Plant extracts for the topical management of psoriasis: a systematic review and meta-analysis

Modulating AHR function offers exciting therapeutic potential in gut immunity and inflammation

Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a classical exogenous synthetic ligand of AHR that has significant immunotoxic effects. Activation of AHR has beneficial effects on intestinal immune responses, but inactivation or overactivation of AHR can lead to intestinal immune dysregulation and even intestinal diseases. Sustained potent activation of AHR by TCDD results in impairment of the intestinal epithelial barrier. However, currently, AHR research has been more focused on elucidating physiologic AHR function than on dioxin toxicity. The appropriate level of AHR activation plays a role in maintaining gut health and protecting against intestinal inflammation. Therefore, AHR offers a crucial target to modulate intestinal immunity and inflammation. Herein, we summarize our current understanding of the relationship between AHR and intestinal immunity, the ways in which AHR affects intestinal immunity and inflammation, the effects of AHR activity on intestinal immunity and inflammation, and the effect of dietary habits on intestinal health through AHR. Finally, we discuss the therapeutic role of AHR in maintaining gut homeostasis and relieving inflammation.

Aloe vera-loaded natural rubber latex dressing as a potential complementary treatment for psoriasis

Psoriasis is a disease that causes keratinocytes to proliferate ten times faster than normal, resulting in chronic inflammation and immune cell infiltration in the skin. Aloe vera (A. vera) creams have been used topically for treating psoriasis because they contain several antioxidant species; however, they have several limitations. Natural rubber latex (NRL) has been used as occlusive dressings to promote wound healing by stimulating cell proliferation, neoangiogenesis, and extracellular matrix formation. In this work, we developed a new A. vera-releasing NRL dressing by a solvent casting method to load A. vera into NRL. FTIR and rheological analyzes revealed no covalent interactions between A. vera and NRL in the dressing. We observed that 58.8 % of the loaded A. vera, present on the surface and inside the dressing, was released after 4 days. Biocompatibility and hemocompatibility were validated in vitro using human dermal fibroblasts and sheep blood, respectively. We observed that ~70 % of the free antioxidant properties of A. vera were preserved, and the total phenolic content was 2.31-fold higher than NRL alone. In summary, we combined the antipsoriatic properties of A. vera with the healing activity of NRL to generate a novel occlusive dressing that may be indicated for the management and/or treatment of psoriasis symptoms simply and economically.

Signaling pathways and targets of natural products in psoriasis treatment

Aim: Psoriasis is a common chronic inflammatory skin disorder, which has adverse effects on patients’ quality of life. Natural products exhibit significant therapeutic capacities with small side effects and might be preferable alternative treatments for patients with psoriasis. This study summarizes the signaling pathways with the potential targets of natural products and their efficacy for psoriasis treatment. Methods: The literature for this article was acquired from PubMed and Web of Science, from January 2010 to December 2020. The keywords for searching included “psoriasis” and “natural product”, “herbal medicine”, “herbal therapy”, “medicinal plant”, “medicinal herb” or “pharmaceutical plant”. Results: Herbal extracts, natural compounds, and herbal prescriptions could regulate the signaling pathways to alleviate psoriasis symptoms, such as T helper 17 (Th17) differentiation, Janus kinase (JAK)/signal transducer and activator of transcription (STAT), nuclear factor-kappa B (NF-κB), mitogen‑activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), and other signaling pathways, which are involved in the inflammatory response and keratinocyte hyperproliferation. The anti-psoriatic effect of natural products in clinical trials was summarized. Conclusions: Natural products exerted the anti-psoriatic effect by targeting multiple signaling pathways, providing evidence for the investigation of novel drugs. Further experimental research should be performed to screen and characterize the therapeutic targets of natural products for application in psoriasis treatment.

Phosphoproteomics Reveals Regulation of Secondary Metabolites in Mahonia bealei Exposed to Ultraviolet-B Radiation

Mahonia bealei (M. bealei) is a traditional Chinese medicine containing a high alkaloid content used to treat various diseases. Generally, only dried root and stem are used as medicines, considering that the alkaloid content in M. bealei leaves is lower than in the stems and roots. Some previous research found that alkaloid and flavonoid contents in the M. bealei leaves may increase when exposed to ultraviolet B (UV-B) radiation. However, the underlying mechanism of action is still unclear. In this study, we used titanium dioxide material enrichment and mass-based label-free quantitative proteomics techniques to explore the effect and mechanism of M. bealei leaves when exposed to UV-B treatment. Our data suggest that UV-B radiation increases the ATP content, photosynthetic pigment content, and some enzymatic/nonenzymatic indicators in the leaves of M. bealei. Moreover, phosphoproteomics suggests phosphoproteins related to mitogen-activated protein kinase (MAPK) signal transduction and the plant hormone brassinosteroid signaling pathway as well as phosphoproteins related to photosynthesis, glycolysis, the tricarboxylic acid cycle, and the amino acid synthesis/metabolism pathway are all affected by UV-B radiation. These results suggest that the UV-B radiation activates the oxidative stress response, MAPK signal transduction pathway, and photosynthetic energy metabolism pathway, which may lead to the accumulation of secondary metabolites in M. bealei leaves.

