Mesalazine in inflammatory bowel disease: a trendy topic once again?

The Multiple Roles of Heat Shock Proteins in the Development of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), a chronic inflammatory condition of the human intestine, comprises Crohn's disease (CD) and ulcerative colitis (UC). IBD causes severe gastrointestinal symptoms and increases the risk of developing colorectal carcinoma. Although the etiology of IBD remains ambiguous, complex interactions between genetic predisposition, microbiota, epithelial barrier, and immune factors have been implicated. The disruption of intestinal homeostasis is a cardinal characteristic of IBD. Patients with IBD exhibit intestinal microbiota dysbiosis, impaired epithelial tight junctions, and immune dysregulation; however, the relationship between them is not completely understood. As the largest body surface is exposed to the external environment, the gastrointestinal tract epithelium is continuously subjected to environmental and endogenous stressors that can disrupt cellular homeostasis and survival. Heat shock proteins (HSPs) are endogenous factors that play crucial roles in various physiological processes, such as maintaining intestinal homeostasis and influencing IBD progression. Specifically, HSPs share an intricate association with microbes, intestinal epithelium, and the immune system. In this review, we aim to elucidate the impact of HSPs on IBD development by examining their involvement in the interactions between the intestinal microbiota, epithelial barrier, and immune system. The recent clinical and animal models and cellular research delineating the relationship between HSPs and IBD are summarized. Additionally, new perspectives on IBD treatment approaches have been proposed.

Cellular Immunology of Myocarditis: Lights and Shades-A Literature Review

Myocarditis is an inflammatory disease of the myocardium with heterogeneous etiology, clinical presentation, and prognosis; when it is associated with myocardial dysfunction, this identifies the entity of inflammatory cardiomyopathy. In the last few decades, the relevance of the immune system in myocarditis onset and progression has become evident, thus having crucial clinical relevance in terms of treatment and prognostic stratification. In fact, the advances in cardiac immunology have led to a better characterization of the cellular subtypes involved in the pathogenesis of inflammatory cardiomyopathy, whether the etiology is infectious or autoimmune/immune-mediated. The difference in the clinical course between spontaneous recovery to acute, subacute, or chronic progression to end-stage heart failure may be explained not only by classical prognostic markers but also through immune-pathological mechanisms at a cellular level. Nevertheless, much still needs to be clarified in terms of immune characterization and molecular mechanisms especially in biopsy-proven myocarditis. The aims of this review are to (1) describe inflammatory cardiomyopathy etiology, especially immune-mediated/autoimmune forms, (2) analyze recent findings on the role of different immune cells subtypes in myocarditis, (3) illustrate the potential clinical relevance of such findings, and (4) highlight the need of further studies in pivotal areas of myocarditis cellular immunology.

Phytochemical Compounds as Promising Therapeutics for Intestinal Fibrosis in Inflammatory Bowel Disease: A Critical Review

BACKGROUND/OBJECTIVE

Intestinal fibrosis, a prominent consequence of inflammatory bowel disease (IBD), presents considerable difficulty owing to the absence of licensed antifibrotic therapies. This review assesses the therapeutic potential of phytochemicals as alternate methods for controlling intestinal fibrosis. Phytochemicals, bioactive molecules originating from plants, exhibit potential antifibrotic, anti-inflammatory, and antioxidant activities, targeting pathways associated with inflammation and fibrosis. Compounds such as Asperuloside, Berberine, and olive phenols have demonstrated potential in preclinical models by regulating critical signaling pathways, including TGF-β/Smad and NFκB, which are integral to advancing fibrosis.

RESULTS

The main findings suggest that these phytochemicals significantly reduce fibrotic markers, collagen deposition, and inflammation in various experimental models of IBD. These phytochemicals may function as supplementary medicines to standard treatments, perhaps enhancing patient outcomes while mitigating the adverse effects of prolonged immunosuppressive usage. Nonetheless, additional clinical trials are necessary to validate their safety, effectiveness, and bioavailability in human subjects.

CONCLUSIONS

Therefore, investigating phytochemicals may lead to crucial advances in the formulation of innovative treatment approaches for fibrosis associated with IBD, offering a promising avenue for future therapeutic development.

Investigating the effects of combined treatment of mesalazine with Lactobacillus casei in the experimental model of ulcerative colitis

Introduction

Ulcerative colitis (UC), a common gastrointestinal disorder in affluent nations, involves chronic intestinal mucosal inflammation. This research investigated the effects of combined probiotic treatment of Lactobacillus casei (L. casei) and mesalazine on disease activity index and inflammatory factors in the UC model.

Methods

20 male BALB/c mice were utilized and divided into four groups. To induce UC, all groups received 100 μL of 4% acetic acid (AA) intra-rectally. The first group received phosphate-buffered saline (PBS) (as a control group), the second group was treated with L. casei, the third group was treated with mesalazine and, the fourth group was treated with L. casei and mesalazine. Treatment with L. Casei and mesalazine commenced after the manifestation of symptoms resulting from UC induction. Finally, the mice were euthanized and the disease activity index, myeloperoxidase activity, nitric oxide rate, cytokines level (IL-1β, IL-6, TNF-α) and, gene expression (iNOS, COX-2, and cytokines) were evaluated.

Results

The combined treatment of L. casei and mesalazine led to a significant decrease in the levels of NO, MPO and inflammatory cytokines. In addition, the expression of cytokines, iNOS and COX-2 genes decreased in mice treated with the combination.

Discussion

This study shows that combined treatment of L. casei and mesalazine improves of experimental UC, which can be attributed to the anti-inflammatory properties of L. casei and mesalazine. In conclusion, this combination therapy can be considered a suitable option for the management of UC.

Current Pharmacologic Options and Emerging Therapeutic Approaches for the Management of Ulcerative Colitis: A Narrative Review

Introduction

Ulcerative colitis (UC) is a chronic inflammatory bowel disorder (IBD) with periods of relapse and remission. Current advancements in clinical research have led to the development of more refined and effective medical therapy for UC.

Summary of the Evidence

Traditional therapeutic agents such as 5-aminosalicylates (5-ASAs), sulfasalazine (SASP), corticosteroids, and immunomodulatory drugs have remained the gold standard for decades. However, their novel formulations and dosage regimens have changed their sequences in the medical management of UC. Several other novel drugs are in the final phases of clinical development or have recently received regulatory approval designed to target specific mechanisms involved in the inflammatory cascade for UC.

Conclusions

This narrative review sought to provide a comprehensive knowledge of the potential benefits of standard and emerging therapies, including novel formulations, new chemical entities, and novel therapeutic approaches in managing UC. Keywords: Ulcerative colitis, 5- Aminosalicylic acid, sulfasalazine, corticosteroids, biologics, immunomodulators, novel formulations.

