STW 5 is effective in dextran sulfate sodium-induced colitis in rats

Effect of Iberogast (STW5) on tolerance to colonic gas in patients with irritable bowel syndrome: A randomized, double-blind, placebo control clinical trial

BACKGROUND

STW5 is an herbal medicinal product that, in previous studies, reduced abdominal pain in irritable bowel syndrome (IBS). The effect of STW5 on gas-related abdominal symptoms is unknown.

AIM

To determine the effects of STW5, compared to placebo, on the responses to colonic gas in IBS.

METHODS

Using a cross-over design, two gas challenge tests were performed in 10 patients with IBS and bloating after 2-weeks treatment with (a) STW5 and (b) placebo. The challenge test consisted in continuous infusion of gas into the colon (24 mL/min for 60 min), followed by a 30-min free evacuation period. Gas evacuation, symptom perception, and abdominal distension were continuously registered.

RESULTS

Colonic gas filling was associated to a significant rise in abdominal symptom perception, that was significantly greater when patients were on-placebo (score increment 4.0 ± 0.3) compared with on-STW5 (score increment 3.2 ± 0.4; p = 0.035). Gas filling was associated to a progressive abdominal distension that was similar with both treatments. Opening of the rectal cannula produced a massive gas evacuation, similar after both treatments, associated to a return of abdominal perception and distension to basal levels when patients were on-STW5 (score increment -0.1 ± 0.4; distension 0.3 ± 0.2 cm; p = 0.399, and p = 0.112 vs. basal), whereas both remained increased on-placebo (score increment 0.5 ± 0.3; distension 0.8 ± 0.3 cm; p = 0.048, and p = 0.016 vs. infusion start).

CONCLUSIONS

STW5 improves colonic gas tolerance in IBS patients with bloating without a significant effect on gas retention and evacuation. This medicinal product can be beneficious for treatment of gas-related abdominal symptoms in patients with bloating. EudraCT: 2019-003976-38.

Rice bran extract mitigates depressive-like behavior in dextran sulfate sodium-induced colitis: Involvement of the gut-brain axis and Sirt1 signaling pathway

Inflammatory bowel disease (IBD) patients frequently suffer from depressive disorders as well. The present study was carried out to explore whether treatment with a standardized rice bran extract (RBE) could affect depression-like behavior in rats with dextran sulfate sodium (DSS)-induced colitis. Male Wistar rats were treated with RBE (100 mg/kg/day; p.o.) for 2 weeks. During the second week, colitis was induced by feeding the rats with 5 % (w/v) DSS in drinking water. RBE protected against DSS-induced body weight loss as well as against the macro- and microscopic inflammatory changes of the colon. Additionally, RBE mitigated DSS-induced dysregulation in blood-brain barrier tight junctional proteins, preserved the hippocampal histopathological architecture and improved the animal behavior in the forced swimming test. This was associated with modulation of hippocampal oxidative stress marker; GSH as well as hippocampal pro-inflammatory mediators; NF-ĸB and IL-1β. Treatment with RBE also led to a profound increase in the hippocampal levels of Sirt1, PGC-1α, Nrf2, and HO-1, which were drastically dropped by DSS. In conclusion, the study revealed the protective effect of RBE against DSS-induced depressive-like behavior through modulation of different parameters along the gut-brain axis and up-regulated the Sirt1/PGC-1α/Nrf2/HO-1 signaling pathway.

Niacin modulates depressive-like behavior in experimental colitis through GPR109A-dependent mechanisms

AIMS

Depression is one of the common neurological comorbidities in patients with inflammatory bowel disease (IBD). The current study aimed to investigate the potential impact of niacin on colitis-induced depressive-like behavior in rats.

MATERIALS AND METHODS

Animals were given 5 % dextran sulfate sodium (DSS) in drinking water for one week to induce colitis. Niacin (80 mg/kg), with or without mepenzolate bromide (GPR109A blocker), was administered once per day throughout the experimental period. Rats were tested for behavioral changes using open field and forced swimming tests.

KEY FINDINGS

Niacin significantly ameliorated DSS-induced behavioral deficits and alleviated macroscopic and microscopic colonic inflammatory changes. It also augmented the hippocampal levels of ZO-1, occludin, and claudin-5 proteins, indicating the ability of niacin to restore the blood-brain barrier (BBB) integrity. Moreover, niacin decreased hippocampal IL-1ꞵ and NF-ĸB contents but increased GSH, Sirt-1, Nrf-2, HO-1 concentrations. All these beneficial effects were partially abolished by the co-administration of mepenzolate bromide.

SIGNIFICANCE

The neuroprotective effect of niacin against DSS-induced depressive-like behavior was partially mediated through GPR109A-mediated mechanisms. Such mechanisms are also involved in modulating neuronal oxidative stress and inflammation via Sirt-1/Nrf-2/HO-1 signaling pathways.

The synbiotic mixture of Bacillus licheniformis and Saccharomyces cerevisiae extract aggravates dextran sulfate sodium induced colitis in rats

BACKGROUND

Uncertain effects of probiotics and/or prebiotics have been reported in experimental and clinical colitis. This study aims to examine the effects of a synbiotic combination comprising Bacillus licheniformis DSM 17236 and Saccharomyces cerevisiae cell wall extract on dextran sulfate sodium (DSS)-induced colitis in Sprague Dawley rats.

