Rectal and colonic mesalazine concentration in ulcerative colitis: oral vs. oral plus topical treatment

Endoplasmic Reticular Stress and Pathogenesis of Experimental Colitis: Mechanism of Action of 5-Amino Salicylic Acid

OBJECTIVES

Inflammatory bowel diseases which are characterized by endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) signaling pathway are commonly treated with 5-amino salicylic acid (5-ASA). The objective of this study was to investigate the role of 5-amino salicylic acid in the UPR-signaling pathway in experimental colitis.

MATERIALS AND METHODS

Colitis was induced in male Sprague-Dawley rats by intrarectal instillation of trinitrobenzene sulfonic acid. Animals received 5-amino salicylic acid (100 mg/kg body weight) 2 h before the induction of colitis and repeated daily until day 7. The animals were sacrificed on day 7 and tissues were collected for analysis.

RESULTS

The expression of protein kinase R (PKR)-like ER kinase (PERK), a mediator of UPR signaling increased significantly (p < 0.05), while inositol-requiring enzyme type-1 (IRE1) and the CCAAT/enhancer-binding homologous protein (CHOP) remained unaltered in the inflamed colon. The expression of glucose-regulated protein-78, activator of transcription factor-4, and phosphorylated-eukaryotic initiation factor-2α (eIF2αP) increased (p < 0.05) in the inflamed colon. However, the levels of eIF2α protein and mRNA expression remained unchanged. Myeloperoxidase activity, colon weight, and infiltration of inflammatory cells increased significantly (p < 0.05) in the submucosa whereas the body weight decreased. These changes were significantly inhibited by 5-amino salicylate treatment.

CONCLUSION

These findings suggest that the anti-inflammatory properties of 5-amino salicylic acid are mediated through the inhibition of the PERK signaling pathway.

OBJECTIVES

Inflammatory bowel diseases which are characterized by endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) signaling pathway are commonly treated with 5-amino salicylic acid (5-ASA). The objective of this study was to investigate the role of 5-amino salicylic acid in the UPR-signaling pathway in experimental colitis.

MATERIALS AND METHODS

Colitis was induced in male Sprague-Dawley rats by intrarectal instillation of trinitrobenzene sulfonic acid. Animals received 5-amino salicylic acid (100 mg/kg body weight) 2 h before the induction of colitis and repeated daily until day 7. The animals were sacrificed on day 7 and tissues were collected for analysis.

RESULTS

The expression of protein kinase R (PKR)-like ER kinase (PERK), a mediator of UPR signaling increased significantly (p < 0.05), while inositol-requiring enzyme type-1 (IRE1) and the CCAAT/enhancer-binding homologous protein (CHOP) remained unaltered in the inflamed colon. The expression of glucose-regulated protein-78, activator of transcription factor-4, and phosphorylated-eukaryotic initiation factor-2α (eIF2αP) increased (p < 0.05) in the inflamed colon. However, the levels of eIF2α protein and mRNA expression remained unchanged. Myeloperoxidase activity, colon weight, and infiltration of inflammatory cells increased significantly (p < 0.05) in the submucosa whereas the body weight decreased. These changes were significantly inhibited by 5-amino salicylate treatment.

CONCLUSION

These findings suggest that the anti-inflammatory properties of 5-amino salicylic acid are mediated through the inhibition of the PERK signaling pathway.

Common Mistakes in Managing Patients with Inflammatory Bowel Disease

Introduction: Errors are very common in medical practice and in particular, in the healthcare of patients with inflammatory bowel disease (IBD); however, most of these can be prevented. Aim: To address common errors in the management of IBD. Methods: Our approach to this problem consists in identifying mistakes frequently observed in clinical practice (according to our experience) in the management of patients with IBD, then reviewing the scientific evidence available on the subject, and finally proposing the most appropriate recommendation for each case. Results: The most common mistakes in the management of IBD include those related to diagnosis and differential diagnosis, prevention, nutrition and diet, treatment with different drugs (mainly 5-aminosalicylates, corticosteroids, thiopurines, and anti-TNF agents), extraintestinal manifestations, anemia, elderly patients, pregnancy, and surgery. Conclusions: Despite the availability of guidelines for both disease management and preventive aspects of IBD care, a considerable variation in clinical practice still remains. In this review, we have identified common mistakes in the management of patients with IBD in clinical practice. There is a clear need for a greater dissemination of clinical practice guidelines among gastroenterologists and for the implementation of ongoing training activities supported by scientific societies. Finally, it is desirable to follow IBD patients in specialized units, which would undoubtedly be associated with higher-quality healthcare and a lower likelihood of errors in managing these patients.

Management of proctitis in ulcerative colitis and the place of biological therapies

INTRODUCTION

Approximately 20-30% of the patients with ulcerative colitis (UC) may present with isolated proctitis. Ulcerative proctitis (UP) is a challenging condition to manage due to its significant burden in terms of disabling symptoms.

AREAS COVERED

PubMed was searched up to March 2024 to identify relevant studies on UP. A comprehensive summary and critical appraisal of the available data on UP are provided, highlighting emerging treatments and areas for future research.

EXPERT OPINION

Patients with UP are often undertreated, and the disease burden is often underestimated in clinical practice. Treat-to-target management algorithms can be applied to UP, aiming for clinical remission in the short term, and endoscopic remission and maintenance of remission in the long term. During their disease, approximately one-third of UP patients require advanced therapies. Escalation to biologic therapy is required for refractory or steroid dependent UP. For optimal patient care and management of UP, it is necessary to include these patients in future randomized clinical trials.

Clinical Background Factors as Predictors of the Efficacy of 5-Aminosalicylic Acid Suppositories in Patients with Ulcerative Colitis

Introduction

Although the efficacy of 5-aminosalicylic acid (ASA) suppositories for ulcerative colitis (UC) has been reported in many studies, many studies have also described poor adherence to 5-ASA suppository regimens. We aimed to identify the clinical background factors that influence adherence to 5-ASA suppositories to improve adherence and efficacy of the treatment.

Methods

We conducted a retrospective cohort study of 61 patients with active UC who were using 5-ASA suppositories. All patients underwent endoscopy and rectal biopsy for histological diagnosis prior to 5-ASA suppository treatment. The efficacy of 5-ASA suppository treatment was compared in relation to clinical background factors (sex, age, disease duration, disease type, clinical activity, Ulcerative Colitis Endoscopic Index of Severity, histological activity, serum C-reactive protein level, concomitant use of immunomodulators, history of steroid use, and dose of oral 5-ASA).

Results

The efficacy of 5-ASA suppositories was significantly related to low Lichtiger Colitis Activity Index (LCAI) scores and proctitis type prior to its use. In terms of sex, females tended to show higher efficacy. Multivariate logistic regression analysis using these three factors showed high predictive value for the efficacy of 5-ASA suppositories (AUC, 0.788; sensitivity, 87.2%; and specificity, 63.7%).

Conclusion

This study is the first to extract clinical background factors for predicting the efficacy of 5-ASA suppositories. The use of 5-ASA suppositories in patients who are expected to show efficacy will be effective in improving patient co-operation.

When disease extent is not always a key parameter: Management of refractory ulcerative proctitis

Background

Patients with ulcerative proctitis represent a sub-group of ulcerative colitis patients with specific characteristics. Disease-related symptoms, endoscopic findings and patient's personality perspectives create a difficult-to-assess condition in certain cases.

Objectives

To summarize available evidence on the management of refractory ulcerative proctitis and provide insights in treatment options.