2,4-Dimethoxy-6-Methylbenzene-1,3-diol, a Benzenoid From Antrodia cinnamomea, Mitigates Psoriasiform Inflammation by Suppressing MAPK/NF-κB Phosphorylation and GDAP1L1/Drp1 Translocation

Antrodia cinnamomea exhibits anti-inflammatory, antioxidant, and immunomodulatory activities. We aimed to explore the antipsoriatic potential of 2,4-dimethoxy-6-methylbenzene-1,3-diol (DMD) derived from A. cinnamomea. The macrophages activated by imiquimod (IMQ) were used as the cell model for examining the anti-inflammatory effect of DMD in vitro. A significantly high inhibition of IL-23 and IL-6 by DMD was observed in THP-1 macrophages and bone marrow-derived mouse macrophages. The conditioned medium of DMD-treated macrophages could reduce neutrophil migration and keratinocyte overproliferation. DMD could downregulate cytokine/chemokine by suppressing the phosphorylation of mitogen-activated protein kinases (MAPKs) and NF-κB. We also observed inhibition of GDAP1L1/Drp1 translocation from the cytoplasm to mitochondria by DMD intervention. Thus, mitochondrial fission could be a novel target for treating psoriatic inflammation. A psoriasiform mouse model treated by IMQ showed reduced scaling, erythema, and skin thickening after topical application of DMD. Compared to the IMQ stimulation only, the active compound decreased epidermal thickness by about 2-fold. DMD diminished the number of infiltrating macrophages and neutrophils and their related cytokine/chemokine production in the lesional skin. Immunostaining of the IMQ-treated skin demonstrated the inhibition of GDAP1LI and phosphorylated Drp1 by DMD. The present study provides insight regarding the potential use of DMD as an effective treatment modality for psoriatic inflammation.

Chinese Medicine Formula PSORI-CM02 Alleviates Psoriatic Dermatitis via M-MDSCs and Th17 Crosstalk

Psoriasis is a chronic inflammatory skin disease that is associated with multiple coexisting conditions. Extensive literature suggests that psoriasis is a T-cell-mediated condition, and its pathogenesis is related to dysfunction of the immune system. Myeloid-derived suppressor cells (MDSCs) are a group of heterogeneous myeloid cells that have suppressive effects on T cells. MDSCs are present at very low levels in healthy individuals but can substantially expand in tumours or inflammatory conditions. PSORI-CM02, a Chinese medical formula designed based on the Chinese medicine theory (Blood Stasis), has been prescribed extensively for psoriasis therapy and shows a stable clinical effect and safety. This study discusses the mechanisms of MDSCs involved in disease development and therapeutic progress. Our data provides evidence that monocytic myeloid-derived suppressor cells (M-MDSCs) play a role in IMQ-induced psoriatic dermatitis. Functional characterization and correlation analysis indicated that MDSCs are positively correlated with Th17 cells. PSORI-CM02 alleviated IMQ-induced psoriatic dermatitis and suppressed the proliferation of Th17 cells via M-MDSC-induced Arg1 upregulation, suggesting M-MDSCs could be a novel therapeutic target for psoriasis, and PSORI-CM02 exerted its effects via the perturbation of M-MDSCs and Th17 cell crosstalk.

Effects of Aloe vera in adults with mucocutaneous problems: A systematic review and meta-analysis

AIMS

To analyse the different types of Aloe vera (AV) effects on various mucocutaneous problems among adults.

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

An exhaustive scanning of PubMed, Medline, ScienceDirect, and Google Scholar databases was conducted from January 2000-December 2019.

REVIEW METHODS

Randomized controlled trials (RCTs) publishing reports on the effects of AV in various mucocutaneous problems, psoriasis, burn, wound-healing were included. The standardized mean differences (SMD) with 95% confidence Intervals (CIs) were determined for the main outcomes, heterogeneity was analysed using the I² test and the risk of bias in the studies was reviewed by the Cochrane risk of bias assessment tool.

RESULTS

The study included 23 trials with a total of 4,023 participants. Six trials were included in the meta-analysis. The results indicated no significant differences in pain scores as assessed by the Visual Analog Scale (VAS) (SMD = 0.11, 95% CI: -0.37 to 0.59). The Psoriasis Area Severity Index (PASI) scores were significantly lower following AV gel application in two of the studies (SMD = -1.32 95% CI: -1.86 to -0.78). Considering results in a systematic manner, AV accelerated tissue epithelialization and wound-healing process (N = 3), reduced oral mucositis (N = 3), and improved quality of life (N = 1).

CONCLUSION

AV might have beneficial effects in reducing pain scores and the severity of mucocutaneous problems compared with placebo, especially with limited mild to moderate adverse effects.

