Indigo naturalis upregulates claudin-1 expression in human keratinocytes and psoriatic lesions

Prinsepia utilis Royle polysaccharides promote skin barrier repair through the Claudin family

BACKGROUND

Plant polysaccharides have various biological activities. However, few studies have been conducted on the skin barrier of Prinsepia utilis Royle polysaccharide extract (PURP).

MATERIALS AND METHODS

The proportions of polysaccharides, monosaccharides and proteins were determined by extracting polysaccharides from fruit meal using water. The healing rate was measured by cell scratch assays. SDS-damaged reconstructed human epidermal models, an acetone-ether-induced mouse model and an IL-4-induced cellular inflammation model were used to detect the effects of polysaccharides on the phenotype, HA, TEWL, and TEER, with further characterizations performed using QRT-PCR, Western blotting, immunofluorescence (IF) assays.

RESULTS

PURP contained 35.73% polysaccharides and 11.1% proteins. PURP promoted cell migration and increased skin thickness in a reconstructed human epidermis model. The TEWL significantly decreased, and the HA content significantly increased. PURP significantly increased the TEER and decreased the permeability of the SDS-damaged reconstructed human epidermis model. Claudin-3, Claudin-4, and Claudin-5 were significantly upregulated. IF and Western blot analysis revealed that the Claudin-4 level significantly increased after treatment with PURP. Claudin-1, Claudin-3, Claudin-4, and Claudin-5 gene expression and IF and immunohistochemical staining were significantly increased in mice treated with acetone-ether. PURP promoted the expression of Claudin-1, Claudin-3, Claudin-4, and Claudin-5 after treatment with 100 ng/mL IL-4. PURP also downregulated the expression of NO, IL6, TNFα and NFκB in Raw 264.7 cells and in a mouse model.

CONCLUSION

We hypothesize that PURP may repair the skin barrier by promoting the expression of the claudin family and can assist in skin therapy.

Recent Advances in Phytochemical-Based Topical Applications for the Management of Eczema: A Review

Eczema (atopic dermatitis, AD) is a skin disease characterized by skin barrier dysfunction due to various factors, including genetics, immune system abnormalities, and environmental triggers. Application of emollients and topical drugs such as corticosteroids and calcineurin inhibitors form the mainstay of treatments for this challenging condition. This review aims to summarize the recent advances made in phytochemical-based topical applications to treat AD and the different carriers that are being used. In this review, the clinical efficacy of several plant extracts and bioactive phytochemical compounds in treating AD are discussed. The anti-atopic effects of the herbs are evident through improvements in the Scoring Atopic Dermatitis (SCORAD) index, reduced epidermal thickness, decreased transepidermal water loss, and alleviated itching and dryness in individuals affected by AD as well as in AD mouse models. Histopathological studies and serum analyses conducted in AD mouse models demonstrated a reduction in key inflammatory factors, including thymic stromal lymphopoietin (TSLP), serum immunoglobulin E (IgE), and interleukins (IL). Additionally, there was an observed upregulation of the filaggrin (FLG) gene, which regulates the proteins constituting the stratum corneum, the outermost layer of the epidermis. Carriers play a crucial role in topical drug applications, influencing dose delivery, retention, and bioavailability. This discussion delves into the efficacy of various nanocarriers, including liposomes, ethosomes, nanoemulsions, micelles, nanocrystals, solid-lipid nanoparticles, and polymeric nanoparticles. Consequently, the potential long-term side effects such as atrophy, eruptions, lymphoma, pain, and allergic reactions that are associated with current topical treatments, including emollients, topical corticosteroids, topical calcineurin inhibitors, and crisaborole, can potentially be mitigated through the use of phytochemical-based natural topical treatments.

Theoretical characterization and biological activity investigation of indirubins, cyclin dependent kinases inhibitors

Up to now, significant research efforts have been directed towards investigating indirubin and its derivatives as potential candidates for developing new compounds with multiple biological activities. In the present work, natural indirubin and numerous of its chemical derivatives referred to as indirubins have been investigated computationally using DFT method with the B3LYP/6-311 + G(d,p) level of theory, in order to reveal structure- biological activity relationship. We started with a structural properties description. Results analysis indicated that extra interaction sites were provided through the set of substitutions in compounds (1): Indirubin-3'-monoxime, (2): Indirubin-5-sulfonic acid, (3): 5-Nitro-indirubinoxime, (4): 5'-OH-5-nitro-indirubinoxime (AGM130), (5): 7-Bromo-5'-carboxyindirubin-3'-oxime, and (6): 7 BIO and consequently, extra hydrogen bonds may be formed with the active sites of molecular targets, such as GSK-3, CDKs, and Aurora kinases, as well as the aryl hydrocarbon receptor. Subsequently, to get more information on the electronic properties of indirubin and its analogues, HOMO, LUMO, Egap, and further electronic parameters were carried out. The indirubin derivatives showed an easier interaction with its environment than indirubin, the parent compound. The UV-Visible spectra of indirubin and compounds 1-6 were also produced using TD-DFT with B3LYP functional and 6-311 + G(2d,p) basis set. The relationship between absorption and chemical structure is discussed. Two phototoxic brominated compounds showed important absorption spectra modifications. It was also found that the main absorption bands of all compounds derived from π→π*(HOMO→LUMO) transitions.Communicated by Ramaswamy H. Sarma.

