Antipsoriatic Drug Research Articles

Fluorescence remission spectroscopy of psoriatic lesions and the effect of topical anthralin therapy

Psoriatic lesions are characterized by induration, scaling and erythema. Erythema is a result of inflammation and increased microvascular blood flow. Anthralin is the strongest topical antipsoriatic drug that causes clearing of psoriatic lesions and temporary remission. The objective evaluation of skin perfusion might be a suitable way to gain a better insight in the pathophysiological process of this disease and to evaluate the response to antipsoriatic anthralin therapy. We evaluated 21 psoriatic lesions (plaques, patches and pinpoint lesions) including 4 lesions in remission with anthralin induced erythema and 4 controls of healthy, uninvolved skin. We performed the measurements with a combined fluorescence and remission imaging (FRIS). The FRIS sensor is coupled with a touch screen industrial computer. The equipment consists of a white-light halogen lamp (20 W), two VIS-spectrometer modules (Zeiss) for remission detection and references. Imaging is realized by CCD-colour camera module and white light ring-lighting. Fluorescence emission was realized using an ultraviolet LED with a wavelength of 370 nm. The fluorescence detector is a highly sensitive MCS CCD (Zeiss) with an integration time of 2.5 sec. Spectral remission of psoriatic skin is characterized by a pronounced decrease (60-80%) of the haemoglobin double-peak compared to uninvolved skin. The NADH-fluorescence is diminished in lesional psoriatic skin including anthralin-treated areas with clinical remission. Vascular perfusion is increased in psoriatic lesions as demonstrated by remission spectroscopy. NADH-fluorescence is reduced in lesional psoriatic skin and in anthralin-induced erythema. FRIS is a suitable tool for objective evaluation of the cutaneous response to antipsoriatic treatment.

Syntheses and evaluation of the antioxidant activity of acitretin analogs with amide bond(s) in the polyene spacer

Ester analogs of the antipsoriatic drug acitretin were synthesized by coupling either anilines with N-protected indole-3-carboxylic acid, followed by deprotection and coupling with O-monoprotected dicarboxylic acids or Wittig reaction of indole-3-carboxaldehyde, 3-acetyl-1-tosylpyrrole and 4-amino-9-fluorenone with Ph3P=CHCO2tBu, followed by N-deprotection, where necessary, and finally coupling with cinnamoyl fluorides. Corresponding free acids were obtained through TFA-mediated carboxyl group deprotection. Although these analogs and acitretin showed very low reducing abilities, analogs 5, 6, 8 and 12 strongly inhibited LOX with IC50 values ranging from 35-65 microM. Acitretin and its analogs 5-7, 10, 11 and 15 inhibited lipid peroxidation more strongly than trolox whereas acitretin and analog 4 were in vivo more potent anti-inflammatory agents on rat paw oedema induced by Carrageenan than indomethacin.

Decreased EGFR mRNA expression in response to antipsoriatic drug dithranol in vitro

Dithranol is enormously effective in the treatment of psoriasis; however its molecular mode of action should be further elucidated. Since epidermal growth factor receptor (EGFR) is involved in the pathogenesis of psoriasis, the objective of this study was to investigate the transcriptional effect of dithranol on EGFR gene expression in the HaCaT keratinocyte cell line, which is commonly employed as a model system to study psoriasis including experiments examining the effects of therapeutic drugs and cellular regulators on keratinocytes. Cultured HaCaT cells were treated with 0.1-0.5 ig/ml dithranol for 30 min. After 4 h, total cellular RNA isolated from HaCaT cells was reverse transcribed to cDNA which was subjected to polymerase chain reaction (PCR) with specific primer pair for EGFR. We found that dithranol treatment down-regulated the EGFR mRNA of HaCaT cells in a concentration-dependent manner. Our result was further substantiated using a quantitative real-time PCR approach. Taken together, the dithranol-induced down-regulation of the EGFR in cultured human keratinocytes might help to disclose the molecular therapeutic action of the drug.

