Treatment Of Inflammatory Skin Diseases Research Articles

Blocking MAPK Signaling Downregulates CCL21 in Lymphatic Endothelial Cells and Impairs Contact Hypersensitivity Responses

CCL21 expression by lymphatic endothelial cells (LECs) is essential for migration of CCR7+ immune cells from skin to regional lymph nodes (LNs). We investigated the importance of mitogen-activated protein kinase (MAPK) signaling in CCL21 expression by ECs in vitro and in vivo. Normal human dermal lymphatic microvascular ECs (HMVEC-dLy) stimulated in vitro with oncostatin M (OSM) expressed high amounts of CCL21 mRNA. CCL21 protein expression by HMVEC-dLy was also markedly increased by OSM compared with unstimulated cultures. Marked phosphorylation of MAPK 44/42 was detected in HMVEC-dLy stimulated by OSM. CCL21 expression by HMVEC-dLy was blocked by a JAK inhibitor 1, JAK3 inhibitor, and U0126 (a MAPK kinase inhibitor) in vitro, all of which blocked phosphorylation of MAPK 44/42. In addition, injection of U0126 into murine skin significantly decreased CCL21 mRNA and protein expression. Moreover, injection of U0126 before sensitization decreased migration of dendritic cells to draining LNs and decreased contact hypersensitivity responses. In summary, these results suggest that the MAPK pathway is important for CCL21 expression by LECs in vitro and in vivo. Blocking MAPK signaling within skin may offer a novel approach to treatment of inflammatory skin diseases.

Development and validation of a HPAE-PAD method for the quantification of CGP69669A, a sialyl Lewisx mimetic, in skin permeation studies

A simple, rapid, precise and specific isocratic HPAE-PAD method for quantification of CGP69669A was developed and validated. CGP69669A is a glycomimetic of sialyl Lewis(x) and an antagonist of E-selectin with potential application in the treatment of inflammatory skin disease. Quantification was performed using a Dionex CarboPac(TM) PA-200 anion-exchange column (3 × 250 mm) with 100 mm NaOH solution as mobile phase, a flow rate of 0.50 mL/min and an injection volume of 10 μL. A quadruple potential waveform was used to detect the carbohydrate (+0.1 V from 0.00 to 0.40 s, -2.0 V from 0.41 to 0.42 s, +0.6 V at 0.43 s and -0.1 V from 0.44 to 0.50 s with current integrated between 0.20 and 0.40 s for detection) and rafinose was employed as an internal standard. The optimized conditions enabled rapid elution of CGP69669A (at 3.0 min) without interference from solvent peaks or substances present in the skin. The method showed good intra- and inter-day precision and accuracy and the response was linear from 1.0 to 25 µg/mL. This is the first validated direct method for the quantification of CGP69669A. It will now be employed in studies investigating the topical and transdermal delivery of CGP69669A in vitro and in vivo and it should also be of use for other applications of this molecule.

Evaluation of Anti-inflammatory and Atrophogenic Effects of Glucocorticoids on Reconstructed Human Skin

Topical glucocorticoids (GCs) are extensively used in the treatment of inflammatory skin diseases. However, their long-term use is often accompanied by severe and eventually irreversible adverse effects, with atrophy being the most important limitation. Currently, most non-clinical studies involve animal testing, so the results are not always representative of the situation in humans. The aim of this project was to establish an in vitro test protocol for the evaluation of the anti-inflammatory and atrophic potential of topically applied GCs in reconstructed human skin. Initial studies with fibroblasts and keratinocytes confirmed the anti-inflammatory and atrophogenic effects of GCs, as evidenced by decreased cytokine production and collagen mRNA expression. In non-pretreated reconstructed human skin (EpiDermFT™), the topical application of GCs for seven days strongly reduced the secretion of interleukin (IL)-6. GC-induced skin atrophy, known to appear only after prolonged treatment, was not detected by the analysis of epidermal thickness and collagen mRNA expression. However, reproducible epidermal inflammation was established for the first time in reconstructed human skin. Topical treatment with tumour necrosis factor (TNF) increased IL-6 release and strongly reduced epidermal thickness accompanied by severe parakeratosis. GC treatment of reconstructed human skin reduced IL-6 levels and completely resolved parakeratosis, leading to the normalisation of epidermal thickness. These induced inflammatory conditions mimic more closely the clinical situations in which GCs are used, and therefore appear to be more suitable for future investigations for the establishment of a human-based in vitro test protocol for evaluating wanted and unwanted GC effects.