Results

/Conclusion: Topical therapy plays a central role due to the location of the disease. However, well-established treatment options may become exhausted in a considerable proportion of ulcerative proctitis patients, indicating the need to advance to more potent therapies in order to induce and maintain clinical response and remission in these refractory cases. Systemic corticosteroids, thiopurines, calcineurin inhibitors, biologic agents and small molecules have all been tested with variable success rates. Investigational interventions as well as surgical procedures are kept as the ultimate resort in multi-treatment resistant cases. Identifying early prognostic factors that herald a disabling disease progression will help in optimizing treatment and avoiding surgery.

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.

Clinical Pharmacokinetic and Pharmacodynamic Considerations in the Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) of unknown etiology, probably caused by a combination of genetic and environmental factors. The treatment of patients with active UC depends on the severity, localization and history of IBD medication. According to the classic step-up approach, treatment with 5-aminosalicylic acid compounds is the first step in the treatment of mild to moderately active UC. Corticosteroids, such as prednisolone are used in UC patients with moderate to severe disease activity, but only for remission induction therapy because of side effects associated with long-term use. Thiopurines are the next step in the treatment of active UC but monotherapy during induction therapy in UC patients is not preferred because of their slow onset. Therapeutic drug monitoring (TDM) of the pharmacologically active metabolites of thiopurines, 6-thioguanine nucleotide (6-TGN), has proven to be beneficial. Thiopurine S-methyltransferase (TMPT) plays a role in the metabolic conversion pathway of thiopurines and exhibits genetic polymorphism; however, the clinical benefit and relevance of TPMT genotyping is not well established. In patients with severely active UC refractory to corticosteroids, calcineurin inhibitors such as ciclosporin A (CsA) and tacrolimus are potential therapeutic options. These agents usually have a rather rapid onset of action. Monoclonal antibodies (anti-tumor necrosis factor [TNF] agents, vedolizumab) are the last pharmacotherapeutic option for UC patients before surgery becomes inevitable. Body weight, albumin status and antidrug antibodies contribute to the variability in the pharmacokinetics of anti-TNF agents. Additionally, the use of concomitant immunomodulators (thiopurines/methotrexate) lowers the rate of immunogenicity, and therefore the concomitant use of anti-TNF therapy with an immunomodulator may confer some advantage compared with monotherapy in certain patients. TDM of anti-TNF agents could be beneficial in patients with primary nonresponse and secondary loss of response. The potential benefit of applying TDM during vedolizumab treatment has yet to be determined.

Real-World Data on Topical Therapies and Annual Health Resource Utilization in Hospitalized Swiss Patients with Ulcerative Colitis

Objectives

Topical treatment with aminosalicylates and/or budesonide was shown to be highly effective in patients with ulcerative colitis (UC), while reducing the likelihood of systemic adverse effects. However, previous research has shown that topical treatment is clearly underused. We aimed to evaluate the use of topical therapy in the real-world setting.

Methods

This is an observational study based on claims data of 201 Swiss adult patients who were hospitalized for UC between 2012 and 2014 and who were then followed for 1 year. A variety of factors presumably associated with topical treatment were examined. Annual health care utilization (UC-related medications, diagnostic procedures, consultations, and rehospitalizations) of patients with versus without topical therapy was compared.

Results

Of the 201 hospitalized UC patients, 82 (40.8%) were treated with topical 5-acetylsalicylic acid (ASA) and/or topical rectal steroids. The main factors significantly and positively associated with receiving topical treatment were the use of topical treatment in the year prior to the hospitalization, receiving oral 5-ASA, and living in an urban area. The mode of administration was further related to the language area. Patients with topical therapy significantly more often received other UC-related medications, such as combinations with systemic steroids. They significantly more often underwent colonoscopies and calprotectin measurements, and more often consulted a gastroenterologist in the follow-up, while there was no significant difference regarding rehospitalizations.

Conclusions

Topical treatment is underused in patients with UC, which stands in contrast to the current European Crohn's and Colitis Organization guidelines. Patients' preferences and considerations need to be taken into account when prescribing medical therapy.

Mucosal 5-aminosalicylic acid concentration, drug formulation and mucosal microbiome in patients with quiescent ulcerative colitis

BACKGROUND

5-aminosalicylic acid (5-ASA) is the first-line therapy for ulcerative colitis (UC). 5-ASA acts locally in the colonic mucosa by numerous proposed mechanisms, and is metabolised by N-acetyltransferase (NAT). Large variations in mucosal 5-ASA concentrations have been reported, but the underlying mechanisms are not understood.

AIM

To study the relationship between 5-ASA concentration, 5-ASA formulation, NAT genotype and bacterial microbiome in patients with UC.

METHODS

Patients with quiescent UC, using monotherapy of Mezavant (n = 18), Asacol (n = 14) or Pentasa (n = 10), 4.0-4.8 g/day were included. 5-ASA was measured in colonic mucosal biopsies and serum by ultra-high performance liquid chromatography. NAT genotypes were determined by Sanger sequencing. Bacterial microbiome was sequenced from faeces and mucosa by 16S rRNA sequencing using Illumina Miseq.

RESULTS

Mezavant provided the highest mucosal 5-ASA levels (geometric mean 2.39 ng/mg), followed by Asacol (1.60 ng/mg, 33% lower, P = 0.50) and Pentasa (0.57 ng/mg, 76% lower, P = 0.033). Mucosal 5-ASA concentration was not associated with NAT genotype, but serum 5-ASA concentration and NAT1 genotype was associated (P = 0.044). Mucosal 5-ASA concentration was positively associated with mucosal bacterial diversity (P = 0.0005) and bacterial composition. High mucosal 5-ASA concentration was related to reduced abundance of pathogenic bacteria such as Proteobacteria, and increased abundance of several favourable bacteria such as Faecalibacterium.

CONCLUSIONS

Mucosal 5-ASA concentration is positively associated with bacterial diversity and a mucosal bacterial composition that are perceived favourable in UC. Mezavant yielded higher mucosal 5-ASA concentrations than Pentasa. 5-ASA may have beneficial effects on the mucosal microbiome, and high concentrations possibly amend dysbiosis in UC.

Influence of Pharmaceutical Formulation on the Mucosal Concentration of 5-Aminosalicylic Acid and N-Acetylmesalamine in Japanese Patients with Ulcerative Colitis

The efficacy of 5-aminosalicylic acid (5-ASA) as the first-line therapy for ulcerative colitis (UC) is determined by the extent of drug delivery to the inflamed region. Moreover, differences among the various formulations influence delivery of the drug. In this study, we examined the clinical significance of colonic mucosal concentrations of 5-ASA and N-acetylmesalamine (Ac-5-ASA) in UC patients receiving a pH-dependent or time-dependent release formulation of 5-ASA. The subjects were 67 patients with UC who were treated with a pH-dependent or time-dependent formulation of 5-ASA between December 2011 and April 2014. A retrospective observational analysis of clinical outcomes was performed using the clinical activity index (CAI) obtained on the day of biopsy. Colonic mucosal concentrations of 5-ASA and Ac-5-ASA in biopsy samples were measured by LC-tandem mass spectrometry/mass spectrometry. Patients who were treated with the pH-dependent formulation had higher colon mucosal concentrations of 5-ASA than those who were treated with the time-dependent formulation. Additionally, 5-ASA concentration was significantly higher in patients with CAI scores ≤3. A higher concentration of Ac-5-ASA was achieved with the time-dependent formulation than with the pH-dependent formulation. Furthermore, patients with CAI scores ≤3 had higher concentrations of 5-ASA than those with CAI scores ≥4. The colonic mucosal concentration of 5-ASA in patients with UC is influenced by the pharmaceutical formulation and the remission status of UC.