10th Annual Congress of the German Association of Clinical Pharmacology

10th Annual Congress of the German Association of Clinical Pharmacology

Infliximab in the treatment of plaque type psoriasis

Psoriasis is a chronic and immunomediated skin disease characterized by erythematous scaly plaques. Psoriasis affects approximately 1% to 3% of the Caucasian population. Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine that plays a critical role in the pathogenesis of psoriasis. Infliximab is an anti-TNF-α drug widely used for the treatment of plaque type psoriasis and psoriatic arthritis. Controlled clinical trials demonstrated that infliximab is characterized by a high degree of clinical response in moderate to severe plaque psoriasis. Moreover infliximab showed rapid efficacy in nail psoriasis which represents a therapeutic challenge for dermatologists and a relevant source of distress for patients with plaque psoriasis. This anti-TNF-α has an encouraging safety profile, especially as long as physicians are watchful in prevention and early diagnosis of infections and infuse reactions. The efficacy, tolerability and safety profiles suggest infliximab as a suitable anti-psoriatic drug in the long-term treatment of a chronic disease such as plaque-type psoriasis.

건선(psoriasis)에서 혈관내피 성장인자(VEGF)에 대한 acitretin의 효과

건선(psoriasis)은 각화(keratinization)의 장애에 의한 질병으로 잘 알려져 있다. 이 질병에있어서, 몇몇 보고에 따르면 피부 미세혈관이 증가되고, 혈관 신생 유도 인자들인 내피 성장 인자(VEGF) 및 섬유아세포 성장 인자(bFGF)가 과발현된다고 보고 되어져 있다. 신생혈관(angiogenesis)은 건선의 진행성에 있어 중요한 역할을 할지도 모른다. Acitretin은 keratinocyte 성장과 분화에 그것의 잠재적인 활동 때문에 anti-psoriatic 약으로 널리 이용된다. 그러나 신생혈관에 대한 효과는 여전히 불명확하다. 본 면역혈청학적 연구 목표는 건선염 피부에 있는 VEGF의 발현에 acitretin의 효과를 조사하기 위한 것이었다. 우리는 10명의 건선염 피부환자와 대조군으로 3명의 정상인 피부에 acitretin의 치료 전과 후의 VEGF의 발현량을 비교하였다. 치료 전 대조군인 정상인 피부에서보다 건선염 피부환자에서 VEGF의 발현은 명백히 높은 수준이었다. 건선염 피부환자에서 VEGF의 발현량은 acitretin 치료 후 치료 전과 비교시 감소되었다. Acitretin은 건선 피부에서 VEGF와 같은 혈관 신생 유도 인자의 발현을 감소 시켜 신생혈관형성에 있어 억제의 효과가 있음을 나타낸다. 우리는 신생혈관 관점에서 acitretin이 건선에 대한 치료 수단이 될 수 있다는 것을 제안한다. Psoriasis is a well known disorder of keratinization. In this disease, several reports revealed that dermal micro vessels are increased and angiogenic factors such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are over-expressed. Angiogenesis may play an important role in the progression of psoriasis. Acitretin is widely used as an anti-psoriatic drug because of its potent action on keratinocyte growth and differentiation, but its effects on angiogenesis are uncertain. The goal of this immunohistochemical study was to investigate the effects of acitretin on the expression of VEGF in psoriatic lesions of the skin. We compared the expression levels of VEGF between pre- and post-acitretin treated skin - 10 psoriatic skin lesions and 3 normal (control) skins. The expressions of VEGF in psoriatic skin lesions were significantly higher than in normal control skin. The expressions of VEGF in psoriatic skin lesions post-treatment were lower than those pre-treatment. Acitretin revealed inhibitory effects on angiogenesis by reducing the expression of angiogenic factors such as VEGF in psoriatic skin lesions. We suggest that acitretin may be useful in therapeutic approaches to psoriasis management, possibly related to angiogenesis.

Komorbiditäten bei Psoriasis vulgaris

Epidemiologic data document not only a higher prevalence of joint involvement among psoriasis patients than previously thought, but also an association with numerous other diseases, including depression, smoking, alcoholism, Crohn's disease, and metabolic syndrome. The resulting increased cardiovascular mortality is of particular clinical importance, and its pathogenetic link as a complication of the psoriatic inflammation is well recognized. Thus, we need to re-invent the management of psoriasis: Dermatologists are not only the sentinel regarding the early diagnosis of psoriatic arthritis, but also of metabolic complications such as dyslipidemia or diabetes. Moreover, they need to keep in mind interactions between (systemic) anti-psoriatic drugs and the co-medication of their patients as well as possible consequences of these co-medications on the course of psoriasis. To successfully accomplish this mission, a comprehensive management concept and ground-breaking research are urgently needed.