IMPACT

AV may be used as an alternative and integrative approach to reducing symptom severity in mucocutaneous problems and the wound-healing process. High quality and well-designed RCTs are still needed to elucidate the effects of AV in a variety of dosages and forms among adults with mucocutaneous problems.

Joint AAD-NPF Guidelines of care for the management and treatment of psoriasis with topical therapy and alternative medicine modalities for psoriasis severity measures

Psoriasis is a chronic, inflammatory, multisystem disease that affects up to 3.2% of the United States population. This guideline addresses important clinical questions that arise in psoriasis management and care and provides recommendations based on the available evidence. The treatment of psoriasis with topical agents and with alternative medicine will be reviewed, emphasizing treatment recommendations and the role of dermatologists in monitoring and educating patients regarding benefits as well as risks that may be associated. This guideline will also address the severity assessment methods of psoriasis in adults.

Topical Delivery of Curcumin by Choline-Calix[4]arene-Based Nanohydrogel Improves Its Therapeutic Effect on a Psoriasis Mouse Model

Curcumin (CUR) has shown remarkable efficacy in the treatment of skin diseases, but its effective transdermal delivery is still a major challenge and stimulates interest in the design of novel systems for CUR dispersion, preservation, and delivery facilitation to the deeper layers of the skin. The present work aimed to investigate the potential of a nanohydrogel, formed by a micellar choline-calix[4]arene amphiphile (CALIX) and CUR, in the treatment of skin diseases through an imiquimod (IMQ)-induced psoriasis model. Psoriasis plaques are associated with aberrant keratinization, abnormal distribution of tight junctions (TJs) proteins, and enhanced expression of inflammatory markers. The nanohydrogel restored the normal distribution of TJs proteins ZO1 and occludin and reduced the expression of TNF-α and inducible nitric oxide synthetase (iNOS) compared to the untreated IMQ group. The novelty lies in the calix[4]arene-based nanohydrogel as a potential new soft material for the topical skin delivery of CUR. The nanohydrogel, due to its physicochemical and mechanical properties, enhances the drug water-solubility, preserves CUR from rapid degradation, and eases the local skin administration and penetration.

Our Choice: study protocol for a randomized controlled trial for optimal implementation of psoriasis treatment by the integration of Chinese and western medicine

BACKGROUND

Plaque psoriasis is a refractory inflammatory skin disease. The common therapies used to treat plaque psoriasis in traditional Chinese medicine (TCM) and western medicine (WM) have distinct characteristics and advantages. Although a combination of TCM and WM therapies, adjusted to the clinical situation, is widely used, there are no systematic studies on the hierarchical selection of this treatment combination based on the severity of skin lesions. We therefore designed a randomized clinical trial to focus on the sequence of internal and external treatments of TCM in patients with mild-to-moderate plaque psoriasis and to optimize the integration of Chinese and western medicine for the treatment of patients with severe plaque psoriasis, thereby achieving high-level clinical evidence and establish treatment norms for the integrated use of Chinese and western medicines.

METHODS

In this proposed multicenter, single-blinded, randomized controlled trial, 108 patients with mild-to-moderate plaque psoriasis will be randomly assigned to two groups in a 1:1 ratio to receive either internal or external TCM treatment, and 270 patients with severe plaque psoriasis will be randomly assigned to three groups in a 1:1:1 ratio to receive treatment with TCM or WM, or TCM + WM. All enrolled patients will receive 8 weeks of treatment. Follow-up assessments will be done 8 weeks after the treatment. The primary outcome of this study is the evaluation of efficacy and relapse rate, based on the Psoriasis Area and Severity Index, and the secondary outcome measures include determination of the affected body surface area, physician's global assessment, pruritus scores (determined using a visual analog scale), TCM symptom score, Dermatology Life Quality Index, patient-reported quality of life score and incidence of serious adverse events.

DISCUSSION

This study will provide high-level clinical evidence for internal and external TCM treatment optimization and will contribute to establishing norms for the integration of Chinese and western Medicines.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03941431. Registered on 8 May 2019.

Short-term and long-term outcomes of indigo naturalis treatment for inflammatory bowel disease

BACKGROUND AND AIM

Indigo naturalis (IN) is a traditional Chinese herbal medicine reported to be effective in inducing remission in ulcerative colitis (UC). We conducted a retrospective observational study to investigate the efficacy and safety of IN for induction and maintenance therapy in patients with inflammatory bowel disease.

METHODS

Data were collected from the electric medical records of patients with inflammatory bowel disease who had started IN treatment between March 2015 and April 2017 at Kyushu University Hospital. Clinical response and remission rates were assessed based on the clinical activity index determined by Rachmilewitz index or Crohn's disease (CD) activity index. Cumulative IN continuation rates were estimated using the Kaplan-Meier method. Overall adverse events (AEs) during follow-up were also analyzed.

