Mesalamine in the treatment and maintenance of remission of ulcerative colitis

Possible Drug-Drug Interactions Between Mesalamine and Tricyclic Antidepressants Through CYP2D6 Metabolism - In silico and In vitro Analyses

Mesalamine (mesalazine, 5-aminosalicylic acid, 5-ASA) is an essential anti-inflammatory agent both used for therapy and as a remission control in patients with inflammatory bowel diseases (IBD) such as ulcerative colitis (UC). Tricyclic antidepressants (TCAs) are used to alleviate remaining symptoms in patients already receiving IBD therapy or with quiescent inflammation. The cytochrome P4502D6 enzyme is involved in the metabolism of TCAs. Hence, it is crucial to investigate the role of CYP2D6 in 5-ASA metabolism. Initially, in silico analysis involving the docking of 5-ASA to CYP2D6 and molecular dynamics simulations was conducted. Next, the rate of O-demethylation of a nonfluorescent probe 3-[2-(N,N-diethyl-N-methylammonium)-ethyl]-7-methoxy-4-methylcoumarin (AMMC) into a fluorescent metabolite AMHC (3-[2-(N,N-diethyl-N-methylammonium)ethyl]-7-hydroxy-4-methylcoumarin) was optimized with baculosomes co-expressing human CYP2D6 and human P450 oxidoreductase (hCPR) to monitor CYP2D6 activity in a microtiter plate assay. The apparent Km and Vmax were found to be 1.30 μM and 32.68 pmol/min/mg of protein for the O-demethylation of AMMC to AMHC, and the reaction was linear for 40 min. Then, nonselective inhibition of CYP2D6 activity with various concentrations of 5-ASA was detected. Finally, the conversion of AMMC to metabolites was analyzed by HPLC-ESI-MS/MS spectrometry, and none were identified. Thus, this study suggests that concurrent use of mesalamine with TCA may lead to adverse effects, and CYP2D6 genotyping should be routinely performed on these patients to eliminate possible threats.

A practical approach to positioning therapies in ulcerative colitis

The therapeutic landscape of ulcerative colitis (UC) has undergone significant change over the last 2 decades. While there are multiple new therapies for the management of UC, long-term remission rates remain low, and this may be in part due to the difficulty of navigating a successful treatment strategy. In this review, we propose a rational framework for treatment selection, sequencing, and optimization in patients with UC. We outline treatment goals and targets for UC, followed by a discussion of the challenges in treatment selection and considerations to help guide a sequencing strategy. These include an assessment of a therapy's efficacy and safety, the convenience in the delivery of the therapy, ease of access, and patient-related factors. We then provide an overview of the currently approved therapies for UC, with an in-depth analysis of their advantages and disadvantages. Finally, we conclude with future directions in the management of UC, which include the use of naturopathic therapies, faecal microbiota therapy, the use of precision medicine, and other strategies such as combination therapy.

Comprehensive care of ulcerative colitis: new treatment strategies

INTRODUCTION

Ulcerative colitis is a chronic inflammatory condition of the colon driven by aberrant immune activation. Although advanced medical therapies form the cornerstone of ulcerative colitis management, unmet needs include failure to induce and sustain remission in a substantial proportion of patients and in managing acute severe ulcerative colitis. We review new treatment strategies that might improve patient outcomes in the management of moderate-to-severe ulcerative colitis.

AREAS COVERED

A literature search was conducted using the PubMed database, including studies published from inception to October 2024, selected for their relevance. Recognizing current limitations, this article reviews strategies to improve treatment outcomes in ulcerative colitis using advanced therapies. These approaches include early treatment initiation, dose optimization, positioning newer agents as first-line therapies, combination therapy, targeting novel therapeutic endpoints, and the management of acute severe ulcerative colitis.

EXPERT OPINION

The strategies discussed may contribute to establishing new standards of care aimed at achieving long-term remission and enhancing patient outcomes. Personalized therapy, which tailors treatment based on individual disease characteristics and risk factors, is anticipated to become a critical aspect of delivering more effective care in the future.

Influence of Mesalazine on Ferroptosis-Related Gene Expression in In Vitro Colorectal Cancer Culture

Background/Objectives: Colorectal cancer (CRC) is one of the most common oncological disorders. Its fundamental treatments include surgery and chemotherapy, predominantly utilizing 5-fluorouracil (5-FU). Despite medical advances, CRC continues to present a high risk of recurrence, metastasis and low survival rates. Consequently, significant emphasis has been directed towards exploring novel types of cell death, particularly ferroptosis. Ferroptosis is characterized by iron imbalance and the accumulation of lipid peroxides and reactive oxygen species (ROS), leading to cellular damage and death. Thus, the discovery of safe inducers of ferroptosis, offering new hope in the struggle against CRC, remains crucial. In this study, we applied the concept of drug repositioning, selecting mesalazine (MES), a non-steroidal anti-inflammatory drug (NSAID), for investigation. Methods: The study was conducted on the colon cancer cell line DLD-1 and normal intestinal epithelial cells from the CCD 841 CoN cell line. Both cell lines were treated with MES solutions at concentrations of 10, 20, 30, 40, and 50 mM. Cytotoxicity was assessed using the MTT assay, while ferroptosis-related gene expression analysis was performed using oligonucleotide microarrays, with RT-qPCR used for validation. Results: MES effectively reduces the viability of DLD-1 cells while minimally affecting normal intestinal cells. Subsequent oligonucleotide microarray analysis revealed that MES significantly alters the expression of 56 genes associated with ferroptosis. Conclusions: Our results suggest that MES may induce ferroptosis in CRC, providing a foundation for further research in this area.

Inflammation-targeted delivery of Urolithin A mitigates chemical- and immune checkpoint inhibitor-induced colitis

Inflammatory bowel disease (IBD) treatment often involves systemic administration of anti-inflammatory drugs or biologics such as anti-TNF-α antibodies. However, current drug therapies suffer from limited efficacy due to unresponsiveness and adverse side effects. To address these challenges, we developed inflammation-targeting nanoparticles (ITNPs) using biopolymers derived from the gum kondagogu (Cochlospermum gossypium) plant. These ITNPs enable selective drug delivery to inflamed regions, offering improved therapeutic outcomes. We designed ITNPs that specifically bind to inflamed regions in both human and mouse intestines, facilitating more effective, uniform, and prolonged drug delivery within the inflamed tissues. Furthermore, we demonstrated that oral administration of ITNPs loaded with urolithin A (UroA), a microbial metabolite or its synthetic analogue UAS03 significantly attenuated chemical- and immune checkpoint inhibitor- induced colitis in pre-clinical models. In conclusion, ITNPs show great promise for delivering UroA or its analogues while enhancing therapeutic efficacy at lower doses and reduced frequency compared to free drug administration. This targeted approach offers a potential solution to enhance IBD treatment while minimizing systemic side effects.

Nanoparticles encapsulated in Abelmoschus esculentus polysaccharide-based pellets as colon targeting approach

AIM(S)

This article explores the application of mesalazine-loaded nanoparticles (MLZ-NPs) encapsulated in Abelmoschus esculentus plant polysaccharide-based pellets (MLZ-NPs-Pellets) for ulcerative colitis.

METHODS

MLZ-NPs were prepared and evaluated for diameter, PDI, and entrapment efficiency. In-vitro efficacy study was conducted on Caco-2 cells. MLZ-NPs were encapsulated in polysaccharides to form MLZ-NPs-Pellets and characterised for efficacy in animals and targeting efficiency in human volunteers.