Peoniflorin suppresses tumor necrosis factor-α induced chemokine production in human dermal microvascular endothelial cells by blocking nuclear factor-κB and ERK pathway

Peoniflorin (PF) extracted from the root of Paeonia lactiflora pall displays anti-inflammation and antioxidant properties in several animal models. Chemokines are vital for directing the movement of circulating leukocytes to the sites of inflammation and are involved in the pathogenesis of various inflammatory skin diseases. Herein, we investigated the effects and potential mechanisms of PF on tumor necrosis factor-α (TNF-α) induced chemokine production in human dermal microvascular endothelial cells. Human dermal microvascular endothelial cell line (HMEC-1) was treated by TNF-α with or without PF. PF markedly attenuated TNF-α-induced chemokines (including CCL2, CCL5, CCL20, CXCL8, CXCL16 and CX3CL1) mRNA expression in HMEC-1. PF also reduced the secretion of these chemokines in culture supernatants. In addition, endothelial activation in the presence of PF markedly blocked the chemotactic activities of TNF-α-stimulated HMEC-1 supernatant on promyelocytic leukemia cell line (HL-60) or the acute mature monocytic leukemia cell line (THP-1) cell migration. Furthermore, Western blot data revealed TNF-α upregulated phosphorylation of inhibitor of κB-α (IκBα) and phosphorylation of extracellular signal-regulated kinase (ERK)1/2, which was almost completely reversed by PF. Finally, PF inhibited nuclear factor-κB (NF-κB) nuclear translocation to the nucleus. Taken together, our data provide the first evidence that PF has an anti-inflammatory ability against TNF-α-induced chemokine production and leukocyte migration, which may be at least partly related to the inhibition of NF-κB and ERK pathway. PF may be a candidate medicine for the treatment of inflammatory skin diseases.

Pituitary Adenylate Cyclase Activating Polypeptide: An Important Vascular Regulator in Human Skin in Vivo

Pituitary adenylate cyclase-activating peptide (PACAP) is an important neuropeptide and immunomodulator in various tissues. Although this peptide and its receptors (ie, VPAC1R, VPAC2R, and PAC1R) are expressed in human skin, their biological roles are unknown. Therefore, we tested whether PACAP regulates vascular responses in human skin in vivo. When injected intravenously, PACAP induced a significant, concentration-dependent vascular response (ie, flush, erythema, edema) and mediated a significant and concentration-dependent increase in intrarectal body temperature that peaked at 2.7°C. Topical application of PACAP induced marked concentration-dependent edema. Immunohistochemistry revealed a close association of PACAP-immunoreactive nerve fibers with mast cells and dermal blood vessels. VPAC1R was expressed by dermal endothelial cells, CD4+ and CD8+ T cells, mast cells, and keratinocytes, whereas VPAC2R was expressed only in keratinocytes. VPAC1R protein and mRNA were also detected in human dermal microvascular endothelial cells. The PACAP-induced change in cAMP production in these cells demonstrated VPAC1R to be functional. PACAP treatment of organ-cultured human skin strongly increased the number of CD31+ vessel cross-sections. Taken together, these results suggest that PACAP directly induces vascular responses that may be associated with neurogenic inflammation, indicating for the first time that PACAP may be a crucial vascular regulator in human skin in vivo. Antagonists to PACAP function may be beneficial for the treatment of inflammatory skin diseases with a neurogenic component.

