Novel treatments for inflammatory bowel disease

Tiron ameliorates acetic acid-induced colitis in rats: Role of TGF-β/EGFR/PI3K/NF-κB signaling pathway

BACKGROUND

Ulcerative colitis (UC), an ongoing inflammatory disorder of the colon, is marked by persistent mucosal surface irritation extending from the rectum to the near-proximal colon. Tiron is a synthetic analogue of vitamin E which is known to have antioxidant and anti-inflammatory effects in various animal models, so the goal of this study was to find out whether Tiron had any preventive impacts on UC inflicted by acetic acid (A.A) exposure in rats.

METHOD

Tiron (235 and 470 mg/kg) was administered intra-peritoneally for 2 weeks, and A.A (2 ml, 3 % v/v) was injected intra-rectally to cause colitis. Colon tissues and blood samples were then collected for measurement of various inflammatory and oxidative stress biomarkers.

RESULTS

Tiron administration significantly diminished lactate dehydrogenase (LDH), C-reactive protein (CRP), colon weight, and the weight/length ratio of the colon as compared to A.A-injected rats. Additionally, Tiron attenuated oxidative stress biomarkers. Tiron also enforced the levels of Glucagon-like peptide-1 (GLP-1) and trefoil factor-3 (TFF-3), while it greatly lowered the expression of nuclear factor kappa B (NF-κB), interleukin-6 (IL-6), interferon-γ (IFN-γ), and transforming growth factor-1(TGF-β1), phosphorylated epidermal growth factor receptor (P-EGFR), phosphatidylinositol-3-kinase (PI3K) and protein kinase B (AKT) expression in colonic cellular structures. Furthermore, colonichistopathologic damages, revealed by hematoxylin and eosin (H&E) and Alcian Blue stain, were significantly decreased upon Tiron administration.

CONCLUSION

Tiron prevented A.A-induced colitis in rats via modulating inflammatory pathway TGF-β1/P-EGFR/PI3K/AKT/NF-κB, alongside managing the oxidant/antioxidant equilibrium, and boosting the reliability of the intestinal barrier.

Electrical carotid sinus nerve stimulation attenuates experimental colitis induced by acetic acid in rats

AIMS

The carotid bodies are sensors that detect physiological signals and convey them to the central nervous system, where the stimuli are processed inducing reflexes through efferent pathways. Recent studies have demonstrated that electrical stimulation of the carotid sinus nerve (CSN) triggers the anti-inflammatory reflex under different conditions. However, whether this electrical stimulation attenuates colitis was never examined. This study aimed to evaluate if the electrical CSN stimulation attenuates the experimental colitis induced by intrarectal administration of acetic acid in rats.

METHODS

Electrodes were implanted around the CSN to stimulate the CSN, and a catheter was inserted into the left femoral artery to record the arterial pressure. The observation of hypotensive responses confirmed the effectiveness of the electrical CNS stimulation. This maneuver was followed by a 4 % acetic acid or saline administered intrarectally. After 24 h, colons were segmented into distal and proximal parts for macroscopy, histological and biochemical assessment.

KEY FINDINGS

As expected, the electrical CSN stimulation was effective in decreasing arterial pressure in saline and colitis rats. Moreover, electrical CSN stimulation effectively reduced colonic tissue lesions, colitis scores, and histopathologic parameters associated with colitis. In addition, the CSN stimulation also reduced the colonic mucosa pro-inflammatory cytokine interleukin-1 beta, and increased the anti-inflammatory interleukin-10, in rats submitted to colitis.

SIGNIFICANCE

These findings indicated that electrical CSN stimulation breaks the vicious cycle of local colon inflammation in colitis, which might contribute to its better outcome.

APE1/Ref-1 as a Therapeutic Target for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is characterized by chronic relapsing inflammation of the gastrointestinal tract. The prevalence of IBD is increasing with approximately 4.9 million cases reported worldwide. Current therapies are limited due to the severity of side effects and long-term toxicity, therefore, the development of novel IBD treatments is necessitated. Recent findings support apurinic/apyrimidinic endonuclease 1/reduction-oxidation factor 1 (APE1/Ref-1) as a target in many pathological conditions, including inflammatory diseases, where APE1/Ref-1 regulation of crucial transcription factors impacts significant pathways. Thus, a potential target for a novel IBD therapy is the redox activity of the multifunctional protein APE1/Ref-1. This review elaborates on the status of conventional IBD treatments, the role of an APE1/Ref-1 in intestinal inflammation, and the potential of a small molecule inhibitor of APE1/Ref-1 redox activity to modulate inflammation, oxidative stress response, and enteric neuronal damage in IBD.