Bioinspired and bioderived nanomedicine for inflammatory bowel disease

Due to its chronic nature and complex pathophysiology, inflammatory bowel disease (IBD) poses significant challenges for treatment. The long-term therapies for patients, often diagnosed between the ages of 20 and 40, call for innovative strategies to target inflammation, minimize systemic drug exposure, and improve patients' therapeutic outcomes. Among the plethora of strategies currently pursued, bioinspired and bioderived nano-based formulations have garnered interest for their safety and versatility in the management of IBD. Bioinspired nanomedicine can host and deliver not only small drug molecules but also biotherapeutics, be made gastroresistant and mucoadhesive or mucopenetrating and, for these reasons, are largely investigated for oral administration, while surprisingly less for rectal delivery, recommended first-line treatment approach for several IBD patients. The use of bioderived nanocarriers, mostly extracellular vesicles (EVs), endowed with unique homing abilities, is still in its infancy with respect to the arsenal of nanomedicine under investigation for IBD treatment. An emerging source of EVs suited for oral administration is ingesta, that is, plants or milk, thanks to their remarkable ability to resist the harsh environment of the upper gastrointestinal tract. Inspired by the unparalleled properties of natural biomaterials, sophisticated avenues for enhancing therapeutic efficacy and advancing precision medicine approaches in IBD care are taking shape, although bottlenecks arising either from the complexity of the nanomedicine designed or from the lack of a clear regulatory pathway still hinder a smooth and efficient translation to the clinics. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Indigo Naturalis in Inflammatory Bowel Disease: mechanisms of action and insights from clinical trials

This study investigates the therapeutic potential of Indigo Naturalis (IN) in treating a Inflammatory Bowel Disease (IBD). The objective is to comprehensively examine the effects and pharmacological mechanisms of IN on IBD, assessing its potential as an novel treatment for IBD. Analysis of 11 selected papers is conducted to understand the effects of IN, focusing on compounds like indirubin, isatin, indigo, and tryptanthrin. This study evaluates their impact on Disease Activity Index (DAI) score, colon length, mucosal damage, and macrophage infiltration in Dextran Sulfate Sodium (DSS)-induced colitis mice. Additionally, It investigate into the anti-inflammatory mechanisms, including Aryl hydrocarbon Receptor (AhR) pathway activation, Nuclear Factor kappa B (NF-κB)/nod-like receptor family pyrin domain containing 3 (NLRP3)/Interleukin 1 beta (IL-1β) inhibition, and modulation of Toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MYD88)/NF-κB and Mitogen Activated Protein Kinase (MAPK) pathways. Immunomodulatory effects on T helper 17 (Th17)/regulatory T cell (Treg cell) balance and Glycogen synthase kinase-3 beta (GSK3-β) expression are also explored. Furthermore, the study addresses the role of IN in restoring intestinal microbiota diversity, reducing pathogenic bacteria, and increasing beneficial bacteria. The findings reveal that IN, particularly indirubin and indigo, demonstrates significant improvements in DAI score, colon length, mucosal damage, and macrophage infiltration in DSS-induced colitis mice. The anti-inflammatory effects are attributed to the activation of the AhR pathway, inhibition of inflammatory pathways, and modulation of immune responses. These results exhibit the potential of IN in IBD treatment. Notably, the restoration of intestinal microbiota diversity and balance further supports its efficacy. IN emerges as a promising and effective treatment for IBD, demonstrating anti-inflammatory effects and positive outcomes in preclinical studies. However, potential side effects necessitate further investigation for safe therapeutic development. The study underscores the need for future research to explore a broader range of active ingredients in IN to enhance therapeutic efficacy and safety.

Gabapentin attenuates cardiac remodeling after myocardial infarction by inhibiting M1 macrophage polarization through the peroxisome proliferator-activated receptor-γ pathway

OBJECTIVES

Inflammation regulates ventricular remodeling after myocardial infarction (MI), and gabapentin exerts anti-inflammatory effects. We investigated the anti-inflammatory role and mechanism of gabapentin after MI.

METHODS

Rats were divided into the sham group (n = 12), MI group (n = 20), and MI + gabapentin group (n = 16). MI was induced by left coronary artery ligation. The effects of gabapentin on THP-1-derived macrophages were examined in vitro.

RESULTS

In vivo, 1 week after MI, gabapentin significantly reduced inducible nitric oxide synthase (iNOS; M1 macrophage marker) expression and decreased pro-inflammatory factors (tumor necrosis factor [TNF]-α and interleukin [IL]-1β). Gabapentin upregulated the M2 macrophage marker arginase-1, as well as CD163 expression, and increased the expression of anti-inflammatory factors, including chitinase-like 3, IL-10, and transforming growth factor-β. Four weeks after MI, cardiac function, infarct size, and cardiac fibrosis improved after gabapentin treatment. Gabapentin inhibited sympathetic nerve activity and decreased ventricular electrical instability in rats after MI. Tyrosine hydroxylase and growth-associated protein 43 were suppressed after gabapentin treatment. Gabapentin downregulated nerve growth factor (NGF) and reduced pro-inflammatory factors (iNOS, TNF-α, and IL-1β). In vitro, gabapentin reduced NGF, iNOS, TNF-α, and IL-1β expression in lipopolysaccharide-stimulated macrophages. Mechanistic studies revealed that the peroxisome proliferator-activated receptor-γ antagonist GW9662 attenuated the effects of gabapentin. Moreover, gabapentin reduced α2δ1 expression in the macrophage plasma membrane and reduced the calcium content of macrophages.

CONCLUSION

Gabapentin attenuates cardiac remodeling by inhibiting inflammation via peroxisome proliferator-activated receptor-γ activation and preventing calcium overload.

The aminosalicylate - folate connection

Two aminosalicylate isomers have been found to possess useful pharmacological behavior: p-aminosalicylate (PAS, 4AS) is an anti-tubercular agent that targets M. tuberculosis, and 5-aminosalicylate (5AS, mesalamine, mesalazine) is used in the treatment of ulcerative colitis (UC) and other inflammatory bowel diseases (IBD). PAS, a structural analog of pABA, is biosynthetically incorporated by bacterial dihydropteroate synthase (DHPS), ultimately yielding a dihydrofolate (DHF) analog containing an additional hydroxyl group in the pABA ring: 2'-hydroxy-7,8-dihydrofolate. It has been reported to perturb folate metabolism in M. tuberculosis, and to selectively target M. tuberculosis dihydrofolate reductase (mtDHFR). Studies of PAS metabolism are reviewed, and possible mechanisms for its mtDHFR inhibition are considered. Although 5AS is a more distant structural relative of pABA, multiple lines of evidence suggest a related role as a pABA antagonist that inhibits bacterial folate biosynthesis. Structural data support the likelihood that 5AS is recognized by the DHPS pABA binding site, and its effects probably range from blocking pABA binding to formation of a dead-end dihydropterin-5AS adduct. These studies suggest that mesalamine acts as a gut bacteria-directed antifolate, that selectively targets faster growing, more folate-dependent species.

New genetic biomarkers predicting 5-aminosalicylate-induced adverse events in patients with inflammatory bowel diseases

Background

Notably, 5-aminosalicylates (5-ASA) are vital in treating inflammatory bowel diseases (IBD). The adverse events of 5-ASA rarely occur but they could be fatal.

Objectives

We aimed to discover new genetic biomarkers predicting 5-ASA-induced adverse events in patients with IBD.

