The natural plant product tryptanthrin ameliorates dextran sodium sulfate-induced colitis in mice

Visible-light promoted catalyst-free (VLCF) multi-component synthesis of spiro indolo-quinazolinone-pyrrolo[3,4-a]pyrrolizine hybrids: evaluation of in vitro anticancer activity, molecular docking, MD simulation and DFT studies

A new and highly efficient visible-light-promoted catalyst free (VLCF) strategy for neat and clean synthesis of spiro indolo-quinazolinone-pyrrolo[3,4-a]pyrrolizine hybrids (6a-d) has been introduced. We have performed visible-light triggered 1,3-Dipolar cycloaddition reaction of maleimide (5a-d) with azomethine ylide generated in situ derived from tryptanthrin (3) and L-proline (4) to obtain desired products (6a-d) in good to excellent yield. Authentication and characterization of product was done using various spectroscopic techniques such as IR, 1H NMR, 13C NMR, Mass spectrometry and single crystal XRD analysis. To explain the reaction spontaneity, product stability, reactivity as well as possible mode of the interaction a quantum chemical investigation was performed and depicted through DFT studies. The synthesized compound 6a was also evaluated for anti-proliferative activity against a panel of five cancer cell lines (MCF-7, MDA-MB-231, HeLa, PC-3 and Ishikawa) and normal human embryonic kidney (HEK-293) cell line by using MTT assay. Compound 6a showed very good in vitro anti-proliferative activity (IC50  = 6.58-17.98 μM) against four cancer cell lines and no cytotoxicity against normal HEK-293. In order to evaluate the anticancer potential of compounds 6a-d, molecular docking was performed against wild type and mutant EGFR. The results suggest that all the compounds occupied the active site of both enzymes, with a strong binding energy (-10.2 to -11.5 kcal/mol). These results have been confirmed by molecular dynamics simulation by evaluating root mean square deviation (RMSD) and root mean square fluctuation (RMSF), along with principal component analysis (PCA).Communicated by Ramaswamy H. Sarma.

The double-edged sword effect of indigo naturalis

Indigo naturalis (IN) is a dried powder derived from plants such as Baphicacanthus cusia (Neeks) Bremek., Polygonum tinctorium Ait. and Isatis indigotica Fork. It has a historical application as a dye in ancient India, Egypt, Africa and China. Over time, it has been introduced to China and Japan for treatment of various ailments including hemoptysis, epistaxis, chest discomfort, and aphtha. Clinical and pre-clinical studies have widely demonstrated its promising effects on autoimmune diseases like psoriasis and Ulcerative colitis (UC). Despite the documented efficacy of IN in UC patients, concerns have been raised on the development of adverse effects with long term consumption, prompting a closer examination of its safety and tolerability in these contexts. This review aims to comprehensively assess the efficacy of IN in both clinical and pre-clinical settings, with a detailed exploration of the mechanisms of action involved. Additionally, it summarizes the observed potential toxicity of IN in animal and human settings was summarized. This review will deepen our understanding on the beneficial and detrimental effects of IN in UC, providing valuable insights for its future application in patients with this condition.

Extraction, Purification, Structural Characteristics, Biological Activity and Application of Polysaccharides from Portulaca oleracea L. (Purslane): A Review

Portulaca oleracea L. (purslane) is a widely distributed plant with a long history of cultivation and consumption. Notably, polysaccharides obtained from purslane exhibit surprising and satisfactory biological activities, which explain the various benefits of purslane on human health, including anti-inflammatory, antidiabetic, antitumor, antifatigue, antiviral and immunomodulatory effects. This article systematically reviews the extraction and purification methods, chemical structure, chemical modification, biological activity and other aspects of polysaccharides from purslane collected in the Chinese Pharmacopoeia, Flora of China, Web of Science, PubMed, Baidu Scholar, Google Scholar and CNKI databases in the last 14 years, using the keywords "Portulaca oleracea L. polysaccharides" and "purslane polysaccharides". The application of purslane polysaccharides in different fields is also summarized, and its application prospects are also discussed. This paper provides an updated and deeper understanding of purslane polysaccharides, which will provide useful guidance for the further optimization of polysaccharide structures and the development of purslane polysaccharides as a novel functional material, as well as a theoretical basis for its further research and application in human health and manufacturing development.

Treatment with indigo plant (Polygonum tinctorium Lour) improves serum lipid profiles in Wistar rats fed a high-fat diet

We investigated the effects of Polygonum tinctorium Lour (PTL), a plant commonly known as indigo, on biological parameters in an animal model of high-fat diet-induced obesity. Wistar rats fed a high-fat diet and treated with PTL showed lower serum levels of triglycerides and total cholesterol levels and a higher serum levels of HDL cholesterol than those in Wistar rats fed a high-fat diet without PTL treatment. The weight of mesenteric fat in PTL-treated rats was decreased compared to that in control rats not treated with PTL. In addition, energy metabolic rate in the dark period, but not in the light period, in PTL-treated rats was higher than that in control rats. Although a significant difference was not observed, body weight in PTL-treated rats tended to be decreased compared to that in control rats. The results show that PTL improves serum lipid profiles in Wistar rats with high-fat diet-induced obesity. J. Med. Invest. 67 : 158-162, February, 2020.