Ileo-Anal Pouch Anastomosis and New Remedial Approaches for Ulcerative Colitis: A Review Article

Ulcerative colitis (UC) causes diffuse friability and superficial wall degeneration that is accompanied by bleeding. UC, now recognized as a global illness, affects millions of people globally. The most effective treatment for UC is Ileal Pouch Anal Anastomosis (IPAA). Many medical experts and patients favor proctocolectomy with IPAA because it improves bowel function and allows feces to pass via the anus. Considering the most recent research, systematic reviews, statistical analysis, and recommendations, a selective literature search was carried out. The database used was PubMed. The current work provides a summary of surgical alternatives, results, and pre-and postoperative treatment for UC patients. In the course of their illness, about 30% of UC patients will need surgery. Due to its natural limitation to the colon and rectum, UC may mostly be treated surgically. The preferred surgical process is a restorative proctocolectomy with an IPAA. A 30% postoperative complication rate and a 0.1% death rate for this operation are both shown in large studies. One of the biggest things preventing UC from being successfully treated surgically is pouchitis. A long-run success rate of the pouch is >90% after 10 follow-ups, despite a significant surgical complication rate. For patients with UC to have the best possible outcome, extensive collaboration among the various specialties in the pre and postoperative context is crucial. In skilled centers, more than 90% of the total patients can eventually achieve a decent quality of life despite a 30% likelihood of early postoperative problems. UC patients may be cured with proctocolectomy, but there is a risk of morbidity that must be considered, especially in pediatric patients. As a result of advancements in our comprehension of the pathogenic mechanisms causing UC, new therapies have been proposed, the most significant change being the emergence of anti-tumor necrosis factor (TNF) medications.

Therapeutic Efficacy of Novel HDAC Inhibitors SPA3052 and SPA3074 against Intestinal Inflammation in a Murine Model of Colitis

Inflammatory bowel diseases (IBD) are digestive tract disorders that involve chronic inflammation with frequent recurrences. This study aimed to evaluate the efficacy of two novel histone deacetylase 8 (HDAC8) inhibitors, namely, SPA3052 and SPA3074, against dextran sulfate sodium (DSS)-induced experimental colitis. Male C57BL/6N mice were subjected to two cycles of 1.5% DSS followed by treatment with suberoylanilide hydroxamic acid (SAHA), SPA3052, or SPA3074 for 14 days. Our results showed that SPA3074 administration increased (>50%) the expression of occludin, a tight junction protein, which was significantly decreased (>100%) after DSS treatment. Moreover, SPA3074 upregulated suppressor of cytokine signaling 1 (SOCS1) protein expression, which is known to be a key suppressor of T-helper cell differentiation and pro-inflammatory cytokines expression. Furthermore, we observed a decrease in SOCS1-associated Akt phosphorylation and an increase in lower extracellular signal-regulated kinase 1 and 2 phosphorylation, which contributed to lower nuclear factor-kappa B activation. Th2 effector cytokines, especially interleukin-13, were also downregulated by SPA3074 treatment. This study suggests that HDAC8 might be a promising novel target for the development of IBD treatments and that the novel HDAC8 inhibitor SPA3074 is a new candidate for IBD therapeutics.

Vaccination strategies for Korean patients with inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) are vulnerable to vaccine-preventable infectious diseases. Immunosuppressive drugs, which are often used to manage IBD, may increase this vulnerability and attenuate vaccine efficacy. Thus, healthcare providers should understand infectious diseases and schedule vaccinations for them to reduce the infection-related burden of patients with IBD. All patients with IBD should be assessed in terms of immunity to vaccine-preventable diseases at the time of IBD diagnosis, and be vaccinated appropriately. Vaccination is becoming more important because of the unprecedented coronavirus disease 2019 (COVID-19) global health crisis. This review focuses on recent updates to vaccination strategies for Korean patients with IBD.

Inflammatory bowel disease in Korea: epidemiology and pathophysiology

Inflammatory bowel disease (IBD) refers to a group of disorders, including Crohn's disease and ulcerative colitis, that exhibit similar but distinct manifestations. These diseases are characterized by refractory and chronic inflammation of the bowel. IBD is usually accompanied by severe symptoms. When a patient presents with suspected IBD, physicians encounter various challenges in terms of diagnosis and treatment. In addition, given such characteristics, the associated medical expenses gradually increase. Although IBD was formerly known as a disease of Western countries, the incidence and prevalence are increasing in Korea. Korean investigators have accumulated a great deal of knowledge about the regional characteristics and epidemiology of the disease, especially via well-organized, joint cohort studies. Against this background, this article describes the epidemiology of IBD in Korea compared to that in the West. In addition, an overview of the pathophysiology of the disease is provided, focusing on the latest results.