Design

This was a retrospective observational study.

Methods

We performed a genome-wide association study on patients with IBD in South Korea. We defined subset 1 as 39 all adverse events and 272 controls; subset 2 as 20 severe adverse events and 291 controls (mild adverse events and control); subset 3 as 20 severe adverse events and 272 controls; and subset 4 as 19 mild adverse events and 272 controls. Logistic regression analysis was performed and commonly found associated genes were determined as candidate single-nucleotide polymorphisms predicting 5-ASA adverse events.

Results

Patients with Crohn's disease (CD) were significantly negatively associated with the development of adverse events compared to patients with ulcerative colitis (UC) (5.3% versus 22.9%). However, sex and age at diagnosis were unassociated with the adverse events of 5-ASA. rs13898676 [odds ratio (OR), 20.33; 95% confidence interval (CI), 5.69-72.67; p = 3.57 × e-6], rs12681590 (OR, 7.35; 95% CI, 2.85-19.00; p = 3.78 × e-5), rs10967320 (OR, 4.51; 95% CI, 2.18-9.31; p = 4.72 × e-5), and rs78726924 (OR, 3.54; 95% CI, 1.69-7.40; p = 7.96 × e-5) were genetic biomarkers predicting 5-ASA-induced severe adverse events in patients with IBD.

Conclusion

The adverse events of 5-ASA were more common in patients with UC than those with CD in our study. We found that novel rs13898676 nearby WSB2 was the most significant genetic locus contributing to 5-ASA's adverse event risk.

Crohn's disease: An enigmatic variant with gastritis and ileal obstruction

There are multiple atypical manifestations of Crohn's disease, which sometimes delay diagnosis or even more often result in complete misdiagnosis, especially in poorly equipped facilities. This is the case of an elderly woman with Crohn's disease who presented with gastritis and bowel obstruction. She had hitherto been wrongly managed for peptic ulcer disease and functional constipation based mainly on her symptoms. Her diagnosis was made only after years of failed symptomatic management. This case aims to highlight the uncommon and easily misdiagnosed gastroduodenal presentation of Crohn's disease, as well as clinical clues to correctly diagnosing the condition.

Oxidative Coupling Assay for Mesalazine Determination in Pharmaceuticals and Spiked Human Plasma Utilizing Syringic Acid

This study reports on developing a simple, cost-effective, highly sensitive spectrophotometric method for measuring mesalazine (MSZ). The method utilizes the oxidative coupling of MSZ with syringic acid (4-hydroxy 3,5-dimethoxybenzoic acid) in the presence of dissolved oxygen under alkaline conditions to form a stable indophenol dye with a characteristic blue color, which can be measured at 615 nm. Beer’s law was found to be obeyed over the range of 1.25–50 µg·mL−1, with a molar absorptivity of 0.53 × 104 mol−1·L−1·cm−1. Moreover, the method exhibited excellent sensitivity, with a limit of detection (LOD) of 0.093 µg·mL−1 and a limit of quantitation (LOQ) of 0.282 µg·mL−1. The proposed method was found to be selective, as it could effectively detect MSZ in the presence of certain interfering species. The proposed method was validated according to current ICH guidelines and demonstrated good accuracy, with recoveries ranging between 98 and 100% and a relative standard deviation of less than 0.6%. Overall, this method provides a promising tool for the sensitive and accurate determination of MSZ in its pure form, pharmaceutical formulations, and biological samples.

Risk of Hemolytic Anemia in IBD Patients with Glucose-6-Phosphate Dehydrogenase Deficiency Treated with Mesalamine: Results of a Retrospective-Prospective and Ex Vivo Study

BACKGROUND

Mesalamine is one of the most-used drugs in inflammatory bowel disease (IBD), especially ulcerative colitis. Regulatory agencies have listed mesalamine as an unsafe drug in subjects with glucose-6-phosphate dehydrogenase (G6PD) deficiency based on the risk of hemolysis, although scientific evidence is lacking. The occurrence of acute and/or chronic hemolytic anemia in IBD patients with G6PD deficiency exposed to mesalamine was evaluated.

METHODS

In this multicenter study, IBD patients with G6PD deficiency (cases) receiving mesalamine were retrospectively evaluated for acute, and prospectively for chronic, hemolysis. The presence of hemolytic anemia was based on red blood cell and reticulocyte count, hemoglobin, lactate dehydrogenase, unconjugated bilirubin, and haptoglobin levels. Cases were compared with controls (IBD patients with normal G6PD).

RESULTS

A total of 453 IBD patients (mean age 52.1 ± 16.0 years; 58.5% female) were enrolled. Ulcerative colitis was present in 75% of patients. G6PD deficiency was detected in 17% of patients. Oral mesalamine was used in 67.9% of ulcerative colitis and in 32.4% of Crohn's disease cases. None of the 78 IBD patients with G6PD deficiency receiving mesalamine underwent hospitalization or specific treatment for acute hemolytic anemia. Relevant differences in chronic hemolysis markers were not observed in 30 cases compared with 112 controls receiving mesalamine (≤4500 mg/day). Marker modifications were also observed in mesalamine-free cases, consistent with the basal rate of erythrophagocytosis in G6PD deficiency. Ex vivo experiments showed the release of methemoglobin by G6PD deficient RBCs upon mesalamine challenge, only above 2.5 mg/mL, a concentration never reached in the clinical setting.

CONCLUSIONS

This study provides, for the first time, evidence that mesalamine is safe in G6PD deficiency at a dosage of up to 4500 mg/day.

Myocarditis Related to the Use of Mesalazine

Myocarditis is a rare complication of therapy with mesalazine, a drug traditionally used in the treatment of inflammatory bowel disease. We report a case of a 32-year-old man with a recent diagnosis of ulcerative colitis, who presented to our hospital with chest pain and elevated troponin, 12 days following initiation of mesalazine. Diagnosis of myocarditis was confirmed with cardiac magnetic resonance imaging (CMR), which showed subepicardial gadolinium enhancement in the basal lateral/inferolateral segment of the heart. The patient's clinical condition improved upon stopping mesalazine and the follow-up CMR demonstrated resolution of the previous findings. Mesalazine can cause myocarditis early after initiation and clinicians should be aware of this rare yet serious cardiotoxic effect, as the discontinuation of the medication is the mainstay of treatment and leads to significant recovery.

Molecular Mechanisms of the Antitumor Effects of Mesalazine and Its Preventive Potential in Colorectal Cancer

Chemoprevention is one of the ways to fight colorectal cancer, which is a huge challenge in oncology. Numerous pieces of evidence indicate that chronic inflammation in the course of Crohn's disease or ulcerative colitis (UC) is a significant cancer risk factor. Epidemiologic studies suggest that long-term use of non-steroidal anti-inflammatory drugs (NSAIDs), including mesalazine, has beneficial effects on colitis-associated colorectal cancer. Mesalazine is a first-line therapy for UC and is also widely used for maintaining remission in UC. Data showed that mesalazine has antiproliferative properties associated with cyclooxygenase (COX) inhibition but can also act through COX-independent pathways. This review summarizes knowledge about mesalazine's molecular mechanisms of action and chemopreventive effect by which it could interfere with colorectal cancer cell proliferation and survival.