Indirubin protects chondrocytes and alleviates OA by inhibiting the MAPK and NF-κB pathways

PHARMACOLOGICAL RELEVANCE

Indirubin (IR) is a key active ingredient in the traditional Chinese medication QingDai, also called indigo naturalis, which are extensively used in China to treat chronic diseases, such as inflammation and cancer. However, the function of IR in reducing chondrocyte inflammation in osteoarthritis (OA) is still unclear.

AIM OF THE STUDY

The aim of this research was to examine how IR inhibits arthritis and to highlight some of its cellular-level processes.

MATERIALS AND METHODS

Chondrocytes from the knee joint of C57 mice were gathered and grown for in vitro tests and used to determine the toxicity of IR toward chondrocytes using a CCK8 kit. Chondrocytes were treated with IL-1β and IR or with IL-1β alone, and western blotting was used to determine the expression levels of inflammatory mediators. Meanwhile, through the identification and examination of pertinent markers via quantitative PCR. By using PCR assays, western blotting, toluidine blue staining and safranin O staining, the expression of proteoglycan (AGG) and type II collagen (collagen II) was investigated. Furthermore, western blotting was used to detect activation of the NF-κB and MAPK signaling pathways, and immunofluorescence was used to detect p65 nuclear translocation. In an in vivo experiment, C57BL/6 mice were subjected to destabilization of the medial meniscus (DMM) surgery to produce an OA model, and IR was injected into the articular cavity for 8 weeks. Eventually, the mice were killed, and samples of the knee joints were obtained for histological examination and analysis.

RESULTS

IR significantly reduced the expression of inflammatory regulators in chondrocytes treated with IL-1β, including iNOS and COX-2. Inhibition of IL-1β induced production of the key catabolic enzymes MMP3, MMP13 and A5. Additionally, an improvement in the downregulation of collagen II and AGG expression was observed. Moreover, IR prevented the aberrant IL-1β-induced activation of the NF-κB and MAPK signaling pathways, which resulted in downregulation of p65 and p38 expression. Compared to the DMM group, the severity of cartilage injury in animals was dramatically lessened and OARSI scores were lower in the treated groups.

CONCLUSION

According to the above findings, IR is quite effective in preventing arthritis both in vivo and in vitro, suggesting that IR may be employed as a possible anti-arthritis drug.

Psoriasis treatment using Indigo Naturalis: Progress and strategy

ETHNOPHARMACOLOGICAL RELEVANCE

In recent years, there are increasing that the number of patients with psoriasis day by day, and it has become a common disease endangering public health. However, there is no specific cure for psoriasis or control of recurrence. Therefore, it's necessity to seek alternative and efficient therapy, such as Traditional Chinese Medicine (TCM). As a TCM and effective medicine for the treatment of psoriasis, Indigo Naturalis (Baphicacanthus Cusia (Nees) Bremek.) has the effect of clearing heat, detoxifying blood, eliminating spots, reducing fire and calming panic, and it is used in many classical prescriptions for the treatment of psoriasis.

AIM OF REVIEW

To review the latest progress and strategies of Indigo Naturalis in the treatment of psoriasis. This manuscript mainly clarifies the traditional medicinal applications, the mechanism of action and application strategies of Indigo Naturalis, and its preparations in the treatment of psoriasis.

MATERIALS AND METHODS

Detailed information on Indigo Naturalis was collected from various online databases (PubMed, GeenMedical, Web of Science, Google Scholar, China National Knowledge Infrastructure Database, and National Intellectual Property Administration).

RESULTS

This manuscript reviews a great deal of information about how Indigo Naturalis can treat psoriasis through immune cells, signal pathways and disease-related mediators. The mechanism of cymbididae is expounded from the aspects of regulating keratinocyte proliferation and differentiation, regulating inflammatory infiltration of cellular immune system and improving microvascular dilation and hyperplasia in skin lesions.

CONCLUSION

The action mechanisms of Indigo Naturalis on psoriasis reflect the characteristics of multiple components, multiple targets, and multiple pathways of Traditional Chinese medicine. However, some pharmacological and clinical research methods are improper, so that the results are difficult to explain at present. Therefore, further in-depth research is needed to provide knowledge in a wider range of areas to confirm the great therapeutic potential of Indigo Naturalis.

Psoriasis Patients with Specific HLA-Cw Alleles and Lower Plasma IL-17 Level Show Improved Response to Topical Lindioil Treatment

Purpose

Lindioil, a medicine refined from indigo naturalis (a herb used in Chinese medicine), is effective in treating severe psoriasis; however, responses vary across individual patients. We aim to investigate genetic predispositions associated with treatment response to topical Lindioil among patients with psoriasis and correlations with plasma cytokine patterns.

Patients and Methods

We enrolled 72 psoriasis patients treated with Lindioil ointment and analyzed the human leukocyte antigen class C (HLA-Cw) genotypes and plasma cytokine expression patterns. We developed regression models of treatment response, defined as Psoriasis Area and Severity Index (PASI) 75, to examine correlations among HLA-Cw alleles, cytokine levels, and treatment response to Lindioil.