Management of inflammatory bowel disease beyond tumor necrosis factor inhibitors: novel biologics and small-molecule drugs

The incidence and prevalence of inflammatory bowel disease (IBD), comprising Crohn's disease and ulcerative colitis, have increased in Asia and developing countries. In the past two decades, anti-tumor necrosis factor (TNF) agents have revolutionized the treatment of IBD, in part by decreasing the rates of complications and surgery. Although anti-TNF agents have changed the course of IBD, there are unmet needs in terms of primary and secondary non-responses and side effects such as infections and malignancies. Novel biologics and small-molecule drugs have been developed for IBD, and the medical treatment options have improved. These drugs include sphingosine-1-phosphate receptor modulators and anti-integrins to block immune cell migration, and cytokine and Janus kinase inhibitors to block immune cell communications. In this review, we discuss the approved novel biologics and small-molecule drugs, including several of those in the late stages of development, for the treatment of IBD.

IBD therapeutics: what is in the pipeline?

Inflammatory bowel disease (IBD) is an idiopathic long-term relapsing and remitting disorder including ulcerative colitis and Crohn's disease. The aim of therapy is to induce and maintain remission. Anti-TNF therapies dramatically improved clinical outcomes but primary failure or secondary loss is a common problem as well as potential side effects potentially limiting efficacy and long-term use. The advent of new targeted agents with the potential for greater safety is welcomed in IBD and offers the potential for different agents as the disease becomes refractory or even combination therapies to maximise effectiveness without compromising safety in the future. More data are required to understand the best positioning in pathways and longer-term safety effects.

Helicobacter pylori infection in patients with inflammatory bowel diseases: a single-centre, prospective, observational study in Egypt

OBJECTIVE

Conflicting results have been reported by numerous epidemiological studies investigating the association between Helicobacter pylori (H. pylori) infection and inflammatory bowel disease (IBD). We aimed in this study to assess the possible association between H. pylori infection and IBD and its effects on disease progression.

DESIGN

Prospective observational study.

SETTING

Specialised IBD care clinics at Alexandria University Student Hospital in northern Egypt, between March and June 2019.

PARTICIPANTS

182 patients with IBD.

ANALYSIS AND OUTCOME MEASURES

Participants with IBD were screened for H. pylori infection and clinically evaluated at the initial visit and bimonthly for 3 months to record any potential improvement/flare of the IBD condition.

RESULTS

Overall, 90 (49.5%) patients with IBD had evidence of H. pylori infection. The course of IBD did not significantly differ in association with H. pylori infection or IBD treatment strategy. Cox regression analysis revealed that patients aged 20-35 years (HR=6.20 (95% CI: 1.74 to 22.12)) and 35-55 years (557.9 (17.4-17 922.8)), high socioeconomic status (2.9 (1.11-7.8)), daily consumption of fibre-rich food (5.1 (1.32-19.5)), occasional consumption of snacks between meals (2.8 (2.5-70.5)) and eating four meals per day (13.3 (1.0-7.7)) were predictive of IBD flare. By contrast, eating fruits and vegetables showed a strongly protective association (HR=0.001 (95% CI: 0.0002 to 0.02)). The probabilities of improvement of IBD symptoms after 12 weeks of follow-up were comparable in assessments based on H. pylori infection status (0.793 for H. pylori negative vs 0.778 for H. pylori positive) and IBD treatment option (0.811 for conventional therapy vs 0.750 for biological therapy).

CONCLUSION

The association between IBD and H. pylori infection is unresolved and should be further investigated in the context of specific environmental exposures that can influence the development or relapse of IBD.

Preventive empagliflozin activity on acute acetic acid-induced ulcerative colitis in rats via modulation of SIRT-1/PI3K/AKT pathway and improving colon barrier

BACKGROUND

Ulcerative colitis (UC) is a chronic colon inflammation that is linked to exposure to environmental factors leading to improper immune responses to enteric microbes in genetically susceptible individuals. This study was designed to explore the possible protective impact of Empagliflozin (EMPA), an anti-diabetic sodium-glucose cotransporter-2 (SGLT2) inhibitor, on acetic acid (AA)-induced UC in rats.