Therapeutic requirements in active ulcerative proctitis: A single-centre study

BACKGROUND

Ulcerative proctitis (UP) presents distinctive clinical characteristics, outcomes and therapeutic approaches as compared to left-sided and extensive ulcerative colitis (UC).

AIM

To describe the current therapeutic requirements and clinical outcomes in patients with active UP.

METHODS

Retrospective observational study conducted in a referral IBD centre. Patients with UP in follow-up between 1989 and 2014 were included. The clinical characteristics, as well as the different treatments and drug formulations administered to treat flares, were recorded.

RESULTS

Out of 687 UC patients, 101 patients (15%) with UP were included. Median follow-up was 8 years (IQR 3-14) and 49% of patients presented disease activity during the study period. Topical mesalazine monotherapy (90%) was the most commonly administered treatment for disease activity (mostly as suppositories), followed by topical steroids (47%) and oral mesalazine (56%) in monotherapy or combination therapy. Only 14% and 16% of patients required oral prednisone and beclomethasone, respectively.

CONCLUSIONS

In clinical practice, active UP presents mostly favourable outcomes. Mesalazine suppositories are by far the most used treatment for these patients.

Total and cancer mortality in a cohort of ulcerative colitis and Crohn's disease patients: The Florence inflammatory bowel disease study, 1978-2010

BACKGROUND

There is no consensus on the leading causes of death among inflammatory bowel diseases (IBD) patients.

AIM

We present the results of an extended follow-up of the population-based Florence IBD cohort, including 689 ulcerative colitis and 231 Crohn's disease patients.

METHODS

The causes of death of cohort members were determined through linkage with the local mortality registry. We calculated standardized mortality ratios (SMR) and 95% confidence intervals (95%CI) by applying gender-, age- and calendar time-death rates to person-years at risk.

RESULTS

Ulcerative colitis patients had overall mortality comparable to the general population (SMR 0.99, 95%CI 0.85-1.14), though being at increased risk of dying from Hodgkin's disease (SMR 11.74, 95%CI 2.94-46.94), rectal cancer (SMR 3.69, 95%CI 1.66-8.22) and Alzheimer's disease (2.40, 95%CI 1.00-5.76). Crohn's disease patients had an increased overall mortality (SMR 1.79, 95%CI 1.39-2.27) and were at higher risk of dying from cancer (SMR 2.57, 95%CI 1.28-5.13) and non-cancer diseases of the respiratory system (SMR 2.51, 95%CI 1.05-6.04), brain cancer (SMR 6.26, 95%CI 1.57-25.02) and non-cancer diseases of the genitourinary system (SMR 4.38, 95%CI 1.10-17.52).

CONCLUSIONS

IBD patients should be offered counselling on risk reduction strategies, as much of their mortality excess is potentially avoidable.

Nanotechnology in the treatment of inflammatory bowel diseases

BACKGROUND AND AIMS

Treatment of inflammatory bowel diseases (IBD) is only aimed to block or inhibit the pathogenetic steps of the inflammatory cascade. Side effects of systemic therapies, poor targeting of orally administered topical drug and low adherence to prescription represent frequent therapeutic challenges. Recent observations suggest that nanotechnology could provide amazing advantage in this field since particles having dimension in the nanometer scale (nanoparticles) can modify pharmacokinetic step of biologic and conventional therapeutic agents with a better delivery of drugs within the intestinal inflammatory cells. The aim of this review was to provide the clinician with an insight into the potential role of nanotechnology in the treatment of IBD.

METHODS

A systematic search (PubMed) for experimental studies on the treatment of intestinal inflammation using nanotechnology for the delivery of drugs.

RESULTS AND CONCLUSIONS

The size of the pharmaceutical formulation is inversely related to specificity for inflammation. Nanoparticles can penetrate epithelial and inflammatory cells resulting in much higher, effective and long-acting concentrations than can be obtained using conventional delivery systems. From a practical point of view, this should lead to improvements in both efficacy and adherence to treatment, providing patients with the prospect of stable and prolonged remissions with reduced drug loadings. Reduced systemic side effects could also be expected.

Treatment of ulcerative colitis

PURPOSE OF REVIEW

Ulcerative colitis is a chronic inflammatory disease of the colon of unknown cause that is characterized by alternating intervals of active and inactive disease in 80-90% of patients. The primary goal of treatment is to induce and maintain remission using therapy tailored to the individual patient. The purpose of this review was to describe the management of ulcerative colitis with emphasis on the use of anti-tumor necrosis factor (TNF) agents.

RECENT FINDINGS

Recent research has shown that new anti-TNF agents, adalimumab (ADA) and golimumab, are effective in induction of remission and maintenance of remission in patients with extensive ulcerative colitis. In a recent study, infliximab was found to have comparable efficacy to cyclosporine in treatment of acute severe refractory to corticosteroids ulcerative colitis.

SUMMARY

Anti-TNF therapy should be initiated in patients with acute severe refractory to corticosteroids ulcerative colitis and in patients with moderate-to-severe ulcerative colitis who are not responsive to conventional treatment with aminosalicylates, corticosteroids and immune modulators. Alternatives to infliximab are ADA and golimumab. Future research is needed to further assess the long-term efficacy and safety of ADA and golimumab in ulcerative colitis.

5-ASA colonic mucosal concentrations resulting from different pharmaceutical formulations in ulcerative colitis

AIM: To compare the mucosal concentrations of 5-aminosalicylic acid (5-ASA) resulting from different pharmaceutical formulations and analyse the influence of inflammation on the mucosal concentrations.

METHODS: The study included 130 inflammatory bowel disease (IBD) patients receiving 5-ASA as pH-dependent-release formulations (73 patients), time-dependent-release formulations (11 patients), or pro-drugs (18 patients). In addition, 28 patients were receiving topical treatment (2-4 g/d) with pH-dependent-release formulations. Endoscopic biopsies were obtained from the sigmoid region during the colonoscopy. The 5-ASA concentrations (ng/mg) were measured in tissue homogenates using high-pressure liquid chromatography with electrochemical detection. The t test and Mann-Whitney test, when appropriate, were used for statistical analysis.

RESULTS: Patients receiving pH-dependent-release formulations showed significantly higher mucosal concentrations of 5-ASA (51.75 ± 5.72 ng/mg) compared with patients receiving pro-drugs (33.35 ± 5.78 ng/mg, P = 0.01) or time-dependent-release formulations (38.24 ± 5.53 ng/mg, P = 0.04). Patients with endoscopic remission had significantly higher mucosal concentrations of 5-ASA than patients with active disease (60.14 ± 7.95 ng/mg vs 35.66 ± 5.68 ng/mg, P = 0.02). Similar results were obtained when we compared patients with the histological appearance of remission and patients with active histological inflammation (67.53 ± 9.22 ng/mg vs 35.53 ± 5.63 ng/mg, P < 0.001). Significantly higher mucosal concentrations of 5-ASA were detected in patients treated with both oral and topical treatments in combination compared with patients who received oral treatment with pH-dependent-release formulations alone (72.33 ± 11.23 ng/mg vs 51.75 ± 5.72 ng/mg, P = 0.03).

CONCLUSION: IBD patients showed significant variability in mucosal 5-ASA concentrations depending on the type of formulation, and the highest mean concentration was achieved using pH-dependent-release formulations.

Drug advances in inflammatory bowel disease

The pathogenesis of inflammatory bowel disease (IBD) remains incompletely understood, but is thought to be a consequence of immune dysregulation, impaired mucosal integrity, enteric bacterial dysbiosis and genetic susceptibility factors. Recent drug advances in the treatment of IBD have clarified the role of existing medication, including 5-amino-salicylic acids (5-ASAs) and has seen a burgeoning use of treatment with biologicals. With recent advances in our understanding of these debilitating diseases, it is hoped that novel therapeutic targets can be identified.