COVID-19 susceptibility and clinical outcomes in inflammatory bowel disease: An updated systematic review and meta-analysis

The susceptibility, risk factors, and prognosis of COVID-19 in patients with inflammatory bowel disease (IBD) remain unknown. Thus, our study aims to assess the prevalence and clinical outcomes of COVID-19 in IBD. We searched PubMed, EMBASE, and medRxiv from 2019 to 1 June 2022 for cohort and case-control studies comparing the prevalence and clinical outcomes of COVID-19 in patients with IBD and in the general population. We also compared the outcomes of patients receiving and not receiving 5-aminosalicylates (ASA), tumour necrosis factor antagonists, biologics, systemic corticosteroids, or immunomodulators for IBD. Thirty five studies were eligible for our analysis. Pooled odds ratio of COVID-19-related hospitalisation, intensive care unit (ICU) admission, or death in IBD compared to in non-IBD were 0.58 (95% confidence interval (CI) = 0.28-1.18), 1.09 (95% CI = 0.27-4.47), and 0.67 (95% CI = 0.32-1.42), respectively. Inflammatory bowel disease was not associated with increased hospitalisation, ICU admission, or death. Susceptibility to COVID-19 did not increase with any drugs for IBD. Hospitalisation, ICU admission, and death were more likely with 5-ASA and corticosteroid use. COVID-19-related hospitalisation (Odds Ratio (OR): 0.53; 95% CI = 0.38-0.74) and death (OR: 0.13; 95% CI = 0.13-0.70) were less likely with Crohn's disease than ulcerative colitis (UC). In conclusion, IBD does not increase the mortality and morbidity of COVID-19. However, physicians should be aware that additional monitoring is needed in UC patients or in patients taking 5-ASA or systemic corticosteroids.

Current evidence and clinical relevance of drug-microbiota interactions in inflammatory bowel disease

Background

Inflammatory bowel disease (IBD) is a chronic relapsing-remitting disease. An adverse immune reaction toward the intestinal microbiota is involved in the pathophysiology and microbial perturbations are associated with IBD in general and with flares specifically. Although medical drugs are the cornerstone of current treatment, responses vary widely between patients and drugs. The intestinal microbiota can metabolize medical drugs, which may influence IBD drug (non-)response and side effects. Conversely, several drugs can impact the intestinal microbiota and thereby host effects. This review provides a comprehensive overview of current evidence on bidirectional interactions between the microbiota and relevant IBD drugs (pharmacomicrobiomics).

Methods

Electronic literature searches were conducted in PubMed, Web of Science and Cochrane databases to identify relevant publications. Studies reporting on microbiota composition and/or drug metabolism were included.

Results

The intestinal microbiota can both enzymatically activate IBD pro-drugs (e.g., in case of thiopurines), but also inactivate certain drugs (e.g., mesalazine by acetylation via N-acetyltransferase 1 and infliximab via IgG-degrading enzymes). Aminosalicylates, corticosteroids, thiopurines, calcineurin inhibitors, anti-tumor necrosis factor biologicals and tofacitinib were all reported to alter the intestinal microbiota composition, including changes in microbial diversity and/or relative abundances of various microbial taxa.

Conclusion

Various lines of evidence have shown the ability of the intestinal microbiota to interfere with IBD drugs and vice versa. These interactions can influence treatment response, but well-designed clinical studies and combined in vivo and ex vivo models are needed to achieve consistent findings and evaluate clinical relevance.

Landscape of new drugs and targets in inflammatory bowel disease

Although the therapeutic armamentarium of Inflammatory bowel diseases (IBD) physicians has expanded rapidly in recent years, a proportion of patients remain with a suboptimal response to medical treatment due to primary no response, loss of response or intolerance to currently available drugs. Our growing knowledges of IBD pathophysiology has led to the development of a multitude of new therapies over time, which may, 1 day, be able to address this unmet medical need. This review aims to provide physicians an update of emerging therapies in IBD by focusing on drugs currently in phase 3 clinical trials. Among the most promising molecules are anti-IL-23, JAK-inhibitors, anti-integrins and S1P modulators. While the results in terms of efficacy and safety are fairly clear for some classes, the question of safety remains more uncertain for other classes. Molecules at a more preliminary stage of development (phase 1 and 2), one of which may 1 day offer an optimal benefit-risk ratio, will also be presented as well as their respective mechanisms of action.

Novel Nanostructured Lipid Carriers Co-Loaded with Mesalamine and Curcumin: Formulation, Optimization and In Vitro Evaluation

PURPOSE

The aim of current study is to formulate, optimize and characterize the developed formulation of Mesalamine-Curcumin Nanostructured Lipid Carriers (Mes-Cur NLCs).

METHODS

It was formulated using high pressure homogenization followed by probe sonication and formulation variables were optimized using Central Composite Design. The particle size (PS), zeta potential (ZP), entrapment efficiency (EE), drug release, cytotoxicity on NIH 3T3 fibroblasts cells and HaCaT keratinocytes cells and efficacy on RAW264.7 cells for optimized formulation was determined.

RESULTS

The PS, ZP and EE were found to be 85.26 nm, -23.7 ± 7.45 mV, 99.2 ± 2.62 % (Mes) and 84 ± 1.51 % (Cur), respectively. The good correlation between predicted and obtained value indicated suitability and reproducibility of experimental design. NLCs showed spherical shape as confirmed by TEM. In vitro drug release profile of prepared formulation showed that Mes exhibited 100 % release at 48 h, whereas Cur exhibited 82.23 ± 2.97% release at 120 h. Both the drugs exhibited sustained release upon incorporation into the NLCs. The absence of any significant cell death during MTT assay performed on NIH 3T3 fibroblasts cells and HaCaT keratinocytes cells indicated that NLCs' were safe for use. Furthermore, significant reduction in nitric oxide level during anti-inflammatory evaluation of formulation on RAW264.7 cells showed excellent potential for the formulation to treat inflammation. The formulation was found stable as no significant difference between the PS, ZP and EE of the fresh and aged NLCs was observed.

CONCLUSION

The outcomes of study deciphered successful formulation of Mes-Cur NLCs.

Response to Mesalamine Therapy in Pediatric Collagenous Gastritis and Colitis: A Case Report and Review

Collagenous gastritis and collagenous colitis are 2 rare gastrointestinal disorders in pediatric patients. Both of these disease processes exist on a clinical spectrum, and are extremely rare to be present together in the pediatric population. Due to the rarity and unknown etiology of these disease processes, standardized treatment protocols and objective clinical biomarkers of disease progression are missing. This is the first report to describe a 16 year old female with CG and CC who responded well to mesalamine therapy, evident by decreasing calprotectin levels after initiation of therapy.

