Empagliflozin attenuates intestinal inflammation through suppression of nitric oxide synthesis and myeloperoxidase activity in in vitro and in vivo models of colitis

Inflammatory bowel diseases (IBD) are characterized by chronic and relapsing inflammation affecting the gastrointestinal (GI) tract. The incidence and prevalence of IBD are relatively high and still increasing. Additionally, current therapeutic strategies for IBD are not optimal. These facts urge todays' medicine to find a novel way to treat IBD. Here, we focused on the group of anti-diabetic drugs called gliflozins, which inhibit sodium glucose co-transporter type 2 (SGLT-2). Numerous studies demonstrated that gliflozins exhibit pleiotropic effect, including anti-inflammatory properties. In this study, we tested the effect of three gliflozins; empagliflozin (EMPA), dapagliflozin (DAPA), and canagliflozin (CANA) in in vitro and in vivo models of intestinal inflammation. Our in vitro experiments revealed that EMPA and DAPA suppress the production of nitric oxide in LPS-treated murine RAW264.7 macrophages. In in vivo part of our study, we showed that EMPA alleviates acute DSS-induced colitis in mice. Treatment with EMPA reduced macro- and microscopic colonic damage, as well as partially prevented from decrease in tight junction gene expression. Moreover, EMPA attenuated biochemical inflammatory parameters including reduced activity of myeloperoxidase. We showed that SGLT-2 inhibitors act as anti-inflammatory agents independently from their hypoglycemic effects. Our observations suggest that gliflozins alleviate inflammation through their potent effects on innate immune cells.

Regulators of G-Protein Signaling (RGS) in Sporadic and Colitis-Associated Colorectal Cancer

Colorectal cancer (CRC) is one of the most common neoplasms worldwide. Among the risk factors of CRC, inflammatory bowel disease (IBD) is one of the most important ones leading to the development of colitis-associated CRC (CAC). G-protein coupled receptors (GPCR) are transmembrane receptors that orchestrate a multitude of signaling cascades in response to external stimuli. Because of their functionality, they are promising targets in research on new strategies for CRC diagnostics and treatment. Recently, regulators of G-proteins (RGS) have been attracting attention in the field of oncology. Typically, they serve as negative regulators of GPCR responses to both physiological stimuli and medications. RGS activity can lead to both beneficial and harmful effects depending on the nature of the stimulus. However, the atypical RGS-AXIN uses its RGS domain to antagonize key signaling pathways in CRC development through the stabilization of the β-catenin destruction complex. Since AXIN does not limit the efficiency of medications, it seems to be an even more promising pharmacological target in CRC treatment. In this review, we discuss the current state of knowledge on RGS significance in sporadic CRC and CAC with particular emphasis on the regulation of GPCR involved in IBD-related inflammation comprising opioid, cannabinoid and serotonin receptors.

The Role of Chronic Fatigue in Patients with Crohn's Disease

Crohn's disease (CD) is a chronic, relapsing disorder belonging to inflammatory bowel diseases (IBD). It is manifested by relapsing transmural inflammation found in any segment of the gastrointestinal tract. Chronic fatigue is a common and underrecognized symptom of CD for which the prevalence is much higher in the population of CD patients compared to the healthy population. It stems from an intricate web of interactions between various risk factors, and its pathophysiology is still not fully understood. The implementation of routine screening and a holistic, multidisciplinary approach involving psychological support may be crucial in the management of CD patients with chronic fatigue. There is currently no single intervention aimed at decreasing fatigue alone, and its treatment is especially difficult in patients with fatigue persisting despite clinical and endoscopic remission. Extensive research is still needed in order to be able to predict, prevent, identify, and ultimately treat fatigue associated with CD. The aim of this review is to summarize the knowledge on the etiology, diagnosis, and treatment of chronic fatigue in CD patients.

Pharmacological approaches to treat intestinal pain

INTRODUCTION

Pain is one of the most substantial factors responsible for lowering quality of life in patients with intestinal diseases. Its multifactorial pathogenesis makes intestinal pain difficult to manage with currently available medications, especially considering the risk of serious adverse effects and exacerbation of underlying disease.

AREAS COVERED

The most commonly administered drugs in intestinal pain are medications forming the so-called analgesic ladder, which act directly on pain sensation: acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), and opioids in full range of activity strength. However, there are also many groups of supportive medications, which target intestinal pain indirectly and therefore, differs in applicability depending on underlying conditions and their pathophysiology, e.g. antispasmodics, antidepressants, probiotics, biological anti-inflammatory drugs. In this review, we concentrated on possible analgesic options in patients suffering from irritable bowel syndrome (IBS), inflammatory bowel diseases (IBD) and colorectal cancer (CRC). Moreover, we examined future perspectives in treating abdominal pain with medications targeting transient receptor potential channels, the endocannabinoid system and other promising options, including new formulations of already known drugs and new peripherally-restricted opioids.

EXPERT OPINION

There is constant need for improvement of intestinal analgesia and novel pharmacological approaches, from which interaction with TRP receptors is a particularly promising direction.