The 5-aminosalicylic acid antineoplastic effect in the intestine is mediated by PPARγ

Epidemiological evidences suggested that 5-aminosalicylic acid (5-ASA) therapy may prevent the development of colorectal cancer in inflammatory bowel disease patients. Our aim is to investigate whether peroxisome proliferator-activated receptor-γ (PPARγ) mediates the antineoplastic effects of 5-ASA. HT-29 and Caco-2 cells were treated by 5-ASA, rosiglitazone (PPARγ ligand) or etoposide (anticarcinogenic drug). Epithelial cell growth, proliferation and apoptosis were assessed by cell count, Ki-67 staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, respectively. The antineoplastic effect of 5-ASA was evaluated in a xenograft tumor model in SCID mice and in azoxymethane (AOM)-induced colon carcinogenesis in A/JOlaHsd mice. The role of PPARγ was examined by administration of PPARγ antagonist, GW9662 and in PPAR knockdown cells. Compared with untreated cells, treatment of HT-29 cells by 5-ASA inhibited significantly cell growth and cell proliferation (respectively, 60% and 63%) and induced apoptosis in 75% of cells. These effects were abolished by co-treatment with GW9662 and blunted in PPAR knockdown cells. Contrarily to etoposide, similar inhibitory effects of GW9662 were obtained in HT-29 cells treated with rosiglitazone. In the xenograft model, GW9662 abolished the therapeutic effect of 5-ASA, which decreased tumor weight and volume by 80% in SCID mice compared with untreated mice. In A/JOlaHsd mice, 5-ASA suppressed colon carcinogenesis by decreasing the number of aberrant crypt foci (75%) and aberrant crypts (22%) induced by AOM treatment with an absence of 5-ASA response after GW9662 administration. In conclusion, 5-ASA exerts potent antineoplastic effects that are mediated through PPARγ. These data provide new rational for designing more effective and safe antineoplastic PPARγ ligands with topical effects.

Recent developments in the treatment of inflammatory bowel disease

Crohn's disease and ulcerative colitis are chronic inflammatory bowel diseases that have been treated with corticosteroids, 5-aminosalicates and thiopurines, but therapeutic options have been broadened with the arrival of anti-tumor necrosis factor antibodies. In this article we reviewed the current evidence-based approach to inflammatory bowel disease, the modifications that have been made to existing therapies and discussed new drugs that have shown success in clinical trials. The new drugs discussed here are those that disturb lymphocyte homing to the gut (natalizumab, vedolizumab and anti-mucosal addressin cellular adhesion molecule); one that blocks interleukin (IL)-12 as well as the IL-23/T helper 17 (Th17) axis (ustekinumab) and one that blocks the signaling of multiple cytokines (tofacitinib).

Simulated comparison of topical and oral formulations of 5-aminosalicylate for the treatment of ulcerative colitis

BACKGROUND

5-Aminosalicylate (5-ASA) formulations are approved for the treatment of ulcerative colitis (UC). Determination of the colonic pharmacokinetics of 5-ASA is challenging. A dynamic model of 5-ASA colonic amounts after oral delayed-release 5-ASA (Asacol), oral extended delayed-release 5-ASA (Lialda), 5-ASA enema (Rowasa), foam and suppositories (Canasa) was developed to determine the colonic kinetics of these agents.

METHODS

We created a model with Stella software. Colonic 5-ASA in the right, transverse, descending, sigmoid colon, and rectum were estimated for adults after recommended doses of the above formulations. Simulations of active mild/moderate UC and in remission were performed and compared using Student's t-test for differences in means.

RESULTS

For UC in remission, the highest amounts of 5-ASA were from Asacol in the right and transverse colon (P < 0.01), Lialda in the descending and sigmoid colon (P < 0.01), and Rowasa in the rectum (P < 0.01). For active UC, sigmoid amounts were highest with foam (P < 0.01), and rectal amounts highest with Rowasa (P < 0.01). Differences in rectosigmoid amounts of 5-ASA from enemas and suppositories for UC in remission occurred based on the relationship between the timing of administration relative to the daily bowel movement (P < 0.01).

CONCLUSIONS

Compared to Asacol, Lialda results in higher 5-ASA amounts in the left colon. Asacol with Rowasa provides highest 5-ASA amounts across the entire colon. Higher 5-ASA amounts from topical formulations occur when the insertion occurs soon after the daily bowel movement. This model provides a rationale for further investigation.

2-Methoxy-5-amino-N-hydroxybenzamide, a derivative of mesalamine, inhibits colon cancer cell growth through cyclo-oxygenase-2-dependent and -independent mechanisms

COX-2 (cyclo-oxygenase-2) and PGE₂ (prostaglandin E₂) play a key role in sustaining CRC (colorectal cancer) cell growth and survival. Indeed, the use of agents targeting the COX-2/PGE₂ axis has been associated with a reduction in the development of CRC in both humans and murine models of colon carcinogenesis. In the present study, we investigated whether 2-methoxy-5-amino-N-hydroxybenzamide (herein termed 2-14), a derivative of mesalamine that inhibits CRC cell growth both in vitro and in vivo, negatively regulates COX-2/PGE₂ expression in CRC cells and assessed whether the 2-14-mediated anti-neoplastic effect is strictly dependent on the inhibition of this pathway. Our results show that 2-14 blocks the growth and enhances the death of HT-115, a CRC cell line overexpressing COX-2, and that these effects associate with inhibition of COX-2 but not COX-1. 2-14 also down-regulates TNFα (tumour necrosis factor α)-induced COX-2 in HT-29 cells as well as COX-2/PGE₂ expression in ex vivo cultures of human CRC explants. Similarly, 2-14 reduces COX-2, but not COX-1, in tumoural areas developing in a mouse model of CAC (colitis-associated colon cancer). Finally, we show that 2-14 exhibits in vitro and in vivo anti-mitogenic effects in DLD-1, a COX-deficient CRC cell line. Taken together, these results suggest that 2-14 inhibits CRC cell growth through COX-2-dependent and -independent mechanisms.

Influence of some formulation variables on the optimization of pH-dependent, colon-targeted, sustained-release mesalamine microspheres

The aim of this work was to understand the influence of different formulation variables on the optimization of pH-dependent, colon-targeted, sustained-release mesalamine microspheres prepared by O/O emulsion solvent evaporation method, employing pH-dependent Eudragit S and hydrophobic pH-independent ethylcellulose polymers. Formulation variables studied included concentration of Eudragit S in the internal phase and the ratios between; internal to external phase, drug to Eudragit S and Eudragit S to ethylcellulose to mesalamine. Prepared microspheres were evaluated by carrying out in vitro release studies and determination of particle size, production yield, and encapsulation efficiency. In addition, morphology of microspheres was examined using optical and scanning electron microscopy. Emulsion solvent evaporation method was found to be sensitive to the studied formulation variables. Particle size and encapsulation efficiency increased by increasing Eudragit S concentration in the internal phase, ratio of internal to external phase, and ratio of Eudragit S to the drug. Employing Eudragit S alone in preparation of the microspheres is only successful in forming acid-resistant microspheres with pulsatile release pattern at high pH. Eudragit S and ethylcellulose blend microspheres were able to control release under acidic condition and to extend drug release at high pH. The stability studies carried out at 40°C/75% RH for 6 months proved the stability of the optimized formulation. From the results of this investigation, microencapsulation of mesalamine in microspheres using blend of Eudragit S and ethylcellulose could constitute a promising approach for site-specific and controlled delivery of drug in colon.