Tryptanthrin exerts anti-breast cancer effects both in vitro and in vivo through modulating the inflammatory tumor microenvironment

Tryptanthrin is an indole quinazoline alkaloid from the indigo-bearing plants, such as Isatis indigotica Fort. Typically, this natural compound shows a variety of pharmacological activities such as antitumor, antibacterial, anti-inflammatory and antioxidant effects. This study was conducted to assess the antitumor activity of tryptanthrin in breast cancer models both in vitro and in vivo, and to explore the important role of the inflammatory tumor microenvironment (TME) in the antitumor effects of tryptanthrin. Human breast adenocarcinoma MCF-7 cells were used to assess the antitumor effect of tryptanthrin in vitro. MTT assay and colony formation assay were carried out to monitor the antiproliferative effect of tryptanthrin (1.56~50.0 μmol L-1) on inhibiting the proliferation and colony formation of MCF-7 cells, respectively. The migration and invasion of MCF-7 cells were evaluated by wound healing assay and Transwell chamber assay, respectively. Moreover, the 4T1 murine breast cancer model was established to examine the pharmacological activity of tryptanthrin, and three groups with different doses of tryptanthrin (25, 50 and 100 mg kg-1) were set in study. Additionally, tumor volumes and organ coefficients were measured and calculated. After two weeks of tryptanthrin treatment, samples from serum, tumor tissue and different organs from tumor-bearing mice were collected, and the enzyme-linked immunosorbent assay (ELISA) was performed to assess the regulation of inflammatory molecules in mouse serum. Additionally, pathological examinations of tumor tissues and organs from mice were evaluated through hematoxylin and eosin (H&E) staining. The expression of inflammatory proteins in tumor tissues was measured by immunohistochemistry (IHC) and Western blotting. Tryptanthrin inhibited the proliferation, migration and invasion of MCF-7 cells, up-regulated the protein level of E-cadherin, and down-regulated those of MMP-2 and Snail, as suggested by the MCF-7 cell experiment. According to the results from in vivo experiment, tryptanthrin was effective in inhibiting tumor growth, and it showed favorable safety without inducing the fluctuations of body mass and organ coefficient (p > 0.05). In addition, tryptanthrin also suppressed the expression levels of NOS1, COX-2 and NF-κB in mouse tumor tissues, and regulated those of IL-2, IL-10 and TNF-α in the serum of tumor cells-transplanted mice. Tryptanthrin exerted its anti-breast cancer activities through modulating the inflammatory TME both in vitro and in vivo.

Indigo enhances wound healing activity of Caco-2 cells via activation of the aryl hydrocarbon receptor

Indigo Naturalis, also known as Qing Dai (QD) is a compound obtained from Indigofera tinctoria, Isatis tinctoria, and Polygonum tinctoria and is known to ameliorate refractory ulcerative colitis (UC) by an unknown mechanism. QD maintains both homeostasis and the integrity of colon epithelia in mice that have experimentally induced colitis. The primary component of QD, indigo, comprises 42.4% of the compound. Indigo efficiently suppresses rectal bleeding and reduces the erosion of the colon epithelium, whereas it does not reduce weight loss or increase survival in a certain condition. Indigo is a ligand of the aryl hydrocarbon receptor (AhR), which is involved in the anti-colitis activity of QD. Here we investigate the effects of indigo on wound (erosion) closure in colon epithelial cells. Oral administration of indigo induced expression of Cytochrome P450 1A1 (Cyp1a1) in the colon but not in the liver, suggesting that indigo stimulates AhR from the luminal side of the colon. The erosion-closure activity tested in the scratch assays using Caco-2 cells was accelerated by addition of QD and indigo to the culture medium. QD and indigo also induced nuclear localization of AhR and expression of CYP1A1 in the Caco-2 cells. Acceleration of scratch wound closure was abolished by addition of the AhR-antagonist CH223191. Cell proliferation and actin polymerization were also shown to contribute to erosion closure. The results suggest that indigo exerts its erosion-healing effects by increasing proliferation and migration of colon epithelial cells via activation of AhR in intestinal epithelia.

Identification of Mutations Conferring Tryptanthrin Resistance to Mycobacterium smegmatis

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is a global burden, responsible for over 1 million deaths annually. The emergence and spread of drug-resistant M. tuberculosis strains (MDR-, XDR- and TDR-TB) is the main challenge in global TB-control, requiring the development of novel drugs acting on new biotargets, thus able to overcome the drug-resistance. Tryptanthrin is a natural alkaloid, with great therapeutic potential due to its simple way of synthesis and wide spectrum of biological activities including high bactericidal activity on both drug-susceptible and MDR M. tuberculosis strains. InhA was suggested as the target of tryptanthrins by in silico modeling, making it a promising alternative to isoniazid, able to overcome drug resistance provided by katG mutations. However, neither the mechanism of action of tryptanthrin nor the mechanism of resistance to tryptanthrins was ever confirmed in vitro. We show that the MmpS5-MmpL5 efflux system is able to provide resistance to tryptanthrins using an in-house test-system. Comparative genomic analysis of spontaneous tryptanthrin-resistant M. smegmatis mutants showed that mutations in MSMEG_1963 (EmbR transcriptional regulator) lead to a high-level resistance, while those in MSMEG_5597 (TetR transcriptional regulator) to a low-level one. Mutations in an MFS transporter gene (MSMEG_4427) were also observed, which might be involved in providing a basal level of tryptanthrins-resistance.