METHOD

Intrarectal instillation of AA (2 ml, 3% v/v) was used to induce UC. EMPA (10 & 30 mg/kg) was administered orally for 11 days.

RESULTS

EMPA successfully counteracted AA-induced UC that was manifested by improving colonic histopathological architecture concomitant with a marked decrease in disease activity index (DAI), colon weight, weight/length ratio, serum lactate dehydrogenase (LDH) activity, and C-reactive protein (CRP) level. Additionally, EMPA successfully restored the disrupted oxidant/antioxidants balance induced by AA. Moreover, EMPA significantly induced silent information regulator-1(SIRT-1) expression along with a significant reduction in phosphatidylinositol-3-Kinase (PI3K), Protein Kinase B (AKT), nuclear factor kappa B (NF-κB), tumor necrosis factor (TNF)-α and interleukins (IL-1β and IL-6) expression in colonic tissues. Furthermore, EMPA successfully improved the colonic barrier that was appeared from the marked induction of tight junction proteins level (occludin and claudin-1).

CONCLUSION

EMPA successfully counteracted AA-induced UC in rats via the modulation of SIRT1/PI3K/AKT/NF-κB inflammatory pathway, normalizing oxidant/antioxidants balance, and improving the integrity of colon barrier.

Risk of Thromboembolic Events and Associated Healthcare Costs in Patients with Inflammatory Bowel Disease

Introduction

Inflammatory bowel disease (IBD) is associated with greater risk of thromboembolic events (TEs) due to the link between systemic inflammation and hypercoagulability. This study assessed the rates of TEs among patients with IBD versus patients without immune-mediated disease (IMD) and the cost of TEs among patients with IBD in the United States.

Methods

This study used the IBM MarketScan^® Commercial and Medicare Supplemental Databases (2014–2018). To assess the incremental rates of TEs (deep vein thrombosis [DVT], pulmonary embolism [PE], ischemic stroke [IS], myocardial infarction [MI]), patients with IBD were matched to patients without IMD. Unadjusted and adjusted incidence rate ratios (IRRs) of TEs were used to compare cohorts. To assess the cost of TEs, patients with IBD with TEs were matched to patients with IBD without TEs. Costs were assessed 30 days and 1 year post index date.

Results

There were 34,687 matched pairs included in the rates of TE analyses. Compared to patients without IMD, patients with IBD had greater rates of DVT (adjusted IRR [95% confidence interval] 2.44 [2.00, 2.99]; p < 0.01) and PE (1.90 [1.42, 2.54]; p < 0.01). Increased rates were not observed for IS and MI. There were 1885 matched pairs included in the cost of TE analyses. Patients with IBD with TEs incurred greater healthcare costs over 30 days and 1 year versus patients without TEs (adjusted total cost difference: 30 days $20,784; 1 year $44,630; p < 0.01 for both).

Conclusions

Patients with IBD experienced greater rates of DVT and PE compared to patients without IMD; this elevated risk was associated with a substantial economic burden.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01973-7.

Therapeutic effects of dihydroartemisinin in multiple stages of colitis-associated colorectal cancer

Colitis-associated colorectal cancer (CAC) develops from chronic intestinal inflammation. Dihydroartemisinin (DHA) is an antimalarial drug exhibiting anti-inflammatory and anti-tumor effects. Nonetheless, the therapeutic effects of DHA on CAC remain unestablished.

Methods: Mice were challenged with azoxymethane (AOM) and dextran sulfate sodium (DSS) to establish CAC models. DHA was administered via oral gavage in different stages of CAC models. Colon and tumor tissues were obtained from the AOM/DSS models to investigate inflammatory responses and tumor development. Inflammatory cytokines in the murine models were detected through qRT-PCR and ELISA. Toll-like receptor 4 (TLR4) signaling-related proteins were detected by western blot. Macrophage infiltration was measured using immunostaining analysis, and apoptosis in the colon cancer cells was detected by flow cytometry and western blot.

Results: DHA inhibited inflammatory responses in the early stage of the AOM/DSS model and subsequent tumor formation. In the early stage, DHA reversed macrophage infiltration in colon mucosa and decreased the expression of pro-inflammatory cytokines. DHA inhibited the activation of macrophage by suppressing the TLR4 signal pathway. In the late stage of CAC, DHA inhibited tumor growth by enhancing cell cycle arrest and apoptosis in tumor cells. Administration of DHA during the whole period of the AOM/DSS model generated an addictive effect based on the inhibition of inflammation and tumor growth, thereby improving the therapeutic effect of DHA on CAC.

