Skin pharmacology : the official journal of the Skin Pharmacology Society最新文献

Effective methods of fungal treatment involve reduction in fungal infections and host inflammatory responses. Naftifine (NF), a topical antifungal agent, is highly active in vitro and in vivo against a wide range of pathogenic fungi. Additionally NF has been shown to inhibit polymorphonuclear leukocyte (PMN) chemotaxis and respiratory burst activity in an irreversible dose-dependent and time-dependent manner. Since leukocyte adherence to endothelia is believed to be one of the initial crucial events in the recruitment of circulating leukocytes to the site of inflammation, we have investigated the in vitro effect of NF on PMN adherence to nylon fiber, BSA-coated glass chamber or polystyrene, and endothelial monolayers via three adherence assays. All three assays demonstrated a statistically significant reduction (p < 0.01-0.001) in PMN adherence to the respective media. In particular, NF (at 30-60 micrograms/ml) significantly inhibited PMN adherence to endothelial monolayers (p < 0.01) as measured spectrophotometrically by the uptake of rose bengal stain. Therefore, NF inhibits PMN adherence to endothelia in our in vitro model system. This inhibition may constitute part of the anti-inflammatory effect of NF.

Copper and zinc percutaneous absorptions were assessed in vitro using sliced human skin and both petrolatum and hydrophilic gels as vehicles. Applied quantities were largely in excess for the duration of the experiment (72 h). The absorption of sulphates and chlorides was compared. The cumulated amount recovered in receptor fluid was below 50 micrograms/cm2. The apparent permeability constant values kept in the range of 10(-6) cm h-1, except for ZnCl2 in gel vehicle (2.9 10(-5) cm h-1). With the exception of CuCl2 in gel vehicle, chlorides gave higher absorption rates than sulphates. This can be related to the higher octanol-water partition coefficient of chlorides. Storage within the epidermis was found to be equal to or greater than, and within the dermis equal to or lower than the 72 hour cumulative amount in receptor fluid. No difference was found in this respect between copper an d zinc. This work confirms the poor absorption of electrolytes through normal human skin, whatever the vehicle used.

Comparative testing of seven wound dressings (WD) has been performed with human HaCaT keratinocyte and mouse 3T3 fibroblast cultures. To assess biocompatibility, morphologic examinations were combined with cell counting. Supernatants were subjected to measurements of tissue peptide antigen (TPS), soluble intercellular adhesion molecule 1 (ICAM-1), and interleukins (IL-1 alpha, -1 beta, -6). Furthermore, monoxygenation, the reduced glutathione/oxidized gluthathione (GSH/GSSG) ratio and lipid peroxides were determined. Initial morphologic events were noted within the first day of exposure to WD. After 72 h, inhibition of cell growth was observed in the presence of hydrocolloids and hydrogels. The cytochrome-P-450-dependent ethoxyresorufin 0-deethylation rate and the GSH/GSSG ratio were not altered by WD in HaCaT cells. Lipid peroxide generation, IL-1 and ICAM-1 were scarcely detectable. TPS and IL-6 release indicate the presence of an 'activated stage' of keratinocytes and fibroblasts exposed to WD. Peptide release in vivo may contribute to the beneficial effects of modern dressings in the treatment of superficial cutaneous wounds.

Background and design: Benzoic acid (BA) was used to induce nonimmunologic contact irritation in 10 younger (23-47 years old) and 5 older (72-90 years old) healthy volunteers. BA 2.5% in petrolatum was applied to 8 locations on the face, neck and volar forearm. Changes in the skin blood flow were monitored using a laser Doppler flowmeter. Also measured at each location were baseline measurements of skin blood flow, transepidermal water loss, stratum corneum hydration, skin surface temperature and skin surface pH.

Results: The neck area exhibited the greatest reaction in both age groups while the forearm exhibited the least. At each site tested, the younger group consistently demonstrated greater reactivity to BA. A significant correlation was noted between stratum corneum hydration and irritation.

Conclusions: This information provides a basis to further study the frequent poorly understood intolerance of the face to topical formulation.

Cyclosporine A (CyA), a well established treatment of psoriasis, is a highly lipophilic cyclic undecapeptide mainly used for its immunosuppressive properties and exerting a wide spectrum of biological activities including fungicidal antiproliferative and anti-inflammatory effects. Plasminogen activators (PA), urokinase (UK, M(r) 55,000) and tissue type plasminogen activators (tPA, M(r) 74,000), physiologically catalyze the conversion of the plasminogen to the wide spectrum proteinase plasmin. UK and tPA are involved in cell growth, differentiation and migration. It has recently been shown that psoriatic epidermis is provided with abnormal tPA-dependent PA activity and that in lesional epidermis elevated tPA mRNA levels are present. It has been suggested that the tPA-dependent PA activity is a marker of disease activity and is reversible with different topical and systemic treatments. In this preliminary study we investigate the effect of CyA on the tPA mRNA transcription on A431 keratinocytes cell line. Subconfluent A431 cell cultures have been treated with CyA at in vivo relevant concentrations (10, 7.5, 5 micrograms/ml) for 48 h. Northern blot analysis of total RNA extracted from cultured A431 cell line has been performed for detecting tPA mRNA. mRNA for tPA has been detected in the control samples whereas an evident decrease of tPA mRNA expression has been detected in the CyA-treated samples. These data suggest that CyA could have an effect in clearing psoriatic lesions also modulating the abnormal plasminogen activation i.e. tPA-dependent serinoproteinase activity.