Anti-inflammatory and bioavailability studies on dietary 3,5,4'-trihydroxy-6,7-methylenedioxyflavone-O-glycosides and their aglycone from indigo leaves in a murine model of inflammatory bowel disease

Persicaria tinctoria (Aiton) Spach, also called Polygonum tinctorium Lour., (family Polygonaceae) for indigo plant has been traditionally useful as a medicinal or edible plant with a variety of biological activities. Of these, much attention has been paid to their anti-inflammatory activities. We have recently demonstrated that indigo leaves contain high levels of flavonol O-glycosides with 3,5,4'-trihydroxy-6,7-methylenedioxyflavone (TMF) as an aglycone. In this study, we attempted to evaluate anti-inflammatory activities of TMF-O-glycosides and free TMF prepared from indigo leaves after extraction with hot water. Free TMF was found to appreciably down-regulate the gene expression of pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, inducible nitric oxide, and tumor necrosis factor-α in cultured macrophage cells stimulated with lipopolysaccharide while up-regulating the expression of anti-inflammatory IL-10. However, no study has been conducted regarding in vivo anti-inflammatory activities of TMF-O-glycosides and free TMF until now. Here, we assessed in vivo anti-inflammatory effects of these dietary compounds on ulcerative colitis in a murine model of inflammatory bowel disease by the induction with dextran sulfate sodium (DSS). Histological evaluation revealed that both TMF-O-glycosides and free TMF effectively protected against DSS-induced ulcerative colitis. The analysis of digested products by liquid chromatography and mass spectrometry led us to detect free TMF as a predominant metabolite in the feces of mice fed with TMF-O-glycosides. Moreover, free TMF was later detected as glucuronyl conjugates of TMF in the liver of mice fed with both fractions. These results indicate the effective digestion of TMF-O-glycosides and the subsequent absorption of free TMF in the gut of mice for exerting anti-inflammatory effects. Taken together, our findings suggest that dietary TMF-O-glycosides could be promising natural sources for the utilization as herbal medicine and nutraceuticals to expect in vivo anti-inflammatory activities.

Nutritional Interventions Using Functional Foods and Nutraceuticals to Improve Inflammatory Bowel Disease

The gastrointestinal tract, the second largest organ in the body, plays an important role in nutrient and mineral intake through the intestinal barrier. Dysfunction of intestinal permeability and related disorders commonly occur in patients with inflammatory bowel disease (IBD), one of the health problems in the Western societies that are considered to be mainly due to the Western diet. Although the exact etiology of IBD has not been elucidated, environmental and genetic factors may be involved in its pathogenesis. Many synthetic or biological drugs, such as 5-aminosalicylic acid corticosteroids as anti-inflammatory drugs, have been used clinically to treat IBD. However, their long-term use exhibits some adverse health consequences. Therefore, many researchers have devised alternative therapies to overcome this problem. Many studies have revealed that some functional nutrients in nature can relieve gastrointestinal inflammation by controlling proinflammatory cytokines. In this study, we review the ability of functional nutraceuticals such as phytochemicals, fatty acids, and bioactive peptides in improving IBD by regulating its underlying pathogenic mechanisms.

Mechanisms of indigo naturalis on treating ulcerative colitis explored by GEO gene chips combined with network pharmacology and molecular docking

Oral administration of indigo naturalis (IN) can induce remission in ulcerative colitis (UC); however, the underlying mechanism remains unknown. The main active components and targets of IN were obtained by searching three traditional Chinese medicine network databases such as TCMSP and five Targets fishing databases such as PharmMapper. UC disease targets were obtained from three disease databases such as DrugBank,combined with four GEO gene chips. IN-UC targets were identified by matching the two. A protein–protein interaction network was constructed, and the core targets were screened according to the topological structure. GO and KEGG enrichment analysis and bioGPS localization were performed,and an Herbs-Components-Targets network, a Compound Targets-Organs location network, and a Core Targets-Signal Pathways network were established. Molecular docking technology was used to verify the main compounds-targets. Ten core active components and 184 compound targets of IN-UC, of which 43 were core targets, were enriched and analyzed by bioGPS, GO, and KEGG. The therapeutic effect of IN on UC may involve activation of systemic immunity, which is involved in the regulation of nuclear transcription, protein phosphorylation, cytokine activity, reactive oxygen metabolism, epithelial cell proliferation, and cell apoptosis through Th17 cell differentiation, the Jak-STAT and IL-17 signaling pathways, toll-like and NOD-like receptors, and other cellular and innate immune signaling pathways. The molecular mechanism underlying the effect of IN on inducing UC remission was predicted using a network pharmacology method, thereby providing a theoretical basis for further study of the effective components and mechanism of IN in the treatment of UC.

