Recent advances in basic and clinical aspects of inflammatory bowel disease: Which steps in the mucosal inflammation should we block for the treatment of inflammatory bowel disease?

Saudi consensus guidance for the diagnosis and management of inflammatory bowel disease in children and adolescents

ABSTRACT

The management of inflammatory bowel disease (IBD) in children and adolescents is challenging. Clear evidence-based guidelines are required for this population. This article provides recommendations for managing IBD in Saudi children and adolescents aged 6-19 years, developed by the Saudi Ministry of Health in collaboration with the Saudi Society of Clinical Pharmacy and the Saudi Gastroenterology Association. All 57 guideline statements are based on the most up-to-date information for the diagnosis and management of pediatric IBD.

Ellagic Acid Prevented Dextran-Sodium-Sulfate-Induced Colitis, Liver, and Brain Injury through Gut Microbiome Changes

Inflammatory bowel disease (IBD) affects millions of people worldwide and is considered a significant risk factor for colorectal cancer. Recent in vivo and in vitro studies reported that ellagic acid (EA) exhibits important antioxidant and anti-inflammatory properties. In this study, we investigated the preventive effects of EA against dextran sulfate sodium (DSS)-induced acute colitis, liver, and brain injury in mice through the gut-liver-brain axis. Acute colitis, liver, and brain injury were induced by treatment with 5% (w/v) DSS in the drinking water for 7 days. Freshly prepared EA (60 mg/kg/day) was orally administered, while control (CON) group mice were treated similarly by daily oral administrations with a vehicle (water). All the mice were euthanized 24 h after the final treatment with EA. The blood, liver, colon, and brain samples were collected for further histological and biochemical analyses. Co-treatment with a physiologically relevant dose (60 mg/kg/day) of EA for 7 days significantly reduced the DSS-induced gut barrier dysfunction; endotoxemia; and inflammatory gut, liver, and brain injury in mice by modulating gut microbiota composition and inhibiting the elevated oxidative and nitrative stress marker proteins. Our results further demonstrated that the preventive effect of EA on the DSS-induced IBD mouse model was mediated by blocking the NF-κB and mitogen-activated protein kinase (MAPK) pathway. Therefore, EA co-treatment significantly attenuated the pro-inflammatory and oxidative stress markers by suppressing the activation of NF-κB/MAPK pathways in gut, liver, and brain injury. These results suggest that EA, effective in attenuating IBD in a mouse model, deserves further consideration as a potential therapeutic for the treatment of inflammatory diseases.

Nutraceuticals' Novel Formulations: The Good, the Bad, the Unknown and Patents Involved

Traditional nutraceuticals and cosmeceuticals hold pragmatic nature with respect to their definitions, claims, purposes and marketing strategies. Their definitions are not well established worldwide. They also have different regulatory definitions and registration regulatory processes in different parts of the world. Global prevalence of nutraceuticals and cosmeceuticals is noticeably high with large market share with minimal regulation compared to traditional drugs. The global market is flooded with nutraceuticals and cosmeceuticals claiming to be of natural origin and sold with a therapeutic claim by major online retail stores such as Amazon and eBay. Apart from the traditional formulations, many manufacturers and researchers use novel formulation technologies in nutraceutical and cosmeceutical formulations for different reasons and objectives. Manufacturers tend to differentiate their products with novel formulations to increase market appeal and sales. On the other hand, researchers use novel strategies to enhance nutraceuticals and cosmeceuticals activity and safety. The objective of this review is to assess the current patents and research adopting novel formulation strategies in nutraceuticals and cosmeceuticals. Patents and research papers investigating nutraceutical and cosmeceutical novel formulations were surveyed for the past 15 years. Various nanosystems and advanced biotechnology systems have been introduced to improve the therapeutic efficacy, safety and market appeal of nutraceuticals and cosmeceuticals, including liposomes, polymeric micelles, quantum dots, nanoparticles, and dendrimers. This review provides an overview of nutraceuticals and cosmeceuticals current technologies, highlighting their pros, cons, misconceptions, regulatory definitions and market. This review also aims in separating the science from fiction in the nutraceuticals and cosmeceuticals development, research and marketing.