Percutaneous absorption and cutaneous bioavailability of zinc and copper from zinc 2-pyrrolidone 5-carboxylate (ZnPC), zinc oxide (ZnO), zinc sulfate (ZnSO4), copper 2-pyrrolidone 5-carboxylate (CuPC) and copper sulfate (CuSO4) were compared using 5 formulations (3 emulsions and 2 ointments) that were applied topically on human skin in vitro. After application for 72 h, percutaneous absorption of zinc from ointments containing ZnO and ZnSO4 was found to be lower than that from a ZnPC-containing emulsion (0.36 and 0.34 versus 1.60% of applied dose). In the case of copper, the flux after a 72-hour treatment period showed that there had been minimal release from CuPC- and CuSO4-containing formulations (approximately 5 ng/cm2/h). All formulations used in this study effected an increase in zinc and copper concentrations in whole skin and epidermis. Bioequivalence of the 5 formulations based on pharmacokinetic results was assessed, and salt and vehicle effects were discussed.

Fumaric acid, fumaric acid dimethylester, and the dithranol derivative C4-lactone were studied in the mouse tail test to evaluate their effects on epidermal cell differentiation compared with other topical antipsoriatic drugs, such as betamethasone, calcipotriol, and dithranol. Mouse tails were treated for 2 weeks and longitudinal histological sections prepared of the tail skin. The length of the orthokeratotic regions (stratum granulosum) was measured on 10 sequential scales per tail and expressed as percentage of the full length of the scale. In addition, epidermal thickness was measured and the efficacy of the various compounds evaluated. In comparison to 2% salicylic acid ointment, all tested compounds except fumaric acid significantly (p < or = 0.05) increased the proportion of the orthokeratotic region. C4-lactone and calcipotriol were less effective than dithranol, fumaric acid dimethylester only moderately influenced cell differentiation, and betamethasone showed the least potent effect. Dithranol was the most potent substance inducing orthokeratosis without increasing epidermal thickness.

The in vitro/in vivo difference in enhanced skin permeation of nicardipine hydrochloride (NC) by simultaneous use of 1-menthol and ethanol (MEW system, 1-menthol:ethanol:water = 5:40:55) was investigated in hairless rats. First, the cutaneous blood flow clearance (clearance from skin to blood flow) of NC per unit area of skin (CLCB/A), which was comparable to the permeability coefficient across skin (PC), was calculated from intracutaneous and intravenous injection data using the deconvolution method; the value was 1.67 microliters/h/cm2. Two formulations containing NC and the MEW system, solution (SOL) and 15% hydroxypropyl cellulose gel (GEL), were used for in vitro and in vivo permeation experiments. The in vitro PC of NC via excised skin from SOL (23.3 microliters/h/cm2) was significantly higher than CLCB/A, and that from GEL (1.48 microliters/h/cm2) was similar to CLCB/A. Consequently, the steady-state concentration of NC in skin during in vivo application of SOL was 6.6 times higher than corresponding in vitro data. In vivo PCs from SOL and GEL were however significantly lower than CLCB/A. These results may be explained by the findings, using a laser Doppler flowmeter, that cutaneous blood flow was decreased by the application of MEW.

FK 506 and cyclosporin A (CyA) are two immunosuppressive drugs which are known to be effective in the treatment of psoriasis by inhibiting the activation of T cells. In contrast, their influence on the proliferation of keratinocytes is discussed controversially. The second messenger cyclic adenosine monophosphate (cAMP) has been regarded as a regulator for cell growth and proliferation for 20 years. Hyperproliferation of many cells and particularly of psoriatic keratinocytes was speculated to be due to a decrease in cAMP levels in the psoriatic epidermis, whereas new findings could not confirm these observations. To clarify this discussion we determined the intracellular cAMP content in isoprenaline-stimulated keratinocytes from psoriatics and controls after treatment with CyA or FK 506. Ethanol and the beta-blocking drug propranolol served as controls. The basal level of cAMP and the response to isoprenaline in psoriatic keratinocytes did not differ from those of controls. CyA dramatically reduced the cAMP level and FK 506 just slightly diminished it in a dose-dependent manner. Both drugs diminished the cAMP level more effectively in the keratinocytes from lesional psoriatic skin than in keratinocytes from controls. These data provide evidence that CyA influences early signal transduction pathways by depressing the intracellular cAMP in keratinocytes. This supports the view of other groups that CyA and perhaps also FK 506 influence not only immuno-competent cells but also keratinocytes in the treatment of psoriasis. Furthermore, it is doubtful that a low cAMP level is a positive regulator for cell growth and the hyperproliferation of psoriatic keratinocytes.

Although retinoids may exert their action via binding to nuclear retinoic acid receptors (RARs), other mechanisms of action are not excluded. For example, the anti-acne drug, isotretinoin, lacks affinity for the receptors, but is a very potent inhibitor of endogenous vitamin A metabolism in human epidermal cells. To further extend this observation, we studied the effect of 12 different retinoids on the metabolism of [3H]retinol ([3H]ROH) in HeLa cells, previously shown to produce constant levels of 3,4-didehydroretinol (ddROH). The cells were cultured in the presence of the unlabeled retiniods for 20 h, followed by 4 h incubation with [3H]ROH. The accumulation of [3H]ROH and [3H]ddROH in cellular extracts was analysed by HPLC. Addition of 10(-10) to 10(-5) M of four naturally occurring isomers of retinoic acid caused a 4- to 6-fold increase in [3H]ROH accumulation and an 80% decrease in [3H]ddROH. Addition of synthetic retinoids with a terminal carboxyl (CD270, CD271, CD367 and Ro 13-7410) decreased the [3H]ddROH accumulation with about 70%, but hardly at all affected the accumulation of [3H]ROH. We conclude that cultured HeLa cells appear to be useful for screening retinoids for their effects on vitamin A metabolism showing that a terminal carboxylic acid is a prerequisite for any major effects on metabolism to occur. Whether this effect is due to interaction with RARs or to competitive inhibition of vitamin-A-metabolizing enzymes demands to be studied.