Results

Patients harboring HLA-Cw*06:02 were significantly more likely to respond to Lindioil (P = 0.02, odds ratio [OR]: 6.88), whereas Lindoil was ineffective in those harboring HLA-Cw*01:02 (P = 0.01, OR: 0.28). Patients who were HLA-Cw*06:02-positive or HLA-Cw*01:02-negative had better PASI scores and body surface area (BSA) improvement (73.3% vs 44.4%, P<0.001) following an 8-week treatment period. Psoriasis patients achieving PASI 75 after 8 weeks presented with lower baseline plasma interleukin-17 (IL-17) levels than those who did not achieve PASI 75 (PASI 75: 11.28 pg/mL vs PASI <75: 15.82 pg/mL, P = 0.05).

Conclusion

Our findings suggest that the presence of the HLA-Cw*06:02 or HLA-Cw*01:02 alleles and plasma IL-17 levels are predictive markers of treatment response to Lindioil ointment in patients with psoriasis.

Intervention Mechanism of Hunag-Lian Jie-Du Decoction on Canonical Wnt/β-Catenin Signaling Pathway in Psoriasis Mouse Model

Background

Psoriasis is a common chronic inflammatory skin disease with multifactor etiology, characterized by abnormal proliferation and differentiation of keratinocytes. Huang-Lian Jie-Du decoction (HLJDD) is a traditional Chinese medicine prescription with good clinical curative effect on psoriasis. However, its therapeutic mechanisms are still unclear.

Methods

The psoriasis model of SKH-1 nude mice was established by imiquimod-induced and HLJDD gavage was given. Hematoxylin and eosin staining were used to evaluate pathological morphologies, and immunohistochemistry was used to detect the expressions of Wnt1, β-catenin, and c-Myc in psoriasis mice. Western blot was used to examine the expressions of Frizzled-2, LRP5/6, GSK-3β, APC, Axin2, TCF4, LEF1, cyclin D1, TBX3, EPHB2, and NOTUM enzyme.

Results

In this study, HLJDD reduced skin erythema and lesions, decreased the thickness of epidermal and downregulated the expressions of Wnt1, β-catenin, and c-Myc. Western blot results showed that HLJDD reduced the expressions of Wnt receptors Frizzled-2 and LRP5/6, and Wnt downstream target genes TCF4, LEF1, cyclin D1, TBX3, and EPHB2, while upregulated destruction complex proteins GSK-3β, APC, and Axin2.

Conclusions

HLJDD can effectively treat psoriasis and inhibit the Wnt/β-catenin signaling pathway at multiple stages.

Evaluation of Serum Proinflammatory Cytokine IL-17A and Tight Junction Protein Claudin-1 in Psoriasis

Objective

This study aimed to estimate serum IL-17A and Claudin-1 levels, investigate their correlation, and evaluate their diagnostic significance as potential blood-based biomarkers in psoriasis.

Methods

Serum IL-17A and Claudin-1 concentrations were determined using enzyme-linked immunosorbent assay (ELISA). Statistical analyses were performed to determine differences in serum levels of IL-17A and Claudin-1, their bivariable correlation with psoriasis severity, as Psoriasis Area Severity Index (PASI), and their predictive abilities using receiver operating characteristic (ROC) curves.

Results

Significantly higher IL-17A and lower Claudin-1 levels were found in psoriasis (p < 0.05). PASI did not correlate significantly with either IL-17A or Claudin-1 in psoriasis and their subtypes. The only significant correlation between serum IL-17A and Claudin-1 was shown in late-onset psoriasis (r = 0.630, p = 0.028). ROC curve analysis indicated the serum IL-17A, serum Claudin-1, and combination of IL-17A and serum Claudin-1 for predicting psoriasis with the areas under the curve (AUC) of 0.951 (p < 0.0001), 0.709 (p = 0.0119), and 0.949 (p < 0.0001), respectively. Moreover, the potential role in distinguishing between early-onset and late-onset psoriasis: we obtained serum IL-17A, serum Claudin-1, and their combination AUC of 0.590 (p = 0.3126), 0.741 (p = 0.0045), and 0.741 (p = 0.0067), respectively. However, none of the serum IL-17A, serum Claudin-1, and their combination was well-performed discriminating mild psoriasis from moderate-to-severe psoriasis with AUC of 0.553 (p = 0.5596), 0.518 (p = 0.8539), and 0.559 (p = 0.5225), respectively.

Conclusion

These preliminary results suggest that the serum Claudin-1 as a potential biomarker and the relationship and possible regulatory interactions between IL-17A and Claudin-1 in psoriasis are distinguishable by age of onset.

Nutrition and nail disease

The nail is a specialized keratinous skin appendage that is often overlooked, even though nail disorders comprise approximately 10% of all dermatologic conditions. We provide an overview on the basic anatomy of the nail and function of each structure. We examine the chemical profile, including the keratin and mineral composition, of the nail plate. Subsequently, nail manifestations are reviewed, as virtually every nutritional deficiency can affect nail growth in some manner. We focus on how each nutritional deficiency can affect the different anatomic structures of the nail unit. The terminology and the differential diagnoses of the many different nail plate and nail bed abnormalities are reviewed. Finally, we focus on the evidence behind nutrition-based treatments in the setting of several nail disorders.