Effects of Probiotics on Gut Microbiota in Patients with Inflammatory Bowel Disease: A Double-blind, Placebo-controlled Clinical Trial

BACKGROUND/AIMS

Several clinical trials have revealed various advantages for probiotics in inflammatory bowel disease (IBD). The aim of this study was to further investigate the effects of probiotic yogurt consumption on gut microbiota in patients with this disease.

METHODS

A total of 305 participants were divided into three groups; group A (IBD patients receiving probiotic yogurt; n=105), group B (IBD patients receiving placebo; n=105), and control group (healthy individuals receiving probiotic yogurt; n=95). Stool samples were collected both before and after 8 weeks of intervention; and population of Lactobacillus, Bifidobacterium and Bacteroides in the stool specimens was measured by Taqman real-time PCR method.

RESULTS

By the end of the intervention, no significant variations in the mean weight and body mass index were observed between three groups (p>0.05). However, the mean numbers of Lactobacillus, Bifidobacterium, and Bacteroides in group A were significantly increased compared to group B (p<0.001, p<0.001, and p< 0.01, respectively). There were also significant differences in the mean numbers of either of three bacteria between group A and the healthy control group; however, these differences between two groups were observed both at baseline and the end of the intervention.

CONCLUSIONS

Consumption of probiotic yogurt by patients with IBD may help to improve intestinal function by increasing the number of probiotic bacteria in the intestine and colon. However, many more studies are required in order to prove the concept.

WISP1 Is Increased in Intestinal Mucosa and Contributes to Inflammatory Cascades in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is mainly characterized by intestinal tissue damage, which is caused by excessive autoimmune responses poorly controlled by corresponding regulatory mechanisms. WISP1, which belongs to the CCN protein family, is a secreted matricellular protein regulating several inflammatory pathways, such as Wnt/β-catenin pathway, and has been reported in several diseases including cancer. Here we examined the expression, regulatory mechanisms, and functions of WISP1 in IBD. WISP1 mRNA and protein expression was upregulated in colonic biopsies and lamina propria mononuclear cells (LPMC) of IBD patients compared with those of healthy controls. Tumor necrosis factor- (TNF-) α induced WISP1 expression in LPMC from healthy controls. Consistently, WISP1 mRNA expression was downregulated in colonic biopsies from IBD patients who had achieved clinical remission with infliximab (IFX). Furthermore, WISP1 expression was also found to be increased in colons from 2,4,6-trinitrobenzenesulfonic acid- (TNBS-) induced mice compared with those from control mice. Further studies confirmed that administration of rWISP1 could aggravate TNBS-induced colitis in vivo. Therefore, we concluded that WISP1 is increased in IBD and contributes to the proinflammatory cascades in the gut.

Intestinal anti-inflammatory activity of luteolin: role of the aglycone in NF-κB inactivation in macrophages co-cultured with intestinal epithelial cells

The flavonoid luteolin is reported to exert anti-inflammatory properties. In this study, we investigated whether luteolin inhibits gut inflammation, using in vivo and in vitro inflammation models. In a dextran sulfate sodium (DSS)-induced colitis mouse model, luteolin (20 and 50 mg/kg) significantly ameliorated shortening of colon length and histological score. Immunohistochemical analysis showed that luteolin also significantly inhibited infiltration of macrophages and interferon (IFN)-γ-producing CD4⁺ T cells into the colonic mucosa. Treatment with luteolin also improved IFN-γ mRNA expression in the colon. At the cellular level, a co-culture consisting of intestinal epithelial Caco-2 and macrophage RAW264.7 cells, stimulated with lipopolysaccharide, the addition of luteolin (100 μM) suppressed interleukin (IL)-8 mRNA expression in Caco-2 cells without epithelial monolayer disruption. Expression of tumor necrosis factor (TNF)-α protein and proinflammatory cytokines mRNA (TNF-α, IL-6, and IL-1β) in RAW264.7 cells were also suppressed. HPLC analysis and subsequent cellular assay revealed that aglycone of luteolin was present in the basolateral supernatant of this system at a sufficient concentration to suppress TNF-α production and nuclear factor (NF)-κB activation of RAW264.7 cells. These results suggest that the luteolin aglycones released from the Caco-2 epithelium inhibits NF-κB nuclear translocation in RAW264.7 cells, followed by reduction of TNF-α mRNA expression, which results in downregulation of IL-8 mRNA expression in Caco-2 cells. The mechanism by which aglycone inhibits inflammation is important for understanding the roles of luteolin in diet.