Development and Validation of Human Psoriatic Skin Equivalents

Psoriasis is an inflammatory skin disease driven by aberrant interactions between the epithelium and the immune system. Anti-psoriatic drugs can therefore target either the keratinocytes or the immunocytes. Here we sought to develop an in vitro reconstructed skin model that would display the molecular characteristics of psoriatic epidermis in a controlled manner, allowing the screening of anti-psoriatic drugs and providing a model in which to study the biology of this disease. Human skin equivalents generated from normal human adult keratinocytes after air exposure and stimulation by keratinocyte growth factor and epidermal growth factor displayed the correct morphological and molecular characteristics of normal human epidermis whereas the psoriasis-associated proteins, hBD-2, SKALP/elafin, and CK16, were absent. Skin equivalents generated from foreskin keratinocytes were clearly abnormal both morphologically and with respect to gene expression. When normal skin equivalents derived from adult keratinocytes were stimulated with psoriasis-associated cytokines [tumor necrosis factor-alpha, interleukin (IL)-1alpha, IL-6, and IL-22] or combinations thereof, strong expression of hBD-2, SKALP/elafin, CK16, IL-8, and tumor necrosis factor-alpha was induced as shown by quantitative polymerase chain reaction and immunohistochemistry. Retinoic acid but not cyclosporin A was found to inhibit cytokine-induced gene expression at both the mRNA and protein levels. These results illustrate the potential of this disease model to study the molecular pathology and pharmacological intervention in vitro.

Palmoplantar Pustular Psoriasis: Successful Therapy with Efalizumab after Non-response to Infliximab

Sir, Treatment of palmoplantar pustular psoriasis (PPP) is difficult (1). Topical treatment with anti-psoriatic drugs often gives unconvincing results. Even systemic treatments show initial efficacy in only a certain proportion of patients. Other patients are resistant to any kind of therapy. And in other patients, again, adverse events lead to dose reduction or, imperatively, to discontinuation of therapy. The patient described here had a long history of PPP. Even tumour necrosis factor (TNF)-α antibody infliximab, given a short time before caused only transient improvement when applied as monotherapy or in combination with methotrexate. We finally initiated treatment with efalizumab, whereby the condition cleared within 10–12 weeks.

Narrowband UV-B Phototherapy, Alefacept, and Clearance of Psoriasis

To determine whether the addition of 311-nm narrowband UV-B (NB UV-B) phototherapy accelerates and improves the therapeutic efficacy of alefacept, a biological antipsoriatic drug approved for the treatment of moderate to severe psoriasis. Randomized half-body comparison study. Ambulatory section of a university hospital photodermatology unit. Fourteen patients with moderate to severe psoriasis. All patients were treated with 7.5 mg of intravenous alefacept once weekly for 12 weeks. Three times each week, a randomly selected body half (left or right) was treated with NB UV-B light until complete remission, defined as a reduction in the Psoriasis Area Severity Index (PASI) to 3 or lower, was achieved on the irradiated body half. Modified PASI, self-assessed visual analogue scale rating of skin lesions, and self-assessed therapeutic efficacy. After 12 weeks of treatment, the mean PASIs on UV-irradiated and nonirradiated body halves were significantly reduced by 81% and 62%, respectively (P < .001). From week 3 to week 12, the mean PASI was significantly lower on UV-irradiated body halves than on nonirradiated body halves (P < .001). At week 12, PASI reductions of greater than 75% had been achieved significantly more often on UV-irradiated body halves (86%, 12 of 14) than on nonirradiated body halves (43%, 6 of 14), and complete remission had been achieved significantly more often on UV-irradiated body halves (43%, 6 of 14) than on nonirradiated body halves (0 of 14) (McNemar test P = .03). In this randomized half-side comparison of alefacept with and without phototherapy for psoriasis, alefacept with NB UV-B phototherapy accelerated and improved the clearance of psoriasis. This suggests a promising future for this combination as antipsoriatic therapy.