METHODS

Acute colitis was induced in rats by oral administration of DSS 3.5% for 7 days. Fifty rats were divided equally into five groups; one control group and the other groups were induced with colitis and treated with or without the tested synbiotic, mixed with diet, for 28 days and sulfasalazine (100 mg/kg) via intragastric tube once daily for 14 days.

RESULTS

Symptomatically, the synbiotic administration raised the disease activity index (DAI) to comparable scores of the DSS group, specially from the 2nd to 7th days post DSS intoxication. It also induced a significant (p < 0.05) amplification of WBCs, myeloperoxidase (MPO), malondialdehyde (MDA), nuclear factor kappa B (NF-kB) expression and proinflammatory cytokines tumor necrosis factor alpha (TNFα), interferon gamma (INFγ), and interleukin-1 beta (IL-1β) while depressed the antioxidant enzymes glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) when compared with the DSS and control groups. The DSS intoxicated and Synbiotic+DSS groups showed desquamations of the covering epithelium, noticeable diffuse leukocytic infiltrations, sever catarrhal enteritis, ischemic colitis with diffuse coagulative necrosis of the entire colonic mucosa. Contrarily, sulfasalazine proved to be effective in the reduction of the tested inflammatory markers and the pathological degenerative changes of the DSS ulcerative colitis.

CONCLUSION

The examined synbiotic did not ameliorate but aggravated the DSS-induced colitis, so it should be subjected to intensive experimental and clinical testing before their use in animals and human.

Central administration of human opiorphin alleviates dextran sodium sulfate-induced colitis in mice through activation of the endogenous opioid system

The opioid system plays a crucial role in maintaining gastrointestinal homeostasis. Endogenous opioid peptide enkephalins have anti-inflammatory effect and participate in the treatment of inflammatory bowel diseases (IBDs). Here, we investigated the effect of natural enkephalinase inhibitor human opiorphin (HO) on dextran sodium sulfate (DSS)-induced colitis in mice. Our results showed that central administration of HO attenuated DSS-induced colitis, as indicated by the reduction of disease activity index (DAI) scores, macroscopic scores, histological scores, and the myeloperoxidase (MPO) activity. Moreover, HO alleviated DSS-induced inflammation by decreasing inflammatory cytokines TNF-α, IL-6, and IL-1β, and increasing anti-inflammatory cytokine IL-10 in both serum and colon tissues in DSS-treated mice. The potential anti-inflammatory effect of HO at a dose of 40 μg/kg was observed as evidenced by a decrease in nuclear factor κB (NF-κB) p65, toll-like receptor-4 (TLR-4), iNOS, and COX-2. HO also improved intestinal barrier function by enhancing the expression of tight junction proteins. Furthermore, HO treatment significantly inhibited activities of neutral endopeptidase (NEP) and aminopeptidase N (APN), elevated serum enkephalins concentrations, and increased expressions of mu and delta opioid receptors. In addition, pretreatment with opioid receptor antagonist naloxone hydrochloride (NH) compromised the protective effect of HO and aggravated colitis symptoms, as indicated by inhibited anti-inflammatory effects, disrupted intestinal barrier function, and decreased opioid receptor activity. In conclusion, these data indicate that HO protects against DSS-induced colitis by inhibiting TLR4/NF-κB pathway activation and improving intestinal barrier function through activation of the endogenous opioid system. Therefore, targeting the opioid system with peptidase inhibitors intervention would be a novel strategy in the therapy of IBD.

The herbal preparation STW 5 affects serotonergic pathways in the brain and colon as well as stress parameters in experimental irritable bowel syndrome

BACKGROUND

Exposure to stress has been related to disturbance in 5-hydroxytryptamine (5-HT) signaling in the brain-gut axis and is considered as a major predisposing factor for the development of irritable bowel syndrome (IBS). The present study aimed to investigate the possible involvement of 5-HT and some other stress-related parameters in the effectiveness of STW 5 against stress-induced IBS.

METHODS

Rats were subjected to restraint stress (RS) for 1 h/day for 14 consecutive days to induce IBS-like symptoms and were given STW 5 orally at the same time. At the end of the experiment, blood samples were withdrawn, then animals were euthanized and the brain hippocampi, cerebral cortices, as well as colons were isolated for biochemical and histopathological assessments.

RESULTS

RS increased the plasma corticotrophin releasing factor (CRF) with concomitant increase in hippocampal and cortical 5-HT levels, as well as mast cell inflammatory mediators, oxidative stress biomarkers, and histopathological inflammatory changes observed in rat colon. It also decreased the colonic content of 5-HT with consequent decrease in fecal pellet output (FPO). Treatment with STW 5 protected against these changes.

CONCLUSION

The protective effect of STW 5 against RS-induced IBS is related to its ability to normalize the induced changes in 5-HT in the brain-gut axis and counteract the stress-induced oxidative stress and inflammation.