Role of AHR Ligands in Skin Homeostasis and Cutaneous Inflammation

Aryl hydrocarbon receptor (AHR) is an important regulator of skin barrier function. It also controls immune-mediated skin responses. The AHR modulates various physiological functions by acting as a sensor that mediates environment–cell interactions, particularly during immune and inflammatory responses. Diverse experimental systems have been used to assess the AHR’s role in skin inflammation, including in vitro assays of keratinocyte stimulation and murine models of psoriasis and atopic dermatitis. Similar approaches have addressed the role of AHR ligands, e.g., TCDD, FICZ, and microbiota-derived metabolites, in skin homeostasis and pathology. Tapinarof is a novel AHR-modulating agent that inhibits skin inflammation and enhances skin barrier function. The topical application of tapinarof is being evaluated in clinical trials to treat psoriasis and atopic dermatitis. In the present review, we summarize the effects of natural and synthetic AHR ligands in keratinocytes and inflammatory cells, and their relevance in normal skin homeostasis and cutaneous inflammatory diseases.

A Comprehensive Review of the Chemistry, Pharmacokinetics, Pharmacology, Clinical Applications, Adverse Events, and Quality Control of Indigo Naturalis

Indigo naturalis (IN), which is derived from indigo plants such as Strobilanthes cusia (Nees) Kuntze, Persicaria tinctoria (Aiton) Spach, and Isatis tinctoria L., has been traditionally used in the treatment of hemoptysis, epistaxis, chest pain, aphtha, and infantile convulsion in China for thousands of years. Clinical trials have shown that the curative effect of IN for psoriasis and ulcerative colitis (UC) is remarkable. A total of sixty-three compounds, including indole alkaloids, terpenoids, organic acids, steroids, and nucleosides, have been isolated from IN, of which indole alkaloids are the most important. Indirubin, isolated from IN, was used as a new agent to treat leukemia in China in the 1970s. Indirubin is also an active ingredient in the treatment of psoriasis. Pharmacological studies have confirmed that IN has inhibitory effects on inflammation, tumors, bacteria, and psoriasis. Indigo, indirubin, tryptanthrin, isorhamnetin, indigodole A, and indigodole C are responsible for these activities. This review provides up-to-date and comprehensive information on IN with regard to its chemistry, pharmacokinetics, pharmacology, clinical applications, adverse events, and quality control. This review may also serve a reference for further research on IN.

Indirubin attenuates IL-17A-induced CCL20 expression and production in keratinocytes through repressing TAK1 signaling pathway

Psoriatic skin inflammation is mainly driven by complex interactions of infiltrating immune cells and activated keratinocytes. Keratinocytes play an active role in initiating and maintenance of psoriatic skin inflammation by secreting chemokines and cytokines. IL-17A produced by T cells potently upregulates the production of chemokine CCL20 in the keratinocytes, which further chemoattracts IL-17A-producing CCR6+ immune cells to the site of inflammation. Indirubin, an active constituent of indigo naturalis, has been reported to possess anti-inflammatory activities, but whether it can suppress the production of chemokines in keratinocytes is largely unknown. To address this question, IL-17A stimulated HaCaT cells were used as cell model to explore the effects of indirubin on the expression and secretion of chemokines. Also, RNA-seq analysis was performed to extensively understand the entire gene expression changes after indirubin treatment and identify the differentially expressed genes further. Indirubin treatment strongly inhibited CCL20 expression and secretion in IL-17A stimulated HaCaT cells. The inhibitory action of indirubin on CCL20 expression was mainly mediated by TAK1 signaling pathway in a mouse psoriasis-like model and cultured HaCaT cells in vitro. Combining with our previous report, indirubin ameliorated psoriasiform dermatitis by breaking CCL20/CCR6 axis-mediated inflammatory loops. Our results provide novel insights into the mechanisms of indirubin in the treatment of psoriasis.

Strobilanthes cusia (Nees) Kuntze, a multifunctional traditional Chinese medicinal plant, and its herbal medicines: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Strobilanthes cusia (Nees) Kuntze (SCK, Malan), a traditional Chinese medicinal plant, has long applied to detoxification, defervescence, detumescence and antiphlogosis. "Southern Banlangen" (Rhizoma et Radix Baphicacanthis Cusiae, RRBC), root and rhizome of SCK, is widely used for treatment of many epidemic diseases. Malanye (Southern Daqingye), stem and leaf of SCK, is an antipyretic-alexipharmic drug frequently-used in southern China. Qingdai (Indigo Naturalis, IN), a processed product of SCK, is always applied to dermatoses in the folk.

AIM OF THE REVIEW

In order to elucidate the historical uses, recent advances and pharmaceutical prospects of SCK, we summarized roundly in aspects of history, processing method, chemical constitution, quality control, pharmacological activity and toxicity. Some deficiencies in current studies and research directions in the future are also discussed. This is the first comprehensive review of SCK and its herbal medicines, which may be of some help for further research.

METHODOLOGY

Comprehensive analysis was conducted on the basis of academic papers, pharmaceutical monographs, ancient medicinal works, and drug standards of China. All available information on SCK and its herbal medicines was collected by using the keywords such as "Strobilanthes cusia", "Southern Banlangen", "indirubin", "tryptanthrin" through different electronic databases including NCBI Pubmed, Google Scholar, Chinese National Knowledge Infrastructure and so on. Pharmacopoeia of China and some ancient works were obtained from National Digital Library of China.

