Hybrids between H2S-donors and betamethasone 17-valerate or triamcinolone acetonide inhibit mast cell degranulation and promote hyperpolarization of bronchial smooth muscle cells.

Glucocorticoids represent the standard gold treatment of inflammation in asthmatic patients. More recently, H2S has been described to exert positive effect on this disease. Bearing in mind that an improved pharmacological activity and a reduced toxicity can be obtained through hybridization of different molecules, simultaneously modulating multiple targets, we designed and synthesized novel betamethasone 17-valerate and triamcinolone acetonide hybrids with well-known H2S-donor moieties. Synthesized compounds have been evaluated for the potential H2S-releasing profile both in cell-free environment and into the cytosol of bronchial smooth muscle cells (BSMCs). The two hybrids 4b and 5b were investigated by molecular modelling studies and results indicated that the steric accessibility of the isothiocyanate carbon atom can account for their different H2S releasing properties. Furthermore, the most promising derivatives 4b and 5b have been tested for inhibitory effect on mast cell degranulation and for the ability to induce cell membrane hyperpolarization in BSMCs. Significant inhibitory effect on mast cell degranulation was assessed, resulting to reduce ß-hexosaminidase release more efficiently than the corresponding native drugs. Both compounds determined a massive membrane hyperpolarization of BSMCs and proved to be 4-fold more effective compared to reference compound NS1619. These effects represent an enrichment of the pharmacological activity of the native drugs.

Topical Betamethasone Valerate As a Prophylactic Agent to Prevent Acute Radiation Dermatitis in Head and Neck Malignancies: A Randomized, Open-Label, Phase 3 Trial.

PURPOSE: We assessed the role of topical betamethasone as a prophylactic agent in patients receiving radiation for head and neck malignancies. METHODS AND MATERIALS: This randomized, open-label, phase 3 trial was completed at a single research institute. Patients receiving curative radiation for head and neck cancer were randomized into 2 groups of 75 patients each by computer-generated permuted block random assignment. Patients in the test arm applied 0.1% topical betamethasone valerate cream once a day, after radiation. Patients in the control arm received best supportive care. The Radiation Therapy Oncology Group acute toxicity grading scale was used to assess radiation dermatitis after every fifth fraction until completion and at 2 weeks after treatment. Primary outcome in both arms was the proportion of patients who developed grade 2 and 3 acute skin reaction. The trial is registered at the Central Trial Registry of India (CTRI/2017/04/008298). RESULTS: Between April 15, 2017, and October 30, 2018,150 patients were randomized into the study, with 75 patients in each arm. Fourteen patients in the test arm and 15 patients in the control arm did not complete the intended treatment. Per the intention-to-treat analysis, 25 of 75 patients (33.3%) and 38 of 75 patients (50.7%) developed grade 2 or greater radiation dermatitis in the test and control arms, respectively (absolute difference, 17.4%; 95% confidence interval, 4%-30%; P = .032). Fifteen of 75 patients (20%) developed grade 3 reactions in the test arm compared with 18 of 75 patients (24%) in the control arm (absolute difference, 4%; 95% confidence interval, 7%-15%; P = .554). CONCLUSION: Although prophylactic use of betamethasone significantly reduced the composite outcome of the proportion of patients developing grade 2 and grade 3 radiation dermatitis, it did not reduce the proportion of patients developing the clinically significant outcome of grade 3 radiation dermatitis.

The vitamin D3 analog, maxacalcitol, reduces psoriasiform skin inflammation by inducing regulatory T cells and downregulating IL-23 and IL-17 production.