Immunomodulatory peptides-A promising source for novel functional food production and drug discovery

Immunomodulatory peptides are a complex class of bioactive peptides that encompasses substances with different mechanisms of action. Immunomodulatory peptides could also be used in vaccines as adjuvants which would be extremely desirable, especially in response to pandemics. Thus, immunomodulatory peptides in food of plant origin could be regarded both as valuable suplements of novel functional food preparation and/or as precursors or possible active ingredients for drugs design for treatment variety of conditions arising from impaired function of immune system. Given variety of mechanisms, different tests are required to assess effects of immunomodulatory peptides. Some of those effects show good correlation with in vivo results but others, less so. Certain plant peptides, such as defensins, show both immunomodulatory and antimicrobial effect, which makes them interesting candidates for preparation of functional food and feed, as well as templates for design of synthetic peptides.

Effect of the standard herbal preparation, STW5, treatment on dysbiosis induced by dextran sodium sulfate in experimental colitis

BACKGROUND

The standardized herbal preparation, STW 5, is effective clinically in functional gastrointestinal disorders and experimentally in ulcerative colitis (UC). The present study explores whether the beneficial effect of STW 5 involves influencing the intestinal microbiota.

METHODS

UC was induced in Wistar rats by feeding them 5% dextran sodium sulfate (DSS) in drinking water for 7 days. Rats were treated concurrently with STW 5 and sacrificed 24 h after last drug administration. Fecal samples were used to determine changes in the abundance of selected microbial phyla and genera using real-time PCR.

RESULTS

Induction of UC led to dysbiosis and changes in the gut microbiota. The changes included an increase in some genera of the Firmicutes, namely Enterococcus, and a decrease in others, namely Blautia, Clostridium, and Lactobacillus. DSS further induced a marked increase in the abundance of Bacteroidetes and Proteobacteria as well as in the relative abundance of Actinobacteria and its genus Bifidobacterium. Methanobrevibacter levels (phylum Euryarchaeota) were also increased. Microbial dysbiosis was associated with changes in various parameters of colonic inflammation. STW 5 effectively guarded against those changes and significantly affected the indices of edema and inflammation in the UC model. Changes in colon length, colon mass index, inflammatory and apoptotic markers, and histological changes induced by DSS were also prevented.

CONCLUSIONS

Dysbiosis plays a contributing role in the development of DSS-induced UC. Derangements in the microbial flora and associated inflammatory processes were largely prevented by STW 5, suggesting that this effect might contribute towards its beneficial usefulness in this condition.

Effect of lecithin on oxidative stress in an experimental model of rats colitis induced by acetic acid

Ulcerative colitis (UC) is an inflammatory disease that affects the bowels. Reactive oxygen species (ROS) are involved in the progress of UC.

Objective Evaluate the antioxidant effect of lecithin in an experimental model of acute UC induced by administration of acetic acid (AA) in rats.

Methods Lecithin (0.5 mL/kg/day) administered orally 2 days before and after induction of colitis with 4% AA in a volume of 4 mL. Twenty-five male Wistar rats were divided in 5 groups: control (CO); control + lecithin (CO + LE); colitis (CL); colitis + lecithin (CL + LE); lecithin + colitis (LE + CL). Anal sphincter pressure, LPO (TBARS), and antioxidant activity of enzymes superoxide dismutase (SOD) and catalase (CAT) were measured, and a histological analysis with H&E was performed.

Results and discussion Anal sphincter pressure was significantly smaller in the CO group, lecithin treatment increased it in pre- and post-treated groups. LPO and SOD activity were increased in the CO group and decreased in the lecithin-treated groups. CAT activity was increased in CO group and decreased in lecithin groups. The histological analysis showed damage to the bowels with destruction of crypts, edema, and inflammatory infiltrate. Use of lecithin preserved the crypts and decreased the edema.

Conclusion Ulcerative colitis increased lipid peroxidation, and the use of lecithin was effective reducing damage to the bowels in the model of experimental colitis.

Radioprotective Agents and Enhancers Factors. Preventive and Therapeutic Strategies for Oxidative Induced Radiotherapy Damages in Hematological Malignancies

Radiation therapy plays a critical role in the management of a wide range of hematologic malignancies. It is well known that the post-irradiation damages both in the bone marrow and in other organs are the main causes of post-irradiation morbidity and mortality. Tumor control without producing extensive damage to the surrounding normal cells, through the use of radioprotectors, is of special clinical relevance in radiotherapy. An increasing amount of data is helping to clarify the role of oxidative stress in toxicity and therapy response. Radioprotective agents are substances that moderate the oxidative effects of radiation on healthy normal tissues while preserving the sensitivity to radiation damage in tumor cells. As well as the substances capable of carrying out a protective action against the oxidative damage caused by radiotherapy, other substances have been identified as possible enhancers of the radiotherapy and cytotoxic activity via an oxidative effect. The purpose of this review was to examine the data in the literature on the possible use of old and new substances to increase the efficacy of radiation treatment in hematological diseases and to reduce the harmful effects of the treatment.

Use of Evidence-Based Herbal Medicines for Patients with Functional Gastrointestinal Disorders: A Conceptional Framework for Risk-Benefit Assessment and Regulatory Approaches

BACKGROUND

Herbal or complementary medicines are frequently used for the treatment of patients with functional gastrointestinal disorders (FGID). Regulatory requirements for herbal therapies are inconsistent and, in many jurisdictions, herbal therapies are either self-, minimally- or unregulated.

AIM

To provide guidance for the appropriate and safe use of herbal medicines in patients with FGID patients with special consideration of the regulatory frameworks.