RESULTS

Optimised batch of MLZ-NPs were characterised for diameter, PDI, zeta potential and entrapment efficiency which was found to be 145.42 ± 6.75 nm, 0.214 ± 0.049, -31.63 mV and 77.65 ± 2.33(%w/w) respectively. ROS, superoxide and NF-kβ were well controlled in Caco-2 cells when treated with MLZ-NPs. In-vivo data revealed that some parameters (body weight, colon length, lipid peroxidase, and glutathione) recovered significantly in the DSS-induced mice model treated with oral MLZ-NPs-Pellets. Gamma scintigraphy revealed that the formulation can effectively target the colon within 600 min.

CONCLUSION

MLZ-NPs-Pellets can be effectively used for microbial-triggered colon targeting approach in treating ulcerative colitis.

Targeting glutamate carboxypeptidase II in IBD

Over the past decade, the zinc metalloenzyme glutamate carboxypeptidase (GCPII) has emerged as a novel therapeutic target for IBD. This enzyme is minimally expressed in healthy ileum or colon, but is profoundly upregulated in multiple IBD subtypes including: adult and pediatric Crohn's disease (CD), adult and pediatric ulcerative colitis (UC), and UC pouchitis. Encouragingly, small molecule GCPII inhibitors display promising efficacy in chemical and genetic preclinical colitis models. In this chapter we will: (1) review GCPII biology, (2) present the data confirming its upregulation in IBD patients at gene and protein levels, (3) discuss foundational pre-clinical studies that established the anti-colitis efficacy of small molecule GCPII inhibitors, and (4) introduce the rationale and development of a novel class of GCPII inhibitors, including lead compound (S)-IBD3540, which hold therapeutic promise for IBD.

A Comprehensive Review of Xanthan Gum-Based Oral Drug Delivery Systems

Xanthan gum (XG) is an exopolysaccharide synthesized by the aerobic fermentation of simple sugars using Xanthomonas bacteria. It comprises a cellulosic backbone with a trisaccharide side chain connected to alternative glucose residues in the main backbone through α (1→3) linkage. XG dissolves readily in cold and hot water to produce a viscous solution that behaves like a pseudoplastic fluid. It shows excellent resistance to enzymatic degradation and great stability throughout a broad temperature, pH, or salt concentration range. Additionally, XG is nontoxic, biocompatible, and biodegradable, making it a suitable carrier for drug delivery. Furthermore, the carboxylic functions of pyruvate and glucuronic acid offer a considerable opportunity for chemical modification to meet the desired criteria for a specific application. Therefore, XG or its derivatives in conjunction with other polymers have frequently been studied as matrices for tablets, nanoparticles, microparticles, and hydrogels. This review primarily focuses on the applications of XG in various oral delivery systems over the past decade, including sustained-release formulations, gastroretentive dosage forms, and colon-targeted drug delivery. Source, production methods, and physicochemical properties relevant to drug delivery applications of XG have also been discussed.

MMX mesalamine in ulcerative colitis: Major advantages towards classical mesalamine formulations

Medical therapy is the cornerstone of ulcerative colitis (UC) management and aims to induce and maintain remission. In case of mild-to-moderate UC, mesalamine (5-ASA) is the first-line option. 5-ASA requires local release at the level of the inflamed mucosa to exert its therapeutic action. While rectal preparations are useful in distal colitis, in cases of UC of at least rectosigmoid extent, guidelines suggest the association of oral and rectal 5-ASA. Mesalamine with Multi Matrix System® technology (MMX mesalamine) is an oral, high-strength (1.2 g/tablet), once-daily formulation of 5-ASA, designed to provide delayed and prolonged release throughout the entire colon. Clinical trials demonstrated a strong efficacy in inducing and maintaining clinical and endoscopic remission in active mild-to-moderate UC. The efficacy is related to specific colonic drug-delivery, to its high-dosage and once-daily administration, thus improving patients' adherence and outcomes. The specific colonic-delivery is also associated with very low rates of systemic absorption and adverse events (AEs). With this comprehensive review we aimed to summarize current knowledge on MMX mesalamine in mild-to-moderate UC, in terms of clinical pharmacology, efficacy and safety, also compared to other 5-ASA products. In addition we provided an expert opinion on the topic, examining the implications on clinical practice.

Mesalazine-induced myocarditis in a patient with ulcerative colitis: a case report

Background

Mesalazine is an established first-line therapy for inflammatory bowel disease (IBD) and remains the mainstay of treatment for mild to moderate ulcerative colitis (UC). Both mesalazine and UC are rare but recognized causes of myopericarditis. Cardiac magnetic resonance (CMR) is a non-invasive method of assessing for myopericarditis. This case reports highlights the importance of early CMR in diagnosis, and management of myocarditis in a patient with IBD.

Case summary

A 28-year-old male was admitted with a 2-day history of chest pain. Three weeks prior to this presentation, the patient was initiated on mesalazine for UC. Serum troponin T and C-reactive protein were elevated. An echocardiogram showed borderline low left ventricular systolic function (LVEF = 50-55%). A CMR showed extensive patchy late gadolinium enhancement (LGE) in the mid to epicardial basal and mid lateral wall. The findings were consistent with acute myocarditis, and a working diagnosis of mesalazine-induced myocarditis was made. Mesalazine was stopped and guideline-directed anti-inflammatories initiated. Oral prednisolone was also introduced for IBD control. Follow-up CMR at four months showed near complete resolution of LGE.

Discussion

Myocarditis in the context of IBD may be infective, immune-mediated or due to mesalazine hypersensitivity. Histological conformation was not available in this case. This case report highlights the importance of access to early CMR in order establish the diagnosis and withdrawal of the culprit medication. In the majority of cases, CMR will replace the need for endomyocardial biopsy; however, this may still be required in the most severe cases.

Efficacy and safety of Xileisan combined with mesalazine for ulcerative colitis: A meta-analysis and trial sequential analysis

BACKGROUND

The benefits and risks of Xileisan (XLS) in the treatment of ulcerative colitis (UC) remain unclear.

AIM

The present study aimed to evaluate the efficacy and safety of the combination of XLS and mesalazine when treating UC.

METHODS

We searched eight databases for clinical trials evaluating the combination of XLS and mesalazine in the treatment of UC, up to January 2024. Meta-analysis and trial sequential analysis (TSA) were performed using Revman 5.3 and TSA 0.9.5.10 beta, respectively.

RESULTS

The present study included 13 clinical studies involving 990 patients, of which 501 patients received XLS combined with mesalazine while 489 patients received mesalazine alone. The meta-analysis showed that, in terms of efficacy, the combination of XLS and mesalazine significantly improved the clinical efficacy rate by 22% [risk ratio (RR) = 1.22; 95%CI: 1.15-1.28; P < 0.00001] and mucosal improvement rate by 25% (RR = 1.25; 95%CI: 1.12-1.39; P = 0.0001), while significantly reducing the duration of abdominal pain by 2.25 days [mean difference (MD) = -2.25; 95%CI: -3.35 to -1.14; P < 0.0001], diarrhea by 2.06 days (MD = -2.06; 95%CI: -3.92 to -0.20; P = 0.03), hematochezia by 2.32 days (MD = -2.32; 95%CI: -4.02 to -0.62; P = 0.008), tumor necrosis factor alpha by 16.25 ng/mL (MD = -16.25; 95%CI: -20.48 to -12.01; P < 0.00001), and interleukin-6 by 14.14 ng/mL (MD = -14.14; 95%CI: -24.89 to -3.39; P = 0.01). The TSA indicated conclusiveness in the meta-analysis of the efficacy endpoints. In terms of safety, the meta-analysis revealed that the combination of XLS and mesalazine did not increase the occurrence of total and gastrointestinal adverse events, abdominal distension, and erythema (P > 0.05). The TSA showed non conclusive findings in the meta-analysis of the safety endpoints. Harbord's test showed no publication bias (P = 0.734).