An Update on Current Pharmacotherapeutic Options for the Treatment of Ulcerative Colitis

The main goals of Ulcerative Colitis (UC) treatment are to both induce and maintain the clinical and endoscopic remission of disease, reduce the incidence of complications such as dysplasia and colorectal carcinoma and improve quality of life. Although a curative medical treatment for UC has not yet been found, new therapeutic strategies addressing specific pathogenetic mechanisms of disease are emerging. Notwithstanding these novel therapies, non-biological conventional drugs remain a mainstay of treatment. The aim of this review is to summarize current therapeutic strategies used as treatment for ulcerative colitis and to briefly focus on emerging therapeutic strategies, including novel biologic therapies and small molecules. To date, multiple therapeutic approaches can be adopted in UC and the range of available compounds is constantly increasing. In this era, the realization of well-designed comparative clinical trials, as well as the definition of specific therapeutic models, would be strongly suggested in order to achieve personalized management for UC patients.

Dapsone Azo-Linked with Two Mesalazine Moieties Is a "Me-Better" Alternative to Sulfasalazine

Dapsone (DpS) is an antimicrobial and antiprotozoal agent, especially used to treat leprosy. The drug shares a similar mode of action with sulfonamides. Additionally, it possesses anti-inflammatory activity, useful for treating autoimmune diseases. Here, we developed a “me-better” alternative to sulfasalazine (SSZ), a colon-specific prodrug of mesalazine (5-ASA) used as an anti-inflammatory bowel diseases drug; DpS azo-linked with two molecules of 5-ASA (AS-DpS-AS) was designed and synthesized, and its colon specificity and anti-colitic activity were evaluated. AS-DpS-AS was converted to DpS and the two molecules of 5-ASA (up to approximately 87% conversion) within 24 h after incubation in the cecal contents. Compared to SSZ, AS-DpS-AS showed greater efficiency in colonic drug delivery following oral gavage. Simultaneously, AS-DpS-AS substantially limited the systemic absorption of DpS. In a dinitrobenzene sulfonic acid-induced rat colitis model, oral AS-DpS-AS elicited better efficacy against rat colitis than oral SSZ. Moreover, intracolonic treatment with DpS and/or 5-ASA clearly showed that combined treatment with DpS and 5-ASA was more effective against rat colitis than the single treatment with either DpS or 5-ASA. These results suggest that AS-DpS-AS may be a “me-better” drug of SSZ with higher therapeutic efficacy, owing to the combined anti-colitic effects of 5-ASA and DpS.

The Molecular Mechanisms of Intestinal Inflammation and Fibrosis in Crohn’s Disease

Crohn’s disease (CD) is an inflammatory bowel disease (IBD) with repeated remissions and relapses. As the disease progresses, fibrosis and narrowing of the intestine occur, leading to severe complications such as intestinal obstruction. Endoscopic balloon dilatation, surgical stricture plasty, and bowel resection have been performed to treat intestinal stenosis. The clinical issue is that some patients with CD have a recurrence of intestinal stenosis even after the medical treatments. On the other hand, there exist no established medical therapies to prevent stenosis. With the progressive intestinal inflammation, cytokines and growth factors, including transforming growth factor (TGF-β), stimulate intestinal myofibroblasts, contributing to fibrosis of the intestine, smooth muscle hypertrophy, and mesenteric fat hypertrophy. Therefore, chronically sustained inflammation has long been considered a cause of intestinal fibrosis and stenosis. Still, even after the advent of biologics and tighter control of inflammation, intestinal fibrosis’s surgical rate has not necessarily decreased. It is essential to elucidate the mechanisms involved in intestinal fibrosis in CD from a molecular biological level to overcome clinical issues. Recently, much attention has been paid to several key molecules of intestinal fibrosis: peroxisome proliferator-activating receptor gamma (PPARγ), toll-like receptor 4 (TLR4), adherent-invasive Escherichia coli (AIEC), Th17 immune response, and plasminogen activator inhibitor 1 (PAI-1). As a major problem in the treatment of CD, the pathophysiology of patients with CD is not the same and varies depending on each patient. It is necessary to integrate these key molecules for a better understanding of the mechanism of intestinal inflammation and fibrosis.

Chemoprevention with a tea from hawthorn (Crataegus oxyacantha) leaves and flowers attenuates colitis in rats by reducing inflammation and oxidative stress

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A tea from the leaves and flowers of hawthorn is rich in flavonoids, especially vitexin-2-O-rhamnoside.

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Mesalamine and hawthorn tea have positive healing effects in rats with colitis.

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Hawthorn tea reduces the length and area of the brownish necrotic lesions.

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Hawthorn tea diminishes the levels of the inflammatory markers MPO and IL-1β.

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Hawthorn tea regulates the activity of the oxidative stress enzymes CAT and GR.

The purpose of the study was to determine the effects of a tea from the leaves and flowers of Crataegus oxyacantha in rats with colitis. Colitis was induced by administration of 2,4,6-trinitrobenzene sulfonic acid. Hawthorn tea (HT) (100 mg/kg) was given via gavage for 21 days and the mesalamine drug (100 mg/kg) was administrated during the period of disease onset. HT was rich in total phenolic compounds (16.5%), flavonoids (1.8%), and proanthocyanidins (1.5%); vitexin-2-O-rhamnoside was the main compound detected. Mesalamine and the HT diminished the length of the lesions formed in the colon, in addition to reducing the levels of myeloperoxidase and interleukin-1β. Mesalamine was able to significantly reverse the body weight loss, while HT improved the activity of glutathione reductase and catalase. Histological scoring was not changed by the interventions, but it was highly correlated with the necrotic area. HT given at 100 mg/kg can be effective against colitis.

Budding Multi-matrix Technology-a Retrospective Approach, Deep Insights, and Future Perspectives

The human race is consistently striving for achieving good health and eliminate disease-causing factors. For the last few decades, scientists have been endeavoring to invent and innovate technologies that can substitute the conventional dosage forms and enable targeted and prolonged drug release at a particular site. The novel multi-matrix technology is a type of matrix formulation where the formulation is embraced to have a matrix system with multiple number of matrices. The MMX technology embraces with a combination of outer hydrophilic layer and amphiphilic/lipophilic core layer, within which drug is encapsulated followed by enteric coating for extended/targeted release at the required site. In comparison to conventional oral drug delivery systems and other drug delivery systems, multi-matrix (MMX) technology formulations afford many advantages. Additionally, it attributes for targeting strategy aimed at the colon and offers modified prolonged drug release. Thus, it has emerged rapidly as a potential alternative option in targeted oral drug delivery. However, the development of this MMX technology formulations is a exigent task and also has its own set of limitations. Due to its promising advantages and colon targeting strategy over the other colon targeted drug delivery systems, premier global companies are exploiting its potential. This article review deep insights into the formulation procedures, drug delivery mechanism, advantages, limitations, safety and efficacy studies of various marketed drug formulations of MMX technology including regulatory perspectives and future perspectives.