Efficacy of oral vs. topical, or combined oral and topical 5-aminosalicylates, in Ulcerative Colitis: systematic review and meta-analysis

OBJECTIVES

Efficacy of 5-aminosalicylic acids (5-ASAs) in ulcerative colitis (UC) has been studied previously in meta-analyses. However, no recent meta-analysis has studied the relative efficacies of differing routes of administration.

METHODS

MEDLINE, EMBASE, and the Cochrane central register of controlled trials were searched (through May 2011). Eligible trials recruited adults with mildly to moderately active UC, or quiescent UC, and compared oral 5-ASAs with either topical 5-ASAs or a combination of oral and topical 5-ASAs. Dichotomous data were pooled to obtain relative risk (RR) of failure to achieve remission in active UC, and RR of relapse of disease activity in quiescent UC, with a 95% confidence interval (CI). The number needed to treat (NNT) was calculated from the reciprocal of the risk difference.

RESULTS

The search identified 3,061 citations, and 12 randomized controlled trials (RCTs) were eligible. Four compared topical with oral 5-ASAs in active UC remission, with an RR of no remission with topical 5-ASAs of 0.82 (95% CI=0.52-1.28). Four trials compared combined with oral 5-ASAs in active UC (RR of no remission=0.65; 95% CI=0.47-0.91; NNT=5). Three RCTs compared intermittent topical with oral 5-ASAs in preventing relapse of quiescent UC (RR=0.64; 95% CI=0.43-0.95; NNT=4), and two compared combined with oral 5-ASAs (RR of relapse=0.48; 95% CI=0.17-1.38).

CONCLUSIONS

Combined 5-ASA therapy appeared superior to oral 5-ASAs for induction of remission of mildly to moderately active UC. Intermittent topical 5-ASAs appeared superior to oral 5-ASAs for preventing relapse of quiescent UC.

Common misconceptions about 5-aminosalicylates and thiopurines in inflammatory bowel disease

Misconceptions are common in the care of patients with inflammatory bowel disease (IBD). In this paper, we state the most commonly found misconceptions in clinical practice and deal with the use of 5-aminosalicylates and thiopurines, to review the related scientific evidence, and make appropriate recommendations. Prevention of errors needs knowledge to avoid making such errors through ignorance. However, the amount of knowledge is increasing so quickly that one new danger is an overabundance of information. IBD is a model of a very complex disease and our goal with this review is to summarize the key evidence for the most common daily clinical problems. With regard to the use of 5-aminosalicylates, the best practice may to be consider abandoning the use of these drugs in patients with small bowel Crohn’ s disease. The combined approach with oral plus topical 5-aminosalicylates should be the first-line therapy in patients with active ulcerative colitis; once-daily treatment should be offered as a first choice regimen due to its better compliance and higher efficacy. With regard to thiopurines, they seem to be as effective in ulcerative colitis as in Crohn’ s disease. Underdosing of thiopurines is a form of undertreatment. Thiopurines should probably be continued indefinitely because their withdrawal is associated with a high risk of relapse. Mercaptopurine is a safe alternative in patients with digestive intolerance or hepatotoxicity due to azathioprine. Finally, thiopurine methyltransferase (TPMT) screening cannot substitute for regular monitoring because the majority of cases of myelotoxicity are not TPMT-related.

Review article: delivery and efficacy of topical 5-aminosalicylic acid (mesalazine) therapy in the treatment of ulcerative colitis

BACKGROUND

The use of topical therapy in the treatment of ulcerative colitis has declined in recent years despite evidence of good efficacy.

AIMS

To review US prescription trends for 5-aminosalicylic acid (5-ASA) since the US approval of Asacol extended-release oral mesalazine (mesalamine) in 1992; to estimate the optimal level of 5-ASA exposure in the distal colon; to determine factors influencing distal colonic exposures; and to compare the effectiveness of different 5-ASA formulations (oral, topical suspension, foam, suppositories) in clinical trials.

METHODS

Review of clinical trials, physiologic studies and prescription trends of various mesalazine formulations for treatment of distal ulcerative colitis.

RESULTS

Between 1992 and 2009, prescriptions for oral mesalazine increased sixfold, whereas topical suspensions declined by 10%. In clinical trials, topical therapy resulted in higher remission and clinical response rates than oral therapy, with trends to earlier improvement. The mucosal concentrations of 5-ASA achieved by topical agents in the distal colon were up to 200-fold higher than those achieved by oral administration alone. Despite active colitis, over 40% of a topically administered 4 g 5-ASA suspension (equal to 1.6 g) reached the sigmoid colon. This likely represents a therapeutic exposure of 5-ASA. Although topical therapies are less convenient than oral medications, treatment algorithms have failed to take into account quality of life improvements resulting from more rapid and complete treatment response.

CONCLUSIONS

Topical mesalazine therapy is superior to oral therapy in distal ulcerative colitis for both therapeutic response and drug delivery. Practice patterns should be re-evaluated in light of this information.

Clinical pharmacology of 5-ASA compounds in inflammatory bowel disease

Mesalamine has been the first-line of therapy in patients with inflammatory bowel disease (IBD) since the 1960s. This article serves as a review of the different 5-aminosalicylic acid compounds, release formulations, use and dosing in the treatment of IBD, in particular ulcerative colitis.

Recent advances in the management of distal ulcerative colitis

The most frequent localization of ulcerative colitis (UC) is the distal colon. In treating patients with active distal UC, efficacy and targeting of the drug to the distal colon are key priorities. Oral and rectal 5-aminosalicylic acid (5-ASA) preparations represent the first line therapy of mild-to-moderate distal UC for both induction and maintenance treatment. It has been reported that many UC patients are not adherent to therapy and that non-compliant patients had a 5-fold risk of experiencing a relapse. These findings led to the introduction of once-daily oral regimens of 5-ASA as better therapeutic options in clinical practice due to improved adherence. New formulations of mesalazine, including the multi-matrix delivery system, and mesalazine granules, which allow once-daily administration, have been developed. They have been demonstrated to be efficacious in inducing and maintaining remission in mild-to-moderate distal UC in large clinical trials. However, existing data for distal UC are rather insufficient to make a comparison between new and classical 5-ASA formulations. It seems that the new formulations are at least as effective as classical oral 5-ASA formulations. Other treatment options, in the case that 5-ASA therapy is not effective, include systemic corticosteroids, thiopurines (azathioprine or 6-mercaptopurine), cyclosporine, infliximab and surgery. The combination of a prompt diagnostic work-up, a correct therapeutic approach and an appropriate follow-up schedule is important in the management of patients with distal UC. This approach can shorten the duration of symptoms, induce a prolonged remission, improve patient’s quality of life, and optimize the use of health resources.

5-aminosalicylic acid interferes in the cell cycle of colorectal cancer cells and induces cell death modes

INTRODUCTION

Epidemiological data suggests that 5-aminosalicylic acid (5-ASA), a nonsteroidal antiinflammatory drug used in the treatment of inflammatory bowel diseases, prevents colorectal cancer development in these patients, although the mechanisms remain incompletely understood.

METHODS AND RESULTS

Here we report that 5-ASA prevents growth of several colorectal cancer cell lines by interfering in the cell cycle, i.e., an S-phase and G2/M phase arrest, dependent on 5-ASA dosage and concentration, together with an increased mitotic index. In addition, prolonged cell cycle arrest by repeated 5-ASA treatment induced apoptosis and caused abnormal spindle organization leading to mitotic catastrophe, another form of cell death.