CONCLUSION

Treatment with XLS alleviated the clinical symptoms, intestinal mucosal injury, and inflammatory response in patients with UC, while demonstrating good safety.

Explore the underlying oral efficacy of α-, β-, γ-Cyclodextrin against the ulcerative colitis using in vitro and in vivo studies assisted by network pharmacology

The incidence of ulcerative colitis (UC) is rising worldwide. As a refractory and recurrent disease, UC could seriously affect the patients' quality of life. However, current clinical medical treatments for UC are accompanied by various side effects, especially for long-term applications. Here, the underlying efficacy of cyclodextrins (CDs) was studied. As common excipients, CDs endow proven safety for long-term applications. Results of predictive methods derived from network pharmacology prompted the potential anti-inflammatory effects of CDs by oral administration. RAW264.7 cell experiments verified that CDs could inhibit the excessive secretion of TNF-α (β-CD > α-CD ≈ γ-CD), IL-6, and NO (α-CD > β-CD ≈ γ-CD) as predicted. In mice with DSS-induced acute UC, oral administration of CDs could effectively mitigate the pathological damage of colon tissue and reduce the level of inflammatory mediators. Moreover, 16S rRNA sequencing displayed that gut microbes disturbed by DSS were significantly regulated by CDs. Conclusively, the study showed the therapeutic application prospects of CDs in UC treatment and indicated the feasibility and advantages of developing 'new' therapeutic activities of 'old' ingredients.Communicated by Ramaswamy H. Sarma.

Formulation, Characterization and In Vitro Evaluation of Mesalamine and Bifidobacterium bifidum Loaded Hydrogel Beads in Capsule System for Colon Targeted Delivery

Mesalamine is a first-line drug for the treatment of inflammatory bowel diseases. However, its premature release associated with marketed formulations leads to adverse effects like gastric trouble, vomiting, and diarrhoea. To minimize these side effects, colon-targeted drug delivery is essential. Besides conventional pharmacotherapy, bifidogenic probiotics with anti-inflammatory activity has been reported to elicit a significant impact on the remission of ulcerative colitis. Bifidogenic probiotics being acid-labile necessitate developing a gastro-resistant formulation for enhancing the delivery of viable cells to the colon. The present study was aimed at developing a fixed-dose unit dosage form of mucoadhesive hydrogel beads loaded with mesalamine and Bifidobacterium bifidum further encapsulated in Eudragit® capsules for the targeted drug delivery at colonic pH. The hydrogel beads were prepared by ionotropic gelation, with the effect of single and dual-crosslinking approaches on various formulation characteristics studied. Standard size 00 Eudragit® gastro-resistant capsules were prepared and the dried beads were filled inside the capsule shells. The formulation was then evaluated for various parameters, including physicochemical characterization, in vitro biocompatibility and anti-inflammatory activity. No interaction was observed between the drug and the polymers, as confirmed through FTIR, XRD, and DSC analysis. The mean particle size of the beads was ~ 457-485 µm. The optimized formulation showed a drug entrapment efficiency of 95.4 ± 2.58%. The Eudragit® capsule shells disintegrated in approximately 13 min at pH 7.4. The mucoadhesive hydrogel beads sustained the drug release above 18 h, with 50% of the drug released by the end of 12 h. The optimized formulation demonstrated significant (p < 0.05) gastro-resistance, biocompatibility, sustained drug release, cell viability, and anti-inflammatory activity.

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.

Anti-oxidant and anti-inflammatory potential of different polymer-based mesalamine delayed-release granules in TNBS-induced ulcerative colitis in wistar rats

Ulcerative colitis (UC) is an inflammatory condition of colon characterized by severe damage to the innermost colon tissues. A number of studies described the use of medication delivery systems based on natural polymers like polysaccharides for the purpose of reaching the colon. In this research, polymer-based mesalamine delayed-release granules (DRGs) were tested for their antioxidant and anti-inflammatory efficacy against UC. Chitosan (C), pectin (P), and pectin-chitosan (PC) mesalamine (M) DRGs were prepared and characterized. Data revealed satisfactory compatibility, flow, packing properties, drug release pattern, and delayed drug release by DRGs. Wistar rats were treated with 2,4,6-trinitrobenzenesulfonic acid (TNBS) (100 mg/kg) via rectal administration. Mesalamine and mesalamine DRGs (50 mg/kg) were administered orally separately for 14 days. Biomarkers of oxidative stress, inflammation, hematological tests, colon profile, and histopathology were performed. The findings demonstrated the good efficacy of the polysaccharides in delivering mesalamine to colon. Mesalamine and mesalamine DRGs based on various polymers showed significant antioxidant and anti-inflammatory effects in rats with UC. Mesalamine granules significantly attenuated colon lipid peroxidation, nitrites, myeloperoxidase activity, and interleukin-1β levels, and improved anti-oxidants (GSH, SOD). Data showed upregulation of Nrf2 activity by mesalamine granules with CM-DRGs showing maximum effect. Mesalamine and different polymer-based mesalamine DRGs significantly attenuated TNBS-induced decline in body weight, ulcer severity, and colon damage. CM-DRGs showed the most pronounced ameliorative effect on colon and hematology parameters via anti-oxidant and anti-inflammatory activities. Chitosan can be used as a carrier for oral colon delivery of mesalamine in DRG formulation for enhanced therapeutic efficacy in UC.

Effects of Huzhangoside C on Dextran Sodium Sulfate-Stimulated Colitis in Mice

Chronic inflammation is a major risk factor for cancer. Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract, ultimately leading to a breakdown of intestinal barrier function. Clematis florida var. plena is a folk prescription used to treat inflammation and rheumatism in She pharmacy. The bioactivity of C. florida var. plena is primarily due to triterpene saponins. Huzhangoside C (HZ) is an active component of C. florida var. plena. In this study, the anti-inflammatory effect of HZ on a mouse colitis model induced by dextran sulfate sodium (DSS) was investigated. Result indicated a notable reduction in body weight loss and colon length shortening in HZ-mediated mice compared to DSS-stimulated control mice. Furthermore, inflammatory signaling mechanisms involving interleukin-6 and tumor necrosis factor-α were suppressed in HZ-treated mice. HZ treatment significantly suppressed the expression of nuclear factor kappa B (NF-κB), STAT3, and iNOS in colon tissue. After HZ treatment, malondialdehyde and nitric oxide levels were significantly decreased, while Nrf-2, superoxide dismutase, and glutathione expression levels were notably improved. The result indicated that HZ could activate the Nrf-2 signal cascade, inhibit the expression of NF-κB, eNOS, and STAT3, and enhance the intestinal barrier function of DSS stimulated ulcerative colitis intestinal injury. The results suggest that HZ is potential anti-inflammatory agent for treating IBD.

Research progress of natural plant polysaccharides inhibiting inflammatory signaling pathways and regulating intestinal flora and metabolism to protect inflammatory bowel disease

Natural plant polysaccharides are macromolecular substances with a wide range of biological activities. They have a wide range of biological activities, especially play an important role in the treatment of inflammatory bowel disease. The molecular weight of polysaccharides, the composition of monosaccharides and the connection of glycosidic bonds will affect the therapeutic effect on inflammatory bowel disease. Traditional Chinese medicine plant polysaccharides and various types of plant polysaccharides reduce the levels of inflammatory cytokines IL-1β, IL-6, IL-8 and IL-17, increase the level of anti-inflammatory factor IL-10, regulate NF-κB signaling pathway, and NLRP3 inflammasome to relieve colitis. At the same time, they can play a protective role by regulating the balance of intestinal flora in mice with colitis and increasing the abundance of probiotics to promote the metabolism of polysaccharide metabolites SCFAs. This review summarizes the research on the treatment of inflammatory bowel disease by many natural plant polysaccharides, and provides a theoretical basis for the later treatment of polysaccharides on inflammatory bowel disease.

