New approaches to topical therapy

Chrysin Inhibits TNFα-Induced TSLP Expression through Downregulation of EGR1 Expression in Keratinocytes

Thymic stromal lymphopoietin (TSLP) is an epithelial cell-derived cytokine that acts as a critical mediator in the pathogenesis of atopic dermatitis (AD). Various therapeutic agents that prevent TSLP function can efficiently relieve the clinical symptoms of AD. However, the downregulation of TSLP expression by therapeutic agents remains poorly understood. In this study, we investigated the mode of action of chrysin in TSLP suppression in an AD-like inflammatory environment. We observed that the transcription factor early growth response (EGR1) contributed to the tumor necrosis factor alpha (TNFα)-induced transcription of TSLP. Chrysin attenuated TNFα-induced TSLP expression by downregulating EGR1 expression in HaCaT keratinocytes. We also showed that the oral administration of chrysin improved AD-like skin lesions in the ear and neck of BALB/c mice challenged with 2,4-dinitrochlorobenzene. We also showed that chrysin suppressed the expression of EGR1 and TSLP by inhibiting the extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK) 1/2 mitogen-activated protein kinase pathways. Collectively, the findings of this study suggest that chrysin improves AD-like skin lesions, at least in part, through the downregulation of the ERK1/2 or JNK1/2-EGR1-TSLP signaling axis in keratinocytes.

Anti-Inflammatory Effects of Alnus Sibirica Extract on In Vitro and In Vivo Models

Alnus sibirica extracts (ASex) have long been used in Oriental medicine to treat various conditions. To provide a scientific basis for this application and the underlying mechanism, we investigated the anti-inflammatory effects of ASex in vitro and in vivo. The in vitro model was established using human dermal fibroblasts (HDFs) treated with inflammatory stimulants (lipopolysaccharide, tumor necrosis factor-alpha, interferon-gamma). Lactate dehydrogenase and reverse transcription-polymerase chain reaction showed that ASex inhibited the increased expression of acute-phase inflammatory cytokines. The in vivo model was established by inducing skin inflammation in NC/Nga mice via the repeated application of house dust mite (HDM) ointment to the ears and back of the mice for eight weeks. HDM application increased the severity of skin lesions, eosinophil/mast cell infiltration, and serum immunoglobulin E levels, which were all significantly decreased by ASex treatment, demonstrating the same degree of protection as hydrocortisone. Overall, ASex showed excellent anti-inflammatory effects both in vitro and in vivo, suggesting its potential as an excellent candidate drug to reduce skin inflammation.

[Atopic dermatitis and tacrolimus in adults]

Topical treatment with tacrolimus is more effective than the placebo and the low potency corticosteroids in the treatment of atopic dermatitis (AD) in both adults and children while it has a similar potency as some topical corticosteroids of medium potency. Since it was put on the market, more evidence has been accumulating to make our previous statements and it has been demonstrated to have greater effectivity than topical pimecrolimus and oral cyclosporine. It is a safe drug and its side effects are of little importance. Specifically no side effects have been demonstrated due to its systemic absorption nor has there been any increase in skin infections. The most frequent side effect is burning sensation or increased pruritus in the area where the product is applied. It is more frequent if the lesions treated are very acute and is generally transitory, not causing the treatment to be discontinued. Furthermore, with the current information, it cannot be associated to an increase of any type of neoplasms.

Predicting long-term outcome in group treatment of atopic dermatitis

BACKGROUND

Psychological group treatments are effective adjuncts to dermatological treatments in improving dermatological symptoms and quality of life. However, no data are available on variables that may predict which patients benefit from such group treatments.

METHODS

On the basis of data from the Marburg group treatment study, we explored which variables are associated with successful treatment. Treatment outcome was defined by a marked reduction of dermatological symptoms at 1-year follow-up.

RESULTS

Regardless of the treatment condition, a high pretreatment level of scratching, a low serum IgE level, low scores on the internal Health Locus of Control Scale and a high frequency of coping-related cognitions regarding itching predicted good outcome at 1 year. Logistic regression analyses indicated that the predictive power of locus of control and itch-related cognitions differed between different treatment conditions.