RESULTS

Seventeen UC patients and eight CD patients were enrolled. Clinical response and remission rates at week 8 were 94.1% and 88.2% in UC patients and 37.5% and 25.0% in CD patients, respectively. Clinical remission rates, as assessed through non-responders imputation analyses at weeks 52 and 104, were 76.4% and 70.4% in UC patients and 25.0% and 25.0% in CD patients, respectively. Ten patients (40%) experienced AEs during follow-up. Three patients (12%) experienced severe AEs, including acute colitis requiring hospitalization in two patients and acute colitis with intussusception requiring surgery in one patient.

CONCLUSIONS

Indigo naturalis showed favorable therapeutic efficacy in UC, whereas its therapeutic efficacy in CD appeared to be modest. The risk of severe AEs should be recognized for IN treatment.

Auricular acupressure as a complementary therapy for psoriasis vulgaris: study protocol for a multicenter randomized controlled trial

INTRODUCTION

Psoriasis vulgaris is a common skin disease characterized by persistent localized erythematous scaly plaques, typically on the elbows, knees, and scalp. It is an immune-abnormal disease that progresses slowly over a long period with frequent symptom recurrence. Current studies have shown that acupuncture is an effective therapy for psoriasis. However, the scientific evidence of the efficacy of auricular acupressure treatment for patients with psoriasis is still insufficient. Therefore, we designed a randomized controlled clinical trial to investigate the effect, safety, and cost-effectiveness of auricular acupressure in addition to medication in patients with psoriasis.

METHODS AND ANALYSIS

This on-going study is a two-arm parallel, assessor-blinded, randomized controlled trial in which 180 participants with psoriasis will be recruited and then randomly allocated into two groups in a 1:1 ratio. Equal randomization will be conducted using a computer-generated random allocation sequence. Participants in the intervention group will receive auricular acupressure treatment once per week for 4 weeks, and calcipotriol betamethasone ointment for topical use once daily for 4 weeks. Participants in the control group will receive only calcipotriol betamethasone ointment treatment once daily for 4 weeks. All patients will be followed up for 12 weeks. The primary outcome is relapse rate. The secondary outcomes include time to relapse, rebound rate, time to new onset, Psoriasis Area and Severity Index score improvement rate, body surface area affected, a visual analogue scale, and Dermatology Life Quality Index. Cost-effectiveness analysis will be carried out from a health and community care provider perspective.

DISCUSSION

This multicenter randomized controlled trial will provide important clinical evidence for the effect and safety of auricular acupressure as a complementary therapy in patients with psoriasis.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR-TRC-14004916 . Registered on 20 May 2014. This protocol is version 3.0 which was updated on 24 September 2016.

Apoptotic or Antiproliferative Activity of Natural Products against Keratinocytes for the Treatment of Psoriasis

Natural products or herbs can be used as an effective therapy for treating psoriasis, an autoimmune skin disease that involves keratinocyte overproliferation. It has been demonstrated that phytomedicine, which is used for psoriasis patients, provides some advantages, including natural sources, a lower risk of adverse effects, and the avoidance of dissatisfaction with conventional therapy. The herbal products’ structural diversity and multiple mechanisms of action have enabled the synergistic activity to mitigate psoriasis. In recent years, the concept of using natural products as antiproliferative agents in psoriasis treatment has attracted increasing attention in basic and clinical investigations. This review highlights the development of an apoptotic or antiproliferatic strategy for natural-product management in the treatment of psoriasis. We systematically introduce the concepts and molecular mechanisms of keratinocyte-proliferation inhibition by crude extracts or natural compounds that were isolated from natural resources, especially plants. Most of these studies focus on evaluation through an in vitro keratinocyte model and an in vivo psoriasis-like animal model. Topical delivery is the major route for the in vivo or clinical administration of these natural products. The potential use of antiproliferative phytomedicine on hyperproliferative keratinocytes suggests a way forward for generating advances in the field of psoriasis therapy.

Vitis vinifera L. Leaf Extract Inhibits In Vitro Mediators of Inflammation and Oxidative Stress Involved in Inflammatory-Based Skin Diseases

Psoriasis is a chronic cutaneous condition characterized by the release of pro-inflammatory mediators and oxidative stress. The reduction of these factors is currently the most effective strategy to inhibit the symptoms of pathology. Antioxidants from natural sources are increasingly used to improve skin conditions. Dried red leaves from grapevine (Vitis vinifera L., cv Teinturiers) showed anti-inflammatory and anti-bacterial activities, but their possible effects on keratinocytes have not been previously investigated. In this study we tested the ability of a water extract from grapevine leaves (VVWE) to inhibit inflammatory conditions in human keratinocytes (HaCaT cells), challenged with proinflammatory (tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS)) or prooxidant (ultraviolet B radiation (UVB) or H₂O₂) mediators. VVWE inhibited interleukin-8 (IL-8) secretion induced by proinflammatory stimuli, acting on the IL-8 promoter activity, but the effect was lower when prooxidant mediators were used. The effect was partly explained by the reduction of nuclear factor-κB (NF-κB)-driven transcription and nuclear translocation. Furthermore, vascular endothelial growth factor (VEGF) secretion, a regulator of angiogenesis, was inhibited by VVWE, but not matrix metalloproteinase-9 (MMP-9), a protease involved in matrix remodeling. VVWE, assayed on Franz diffusion cell system, showed a marked reduction of High Performance Liquid Chromatography (HPLC)-identified compounds. Pure molecules individually failed to reduce TNF-α-induced IL-8 release, suggesting synergistic effects or the presence of other bioactive compounds still unknown.

