Andrzej Wasilewski

Beneficial Effects of Probiotics, Prebiotics, Synbiotics, and Psychobiotics in Inflammatory Bowel Disease.

Abstract:Inflammatory bowel disease (IBD) is a group of diseases characterized by inflammation of the small and large intestine and primarily includes ulcerative colitis and Crohns disease. Although the etiology of IBD is not fully understood, it is believed to result from the interaction of genetic, immunological, and environmental factors, including gut microbiota. Recent studies have shown a correlation between changes in the composition of the intestinal microbiota and IBD. Moreover, it has been suggested that probiotics and prebiotics influence the balance of beneficial and detrimental bacterial species, and thereby determine homeostasis versus inflammatory conditions. In this review, we focus on recent advances in the understanding of the role of prebiotics, probiotics, and synbiotics in functions of the gastrointestinal tract and the induction and maintenance of IBD remission. We also discuss the role of psychobiotics, which constitute a novel class of psychotropic agents that affect the central nervous system by influencing gut microbiota.

Role of transient receptor potential channels in intestinal inflammation and visceral pain: novel targets in inflammatory bowel diseases.

Abstract:Transient receptor potential (TRP) channels are a large group of ion channels that are prevalent in mammalian tissues. They are widely distributed in the central and peripheral nervous systems, and in nonneuronal cells, where they are implicated in sensing temperature, noxious substances, and pain. TRPs play an important role in immune response and nociception and, therefore, may be involved in the pathogenesis of inflammatory bowel diseases, whose major symptoms include chronic inflammatory state and abdominal pain. In this review, we summarize what is known on TRP channels in inflammatory bowel disease and visceral pain; we focus in particular on TRPV1, TRPV4, TRPA1, and TRPM. We also analyze scientific reports that evidence potential use of TRP regulators in future inflammatory bowel disease treatment.

Cannabinoid Receptor Type 1 and mu-Opioid Receptor Polymorphisms Are Associated With Cyclic Vomiting Syndrome

Objectives:Cyclic vomiting syndrome (CVS) is a disorder defined by recurrent, unexplained episodes of severe nausea and vomiting. Our aim was to investigate whether CVS and pathophysiological mechanisms underlying this condition are associated with selected variations in genes encoding the components of the endogenous cannabinoid and opioid systems.Methods:This case–control study included 65 patients with CVS-16 male and 49 female, and 1,092 healthy controls-525 male and 567 female from the 1000 Genomes Project. CVS subjects filled out study-specific questionnaires. Single-nucleotide polymorphisms (SNPs) in genes encoding cannabinoid receptors (CNR1 and CNR2), fatty acid amide hydrolase (FAAH) and mu-opioid receptor (OPRM1) were analyzed using the TaqMan SNP genotyping assay. Correlations between SNP’s and clinical characteristics of CVS were ascertained.Results:Our study disclosed an increased risk of CVS among individuals with AG and GG genotypes of CNR1 rs806380 (P<0.01), whereas the CC genotype of CNR1 rs806368 and AG and GG genotypes of OPRM1 rs1799971 were associated with a decreased risk of CVS (P<0.05). In addition, AG and GG genotypes of OPRM1 rs1799971 were correlated with migraine episodes, AG and GG of OPRM1 rs1799971, and CT and CC of CNR1 rs806368 with a family history of migraines (second degree relatives), and CT and CC of CNR1 rs2023239 with a positive response to therapy.Conclusions:Our results show for the first time that the variations in CNR1 and OPRM1 genes are associated with CVS and that different genotypes may contribute to the risk of CVS.