Clinical Evaluation of Prednisolone 17-Valerate 21-Acetate (Lidomex Kowa®Lotion) in the Treatment of Inflammatory Skin Diseases

Clinical Evaluation of Prednisolone 17-Valerate 21-Acetate (Lidomex Kowa®Lotion) in the Treatment of Inflammatory Skin Diseases

Zebrafish bioassay-guided microfractionation combined with CapNMR a comprehensive approach for the identification of anti-inflammatory and anti-angiogenic constituents of Rhynchosia viscosa

Zebrafish have recently emerged as an attractive in vivo system for functional genomics and drug discovery [1]. Because of their small size, rapid development, optical transparency, and high genetic, physiologic, and pharmacologic similarity with humans, zebrafish embryos and larvae are also an ideal model for natural product discovery. As zebrafish bioassays require only microgram amounts of crude extracts, chromatographic fractions, and pure compounds, we are developing a zebrafish-based natural product discovery platform that takes advantage of modern techniques for the isolation and structural elucidation of natural products, such as UHPLC-TOF-MS profiling, LC-MS microfractionation and subsequent capillary NMR characterization [2]. An in vivo, zebrafish-based anti-inflammatory screen of methanolic extracts of East African medicinal plants resulted in the identification of R. viscosa, which revealed potent inhibition of leukocyte migration after larval tail transection in the presence of bacterial lipopolysaccharides. This extract also displayed anti-angiogenic activity in transgenic zebrafish with vasculature-specific expression of GFP. Intriguingly, R. viscosa is used by traditional healers in Tanzania for the treatment of inflammatory skin disorders and insect bites, corroborating our findings in zebrafish. Microfractionation of the crude methanolic extract was performed, and individual fractions tested for bioactivity in zebrafish. One highly active fraction was subjected to HR-ESI-MS and CapNMR analysis, resulting in the identification of genistein – a known inhibitor of inflammation and angiogenesis. These results indicate the potential of zebrafish bioassay-guided microfractionation, in combination with sub-milligram NMR techniques, to rapidly identify bioactive natural products.

Pimecrolimus Induces Apoptosis of Mast Cells in a Murine Model of Cutaneous Mastocytosis

Background: Cutaneous mastocytosis (CM) is a common type of mastocytosis. Current treatment of CM is generally symptomatic. Pimecrolimus has been demonstrated as an effective anti-inflammatory drug for the treatment of inflammatory skin diseases, but whether it treats CM remains unknown. Methods: The murine model of CM was induced by subcutaneous injection of 100 µg/kg recombinant murine stem cell factor (rmSCF) for a total of 17 days in Balb/c mice. Beginning on the 8th day, treatment with pimecrolimus 1% cream or vehicle was performed topically and daily for 10 days. The clinical signs of CM were scored, and pathological analysis was performed with toluidine blue staining and hematoxylin and eosin staining. The in situ apoptotic mast cells (MCs) were studied by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. The cutaneous histamine level was measured by ELISA. Results: In the rmSCF-treated mice, the clinical signs of CM, including erythema, wheal after rubbing lesion skins, and increased thickness of skin, were obvious compared to control mice, and were reduced after pimecrolimus treatment. The numbers of cutaneous MCs and neutrophils were significantly greater in mice with CM than in control mice, and pimecrolimus treatment decreased the numbers of MCs but not neutrophils. Extensive apoptosis of cutaneous MCs was observed in pimecrolimus-treated mice. The cutaneous histamine level was elevated in the mice with CM compared with healthy controls, and was lowered after treatment with pimecrolimus. Conclusions: Pimecrolimus effectively treats CM by reducing the density of cutaneous MCs and the subsequent histamine production through inducing MCs apoptosis.