Current new challenges in the management of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory condition of the gastrointestinal tract. Although the cause of UC is postulated to be multifactorial in nature, including genetic predisposition, epithelial barrier defects, dysregulation of immune responses, and environmental factors, the specific pathogenesis of UC is still incompletely understood. In the treatment of UC so far, a method of suppressing immunity and treating it has been mainstream. Immunosuppressant drugs, including thiopurines (azathioprine or 6-mercaptopurine), anti-tumor necrosis factor-α (anti-TNF-α) antibody (infliximab and adalimumab), and calcineurin inhibitor, can be used in treat patients with corticosteroid-dependent and/or corticosteroid-refractory moderate-to-severe UC. Recently, in addition to such a conventional therapeutic agent, golimumab, which is the first transgenic human monoclonal anti-TNF-α antibody to be fabricated, anti α-4/β-7 integrin antibody, and Janus kinase inhibitor have been reported to novel immunosuppressant therapy. Furthermore, other treatments with unique mechanisms different from immunosuppression, have also been suggested, including fecal microbiota transplantation and Indigo naturalis, which is a Chinese herbal medicine. We compared the features and efficacy of these new treatments. In this issue, the features and treatment options for these new treatments is reviewed.

Effects of aloe polysaccharide, a polysaccharide extracted from Aloe vera, on TNF‑α‑induced HaCaT cell proliferation and the underlying mechanism in psoriasis

Aloe vera is a traditional wound‑healing medicine used for the treatment of skin disorders. Aloe polysaccharide (APS) is the main macromolecule of Aloe vera, which contributes to its function. Psoriasis is an immune‑mediated chronic inflammatory disease, which affects 2‑3% of the general population. The conventional remedies used to treat psoriasis demonstrate limited effects; therefore, natural products, including Aloe vera, are being taken into consideration. However, the effects of APS on the treatment of psoriasis and the underlying mechanisms remain to be elucidated. The human keratinocyte cell line HaCaT was used to determine the effects of APS on psoriasis. Cells were randomly divided into five groups: i) Negative control group; ii) tumor necrosis factor (TNF)‑α stimulated psoriasis model group; and iii) APS (20, 40 and 80 µg/ml) pretreated psoriasis groups. Cell viability and proliferation were investigated using the CCK‑8 assay. ELISA and western blotting were applied to study the abundance of interleukin (IL)‑8 and IL‑12 in TNF‑α‑incubated culture medium and APS‑treated HaCaT cells, respectively. In addition, the mRNA expression levels of p65, and the protein expression levels of nuclear factor (NF)‑κB inhibitor‑α (IκBα) and phosphorylated‑p65, were detected by reverse transcription‑quantitative polymerase chain reaction and western blotting, respectively. APS was revealed to significantly reduce TNF‑α‑stimulated elevation of HaCaT cell proliferation in a dose‑dependent manner. The expression levels of inflammatory factors, including IL‑8 and IL‑12, were increased in response to TNF‑α. In addition, the mRNA and protein expression levels of p65 were increased following treatment with TNF‑α. Notably, treatment with APS was demonstrated to significantly attenuate the aforementioned effects in a dose‑dependent manner. Furthermore, IκBα protein expression levels were significantly reduced following treatment with TNF‑α, which was significantly reversed following treatment with APS. In conclusion, these results suggested that APS inhibited TNF‑α‑induced proliferation of keratinocytes and overactivation of the NF‑κB signaling pathway.

Oral Chinese herbal medicine for psoriasis vulgaris: protocol for a randomised, double-blind, double-dummy, multicentre clinical trial

INTRODUCTION

Psoriasis vulgaris is a common skin disease that is characterised by persistent localised erythematous scaly plaques. Yinxieling is a Chinese herbal formula for psoriasis that has been used for more than 20 years in China. To facilitate application, PSORI-CM01 was developed based on the optimisation and simplification of Yinxieling tablets performed in a previous study and in clinical practice. However, the scientific evidence regarding whether PSORI-CM01 is more effective for psoriasis than the original Yinxieling remains insufficient. Therefore, we designed a randomised clinical trial to investigate the effect, safety and cost-effectiveness of PSORI-CM01 granules compared with those of Yinxieling tablets for the treatment of patients with psoriasis.