CONCLUSION

These observations illustrate that 5-ASA has chemopreventive and chemotherapeutic properties.

Mesalazine vanishing time from rectal mucosa following its topical administration

To investigate how long and how much Mesalazine (M) is available inside the rectal mucosa following its topical instillation, in patients (pts) with Ulcerative Colitis (UC). Two rectal biopsies for M concentration were obtained from 45 UC pts in clinical remission and on oral M treatment (OT), before a 4g enema randomly given to consentient pts every day (Group A, 15 pts), every 2 days (Group B, 15 pts) and every 3 days (Group C, 15 pts). Two additional biopsies were taken 1, 2 and 3 days after the last enema in group A, B and C respectively, at least 10 days later. All biopsies were immediately frozen at -80°C for later assay by means of high-performance light chromatography (HPLC). Data were analyzed using Student's t-test. Mean values±standard deviation of M mucosal concentration (ng/mg of tissue) were 1.32±1.41, 56.1±39.2, 9.65±6.60, and 6.39±5.03 in pts receiving OT alone, groups A, B and C, respectively. Values in Group A were statistically higher (p<0.001) than those in Groups B and C while no differences were found between Groups B and C. Values of OT were lower than groups A, B and C. M mucosal concentration rapidly decreases 2 days after a 4g enema, but after three days is still higher than OT alone. These results may provide data which would be useful to plan topical therapy and improve adherence to treatment.

Inhibition of colon carcinogenesis by 2-methoxy-5-amino-N-hydroxybenzamide, a novel derivative of mesalamine

BACKGROUND & AIMS

Mesalamine has been reported to protect against inflammatory bowel disease-related colorectal cancer (CRC), but several drug-related issues have limited its use in chemopreventive programs. We evaluated the antineoplastic properties of mesalamine derivatives using in vitro and in vivo models of CRC.

METHODS

CRC cell proliferation and cell-cycle progression were evaluated by flow cytometry after exposure to mesalamine or mesalamine derivatives. Cyclins, cyclin-dependent kinases, and endoplasmic reticulum stress-related molecules were examined by immunoblotting. The in vivo antineoplastic effect of 2-methoxy-5-amino-N-hydroxybenzamide (2-14) was evaluated in a syngenic, CT26-derived xenograft mouse model of CRC and in the azoxymethane/dextran sulfate sodium-induced mouse model of colitis-associated CRC.

RESULTS

The mesalamine derivative 2-14 was 10-fold more potent than mesalamine in inhibiting CRC cell proliferation. After exposure to 2-14, cyclin D1 expression was reduced and G0/G1 phase cells accumulated. These events were preceded by activation of eukaryotic translation initiation factor 2-alpha kinase 3 (pancreatic endoplasmic reticulum eIF2alpha kinase), phosphorylation of eukaryotic translation initiation factor 2alpha, induction of activating transcription factor 4, and splicing of X-box binding protein 1 messenger RNA, events that define endoplasmic reticulum stress. Silencing of PERK restored cyclin D1 levels, allowing cells to overcome the cell-cycle block induced by 2-14. Mice injected with 2-14 developed fewer CRC xenograft-derived tumors. Moreover, 2-14 injection reduced the development of neoplastic lesions induced by azoxymethane and dextran sulfate sodium in mice.

CONCLUSIONS

The mesalamine derivative 2-14 inhibited CRC cell proliferation in vitro and prevented CRC progression in mouse models.

The long journey of salicylates in ulcerative colitis: The past and the future

The advent of salicylates in the treatment of ulcerative colitis started in 1938 with the discovery of Salazopyrin by Nanna Svartz. This drug offered for the first time a therapeutic chance to patients with ulcerative colitis. In this paper we describe the fascinating history of Salazopyrin and salicylates from the first serendipitous observations to the last randomized clinical trials. Attention was paid to the pharmacokinetics and the mechanism of action of 5-aminosalicylates and, in particular, to the issue of the mucosal concentrations of 5-aminosalicylates and its therapeutic efficacy. Moreover a look at the new oral mesalazine formulations that allow the homogenous distribution of 5-aminosalicylate through all the large bowel was taken. Lastly, the possible use of mesalazine in the prevention of colorectal cancer was reviewed.

Mesalamine suppresses the expression of TC22, a novel tropomyosin isoform associated with colonic neoplasia

Although a protective role for mesalamine against colon cancer in ulcerative colitis has been shown epidemiologically, its molecular mechanism is unknown. We cloned and sequenced a novel human tropomyosin (hTM) isoform, TC22, which is an alternatively spliced variant of normal epithelial hTM isoform 5 (hTM5), identical apart from 25 C-terminal amino acids. TC22 is expressed in 100% of colorectal carcinoma but is not expressed in normal colon epithelial cells. To explore a molecular mechanism of chemoprevention, we examined the effect of mesalamine on TC22 expression using LS180 colon cancer cells. Expression of hTM5 and TC22 was investigated at the protein and gene levels by fluorescence-activated cell sorting and real-time reverse transcription-polymerase chain reaction. Small interference RNA (siRNA) against the TC22 variant were transfected into LS180 colon cancer cells, reducing protein and transcript levels by 45 to 50%. Mesalamine or sulfasalazine (2 mM), but not sulfapyridine, significantly (p < 0.02-0.006) reduced the expression of the TC22 transcript and significantly (p < 0.05 to <0.0002) reduced the expression of TC22 protein in a dose-dependent and reversible manner. Rosiglitazone, a specific peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist, similarly and significantly (p < 0.002) reduced TC22 protein expression. A polymerase chain reaction array of 84 cancer-related genes performed on TC22 siRNA-transfected cells demonstrated a significant (more than two times) change in targets involved in apoptosis, adhesion, angiogenesis, and tissue remodeling. We conclude that mesalamine, sulfasalazine, and rosiglitazone significantly reduced the cellular expression of TC22, implicating PPARgamma in this modulation. Similar suppression of TC22 by siRNA produced gene level changes on several critical carcinogenic pathways. These findings suggest a novel antineoplastic molecular effect of mesalamine.

5-Aminosalicylic acid inhibits TGF-beta1 signalling in colorectal cancer cells

The transforming growth factor-beta (TGF-beta) pathway is an important pathway in the initiation and progression of colorectal cancer. We aimed to determine the effects of 5-aminosalicylic acid (5-ASA) on TGF-beta signalling in colorectal cancer cells in vitro. 5-ASA inhibited TGF-beta1 signalling in HCT116 cells and colonic fibroblasts, as judged by a TGF-beta-specific reporter gene assay, plasminogen activator inhibitor-1 mRNA and protein levels, fibroblast trans-differentiation, Smad3 phosphorylation and nuclear translocation. We conclude that 5-ASA inhibits TGF-beta1 signalling in colorectal cancer cells, and might be a potent adjuvant therapeutic drug, interfering with aberrant TGF-beta signalling in colorectal cancer.