IKKβ Leads to an Inflammatory Skin Disease Resembling Interface Dermatitis

IKKbeta is a subunit of the IkappaB kinase (IKK) complex required for NF-kappaB activation in response to pro-inflammatory signals. NF-kappaB regulates the expression of many genes involved in inflammation, immunity, and apoptosis, and also controls cell proliferation and differentiation in different tissues; however, its function in skin physiopathology remains controversial. In this study we report the alterations caused by increased IKKbeta activity in skin basal cells of transgenic mice. These animals suffered chronic inflammation with abundant macrophages and other CD45(+) infiltrating cells in the skin, which resulted in epidermal basal cell injury and degeneration of hair follicles. They showed histological features characteristic of interface dermatitis (ID). This phenotype is accompanied by an increased production of inflammatory cytokines by transgenic keratinocytes. Accordingly, transcriptome studies show upregulation of genes associated with inflammatory responses. The inflammatory phenotype observed as a consequence of IKKbeta overexpression is independent of T and B lymphocytes, as it also arises in mice lacking these cell types. In summary, our data indicate the importance of IKKbeta in the development of ID and in the homeostasis of stratified epithelia. Our results also support the idea that IKKbeta might be a valid therapeutic target for the treatment of skin inflammatory diseases.

Narrow-band ultraviolet B as a potential alternative treatment for resistant psychogenic excoriation: an open-label study

Narrow-band ultraviolet therapy has been used successfully for the treatment of inflammatory skin disorders and generalized pruritus. We have prospectively evaluated seven consecutive patients with resistant psychogenic excoriation (PE) treated with narrow-band ultraviolet B (NB-UVB). Approximately 70% of all patients showed improvement in their condition. NB-UVB therapy was well tolerated, with no serious side effects. We may conclude that, when treating a patient with PE, NB-UVB in combination with other approaches may provide extra benefit in resistant cases.

Botanicals in Dermatology

Botanical extracts and single compounds are increasingly used in cosmetics but also in over-the-counter drugs and food supplements. The focus of the present review is on controlled clinical trials with botanicals in the treatment of acne, inflammatory skin diseases, skin infections, UV-induced skin damage, skin cancer, alopecia, vitiligo, and wounds. Studies with botanical cosmetics and drugs are discussed, as well as studies with botanical food supplements. Experimental research on botanicals was considered to a limited extent when it seemed promising for clinical use in the near future. In acne therapy, Mahonia, tea tree oil, and Saccharomyces may have the potential to become standard treatments. Mahonia, Hypericum, Glycyrrhiza and some traditional Chinese medicines appear promising for atopic dermatitis. Some plant-derived substances like dithranol and methoxsalen (8-methoxypsoralen) [in combination with UVA] are already accepted as standard treatments in psoriasis; Mahonia and Capsicum (capsaicin) are the next candidates suggested by present evidence. Oral administration and topical application of antioxidant plant extracts (green and black tea, carotenoids, coffee, and many flavonoids from fruits and vegetables) can protect skin from UV-induced erythema, early aging, and irradiation-induced cancer. Hair loss and vitiligo are also traditional fields of application for botanicals. According to the number and quality of clinical trials with botanicals, the best evidence exists for the treatment of inflammatory skin diseases, i.e. atopic dermatitis and psoriasis. However, many more controlled clinical studies are needed to determine the efficacy and risks of plant-derived products in dermatology. Safety aspects, especially related to sensitization and photodermatitis, have to be taken into account. Therefore, clinicians should not only be informed of the beneficial effects but also the specific adverse effects of botanicals used for dermatologic disorders and cosmetic purposes.

Thalidomide Inhibits Activation of Caspase-1

Thalidomide is an efficient anti-inflammatory and anti-angiogenic drug, but its therapeutic use is problematic due to a strong teratogenic activity. Nevertheless, thalidomide was approved for the treatment of inflammatory skin diseases and certain types of cancer, and it is extensively tested for several other indications. Recently, we demonstrated that active caspase-1, whose activation is dependent on inflammasome complexes, is required for unconventional protein secretion of proinflammatory cytokines such as IL-1 and of the proangiogenic fibroblast growth factor 2. In this study, we show that pharmacological doses of thalidomide strongly reduced the secretion of both proteins. Thalidomide-treated cells also released less of other leaderless proteins, which require caspase-1 activity for their secretion. In line with these findings, the drug inhibited activation and activity of caspase-1 in cultured cells but not in vitro. The latter finding suggests that the pharmacological activity is exerted by a metabolite of the drug. The anti-inflammatory activity of thalidomide was also mediated via caspase-1 in mice. These findings represent a novel mechanism by which thalidomide exerts its pharmacological activity and suggest that inhibition of the activity of IL-1 might represent a novel strategy to substitute thalidomide.