Recommendations for the optimal use of mesalazine in the management of patients with mild to moderate ulcerative colitis

The 2021 National report from IBD UK included responses from over 10 000 patients with inflammatory bowel disease, over 70% of whom reported having at least one flare in the last 12 months. As the first-line treatment for patients with mild and moderate ulcerative colitis, the action and delivery mechanisms of mesalazine are crucial for successful management of the disease. The choice of the most appropriate formulation of mesalazine and securing patient concordance and adherence to treatment remains a challenge for healthcare professionals. This article details the outcome of a roundtable discussion involving a group of gastroenterology consultants and specialist nurses which considered the importance of ensuring that patients have individualised mesalazine therapy before escalation to other treatments and gives recommendations for the management of patients with mild or moderate ulcerative colitis.

Modelling and Simulation of the Drug Release from a Solid Dosage Form in the Human Ascending Colon: The Influence of Different Motility Patterns and Fluid Viscosities

For colonic drug delivery, the ascending part of the colon is the most favourable site as it offers the most suitable environmental conditions for drug dissolution. Commonly, the performance of a drug formulation is assessed using standardised dissolution apparatus, which does not replicate the hydrodynamics and shear stress evoked by wall motion in the colon. In this work, computer simulations are used to analyse and understand the influence of different biorelevant motility patterns on the disintegration/drug release of a solid dosage form (tablet) under different fluid conditions (viscosities) to mimic the ascending colonic environment. Furthermore, the ability of the motility pattern to distribute the drug in the ascending colon luminal environment is analysed to provide data for a spatiotemporal concentration profile. The motility patterns used are derived from in vivo data representing different motility patterns in the human ascending colon. The applied motility patterns show considerable differences in the drug release rate from the tablet, as well as in the ability to distribute the drug along the colon. The drug dissolution/disintegration process from a solid dosage form is primarily influenced by the hydrodynamic and shear stress it experiences, i.e., a combination of motility pattern and fluid viscosity. Reduced fluid motion leads to a more pronounced influence of diffusion in the tablet dissolution process. The motility pattern that provoked frequent single shear stress peaks seemed to be more effective in achieving a higher drug release rate. The ability to simulate drug release profiles under biorelevant colonic environmental conditions provides valuable feedback to better understand the drug formulation and how this can be optimised to ensure that the drug is present in the desired concentration within the ascending colon.

5-Aminolevulinic Acid as a Novel Therapeutic for Inflammatory Bowel Disease

5-Aminolevulinic acid (5-ALA) is a naturally occurring nonprotein amino acid licensed as an optical imaging agent for the treatment of gliomas. In recent years, 5-ALA has been shown to possess anti-inflammatory and immunoregulatory properties through upregulation of heme oxygenase-1 via enhancement of porphyrin, indicating that it may be beneficial for the treatment of inflammatory conditions. This study systematically examines 5-ALA for use in inflammatory bowel disease (IBD). Firstly, the ex vivo colonic stability and permeability of 5-ALA was assessed using human and mouse fluid and tissue. Secondly, the in vivo efficacy of 5-ALA, in the presence of sodium ferrous citrate, was investigated via the oral and intracolonic route in an acute DSS colitis mouse model of IBD. Results showed that 5-ALA was stable in mouse and human colon fluid, as well as in colon tissue. 5-ALA showed more tissue restricted pharmacokinetics when exposed to human colonic tissue. In vivo dosing demonstrated significantly improved colonic inflammation, increased local heme oxygenase-1 levels, and decreased concentrations of proinflammatory cytokines TNF-α, IL-6, and IL-1β in both plasma and colonic tissue. These effects were superior to that measured concurrently with established anti-inflammatory treatments, ciclosporin and 5-aminosalicylic acid (mesalazine). As such, 5-ALA represents a promising addition to the IBD armamentarium, with potential for targeted colonic delivery.

Synthesis and activity of N-(5-hydroxy-3,4,6-trimethylpyridin-2-yl)acetamide analogues as anticolitis agents via dual inhibition of TNF-α- and IL-6-induced cell adhesions

Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) are the critical pro-inflammatory cytokines involved in the pathogenesis of inflammatory bowel disease (IBD). Inhibition of these cytokines and related signaling pathways has been a target for the development of IBD therapeutics. In the current study, 6-acetamido-2,4,5-trimethylpyridin-3-ol (1) and various analogues with the amido scaffold were synthesized and examined for their inhibitory activities in in vitro and in vivo IBD models. The parent compound 1 (1 μM) showed an inhibitory activity against TNF-α- and IL-6-induced adhesion of monocytes to colon epithelial cells, which was similar to tofacitinib (1 μM), a JAK inhibitor, but much better than mesalazine (1,000 μM). All the analogues showed a positive relationship (R² = 0.8943 in a linear regression model) between the inhibitory activities against TNF-α-induced and those against IL-6-induced adhesion. Compound 2-19 turned out to be the best analogue and showed much better inhibitory activity against TNF-α- and IL-6-induced adhesion of the cells than tofacitinib. In addition, oral administration of compound 1 and 2-19 resulted in a significant suppression of clinical signs of TNBS-induced rat colitis, including weight loss, colon tissue edema, and myeloperoxidase activity, a marker for inflammatory cell infiltration in colon tissues. More importantly, compound 2-19 (1 mg/kg) was more efficacious in ameliorating colitis than compound 1 and sulfasalazine (300 mg/kg), the commonly prescribed oral IBD drug. Taken together, the results suggest that compound 2-19 can be a novel platform for dual-acting IBD drug discovery targeting both TNF-α and IL-6 signaling.

circRNA expression profiling of colon tissue from mesalazine-treated mouse of inflammatory bowel disease reveals an important circRNA-miRNA-mRNA pathway

Mesalazine (5-aminosalicylic acid, 5-ASA) has been widely used to treat inflammatory bowel disease (IBD). However, it remains unclear about the underlying biological mechanisms of IBD pathogenesis and mesalazine treatment, which could be partially clarified by exploring the profiling of circular RNAs (circRNAs) using RNA-seq. A total of 15 mice (C57BL/6) were randomly assigned to three equally sized groups: control, dextran sulfate sodium (DSS, using DSS to induce IBD), and DSS+5-ASA (using mesalazine to treat IBD). We randomly selected three mice of each group to collect colon tissues for RNA-seq and then performed bioinformatic analysis for two comparisons: DSS vs. control and DSS+5-ASA vs. DSS. Comparisons of a series of indicators (e.g., body weight) verified the establishment of DSS-induced IBD mouse model and the effectiveness of mesalazine in treating IBD. We identified 182 differentially expressed circRNAs, including 55 up-regulated and 47 down-regulated circRNAs when comparing the DSS+5-ASA with the DSS group. These 102 circRNA-associated genes were significantly involved in the N-Glycan biosynthesis and lysine degradation. The network analysis of circRNA-miRNA-mRNAs identified an important pathway, i.e., chr10:115386962-115390436+/mmu-miR-6914-5p/Atg7, which is related to autophagy. The findings provide new insights into the biological mechanisms of IBD pathogenesis and mesalazine treatment, particularly highlighting the circRNA-miRNA-mRNA pathway.