METHODS

A PubMed search of the literature was performed; relevant articles were included.

RESULTS

Similar to chemically defined therapies herbal medicines can cause adverse events. Thus, a risk-benefit appraisal should be undertaken for these therapies. While there is no disease specific mortality in FGID patients, patients with FGID who fail to respond to "empiric" chemically defined therapies undergo diagnostic and therapeutic measures that can be associated with appreciable morbidity and mortality. Thus, effective herbal treatments that subsequently reduce health-care utilization, reduce risks related to diagnostic or therapeutic measures that are initiated if no improvement of symptoms occurs. This "protective" effect of effective treatments for FGID needs to be taken in consideration when the risks and benefits of treatments are determined. In addition, standards that mirror regulations for chemically defined treatments should apply and the components of the respective preparations should undergo ongoing toxicological testing and rigorous quality assurance measures (including pharmacovigilance) applied.

CONCLUSIONS

Some herbal therapies offer significant benefits for patients with FGID. To ensure the safety of these treatments, the regulatory requirements should mirror requirements for chemically defined treatments.

Herbal Therapies in Functional Gastrointestinal Disorders: A Narrative Review and Clinical Implication

The pathophysiology of functional gastrointestinal disorders (FGIDs) is still unclear and various complex mechanisms have been suggested to be involved. In many cases, improvement of symptoms and quality of life (QoL) in patients with FGIDs is difficult to achieve with the single-targeted treatments alone and clinical application of these treatments can be challenging owing to the side effects. Herbal preparations as complementary and alternative medicine can control multiple treatment targets of FGIDs simultaneously and relatively safely. To date, many herbal ingredients and combination preparations have been proposed across different countries and together with a variety of traditional medicine. Among the herbal therapies that are comparatively considered to have an evidence base are iberogast (STW-5) and peppermint oil, which have been mainly studied and used in Europe, and rikkunshito and motilitone (DA-9701), which are extracted from natural substances in traditional medicine, are the focus of this review. These herbal medications have multi-target pharmacology similar to the etiology of FGIDs, such as altered intestinal sensory and motor function, inflammation, neurohormonal abnormality, and have displayed comparable efficacy and safety in controlled trials. To achieve the treatment goal of refractory FGIDs, extensive and high quality studies on the pharmacological mechanisms and clinical effects of these herbal medications as well as efforts to develop new promising herbal compounds are required.

STW 5 is effective against nonsteroidal anti-inflammatory drugs induced gastro-duodenal lesions in rats

BACKGROUND

Proton pump inhibitors are often used to prevent gastro-intestinal lesions induced by nonsteroidal anti-inflammatory drugs. However, they are not always effective against both gastric and duodenal lesions and their use is not devoid of side effects.

AIM

To explore the mechanisms mediating the clinical efficacy of STW 5 in gastro-duodenal lesions induced by nonsteroidal anti-inflammatory drugs (NSAIDs), exemplified here by diclofenac, in a comparison to omeprazole.

METHODS

Gastro-duodenal lesions were induced in rats by oral administration of diclofenac (5 mg/kg) for 6 successive days. One group was given concurrently STW 5 (5 mL/kg) while another was given omeprazole (20 mg/kg). A day later, animals were sacrificed, stomach and duodenum excised and divided into 2 segments: One for histological examination and one for measuring inflammatory mediators (tumor necrosis factor α, interleukins-1β and 10), oxidative stress enzyme (heme oxygenase-1) and apoptosis regulator (B-cell lymphoma 2).

RESULTS

Diclofenac caused overt histological damage in both tissues, associated with parallel changes in all parameters measured. STW 5 and omeprazole effectively prevented these changes, but STW 5 superseded omeprazole in protecting against histological damage, particularly in the duodenum.

CONCLUSION

The findings support the therapeutic usefulness of STW 5 and its superiority over omeprazole as adjuvant therapy to NSAIDs to protect against their possible gastro-duodenal side effects.

An improved rat model for chronic inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is an important cause of chronic disability in humans.

METHODS

We characterized a model of chronic IBD in young male Wistar rats by administering dextran sodium sulfate (DSS: 0%, 0.25%, 0.5%, or 1% in drinking water) for six weeks, with 0.5% DSS for twelve weeks, following DSS cessation or together with treatment with sulfasalazine for the last 6 weeks. We measured gastrointestinal characteristics including stool consistency, blood in stools, small intestine and colon length, intestinal transit and permeability, and gut microbiota, as well as extra-intestinal parameters including oral glucose tolerance, systolic blood pressure, fat and lean mass, and left ventricular stiffness.

RESULTS

At 6 weeks, 0.25-1% DSS produced gastrointestinal changes as diarrhea and blood in stools. At 12 weeks, 0.5% DSS produced chronic and sustained gastrointestinal changes, with marked infiltration of inflammatory cells throughout the gastrointestinal tract and crypt distortion. Firmicutes increased and Bacteroidetes and Actinobacteria decreased in DSS-treated rats. Changes were reversed by DSS cessation or sulfasalazine treatment. Gastrointestinal permeability and extra-intestinal parameters did not change, so DSS changes were limited to the gastrointestinal tract.

CONCLUSION

Chronic 0.5% DSS produces selective and reversible gastrointestinal changes, providing an improved chronic model in rats that mimics human IBD for testing new interventions.