BACKGROUND: Psoriasis is a Th1/Th17-mediated inflammatory dermatosis treated with topical corticosteroids and vitamin D3 analogs (VD3 As). OBJECTIVE: To compare the effects of a VD3 A maxacalcitol and betamethasone valerate (BV) steroid lotion on topical imiquimod (IMQ)-induced psoriasiform skin inflammation. METHODS: Female BALB/c mice were treated with vehicle, maxacalcitol or BV lotion on the skin for 3 days, and IMQ cream for 6 days. q-PCR, H&E, immunohistochemistry and immunofluorescence studies were performed on skin samples. Additionally, mice were treated with vehicle, maxacalcitol or BV lotion for 3 days and CD4+CD25+ regulatory T cells (Tregs) and CD4+CD25- cells from each group were isolated from lymph nodes. Adoptive transfer of the cells was performed on recipient mice which were treated with IMQ cream for 6 days, and skin samples were obtained for q-PCR and H&E staining. RESULTS: Maxacalcitol and BV were comparable in regards clinical improvement, although maxacalcitol reduced the MHC Class II+ inflammatory cell infiltration more than BV in IMQ skin. While both treatments downregulated IL-17 A, IL-17 F, IL-22, IL-12p40, TNF-α and IL-6 mRNA expression levels, only maxacalcitol downregulated IL-23p19 expression. Significantly increased Foxp3+ cell infiltrations and IL-10 expression were noted in maxacalcitol-treated IMQ skin. Adoptive transfer of Treg cells from maxacalcitol-treated donor mice improved IMQ-induced inflammation clinically and histopathologically more than the recipients of Treg cells from BV-treated donor groups, showing reduced levels of inflammatory cytokines and increased IL-10 expression. CONCLUSION: These results indicate that maxacalcitol reduces psoriasiform skin inflammation by inducing Treg cells as well as downregulating IL-23 and IL-17 production.

Targeting PRPK and TOPK for skin cancer prevention and therapy.

Solar ultraviolet (sUV) irradiation is a major environmental carcinogen that can cause inflammation and skin cancer. The costs and morbidity associated with skin cancer are increasing, and therefore identifying molecules that can help prevent skin carcinogenesis is important. In this study, we identified the p53-related protein kinase (PRPK) as a novel oncogenic protein that is phosphorylated by the T-LAK cell-originated protein kinase (TOPK). Knockdown of TOPK inhibited PRPK phosphorylation and conferred resistance to solar-simulated light (SSL)-induced skin carcinogenesis in mouse models. In the clinic, acute SSL irradiation significantly increased epidermal thickness as well as total protein and phosphorylation levels of TOPK and PRPK in human skin tissues. We identified two PRPK inhibitors, FDA-approved rocuronium bromide (Zemuron®) or betamethasone 17-valerate (Betaderm®) that could attenuate TOPK-dependent PRPK signaling. Importantly, topical application of either rocuronium bromide or betamethasone decreased SSL-induced epidermal hyperplasia, neovascularization, and cutaneous squamous cell carcinoma (cSCC) development in SKH1 (Crl: SKH1-Hrhr) hairless mice by inhibiting PRPK activation, and also reduced expression of the proliferation and oncogenesis markers, COX-2, cyclin D1, and MMP-9. This study is the first to demonstrate that targeting PRPK could be useful against sUV-induced cSCC development.

Inhibitory effects of UV-based therapy on dry skin-inducible nerve growth in acetone-treated mice.

BACKGROUND: UV-based therapy has anti-pruritic effects in inflammatory skin diseases, such as atopic dermatitis and psoriasis. These anti-pruritic effects may be partly due to inhibition of intraepidermal nerve growth, but they have not been fully characterized. OBJECTIVE: This study was performed to characterize the anti-nerve growth effects of UV-based therapies in acetone-treated mice as an acute dry skin model. METHODS: Nerve fibers penetrate into the epidermis 24h after acetone treatment in mice, and nerve growth peaks 48h after acetone treatment. To investigate the effects of UV-based therapies on the epidermal nerve fibers, including combination treatment with corticosteroid ointment, the mice were treated with psoralen ultraviolet A (PUVA), PUVA and betamethasone valerate ointment (PUVA+BV), narrowband ultraviolet B (NB-UVB), or an excimer lamp. Each therapy was provided 24h after acetone treatment, and skin samples were taken 48h later. Nerve fiber densities and expression levels of nerve growth factor (NGF) and semaphorin 3A (Sema3A) in the epidermis were examined by immunohistochemistry. RESULTS: Penetration of nerve fibers into the epidermis was observed in the acetone-treated mice, concomitant with increased NGF and decreased Sema3A levels in the epidermis. The acetone-induced intraepidermal nerve growth was significantly decreased by PUVA, PUVA+BV, NB-UVB, and excimer lamp treatments compared with controls. In addition, PUVA+BV and NB-UVB normalized the abnormal expression of NGF and Sema3A in the epidermis, but no such normalization was observed with excimer lamp treatment. CONCLUSION: UV-based therapies, especially NB-UVB and excimer lamp treatments, may be effective therapeutic methods for pruritus involving epidermal hyperinnervation.