The role of microbiota and its modulation in colonic diverticular disease

BACKGROUND

Diverticular disease (DD) is a common condition in Western countries. The role of microbiota in the pathogenesis of DD and its related symptoms has been frequently postulated since most complications of this disease are bacteria-driven and most therapies rely on microbiota modulation. Preliminary data showed fecal microbial imbalance in patients with DD, particularly when symptomatic, with an increase of pro-inflammatory and potentially pathogenetic bacteria. In addition, bacterial metabolic markers can mirror specific pathways of the disease and may be even used for monitoring treatment effects. All treatments currently suggested for DD can affect microbiota structure and metabolome compositions.

PURPOSE

Sparse evidence is available linking gut microbiota perturbations, diverticular disease pathophysiology, and symptom development. We aimed to summarize the available knowledge on gut microbiota evaluation in diverticular disease, with a focus on symptomatic uncomplicated DD, and the relative treatment strategies.

Manipulating Microbiota in Inflammatory Bowel Disease Treatment: Clinical and Natural Product Interventions Explored

Inflammatory bowel disease (IBD) is a complex multifactorial chronic inflammatory disease, that includes Crohn's disease (CD) and ulcerative colitis (UC), having progressively increasing global incidence. Disturbed intestinal flora has been highlighted as an important feature of IBD and offers promising strategies for IBD remedies. A brief overview of the variations occurring in intestinal flora during IBD is presented, and the role of the gut microbiota in intestinal barrier maintenance, immune and metabolic regulation, and the absorption and supply of nutrients is reviewed. More importantly, we review drug research on gut microbiota in the past ten years, including research on clinical and natural drugs, as well as adjuvant therapies, such as Fecal Microbiota Transplantation and probiotic supplements. We also summarize the interventions and mechanisms of these drugs on gut microbiota.

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.

Aminosalicylates target GPR35, partly contributing to the prevention of DSS-induced colitis

GPR35, a class A G-protein-coupled receptor, is considered an orphan receptor; the endogenous ligand and precise physiological function of GPR35 remain obscure. GPR35 is expressed relatively highly in the gastrointestinal tract and immune cells. It plays a role in colorectal diseases like inflammatory bowel diseases (IBDs) and colon cancer. More recently, the development of GPR35 targeting anti-IBD drugs is in solid request. Nevertheless, the development process is in stagnation due to the lack of a highly potent GPR35 agonist that is also active comparably in both human and mouse orthologs. Therefore, we proposed to find compounds for GPR35 agonist development, especially for the human ortholog of GPR35. As an efficient way to pick up a safe and effective GPR35 targeting anti-IBD drug, we screened Food and Drug Administration (FDA)-approved 1850 drugs using a two-step DMR assay. Interestingly, we found aminosalicylates, first-line medicine for IBDs whose precise target remains unknown, exhibited activity on both human and mouse GPR35. Among these, pro-drug olsalazine showed the most potency on GPR35 agonism, inducing ERK phosphorylation and β-arrestin2 translocation. In dextran sodium sulfate (DSS)-induced colitis, the protective effect on disease progression and inhibitory effect on TNFα mRNA expression, NF-κB and JAK-STAT3 pathway of olsalazine are compromised in GPR35 knock-out mice. The present study identified a target for first-line medicine aminosalicylates, highlighted that uncleaved pro-drug olsalazine is effective, and provided a new concept for the design of aminosalicylic GPR35 targeting anti-IBD drug.

Platycodon grandiflorus polysaccharide regulates colonic immunity through mesenteric lymphatic circulation to attenuate ulcerative colitis

Platycodon grandiflorus polysaccharide (PGP) is one of the main components of P. grandiflorus, but the mechanism of its anti-inflammatory effect has not been fully elucidated. The aim of this study was to evaluate the therapeutic effect of PGP on mice with dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) and explore the underlying mechanisms. The results showed that PGP treatment inhibited the weight loss of DSS-induced UC mice, increased colon length, and reduced DAI, spleen index, and pathological damage within the colon. PGP also reduced the levels of pro-inflammatory cytokines and inhibited the enhancement of oxidative stress and MPO activity. Meanwhile, PGP restored the levels of Th1, Th2, Th17, and Treg cell-related cytokines and transcription factors in the colon to regulate colonic immunity. Further studies revealed that PGP regulated the balance of colonic immune cells through mesenteric lymphatic circulation. Taken together, PGP exerts anti-inflammatory and anti-oxidant effect and regulates colonic immunity to attenuate DSS-induced UC through mesenteric lymphatic circulation.

Gut microbial metabolism of 5-ASA diminishes its clinical efficacy in inflammatory bowel disease

For decades, variability in clinical efficacy of the widely used inflammatory bowel disease (IBD) drug 5-aminosalicylic acid (5-ASA) has been attributed, in part, to its acetylation and inactivation by gut microbes. Identification of the responsible microbes and enzyme(s), however, has proved elusive. To uncover the source of this metabolism, we developed a multi-omics workflow combining gut microbiome metagenomics, metatranscriptomics and metabolomics from the longitudinal IBDMDB cohort of 132 controls and patients with IBD. This associated 12 previously uncharacterized microbial acetyltransferases with 5-ASA inactivation, belonging to two protein superfamilies: thiolases and acyl-CoA N-acyltransferases. In vitro characterization of representatives from both families confirmed the ability of these enzymes to acetylate 5-ASA. A cross-sectional analysis within the discovery cohort and subsequent prospective validation within the independent SPARC IBD cohort (n = 208) found three of these microbial thiolases and one acyl-CoA N-acyltransferase to be epidemiologically associated with an increased risk of treatment failure among 5-ASA users. Together, these data address a longstanding challenge in IBD management, outline a method for the discovery of previously uncharacterized gut microbial activities and advance the possibility of microbiome-based personalized medicine.

In vitro and in vivo evaluation of a pH-, microbiota- and time-based oral delivery platform for colonic release

Several formulation strategies have been proposed for oral colon delivery, particularly for the therapy of inflammatory bowel disease (IBD). However, targeting the large intestine remains a challenging goal. The aim of this study was to develop and evaluate a novel type of drug delivery system, which is based on multiple drug release triggers for reliable performance. The system consists of: (i) a drug core, (ii) an inner swellable low-viscosity hydroxypropyl methylcellulose (HPMC) layer, and (iii) an outer film coating based on a Eudragit® S:high-methoxyl (HM) pectin (7:3 w/w) blend, optionally containing chitosan. Convex immediate release tablets (2 or 4 mm in diameter) containing paracetamol or 5-aminosalicylic acid (5-ASA) were coated in a fluid bed. The double-coated tablets exhibited pulsatile release profiles when changing the release medium from 0.1 N HCl to phosphate buffer pH 7.4. Also, drug release was faster in simulated colonic fluid (SCF) in the presence of fecal bacteria from IBD patients compared to control culture medium from tablets with outer Eudragit® S: HM pectin: chitosan coatings. The latter systems showed promising results in the control of the progression of colitis and alteration of the microbiota in a preliminary rat study.

