itchiness, and rashes. Previously published literature suggests that microtubule stabilization at the cortex of differentiating keratinocytes is necessary for the formation of the epidermal barrier.

Objectives: We tested whether stabilization of microtubules with paclitaxel or epothilone B can repair barrier defects that were experimentally induced in three-dimensional culture models of epidermis.

Cathepsin S, a new pruritus biomarker in clinical dandruff/seborrhoeic dermatitis evaluation.

Dandruff/seborrhoeic dermatitis (D/SD) is characterized by Malassezia colonization, impaired barrier function with subsequent inflammation, resulting in dandruff and itching. Histamine is one of the biomarkers of pruritus now widely used in treatment efficacy trials. The exact mechanism leading to histamine release and pruritus is not yet clear.

Clinical and biochemical assessment of maintenance treatment in chronic recurrent seborrheic dermatitis: randomized controlled study.

Introduction: Few studies have investigated the long-term effects of a maintenance regimen in the prevention of relapses in scalp seborrheic dermatitis (SD), in particular following biomarker changes.

Materials And Methods: A new shampoo containing beta-glycyrrhetinic acid (18βGA) in addition to cyclopiroxolamine (CPO) and zinc pyrithione (ZP) was tested in 67 subjects suffering from SD with moderate to severe erythema and itching in a biphasic study. After a first common intensive treatment phase (investigational product thrice a week × 2 weeks), subjects randomly received the investigational product once a week × 8 weeks (maintenance) or a neutral shampoo (discontinuation) in a comparative, parallel group maintenance phase.

Slow internal release of bioactive compounds under the effect of skin enzymes.

A new strategy for the skin delivery of bioactive compounds has been developed, using enzymes involved in the maintenance of the epidermal barrier function and the enzymatic transformation of corresponding precursors. This new strategy has been tested with regard to two enzymatic activities of the skin barrier: extracellular glucosidase and esterase/lipase. An analysis of the requirements for the glycosidic bond hydrolysis of any glycoconjugate by beta-glucocerebrosidase indicates that the release of the moiety linked to the glucose unit is obtained as long as the glycosidic bond being broken is not hindered, and as long as the leaving group property of the released moiety is good enough.

Selective inhibition of Fe- versus Cu/Zn-superoxide dismutases by 2,3-dihydroxybenzoic acid derivatives.

A series of catechol derivatives were synthesised and tested for their ability to inactivate the iron-containing superoxide dismutase (Fe-SOD) from Escherichia coli and the bovine erythrocytes Cu/Zn-SOD. Incubation of catechols with Fe- or Cu/Zn SODs resulted in a time-dependent loss of enzyme activity with highly selective inhibition for the iron-dependent enzyme. Catechol-induced inactivation of SODs was correlated with the auto-oxidation of the catechol compounds to their corresponding ortho-quinone derivatives, which was found to be non-dependent on the presence of enzymes.