IL-23/IL-17A axis correlates with the nitric oxide pathway in inflammatory bowel disease: immunomodulatory effect of retinoic acid

Inflammatory bowel diseases (IBDs) are chronic inflammatory diseases of the gastrointestinal tract, which are clinically present as 1 of the 2 disorders, Crohn's disease (CD) or ulcerative colitis (UC) (Rogler 2004). The immune dysregulation in the intestine plays a critical role in the pathogenesis of IBD, involving a wide range of molecules, including cytokines. The aim of this work was to study the involvement of T-helper 17 (Th17) subset in the bowel disease pathogenesis by the nitric oxide (NO) pathway in Algerian patients with IBD. We investigated the correlation between the proinflammatory cytokines [(interleukin (IL)-17, IL-23, and IL-6] and NO production in 2 groups of patients. We analyzed the expression of messenger RNAs (mRNAs) encoding Th17 cytokines, cytokine receptors, and NO synthase 2 (NOS2) in plasma of the patients. In the same way, the expression of p-signal transducer and activator of transcription 3 (STAT3) and NOS2 was measured by immunofluorescence and immunohistochemistry. We also studied NO modulation by proinflammatory cytokines (IL-17A, IL-6, tumor necrosis factor α, or IL-1β) in the presence or absence of all-trans retinoic acid (At RA) in peripheral blood mononuclear cells (PBMCs), monocytes, and in colonic mucosa cultures. Analysis of cytokines, cytokine receptors, and NOS2 transcripts revealed that the levels of mRNA transcripts of the indicated genes are elevated in all IBD groups. Our study shows a significant positive correlation between the NO and IL-17A, IL-23, and IL-6 levels in plasma of the patients with IBD. Interestingly, the correlation is significantly higher in patients with active CD. Our study shows that both p-STAT3 and inducible NOS expression was upregulated in PBMCs and colonic mucosa, especially in patients with active CD. At RA downregulates NO production in the presence of proinflammatory cytokines for the 2 groups of patients. Collectively, our study indicates that the IL-23/IL-17A axis plays a pivotal role in IBD pathogenesis through the NO pathway.

Mucosal intestinal alteration in experimental colitis correlates with nitric oxide production by peritoneal macrophages: effect of probiotics and prebiotics

Inflammatory bowel disease (IBD) consists mainly of Ulcerative colitis (UC) and Crohn disease (CD). Although its aetiology is still not clearly established, it is thought to be due to overly aggressive immune response to enteric bacteria in genetically predisposed individuals. Manipulating the microbiota using probiotics or prebiotics is considered as a promising field of new therapeutic strategies used to attenuate immune disorders observed during IBD. The production of nitric oxide (NO) seems to be implicated in IBD pathogenesis. In our study, an acute UC was induced in Swiss mice using 3% Dextran Sulfate Sodium (DSS). The preventive effects of "Ultrabiotique®" (a probiotic) and inulin (a prebiotic) on the colitis were investigated. The production of NO was evaluated in the supernatants of peritoneal macrophages (pMφ) cultures. Colonic mucosa histology was subsequently examined. Results showed severe acute UC after administration of DSS. High levels of NO in pMφ cultures were also observed compared to control samples. These findings correlated with a significant destruction of the colonic mucosa. Oral administration of Ultrabiotique® or inulin decreased the severity of DSS-induced colitis. These treatments lead to a decrease in NO levels in pMφ cultures. A considerable reduction of colonic lesions was also noticed. Our findings suggest the involvement of NO in experimental UC pathogenesis. Pre- and pro-biotics, as discussed herein, seem to have an anti-inflammatory effect.