RESULT

Medicinal uses of SCK were already described by famous ancient researchers. Because of vague description, plant species in some works cannot be confirmed. Literature demonstrated that multiple components including total 36 alkaloids and 35 glycosides, the main bioactive components of SCK, were found in SCK and its herbal medicines. Modern studies indicated that SCK and some of its components had multiple pharmacological effects including resistance to cancer, remission of inflammation, suppression of microorganisms, relief of dermatoses, and so on. However, studies on pharmacology, pharmacokinetics, and quality control are still not enough.

CONCLUSION

A number of reports suggested that SCK and its processed medicines could be promising drug candidates for multiple diseases especially promyelocytic leukemia, ulcerative colitis (UC) and psoriasis. However, bioactive activities of most components, especially glycosides should still be explored further. It is crucial to elucidate the in-depth molecular mechanisms, and pharmacokinetic characteristics of main components in those herbal medicines. Moreover, to ensure the effectiveness of clinical medication, future studies should undoubtedly give the priority to clarifying the effective compositions of SCK, and then a measurement standard of those indicators should be protocolled to establish a comprehensive quality evaluation mode.

Efficacy and safety of indigo naturalis ointment in Treating Atopic Dermatitis: A randomized clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Indigo naturalis, a herbal medicine with a history of use dating back to ancient times, may be a good alternative topical treatment for atopic dermatitis (AD).

AIM OF THE STUDY

To provide empirical evidence of the efficacy and safety of Indigo naturalis ointment in treating AD.

MATERIALS AND METHODS

In this randomized double-blind clinical trial, participants aged 6 to 65 years with AD affecting less than 40% of their body surface area (BSA) and an Investigator's Global Assessment (IGA) score of 2 to 4 were randomized (2:1) to receive either Lindioil ointment or a vehicle ointment twice daily for 6 weeks. The primary endpoint was the percentage change in the Eczema Area Severity Index (EASI) from baseline to week 6. Secondary endpoints were as follows: EASI improvement ≥50%, 75%, and 90%; IGA score; BSA affected by AD; pruritus severity; and Dermatology Life Quality Index. The safety assessment included adverse events (AEs), laboratory tests, and physical examinations.

RESULTS

The Lindioil group (32 participants) and vehicle group (16 participants) achieved mean percentage EASI reductions of 49.9% ± 36.5% (95% CI 36.8%-63.1%) and 19.6% ± 52.2% (95% CI -8.2%-47.4%), respectively (P = 0.0235). The Lindioil group also showed greater improvement in every secondary assessment category. No significant AEs occurred.

CONCLUSION

Indigo naturalis ointment is effective for treating mild to severe AD topically, and appears to be safe. This is the first clinical trial to provide evidence supporting topical indigo-based AD treatment. ClinicalTrials.gov identifier: NCT02669888.

Chrysin alleviates imiquimod-induced psoriasis-like skin inflammation and reduces the release of CCL20 and antimicrobial peptides

Psoriasis is a common non-contagious chronic inflammatory skin lesion, with frequent recurrence. It mainly occurs due to aberrant regulation of the immune system leading to abnormal proliferation of skin cells. However, the pathogenic mechanisms of psoriasis are not fully understood. Although most of the current therapies are mostly efficient, the side effects can result in therapy stop, which makes the effectiveness of treatment strategies limited. Therefore, it is urgent and necessary to develop novel therapeutics. Here, we investigated the efficacy of chrysin, a plant flavonoid, which we previously reported to possess strong antioxidant and anti-inflammatory effects, against psoriasis-like inflammation. Our results revealed that chrysin significantly attenuated imiquimod-induced psoriasis-like skin lesions in mice, and improved imiquimod-induced disruption of skin barrier. Moreover, the TNF-α, IL-17A, and IL-22-induced phosphorylation of MAPK and JAK-STAT pathways, and activation of the NF-κB pathway were also attenuated by chrysin pretreatment of epidermal keratinocytes. Most importantly, chrysin reduced TNF-α-, IL-17A-, and IL-22-induced CCL20 and antimicrobial peptide release from epidermal keratinocytes. Thus, our findings indicate that chrysin may have therapeutic potential against inflammatory skin diseases. Our study provides a basis for further investigating chrysin as a novel pharmacologic agent and contributes to the academic advancement in the field of Chinese herbal medicine.