Conclusion: Our study indicated that DHA could be a potent agent in managing the initiation and development of CAC without obvious side effects, warranting further clinical translation of DHA for CAC treatment.

Experimental Evaluation of the Impact of Gadolinium Orthovanadate GdVO4:Eu3+ Nanoparticles on the Carrageenan-Induced Intestinal Inflammation

AIM

To evaluate the effects of orally administered gadolinium orthovanadate GdVO4:Eu3+ nanoparticles (VNPs) on the course of chronic carrageenan-induced intestinal inflammation.

METHODS

Samples of small intestinal tissue were collected from four groups of rats (intact, after administration of VNPs, with carrageenaninduced intestinal inflammation, with carrageenan-induced intestinal inflammation orally exposed to VNPs) to assess the intestinal morphology and HSP90α expression. Levels of seromucoid, C-reactive protein, TNF-α, IL-1β and IL-10 were determined in blood serum.

RESULTS

Oral exposure to VNPs was associated with neither elevation of inflammation markers in blood serum nor HSP90α overexpression in the small intestine, i.e. no toxic effects of VNPs were observed. Carrageenan-induced intestinal inflammation was accompanied by higher levels of TNF-α and IL-1β, as well as HSP90α upregulation in the intestinal mucosa, compared with controls. Administration of VNPs to rats with enteritis did not lead to statistically significant changes in concentrations of circulating pro-inflammatory cytokines with the trend towards their increase.

CONCLUSION

No adverse effects were observed in rats orally exposed to VNPs at a dose of 20 μg/kg during two weeks. Using the experimental model of carrageenan-induced enteritis, it was demonstrated that VNPs at the dose used in our study did not affect the course of intestinal inflammation.

Inflammatory bowel disease: tri-directional relationship between microbiota, immune system and intestinal epithelium

Human gut microbiota contributes to host nutrition and metabolism, sustains intestinal cell proliferation and differentiation, and modulates host immune system. The alterations in their composition lead to severe gut disorders, including inflammatory bowel disease (IBD) or inflammatory bowel syndrome (IBS). IBD including ulcerative colitis (UC) and Crohn's disease (CD) are gamut of chronic inflammatory disorders of gut, mediated by complex interrelations among genetic, environmental, and internal factors. IBD has debateable aetiology, however in recent years, exploring the central role of a tri-directional relationship between gut microbiota, mucosal immune system, and intestinal epithelium in pathogenesis is getting the most attention. Increasing incidences and early onset explains the exponential rise in IBD burden on health-care systems. Industrialization, hypersensitivity to allergens, lifestyle, hygiene hypothesis, loss of intestinal worms, and gut microbial composition, explains this shifted rise. Hitherto, the interventions modulating gut microbiota composition, microfluidics-based in vitro gastrointestinal models, non-allergic functional foods, nutraceuticals, and faecal microbiota transplantation (FMT) from healthy donors are some of the futuristic approaches for the disease management.

Elucidation of colon-protective efficacy of diosgenin in experimental TNBS-induced colitis: inhibition of NF-κB/IkB-α and Bax/Caspase-1 signaling pathways

The aim of present investigation was to elucidate the unrevealed beneficial role of diosgenin against an experimental model of TNBS (2,4,6-trinitrobenzenesufonic acid)-induced ulcerative colitis (UC). Colitis was induced in Sprague-Dawley rats by intrarectal administration of TNBS (in 50% ethanol). Then animals were treated with diosgenin (50, 100, and 200 mg/kg) for 14 days. Various biochemical, behavioral, molecular, and histological analysis was performed. Diosgenin significantly decreased (p < 0.05) TNBS-induced elevated colonic oxido-nitrosative damage, myeloperoxidase, hydroxyproline, mRNA expressions of proinflammatory cytokines (TNF-α, IL-1β, IL-6, and IFN-γ) and inflammatory markers (iNOs and COX-2) induced by TNBS. Western blot analysis relevated that TNBS-induced up-regulated protein expressions of NF-κB, IκBα, Bax, and Caspase-1 were markedly decreased (p < 0.05) by diosgenin treatment. It also markedly ameliorated the histological insults induced in the colon by TNBS. In conclusion, diosgenin exerts its colon-protective efficacy probably through the inhibition of NF-κB/IkB-α and Bax/Caspase-1 signaling pathways to experimental TNBS-induced ulcerative colitis.