Isolation and Identification of Anthralin From the Roots of Rhubarb Plant (Rheum palmatum)

Anthralin is medically and chemically an important compound which can be found in rhubarb roots. Anthralin and anthralin derivatives have been used as antipsoriatic drugs. In this research, pure anthralin was isolated from the rhubarb roots by maceration and Soxhlet extraction methods in various polar and non‐polar solvents. Successive TLC and column chromatography on silica gel with chloroform as the mobile phase afforded two distinct fractions with Rf= 0.54 and 0.61. The 1HNMR, 13CNMR, IR, UV and MS spectra showed that the fraction with Rf= 0.61 was anthralin. In both methods, methanol was found to be the most suitable solvent for extraction.

Identification of avarol derivatives as potential antipsoriatic drugs using an in vitro model for keratinocyte growth and differentiation

Avarol, a marine sesquiterpenoid hydroquinone, and 14 avarol derivatives have shown interesting anti-inflammatory properties in previous studies. In this study, avarol and derivatives were evaluated in high-throughput keratinocyte culture models using cytokeratin 10 and SKALP/Elafin expression as markers for respectively normal and psoriatic differentiation. Avarol and five of its derivatives ( 5, 10, 13, 14 and 15) were selected for further study. Only 10, 13, 14 and 15 were able to inhibit keratinocyte cell growth. Changes in expression levels of 22 genes were assessed by quantitative real time PCR (qPCR). From these genes, TNFα mRNA levels showed the strongest changes. For compound 13, 15 and dithranol (used as a model antipsoriatic drug), a dose-dependent downregulation of TNFα mRNA was found. The changes in TNFα mRNA were confirmed at the protein level for compound 13. Additionally, this compound was able to reduce also IL-8 and COX-2 mRNA levels and this effect was correlated with a reduction in COX-2 protein expression. The mechanism of action of this compound involves at least the inhibition of NF-κB-DNA binding activity. In conclusion, our high-throughput screening models in combination with quantitative assessment of changes in gene expression profiles identified the avarol derivative 13, a benzylamine derivative of avarol at the 4′ position of benzoquinone ring, as an interesting anti-psoriatic drug candidate that inhibits keratinocyte cell growth and TNFα and COX-2 expression.

Potent antagonism of calmodulin activity in vitro, but lack of antiproliferative effects on keratinocytes by the novel leukotriene biosynthesis inhibitor MK-886.

MK-886, a leukotriene biosynthesis inhibitor, which prevents the translocation and activation of 5-lipoxygenase, has been proposed as an effective drug for the treatment of inflammatory disorders, including psoriasis. In the present study, we investigated the effects of MK-886 on calmodulin as a potential target protein of anti-inflammatory drug activity, and on the proliferation of cultured human keratinocytes, a calmodulin-dependent cellular response with indicative value for antipsoriatic drug activity. Despite potent calmodulin-antagonistic activity in vitro, MK-886 failed to block cell proliferation in a human keratinocyte line, whereas trifluoperazine, a well characterized calmodulin antagonist with similar effects on calmodulin activity in our in vitro assays, inhibited cell proliferation in a dose-dependent manner. Further investigations on the mechanism of action revealed that, in contrast with trifluoperazine, calmodulin antagonism by MK-886 in vitro is likely to be mediated at the level of the allosteric calmodulin-recognition site of phosphodiesterase, rather than by binding to calmodulin itself. Therefore, our data do not conflict with the proposed role of calmodulin in the regulation of cell proliferation, but demonstrate that drug-induced antagonism of calmodulin, detected by inhibition of calmodulin-dependent enzymes in vitro, is not necessarily linked to antiproliferative activity in human keratinocytes.