Possible involvement of 5-lipoxygenase metabolite in itch-associated response of mosquito allergy in mice.

This study investigated endogenous mediators involved in mosquito allergy-associated itching in mice. An intradermal injection of an extract of mosquito salivary gland elicited marked scratching in sensitized mice. The 5-lipoxygenase inhibitor zileuton (100 mg/kg), the 5-lipoxygenase activating peptide inhibitor MK-886 (10 mg/kg), and the glucocorticoid betamethasone 17-valerate (3 mg/kg) inhibited the scratching. The scratching was not affected by the cyclooxygenase inhibitors indomethacin and ketoprofen, the TP prostanoid receptor antagonist SQ-29548, the leukotriene B(4) antagonist ONO-4057, the cysteinyl leukotriene antagonist pranlucast, the leukotriene D(4) antagonist MK-571, the platelet-activating factor antagonist CV-3988, the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester, the H(2) histamine-receptor antagonist cimetidine, the H(1) histamine-receptor antagonist terfenadine plus cimetidine, and cypoheptadine that blocks the 5-HT(1/2) serotonin receptors. Zileuton (100 mg/kg) inhibited the increased activity of the cutaneous nerve branch induced by an intradermal injection of the extract, suggesting the peripheral action. Zileuton and MK-886 (10 and 100 microM) did not affect high K(+)-induced increase in intracellular Ca(2+) concentration in cultured dorsal root ganglion neurons. The results suggest that 5-lipoxygenase metabolite(s) other than leukotriene B(4) and cysteinyl leukotrienes are involved in mosquito allergy-associated itching.

The cannabinoid CB2 receptor inverse agonist JTE-907 suppresses spontaneous itch-associated responses of NC mice, a model of atopic dermatitis.

JTE-907, N-(benzo[1,3]dioxol-5-ylmethyl)-7-methoxy-2-oxo-8-pentyloxy-1,2-dihydroquinoline-3-carboxamide, is a selective cannabinoid CB2 receptor antagonist/inverse agonist. The anti-pruritic activity of JTE-907 was studied in NC mice with chronic dermatitis, a model of atopic dermatitis. The oral dose of JTE-907 (1 and 10 mg/kg/day), an immunosuppressant agent tacrolimus (1 mg/kg/day) and a glucocorticoid betamethasone 17-valerate (1 mg/kg/day) for 20 days suppressed the spontaneous scratching and cutaneous nerve activity of NC mice. JTE-907 (10, but not 1, mg/kg) and tacrolimus, but not betamethasone, tended to alleviate the dermatitis. Betamethasone inhibited the body weight gain. These results suggest that JTE-907 suppresses spontaneous itch-associated responses of NC mice without adverse effects such as weight loss.

[Development and pre-clinical aspects of pimecrolimus]. / Entstehungsgeschichte und präklinisches Profil von Pimecrolimus.

Pimecrolimus (SDZ ASM 981), an ascomycin derivative, inhibits the phosphatase calcineurin and blocks the production of inflammatory cytokines in T cells. In contrast to corticosteroids, pimecrolimus has a cell selective mode of action, exerting e.g. no effect on dendritic cells, which have a central function in the skin-associated immune system. Pimecrolimus shows less permeation through skin than corticosteroids and tacrolimus which indicates a lower potential for systemic side effects after topical application. In animal models pimecrolimus has a marked dose-dependent anti-inflammatory activity. However, treatment with pimecrolimus does not induce skin atrophy in contrast to corticosteroids. In contrast to tacrolimus, pimecrolimus does not impair the primary immune reaction in the sensitization phase of allergic contact dermatitis and has generally less effect on systemic immune reactions. In summary, the pharmacological profile of pimecrolimus suggests high clinical efficacy together with excellent safety.

The combined effect of topical CX-659S, a novel diaminouracil derivative, with topical corticosteroid on the three types of allergic responses in mice or guinea pigs.