Nanocrystalline ZnO: A Competent and Reusable Catalyst for the Preparation of Pharmacology Relevant Heterocycles in the Aqueous Medium

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Nanoparticle catalyzed synthesis is a green and convenient method to achieve most of the chemical transformations in water or other green solvents. Nanoparticle ensures an easy isolation process of catalyst as well as products from the reaction mixture avoiding the hectic work up procedure. Zinc oxide is a biocompatible, environmentally benign and economically viable nanocatalyst with effectivity comparable to the other metal nanocatalyst employed in several reaction strategies. This review mainly focuses on the recent applications of zinc oxide in the synthesis of biologically important heterocyclic molecules under sustainable reaction conditions.

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Application of zinc oxide in organic synthesis: Considering the achievable advantages of this nanocatalyst, presently several research groups are paying attention in anchoring zincoxide or its modified structure in several types of organic conversions e.g. multicomponent reactions, ligand-free coupling reactions, cycloaddition reaction, etc. The advantages and limitations of this nanocatalyst are also demonstrated. The present study aims to highlight the recent multifaceted applications of ZnO towards the synthesis of diverse heterocyclic motifs. Being a promising biocompatible nanoparticle, this catalyst has an important contribution in the fields of synthetic chemistry and medicinal chemistry.

Isatis tinctoria L. (Woad): A Review of its Botany, Ethnobotanical Uses, Phytochemistry, Biological Activities, and Biotechnological Studies

Isatis tinctoria L. (Brassicaceae), which is commonly known as woad, is a species with an ancient and well-documented history as an indigo dye and medicinal plant. Currently, I. tinctoria is utilized more often as medicinal remedy and also as a cosmetic ingredient. In 2011, I. tinctoria root was accepted in the official European phytotherapy by introducing its monograph in the European Pharmacopoeia. The biological properties of raw material have been known from Traditional Chinese Medicine (TCM). Over recent decades, I. tinctoria has been investigated both from a phytochemical and a biological point of view. The modern in vitro and in vivo scientific studies proved anti-inflammatory, anti-tumour, antimicrobial, antiviral, analgesic, and antioxidant activities. The phytochemical composition of I. tinctoria has been thoroughly investigated and the plant was proven to contain many valuable biologically active compounds, including several alkaloids, among which tryptanthrin, indirubin, indolinone, phenolic compounds, and polysaccharides as well as glucosinolates, carotenoids, volatile constituents, and fatty acids. This article provides a general botanical and ethnobotanical overview that summarizes the up-to-date knowledge on the phytochemistry and biological properties of this valuable plant in order to support its therapeutic potential. Moreover, the biotechnological studies on I. tinctoria, which mainly focused on hairy root cultures for the enhanced production of flavonoids and alkaloids as well as on the establishment of shoot cultures and micropropagation protocols, were reviewed. They provide input for future research prospects.

Comparison of the anti-colitis activities of Qing Dai/Indigo Naturalis constituents in mice

Qing Dai/Indigo Naturalis (QD) has been shown to ameliorate ulcerative colitis (UC) in clinical trials; however, its mechanism remains elusive. This study investigates the effects of QD on murine dextran sulfate sodium salt-induced colitis. Oral administration of QD protected the animals from colitis as manifested by weight loss, diarrhea, and rectal bleeding. QD was distinguishingly more effective than 5-aminosalicylate. Focused microarray analysis of genes expressed in the distal colon suggested that QD influences the inflammatory pathway. Anti-inflammatory activity of QD was confirmed by the suppression of nitric oxide (NO) production in response to interleukin-1β in cultured hepatocytes. Some of the constituents in QD, such as tryptanthrin (TRYP) and indigo, suppressed NO production. TRYP maintained body weight but did not inhibit bleeding. Indigo, on the other hand, partially ameliorated bleeding, but did not maintain body weight. The combination of TRYP and indigo did not show additive ameliorating activity. The methanol extract of QD showed an anti-colitis activity like that of TRYP. In contrast, the methanol-insoluble QD fraction moderately ameliorated diarrhea and bleeding. Combining these two fractions resulted in full anti-colitis activity. Further clarification of the active constituents will help in the discovery of a safe and potent prescription for UC.

Phytotherapies in inflammatory bowel disease

Inflammatory bowel disease (IBD) has been considered as a group of heterogeneous intestinal diseases that affects multiple organs outside of the gastrointestinal tract and is due to an uncontrolled inflammatory response mediated by the immune system. The IBD etiology has not been clearly defined, and it is considered as a multifactorial disease. Due to side effects of some conventional therapies, the consumption of complementary and alternative medicines, and in particular, the herbal therapy, more than before is increasing. Herbal therapy results for management of IBD by various mechanisms including leukotriene B4 inhibition, antioxidant activity, immune system regulation of nuclear factor-kappa B, as well as antiplatelet activity are favorable, and no unfortunate events have been yet reported. In this article, we aimed to review and report the herbal therapies established for management of human IBD or evaluated by animal IBD models. Their possible mechanisms of actions are also discussed.