Tenapanor hydrochloride for the treatment of constipation-predominant irritable bowel syndrome

Introduction: Constipation-predominant irritable bowel syndrome (IBS-C) is a common functional gastrointestinal (GI) disorder characterized by recurrent abdominal pain and prolonged GI transit. The pathogenesis of IBS-C has still not been established; therefore, drugs currently in use in IBS-C act mainly symptomatically, whereas novel pharmacological targets are urgently needed. Tenapanor is a potent inhibitor of Na+/H+ exchanger 3 [NHE3], localized in the apical membrane of intestinal epithelial cells. NHE3 participates in the uptake of sodium ions and water from the intestinal lumen. Areas covered: In this review, the authors discuss pharmacodynamics and pharmacokinetics of tenapanor, focusing on animal models and in vitro studies. They also summarize clinical trials on tenapanor’s safety and efficacy in view of its potential role in IBS-C therapy. Expert opinion: Tenapanor possesses an excellent preclinical safety profile and, as of now, there are no serious concerns about its side effects. The non-systemic action of tenapanor constitutes a significant advantage, as it minimizes possible adverse effects or drug–drug interactions. However, Phase III clinical trials are still needed to confirm results obtained in earlier phases and optimize the dose–response for tenapanor, whereas limiting diarrhea, its major adverse effect.

Methyl-orvinol—Dual activity opioid receptor ligand inhibits gastrointestinal transit and alleviates abdominal pain in the mouse models mimicking diarrhea-predominant irritable bowel syndrome

BACKGROUND Diarrhea-predominant irritable bowel syndrome (IBS-D) is a functional disorder of the gastrointestinal (GI) tract. The major IBS-D symptoms include diarrhea, abdominal pain and discomfort. High density of opioid receptors (ORs) in the GI tract and their participation in the maintenance of GI homeostasis make ORs ligands an attractive option for developing new anti-IBS-D treatments. The aim of this study was to characterize the effect of methyl-orvinol on the GI motility and secretion and in mouse models mimicking symptoms of IBS-D. METHODS In vitro, the effects of methyl-orvinol on electrical field stimulated smooth muscle contractility and epithelial ion transport were characterized in the mouse colon. In vivo, the following tests were used to determine methyl-orvinol effect on mouse GI motility: colonic bead expulsion, whole GI transit and fecal pellet output. An antinociceptive action of methyl-orvinol was assessed in the mouse model of visceral pain induced by mustard oil. RESULTS Methyl-orvinol (10-10 to 10-6M) inhibited colonic smooth muscle contractions in a concentration-dependent manner. This effect was reversed by naloxone (non-selective opioid antagonist) and β-funaltrexamine (selective MOP antagonist). Experiments with a selective KOP receptor agonist, U50488 revealed that methyl-orvinol is a KOP receptor antagonist in the GI tract. Methyl-orvinol enhanced epithelial ion transport. In vivo, methyl-orvinol inhibited colonic bead expulsion and prolonged GI transit. Methyl-orvinol improved hypermotility and reduced abdominal pain in the mouse models mimicking IBS-D symptoms. CONCLUSION Methyl-orvinol could become a promising drug candidate in chronic therapy of functional GI diseases such as IBS-D.

Role of G protein-coupled orphan receptors in intestinal inflammation: novel targets in inflammatory bowel diseases.

Abstract:A large number of proteins were classified into the family of G protein-coupled receptors (GPCRs). Based on their characteristic serpentine domain, they are called 7 TM receptors. Presently, their ligands and physiological functions remain unknown. In this review, we summarize what is known on these receptors and discuss the potential use of these orphan GPCRs (GPRs) in the induction or maintenance of remission in inflammatory bowel diseases. We focus on GPRs 30, 41, 43, 55, 119, and 120, where scientific evidence supports a potential role in intestinal inflammation.