Treatments of inflammatory bowel disease toward personalized medicine

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a chronic inflammatory disease characterized by intestinal inflammation and epithelial injury. For the treatment of IBD, 5-aminosalicylic acids, corticosteroids, immunomodulators, and biologic agents targeting tumor necrosis factor (TNF)-α, α4β7-integrin, and interleukin (IL)-12/23 have been widely used. Especially, anti-TNF-α antibodies are the first biologic agents that presently remain at the forefront. However, 10-30% of patients resist biologic agents, including anti-TNF-α agents (primary non-responder; PNR), and 20-50% of primary responders develop treatment resistance within one year (secondary loss of response; SLR). Nonetheless, the etiologies of PNR and SLR are not clearly understood, and predictors of response to biologic agents are also not defined yet. Numerous studies are being performed to discover prediction markers of the response to biologic agents, and this review will introduce currently available therapeutic options for IBD, biologics under investigation, and recent studies exploring various predictive factors related to PNR and SLR.

Ni-Doped ZrO2 nanoparticles decorated MW-CNT nanocomposite for the highly sensitive electrochemical detection of 5-amino salicylic acid

Ni-ZrO₂/MWCNT/GCE for highly sensitive electrochemical detection of 5-ASA in biofluids.

Comparative transcriptome analysis of SARS-CoV, MERS-CoV, and SARS-CoV-2 to identify potential pathways for drug repurposing

The ongoing COVID-19 pandemic caused by the coronavirus, SARS-CoV-2, has already caused in excess of 1.25 million deaths worldwide, and the number is increasing. Knowledge of the host transcriptional response against this virus and how the pathways are activated or suppressed compared to other human coronaviruses (SARS-CoV, MERS-CoV) that caused outbreaks previously can help in the identification of potential drugs for the treatment of COVID-19. Hence, we used time point meta-analysis to investigate available SARS-CoV and MERS-CoV in-vitro transcriptome datasets in order to identify the significant genes and pathways that are dysregulated at each time point. The subsequent over-representation analysis (ORA) revealed that several pathways are significantly dysregulated at each time point after both SARS-CoV and MERS-CoV infection. We also performed gene set enrichment analyses of SARS-CoV and MERS-CoV with that of SARS-CoV-2 at the same time point and cell line, the results of which revealed that common pathways are activated and suppressed in all three coronaviruses. Furthermore, an analysis of an in-vivo transcriptomic dataset of COVID-19 patients showed that similar pathways are enriched to those identified in the earlier analyses. Based on these findings, a drug repurposing analysis was performed to identify potential drug candidates for combating COVID-19.

Bipolymeric Pectin Millibeads Doped with Functional Polymers as Matrices for the Controlled and Targeted Release of Mesalazine

Targeted drug delivery systems are a very convenient method of treating inflammatory bowel disease. The properties of pectin make this biopolymer a suitable drug carrier. These properties allow pectin to overcome the diverse environment of the digestive tract and deliver the drug to the large intestine. This investigation proposed bipolymeric formulations consisting of the natural polymer pectin and a synthetic polymer containing the drug 5-aminosalicylic acid. Pectin beads were prepared via ionotropic gelation involving the interaction between the hydrophilic gel and calcium ions. The obtained formulations consisted of natural polymer, 5-aminosalicylic acid (5-ASA) and one of the synthetic polymers, such as polyacrylic acid, polyvinylpyrrolidone, polyethylene glycol or aristoflex. The release of the drug was carried out employing a basket apparatus (USP 1). The acceptor fluid was pH = 7.4 buffer with added enzyme pectinase to reflect the colon environment. The amount of the released drug was determined using UV-Vis spectrophotometry at a wavelength of λ = 330 nm. The kinetics of the drug dissolution revealed that none of the employed models was appropriate to describe the release process. A kinetic analysis of the release profile during two release stages was carried out. The fastest drug release occurred during the first stage from a formulation containing pectin and polyethylene glycol. However, according to the applied kinetic models, the dissolution of 5-ASA was rather high in the formulation without the synthetic polymer during the second stage. Depending on the formulation, 68-77% of 5-ASA was released in an 8-hour time period. The FTIR and DSC results showed that there was no interaction between the drug and the polymers, but interactions between pectin and synthetic polymers were found.

Colitis-targeted hybrid nanoparticles-in-microparticles system for the treatment of ulcerative colitis

Nanoparticle (NP)-based drug delivery systems accumulate in the disrupted epithelium of inflamed colon tissue in ulcerative colitis. However, premature early drug release and uptake or degradation of NPs during their passage through the harsh gastric or intestinal environment compromise their therapeutic outcomes. This study aimed to develop an advanced colitis-targeted hybrid nanoparticles-in-microparticles (NPsinMPs) drug delivery system to overcome the aforementioned challenges. First, sustained drug releasing poly(lactic-co-glycolic acid) NPs were generated and further encapsulated in pH-sensitive Eudragit FS30D MPs to ensure complete drug protection in a gastric-like pH and for selective delivery of NPs to the colon. SEM and confocal microscopy for the NPsinMPs revealed successful NP encapsulation. NPsinMPs prevented drug release in an acidic gastric-like and intestinal-like pH and presented a sustained release thereafter at an ileal and colonic pH, indicating the degradation of the outer pH-sensitive MPs and release of NPs. Furthermore, in vivo imaging of gastrointestinal tract of a colitis mouse orally administered with fluorescent NPsinMPs revealed higher fluorescence intensities selectively in the colon, demonstrating the release of loaded NPs and their concomitant accumulation at the site of colon inflammation. NPsinMPs markedly mitigated experimental colitis in mice indicated by improved histopathological analysis, decreased myeloperoxidase activity, neutrophils and macrophage infiltration, and expression of proinflammatory cytokines in colonic tissues compared with NP-treated mice. The present results show the successful formulation of an NPsinMP-based drug delivery system and provide a platform to improve NP-based colon-targeted drug delivery through improved protection of encapsulated NPs and their payload in the early small intestine.

Phospholipid Cyclosporine Prodrugs Targeted at Inflammatory Bowel Disease (IBD) Treatment: Design, Synthesis, and in Vitro Validation

Novel phospholipid (PL)-cyclosporine conjugates were prepared and studied as potential prodrugs for inflammatory bowel disease (IBD). Our approach relies on phospholipase A₂ (PLA₂ ), which is overexpressed in the inflamed intestinal tissues, as the prodrug activator to potentially release cyclosporine at the site of inflammation. PL-cyclosporine prodrug conjugates with methylene linkers of various lengths between the sn-2 position of the PL and cyclosporine were synthesized and evaluated for in vitro activation. Surprisingly, despite previous work indicating that conjugates with six methylene linkers between the lipid and drug would suffer rapid enzymatic hydrolysis, with cyclosporine this was not observed. However, compounds with longer linkers (n=10, 12 methylene units) display complete release of the drug by PLA₂ -catalyzed hydrolysis, thus demonstrating the importance and profound impact of structural fine-tuning. This study represents a proof-of-concept for our hypothesis and a first step towards a truly targeted IBD treatment with cyclosporine that could be administered throughout the GI tract.