Plant-Derived Alkaloids: The Promising Disease-Modifying Agents for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) represents a group of intestinal disorders with self-destructive and chronic inflammation in the digestive tract, requiring long-term medications. However, as many side effects and drug resistance are frequently encountered, safer and more effective agents for IBD treatment are urgently needed. Over the past few decades, a variety of natural alkaloids made of plants or medicinal herbs have attracted considerable interest because of the excellent antioxidant and anti-inflammatory properties; additionally, these alkaloids have been reported to reduce the colonic inflammation and damage in a range of colitic models. In this review paper, we summarize the recent findings regarding the anti-colitis activity of plant-derived alkaloids and emphasize their therapeutic potential for the treatment of IBD; obvious improvement of the colonic oxidative and pro-inflammatory status, significant preservation of the epithelial barrier function and positive modulation of the gut microbiota are the underlying mechanisms for the plant-derived alkaloids to treat IBD. Further clinical trials and preclinical studies to unravel the molecular mechanism are essential to promote the clinical translation of plant-derived alkaloids for IBD.

Constituents of flavonol O-glycosides and antioxidant activities of extracts from seeds, sprouts, and aerial parts of Polygonum tinctorium Lour

Polygonum tinctorium Lour. (family Polygonaceae), known as indigo plant, has been useful as a medicinal or edible plant abundant in polyphenolic compounds. We have recently shown that flavonol O-glycosides with 3,5,4′-trihydroxy-6,7-methylenedioxyflavone (TMF) are predominant flavonoids in indigo leaves. However, no study has been performed regarding changes in the levels of flavonoid species during the germination and growth of indigo plant. Here, we attempted to determine the individual constituents of flavonol O-glycosides and the changes in their contents of the seeds, sprouts, and aerial parts. These results revealed that only the seeds predominantly contained flavonol O-(acetyl)-rhamnosides with quercetin or kaempferol as an aglycone. During the development of the sprouts and aerial parts, flavonol O-glycosides with TMF as an aglycone became mainly detectable and accounted for 79.4% and 74.9% of total flavonol O-glycosides from the extracts of aerial parts harvested in 2016 and 2017, respectively. Of the plant organs tested, the aerial parts exhibited the highest antioxidant activities concomitant with greatly increased levels of total polyphenols. Thus, we were able to conduct the identification and quantification of flavonol O-glycosides from the seeds, sprouts, and aerial parts of indigo plant and to evaluate antioxidant activities of their extracts. Taken together, our findings clearly provide the evidence that the aerial parts of indigo plant are a rich source of flavonol O-glycosides with TMF and exhibit much higher antioxidant activities, indicating the usefulness for the application to food and nutraceutical purposes.

Biologically active quinoline and quinazoline alkaloids part I

Quinoline and quinazoline alkaloids, two important classes of N-based heterocyclic compounds, have attracted tremendous attention from researchers worldwide since the 19th century. Over the past 200 years, many compounds from these two classes were isolated from natural sources, and most of them and their modified analogs possess significant bioactivities. Quinine and camptothecin are two of the most famous and important quinoline alkaloids, and their discoveries opened new areas in antimalarial and anticancer drug development, respectively. In this review, we survey the literature on bioactive alkaloids from these two classes and highlight research achievements prior to the year 2008 (Part I). Over 200 molecules with a broad range of bioactivities, including antitumor, antimalarial, antibacterial and antifungal, antiparasitic and insecticidal, antiviral, antiplatelet, anti-inflammatory, herbicidal, antioxidant and other activities, were reviewed. This survey should provide new clues or possibilities for the discovery of new and better drugs from the original naturally occurring quinoline and quinazoline alkaloids.

Study on pharmacokinetics and tissue distribution of single dose oral tryptanthrin in Kunming mice by validated reversed-phase high-performance liquid chromatography with ultraviolet detection

Background

Tryptanthrin is a major active constituent of several Chinese herbal plants, such as Isatidis radix. Tryptanthrin had been demonstrated to have several beneficial pharmacological effects in vitro for human diseases, including antitumor, anti-inflammatory and antibacteria activities. In contrast to the extensive in vitro investigations, the in vivo disposition process of tryptanthrin was explored limitedly.

Methods

In this study, the pharmacokinetics (PK) and tissue distribution of tryptanthrin in Kunming mice following a single oral dose of 80 mg/kg tryptanthrin were investigated for the first time. Mouse plasma, liver, heart, spleen, lung, kidney and brain were collected and analyzed using a validated reversed-phase high-performance liquid chromatography with ultraviolet detection (RP-HPLC–UV) method after biological sample preparation by a simple liquid–liquid extraction.

Results

The chromatographic analysis was performed on a Diamonsil C₁₈ column (5 μm, 250 mm × 4.6 mm) and ultraviolet detection was set at a wavelength of 251 nm. The analysis was achieved with a mobile phase of methanol (A) and water (B) (60:40, v/v) at a flow rate of 1.0 mL/min. The method was linear over the concentration range of 4.0–400.0 μg/mL with a lower limit of quantification of 0.10–0.30 μg/mL. Inter- and intraday precisions (relative standard deviations %) were all within 2.93%. Recoveries of tryptanthrin were more than 86.44%. Maximal tryptanthrin concentrations in plasma and tissues of mice were reached within 2.5 hours. The actual highest concentration (C_max) in mouse plasma was 3.13 μg/mL, the area under the curve (AUC_0–t) was 9.38 h μg/mL, and the terminal half-life was 2.27 hours. The volume of distribution was 343.89 mL, the clearance rate was 204.58 mL/h, and the PK of tryptanthrin in mice after oral administration was fit to 2 compartment 1 st Order. After oral dosing of tryptanthrin to Kunming mice, the analyte was well distributed to the plasma and main tissues. C_max was found in the liver with a mean value of 3.54 μg/g, followed by that in the kidney, lung, spleen, heart, and brain.