The Montreal classification for Crohn's disease: clinical application to a Brazilian single-center cohort of 90 consecutive patients

CONTEXT

Crohn's disease presents very heterogeneous features from a clinical point of view, and classifying Crohn's disease patients in homogeneous subgroups in the light of genetic, molecular and clinical aspects is challenging. The Montreal Classification for Crohn's disease was proposed in 2005 as an effort to characterize Crohn's disease patients according to recent clinical and research advances in the field of inflammatory bowel disease. Since its proposition, the Montreal Classification needs an ample validation and application among different populations around the world. To date, there are no known studies applying the Montreal Classification to a Brazilian cohort of Crohn's disease patients.

OBJECTIVES

To apply the Montreal Classification to a Brazilian cohort of Crohn's disease patients at a referral center for inflammatory bowel disease in Northwestern São Paulo State, Brazil.

METHODS

We selected 90 consecutive well-characterized Crohn's disease patients assisted at Inflammatory Bowel Disease Outpatient Clinic between January 1992 and January 2007, with a minimum follow-up of 2 years; data concerning demographic characteristics, clinical onset of disease, age at diagnosis, time of disease, location and behavior of disease, presence of extraintestinal manifestations, familial occurrence, perianal involvement, treatment with biological drugs, and history of surgical treatment were evaluated.

RESULTS

Male patients were predominant (54%), with a mean age at diagnosis of 33 ± 14 years old, and a median followup of 5.5 years. Most of the patients were diagnosed between 17 and 40 years old (59%), and had disease located in terminal ileum 46%), with a nonstricturing, nonpenetrating behavior (71%). Time of disease was correlated with necessity of biological treatment, disease behavior, and surgical treatment (P<0.05).

CONCLUSIONS

These study findings are consistent with results from other studies conducted among different populations, although a further multicentric study with a larger number of patients would be necessary to validate the Montreal Classification among Brazilian population.

CD14+ cell-derived IL-29 modulates proinflammatory cytokine production in patients with allergic airway inflammation

BACKGROUND

  Interleukin (IL)-29 is a newly described cytokine that has anti-viral activity, induces tumor cell death and regulates immune function. Whether it plays a role in immune disorders is unclear. This study aims to examine the role of IL-29 in the modulation of immune response under allergic environment.

METHODS

  A group of patients with allergic asthma or/and allergic rhinitis was recruited to this study. Serum samples were collected from the patients in both in-season and out-season; the serum levels of IL-29 were determined by enzyme-linked immunoassay. Cell types of IL-29-producing cells in upper airway mucosa were identified with immune staining and examined by immunohistochemistry and flow cytometry.

RESULTS

  High serum levels of IL-29 were detected in patients with allergic asthma in in-season, but not in out-season. The majority of IL-29(+) cells in upper airway tissue were CD14(+) cells. Exposure to specific antigens triggered the release of IL-4 from antigen-specific CD4(+) T cells; the released IL-4 activated CD14(+) cells to release IL-29; the released IL-29 further triggered the release of IL-6 and tumor necrosis factor from CD4(+) T cells.

CONCLUSIONS

  Interleukin-29 is involved in the pathogenesis of allergic inflammation via modulating immune cells' function to release proinflammatory cytokines.

Magnetic resonance imaging of experimental inflammatory bowel disease: quantitative and qualitative analyses with histopathologic correlation in a rat model using the ultrasmall iron oxide SHU 555 C

OBJECTIVES

To quantitatively and qualitatively characterize the MR findings of inflammatory bowel disease in a rat model after i.v. injection of the reticuloendothelial system cell specific ultrasmall iron oxide SHU 555 C.