Characterization of ZK 245186, a novel, selective glucocorticoid receptor agonist for the topical treatment of inflammatory skin diseases

Glucocorticoids are highly effective in the therapy of inflammatory diseases. Their value, however, is limited by side effects. The discovery of the molecular mechanisms of the glucocorticoid receptor and the recognition that activation and repression of gene expression could be addressed separately opened the possibility of achieving improved safety profiles by the identification of ligands that predominantly induce repression. Here we report on ZK 245186, a novel, non-steroidal, low-molecular-weight, glucocorticoid receptor-selective agonist for the topical treatment of inflammatory dermatoses. Pharmacological properties of ZK 245186 and reference compounds were studied in terms of their potential anti-inflammatory and side effects in functional bioassays in vitro and in rodent models in vivo. Anti-inflammatory activity of ZK 245186 was demonstrated in in vitro assays for inhibition of cytokine secretion and T cell proliferation. In vivo, using irritant contact dermatitis and T cell-mediated contact allergy models in mice and rats, ZK 245186 showed anti-inflammatory efficacy after topical application similar to the classical glucocorticoids, mometasone furoate and methylprednisolone aceponate. ZK 245186, however, exhibits a better safety profile with regard to growth inhibition and induction of skin atrophy after long-term topical application, thymocyte apoptosis, hyperglycaemia and hepatic tyrosine aminotransferase activity. ZK 245186 is a potent anti-inflammatory compound with a lower potential for side effects, compared with classical glucocorticoids. It represents a promising drug candidate and is currently in clinical trials.

Reduced Oxazolone-Induced Skin Inflammation in MAPKAP Kinase 2 Knockout Mice

Mitogen-activated protein kinase (MAPK) AP kinase 2 (MK2) is a serine/threonine kinase that is phosphorylated and activated by p38 MAPK. MK2 regulates the expression of various proinflammatory cytokines including TNF-alpha, IL-1beta, IL-6, and IL-8. Recently, MK2 was demonstrated to be activated in lesional psoriatic epidermis. This study investigates for the first time the role of MK2 in skin inflammation using the model of oxazolone-induced acute allergic contact dermatitis in mice. We show that oxazolone treatment leads to increased expression and sustained activation of both p38 MAPK and MK2. The inflammatory response was determined by ear thickness, myeloperoxidase activity, and histology after oxazolone challenge. Pretreatment with the p38 MAPK inhibitor SB202190 and genetic ablation of MK2 inhibit this inflammatory response. In particular, IL-1beta and, to a smaller but significant extent, also TNF-alpha and IFN-gamma expression were decreased in MK2 knockout mice compared with wild-type mice. These results indicate that MK2 is a potential target for the treatment of inflammatory skin diseases.

Effect of Pinus massoniana bark extract on IFN-γ-induced ICAM-1 expression in HaCaT human keratinocytes

Aims of the study Pinus massoniana bark extract (PMBE) with known anti-oxidant activity is comprised of various flavonoids including several bioactive compounds. We found that PMBE contains 1.27% taxifolin, a well-studied compound with known anti-inflammatory activity. Therefore, in the present study, we evaluated the effects of PMBE and taxifolin on intercellular adhesion molecule-1 (ICAM-1) expression. Materials and Methods PMBE and taxifolin were prepared. After HaCaT cells were pre-treatmented with PMBE and taxifolin, HaCaT cells were treatmented with 1000 U/ml IFN-γ for 24 h. Results Treatment of HaCaT cells with 1000 U/ml IFN-γ for 24 h markedly increased ICAM-1 expression. However, PMBE pre-treatment (40 μg/ml for 24 h) significantly inhibited IFN-γ-induced ICAM-1 expression. In equal concentrations of taxifolin, PMBE-mediated inhibition of ICAM-1 mRNA and protein expression was greater than taxifolin mediated-inhibition, and the front on inhibition of ICAM-1 protein expression was 2.24–2.30-fold of the latter. When cells were treated with both compounds at a concentration of 40 μg/ml, PMBE-mediated inhibition of ICAM-1 mRNA was also greater than taxifolin-mediated inhibition and PMBE on inhibition of ICAM-1 protein expression was 2.60–3.00-fold the inhibition mediated by taxifolin. Conclusions PMBE including additional bioactive compounds may possibly synergize to inhibit transcription and translation of inducible ICAM-1expression and PMBE was greater than monomeric flavonoid taxifolin. These results indicate that PMBE exhibits great potential as a therapeutic treatment for inflammatory skin diseases.