Conclusion

In this study, a validated RP-HPLC–UV method was developed and successfully applied to PK and tissue distribution of oral tryptanthrin in mice. We confirmed that tryptanthrin was closely related and targeted to plasma, liver, kidney, and lung. These results indicate that tryptanthrin will have a good clinical application in the liver, kidney, or lung. The clinical use of tryptanthrin should focus on its pharmacodynamics and safety study in these tissues.

The Pathogenetic Effect of Natural and Bacterial Toxins on Atopic Dermatitis

Atopic dermatitis (AD) is a common allergic skin disease that is associated with chronic, recurrent eczematous and pruritic lesions at the flexural folds caused by interacting factors related to environmental and immune system changes. AD results in dry skin, and immunoglobulin E-mediated allergic reactions to foods and environmental allergens. While steroids and anti-histamines temporarily relieve the symptoms of AD, the possibility of side effects from pharmacological interventions remains. Despite intensive research, the underlying mechanisms for AD have not been clarified. A study of Staphylococcus aureus (S. aureus) established the role of its toxins in the pathogenesis of AD. Approximately 90% of patients with AD experience S. aureus colonization and up to 50%–60% of the colonizing S. aureus is toxin-producing. Any damage to the protective skin barrier allows for the entry of invading allergens and pathogens that further drive the pathogenesis of AD. Some natural toxins (or their components) that have therapeutic effects on AD have been studied. In addition, recent studies on inflammasomes as one component of the innate immune system have been carried out. Additionally, studies on the close relationship between the activation of inflammasomes and toxins in AD have been reported. This review highlights the literature that discusses the pathogenesis of AD, the role of toxins in AD, and the positive and negative effects of toxins on AD. Lastly, suggestions are made regarding the role of inflammasomes in AD.

Quercetin and Tryptanthrin: Two Broad Spectrum Anticancer Agents for Future Chemotherapeutic Interventions

The idea and practice of developing or identifying compounds capable of eliminating the transformed cells or cancer cells without being nontoxic to their normal counterparts deserves much importance. Since ages, plants have been considered and proven to be repertoires of chemicals possessing immense therapeutic potential. A proportion of these plant-derived compounds or phytochemicals were shown to be highly competent anticancer agents besides being effective against many other diseases. Representative compounds of different classes of phytochemicals are in clinical use against cancer. In this chapter, we discuss the anticancer potential of two compounds: quercetin, a flavonoid and tryptanthrin, an indoloquinazoline alkaloid, and the mechanisms behind their cytotoxic effects on cancers of different origin. The chapter also gives a brief mention of their properties that make them effective against cancer.

Genuine traditional Korean medicine, Naju Jjok (Chung-Dae, Polygonum tinctorium) improves 2,4-dinitrofluorobenzene-induced atopic dermatitis-like lesional skin

PURPOSE

Naju Jjok (NJJ, Polygonum tinctorium) is a clear heat and release toxin medicinal. It has been used to treat various inflammatory diseases and as a dye in clothing in traditional Korean medicine. However, the effect of NJJ on atopic dermatitis (AD) has not been elucidated. Therefore, we examined whether NJJ would have an inhibitory effect on AD using the mimic AD murine model and in vitro model.

METHODS

We treated NJJ on 2,4-dinitrofluorobenzene (DNFB)-induced AD-like skin lesions in NC/Nga mice, phorbol myristate acetate/calcium ionophore A23187-stimulated human mast cell line (HMC-1) cells, and anti-CD3/anti-CD28-stimulated splenocytes. Histological analysis, ELISA, PCR, and Western blot analysis were performed.

RESULTS

The oral administration with NJJ suppressed the total clinical severity in DNFB-induced AD-like lesional skin. NJJ significantly suppressed the levels of inflammatory mRNA and protein in AD-like lesional skin. NJJ significantly suppressed the levels of IgE and interleukin-4 in the serum of DNFB-induced AD mice. The expression of mast cells-derived caspase-1 was suppressed by NJJ in AD-like lesional skin. In addition, topical application with NJJ improved clinical symptoms in DNFB-induced AD mice. The topical application with NJJ significantly suppressed the levels of IgE and histamine in the serum of DNFB-induced AD mice. NJJ suppressed the production and mRNA expression of TSLP by blockade of caspase-1 signal pathway in the activated HMC-1 cells. Furthermore, NJJ significantly decreased the production of tumor necrosis factor-α from the stimulated splenocytes.

CONCLUSIONS

In conclusion, these results propose curative potential of natural dye, NJJ by showing the scientific evidence on anti-AD effect of NJJ which has been used traditionally.