The expression of keratinocyte growth factor receptor (FGFR2‐IIIb) correlates with the high proliferative rate of HaCaT keratinocytes

Keratinocyte growth factor receptor (KGFR = FGFR2-IIIb) is a tyrosine kinase receptor expressed by keratinocytes, which mediates the effects of fibroblast growth factors (FGF). There are contradictory data in the literature regarding the role of FGFR2-IIIb during the proliferation/differentiation programme of keratinocytes. In this study, we aimed to investigate whether overexpression of FGFR2-IIIb may have a role in the regulation of keratinocyte proliferation. We analysed the expression of FGFR2-IIIb in an in vitro HaCaT model system representing different stages of proliferation and differentiation of keratinocytes. Real-time RT-PCR and Western blot analyses demonstrated a correlation between FGFR2-IIIb mRNA and protein expression and the proportion of cells in S/G2/M phase in synchronized HaCaT keratinocytes and thus with proliferation activity (r = 0.96). After treatment with the antipsoriatic drug, dithranol, FGFR2-IIIb is downregulated dose dependently both at mRNA and protein levels. Moreover, when the rate of proliferation is decreased by the lack of cell attachment to the culturing surface, FGFR2-IIIb mRNA (P = 0.0315) and protein expressions were also reduced (P = 0.0242), while a differentiation marker, keratin 10, mRNA (P = 0.0003) and protein levels (P = 0.001) were increased (r = -0.92). Based on our results we conclude that FGFR2-IIIb expression in HaCaT keratinocytes corresponds with the proliferative activation of the cells and is not related to the differentiation programme.

Evaluation of the anti-proliferative properties of selected psoriasis-treating Chinese medicines on cultured HaCaT cells

Psoriasis is a chronic inflammatory skin disorder, which affects approximately 2–3% of the population worldwide. The current conventional therapy cannot offer satisfactory clinical results for most of the patients, largely due to the fact that many anti-psoriatic drugs have serious side effects and psoriasis is prone to developing drug resistance after long term exposure. Traditionally, Chinese herbal medicine has been extensively used to treat psoriasis and produced promising clinical results; however, its underlying mechanisms of action have not been systematically investigated. The aim of this study was to investigate those Chinese medicinal materials, which are commonly prescribed in Chinese medicine practice for psoriasis, for their anti-proliferative effects on HaCaT cells in vitro. Sixty Chinese medicinal materials were selected and extracted with 80% aqueous ethanol. The dry extracts were evaluated for their anti-proliferative activities by microplate SRB and MTT assays. Three Chinese medicinal materials i.e. the root of Rubia cordifolia L. (Rubiaceae), Realgar and the rhizome of Coptis chinensis Franch. (Ranunculaceae) were found to have significant anti-proliferative effects, with IC 50 being 1.4, 6.6 and 23.4 μg/ml, respectively as measured by MTT assay. While Realgar was also able to modestly inhibit the growth of Hs-68 cells in vitro, Rubia cordifolia and Coptis chinensis did not exert cytotoxicity to this human fibroblast cell line.

Psoriasis and hepatitis C treated with anti-TNF alpha therapy (etanercept)

The treatment of severe psoriasis in patients with concomitant hepatitis-C virus infection is quite difficult because several systemic anti-psoriatic drugs are contraindicated owing to their liver toxicity. Recent observations in the literature suggest that etanercept is an effective and safe therapy for this setting of patients. We present a 45-year-old man with extensive plaque psoriasis and concurrent hepatitis C, successfully treated with 12-month etanercept monotherapy. Regular controls of hepatic enzymes and viral load during the treatment disclosed no worsening of baseline values. This case confirms that etanercept may be a safe option for the therapy of patients with psoriasis and hepatitis-C virus infection.

Alefacept: a safety profile

Alefacept is a selective immunomodulating, antipsoriatic drug that blocks the LFA-3/CD2 interaction necessary for the activation and proliferation of memory effector T cells by binding to CD2 expressed on the T cell surface. Because the CD4+ count is reduced by alefacept, it is recommended that this count be monitored on a regular basis to ensure that it does not drop below 250 cells/μl. Few side effects have been related to the use of alefacept that differ from placebo even when CD4+ counts drop below 250 cells/μl. The side effects that have been reported are minor and include: headache, nasopharyngitis, rhinitis, influenza, upper respiratory tract infections, pruritus, arthralgias, fatigue, nausea, accidental injury and increases in liver enzymes. Serious infections and malignancies do not appear linked to the use of alefacept. The percentage of patients who developed antibodies against alefacept is very low. Alefacept is a very safe biological therapy for moderate-to-severe chronic plaque psoriasis with few side effects reported. The utility of checking CD4 counts while administering alefacept for 12 weeks appears minimal.