Mechanism of Action of STW 5 in Functional Dyspepsia and IBS: The Origin of Multi-Target

BACKGROUND

STW 5 is a complex herbal combination preparation composed of 9 different herbal extracts. As an herbal medicinal product, this preparation is indicated for treating functional dyspepsia (FD) and irritable bowel syndrome (IBS). Its efficacy and practical applicability was demonstrated in several clinical studies.

SUMMARY

Each herbal constituent of STW 5 has distinct effects on the gastrointestinal tract, and each shows activity through different mechanisms of action: among others, the single extracts have effects on nerves, smooth muscles, epithelial, and inflammatory cells. For example, they have relaxing or tonicizing effects on gastrointestinal muscles, and they counteract inflammation through different physiological systems, contributing to the clinical efficacy through modulation of multiple therapeutic targets. Key Messages: STW 5 is a role model for the concept of multi-targeting in therapy. Especially in complex syndromes such as FD and IBS, simultaneous multi-targeting of different functional causes seems to be a more promising approach than the classical paradigm of one disease - one receptor - one effect.

Evaluating the Multitarget Effects of Combinations through Multistep Clustering of Pharmacological Data: the Example of the Commercial Preparation Iberogast

Herbal combination preparations are widely used in traditional herbal medicine and are even established as modern evidence-based herbal medicinal products. The rationale behind such combinations is often questioned and assessing the contribution of each of the combination partners to overall activity is challenging. STW 5 (Iberogast) is such a combination with confirmed clinical efficacy in functional gastrointestinal disorders. It consists of nine plant extracts responsible for its multitarget function in these multifactorial diseases with their heterogeneous and overlapping pathomechanisms. This makes the combination an ideal candidate for the use of the newly described method of stepwise cluster analysis, a standardized procedure to transfer heterogeneous pharmacological data, from different models, into effect size categories. This allows for a stepwise cluster formation starting from the level of single tests up to the level of different pathomechanisms involved in the development of a certain disease, in this case functional dyspepsia subtypes and irritable bowel syndrome. In the current article, an overview on the pharmacological data on STW 5 and its single components is provided. The data are further analyzed using stepwise cluster formation, resulting in a summary of the different modes of action of STW 5 along with an evaluation of the contribution of the single constituents to the overall multitarget effects of the herbal combination preparation.

Modulation of gastrointestinal motility beyond metoclopramide and domperidone : Pharmacological and clinical evidence for phytotherapy in functional gastrointestinal disorders

The prokinetic cisapride, an important therapeutic option in functional gastrointestinal (GI) disorders, was withdrawn from the market 15 years ago due to rare severe side effects. Likewise in 2014, the use of metoclopramide (MCP) and domperidone in functional GI disorders (FGID) was restricted, consequently leaving a therapeutic gap in clinical practice. A systematic review revealed that the herbal medicinal product (HMP) STW 5 presents a therapeutic option equivalent to MCP and cisapride. STW 5 is the only HMP for which efficacy has been shown in randomized controlled clinical trials (RCTs) in functional dyspepsia and irritable bowel syndrome, based on its multitarget effect on numerous etiological factors. Due to an outstanding favorable safety profile, STW 5 allows an effective and safe use in FGID without a limitation of the duration of the treatment.

Alterations of colonic function in the Winnie mouse model of spontaneous chronic colitis

The Winnie mouse, carrying a missense mutation in Muc2, is a model for chronic intestinal inflammation demonstrating symptoms closely resembling inflammatory bowel disease (IBD). Alterations to the immune environment, morphological structure, and innervation of Winnie mouse colon have been identified; however, analyses of intestinal transit and colonic functions have not been conducted. In this study, we investigated in vivo intestinal transit in radiographic studies and in vitro motility of the isolated colon in organ bath experiments. We compared neuromuscular transmission using conventional intracellular recording between distal colon of Winnie and C57BL/6 mice and smooth muscle contractions using force displacement transducers. Chronic inflammation in Winnie mice was confirmed by detection of lipocalin-2 in fecal samples over 4 wk and gross morphological damage to the colon. Colonic transit was faster in Winnie mice. Motility was altered including decreased frequency and increased speed of colonic migrating motor complexes and increased occurrence of short and fragmented contractions. The mechanisms underlying colon dysfunctions in Winnie mice included inhibition of excitatory and fast inhibitory junction potentials, diminished smooth muscle responses to cholinergic and nitrergic stimulation, and increased number of α-smooth muscle actin-immunoreactive cells. We conclude that diminished excitatory responses occur both prejunctionally and postjunctionally and reduced inhibitory purinergic responses are potentially a prejunctional event, while diminished nitrergic inhibitory responses are probably due to a postjunction mechanism in the Winnie mouse colon. Many of these changes are similar to disturbed motor functions in IBD patients indicating that the Winnie mouse is a model highly representative of human IBD.

NEW & NOTEWORTHY

This is the first study to provide analyses of intestinal transit and whole colon motility in an animal model of spontaneous chronic colitis. We found that cholinergic and purinergic neuromuscular transmission, as well as the smooth muscle cell responses to cholinergic and nitrergic stimulation, is altered in the chronically inflamed Winnie mouse colon. The changes to intestinal transit and colonic function we identified in the Winnie mouse are similar to those seen in inflammatory bowel disease patients.