Indigo Naturalis Suppresses Colonic Oxidative Stress and Th1/Th17 Responses of DSS-Induced Colitis in Mice

Indigo naturalis (also known as Qing-dai, or QD), a traditional Chinese medicine, has been widely used as an anticolitis regimen in the clinical practice of Chinese medicine. However, the precise mechanisms behind its efficacy remain unknown. We investigated the protective effects and associated molecular mechanisms of QD in DSS-induced colitis in mice. We found that QD administration attenuated DSS-induced colon shortening, tissue damage, and the disease activity index during the onset of colitis. Moreover, QD administration significantly suppressed colonic MPO activity and increased the activities of colonic T-SOD, CAT, and GSH-Px, as well the expression of p-AMPK and Nrf-2 in colon tissues of colitic mice. In addition, QD was capable of reducing the colonic Th1 and Th17 cell cytokines, the frequencies of Th1 and Th17 cells, and the phosphorylation of p-STAT1 and p-STAT3 in the mesenteric lymph nodes of colitic mice. An in vitro assay showed that QD significantly suppressed the differentiation of Th1 and Th17 cells. These findings suggest that QD has the potential to alleviate experimental colitis by suppressing colonic oxidative stress and restraining colonic Th1/Th17 responses, which are associated with activating AMPK/Nrf-2 signals and inhibiting STAT1/STAT3 signals, respectively. These findings also support QD as an effective regimen in the treatment of IBD.

Activation of the Ca2+ sensing receptor and the PKC/WNK4 downstream signaling cascade induces incorporation of ZO-2 to tight junctions and its separation from 14-3-3

Zonula occludens-2 (ZO-2) is a tight junction (TJ) cytoplasmic protein, whose localization varies according to cell density and Ca²⁺ in the media. In cells cultured in low calcium (LC), ZO-2 displays a diffuse cytoplasmic distribution, but activation of the Ca²⁺ sensing receptor (CaSR) with Gd³⁺ triggers the appearance of ZO-2 at the cell borders. CaSR downstream signaling involves activation of protein kinase C, which phosphorylates and activates with no lysine kinase-4 that phosphorylates ZO-2 inducing its concentration at TJs. In LC, ZO-2 is protected from degradation by association to 14-3-3 proteins. When monolayers are transferred to normal calcium, the complexes ZO-2/14-3-3ζ and ZO-2/14-3-3σ move to the cell borders and dissociate. The 14-3-3 proteins are then degraded in proteosomes, whereas ZO-2 integrates to TJs. From the plasma membrane residual ZO-2 is endocyted and degradaded in lysosomes. The unique region 2 of ZO-2, and S261 located within a nuclear localization signal, are critical for the interaction with 14-3-3 ζ and σ and for the efficient nuclear importation of ZO-2. These results explain the molecular mechanism through which extracellular Ca²⁺ triggers the appearance of ZO-2 at TJs in epithelial cells and reveal the novel interaction between ZO-2 and 14-3-3 proteins, which is critical for ZO-2 protection and intracellular traffic.

Low-dose action of tryptanthrin and its derivatives against developing embryos of the sea urchin Strongylocentrotus intermedius

Nine tryptanthrin derivatives, including tryptanthrin itself, were synthesized using different methods, including oxidation of the corresponding isatins to obtain 1-4, the reaction of tryptanthrin 1 with hydrazine and its derivatives to obtain 5-7, and aldol condensation of 1 with acetone and methylethylketone to obtain 8 and 9. The action of 1-9 in doses corresponding to the IC₅₀ against developing embryos of the sea urchin Strongylocentrotus intermedius and in the sperm test allowed us to estimate to potency of all the compounds and to determine which were cytotoxic. In addition, these studies showed that compounds 3, 4, 8, and 9 had a stimulatory effect at lower doses. In particular, the tryptanthrin derivatives stimulated the larval stages of development in surviving embryos at concentrations lower than the IC₅₀.

Indirubin ameliorates imiquimod-induced psoriasis-like skin lesions in mice by inhibiting inflammatory responses mediated by IL-17A-producing γδ T cells

OBJECTIVES

Indirubin (IR) is a bisindole compound extracted from the leaves of Chinese herb Indigo Naturalis. Indigo Naturalis has been widely used in traditional Chinese medicine to treat inflammatory and autoimmune diseases. Psoriasis is a chronic immune-mediated inflammatory skin disease in which γδ T cells play an important role. This study aims to determine the immunoregulatory effects and the underlying mechanisms of Indirubin in psoriasis-related inflammatory responses.

METHODS

BALB/c mice with imiquimod (IMQ)-induced psoriasis-like dermatitis were treated with saline (Model), 1 mg/kg methotrexate (MTX) that serves as a positive control, or 12.5, 25 and 50 mg/kg Indirubin(IR) intragastrically. Keratinocytes proliferation, inflammatory cells infiltration, the expression of inflammatory cytokines and Jak/Stat pathway-related proteins in the skin lesion were examined. The abundance of γδ T cells in lymph nodes and spleen was determined by flow cytometry. The IL-17 expression and secretion, and the activation of Jak3/Stat3 pathways in in vitro cultured γδ T cell were tested.

RESULTS

Indirubin ameliorated keratinocyte proliferation, reduced the infiltration of CD3⁺ T cells, IL-17 A-producing γδ T cells, and CD11b⁺ neutrophils, inhibited the mRNA expression of Il1, Il6, Il23, Il17a and Il22, and the protein expression of Jak/Stat pathway-related molecules in the skin lesion. Indirubin also reduced the abundance of γδ T cell and CCR6⁺ γδ T cells (the major IL-17 A producer) in spleen and lymph nodes. In cultured γδ T cells, Indirubin inhibited the mRNA expression of Il17a and Ifng, and the secretion of IL-17 A, while suppressed the activation of Jak3/Stat3 pathways.