Mucoadhesive Nanoparticles Enhance the Therapeutic Effect of Dexamethasone on Experimental Ulcerative Colitis by the Local Administration as an Enema

Background

As the first-line drug to treat ulcerative colitis (UC), long-term use of glucocorticoids (GCs) produces severe toxic and side effects. Local administration as enema can increase the local GCs concentrations and reduce systemic exposure to high oral doses by directly delivering GCs to the inflammation site in the distal colorectum. However, UC patients are often accompanied by diarrhea, leading to the short colonic residence time of GCs and failure to exert their function fully.

Purpose

A kind of mucoadhesive nanoparticles (NPs) loading different dexamethasone derivatives (DDs) were developed, which could attach to the positively charged inflammatory colonic mucosa through electrostatic adsorption after administered by enema, thereby improving the local concentration and achieving effective targeted therapy for UC.

Methods

Two DDs, dexamethasone hemisuccinate and dexamethasone phosphate, were synthesized. In NPs preparation, The core PEI-DDs NPs were built by the electrostatic adsorption of DDs and the cationic polymer polyethyleneimine (PEI). Then, the natural polyanionic polysaccharide sodium alginate (SA) was electronically coated around NPs to construct the final SA-PEI-DDs NPs, followed by the in vitro stability and release tests, in vitro and in vivo colonic mucosal adhesion tests. In the in vivo anti-UC test, the experimental colitis mice were induced by 2,4,6-trinitrobenzenesulfonic acid. The body weight and disease activity index changes were measured, and the myeloperoxidase activity, pro-inflammatory cytokines concentration, and hematoxylin and eosin staining were also investigated to evaluate the therapeutic effect of NPs.

Results

The structures of two DDs were demonstrated by ¹H-NMR and MS. Both NPs were negatively charged and achieved high loading efficiency of DDs, while their particle sizes were significantly different. NPs showed good stability and sustained release properties in the simulated colonic environment. Moreover, the negative charge on the of NPs surface made them easier to adhere to the positively charged inflammatory colonic mucosa, thereby enhancing the enrichment and retention of DDS in the colitis site. Furthermore, the NPs exhibited better therapeutic effects than free Dex on the experimental colitis mice induced by TNBS through the enema rectal.

Conclusion

These results indicated the mucoadhesive NPs as a kind of novel nano-enema showed great potential to achieve efficient treatment on UC.

Mesalazine-PAMAM Nanoparticles for Transporter-Independent Intracellular Drug Delivery: Cellular Uptake and Anti-Inflammatory Activity

Background

Mesalazine is one of the main drugs used to treat inflammatory bowel diseases. However, its applicability is limited by its rapid inactivation and removal from the organism, as well as the need for its membrane transporter-dependent cellular uptake to exert therapeutic effect. The present study involved the development of an innovative nanocarrier, based on poly(amidoamine) (PAMAM) dendrimer of the 4th generation, to obtain higher concentrations of the drug in the intestinal epithelial cells, thus increasing its anti-inflammatory potential. The work involved synthesis and in vitro characterization of covalent PAMAM-mesalazine conjugate with succinic linker.

Results

PAMAM-mesalazine conjugate was synthesized and characterized by ¹H NMR, ¹³C NMR, FTIR and MALDI-TOF MS. This allowed to confirm the purity of the obtained compound and intermediates. Based on the analyses, it was found that ~45 drug molecules were successfully attached to one molecule of PAMAM dendrimer. The conjugate was then characterized in terms of hydrodynamic diameter, zeta potential, spectral properties, drug release from the carrier, as well as cellular uptake and cytotoxicity in two in vitro models of gastrointestinal epithelium (CaCo-2 and HT-29 human cell lines). Analyzing cellular parameters related to the specific mechanism of action of mesalazine (inhibition of NF-κB signaling, decrease in interleukin and prostaglandin synthesis, and ROS scavenging), we showed that such a dendrimer-based carrier may enhance cellular uptake of the drug, which translated into its improved anti-inflammatory efficacy.

Conclusion

The use of PAMAM macromolecule as a carrier for mesalazine increases the bioavailability of the drug, ensuring enhanced cellular uptake and bypassing the need to utilize mesalazine-specific membrane transporters. All these characteristics translate into an improved anti-inflammatory activity of mesalazine in vitro. In conjunction with appropriately designed in vivo studies, such a compound may prove to be a promising alternative to the therapeutics currently used in inflammatory bowel diseases.

Effects of the Antioxidant Quercetin in an Experimental Model of Ulcerative Colitis in Mice

Background and Objectives: Quercetin, a member of the flavanol family found in many fruits, vegetables, leaves and grains has been found to have a wide range of biological effects on human physiology. The aim of this study was to investigate the effects of quercetin, when administered orally in the form of the water-soluble inclusion complex with hydroxypropyl-b-cyclodextrin (Que-HP-β-CD), in an experimental model of ulcerative colitis in mice. Materials and Methods: Animals received either Dextran Sodium Sulphate (DSS), to induce colitis, + Que-HP-β-CD (Group A), DSS alone (Group B) or no intervention (control, Group C) for 7 days. All animals were weighed daily, and evaluation of colitis was performed using the Disease Activity Index (DAI). On day 7 a blood sample was taken from all animals, they were then euthanised, the large intestine was measured, and histological and immunochemical analyses were performed. Results: The DAI demonstrated an increase over time for the groups receiving DSS (Groups A and B) compared with the control group (Group C), with a significant degree of protection being observed in the group that also received quercetin (Group A): The DAI over time slope for Group B was higher than that for Group A by 0.26 points/day (95% Cl 0.20−0.33, p < 0.01). Weight calculations and immunohistochemistry results validated the DAI findings. Conclusions: In conclusion, the administration of quercetin in an ulcerative colitis model in mice presents a therapeutic/prophylactic potential that warrants further investigation.

Repurposing a Drug Targeting Inflammatory Bowel Disease for Lowering Hypertension

Background The gut and gut microbiota, which were previously neglected in blood pressure regulation, are becoming increasingly recognized as factors contributing to hypertension. Diseases affecting the gut such as inflammatory bowel disease (IBD) present with aberrant energy metabolism of colonic epithelium and gut dysbiosis, both of which are also mechanisms contributing to hypertension. We reasoned that current measures to remedy deficits in colonic energy metabolism and dysbiosis in IBD could also ameliorate hypertension. Among them, 5-aminosalicylic acid (5-ASA; mesalamine) is a PPARγ (peroxisome proliferator-activated receptor gamma) agonist. It attenuates IBD by a dual mechanism of selectively enhancing colonic epithelial cell energy metabolism and ameliorating gut dysbiosis. Methods and Results A total of 2 groups of 11- to 12-week-old male, hypertensive, Dahl salt-sensitive (S) rats were gavaged with (n=10) or without (n=10) 5-aminosalicylic acid (150 mg/kg) for 4 weeks. Rats receiving 5-aminosalicylic acid treatment had a lower mean blood pressure than controls (145±3 mm Hg versus 153±4 mm Hg; P<0.0001). This reduction in blood pressure was accompanied by increased activity of PPARγ, increased expression of energy metabolism-related genes, and lowering of the Firmicutes/Bacteroidetes ratio in the colon, the reduction of which is a marker for the correction of gut dysbiosis. Furthermore, these data were consistent with the American Gut Project wherein the Firmicutes/Bacteroidetes ratio of non-IBD (n=611) patients was significantly lower than patients with IBD (n=631). Conclusions 5-Aminosalicylic acid could be repurposed for hypertension by specifically enhancing the gut energy metabolism and correction of microbiota dysbiosis.