Revisiting Inflammatory Bowel Disease: Pathology, Treatments, Challenges and Emerging Therapeutics Including Drug Leads from Natural Products

Inflammatory bowel disease (IBD) is a chronic and life-long disease characterized by gastrointestinal tract inflammation. It is caused by the interplay of the host's genetic predisposition and immune responses, and various environmental factors. Despite many treatment options, there is no cure for IBD. The increasing incidence and prevalence of IBD and lack of effective long-term treatment options have resulted in a substantial economic burden to the healthcare system worldwide. Biologics targeting inflammatory cytokines initiated a shift from symptomatic control towards objective treatment goals such as mucosal healing. There are seven monoclonal antibody therapies excluding their biosimilars approved by the US Food and Drug Administration for induction and maintenance of clinical remission in IBD. Adverse side effects associated with almost all currently available drugs, especially biologics, is the main challenge in IBD management. Natural products have significant potential as therapeutic agents with an increasing role in health care. Given that natural products display great structural diversity and are relatively easy to modify chemically, they represent ideal scaffolds upon which to generate novel therapeutics. This review focuses on the pathology, currently available treatment options for IBD and associated challenges, and the roles played by natural products in health care. It discusses these natural products within the current biodiscovery research agenda, including the applications of drug discovery techniques and the search for next-generation drugs to treat a plethora of inflammatory diseases, with a major focus on IBD.

Gabapentin attenuates intestinal inflammation: Role of PPAR-gamma receptor

Gabapentin is an anticonvulsant drug that is also used for post-herpetic neuralgia and neuropathic pain. Recently, gabapentin showed anti-inflammatory effect. Nuclear factor kappa B (NFκB) is a regulator of the inflammatory process, and Peroxisome Proliferator-activated Receptor gamma (PPAR-gamma) is an important receptor involved in NFκB regulation. The aim of the present work was to study the potential role of PPAR-gamma receptor in gabapentin-mediated anti-inflammatory effects in a colitis experimental model. We induced colitis in rats using trinitrobenzenosulfonic acid and treated them with gabapentin and bisphenol A dicyldidyl ether (PPAR-gamma inhibitor). Macroscopic lesion scores, wet weight, histopathological analysis, mast cell count, myeloperoxidase, malondialdehyde acid, glutathione, nitrate/nitrite, and interleukin levels in the intestinal mucosa were determined. In addition, western blots were performed to determine the expression of Cyclooxygenase-2 (COX-2) and NFκB; Nitric Oxide Inducible Synthase (iNOS) and Interleukin 1 beta (IL-1β) levels were also determined. Gabapentin was able to decrease all inflammatory parameters macroscopic and microscopic in addition to reducing markers of oxidative stress and cytokines such as IL-1β and Tumor Necrosis Factor alpha (TNF-α) as well as enzymes inducible nitric oxide synthase and cyclooxygenase 2 and inflammatory genic regulator (NFκB). These effect attributed to gabapentin was observed to be lost in the presence of the specific inhibitor of PPAR-gamma. Gabapentin inhibits bowel inflammation by regulating mast cell signaling. Furthermore, it activates the PPAR-gamma receptor, which in turn inhibits the activation of NFκB, and consequently results in reduced activation of inflammatory genes involved in inflammatory bowel diseases.

Nuclear Receptors Regulate Intestinal Inflammation in the Context of IBD

Gastrointestinal (GI) homeostasis is strongly dependent on nuclear receptor (NR) functions. They play a variety of roles ranging from nutrient uptake, sensing of microbial metabolites, regulation of epithelial intestinal cell integrity to shaping of the intestinal immune cell repertoire. Several NRs are associated with GI pathologies; therefore, systematic analysis of NR biology, the underlying molecular mechanisms, and regulation of target genes can be expected to help greatly in uncovering the course of GI diseases. Recently, an increasing number of NRs has been validated as potential drug targets for therapeutic intervention in patients with inflammatory bowel disease (IBD). Besides the classical glucocorticoids, especially PPARγ, VDR, or PXR-selective ligands are currently being tested with promising results in clinical IBD trials. Also, several pre-clinical animal studies are being performed with NRs. This review focuses on the complex biology of NRs and their context-dependent anti- or pro-inflammatory activities in the regulation of gastrointestinal barrier with special attention to NRs already pharmacologically targeted in clinic and pre-clinical IBD treatment regimens.

Xylan from Pineapple Stem Waste: a Potential Biopolymer for Colonic Targeting of Anti-inflammatory Agent Mesalamine

We have successfully conjugated mesalamine (5-aminosalicylic acid, 5-ASA) with xylan, a biopolymer isolated from pineapple stem waste, to form xylan-5-ASA conjugate. The biopolymer was used to provide colon-targeting properties for 5-ASA, a golden standard anti-inflammatory agent commonly used for ulcerative colitis treatment. A series of data from FTIR spectroscopy, UV-Vis spectrophotometry, and HPLC confirmed the xylan-5-ASA conjugate formation. To ensure successful colon targeting properties, in vitro and in vivo drug release studies after oral administration of xylan-5-ASA conjugate to Wistar rats were performed. Xylan-5-ASA conjugate was able to retain 5-ASA release in the upper gastrointestinal tract fluid simulation but rapidly released 5-ASA in the rat colon fluid simulation. In vivo release profile shows a very low peak plasma concentration, reached at 6 h after xylan-5-ASA conjugate administration. The delayed release and the lower bioavailability of 5-ASA from xylan-5-ASA conjugate administration compared to free 5-ASA administration confirmed the successful local colon delivery of 5-ASA using xylan-5-ASA conjugate. The administration of xylan-5-ASA conjugate also exhibited greater efficacy in recovering 2,4,6-trinitrobenzene sulfonic acid-induced colon ulcer compared to free 5-ASA administration. Taken together, xylan isolated from pineapple stem waste is promising to obtain colon targeting property for 5-ASA.

Adherence to Asacol once daily versus divided regimen for maintenance therapy in ulcerative colitis: a prospective, multicenter, randomized study

Background/Aims

A once-daily (OD) regimen of 5-aminosalicylic acid (5-ASA) was easier to comply with than a divided daily (DD) regimen, and that treatment efficacy for ulcerative colitis (UC) was not affected by the dosing regimen. This study evaluated treatment adherence of OD and DD dosing in the Korean UC patients.

Methods

This study was a prospective, multicenter, randomized trial. UC patients were enrolled who have been in remission for more than 3 months. Patients were randomly assigned to the OD or DD group in a 1:1 ratio. The primary endpoint was adherence rate measured by tablet counts and self-reported adherence rate at 3, 6, 9, and 12 months. The relapse rate was measured at 1 year.

Results

Data from the 180 patients who were randomized were analyzed. Both self-reported adherence rate and adherence rate measured by tablet counts were not different at every points, including 1 year. The patients’ satisfaction of the OD group was higher than that of the DD group (P<0.001). At 1 year, 91.2% and 95.5% of patients in the OD group and DD group had maintained clinical remission, respectively (P=0.37).

Conclusions

The adherence rates were not different between the OD group and DD group. The patients’ satisfaction was higher in the OD group than in the DD group. 5-ASA OD dosing might have the same effect as DD for the maintenance of UC remission.