METHODS AND ANALYSIS

This ongoing study is a two-arm parallel, randomised, double-blind, double-dummy clinical trial. Five hundred and fifty-six participants with psoriasis will be recruited and then randomly allocated into two groups in a 1:1 ratio. Participants in PSORI-CM01 group will receive a 5.5 g granule of PSORI-CM01 two times daily and five placebo tablets three times daily for 12 weeks. The participants in the Yinxieling group will receive five Yinxieling tablets three times daily and a placebo granule two times daily for 12 weeks. The primary outcome is the reduction of the Psoriasis Area and Severity Index. The secondary outcomes include relapse rate, Visual Analogue Scale scores, body surface area and the Dermatology Life Quality Index. Cost-effectiveness analysis will be performed from a health and community care provider perspective.

ETHICS AND DISSEMINATION

This research protocol had been reviewed and approved by the institutional review boards of three trial centres (Guangdong Provincial Hospital of Chinese Medicine (B2014-026-01), Affiliated Hospital of Tianjin Chinese Medicine Academy (2014-KY-001) and Third Hospital of Hangzhou (B2014-026-01)). The findings will be disseminated to the public through conference presentations and open-access journals.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR-TRC-14005185); Pre-results.

Topical Botanical Agents for the Treatment of Psoriasis: A Systematic Review

BACKGROUND

Patients with psoriasis often enquire about the use of numerous botanical therapeutics. It is important for dermatologists to be aware of the current evidence regarding these agents.

METHODS

We conducted a systematic literature search using the PubMed, MEDLINE, and EMBASE databases for controlled and uncontrolled clinical trials that assessed the use of topical botanical therapeutics for psoriasis. The search included the following keywords: 'psoriasis' and 'plant' or 'herbal' or 'botanical'. We also reviewed citations within articles to identify additional relevant sources. We then further refined the results by route of administration and the topical botanical agents are reviewed herein.

RESULTS

A total of 27 controlled and uncontrolled clinical trials addressing the use of topical botanical agents for psoriasis were assessed in this review. We found that the most highly studied and most efficacious topical botanical therapeutics were Mahonia aquifolium, indigo naturalis, aloe vera, and, to a lesser degree, capsaicin. The most commonly reported adverse effects were local skin irritation, erythema, pruritus, burning, and pain. However, the overall evidence for these therapeutics remains limited in quantity and quality.

CONCLUSION

The literature addresses a large number of studies in regard to botanicals for the treatment of psoriasis. While most agents appear to be safe, further research is necessary before topical botanical agents can be consistently recommended to patients.

Indigo Naturalis ameliorates murine dextran sodium sulfate-induced colitis via aryl hydrocarbon receptor activation

BACKGROUND

Indigo Naturalis (IN) is used as a traditional herbal medicine for ulcerative colitis (UC). However, the mechanisms of action of IN have not been clarified. We aimed to evaluate the efficacy of IN for ameliorating colonic inflammation. We further investigated the mechanisms of action of IN.

METHODS

Colitis severity was assessed in dextran sodium sulfate-induced colitis and trinitrobenzene sulfonic acid-induced colitis models with or without the oral administration of IN or indigo, which is a known major component of IN. Colonic lamina propria (LP) mononuclear cells isolated from IN-treated mice were analyzed with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and flow cytometry. LP and splenic mononuclear cells cultured in vitro with IN or indigo were also analyzed. The role of the candidate receptor for indigo, the aryl hydrocarbon receptor (AhR), was analyzed using Ahr-deficient mice.

RESULTS

Colitis severity was significantly ameliorated in the IN and indigo treatment groups compared with the control group. The mRNA expression levels of interleukin (Il)-10 and Il-22 in the LP lymphocytes were increased by IN treatment. The treatment of splenocytes with IN or indigo increased the expression of anti-inflammatory cytokines and resulted in the expansion of IL-10-producing CD4+ T cells and IL-22-producing CD3-RORγt+ cells, but not CD4+Foxp3+ regulatory T cells. The amelioration of colitis by IN or indigo was abrogated in Ahr-deficient mice, in association with diminished regulatory cytokine production.

CONCLUSIONS

IN and indigo ameliorated murine colitis through AhR signaling activation, suggesting that AhR could be a promising therapeutic target for UC.

Natural Compounds for the Treatment of Psoriatic Arthritis: A Proposal Based on Multi-Targeted Osteoclastic Regulation and on a Preclinical Study

BACKGROUND

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis affecting approximately 2% to 3% of the population globally, and is characterized by both peripheral articular manifestations and axial skeletal involvement. Conventional therapies for PsA have not been fully satisfactory, though natural products (NPs) have been shown to be highly effective and represent important treatment options for psoriasis. PsA is a multigenic autoimmune disease with both environmental and genetic factors contributing to its pathogenesis. Accordingly, it is likely that the use of natural compounds with a multi-targeted approach will enable us to develop better therapies for PsA and related disorders.

OBJECTIVE

PsA, either on joint damage or on bone erosion, has been shown to respond to anti-psoriatic pharmacotherapy (APP), APP-like NPs, and their natural compounds. This study aims to uncover specific natural compounds for improved PsA remedies. Specifically, by targeting bone erosion caused by increased osteoclastic bone resorption, we aim to predict the key signaling pathways affected by natural compounds. Further, the study will explore their anti-arthritis effects using an in silico, in vitro, and in vivo approach. Following the signaling pathway prediction, a preclinical efficacy study on animal models will be undertaken. Collectively, this work will discover lead compounds with improved therapeutic effects on PsA.