Living With Inflammatory Bowel Disease: Online Surveys Evaluating Patient Perspectives on Treatment Satisfaction and Health-Related Quality of Life

Background

The quality of life of persons living with inflammatory bowel disease (IBD) is impacted by the physical and psychosocial burdens of disease, as well as by their satisfaction with the quality of care they receive. We sought to better understand (1) the drivers of satisfaction with treatment, including treatment goals, treatment selection, and attributes of patient/health care professional (HCP) interactions, and (2) how IBD symptoms affect aspects of daily life and overall quality of life.

Methods

Two online questionnaires were accessed via MyCrohnsAndColitsTeam.com. The Treatment Survey assessed desired treatment outcomes, past and present therapies, and experiences with the patient's primary treating HCP. The Quality of Life survey assessed respondents' most problematic IBD symptoms and their influence on family and social life, work, and education. Respondents had Crohn's disease (CD) or ulcerative colitis (UC), were 19 years or older, and resided in the United States. All responses were anonymous.

Results

The Treatment Experience survey was completed by 502 people (296 CD, 206 UC), and the Quality of Life survey was completed by 302 people (177 CD, 125 UC). Reduced pain, diarrhea, disease progression, and fatigue were the most desired goals of treatment. Biologics and 5-aminosalicylates were reported as a current or past treatment by the greatest proportion of patients with CD and UC, respectively. A numerically lower proportion of respondents with UC than CD reported use of biologic or small molecule therapy; conversely, a numerically greater proportion of respondents with UC than CD reported these drugs to be very or extremely effective. The HCP was key in the decision to switch to, and in the selection of, biologic or small molecule therapy. Overall satisfaction with an HCP was greatly driven by the quality and quantity of the communication and of the time spent with the HCP. Troublesome abdominal symptoms most impacted aspects of social and family life. Emotional challenges associated with IBD were experienced by most respondents.

Conclusions

Treatment goals of respondents seem to align with HCPs overall treatment goals, including control of gastrointestinal symptoms and prevention of disease progression. Persons with UC might be offered biologic and small molecule therapies less often, despite reported high efficacy by users. Feeling heard and understood by the HCP are key drivers of treatment satisfaction. Quality communication in the patient/HCP relationship enables a better understanding of the patients' goals, disease burden, and emotional needs, which are all key factors to consider when developing a personalized and comprehensive treatment plan and optimizing quality of life.

The insoluble excretion of multi-matrix system mesalazine preparations in patients with ulcerative colitis

BACKGROUND

Multi-matrix mesalazine (MMX) is an important treatment for ulcerative colitis (UC); however, it is often excreted intact, which increases the risk of relapse. This study aimed to clarify the risk factors for insoluble MMX excretion.

METHODS

The subjects were 102 UC patients who were newly prescribed MMX alone to induce remission. Their stools were evaluated on the Bristol Stool Form Scale (BSFS), the presence/absence of insoluble MMX excretion was investigated in interviews, and defecation frequency at the start of treatment and disease type were retrospectively investigated by examining their medical records.

RESULTS

The insoluble excretion rate (IER) was 14.7%. It tended to be higher in the patients with left-sided colitis or extensive colitis, although the differences among the disease types were not significant (p = 0.053). The mean defecation frequency of the patients that reported insoluble MMX excretion was significantly higher than that of the patients that did not report it (6.27 ± 5.28 vs. 3.69 ± 3.17, p < 0.05). The IER tended to be higher among the patients with soft stools (4.5%, 21.9%, and 23.1% in those with BSFS scores of ≤ 4, 5, and ≥ 6, respectively). In ROC analysis of defecation frequency, ≥ 3.5 defecations was found to exhibit sensitivity and specificity of 66.7% and 65.5%, respectively, for predicting insoluble MMX excretion.

CONCLUSIONS

The likelihood of insoluble MMX excretion is influenced by defecation frequency and the extent of inflammation. It is important to keep the possibility of insoluble excretion in mind when prescribing MMX.

Mesalamine-Mediated Amelioration of Experimental Colitis in Piglets Involves Gut Microbiota Modulation and Intestinal Immune Cell Infiltration

Mesalamine (MES), also known as 5-aminosalicylic acid, is effective in treating mild to moderate ulcerative colitis (UC). The mechanisms of its actions are not fully elucidated. The aim of this study was to investigate the effects of MES treatment on intestinal microbiota and immune system in an dextran sulfate sodium (DSS)-induced UC model in postweaning piglets. Eighteen weaned piglets were assigned randomly to the following treatments: control group (CON, distilled water), DSS group (DSS, 3% DSS), and MES group (MES, 3% DSS + 2 g/day MES). Our results showed that MES treatment alleviates DSS-induced colitis in piglets, as evidenced by a reduced diarrhea index score and increased average daily gain (P < 0.05). This is accompanied by decreased diamine oxidase activity, D-lactate level (P < 0.05), and attenuated mucosal damage. MES treatment also decreased the abundance of Methanogens and reduced colon CD11b+ macrophage and CD3+ T-cell infiltrations in piglets with DSS-induced colitis (P < 0.05). Collectively, these data indicate that MES treatment-mediated colitis protection may involve microbiota and immune cell alterations.

Patient-derived organoids for therapy personalization in inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders of the intestinal tract that have emerged as a growing problem in industrialized countries. Knowledge of IBD pathogenesis is still incomplete, and the most widely-accepted interpretation considers genetic factors, environmental stimuli, uncontrolled immune responses and altered intestinal microbiota composition as determinants of IBD, leading to dysfunction of the intestinal epithelial functions. In vitro models commonly used to study the intestinal barrier do not fully reflect the proper intestinal architecture. An important innovation is represented by organoids, 3D in vitro cell structures derived from stem cells that can self-organize into functional organ-specific structures. Organoids may be generated from induced pluripotent stem cells or adult intestinal stem cells of IBD patients and therefore retain their genetic and transcriptomic profile. These models are powerful pharmacological tools to better understand IBD pathogenesis, to study the mechanisms of action on the epithelial barrier of drugs already used in the treatment of IBD, and to evaluate novel target-directed molecules which could improve therapeutic strategies. The aim of this review is to illustrate the potential use of organoids for therapy personalization by focusing on the most significant advances in IBD research achieved through the use of adult stem cells-derived intestinal organoids.

Calprotectin in Low anterior resection syndrome patients; a new insight into diagnosis and management: A pilot study

BACKGROUND AND STUDY AIM

Low anterior resection syndrome (LARS) has been reported to occur in up to 80% of patients after low anterior resection (LAR). This study aimed to investigate the role of fecal calprotectin in the diagnosis of LARS in patients subjected to LAR.

PATIENTS AND METHODS

This was a pilot study conducted on a group of patients that developed LARS after LAR who presented to the colorectal unit of Cairo University Hospital from November 2019 to April 2021. Fecal calprotectin levels were measured for all 36 eligible patients with persistent symptoms of LARS and those with high levels were treated using mesalamine tablets (500 mg) twice daily for one month and then once daily for another five months.

RESULTS

The study participants were treated using mesalamine and re-evaluated after six months. Twenty (55.5%) of the 36 patients experienced marked improvement while 10 (27.7%) improved from major to minor LARS with decreased levels of calprotectin. Six (16.6%) patients showed no significant improvement in symptoms (high LARS score) and still had high levels of fecal calprotectin.

CONCLUSION

Fecal calprotectin can be a useful tool in the diagnosis and treatment planning of persistent LARS. Our study also demonstrated the efficacy of immune modulators such as mesalamine (pentasa) in treating LARS in patients who are unresponsive to conventional dietary restrictions.