ABBREVIATIONS

ANOVA: Analysis of variance; 5-ASA: 5-aminosalicylic acid; Bax: Bcl-2-associated X protein; COX-2: Cyclooxygenase-2; DAI: Disease Activity Index; DMSO: Dimethyl sulfoxide; GAPDH: Glyceraldehyde 3-phosphate dehydrogenase; GSH: Glutathione; HP: Hydroxyproline; IAEC: International Animal Ethics Committee; IBD: Inflammatory Bowel Disease; IBS: Inflammatory Bowel Syndrome; IL's: Interleukin's; IFN-γ: Interferon-gamma; IκBα: nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha; iNOs: Inducible nitric oxide synthase; LTB4: Leukotriene B4; MDA: Malondialdehyde; MPO: Myeloperoxidase; NO: Nitric Oxide; NF-κB: Nuclear Factor-κB; ROS: Reactive Oxygen Species; SOD: Superoxide Dismutase; TNBS: Trinitrobenzene Sulfonic Acid; TNF-α: Tumor necrosis factor-α.

In vivo Imaging Technologies to Monitor the Immune System

The past two decades have brought impressive advancements in immune modulation, particularly with the advent of both cancer immunotherapy and biologic therapeutics for inflammatory conditions. However, the dynamic nature of the immune response often complicates the assessment of therapeutic outcomes. Innovative imaging technologies are designed to bridge this gap and allow non-invasive visualization of immune cell presence and/or function in real time. A variety of anatomical and molecular imaging modalities have been applied for this purpose, with each option providing specific advantages and drawbacks. Anatomical methods including magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound provide sharp tissue resolution, which can be further enhanced with contrast agents, including super paramagnetic ions (for MRI) or nanobubbles (for ultrasound). Conjugation of the contrast material to an antibody allows for specific targeting of a cell population or protein of interest. Protein platforms including antibodies, cytokines, and receptor ligands are also popular choices as molecular imaging agents for positron emission tomography (PET), single-photon emission computerized tomography (SPECT), scintigraphy, and optical imaging. These tracers are tagged with either a radioisotope or fluorescent molecule for detection of the target. During the design process for immune-monitoring imaging tracers, it is important to consider any potential downstream physiologic impact. Antibodies may deplete the target cell population, trigger or inhibit receptor signaling, or neutralize the normal function(s) of soluble proteins. Alternatively, the use of cytokines or other ligands as tracers may stimulate their respective signaling pathways, even in low concentrations. As in vivo immune imaging is still in its infancy, this review aims to describe the modalities and immunologic targets that have thus far been explored, with the goal of promoting and guiding the future development and application of novel imaging technologies.

Immunoproteasome inhibitor DPLG3 attenuates experimental colitis by restraining NF-κB activation

Inflammatory bowel disease is a chronic and pathologic autoimmune condition. And immunoproteasome is becoming an attractive therapeutic target for autoimmune inflammatory diseases. In this study, we evaluated the therapeutic effects of a specific small molecule inhibitor of the chymotryptic-like β5i subunits of the immunoproteasome, DPLG3, in a preclinical murine colitis model and explored the underlying molecular mechanism for the immune suppression. DPLG3 showed significant effects in attenuating the disease progression in experimental colitis, reducing the body and spleen weight losses, and colon length shortening compared to vehicle-treated controls and to the well studied immunoproteasome inhibitor ONX-0914. Mechanistically, DPLG3 decreased inflammatory cytokines and the influx of effector T cells and macrophages in colon tissues while increasing the number of regulatory T cells. Molecular docking analysis of the protein-ligand interaction profile revealed that the β5i-DPLG3 complex was more stable and efficient in the binding sites compared to those formed with ONX-0914 and LU-005i. Furthermore, DPLG3 reduced the protein levels of the canonical NF-κB p50 and p65, as well as the nuclear p65. Thus, DPLG3 constitutes a potentially efficacious clinical agent for autoimmune inflammatory diseases.

Organometallic Compounds and Metal Complexes in Current and Future Treatments of Inflammatory Bowel Disease and Colorectal Cancer-a Critical Review

In recent years, there has been a significant increase in the clinical use of organometallic compounds and metal complexes for therapeutic purposes including treatment of inflammatory bowel diseases (IBD). Their action is based on the inhibition of the inflow of pro-inflammatory cytokines, the elimination of free radicals or the modulation of intestinal microbiota. In addition, these compounds are intended for use in the diagnosis and treatment of colorectal cancer (CRC) which is often a consequence of IBD. The aim of this study is to critically discuss recent findings on the use of organometallic compounds and metal complexes in the treatment of IBD and CRC and suggest future trends in drug design.