METHODS

We hypothesize that 9 potential APP-like NPs will have therapeutic effects on arthritis via the modulation of osteoclast bone resorption and signaling pathways. For in silico identification, the Latin name of each NP will be identified using the Encyclopedia of Traditional Chinese Medicine (Encyclopedia of TCM). The biological targets of NPs will be predicted or screened using the Herbal Ingredients' Targets (HIT) database. With the designed search terms, DrugBank will be used to further filter the above biological targets. Protein ANnotation THrough Evolutionary Relationship (PANTHER) will be used to predict the pathways of the natural compound sources. Subsequently, an in vitro sample preparation including extraction, fractionation, isolation, purification, and bioassays with high-speed counter-current chromatography-high-performance liquid chromatography-diode array detection (HSCCC-HPLC-DAD) will be carried out for each identified natural source. In vitro investigations into the effect of NPs on osteoclast signaling pathways will be performed. The experimental methods include cell viability assays, osteoclastogenesis and resorption pit assays, quantitative reverse transcription polymerase chain reaction (RT-PCR), western blot, and luciferase reporter gene assays. Finally, an in vivo preclinical efficacy on a collagen-induced arthritis rat model will be carried out using a treatment group (n=10), a control group (n=10), and a non-arthritis group (n=10). Main outcome measure assessments during intervention include daily macroscopic scores and a digital calipers measurement. Post-treatment tissue measurements will be analyzed by serological testing, radiographic imaging, and histopathological assessment.

RESULTS

Studies are currently underway to evaluate the in silico data and the in vitro effects of compounds on osteoclastogenesis and bone resorption. The preclinical study is expected to start a year following completion of the in silico analysis.

CONCLUSIONS

The in silico rapid approach is proposed as a more general method for adding value to the results of a systematic review of NPs. More importantly, the proposed study builds on a multi-targeted approach for the identification of natural compounds for future drug discovery. This innovative approach is likely to be more precise, efficient, and compatible to identify the novel natural compounds for effective treatment of PsA.

Oral (Systemic) Botanical Agents for the Treatment of Psoriasis: A Review

INTRODUCTION

Patients with psoriasis often use botanical therapies as part of their treatment. It is important for clinicians to be aware of the current evidence regarding these agents as they treat patients.

METHODS

A systematic literature search was conducted using the PubMed, MEDLINE, and EMBASE database for randomized clinical trials assessing the use of botanical therapeutics for psoriasis. The search included the following keywords: "psoriasis" and "plant" or "herbal" or "botanical." Citations within articles were also reviewed to identify relevant sources. The results were then further refined by route of administration, and the oral (systemic) botanical agents are reviewed herein.

RESULTS

A total of 12 controlled and uncontrolled clinical trials addressing the use of oral, systemic botanical agents for psoriasis were assessed in this review. While overall evidence is limited in quantity and quality, HESA-A, curcumin, neem extract, and, to a lesser degree, Traditional Chinese Medicine seem to be the most efficacious agents.

CONCLUSION

The literature addresses a large amount of studies in regards to botanicals for the treatment of psoriasis. While most agents appear to be safe, further research is necessary for evidence-based recommendation of oral botanical agents to psoriasis patients.

Isotetrandrine Reduces Astrocyte Cytotoxicity in Neuromyelitis Optica by Blocking the Binding of NMO-IgG to Aquaporin 4

OBJECTIVE

Neuromyelitis optica (NMO) is a severe neurological demyelinating autoimmune disease that affects the optic nerves and spinal cord with no cure and no FDA-approved therapy. Research over the last decade revealed that the binding of NMO-IgG to the water channel protein astrocyte aquaporin 4 (AQP4) might be the primary cause of NMO pathogenesis. The purpose of this study was to identify potential blockers of NMO-IgG and AQP4 binding.

METHODS

We developed a two-step screening platform consisting of a reporter cell-based high-throughput screen assay and a cell viability-based assay. Purified NMO-IgG from NMO patient serum and transfected Chinese hamster lung fibroblast V79 cells stably expressing human M23-AQP4 were used for primary screening of 40,000 small molecule fractions from 500 traditional Chinese herbs.

RESULTS

Thirty-six positive fractions were identified, of which 3 active fractions (at 50 μg/ml) were found to be from the same Chinese traditional herb Mahonia japonica (Thunb.). A bioactivity-guided method based on a primary screening assay for blocking activity led to the isolation of an active single natural compound, isotetrandrine, from the 3 fractions. Our immunofluorescence staining results showed that isotetrandrine can block NMO-IgG binding to AQP4 without affecting the expression and function of AQP4. It can also inhibit NMO-IgG binding to astrocyte AQP4 in NMO patient sera and block NMO-IgG-dependent complement-mediated cytotoxicity with the IC50 at ∼3 μM.