On the Way to Improve Diagnostic Marker Panel for Acute Appendicitis in Adults: the Role of Calprotectin

Calprotectin is a positive acute-phase protein participating in innate immune responses and inflammatory processes. This protein is produced mainly in neutrophils, which infiltrate inflamed tissues and then increase the level of calprotectin in plasma, urine, or body secretions. Its measurement is used in the diagnosis of many inflammatory diseases of the gastrointestinal tract. Here, we reviewed the studies evaluating the utility of calprotectin when the patient is suspected of acute appendicitis, one of the most common causes of abdominal pain. Fecal and serum calprotectin provide clinicians additional information as compared to routinely performed laboratory analyses. Moreover, among all forms of the protein, the fecal calprotectin seems to be a particularly promising biomarker due to its high resistance to degradation in the stool. In the future, innovative methods in the form of neural networks may play a valuable role in developing such panels. These findings are important because current literature showed that sensitive and specific markers of acute appendicitis are still urgently needed.

Characterization of the Synergistic Effect between Ligands of Opioid and Free Fatty Acid Receptors in the Mouse Model of Colitis

Background: Recent studies suggest that lipids, including free fatty acids (FFAs), are necessary for proper μ opioid receptor (MOR) binding and that activation of opioid receptors (ORs) improves intestinal inflammation. The objective of the study was to investigate a possible interaction between the ORs and FFA receptors (FFARs) ligands in the colitis. Methods: The potential synergistic effect of ORs and FFARs ligands was evaluated using mouse model of acute colitis induced by dextran sulfate sodium (DSS, 4%). Compounds were injected intraperitoneally (i.p.) once or twice daily at the doses of 0.01 or 0.02 mg/kg body weight (BW) (DAMGO—an MOR agonist), 0.3 mg/kg BW (DPDPE—a δ OR (DOR) agonist) and 1 mg/kg BW (naloxone—a non-selective OR antagonist, GLPG 0974—a FFAR2 antagonist, GSK 137647—a FFAR4 agonist and AH 7614—a FFAR4 antagonist) for 4 days. Results: Myeloperoxidase (MPO) activity was significantly decreased after DAMGO (0.02 mg/kg BW) and GSK 137647 (1 mg/kg BW) administration and co-administration as compared to DSS group. Conclusions: Treatment with ligands of ORs and FFARs may affect the immune cells in the inflammation; however, no significant influence on the severity of colitis and no synergistic effect were observed.

Management of pain in colorectal cancer patients

In this review we focus on the pathophysiology of CRC-related pain and discuss currently applied pain management. Pain is a symptom reported by over 70 % of colorectal cancer (CRC) patients. It remains a feared and debilitating consequence of both cancer and cancer-related treatment. There are many options for pain management in CRC, consisting of intravenous, oral or topical medications. In order to address the full spectrum of pain, proper treatment should address the nociceptive, neuropathic and/or psychogenic pain component. Currently available methods do not bring pain relief to satisfying number of patients and, if used improperly, can cause a number of complications. Therefore, future treatments should focus primarily on alleviating pain, but also on reducing possible side effects. In this article we cover recent and promising pharmacological and non- pharmacological developments emerging in the field of CRC treatment.

Dietary Carbohydrates and Lipids in the Pathogenesis of Leaky Gut Syndrome: An Overview

This review summarizes the recent knowledge on the effects of dietary carbohydrates and lipids on the pathophysiology of leaky gut syndrome (LGS). Alterations in intestinal barrier permeability may lead to serious gastrointestinal (GI) disorders. LGS is caused by intestinal hyperpermeability due to changes in the expression levels and functioning of tight junctions. The influence of dietary habits on intestinal physiology is clearly visible in incidence rates of intestinal diseases in industrial and developing countries. Diseases which are linked to intestinal hyperpermeability tend to localize to Westernized countries, where a diet rich in fats and refined carbohydrates predominates. Several studies suggest that fructose is one of the key carbohydrates involved in the regulation of the intestinal permeability and its overuse may cause harmful effects, such as tight junction protein dysfunction. On the other hand, short chain fatty acids (mainly butyrate) at appropriate concentrations may lead to the reduction of intestinal permeability, which is beneficial in LGS. However, long chain fatty acids, including n-3 and n-6 polyunsaturated fatty acids have unclear properties. Some of those behave as components untightening and tightening the intestinal membrane.

Single Nucleotide Polymorphisms in Colitis-Associated Colorectal Cancer: A Current Overview with Emphasis on the Role of the Associated Genes Products

Colitis-Associated Colorectal Cancer (CA-CRC) is one of the most severe complications of Inflammatory Bowel Disease (IBD) and constitutes the cause of death in 10-15% of patients. The risk ratio for carcinogenesis depends on numerous factors, such as the extent of intestinal inflammatory lesions and the duration of the disease. CA-CRC is a major problem of today's gastroenterology and colorectal surgery due to the fact that the incidence and prevalence of IBD are increasing. In this review, we discussed the current state of knowledge regarding genetic differences between sporadic CRC and CA-CRC, especially pertaining to the chromosomal instability mechanism (CIN). In order to explain CA-CRC molecular basis, we have analyzed the data from studies regarding the correlations between CA-CRC and the presence of Single Nucleotide Polymorphisms (SNPs). Further focus on the role of associated proteins has emphasized the role of NF-κB signaling as the main link between inflammation and carcinogenesis during the course of IBD.