Liver-side of inflammatory bowel diseases: Hepatobiliary and drug-induced disorders

Hepatobiliary disorders are among the most common extraintestinal manifestations in inflammatory bowel diseases (IBD), both in Crohn’s disease and ulcerative colitis (UC), and therefore represent a diagnostic challenge. Immune-mediated conditions include primary sclerosing cholangitis (PSC) as the main form, variant forms of PSC (namely small-duct PSC, PSC-autoimmune hepatitis overlap syndrome and IgG4-related sclerosing cholangitis) and granulomatous hepatitis. PSC is by far the most common, presenting in up to 8% of IBD patients, more frequently in UC. Several genetic foci have been identified, but environmental factors are preponderant on disease pathogenesis. The course of the two diseases is typically independent. PSC diagnosis is based mostly on typical radiological findings and exclusion of secondary cholangiopathies. Risk of cholangiocarcinoma is significantly increased in PSC, as well as the risk of colorectal cancer in patients with PSC and IBD-related colitis. No disease-modifying drugs are approved to date. Thus, PSC management is directed against symptoms and complications and includes medical therapies for pruritus, endoscopic treatment of biliary stenosis and liver transplant for end-stage liver disease. Other non-immune-mediated hepatobiliary disorders are gallstone disease, whose incidence is higher in IBD and reported in up to one third of IBD patients, non-alcoholic fatty liver disease, pyogenic liver abscess and portal vein thrombosis. Drug-induced liver injury (DILI) is an important issue in IBD, since most IBD therapies may cause liver toxicity; however, the incidence of serious adverse events is low. Thiopurines and methotrexate are the most associated with DILI, while the risk related to anti-tumor necrosis factor-α and anti-integrins is low. Data on hepatotoxicity of newer drugs approved for IBD, like anti-interleukin 12/23 and tofacitinib, are still scarce, but the evidence from other rheumatic diseases is reassuring. Hepatitis B reactivation during immunosuppressive therapy is a major concern in IBD, and adequate screening and vaccination is warranted. On the other hand, hepatitis C reactivation does not seem to be a real risk, and hepatitis C antiviral treatment does not influence IBD natural history. The approach to an IBD patient with abnormal liver function tests is complex due to the wide range of differential diagnosis, but it is of paramount importance to make a quick and accurate diagnosis, as it may influence the therapeutic management.

Tackling the Threat of Cancer Due to Pathobionts Producing Colibactin: Is Mesalamine the Magic Bullet?

Colibactin is a genotoxin produced primarily by Escherichia coli harboring the genomic pks island (pks⁺ E. coli). Pks⁺ E. coli cause host cell DNA damage, leading to chromosomal instability and gene mutations. The signature of colibactin-induced mutations has been described and found in human colorectal cancer (CRC) genomes. An inflamed intestinal environment drives the expansion of pks⁺ E. coli and promotes tumorigenesis. Mesalamine (i.e., 5-aminosalycilic acid), an effective anti-inflammatory drug, is an inhibitor of the bacterial polyphosphate kinase (PPK). This drug not only inhibits the production of intestinal inflammatory mediators and the proliferation of CRC cells, but also limits the abundance of E. coli in the gut microbiota and diminishes the production of colibactin. Here, we describe the link between intestinal inflammation and colorectal cancer induced by pks⁺ E. coli. We discuss the potential mechanisms of the pleiotropic role of mesalamine in treating both inflammatory bowel diseases and reducing the risk of CRC due to pks⁺ E. coli.

Real-world experience with MMX mesalazine use in Mexican patients with ulcerative colitis at two tertiary care centers

INTRODUCTION AND AIMS

The 5-aminosalicylates, especially mesalazine, are the first option in the treatment of mild-to-moderate ulcerative colitis (UC). High rates of remission induction and maintenance have been observed with the new multimatrix (MMX) mesalazine formulation, mainly in patients with distal disease. Our aim was to describe the real-world experience with MMX mesalazine in patients with UC at two tertiary care centers.

MATERIALS AND METHODS

A retrospective cohort study was conducted that included 142 patients with confirmed UC diagnosis, analyzed in three study groups: 1) oral MMX mesalazine as monotherapy for remission induction, 2) oral MMX mesalazine as monotherapy for remission maintenance, and 3) oral MMX mesalazine plus topical therapy for remission induction.

RESULTS

The frequency of clinical remission induction in group 1 was 80.3%, with biochemical remission of 74.2%. Group 2 had 100% clinical and biochemical remission maintenance. The frequency of clinical remission induction in group 3 was 88.6%, biochemical remission was 85.7%, and topical therapy was suspended in 87.3% at the end of follow-up. No adverse events were documented.

CONCLUSIONS

There were high percentages of clinical and biochemical remission in the two corresponding study groups and topical therapy was suspended in the majority of patients in ashort follow-up period.

Efficacy and safety of oral Pentasa (prolonged-release mesalazine) in mild-to-moderate ulcerative colitis: a systematic review and meta-analysis

BACKGROUND

Pentasa (prolonged-release mesalazine [5-ASA]) has been available for >30 years as an effective treatment for mild-to-moderate ulcerative colitis (UC). A systematic literature review and meta-analysis was undertaken to provide an up-to-date evaluation of oral Pentasa efficacy and safety for induction and maintenance of remission.

METHODS

Literature searches were conducted in PubMed, Embase and Cochrane databases, from inception to 02 December 2020. Unpublished studies were also sourced. Meta-analyses using a random-effects model and Bayesian inference compared Pentasa (tablets, granules, capsules) against placebo and other 5-ASAs.

RESULTS

Twelve studies involving 3674 patients treated with Pentasa were identified. Pentasa 2-4 g/day was superior to placebo at inducing (absolute risk difference [ARD] at 8 weeks 0.14, 95% CI 0.07‒0.21; p < .001) and maintaining (ARD 6-12 months 0.18, 95% CI 0.04‒0.33; p < .05) remission (clinical/endoscopic). Against other 5-ASAs, Pentasa had similar efficacy for induction (ARD <0.001, 95% CI -0.05‒0.05) and maintenance (ARD 0.01, 95% CI -0.07‒0.08) treatment using randomized controlled trial data. Upon inclusion of real-world study data, Pentasa was significantly better at maintaining remission compared both to Eudragit-S mesalazine and sulfasalazine (ARD 0.04, 95% CI 0.02‒0.06; p < .001). Pentasa (1-4 g/day) had similar treatment-related adverse event rates to placebo (ARD 0.02, 95% CI -0.03‒0.06) and Eudragit-L/S mesalazines (2.25-3 vs 2.4-3 g/day, respectively; ARD -0.03, 95% CI -0.12‒0.05), but was better tolerated than sulfasalazine (3 g/day) (ARD 0.07, 95% CI 0.003‒0.14; p < .05).

CONCLUSION

This study confirms oral Pentasa is efficacious and well-tolerated in treating active UC and maintaining remission. The availability of multiple forms of Pentasa supports physicians' ability to individualize treatment and optimize dosing to improve outcomes.

Effect of MicroRNA145 on the multidrug resistance gene of ulcerative colitis in rats

Multidrug resistance gene (MDR1a) and P-glycoprotein (P-gp) play an important role in the development of ulcerative colitis (UC) and influence the therapeutic effect of glucocorticoids, which may lead to drug resistance mechanically. UC may be related to miR-145 to some extent, and the relationship still needs further exploration. In this study we found that the expression of miR-145 was downregulated in the colonic tissues of rats with Dextran sodium sulfate (DSS)-induced UC. Also, the expression of MDR1a in colon tissues of each group negatively correlated with the expression of miR-145 in rats. The change in the plasma peak concentration (Cmax) in each group positively related to the miR-145 level. Mechanistically, miR-145 negatively regulated the expression and function of P-gp via acting directly on the 3'-UTR of MDR1 mRNA. Overall, these results indicated that miR-145 had a protective effect on the colorectal mucosa, and its downregulation may enhance the expression and function of MDR1a and P-gp, promoting the occurrence and development of UC. The downregulation of miR-145 reduced the drug sensitivity of 5-aminosalicylic acid (5-ASA) and glucocorticoids in treating UC, indicating that miR-145 might be a potential therapeutic target for UC.