Novel drug delivery systems of Chinese medicine for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is an idiopathic intestinal inflammatory disease that comprises ulcerative colitis (UC) and Crohn's disease (CD). IBD involves the ileum, rectum, and colon, and common clinical manifestations of IBD are diarrhea, abdominal pain, and even bloody stools. Currently, non-steroidal anti-inflammatory drugs, glucocorticoids, and immunosuppressive agents are used for the treatment of IBD, while their clinical application is severely limited due to unwanted side effects. Chinese medicine (CM) is appealing more and more attention and investigation for the treatment of IBD owing to the potent anti-inflammation pharmacological efficacy and high acceptance by patients. In recent years, novel drug delivery systems are introduced apace to encapsulate CM and many CM-derived active constituents in order to improve solubility, stability and targeting ability. In this review, advanced drug delivery systems developed in the past and present to deliver CM for the treatment of IBD are summarized and future directions are discussed.

High-dimensional single-cell proteomics analysis identifies immune checkpoint signatures and therapeutic targets in ulcerative colitis

Immune checkpoints are regulators of immune cells and play key roles in the modulation of immune responses. The role of checkpoints in autoimmune disease is poorly understood but likely to be central since checkpoint inhibition during cancer treatment can cause autoimmunity. We generated a high-dimensional single-cell proteomics data set from PBMCs of healthy individuals and patients with ulcerative colitis (UC) by mass cytometry, enabling systems-wide analyses of immune cell frequencies and cell type-specific expression patterns of 12 immune checkpoints. Subtle but significant changes in immune cell frequencies and checkpoint expression were observed between UC patients on different treatment regimens and between patients and healthy controls. Most strikingly, UC patients showed a reduced number of peripheral NK-cells and those cells showed an altered phenotype including increased TIGIT expression. Based on these results, we modulated NK-cell function ex vivo through targeting of TIGIT pathway members. In summary, we describe a pattern of changes in immune cell abundance and checkpoint expression as a basis for UC patient stratification and we show modulation of a corresponding immune cell subset through checkpoint targeting. Our approach can be used for the identification of pathogenic immune cell subsets and guide target selection in autoimmunity and chronic inflammation.

Zeaxanthin exerts protective effects on acetic acid-induced colitis in rats via modulation of pro-inflammatory cytokines and oxidative stress

Ulcerative colitis is a common intestinal inflammatory disease characterized by upregulation of pro-inflammatory cytokines and oxidative stress. Zeaxanthin is a nutritional carotenoid that belongs to the xanthophyll family of pigments. It exerts potent anti-inflammatory and antioxidative effects. The present study aimed to evaluate the effect of zeaxanthin on acetic acid-induced ulcerative colitis in rats. Rats were randomly categorized into five groups: control, zeaxanthin, acetic acid, acetic acid + zeaxanthin, and acetic acid + prednisolone groups. Zeaxanthin (50 mg/kg/day) or prednisolone (5 mg/kg/day) was orally administered for 14 days before induction of ulcerative colitis. On the 15th day, colitis was induced by transrectal administration of 3% acetic acid. The rats were sacrificed 24 h after rectal instillation and their colon tissues were examined. Pretreatment with zeaxanthin significantly reduced disease activity index, wet colon weight, ulcer area, macroscopic scores, and histological changes. Zeaxanthin also effectively downregulated the levels of myeloperoxidase and malondialdehyde, upregulated the enzymatic activity of superoxide dismutase and catalase, and raised glutathione levels. With regard to anti-inflammatory mechanisms, zeaxanthin suppressed tumor necrosis factor-alpha, interferon-gamma, interleukin-6, interleukin-1 beta, and nuclear transcription factor kappa B levels, and inhibited nitric oxide synthase and cyclooxygenase-2 protein expression. Our results indicate that oral administration of zeaxanthin ameliorates acetic acid-induced colitis in rats via antioxidative effects and modulation of pro-inflammatory cytokine and mediator activity. Therefore, zeaxanthin may be an effective therapeutic candidate for the treatment of ulcerative colitis.

Impact of Modern Drug Therapy on Surgery: Ulcerative Colitis

Background

The primary treatment of ulcerative colitis (UC) is conservative, and substantial therapeutic progress has been made in the past few decades. Meanwhile, biologicals have become a mainstay in the treatment for steroid-refractory UC. Despite further development of drug therapy and an increased time span to operation, a significant proportion of patients with UC require surgical intervention. Surgical intervention needs to be carried out in medically refractory cases, imminent or malignant transformation, or complications. This article discusses the impact of modern drug therapy on surgery for UC.