CX-659S ((S)-6-amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-1-phenyl-2,4(1H,3H)-pyrimidinedione), a newly discovered anti-inflammatory compound, exerts inhibitory effects against picryl chloride-, oxazolone-, and dinitrochlorobenzene-induced acute contact hypersensitivity responses (CHRs) characterized by Th1-type reactions. Furthermore, this compound suppressed chronic CHRs characterized by Th2-type reactions, which is well known to mimic many, if not all, events occurring within the lesional skin of patients with atopic dermatitis (AD). The present study was conducted to determine the combined effect of topical CX-659S with topical corticosteroid on immediate type (ITR), late type (LTR), and delayed type hypersensitivity (DTHR) allergic reactions that are involved in AD. An ineffective dose of CX-659S (0.03 mg/ear) combined with betamethasone valerate (BV) significantly potentiated inhibitory activity of BV alone (0.1 micro g/ear and 0.3Shizuokag/ear) on both the ITR and the LTR in mice with the ovalbumin (OVA)-induced biphasic cutaneous reaction. Furthermore, the combined effect of CX-659S with BV was also observed on dinitrochlorobenzene (DNCB)-induced DTHR in guinea pigs. These results indicate that CX-659S has a combined effect with corticosteroids on every ITR, LTR, and DTHR. Proper treatment with corticosteroids for a safe and effective treatment of AD is needed. Thus, the combination therapy of topical CX-659S with topical corticosteroid would be one of the potential approaches for devising a proper treatment with corticosteroids.

Different skin thinning potential of equipotent medium-strength glucocorticoids.

In this study, we investigated the effect of prednicarbate, mometasone furoate and betamethasone 17-valerate on total skin thickness over a treatment period of 6 weeks. The study was conducted as a double-blind, placebo-controlled randomized clinical trial with a confirmatory approach. The influence of these drugs on healthy human skin under non-occlusive conditions was assessed by measuring total skin thickness and epidermal thickness using 20 and 50 MHz sonography, respectively. Epidermal surface structure was evaluated using profilometry. Visual assessment addressed signs of atrophy and formation of telangiectasia. The reduction of total skin thickness induced by prednicarbate was clearly less than that caused by betamethasone 17-valerate and mometasone furoate. Prednicarbate led to a higher degree of skin thinning than vehicle. For technical reasons, epidermal thickness could not be reliably evaluated with 50 MHz sonography. Profilometry did not demonstrate any differences between treatments. Visible signs of atrophy or telangiectasia were detected in two subjects each upon betamethasone 17-valerate and mometasone furoate, but not upon prednicarbate or its vehicle. Prednicarbate is a topical glucocorticoid with an improved benefit/risk ratio, as it causes less skin atrophy than the equipotent betamethasone 17-valerate.

Human epidermal Langerhans' cells are targets for the immunosuppressive macrolide tacrolimus (FK506).

BACKGROUND: The immunosuppressive macrolide tacrolimus (FK506) has been shown to inhibit allergic contact dermatitis in animal models as well as in human beings. More recently, successful treatment of atopic dermatitis with an ointment containing tacrolimus has been reported. OBJECTIVES: We explored the effects of this compound on epidermal Langerhans' cells (LCs), which are known to play an important pathophysiologic role in inflammatory skin diseases. METHODS: The expression of the intracellular FK506 binding protein (FKBP12) was monitored on freshly isolated and cultured epidermal LCs. Phenotyping and functional exploration of LCs treated with different concentrations of tacrolimus and beta-methasone valerate (betaMv) were performed. RESULTS: FKBP12 is expressed in freshly isolated LCs but is lost while they are maturating into mature dendritic cells. Tacrolimus inhibited the expression of IL-2R (CD25) and of the costimulatory molecules CD80 (B7.1) and CD40. Expression of MHC class I and II was also affected, whereas CD86 (B7.2) expression was not altered. In contrast, betaMv strongly increased the expression of CD25. Paradoxically, while decreasing CD40 and MHC class I expression, betaMv significantly increased the expression of MHC class II, CD80, and CD86 on cultured LCs but impaired their allostimulatory activity. Tacrolimus was about 100 times more potent than betaMv at inhibiting LC stimulatory function. CONCLUSION: Tacrolimus can exert immunopharmacologic alterations on LCs, which may account, at least in part, for the therapeutic effect of this compound in eczematous skin diseases.

Differential modulation of transforming growth factor-beta by betamethasone-17- valerate and isotretinoin: corticosteroid decreases and isotretinoin increases the level of transforming growth factor-beta in suction blister fluid.