5-Aminosalicylic acid inhibits colitis-associated but not sporadic colorectal neoplasia in a novel conditional Apc mouse model

Genetic predisposition, life-style habits and inflammatory bowel diseases (IBD)-related colitis are a main risk factor for colorectal cancer (CRC). 5-Aminosalicylic acid (5-ASA, mesalazine) is a mainstay therapy in IBD and believed to reduce the risk for developing CRC. We aimed to determine the ability of 5-ASA enemas to inhibit the development of sporadic and colitis-related neoplasia in mice. FabplCre;Apc(15lox/+) mice, which spontaneously develop sporadic colorectal tumours, were treated at 5 weeks of age with 5-ASA or placebo enemas for 3 weeks and examined for colorectal tumourigenesis at 8 weeks of age. Colitis-related tumour development was investigated in these mice by administration of dextran sodium sulphate, inducing intestinal inflammation and accelerating colorectal tumourigenesis, combined with treatment of 5-ASA or placebo enemas during and/or after colitis induction. 5-ASA significantly reduced colitis-accelerated neoplasia development by 50%, from 19.4 +/- 2.7 to 9.4 +/- 2.4 (mean tumour numbers +/- SEM, P = 0.02), in the distal part of the large intestine covered by the enema. 5-ASA was only effective when given during and/or after the intestinal inflammatory period. 5-ASA did not reduce, however, sporadic neoplasia development in the FabplCre;Apc(15lox/+) mice. 5-ASA tended to reduce proliferation of epithelial cells in the colitis-associated colorectal tumours but not in the sporadic colorectal tumours. In conclusion, 5-ASA medication inhibits the development of colitis-associated tumours in FabplCre;Apc(15lox/+) mice when administered during and/or after the induction of inflammation. 5-ASA does not reduce, however, sporadic tumour development in this mouse model.

Review article: 5-aminosalicylate formulations for the treatment of ulcerative colitis--methods of comparing release rates and delivery of 5-aminosalicylate to the colonic mucosa

BACKGROUND

Many oral 5-aminosalicylic acid (5-ASA) formulations are designed to maximize 5-ASA release in the colon where it acts topically on the colonic mucosa. Delayed-release formulations and azo-prodrugs minimize 5-ASA absorption in the upper gastrointestinal (GI) tract.

AIMS

To review methods for assessing 5-ASA release and colonic distribution from oral formulations, and the potential use of this information for guiding clinical decisions.

METHODS

PubMed and recent conference abstracts were searched for articles describing techniques used to assess 5-ASA release from ulcerative colitis (UC) therapies.

RESULTS

In-vitro GI models, although unable to simulate more complex aspects of GI physiology, can provide useful data on 5-ASA release kinetics and bioaccessibility. Gamma-scintigraphy is useful for investigating GI disintegration of different formulations, but may not accurately reflect 5-ASA distribution. Plasma pharmacokinetic studies provide data on systemic exposure, but not on colonic distribution or mucosal uptake. Mucosal biopsies provide direct evidence of colonic distribution and may predict clinical efficacy, but must be interpreted cautiously because of considerable inter-subject variability and other confounding factors.

CONCLUSION

While assessment of 5-ASA release is important, limitations of individual measurement techniques mean that randomized clinical studies in UC patients remain the best guide for dosing and treatment regimen decisions.

MMX mesalazine for the induction of remission of mild-to-moderately active ulcerative colitis: efficacy and tolerability in specific patient subpopulations

BACKGROUND

Two phase III studies have evaluated mesalazine (mesalamine) with MMX (Multi Matrix System) technology in patients with active mild-to-moderate ulcerative colitis.

AIM

To determine the efficacy of MMX mesalazine for the induction of clinical and endoscopic remission in specific subgroups of patients with active, mild-to-moderate ulcerative colitis.

METHODS

Data from two double-blind, placebo-controlled trials were analysed (517 out-patients). Patients were randomized to receive MMX mesalazine [2.4 g/day (once daily or 1.2 g twice daily) or 4.8 g/day (once daily)] or placebo for 8 weeks.

RESULTS

The percentages of patients treated with MMX mesalazine, 2.4 or 4.8 g/day, in clinical and endoscopic remission at week 8 were similar and significantly (P < 0.05) greater than placebo in subgroups stratified by disease extent, disease severity and gender and among patients not previously receiving low-dose 5-aminosalicylic acid. Among patients transferring directly from prior low-dose oral 5-aminosalicylic acid, MMX mesalazine 4.8 g/day was significantly (P = 0.018) more effective than placebo in inducing clinical and endoscopic remission. Efficacy over placebo did not reach significance in patients transferring directly to MMX mesalazine 2.4 g/day.

CONCLUSION

MMX mesalazine is effective in active UC regardless of disease extent, disease severity, gender and previous, low-dose, 5-ASA therapy.

Ulcerative proctitis: a review of pharmacotherapy and management

BACKGROUND

Ulcerative proctitis (UP) is a common presentation of ulcerative colitis (UC).

OBJECTIVE

To summarize available literature on up-to-date management and pharmacotherapy of UP patients.

METHODS

Extensive Medline/Embase literature search was performed to identify relevant articles.

RESULTS/CONCLUSION

Topical medication with rectally administered 5-aminosalicylic acid (5-ASA)/corticosteroid suppositories or enemas is effective treatment for most UP patients. Locally administered 5-ASA is more efficacious than oral compounds. The combination of topical 5-ASA and oral 5-ASA or topical steroids should be considered for escalation of treatment. Maintenance treatment is indicated in all UC cases. 5-ASA suppositories are suggested as first-line maintenance therapy if accepted by patients, although oral 5-ASA as maintenance therapy might prevent proximal extension of the disease. After re-assessment, chronically active patients refractory or intolerant to 5-ASAs and corticosteroids may require immunomodulators or biological therapy. Exceptional cases may require a proctocolectomy.

The risks and the benefits of mesalazine as a treatment for ulcerative colitis

Mesalazine is a 5-aminosalicylic acid compound that is the primary treatment for mild-to-moderate ulcerative colitis. In both oral and topical formulations it has demonstrated efficacy in both induction of active colitis and maintenance of remission, regardless of the extent of inflammation. In addition, there is indirect evidence of a role in the chemoprophylaxis of colorectal cancer in these patients. Mesalazine is generally well tolerated by patients, although serious adverse effects have been reported. In particular, worsening of colitis, interstitial pneumonitis and nephritis are of concern to clinicians. Fortunately these reactions are mostly reversible with cessation of therapy.

Drug insight: aminosalicylates for the treatment of IBD

Sulfasalazine and mesalazine (also known as mesalamine; 5-aminosalicylic acid) preparations have for many years been used for the treatment of IBD (i.e. ulcerative colitis and Crohn's disease), for both active disease and the control of remission. It has also been suggested that mesalazine is a chemoprophylactic agent that protects against the development of colorectal cancer. This Review focuses on the latest clinical evidence for the use of these aminosalicylates for the treatment of IBD, and concludes that sulfasalazine and mesalazine are useful for the treatment of both active and quiescent ulcerative colitis, whereas they have no clinical effect on either active or inactive Crohn's disease. Furthermore, evidence is lacking that mesalazine per se is a chemoprophylactic agent.

Review article: aminosalicylates for distal colitis

About two-thirds of patients with ulcerative colitis have an inflammatory involvement distal to the splenic flexure and therefore may be effectively treated with topical treatment. This allows the delivery of the active drug directly to the site of inflammation, limiting the systemic absorption and the potential side effects. Topical aminosalicylate therapy is the most effective approach, provided that the formulation reaches the upper extent of the disease. Suppositories should be considered the treatment of choice for proctitis and distal sigmoiditis. A 1 g Pentasa-suppository once daily induces a quicker clinical and endoscopic remission and was better tolerated than a 500-mg suppository twice daily. Enemas, foams and gel, thanks to their proximal spread, should be the treatment of choice for proctosigmoiditis and left-sided colitis. Oral aminosalicylates are less effective than topical therapies for patients with active disease; however, a combination of oral and topical aminosalicylates can be successfully tried in refractory patients. Topical aminosalicylates also play an important role in the maintenance of remission, and the combination of oral plus rectal 5-aminosalicylate is superior to the single agent. Patients who prefer not to continue on long-term rectal therapy can be treated with oral aminosalicylates.