Reactive Oxygen Species in Tumor Necrosis Factor-α-Activated Primary Human Keratinocytes: Implications for Psoriasis and Inflammatory Skin Disease

The multifunctional cytokine tumor necrosis factor-alpha (TNF-alpha) is known to play an important role in inflammatory and immunological responses in human skin. Although it has been documented that reactive oxygen species (ROS) are involved in TNF-alpha-induced signaling pathways associated with certain inflammatory diseases, their role in TNF-alpha signaling cascades has not been examined in primary human keratinocytes used as a model of inflammatory skin disease and psoriasis. Employing a series of in vitro and in cellulo approaches, we have demonstrated that in primary human keratinocytes (i) TNF-alpha rapidly induces ROS generation, IkappaB degradation, NF-kappaB p65 nuclear translocation, and ultimately production of inflammatory cytokines; (ii) TNF-alpha-induced cytokine production is mediated both by the mammalian target of rapamycin signaling pathway via NF-kappaB activation and by ROS; (iii) TNF-alpha-dependent NF-kappaB activation (that is, IkappaB degradation and NF-kappaB p65 nuclear translocation) is not mediated by ROS; and (iv) a cell-penetrating derivative of the antioxidant enzyme, catalase, as well as taurine and N-acetyl-cysteine attenuate the TNF-alpha-induced production of cytokines. These latter results suggest that catalase and perhaps other antioxidants should be considered as part of a more specific and effective therapy for the treatment of inflammatory skin diseases, including psoriasis.

Inhibition of atopic dermatitis‐like skin lesions by topical application of a novel ceramide derivative, K6PC‐9p, in NC/Nga mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease that commonly begins in childhood. K6PC-9p (N-(Ethyl dihydrogenphosphate)-2-hexyl-3-oxo-decanamide) is a synthetic ceramide derivative of PC-9S (N-Ethanol-2-mirystyl-3-oxo-staramide), which was known to be effective in atopic patients. In this study, we examined the effect of topical application of K6PC-9p on skin inflammation and AD-like skin lesions in mouse models. K6PC-9p dose-dependently inhibited phorbol ester-induced increase in ear thickness in BALB/c mice. Moreover, topical application of K6PC-9p suppressed dust mite extract-induced AD-like skin lesions in NC/Nga mice. Histopathological analysis revealed that both ear swelling and leucocyte infiltration were suppressed by K6PC-9p treatment. K6PC-9p also suppressed IL-4 and TNF-alpha expression in the ears and mast cell infiltration into the ears in NC/Nga mice. Further study demonstrated that K6PC-9p inhibited ConA-induced IL-4 secretion and LPS-induced macrophage activation. Taken together, our results showed that topical application of K6PC-9p exerts beneficial effects in animal model of skin inflammation and AD, suggesting that K6PC-9p might be a promising topical agent for the treatment of inflammatory skin diseases.