Retinoids and glucocorticoids are known to have a potential to modulate the expression of transforming growth factor-beta (TGF-beta). We investigated the effect of oral isotretinoin (13-cis-retinoic acid) on the expression of two distinct isoforms of TGF-beta, TGF-beta1 and TGF-beta2, in suction blister fluid and serum in acne patients. We also investigated the effect of topical glucocorticoid (betamethasone-17-valerate) and age on suction blister fluid TGF-beta1 in healthy volunteers. Six weeks of isotretinoin treatment caused a statistically significant 19% increase in suction blister fluid TGF-beta1. The suction blister fluid TGF-beta2 level remained below the sensitivity level of the immunoassay in many cases. Isotretinoin did not affect the serum TGF-beta1 or TGF-beta2 level. Betamethasone-17-valerate pretreatment for 3 days twice a day caused a statistically significant 17% decrease in suction blister fluid TGF-beta1. The active form of TGF-beta1 represented 5% of the total TGF-beta1 in suction blister fluid. Our diffusion calculations suggest that all TGF-beta1 and TGF-beta2 detected in suction blister fluid have diffused from systemic circulation. The increase in suction blister fluid TGF-beta1 after isotretinoin treatment seems to be of local origin, while the decrease in suction blister fluid TGF-beta1 after glucocorticoid pretreatment seems to be due to glucocorticoid-induced vasoconstriction resulting in decreased diffusion of TGF-beta1 from the circulation. Modulation of local interstitial fluid TGF-beta1 concentration may be one mechanism by which isotretinoin and glucocorticoids mediate their effects in skin.

Analysis of chromameter results obtained from corticosteroid-induced skin blanching assay: comparison of visual and chromameter data.

In a Guidance document, the American FDA recommends the use of a Minolta chromameter rather than the human eye for the quantitative assessment of the pharmacodynamic blanching response produced by topical application of corticosteroids. The purpose of this study was to compare the appropriateness of the human eye and two models of chromameter for the estimation of skin blanching, in terms of the quality of the data generated by each method. The corticosteroid-induced skin blanching from four different betamethasone 17-valerate cream formulations was compared in a typical human skin blanching trial. The optimized assay methodology routinely practised in our laboratories was utilized. The blanching responses were assessed visually by three trained, independent observers and recorded by two chromameters (Minolta model CR-200 and model CR-300). The topical availability of the four creams was determined using visual scoring and chromameter measurements. All data were manipulated in such a manner as to produce a blanching response versus time profile from which AUBC analysis could be performed. Good correlation was observed between the visual assessments made by three independent observers. In contrast, moderate correlation was determined between visual, CR-200 and CR-300 measurements. Surprisingly, no direct linear relationship between the AUBCs produced by the two chromameters was observed indicating that the quality of the data obtained from the two instruments may not be equal. This investigation also indicated that the use of the chromameter is not completely objective. Visual scoring and chromameter measurement produce data sets that differ in quality. Each procedure needs to be validated and investigators have to be trained for both visual assessment and the operation of the chromameter, particularly with regard to the manipulation of the measuring head of the instrument.

Local anti-inflammatory activity and systemic side effects of NM-135, a new prodrug glucocorticoid, in an experimental inflammatory rat model.

The local anti-inflammatory activity and systemic side effects of NM-135 (6alpha,9-difluoro-11beta-hydroxy-16alpha-methyl-21[[2 ,3,4,6-tetrakis-O-(4-methylbenzoyl)-beta-D-glucopyranosyl]oxy]-pregna-1, 4-diene-3,20-dione) in croton oil-induced granuloma pouches and ear edema in rats were studied. The local anti-inflammatory activity of NM-135 was stronger than that of betamethasone 17-valerate (BV). As to systemic side effects, BV and diflucortolon valerate (DFV) caused thymolysis at the doses required for the anti-inflammatory activity. In contrast, no clear systemic side effect was observed in rats administered NM-135 at the dose producing the anti-inflammatory activity. These results suggest that NM-135 is a drug exhibiting a high degree of dissociation between the local anti-inflammatory activity and systemic side effects.

Effect of topical tretinoin on non-sun-exposed human skin connective tissue: induction of tenascin but no major effect on collagen metabolism.