Dietary protocatechuic acid ameliorates dextran sulphate sodium-induced ulcerative colitis and hepatotoxicity in rats

The present study investigated the antioxidant and anti-inflammatory effects of dietary protocatechuic acid (PCA), a simple hydrophilic phenolic compound commonly found in many edible vegetables, on dextran sulphate sodium (DSS)-induced ulcerative colitis and its associated hepatotoxicity in rats. PCA was administered orally at 10 mg kg(-1) to dextran sulphate sodium exposed rats for five days. The result revealed that administration of PCA significantly (p < 0.05) prevented the incidence of diarrhea and bleeding, the decrease in the body weight gain, shortening of colon length and the increase in colon mass index in DSS-treated rats. Furthermore, PCA prevented the increase in the plasma levels of pro-inflammatory cytokines, markers of liver toxicity and markedly suppressed the DSS-mediated elevation in colonic nitric oxide concentration and myeloperoxidase activity in the treated rats. Administration of PCA significantly protected against colonic and hepatic oxidative damage by increasing the antioxidant status and concomitantly decreased hydrogen peroxide and lipid peroxidation levels in the DSS-treated rats. Moreover, histological examinations confirmed PCA chemoprotection against colon and liver damage. Immunohistochemical analysis showed that PCA significantly inhibited cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein expression in the colon of DSS-treated rats. In conclusion, the effective chemoprotective role of PCA in colitis and the associated hepatotoxicity is related to its intrinsic anti-inflammatory and anti-oxidative properties.

Anti-inflammatory Effects of Herbal Preparations STW5 and STW5-II in Cytokine-Challenged Normal Human Colon Cells

Inflammatory bowel diseases (IBD) are chronic relapsing intestinal disorders characterized by up-regulation of pro-inflammatory cytokines followed by invasion of immune cells to the intestinal lamina propria. Standard therapies consist of anti-inflammatory or immunosuppressive drugs. Since clinical efficiency is not satisfactory and the established drugs have massive side effects, new strategies to treat IBD are required. Herein, we investigate the protective effect of the fixed combination herbal preparations STW5 and STW5-II and the contribution of the corresponding single components in an in vitro inflammation model. The normal human colon epithelial cell line, NCM460, was treated with STW5, STW5-II or their single components for 4 h followed by experimental conditions comparable to induction of colitis. A pro-inflammatory cytokine cocktail consisting of TNF-α, IL-β, and IFN-γ was used to simulate inflammatory stimuli normally caused by immune cells. The effects on NCM460 cells were investigated by enzyme-linked immunoassay and Proteome Profiler^®. Levels of IP-10, MCP-1, I-TAC, Groα, and IL-8 were elevated in chemokine-treated cells compared to untreated cells, but significantly reduced upon pretreatment with STW5 or STW5-II. However, the single compounds revealed only little effects on protein expression. Furthermore, we investigated the effect of both combination preparations on pro-inflammatory transcription factors of the STAT family using Western blot. In addition, we tested the effects on upstream MAPK p38. Both, STW5 and STW5-II did not show any effect on MAPK p38, but were effective in reducing phosphorylated levels of STAT1. In conclusion, both combination preparations act in an anti-inflammatory manner by influencing cytokine secretion via reduced activity of the JAK/STAT1 pathway. Relevant differences between STW5 and STW5-II were not found indicating similar efficacies.

Protective effect of isoquercitrin against acute dextran sulfate sodium-induced rat colitis depends on the severity of tissue damage

BACKGROUND

Isoquercitrin (quercetin-3-O-β-d-glucopyranoside) is a flavonoid that exhibited antioxidant and anti-inflammatory activities in a number of in vitro and in vivo studies. Experimental evidence from rodent models of inflammatory bowel disease is, however, lacking. This study was designed to examine whether isoquercitrin effectively and dose-dependently attenuates acute dextran sulfate sodium (DSS)-induced rat colitis.

METHODS

Wistar rats were divided into negative control group (exposed to vehicle only), positive control group (DSS-induced colitis plus vehicle), low isoquercitrin group (DSS pretreated with isoquercitrin 1mg/kg/day) and high isoquercitrin group (DSS with isoquercitrin 10mg/kg/day). Isoquercitrin was administered daily for 14days, and during the last 7days rats drank DSS solution. The effect of isoquercitrin on DSS-induced colitis was assessed clinically (e.g. disease activity index), biochemically (tissue myeloperoxidase activity, local cyclooxygenase-2 expression), using histology (standard hematoxylin-eosin-based histomorphometry, immunohistochemical detection of inducible nitric oxide synthase) and hematology (blood count).

RESULTS

Isoquercitrin dose-dependently ameliorated whole colon shortening and mitigated DSS-induced expression of cyclooxygenase-2 and inducible nitric oxide synthase in the descending segment of the organ. However, when different parts of colon were assessed histomorphometrically, the results did not globally support the protective role of this flavonoid. Tissue healing trends observable in the descending colon were not apparent in the rectum, where histological damage was most severe.

CONCLUSIONS

We surmise that isoquercitrin may be effective in the prevention of acute colitis. Besides being dose-dependent, the potency of orally administered isoquercitrin may depend on the severity of tissue damage and/or on the site of its action.