Review article: mode of action and delivery of 5-aminosalicylic acid - new evidence

The effectiveness of sulfasalazine depends on the splitting of the diazo bond in the molecule by the action of bacteria in the large bowel, releasing the pharmacologically active moiety, 5-aminosalicylic acid. The development of pH-dependent, delayed-release formulations of 5-aminosalicylic acid abolished the toxicity associated with the sulfapyridine part of sulfasalazine. 5-aminosalicylic acid is now believed to act by activating a class of nuclear receptors involved in the control of inflammation, cell proliferation, apoptosis and metabolic function, the gamma form of peroxisome proliferator-activated receptors. These receptors are expressed at particularly high levels in colon epithelial cells, where their expression appears to be at least in part stimulated by gut bacteria. Other drugs known to act via peroxisome proliferator-activated receptor-gamma, such as rosiglitazone and the selective peroxisome proliferator-activated receptor-gamma ligand GW1929, can be displaced from their binding sites on the peroxisome proliferator-activated receptor-gamma molecule by 5-aminosalicylic acid at concentrations of 5-aminosalicylic acid that correspond with the concentrations found in the lumen of ulcerative colitis patients taking oral mesalazine. Genetically engineered heterozygous knockout mice (peroxisome proliferator-activated receptor-gamma+/-) are particularly susceptible to colonic inflammation, and inflammation is more severe in these mice, in response to chemicals that induce experimental colonic ulcers. In these experimental models, 5-aminosalicylic acid is ineffective in peroxisome proliferator-activated receptor-gamma+/- mice. This new insight provides a mechanistic foundation for the possibility that long-term treatment with 5-aminosalicylic acid can reduce the risk of colorectal cancer in patients with ulcerative colitis.

Review article: evolutionary advances in the delivery of aminosalicylates for the treatment of ulcerative colitis

Ulcerative colitis is a chronic and debilitating disease that involves inflammation of the colonic mucosa. Current therapies aim to reduce the symptom burden of ulcerative colitis and maintain disease quiescence. The standard first-line treatment for mild-to-moderate ulcerative colitis is 5-aminosalicylate therapy, which is available in oral and rectal (topical) formulations. While current 5-aminosalicylate formulations are effective in the majority of patients, they are associated with a number of limitations including inconvenient dosing regimens and poor patient acceptability, which may lead to non-compliance with prescribed therapy. A variety of improved delivery mechanisms have been developed in an effort to overcome these limitations. Micropellet formulations and high-dose tablets appear to offer comparable efficacy and tolerability to conventional formulations, although any benefit in terms of long-term patient compliance remains to be proven. Novel methods of delivery, such as those using a combination of hydrophilic and lipophilic matrices, designed to provide once-daily dosing in a high-strength tablet, may offer a significant improvement in the therapy of active and quiescent ulcerative colitis. This review examines the limitations of current 5-aminosalicylate formulations and reports on the evolution of novel oral formulations designed to overcome these limitations, maximize patient compliance during both induction and maintenance of quiescence, and optimize overall clinical outcomes.

Combined oral and topical mesalazine treatment for extensive ulcerative colitis

BACKGROUND

A 32-year-old white Jewish woman was referred to our clinic in October 2002 for a second opinion on the management of her active extensive ulcerative colitis that did not respond to oral mesalazine (mesalamine) 3.6 g/day. The severity of symptoms had affected her plans to have children.

INVESTIGATIONS

Laboratory investigations, including perinuclear antineutrophil cytoplasmic antibodies and antibodies to Saccharomyces cerevisiae, stool cultures, and sigmoidoscopy to 40 cm from the rectum, with biopsies.

DIAGNOSIS

Moderate-to-severe active extensive ulcerative colitis, unresponsive to mesalazine at 3.6 g/day.

MANAGEMENT

Oral mesalazine 4.8 g/day and 4 g mesalazine enemas nightly.

Systematic review: the use of mesalazine in inflammatory bowel disease

BACKGROUND

Mesalazine is among the medications most commonly prescribed by gastroenterologists, having to a large extent superseded sulfasalazine (sulphasalazine). However, there are still a number of aspects regarding its use which provoke debate and controversy.

AIM

To provide a systematic assessment of the evidence for the use of mesalazine in ulcerative colitis and Crohn's disease.

METHODS

References were identified using PubMed database. Additional references were identified with related article searches.

RESULTS

Mesalazine has a clear role in the maintenance of remission in ulcerative colitis and management of mild to moderately active disease, although the efficacy of topical preparations or combined topical and oral is clearly superior to oral alone. Evidence that increasing the dose of oral mesalazine improves efficacy is not clear-cut. The benefits of mesalazine in the management of acute Crohn's disease and the maintenance of remission are questionable and alternative treatments are usually more appropriate. Emerging evidence suggests that maintenance mesalazine reduces the risk of neoplastic progression in chronic ulcerative colitis. Compliance with therapy is thus important, as is an understanding of individuals most likely to default on this.

CONCLUSION

Evidence for a beneficial effect of mesalazine is largely confined to the management of ulcerative colitis.

Silencing of SH-PTP2 defines a crucial role in the inactivation of epidermal growth factor receptor by 5-aminosalicylic acid in colon cancer cells

Recent studies have suggested that 5-aminosalicylic acid (5-ASA) inhibits colorectal cancer (CRC) development. However, the mechanism underlying the antineoplastic effect of 5-ASA remains unknown. We here examined the effect of 5-ASA on epidermal growth factor receptor (EGFR) activation, a pathway that triggers mitogenic signals in CRC cells. We show that 5-ASA inhibits EGFR activation, through a mechanism that does not rely on CRC cell death induction. 5-ASA enhances the activity, but not expression, of phosphorylated (p)-EGFR-targeting phosphatases (PTPs), and treatment of cells with PTP inhibitors abrogates the 5-ASA-mediated EGFR dephosphorylation. Both SH-PTP1 and SH-PTP2 interact with EGFR upon 5-ASA treatment. However, knockdown of SH-PTP2 but not SH-PTP1 by small interference RNAs prevents the 5-ASA-induced EGFR dephosphorylation. Finally, we show that 5-ASA attenuates p-EGFR in ex vivo organ cultures of CRC explants. Data indicate that 5-ASA disrupts EGFR signalling by enhancing SH-PTP2 activity, and suggest a mechanism by which 5-ASA interferes with CRC growth.

Colonic targeting of aminosalicylates for the treatment of ulcerative colitis

Aminosalicylates (5-aminosalicylic acid) represent drugs of first choice in the treatment of ulcerative colitis. Two different therapeutic approaches have been employed to target the active 5-aminosalicylic acid to its site of action. Either inactive azo-prodrugs (e.g. sulfasalazine, olsalazine, balsalazide) or special galenic formulations have been developed for topical delivery of 5-aminosalicylic acid to the colon. However, as intestinal physiology, the extent of ulcerative colitis as well as drug disposition demonstrate large interindividual differences, acute healing rates (40-80%) and the maintenance of remission are quite variable. Apparently, therapeutic effects depend on local concentrations of 5-aminosalicylic acid in the colonic mucosa whereas systemic drug exposure might be one determinant of side effects. In general, 5-aminosalicylic acid is well tolerated and withdrawal from therapy is rare. Following administration of azo-prodrugs (e.g. olsalazine), lower plasma concentrations and higher delivery into the colon of 5-aminosalicylic acid can be observed in comparison to special galenic formulations of 5-aminosalicylic acid. Whether such changes in drug disposition will affect therapeutic efficacy remains to be proved by clinical data. Consequently, selection of a particular agent should be based primarily on clinical efficacy, profile of adverse effects, patients' acceptance and economic considerations.