The effects of topical tretinoin on collagen synthesis and degradation were studied in 29 volunteers. The subjects applied 0.1% tretinoin cream on their non-sun-exposed abdominal skin once a day for 1 week (n = 10) (experiment 1) or twice a day for 2 weeks (n = 8) (experiment 2) or once a day for 2 months (n = 11) (experiment 3). After the treatments, suction blisters were induced and amino-terminal propeptides of type I and III procollagens (PINP, PIIINP, respectively) (experiments 1 and 3) and carboxy-terminal propeptide of type I procollagen (PICP) (experiment 2) were assayed as an index of de novo collagen synthesis by radioimmunoassays. Matrix metalloproteases 2 (MMP-2) and 9 (MMP-9) were assayed by the zymography method in experiment 2. In experiment 3, histology, immunohistochemistry of type I and III procollagens, tenascin, mRNA levels of type I collagen alpha 1-chain [alpha 1 (I)], interstitial collagenase (MMP-1), MMP-2, MMP-9 by slot-blot analysis and the levels of alpha 1 (I) collagen mRNA by a quantitative polymerase chain reaction method were studied. The proportional area of elastic fibres visualized in Verhoeff-stained sections was analysed by computerized digital image analysis. The results indicated that treatment with topical tretinoin does not markedly induce de novo synthesis of collagen in vivo or affect matrix metalloproteases. In the immunohistochemical staining, tenascin was increased in the papillary dermis. As it has been suggested that tretinoin could counteract the atrophogenic effect of corticoids on the dermis, the effect of a combination of betamethasone-17-valerate (once a day) and tretinoin (once a day) on the propeptide levels was also studied. Betamethasone alone caused a 60% decrease in the concentrations of PINP and PIIINP, and a similar decrease was found after the combination treatment, indicating that topical tretinoin administered during short treatment periods does not counteract the inhibitory effect of a potent corticoid on collagen propeptides.

Prednicarbate versus conventional topical glucocorticoids: pharmacodynamic characterization in vitro.

PURPOSE: Pharmacodynamic characterization of topical glucocorticoids as prednicarbate (PC), its metabolites prednisolone 17-ethylcarbonate (PEC) and prednisolone (PD), betamethasone 17-valerate (BMV), betamethasone (BM) and desoximetasone (DM) by evaluating their effects on epidermal and dermal cells. Synopsis of pharmacokinetic and pharmacodynamic studies, possibly explaining the improved benefit-risk ratio of prednicarbate. METHODS: Isolated foreskin keratinocytes were used to investigate the influence on epidermal inflammatory processes, dermal fibroblasts of the same origin to study antiproliferative activities of glucocorticoids. Interleukins were measured by ELISA-assay, the influence on II-1 alpha-production also on mRNA-level by RNAse protection assay. Proliferation was assessed by 3H thymidine incorporation and biodegradation by HPLC/UV-absorption. Cell viability was controlled by MTT assay. RESULTS: In keratinocytes, inflammation was induced by TNF alpha, resulting in an increased II-1 alpha synthesis. This cytokine was particularly suppressed by PC and BMV, whereas PEC, PD, DM and BM were less potent (p < or = 0.05). Since, however, the double ester PC is rapidly degraded in keratinocytes, a RNAse-protection assay of II-1 alpha mRNA was performed allowing short incubation times and thus minimizing biodegradation effects. In agreement with the previous experiment, the antiinflammatory potency of native PC was confirmed. In fibroblasts, II-1 alpha and II-6 synthesis indicate proliferation and inflammation respectively. Whereas PC inhibited II-1 alpha and II-6 production in fibroblasts to a minor extent only, it was strongly reduced by the conventional glucocorticoids and PEC (p < or = 0.05). The minor unwanted effect of PC on fibroblasts was also reflected by its low influence on cell proliferation as assayed by 3H thymidine incorporation. More pronounced antiproliferative features were observed with BM, PEC and especially BMV. CONCLUSIONS: Correlating antiphlogistic effects in keratinocytes (suppression of II-1 alpha) with antiproliferative effects in fibroblasts (suppression of II-1 alpha and II-6), the improved benefit-risk ratio of PC compared to conventional glucocorticoids does not result only from distinct drug metabolism in the skin but also from a specific influence on the cytokine network.

Recovery of human skin collagen synthesis after short-term topical corticosteroid treatment and comparison between young and old subjects.