CONCLUSION

Indirubin alleviates IMQ-induced psoriasis-like dermatitis mainly through reducing the inflammatory responses mediated by IL-17 A-producing γδ T cells involving Jak3/Stat3 activation. Our results highlighted the novel mechanisms by which Indirubin ameliorates psoriasis-related inflammatory responses, supporting its therapeutic potential.

The Therapeutic Potential and Molecular Mechanism of Isoflavone Extract against Psoriasis

Psoriasis is a common inflammatory disease. It affects 1-3% of the population worldwide and is associated with increasing medical costs every year. Typical psoriatic skin lesions are reddish, thick, scaly plaques that can occur on multiple skin sites all over the body. Topical application of imiquimod (IMQ), a toll-like receptor (TLR)7 agonist and potent immune system activator, can induce and exacerbate psoriasis. Previous studies have demonstrated that isoflavone extract has an antioxidant effect which may help decrease inflammation and inflammatory pain. Through in vivo studies in mice, we found that the topical application to the shaved back and right ear of mice of isoflavone extract prior to IMQ treatment significantly decreased trans-epidermal water loss (TEWL), erythema, blood flow speed, and ear thickness, while it increased surface skin hydration, and attenuated epidermal hyperplasia and inflammatory cell infiltration. Through in vitro experiments, we found that isoflavone extract can reduce IL-22, IL-17A, and TNF-α-induced MAPK, NF-κB, and JAK-STAT activation in normal human epidermal keratinocytes. At the mRNA level, we determined that isoflavone extract attenuated the increased response of the TNF-α-, IL-17A-, and IL-22- related pathways. These results indicate that isoflavone extract has great potential as an anti-psoriatic agent and in the treatment of other inflammatory skin diseases.

Indigo Naturalis Ameliorates Oxazolone-Induced Dermatitis but Aggravates Colitis by Changing the Composition of Gut Microflora

BACKGROUND

Indigo naturalis (IND) is an herbal medicine that has been used as an anti-inflammatory agent to treat diseases including dermatitis and inflammatory bowel disease in China. However, the mechanism by which IND exerts its immunomodulatory effect is not well understood.

METHODS

A murine model of dermatitis and inflammatory bowel disease, both induced by oxazolone (OXA), was treated with IND. The severity of dermatitis was evaluated based on ear thickness measurements and histological scoring. The severity of colitis was evaluated by measuring body weight, histological scoring, and endoscopic scoring. The expression of inflammatory cytokines in ear and colon tissue was evaluated using real-time PCR. 16S rRNA DNA sequencing of feces from OXA-induced colitis mice was performed before and after IND treatment. The effects of IND on OXA-induced colitis were also evaluated after depleting the gut flora with antibiotics to test whether alteration of the gut flora by IND influenced the course of intestinal inflammation in this model.

RESULTS

IND treatment ameliorated OXA dermatitis with a reduction in IL-4 and eosinophil recruitment. However, OXA colitis was significantly aggravated in spite of a reduction in intestinal IL-13, a pivotal cytokine in the induction of the colitis. It was found that IND dramatically altered the gut flora and IND no longer exacerbated colitis when colitis was induced after gut flora depletion.

CONCLUSIONS

Our data suggest that IND could modify the inflammatory immune response in multiple ways, either directly (i.e., modification of the allergic immune cell activity) or indirectly (i.e., alteration of commensal compositions).

Indigo naturalis and its component tryptanthrin exert anti-angiogenic effect by arresting cell cycle and inhibiting Akt and FAK signaling in human vascular endothelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Indigo naturalis has been used to treat inflammatory diseases and dermatosis, including psoriasis, since thousands of years in China. It has been proven effective in our previous clinical studies on treating psoriasis, but the active component and the mechanism of how indigo naturalis working still needs to be clarified. Since the dysregulated angiogenesis is known to play an important role in the pathogenesis of psoriasis, the anti-angiogenic effect of indigo naturalis and tryptanthrin, a pure component of indigo naturalis, was investigated.

MATERIALS AND METHODS

The in vivo angiogenesis was studied by chick chorioallantoic membrane assay. The in vitro studies were performed using human vascular endothelial cells. Cell viability was determined by MTT assay. Cell cycle distribution was revealed by flow cytometry. The cellular messenger (m)RNA or protein expression level was analyzed by real-time RT-PCR or Western blot, respectively. Transwell filter migration assay and matrix gel-induced tube formation method were applied to examine the angiogenic potential.

RESULTS

Indigo naturalis significantly inhibited the in vivo vascular endothelial growth factor (VEGF)-induced angiogenesis, as well as tryptanthrin. In vitro studies confirmed that indigo naturalis and tryptanthrin reduced the number of viable vascular endothelial cells. Tryptanthrin resulted in a cell cycle arrest and dose-dependently decreased the expressions of cyclin A, cyclin B, cyclin dependent kinase(CDK) 1 and 2, but not cyclin D and cyclin E, at both the mRNA and protein levels. The migration and tube formation of vascular endothelial cells were significantly inhibited by tryptanthrin in a dose-dependent manner. Result also showed that tryptanthrin could reduce the phosphorylated levels of both protein kinase B (PKB or Akt) and focal adhesion kinase (FAK).