Methods

A selective literature search of PubMed was conducted, taking into account current studies, reviews, meta-analyses, and guidelines. Selected articles were then reviewed in detail and recommendations were drafted based on data and conclusions of the articles.

Results

In recent years, modern drug therapy has changed the timing, approach, and outcomes of surgery for UC. Most of the studies showed a decrease in surgery rates over time while the rate of emergency colectomies remains unchanged. So far, no convincing surgery-sparing effect of newer medications has been established, and it remains debatable if surgery rates have decreased because of improved management for UC in general or due to the introduction of biologicals. The intensified conservative therapy with increasing use of biologics has been accompanied by a trend towards performing a three-step procedure in the last decade. There is a subset of patients with complex refractory disease who most likely benefit from elective surgery as an alternative to prolonged conservative therapies after failure of first-line treatment. The majority of patients after ileal pouch-anal anastomosis can avoid hospitalizations and colitis-related medications with their associated potential adverse effects. In addition, the procedure substantially reduces UC-related symptoms and the risk for dysplasia or cancer. There is a long-term pouch success rate of >90% after 10 and 20 years of follow-up.

Conclusion

Conservative medical therapy in the treatment of UC will continue to develop and the number of approved therapeutics will grow. Surgery should not be considered as the negative endpoint of treatment modalities but as a good alternative to a prolonged conservative therapy for some patients. In conclusion, a close cooperation between the various disciplines in the pre- and postoperative management is essential in order to optimize the timing and outcome of patients with UC.

Drug Lag for Inflammatory Bowel Disease Treatments in the East and West

Background

Inflammatory bowel disease (IBD), though historically common in the West, is now increasingly prevalent in industrializing countries. A simultaneous dramatic increase in IBD drug options has enabled most patients to achieve remission. Nevertheless, worldwide disparities in the approval of IBD drugs, or "drug lag", remain problematic.

Summary

Drug lag for major IBD drugs before March 31, 2018 (12 for Crohn's disease [CD] and 13 for ulcerative colitis [UC]) was compared between that of the United States (US), European Union (EU), and Asia (Japan, China, South Korea, Taiwan, and the Philippines) to assess current trends. In the US, unapproved IBD drugs accounted for 16.7% (2/12) for CD and 23.1% (3/13) for UC; approval lag was 3.8 (0-80.5) months for CD and 3.6 (0-88) months for UC. In the EU, unapproved drugs accounted for 16.7% (2/12) for CD and 15.4% (2/13) for UC; approval lag was 0.03 (0-13.9) months for CD and 0 (0-13.9) months for UC. This demonstrates the short drug lag in both regions, although one drug developed in a joint US/EU clinical trial had around a 350-day approval lag. In Asia, the proportion of unapproved IBD drugs was the lowest in Japan at 33.3% (4/12) for CD and 23.1% (3/13) for UC; South Korea had the shortest lag for CD at 13.2 (0-133.1) months and the Philippines had the shortest lag for UC at 9.9 (0.6-176.2) months, but these countries still had longer lag periods than the West. However, a proportion of unapproved drugs and approval lag has decreased considerably in Asia since the start of the biologics era.

Key Messages

Despite the recent shortening drug lag between different countries and regions, this study shows that disparities persist. With globalization, eliminating these disparate drug lags is necessary to manage IBD and may require efforts toward international adoption of a more standardized approval process.

Epidemiology, disease burden, and treatment challenges of ulcerative colitis in Africa and the Middle East

Ulcerative colitis is an idiopathic, chronic, inflammatory bowel disorder characterized by an unpredictable course of alternating cycles of relapse and remission. Traditionally viewed as a disease of Western countries, the prevalence of ulcerative colitis is reported to be increasing in the developing world. In these regions, there is the potential to further explore the etiology of the disease, mainly through genetic studies. With this in mind, we consider available data relating to the epidemiology, clinical manifestations, and disease course of ulcerative colitis in Africa and the Middle East. Current treatment approaches in these countries are also reviewed and discussed in the context of new, small molecule, orally administered therapies. Areas covered: Available data on the epidemiology, clinical manifestations, and risk factors of ulcerative colitis in Africa and the Middle East are reviewed using a PubMed database search. Expert commentary: Epidemiologic studies from African and Middle Eastern countries suggest disease trends similar to the West, and an important health and economic burden. The management of ulcerative colitis within these developing countries is challenging, with the need to improve early diagnosis, access to healthcare, and patient education, along with facilitation of access to treatment options and improvement of medication adherence.