In the present study, the recovery of the collagen synthesis rate after topical potent glucocorticoid treatment in the human skin in vivo was investigated. In the first experiment, two age groups were compared: young subjects with an age range of 21-26 years (mean 23), and old subjects, aged 55-70 years (mean 64). Twenty healthy male volunteers applied betamethasone-17-valerate to their abdominal skin for 3 days twice a day. Suction blisters were induced on the treated areas, and on the opposite side (healthy non-treated skin), of the abdominal skin on the day following the discontinuation of the treatment, and on the second and seventh day. In another experiment, suction blisters were induced after the treatment and 2 weeks later on the treated area and on healthy skin, in eight male volunteers. In both experiments, the aminoterminal propeptides of type I and III collagens (PINP and PIIINP, respectively) were measured radioimmunologically from the suction blister fluid. Corticosteroid treatment decreased the collagen synthesis in both age groups after a 3-day treatment period, and essentially no recovery in the collagen synthesis could be seen during a 1-week corticoid-free period. The inhibition and downregulation of collagen synthesis in the corticoid-treated skin was similar in both young and old subjects, up to 7 days after the treatment. During the 2-week corticoid-free period, collagen synthesis was recovered to about 50% of the level seen in the non-treated skin, indicating that collagen synthesis is not completely normalized in the human skin even during a 2-week corticoid-free period.

Ultrastructure of murine epidermis treated with the vitamin D3 analogue KH-1060.

A new highly potent analogue (KH-1060) of vitamin D3 has been recently shown to stimulate the growth and differentiation of keratinocytes. This study was intended to determine the effects of this new analogue on epidermis at the ultrastructural level. KH-1060 was applied topically on the backs of hairless mice for 4 weeks; the skin was then studied by routine electron microscopy. The effects were compared with those of betamethasone-17-valerate and with concomitant treatment of KH-1060 following betamethasone. KH-1060 stimulated normal function of keratinocytes and formed a thick epidermis. The ultrastructure of the thick epidermis represents an enhanced normal process of keratinization and proliferation. Moreover, KH-1060 diminished the atrophogenic effects of betamethasone.

Topical mometasone furoate and betamethasone-17-valerate decrease collagen synthesis to a similar extent in human skin in vivo.

Topical corticosteroids are used extensively to treat inflammatory skin diseases. Long-term use, however, may be associated with adverse effects such as skin atrophy. New steroids have been developed with the objective of increasing efficacy and reducing the incidence of adverse effects. Mometasone furoate (MMF) is one of these new derivatives. The aim of our study was to compare the effects of MMF and betamethasone-17-valerate (BM-17-valerate) on collagen synthesis in human skin in vivo. Fifteen healthy male volunteers applied MMF, BM-17-valerate and vehicle for 1 week to different areas of abdominal skin. Suction blisters were raised on these areas, and a control site, and procollagen propeptide (PICP, PINP, PIIINP) levels in the suction blister fluid were measured by radioimmunoassay. Skin thickness was measured ultrasonically by Dermascan A at the end of the treatment period. The levels of the three propeptides in suction blister fluid were reduced to similar extent by MMF and BM-17-valerate. The 1-week treatment period had no detectable influence on skin thickness. We conclude that MMF and BM-17-valerate decrease collagen synthesis to the same extent in human skin in vivo.

Induction of lipocortin 1 by topical steroid in rat skin.

Western blotting and densitometric analysis of extracts obtained from EDTA extraction of skin segments showed greater extracellular Lipocortin 1 (LC1) in skin sites from steroid-treated animals compared to that seen in matched vehicle treated animals. Extracellular LC1 was maximal 3 hr after steroid, less was found in skin after 6 hr and levels had returned to basal at 18 hr. Pre-treatment of rats with the glucocorticoid receptor antagonist RU38486 (20 mg/kg) prevented the steroid induction of extracellular LC1 at both the 3 and 6 hr time-points. Systemic treatment of rats with betamethasone sodium phosphate (0.1-1 mg/kg) showed that the induction of LC1 on the cell surface was both time- and dose-dependent. Oedema in rat skin caused by 5-hydroxytryptamine (5-HT), platelet activating factor (PAF) and zymosan activated serum (ZAS) was assessed using 125I-labelled human serum albumin. Following a 3 hr topical treatment with betamethasone-17-valerate the inflammatory activities of all of the tested stimuli were significantly attenuated demonstrating that at this time-point the topical steroid was biologically active. Topical steroid treatment of the skin resulted in a translocation of LC1 to the cell surface, which was maximal after a 3 hr period and was also temporally associated with the anti-inflammatory effect of these agents.