A practical synthesis of L-threo-dihydrosphingosine (safingol), an antineoplastic and antipsoriatic agent

LS-threo-Dihydrosphingosine, an antineoplastic and antipsoriatic drug, has been synthesized by the Henri reaction of hexadecanal and 2-nitroethanol followed by catalytic hydrogenation of the dl-threo-2-nitro-1,3-octadecanediol and resolution of the racemic dl-threo-dihydrosphingosine. Selection of solvents for recrystallization of mixtures of dl-threo and erythro diastereoisomers proved to be of critical importance for the 100-gram scale preparation of the target compound.

Inverse Regulation of the Nuclear Factor-κB Binding to the p53 and Interleukin-8 κB Response Elements in Lesional Psoriatic Skin

Nuclear factor-kappaB (NF-kappaB) is an inducible nuclear transcription factor regulating a range of cellular processes. An imbalance of the DNA binding activity of NF-kappaB may, therefore, be part of the pathophysiological mechanisms in psoriasis. The purpose of this study was to determine the NF-kappaB DNA binding activity in psoriatic skin using three different kappaB sites and to determine how DNA binding activity was modulated by the anti-psoriatic drug calcipotriol. By electrophoretic mobility shift assay, we demonstrated that the NF-kappaB DNA binding to the p53 kappaB site was decreased, whereas the NF-kappaB DNA binding to the interleukin-8 (IL-8) kappaB site was increased in lesional psoriatic skin compared with non-lesional psoriatic skin. No regulation was seen on the NF-kappaB DNA binding to the major histocompatibility complex class I kappaB site. These changes were paralleled by a similar decrease in p53 expression and an increase in IL-8 expression in involved psoriatic skin compared with uninvolved skin as determined by quantitative RT-PCR. The alteration in NF-kappaB DNA binding activity was neither accompanied by any change in the expression of the inhibitor kappaB (IkappaB) kinases, IKKalpha, IKKbeta, and IKKgamma nor in the expression of the NF-kappaB inhibitor proteins, IkappaBalpha and IkappaBbeta. Immunofluorescence analysis revealed that p65 was sequestered in the cytoplasm of keratinocytes, whereas p50 exhibited a cytoplasmic as well as a nuclear localization. Interestingly, this distribution of p50 and p65 was similar in lesional and non-lesional psoriatic skin. Topical application of calcipotriol to lesional psoriatic skin for 4 d resulted in increased NF-kappaB binding to the p53 kappaB site and decreased NF-kappaB binding to the IL-8 kappaB site. Taken together, our data demonstrate that the NF-kappaB DNA binding activity is regulated in a specific manner in psoriatic skin depending on the kappaB sites investigated, and that topical treatment of psoriatic skin normalizes the abnormal NF-kappaB binding activity seen in lesional psoriatic skin.

Cannabinoids, loratadine and allopurinol as novel additions to the antipsoriatic ammunition

As the current antipsoriatic medications are commonly associated with deleterious side-effects, a determined search for safer agents, which could be used alone or in combination with current antipsoriatic drugs, would be very imperative. Psoriasis is believed to be characterized by a type 1 cytokine pattern; interferon-γ, interleukin (IL)-2 and tumour necrosis factor (TNF)-α are predominantly expressed in this disorder. Nitric oxide, reactive oxygen species, histamine, leukotriene B4, and decreased keratinocyte cyclic adenosine monophosphate/cyclic guanosine monophosphate (cAMP/cGMP) ratio are supposed to play roles in the pathogenesis of this disorder. Based on the immunopathogenesis of psoriasis, this paper introduces three novel, potential treatments for this clinical conundrum: (i) cannabinoids, which exert inhibitory effects on antigen processing and macrophage/T–cell interaction and also on the release of IL-2, TNF-α and nitric oxide from immune cells; (ii) loratadine, which is an antihistamine capable of increasing the cAMP/cGMP ratio and the production of leukotriene B4; and (iii) allopurinol, which scavenges free radicals, inhibits the production of TNF-α, and down-regulates the expression of intercellular adhesion molecule-1 and P2X7 receptors on monocytes/macrophages, which are involved in antigen presentation and production of the inflammatory response, respectively. Importantly, allopurinol, especially in combination with cyclosporin, has been shown to be effective against experimental autoimmune uveitis, which, like psoriasis, is a cell-mediated autoimmune disorder.