MATERIALS AND METHODS

Colitis was induced in 15 rats using dinitrobenzene sulfonic acid instillation. Five rats served as controls. T1- and T2-weighted spin-echo- and T2*-weighted gradient-echo-sequences were acquired at 2.4 Tesla before and immediately, 15, 45, 60, and 90 minutes, and 24 hours after i.v.-injection of SHU 555 C (0.1 mmol Fe/kg). MR images were evaluated quantitatively regarding thickness and signal-to-noise ratio (SNR) of the bowel wall and qualitatively regarding overall bowel wall signal intensity and the occurrence of bowel wall ulcerations. MR findings were correlated to histology.

RESULTS

The inflamed bowel wall was significantly thicker than the noninflamed bowel wall and 90 minutes after contrast injection it showed a significant reduction of SNR in T1- (94 +/- 27 vs. 61 +/- 29; P < 0.01), T2- (67 +/- 26 vs. 28 +/- 17; P < 0.05), and T2*- (92 +/- 57 vs. 10 +/- 7; P < 0.05) weighted images as compared with unenhanced images. At 24 hours, the respective SNR values remained significantly reduced. The signal loss was homogeneous in 12 and focal in 3 of the 15 rats with colitis. Nine rats showed colonic wall ulcerations. In all but one animal (missed focal ulceration) MR findings correlated to the histologic findings.

CONCLUSIONS

SHU 555 C leads to a significant signal intensity loss of the inflamed bowel wall in T1-, T2- and T2*-weighted images. SHU 555 C enhanced MRI findings correlate well with histologic findings.

Bacterial-mucosal interactions in inflammatory bowel disease: an alliance gone bad

The complex interaction of genetic, microbial, and environmental factors may result in continuous activation of the mucosal immune system leading to inflammatory bowel disease (IBD). Most present treatments for IBD involve altering or suppressing the aberrant immune response; however, the role of the intestinal microbiota in the pathophysiology of IBD is becoming more evident. The epithelial layer is essential for the proper functioning of the gastrointestinal tract, and its increased permeability to the luminal antigens may lead to the inflammatory processes and mucosal damage observed in IBD. Factors affecting the efficacy of the epithelial barrier include presence of pathogenic bacteria (e.g., Helicobacter spp.), presence of probiotic bacteria, availability of selected nutrients, and others. Defective function of the mucosal barrier might facilitate the contact of bacterial antigens and adjuvants with innate and adaptive immune cells to generate prolonged inflammatory responses. This review will briefly describe the complex structure of the epithelial barrier in the context of bacterial-mucosal interactions observed in human IBD and mouse models of colitis.

Probiotics and prebiotics in inflammatory bowel disease: microflora 'on the scope'

The intestinal microflora is a large bacterial community that colonizes the gut, with a metabolic activity equal to an organ and various functions that affect the physiology and pathology of the host's mucosal immune system. Intestinal bacteria are useful in promotion of human health, but certain components of microflora, in genetically susceptible individuals, contribute to various pathological disorders, including inflammatory bowel disease. Clinical and experimental observations indicate an imbalance in protective and harmful microflora components in these disorders. Manipulation of gut flora to enhance its protective and beneficial role represents a promising field of new therapeutic strategies of inflammatory bowel disease. In this review, we discuss the implication of gut flora in the intestinal inflammation that justifies the role of probiotics and prebiotics in the prevention and treatment of inflammatory bowel disease and we address the evidence for therapeutic benefits from their use in experimental models of colitis and clinical trials.

Advances in studies on relation between inflammatory bowel disease and immunity

Inflammatory bowel disease is a chronic inflammatory disease of the gastrointestinal tract. Its main clinical manifestations are abdominal pain and diarrhea. Its etiology is complicated. Immune system is very important. Following factors, such as intestinal environment, immune cells, human leukocyte antigens, antibodies, anti- laminaribioside antibody, anti-chitobioside antibody IgA, cytokines, cell adhesion molecules, NO and NF-κB, play a key role in the pathogenesis of inflammatory bowel disease. Inflammatory bowel disease is related to all these factors. This paper reviews the possible role of these immune factors in the pathogenesis of inflammatory bowel disease.