Anti‐inflammatory potential of a lipolotion containing coriander oil in the ultraviolet erythema test

Coriander oil is used as an antimicrobial agent and as a natural fragrance. The present study investigated the anti-inflammatory potency of coriander oil in the ultraviolet (UV) erythema test in vivo. 40 volunteers were enrolled in this monocentric,randomized,placebo-controlled double-blind study.Test areas on the back were irradiated with the 1.5 fold minimal erythema dose UV-B. Subsequently, the test areas were treated under occlusion for 47 hours with a lipolotion containing 0.5% or 1.0% essential coriander oil. Hydrocortisone (1.0%) and betamethasone valerate (0.1%) in the vehicle served as positive controls.The vehicle was used as place-bo.The effect of the test substances on the UV-induced erythema was measured photometrically after 48 hours.Additionally,the skin tolerance of the test preparations was assessed on non-irradiated skin. Compared to placebo, the lipolotion with 0.5% coriander oil significantly reduced the UV-induced erythema, but it was not as effective as hydrocortisone. The skin tolerance of both coriander oil concentrations was excellent. The lipolotion containing coriander oil displayed a mild antiinflammatory effect in this study. It could be useful in the concomitant treatment of inflammatory skin diseases.

Treatment with pimecrolimus cream 1% clears irritant dermatitis of the periocular region, face and neck

Irritant dermatitis of the face and neck is particularly prevalent in women > or = 30 years old, who typically present with periocular cutaneous symptoms. Current therapies are limited, indicating a need for rapid, effective alternatives. Pimecrolimus cream 1%, a nonsteroid, cell-selective inhibitor of inflammatory-cytokine release, is effective in the treatment of inflammatory skin diseases, such as chronic irritant dermatitis of the hands, and thus offers a potential therapeutic option for this indication. This study reports on the safety and efficacy of pimecrolimus treatment in patients with irritant periocular dermatitis, extending to the face and neck in some patients. Twenty-seven patients with periocular irritant dermatitis (extending onto the face and neck in eight) were treated twice daily with pimecrolimus cream 1% for 7 d, followed by once-daily application for a further 7 d. Erythema, swelling, and pruritus were assessed at baseline, weeks 1-4 using a 4-point clinical score (0, absent; 1, mild; 2, moderate; and 3, severe). All patients showed marked improvement within 2-3 d of treatment with disease clearance in 23 of 27 patients within 14 d. In the remaining four patients, mild relapse occurred at weeks 3-4, but improvement was observed following a further 10-d treatment. Side-effects were mild and transient. Pimecrolimus cream 1% provides a new potential option for treatment of irritant dermatitis of the periocular region, head and neck. Further double-blind, controlled studies are required to confirm the efficacy and safety of pimecrolimus cream 1% for this indication.

1-Methylnicotinamide and nicotinamide: two related anti-inflammatory agents that differentially affect the functions of activated macrophages

Introduction:1-Methylnicotinamide (MNA), a major metabolite of nicotinamide (NA), is known to exert anti-inflammatory effects in vivo. Treatment of inflammatory skin diseases by topical application of MNA provides certain advantages over the use of NA. However, in contrast to NA, the molecular mechanisms of the anti-inflammatory properties of MNA are not well known. In this study the influence of exogenous MNA and NA in vivo on the generation of inflammatory mediators by macrophages (Mϕ) was investigated.Materials and Methods:Peritoneal Mϕ of CBA/J mice were activated in vitro with lipopolysaccharide and incubated with MNA or NA. The effect of these compounds on biological functions of Mϕ was measured by evaluation of the production of reactive oxygen species (ROS) by luminol-dependent chemiluminescence, cytokines and prostaglandin E2 (PGE2) by ELISA, and nitric oxide (NO) by the Griess method. Moreover, the expressions of inducible NO synthase and cyclooxygenase-2 were measured by Western blotting.Results:It was shown that at non-cytotoxic concentrations, NA inhibits the production of a variety of pro-inflammatory agents, such as tumor necrosis factor α, interleukin 6, NO, PGE2, and the generation of ROS. In contrast to NA, exogenous MNA inhibited only the generation of ROS, while its effect on the synthesis of other mediators was negligible.Conclusions:These results indicate that the anti-inflammatory properties of MNA demonstrated previously in vivo do not depend on its capacity to suppress the functions of immune cells, but more likely may be related to its action on vascular endothelium. The authors suggest that the limited permeability for exogenous MNA, in contrast to that for NA, may be responsible for its lack of suppressor activity against Mϕ.