Anti-inflammatory Actions of (+)-3'α-Angeloxy-4'-keto-3',4'-dihydroseselin (Pd-Ib) against Dextran Sulfate Sodium-Induced Colitis in C57BL/6 Mice

The immunoregulatory protective properties of (+)-3'α-angeloxy-4'-keto-3',4'-dihydroseselin (Pd-Ib) isolated from Bupleurum malconense has not been reported. In the present study, the therapeutic effect of Pd-Ib (30, 60, and 120 mg/kg/day) was examined in a mouse model of dextran sulfate sodium (DSS)-induced acute colitis. Administration of Pd-Ib significantly reduced the disease activity index, inhibited the shortening of colon length, reduced colonic tissue damage, and suppressed colonic myeloperoxidase activity and nitric oxide levels in mice with DSS-induced colitis. Moreover, Pd-Ib greatly suppressed the secretion of pro-inflammatory cytokines TNF-α, IFN-γ, IL-6, and IL-17A while enhancing the level of anti-inflammatory cytokine IL-4. The protein levels of phosphorylated STAT3 (p-STAT3) and phosphorylated p38 (p-p38) were down-regulated in the colonic tissues of DSS-treated mice. Importantly, the anti-inflammatory effect of Pd-Ib against acute colitis was comparable to the anti-inflammatory sulfa drug sulfasalazine (300 mg/kg). Furthermore, the in vitro study showed that the inhibitory effect of Pd-Ib on p-STAT3 and IL-6 protein levels was accompanied by the reduction of MAPKs (JNK and p38). In conclusion, this study suggested that Pd-Ib attenuated DSS-induced acute colitis via the regulation of interleukins principally through the STAT3 and MAPK pathways.

Modulation in Natriuretic Peptides System in Experimental Colitis in Rats

BACKGROUND

Renin-angiotensin system is involved in the pathophysiology of colonic inflammation. However, there are a few reports about modulation of natriuretic peptide system.

AIMS

This study investigates whether a local atrial natriuretic peptide (ANP) system exists in rat colon and whether ANP plays a role in the regulation of colonic motility in experimental colitis rat model.

METHODS

Experimental colitis was induced by an intake of 5 % dextran sulfate sodium (DSS) dissolved in tap water for 7 days. After rats were killed, plasma hormone concentrations and mRNAs for natriuretic peptide system were measured. Functional analysis of colonic motility in response to ANP was performed using taenia coli.

RESULTS

DSS-treated colon showed an increased necrosis with massive infiltration of inflammatory cells. The colonic natriuretic peptide receptor-A mRNA level and particulate guanylyl cyclase activity in response to ANP from colonic tissue membranes were higher, and the mRNA levels of ANP and natriuretic peptide receptor-B were lower in DSS-treated rats than in control rats. ANP decreased the frequency of basal motility in a dose-dependent manner but did not change the amplitude. The inhibitory responses of frequency of basal motility to ANP and 8-bromo-cGMP were enhanced in DSS-treated rat colon.

CONCLUSION

In conclusion, augmentation of inhibitory effect on basal motility by ANP in experimental colitis may be due an increased expression of colonic natriuretic peptide receptor-A mRNA. These data suggest that local natriuretic peptide system is partly involved in the pathophysiology of experimental colitis.

Favorable results from the use of herbal and plant products in inflammatory bowel disease: evidence from experimental animal studies

The use of herbal therapy for inflammatory bowel disease is increasing worldwide. The aim of this study was to review the available literature on the efficacy of herbal therapy in experimental colitis. All relevant studies published in Medline and Embase up to June 2015 have been reviewed. The results of bowel histology and serum parameters have been recorded. A satisfactory number of published experimental studies, and a quite large one of both herbal and plant products tested in different studies have been reported. The results showed that in the majority of the studies, herbal therapy reduced the inflammatory activity of experimental colitis and diminished the levels of many inflammatory indices, including serum cytokines and indices of oxidative stress. The most promising plant and herbal products were tormentil extracts, wormwoodherb, Aloe vera, germinated barley foodstuff, curcumin, Boswellia serrata, Panax notoginseng, Ixeris dentata, green tea, Cordia dichotoma, Plantago lanceolata, Iridoidglycosides, and mastic gum. Herbal therapies exert their therapeutic benefit via various mechanisms, including immune regulation, anti-oxidant activity, inhibition of leukotriene B4 and nuclear factor-κB, and antiplatelet activity. Large, double-blind clinical studies assessing these natural substances should be urgently conducted.

A multi-component herbal preparation, STW 5, shows anti-apoptotic effects in radiation induced intestinal mucositis in rats

PURPOSE

Intestinal mucositis is a common adverse effect in patients undergoing radiotherapy and constitutes a treatment-limiting condition. Since no agents are yet known that can adequately guard against its development, the search continues to find safe and effective measures. The present study was intended to investigate whether the herbal preparation, STW 5, could offer a potentially effective agent in this respect.

METHODS

Intestinal mucositis was induced in rats by exposing them to whole body gamma-irradiation (6 Gy). Rats were treated orally with STW 5 (5 or 10 ml/kg) for five days before and two days after irradiation. One day later, rats were sacrificed and segments of small intestine were examined histologically. Intestinal homogenates and serum samples were used to assess relevant parameters for apoptosis and different markers for inflammation and oxidative stress.