Identification and quantitative analysis of polyphenolic compounds from the indigo plant (Polygonum tinctorium Lour)

The indigo plant (Polygonum tinctorium Lour) has been used traditionally as a medicinal plant with a variety of biological effects. Of these, polyphenolic ingredients are postulated to contribute to these activities. However, the identification and quantification of polyphenolic compounds in indigo plants have not been conducted comprehensively until now. This study was undertaken to identify the related ingredients by combined instrumental analyses using ultra-performance liquid chromatography electrospray-ionisation mass spectrometry and gas chromatography-mass spectrometry after the extracts of plant tissues were fractionated by absorption column chromatography. These analyses allowed the identification of kaempferol, quercetin-3-O-glucuronide, quercetin, kaempferol-3-O-glucopyranoside, caffeic acid, chlorogenic acid and tentative 3,5,4'-trihydroxy-6,7-methylenedioxyflavone. Furthermore, predominant polyphenolic compounds were quantified by reverse-phase high-performance liquid chromatography and capillary gas chromatography, revealing the higher proportions of kaempferol, quercetin-3-O-glucuronide and quercetin among them. The results indicate that the indigo plant is a promising source for flavonoids and the related compounds with beneficial medicinal effects.

On the inhibition of 5-lipoxygenase product formation by tryptanthrin: mechanistic studies and efficacy in vivo

BACKGROUND AND PURPOSE

Leukotrienes (LTs) are pro-inflammatory mediators produced by 5-lipoxygenase (5-LO). Currently available 5-LO inhibitors either lack efficacy or are toxic and novel approaches are required to establish a successful anti-LT therapy. Here we provide a detailed evaluation of the effectiveness of the plant-derived alkaloid tryptanthrin as an inhibitor of LT biosynthesis.

EXPERIMENTAL APPROACH

We analysed LT formation and performed mechanistic studies in human neutrophils stimulated with pathophysiologically relevant stimuli (LPS and formyl peptide), as well as in cell-free assays (neutrophil homogenates or recombinant human 5-LO) and in human whole blood. The in vivo effectiveness of tryptanthrin was evaluated in the rat model of carrageenan-induced pleurisy.

KEY RESULTS

Tryptanthrin potently reduced LT-formation in human neutrophils (IC(50) = 0.6µM). However, tryptanthrin is not a redox-active compound and did not directly interfere with 5-LO activity in cell-free assays. Similarly, tryptanthrin did not inhibit the release of arachidonic acid, the activation of MAPKs, or the increase in [Ca(2+) ](i) , but it modified the subcellular localization of 5-LO. Moreover, tryptanthrin potently suppressed LT formation in human whole blood (IC(50) = 10µM) and reduced LTB(4) levels in the rat pleurisy model after a single oral dose of 10mg·kg(-1) .

CONCLUSIONS AND IMPLICATIONS

Our data reveal that tryptanthrin is a potent natural inhibitor of cellular LT biosynthesis with proven efficacy in whole blood and is effective in vivo after oral administration. Its unique pharmacological profile supports further analysis to exploit its pharmacological potential.

Proliferation-attenuating and apoptosis-inducing effects of tryptanthrin on human chronic myeloid leukemia K562 cell line in vitro

Tryptanthrin, a kind of indole quinazoline alkaloid, has been shown to exhibit anti-microbial, anti-inflammation and anti-tumor effects both in vivo and in vitro. However, its biological activity on human chronic myeloid leukemia cell line K562 is not fully understood. In the present study, we investigated the proliferation-attenuating and apoptosis-inducing effects of tryptanthrin on leukemia K562 cells in vitro and explored the underlying mechanisms. The results showed that tryptanthrin could significantly inhibit K562 cells proliferation in a time- and dose-dependent manner as evidenced by MTT assay and flow cytometry analysis. We also observed pyknosis, chromatin margination and the formation of apoptotic bodies in the presence of tryptanthrin under the electron microscope. Nuclei fragmentation and condensation by Hoechst 33258 staining were detected as well. The amount of apoptotic cells significantly increased whereas the mitochondrial membrane potential decreased dramatically after tryptanthrin exposure. K562 cells in the tryptanthrin treated group exhibited an increase in cytosol cyt-c, Bax and activated caspase-3 expression while a decrease in Bcl-2, mito cyt-c and pro-caspase-3 contents. However, the changes of pro-caspase-3 and activated caspase-3 could be abolished by a pan-caspase inhibitor ZVAD-FMK. These results suggest that tryptanthrin has proliferation-attenuating and apoptosis-inducing effects on K562 cells. The underlying mechanism is probably attributed to the reduction in mitochondria membrane potential, the release of mito cyt-c and pro-caspase-3 activation.

Tryptanthrin inhibits Th2 development, and IgE-mediated degranulation and IL-4 production by rat basophilic leukemia RBL-2H3 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Tryptanthrin is a compound isolated from Polygonum tinctorium, which is a known folk medicine with various biological activities.

AIM OF THE STUDY

Allergic diseases are initiated by the development of allergen-specific T helper type 2 (Th2) cells and amplified by the degranulation of and cytokine release from basophils and mast cells during an effector phase. We found that Tryptanthrin could down-regulate IL-4 production by Th2 cells, while IFN-γ production by Th1 cells was not affected. Since IL-4 produced by basophils and effector Th2 cells has been shown to play important roles in the development and amplification of Th2-dominated allergic responses, we examined the effects of Tryptanthrin on the initiation and effector phase responses of Type I allergy in vitro.