Fatty acid amide hydrolase (FAAH) inhibitor PF-3845 reduces viability, migration and invasiveness of human colon adenocarcinoma Colo-205 cell line: an in vitro study

Earlier reports suggest that the endocannabinoids may play a role of endogenous tumor growth modulators. In this study, we investigated whether inhibition of the enzymes involved in the synthesis and degradation of endocannabinoids may reduce colorectal cancer cell invasion and migration. The human colon adenocarcinoma Colo-205 cells were incubated with PF-3845, JZL-184 and RHC-80267 (fatty acid amide hydrolase (FAAH), mono- (MAGL) and diacylglycerol lipase (DAGL) inhibitors, respectively) for 48 h. The MTT colorimetric assay was performed to quantify cell viability. Next, Colo-205 cells were incubated with PF-3845 alone or with PF-3845 together with selected antagonists: AM 251, AM 630, SB 366791, RN 1734 and G-15 (CB1, CB2, TRPV1, TRPV4 and GPR30 antagonists, respectively). Western blot assay was applied to identify the changes in CB1 and CB2 receptor expression. Migration and invasion assays were employed to characterize the effect of PF-3845 on colorectal cancer cell invasion. We found that of all the inhibitors used, the FAAH inhibitor PF-3845 reduced the Colo-205 cell line viability the most effectively (IC50=52.55 μM). We also showed that the effect of decreased cell viability was enhanced when Colo-205 cells were incubated with PF-3845 and RN-1734, a TRPV4 antagonist (IC50=30.54 μM). Western blot assay revealed significantly decreased CB1 receptor expression levels, while CB2 expression was increased in response to PF-3845 when compared to control. Furthermore, PF-3845 inhibited migration and invasion of Colo-205 cell line. These results suggest that pharmacological inhibition of FAAH and consequent enhancement of the endocannabinoid levels may reduce the colorectal cancer growth and progression.

The effect of opioid agonists and antagonists on gastrointestinal motility in mice selected for high and low swim stress-induced analgesia.

The opioid system in the gastrointestinal (GI) tract plays an important physiological role, but is also responsible for the side effect of opioid drugs, including troublesome constipation in chronic pain treatment. The aim of this study was to characterize and validate a new mouse model to study the effects of opioid agonists and antagonists in the GI tract.

FABP4 blocker attenuates colonic hypomotility and modulates white adipose tissue-derived hormone levels in mouse models mimicking constipation-predominant IBS

The role of fatty acid binding protein 4 (FABP4) in lower gastrointestinal (GI) motility is unknown. We aimed to verify the effect of inhibition of FABP4 on GI transit in vivo, and to determine the expression of FABP4 in mouse and human tissues.

High activity of endogenous opioid system protects against gastric damage development in mouse models of gastric mucosal injury

BACKGROUND Gastric mucosal injury appears when acid and pepsin production, simultaneously with inadequate mucosal response, overwhelms protective mechanism in stomach. Here we aimed to explore the linkage between gastric lesion formation and endogenous opioid system activity. METHODS Two mouse lines bidirectionally selected for high (HA) and low (LA) swim stress-induced analgesia associated with high and low endogenous opioid system activity were used. Gastric mucosal injury was induced by ethanol (EtOH) and chronic mild stress. To investigate the anti-inflammatory effect of the endogenous opioid system macroscopic score, myeloperoxidase (MPO) activity, the expression of inflammatory molecules as well as oxidative stress markers were determined. Moreover, expression of opioid receptors μ (MOR), κ (KOR) and δ (DOR) at mRNA levels were determined in gastric tissue. RESULTS High activity of the endogenous opioid system alleviated gastric lesions development in the EtOH-and chronic mild stress-induced mouse gastric mucosal injury models, as demonstrated by decreased macroscopic score in HA line compared to LA. Additionally, antioxidative stress defence mechanisms were positively modulated in both models of gastric mucosal injury. MOR and partially KOR receptors may be responsible for the gastroprotective effect. CONCLUSION To our knowledge this is the first study to show that increased activity of the endogenous opioid system prevents from gastric lesion formation by influencing - among others - the anti-inflammatory and anti-oxidant mechanisms in the mice stomach. Hence, we suggest that opioids may play an important role in gastric mucosal injury prevention.