CONCLUSION

In patients with atopic dermatitis, indication for psychological treatment may be based on the assessment of psychological target problems including excessive scratching and dysfunctional cognitions.

The Use of Topical Tacrolimus (FK506/Protopic) in Cutaneous Manifestations of Autoimmune Diseases

The cutaneous manifestations of autoimmune diseases, including systemic lupus erythematosus, are common and often recalcitrant to treatment. Unfortunately, therapy for lupus and other autoimmune skin diseases has not advanced and relies heavily on the use of oral and topical corticosteroids. Frequently, treatments prove less than ideal, either from toxicity or lack of efficacy. A topical form of the immunomodulating transplant medication, tacrolimus (FK-506, Protopic), has recently been developed and approved for use in treating atopic dermatitis. Its mechanism of action and local route of administration render tacrolimus a potentially attractive novel therapeutic alternative for the treatment of various autoimmune dermatologic conditions. We report our successful experience using this drug in 3 patients with autoimmune dermatologic disease who were referred to a tertiary care subspecialty clinic.

[New horizons in the treatment of atopic dermatitis]

Nearly fifty years after their introduction, corticoids continue to be one of the main pillars of dermatological therapy in general and in atopic dermatitis in particular. However, their use is limited by local and systemic adverse effects.There is enormous demand for anti-inflammatory agents not belonging to the corticoid group that would be useful in the different inflammatory dermatoses.In the last few years the therapeutic arsenal for atopic dermatitis has increased with two distinct groups of drugs: topical immunomodulators and leukotriene inhibitors. Both groups of drugs are new and new compounds belonging to these types of drugs will probably appear in the next few years.Among the alternatives to corticoids are the immunomodulators and the most promising of these are macrolide antibiotics. Tacrolimus (FK 506) and pimecrolimus (ASM 981) belong to this group of substances with a high capacity to inhibit T lymphocyte activation. Although they also act on other cells playing a role in atopic dermatitis (mastocytes, Langerhans' cells, B lymphocytes) their action on T lymphocytes seems to be the most important. In T lymphocytes, these drugs act by inhibiting the action of calmodulin, a vital enzyme in the activation chain of these cells that ends in the production of interleukin 2 and other proinflammatory cytokines.The accumulated evidence of the various publications seems to indicate that tacrolimus is a safe and effective treatment of atopic dermatitis in patients aged 2 years or more. The drug was approved for clinical use 3 years ago in Japan and more than 1 year ago in the United States. The number of randomized clinical trials comparing this drug with placebo or various corticoids demonstrate that its action is overwhelming. Its anti-inflammatory action is similar to that of high-potency topical corticoids. Two doses daily are required and the drug has been tested in patients with moderate-to-severe atopic dermatitis. Published data from more than 10,000 patients guarantee its safety. The most frequent short-term adverse effect is a burning sensation in the site of application lasting a few minutes.Pimecrolimus has not yet been commercialized in any country and is currently undergoing phase III clinical investigations. It has been tested in three clinical trials in patients aged more than 3 months old with mild-moderate atopic dermatitis. Its safety profile is good and similar to that of tacrolimus.The number and quality of the data provided by studies of treatment with leukotriene inhibitors (zafirlukast, montelukast and zileuton) is much lower but these substances seem to warrant further investigation. Only five small series undergoing treatment with these products have been published.

Irritant contact dermatitis: is there an immunologic component?

Irritant contact dermatitis (ICD) describes a multifactorial disease resulting from exposure to occupational irritants. Though often characterized as a localized reaction, there are at least 10 forms of ICD, several of which possess systemic involvement. The exact mode of irritant action in ICD is not completely understood, but recent literature suggests that an immunologic-like component may be present. The correlation between the morphology, clinical manifestations and chemokines involved in allergic contact dermatitis and irritant contact dermatitis will be discussed and studies indicating an irritant "immunologic-like" response will be reviewed and analyzed.