CONCLUSIONS

All together, these results demonstrated the anti-angiogenic effect of tryptanthrin, the acting component of indigo naturalis and revealed the underlying mechanism by inhibiting the cell cycle progression, cell migration and tube formation, likely mediated through blocking the Akt and FAK pathways.

Indirubin and Indirubin Derivatives for Counteracting Proliferative Diseases

Indirubin is the active component of Danggui Longhui Wan, a traditional Chinese medicine formulation. The encouraging clinical results from the 1980s obtained in chronic myelocytic leukemia patients treated with indirubin stimulated numerous studies on this compound. These investigations explored the use of indirubin in different types of cancer and reported the synthesis of novel derivatives with improved chemical and pharmacokinetic properties. In this paper, we review the impressive progress that has been made in elucidating the mechanistic understanding of how indirubin and its derivatives affect physiological and pathophysiological processes, mainly by inhibition of cell proliferation and induction of cell death. Furthermore, we survey the therapeutic use of these compounds in combating proliferative diseases such as cancer, restenosis, and psoriasis.

PKCδ-iPLA2-PGE2-PPARγ signaling cascade mediates TNF-α induced Claudin 1 expression in human lung carcinoma cells

Claudin 1 (CLDN1) is a critical component of tight junction adhesion complexes that maintains the structural integrity of epithelial cell layers. Dysregulation of CLDN1 is associated with the growth and metastasis of human lung adenocarcinoma. TNF-α treatment was previously shown to increase expression of CLDN1 that mediated lung cancer cell morphology changes and migration. This study aimed to elucidate the molecular mechanisms involved in TNF-α induced CLDN1 expression in human lung carcinoma A549 cells. Chemical inhibition or siRNA downregulation of Src, PI3K, Akt, MAPKs, NFκB, caspase and PKC demonstrated that PKC, specifically PKCδ, is required for TNF-α induced CLDN1 expression. Further investigation of the PKC pathway revealed that CLDN1 expression is enhanced by the downstream molecules iPLA2, PGE2, 15-keto PGE2 and PPARγ. Conversely, inhibition of these molecules decreased CLDN1 expression. Additionally, a wound-healing assay demonstrated that TNF-α stimulation, PKC activation, prostaglandin treatment or PPARγ activation enhanced cell migration. In conclusion, TNF-α induced CLDN1 expression is regulated by the PKCδ-iPLA2-PGE2-PPARγ signaling cascade in human lung carcinoma A549 cells.

Efficacy and safety of Indigo naturalis extract in oil (Lindioil) in treating nail psoriasis: a randomized, observer-blind, vehicle-controlled trial

Treating nail psoriasis is notoriously difficult and lacks standardized therapeutic regimens. Indigo naturalis has been demonstrated to be safe and effective in treating skin psoriasis. This trial was conducted to evaluate the efficacy and safety of refined indigo naturalis extract in oil (Lindioil) in treating nail psoriasis. Thirty-one outpatients with symmetrically comparable psoriatic nails were enrolled. Lindioil (experimental group) or olive oil (control group) was applied topically to the same subjects' two bilaterally symmetrical psoriatic nails twice daily for the first 12 weeks and then subjects applied Lindioil to both hands for 12 additional weeks. Outcomes were measured using Nail Psoriasis Severity Index (NAPSI) for five nails on one hand and for the single most severely affected nail from either hand. The results show a reduction of NAPSI scores for the 12-week treatment for the Lindioil group (49.8% for one hand and 59.3% for single nail) was superior to the reduction in the scores for the control group (22.9%, 16.3%, respectively). There were no adverse events during the 24 weeks of treatment. This trial demonstrates that Lindioil is a novel, safe and effective therapy for treating nail psoriasis.

An in vitro study of the antimicrobial effects of indigo naturalis prepared from Strobilanthes formosanus Moore

Indigo naturalis is effective in treating nail psoriasis coexisting with microorganism infections. This study examines the antimicrobial effects of indigo naturalis prepared from Strobilanthes formosanus Moore. Eight bacterial and seven fungal strains were assayed using the agar diffusion method to examine the effects of indigo naturalis and its bioactive compounds. The bioactive compounds of indigo naturalis were purified sequentially using GFC, TLC, and HPLC. Their structures were identified using mass spectrometry and NMR spectroscopy. UPLC-MS/MS was applied to compare the metabolome profiles of indigo naturalis ethyl-acetate (EA) extract and its source plant, Strobilanthes formosanus Moore. The results of in vitro antimicrobial assays showed that indigo naturalis EA-extract significantly (≥1 mg/disc) inhibits Gram-positive bacteria (Staphylococcus aureus, S. epidermis and methicillin-resistant S. aureus (MRSA)) and mildly inhibits non-dermatophytic onychomycosis pathogens (Aspergillus fumigates and Candida albicans), but has little effect on dermatophyes. Isatin and tryptanthrin were identified as the bioactive compounds of indigo naturalis using S. aureus and S. epidermis as the bioassay model. Both bioactive ingredients had no effect on all tested fungi. In summary, indigo naturalis prepared from Strobilanthesformosanus Moore exhibits antimicrobial effects on Staphylococcus and non-dermatophytic onychomycosis pathogens. Tryptanthrin and isatin may be its major bioactive ingredients against Staphylococcus and the inhibitory effect on MRSA may be due to other unidentified ingredients.