CONCLUSIONS

The present study developed a cell-based high-throughput screen to identify small molecule inhibitors for NMO-IgG and AQP4 binding, and suggests a potential therapeutic value of isotetrandrine in NMO.

In silico database screening of potential targets and pathways of compounds contained in plants used for psoriasis vulgaris

Reviews and meta-analyses of clinical trials identified plants used as traditional medicines (TMs) that show promise for psoriasis. These include Rehmannia glutinosa, Camptotheca acuminata, Indigo naturalis and Salvia miltiorrhiza. Compounds contained in these TMs have shown activities of relevance to psoriasis in experimental models. To further investigate the likely mechanisms of action of the multiple compounds in these TMs, we undertook a computer-based in silico investigation of the proteins known to be regulated by these compounds and their associated biological pathways. The proteins reportedly regulated by compounds in these four TMs were identified using the HIT (Herbal Ingredients' Targets) database. The resultant data were entered into the PANTHER (Protein ANnotation THrough Evolutionary Relationship) database to identify the pathways in which the proteins could be involved. The study identified 237 compounds in the TMs and these retrieved 287 proteins from HIT. These proteins identified 59 pathways in PANTHER with most proteins being located in the Apoptosis, Angiogenesis, Inflammation mediated by chemokine and cytokine, Gonadotropin releasing hormone receptor, and/or Interleukin signaling pathways. All four TMs contained compounds that had regulating effects on Apoptosis regulator BAX, Apoptosis regulator Bcl-2, Caspase-3, Tumor necrosis factor (TNF) or Prostaglandin G/H synthase 2 (COX2). The main proteins and pathways are primarily related to inflammation, proliferation and angiogenesis which are all processes involved in psoriasis. Experimental studies have reported that certain compounds from these TMs can regulate the expression of proteins involved in each of these pathways.

The inhibitory mechanism by curcumin on the Zac1-enhanced cyclin D1 expression in human keratinocytes

BACKGROUND

ZAC, a zinc finger protein regulating cell cycle arrest and apoptosis, mRNA was found highly expressed in the hyper-proliferative epidermal compartment of psoriatic skin. On the other hand, curcumin has been tried for treatment of psoriasis partly due to its anti-proliferative property.

OBJECTIVES

Since cyclin D1 is a positive regulator for cell-cycle progression and its expression can be inhibited by curcumin, we would like to test whether the expression of cyclin D1 can be affected by Zac1. The cross-talk between curcumin and Zac1 upon the regulation of cyclin D1 expression will also be explored in the HaCaT cell line.

METHODS

Cyclin D1 promoter luciferase reporter was used to measure the transcriptional activity of Zac1 in the absence or presence of curcumin treatment for HaCaT cells. Likewise, RT-PCR, western blotting and flow cytometry were employed to evaluate the expression of Zac1, cyclin D1 and other negative regulators of S phase entry in cell-cycle.

RESULTS

Zac1 enhances the expression of cyclin D1, but curcumin decreases both the expression of Zac1 and cyclin D1. Interestingly, Zac1-induced cyclin D1 promoter activity is abolished by curcumin. Supportively, curcumin indeed exhibits an inhibitory effect to prevent cultured keratinocytes from entry into S phase in the cell cycle.

CONCLUSIONS

These findings revealed that Zac1 modulates not only cell differentiation and apoptosis but also cell proliferation. The experimental results implied that curcumin may inhibit the expression of ZAC, consequently down-regulate the cyclin D1 expression and decelerate cell-cycle progression of psoriatic keratinocytes.

Complementary and alternative medicine for psoriasis: what the dermatologist needs to know

Complementary and alternative medicine (CAM) use is common among patients with psoriasis. CAM modalities include traditional Chinese medicine (TCM), herbal therapies, dietary supplements, climatotherapy, and mind/body interventions. In this review, evidence from clinical trials investigating the efficacy of CAM for psoriasis is reviewed. There is a large amount of evidence from controlled trials that have shown that the combination of TCM with traditional therapies for psoriasis is more efficacious than traditional therapies alone. Herbal therapies that have the most evidence for efficacy are Mahonia aquifolium and indigo naturalis, while there is a smaller amount of evidence for aloe vera, neem, and extracts of sweet whey. Dietary supplementation in patients with psoriasis demonstrates consistent evidence supporting the efficacy of fish oil supplements. Zinc supplementation has not been shown to be effective; however, some evidence is available (albeit conflicting) for vitamin D, vitamin B12, and selenium supplementation. Overwhelming evidence supports the effectiveness of Dead Sea climatotherapy. Finally, mindfulness-based stress reduction can be helpful as adjuvant treatment of psoriasis. There are potential benefits to these modalities, but also potential side issues. Concerns with CAM include, but are not limited to, contamination of TCM products with heavy metals or corticosteroids, systemic toxicity or contact dermatitis from herbal supplements, and ultraviolet light-induced carcinomas from climatotherapy. Dermatologists should be aware of these benefits and side effects to allow for informed discussions with their patients.