MATERIALS AND METHODS

To determine the mechanisms of Tryptanthrin-induced down-regulation of IL-4 production, the expression of Th2-specific transcription factors, c-Maf and GATA-3, was analyzed by RT-PCR. The effects of Tryptanthrin on Th cell differentiation were evaluated using CD4(+) T cells purified from spleen cells of Sugi basic protein (SBP)-immunized BALB/c mice. In primary cultures, cells were stimulated with SBP and antigen-presenting cells under neutral or Th2-skewing conditions in the presence or absence of Tryptanthrin. Cytokines produced by differentiated Th cells in secondary cultures were analyzed by ELISA. The effects of Tryptanthrin on IgE-mediated degranulation and IL-4 production were determined using rat basophilic leukemia (RBL-2H3) cells. Phosphorylation of ERK1/2 and Akt in Tryptanthrin-treated RBL-2H3 cells was analyzed to determine the mechanism of Tryptanthrin actions.

RESULTS

Tryptanthrin suppressed c-Maf mRNA expression in Th2 clone cells, and even under Th2-skewing conditions, Tryptanthrin inhibited differentiation toward the Th2 phenotype, which is an essential event for the initiation phase of allergic diseases. Tryptanthrin also inhibited the IgE-mediated degranulation of and IL-4 production by RBL-2H3 cells, probably due to inhibiting IgE-mediated signaling pathways, including the phosphorylation of ERK1/2 and Akt.

CONCLUSION

These findings suggest that Tryptanthrin effectively inhibits the effector and exacerbation responses, as well as the initiator responses, of Type I allergy. Thus, Tryptanthrin may have beneficial effects for immediate-type allergic responses.

On the use of herbal medicines in management of inflammatory bowel diseases: a systematic review of animal and human studies

Because of potential adverse events and lack of effectiveness of standard therapies, the use of complementary and alternative medicines (CAM), particularly of herbal therapies, for inflammatory bowel disease (IBD) is increasing. Results from the use of herbal therapies for managing IBD are promising, and no serious adverse events have been reported from them. Herbal therapies show their benefit in managing IBD by different mechanisms such as immune system regulation, antioxidant activity, inhibition of leukotriene B4, inhibition of nuclear factor-kappa B (NF-kappaB), and antiplatelet activity. In this paper, all reported herbal therapies established in animal IBD models or used for managing human IBD are systematically reviewed and their possible mechanisms of action discussed. Conducting clinical trials with high quality and validity (randomized, double blinded, controlled, on a large number of patients) to obtain more conclusive results about the use of herbal therapies in IBD is recommended.

An arachidonic acid-enriched diet does not result in more colonic inflammation as compared with fish oil- or oleic acid-enriched diets in mice with experimental colitis

Fish oils (FO) – rich in EPA and DHA – may protect against colitis development. Moreover, inflammatory bowel disease patients have elevated colonic arachidonic acid (AA) proportions. So far, effects of dietary AAv.FO on colitis have never been examined. We therefore designed three isoenergetic diets, which were fed to mice for 6 weeks preceding and during 7 d dextran sodium sulfate colitis induction. The control diet was rich in oleic acid (OA). For the other two diets, 1·0 % (w/w) OA was exchanged for EPA+DHA (FO group) or AA. At 7 d after colitis induction, the AA group had gained weight (0·46 (sem0·54) g), whereas the FO and OA groups had lost weight ( − 0·98 (sem0·81) g and − 0·79 (sem1·05) g, respectively;P < 0·01v.AA). The AA group had less diarrhoea than the FO and OA groups (P < 0·05). Weight and length of the colon, histological scores and cytokine concentrations in colon homogenates showed no differences. Myeloperoxidase concentrations in plasma and polymorphonuclear cell infiltration in colon were decreased in the FO group as compared with the OA group. We conclude that in this mice model an AA-enriched diet increased colonic AA content, but did not result in more colonic inflammation as compared with FO- and OA-enriched diets. As we only examined effects after 7 d and because the time point for evaluating effects seems to be important, the present results should be regarded as preliminary. Future studies should further elucidate differential effects of fatty acids on colitis development in time.

Tryptanthrin inhibits interferon-gamma production by Peyer's patch lymphocytes derived from mice that had been orally administered staphylococcal enterotoxin

Tryptanthrin, a biologically active compound found in the medicinal plant Polygonum tinctorium, reportedly has several biological activities. We investigated the effects of tryptanthrin on cytokine production by lymphocytes in response to staphylococcal enterotoxin B (SEB), which causes a variety of disorders in humans based on its induction of large amounts of immunostimulatory cytokines. Tryptanthrin dose-dependently inhibited interferon-gamma (IFN-gamma) and interleukin-2 production by mouse spleen cells and Peyer's patch (PP) lymphocytes in vitro. The efficacy of tryptanthrin was further studied in a mouse model in vivo. Tryptanthrin was administered orally 2 h after an oral challenge with SEB. Nineteen hours after SEB administration, PP lymphocytes were prepared, and IFN-gamma production by PP lymphocytes was examined. The production of IFN-gamma increased after SEB administration, and the elevated IFN-gamma production was significantly inhibited by tryptanthrin treatment. These results suggest that tryptanthrin may be effective in the treatment of disorders of the intestines, such as food poisoning, that are associated with activated lymphocytes.