Mesalazine and inflammatory bowel disease - From well-established therapies to progress beyond the state of the art

Inflammatory bowel disease incidence has been constantly rising for the past few decades. Current therapies attempt to mitigate its symptoms since no cure is established. The most commonly prescribed drug for these patients is 5-aminosalicylic acid (5-ASA). Due to the low rate and seriousness of side effects compared to other therapies, 5-ASA is still largely prescribed in many stages of inflammatory bowel disease, including scenarios where evidence suggests low effectiveness. Although commercialized formulations have come a long way in improving pharmacokinetics, it is still necessary to design and develop novel delivery systems capable of increasing effectiveness at different stages of the disease. In particular, micro- and nano-sized particles might be the key to its success in Crohn's disease and in more serious disease stages. This review provides an overview on the clinical significance of 5-ASA formulations, its limitations, challenges, and the most recent micro- and nanoparticle delivery systems being designed for its controlled release. Emergent alternatives for 5-ASA are also discussed, as well as the future prospects for its application in inflammatory bowel disease therapies.

Efficacy of Oral, Topical, or Combined Oral and Topical 5-Aminosalicylates, in Ulcerative Colitis: Systematic Review and Network Meta-analysis

BACKGROUND

5-Aminosalicylates [5-ASAs] are the mainstay of treatment for ulcerative colitis [UC]. The optimum preparation, dose, and route of administration for UC remain unclear. We conducted a network meta-analysis to examine this issue.

METHODS

We searched MEDLINE, EMBASE, EMBASE Classic, and the Cochrane central register of controlled trials from inception to December 2020. We included randomised controlled trials [RCTs] comparing oral, topical, or combined oral and topical 5-ASAs, with each other or placebo for induction of remission or prevention of relapse of UC. Results were reported as pooled relative risks [RRs] with 95% confidence intervals [CIs] to summarise effect of each comparison tested, with treatments ranked according to P-score.

RESULTS

We identified 40 RCTs for induction of remission and 23 for prevention of relapse. Topical mesalazine [P-score 0.99], or oral and topical mesalazine combined [P-score 0.87] ranked first and second for clinical and endoscopic remission combined. Combined therapy ranked first in trials where ≥50% of patients had left-sided/extensive disease, and topical mesalazine first in trials where ≥50% of patients had proctitis/proctosigmoiditis. High-dose [≥3.3 g/day] oral mesalazine ranked third in most analyses, with the most trials and most patients. For relapse of disease activity, combined therapy and high-dose oral mesalazine ranked first and second, with topical mesalazine third. 5-ASAs were safe and well tolerated, regardless of regimen.

CONCLUSIONS

Our results support previous evidence; however, higher doses of oral mesalazine had more evidence for induction of remission than combined therapy and were significantly more efficacious than lower doses. Future RCTs should better establish the role of combined therapy for induction of remission, as well as optimal doses of oral 5-ASAs to prevent relapse.

Real-world experience with MMX mesalazine use in Mexican patients with ulcerative colitis at two tertiary care centers

INTRODUCTION AND AIMS

The 5-aminosalicylates, especially mesalazine, are the first option in the treatment of mild-to-moderate ulcerative colitis (UC). High rates of remission induction and maintenance have been observed with the new multimatrix (MMX) mesalazine formulation, mainly in patients with distal disease. Our aim was to describe the real-world experience with MMX mesalazine in patients with UC at two tertiary care centers.

MATERIALS AND METHODS

A retrospective cohort study was conducted that included 142 patients with confirmed UC diagnosis, analyzed in three study groups: 1) oral MMX mesalazine as monotherapy for remission induction, 2) oral MMX mesalazine as monotherapy for remission maintenance, and 3) oral MMX mesalazine plus topical therapy for remission induction.

RESULTS

The frequency of clinical remission induction in group 1 was 80.3%, with biochemical remission of 74.2%. Group 2 had 100% clinical and biochemical remission maintenance. The frequency of clinical remission induction in group 3 was 88.6%, biochemical remission was 85.7%, and topical therapy was suspended in 87.3% at the end of follow-up. No adverse events were documented.

CONCLUSIONS

There were high percentages of clinical and biochemical remission in the two corresponding study groups and topical therapy was suspended in the majority of patients in a short follow-up period.

Glucocorticoid Therapy in Inflammatory Bowel Disease: Mechanisms and Clinical Practice

Inflammatory bowel disease (IBD) comprises ulcerative colitis (UC) and Crohn's disease (CD). IBD etiopathology is multifactorial and involves alteration of immune cells and chronic activation of the inflammatory cascade against yet unknown environmental factors that trigger the disease. IBD therapy aims at improving the quality of life and reducing the risk of disease-related complications to avoid the need for surgery. There is no specific cure for IBDs, and the focus of therapy is supportive measures and use of anti-inflammatory and immunosuppressive drugs. Glucocorticoids (GCs) are powerful anti-inflammatory and immunomodulatory agents used to treat many acute and chronic inflammatory diseases. GCs remain basic treatment for moderate-to-severe IBD, but their use is limited by several important adverse drug effects. Topical administration of a second-generation of GCs, such as budesonide and beclomethasone dipropionate (BDP), represents a valid alternative to use of older, systemic GCs. Administration of second-generation GCs shows promisingly high topical activity and less systemic toxicity, but maintenance therapy with these new GCs in IBD patients is associated with multiple adverse effects. In this review, we make a comparative analysis of the efficacy of first-generation and second-generation GCs in IBD treatment. Unraveling GC biology at the molecular level to uncouple their clinical benefits from detrimental effects is important. One approach is to consider new GC mediators, such as glucocorticoid-induced leucine zipper, which may have similar anti-inflammatory properties, but avoids the side effects of GCs. This in-depth analysis can help to improve the development and the clinical outcomes of GC therapies in IBD.

The Effect of Thermal-Treating on Drug Release from Sustained Release Alginate-Eudragit RS Matrices

Purpose: The main objective of the present study was to develop the colonic delivery system for 5-aminosalicylic acid (5-ASA) as an anti-inflammatory drug.

Methods: Matrix pellets containing various proportions of alginate, calcium and Eudragit^® RS were prepared by extrusion-spheronization technique. Thermal treatment was used to investigate the effect of the curing process on the surface morphology, mechanical and physicochemical properties and in vitro drug release profile of pellets. Based on the obtained results optimal formulations were selected to coating by the Eudragit^® RS and subjected to a subsequent continuous dissolution test.

Results: Image analysis and also scanning electron microscopy results proved acceptable morphology of the pellets. The fourier transform infrared spectroscopy and differential scanning calorimetry studies ruled out any interactions between the formulation’s components. Curing process did not alter the mechanical properties of pellets. The release rate of the drug from matrices was prolonged due to the decreased porosity of cured pellets. Furthermore, selected cured pellets which coated with Eudragit^® RS, prevented undesired premature drug release.

Conclusion: Formulation containing 17.5% calcium, 17.5% alginate, and a coating level of 10% demonstrated enhanced drug release so that provided resistance to acidic conditions, allowing complete drug release in alkaline pH, mimicking colonic environment. The slow and consistent drug release from this formulation could be used for treatment of a broader range of Inflammatory bowel disease (IBD) patients especially in whom colonic pH levels have been measured at lower than pH 7.0.

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.