RESULTS

Exposure to radiation produced dose-dependent extents of intestinal injury associated with apoptotic changes with high radiation levels. Apoptosis was associated with an increase in cytosolic calcium, depletion of mitochondrial cytochrome c, B-cell lymphoma-2 and complex I. Oxidative stress parameters (reduced glutathione, thiobarbituric acid reactive substance and total nitrate/nitrite) were deranged. Inflammation markers (tumor necrosis factor and myeloperoxidase) and indices of intestinal damage (serum diamine oxidase) were increased. STW 5 protected to a large extent against histological changes and counteracted the deranged parameters.

CONCLUSION

The findings provide experimental evidence for the potential beneficial use of STW5 in protecting against the development of radiation-induced intestinal mucositis and associated changes in tissue biomarkers.

Murine Models of Inflammatory Bowel Disease (IBD)

Animal models of human disease are a critical tool in both basic research and drug development. The results of preclinical efficacy studies often inform progression of therapeutic candidates through the drug development pipeline; however, the extent to which results in inflammatory bowel disease (IBD) models predict human drug response is an ongoing concern. This review discusses how murine models are currently being used in IBD research. We focus on the considerations and caveats for commonly used models in preclinical efficacy studies and discuss the value of models that utilize specific pathogenic pathways of interest rather than model all aspects of human disease.

Clinical and structural effects of traditional Chinese medicine and the herbal preparation, Iberogast, in a rat model of ulcerative colitis

Plant-sourced formulations such as Iberogast and the traditional Chinese medicine formulation, Cmed, purportedly possess anti-inflammatory and radical scavenging properties. We investigated Iberogast and Cmed, independently, for their potential to decrease the severity of the large bowel inflammatory disorder, ulcerative colitis. Sprague Dawley rats (n = 8/group) received daily 1 mL gavages (days 0-13) of water, Iberogast (100 μL/200 μL), or Cmed (10 mg/20 mg). Rats ingested 2% dextran sulfate sodium or water ad libitum for 7 days commencing on day 5. Dextran sulfate sodium administration increased disease activity index scores from days 6 to 12, compared with water controls (P < .05). On day 10, 200 μL Iberogast decreased disease activity index scores in colitic rats compared with colitic controls (P < .05). Neither Iberogast nor Cmed achieved statistical significance for daily metabolic parameters or colonic crypt depth. The therapeutic effects of Iberogast and Cmed were minimal in the colitis setting. Further studies of plant extracts are required investigating greater concentrations and alternative delivery systems.

Investigation of STW 5 (Iberogast®) preventive effects in experimental sepsis

CONTEXT

STW 5 (Iberogast(®)) is a well known herbal combination drug containing glycosides and flavonoids for which multiple pharmacological properties have been shown.

OBJECTIVE

In this study, attempts were made to assess whether STW 5, an aqueous ethanol solution, has a preventive effect against liver and lung pathological damage in rats after experimental induction of sepsis [cecal ligation and puncture (CLP)].

MATERIALS AND METHODS

Experimental sepsis was induced in rats using CLP operation. The rats (n = 36) were divided into six groups (six/group): Sham-operated (SOP); CLP; CLP + STW 5 (2.5, 5 and 10 mg/kg) and CLP + indomethacin. The drugs were injected intraperitoneally immediately after sepsis induction.

RESULTS

It was found that induction of sepsis 24 h after CLP was associated with significant liver and lung damage, also remaining after STW 5 administration.

DISCUSSION AND CONCLUSION

It appears that STW 5, which has a pronounced efficacy in functional gastro-intestinal diseases, has no effect on septic liver and lung damage in the CLP rat model.

Kolaviron, a natural antioxidant and anti-inflammatory phytochemical prevents dextran sulphate sodium-induced colitis in rats

The beneficial effects of kolaviron, a natural biflavonoid from the seeds of Garcinia kola, have been attributed mainly to its antioxidant and anti-inflammatory effects. This study investigated these effects on dextran sulphate sodium (DSS)-induced ulcerative colitis in rats. Sulfasalazine served as standard reference in this study. Kolaviron and sulfasalazine were separately co-administered orally at 200 mg/kg and 500 mg/kg, respectively, to dextran sulphate sodium-exposed rats for 5 days. The result indicated that kolaviron or sulfasalazine significantly prevented DSS-induced body weight loss as well as the incidence of diarrhoea and bleeding in DSS-exposed rats. Kolaviron suppressed the DSS-mediated increase in colonic nitric oxide concentration and myeloperoxidase activity and significantly prevented the increase in inflammatory mediators, interleukin-1β and tumour necrosis factor alpha, in the colon of DSS-treated rats. The significant depletion in colonic antioxidant status in rats exposed to DSS alone was evident by marked reduction in colonic catalase and glutathione S-transferase activities as well as glutathione content, leading to elevated hydrogen peroxide and lipid peroxidation levels. Histopathologically, DSS alone resulted in severe epithelial erosion, total absence of goblet cells, destruction of the crypts, necrotic and distorted glands, accompanied by marked cellular mononuclear cells infiltration. However, administration of kolaviron and sulfasalazine ameliorated DSS-induced colitis by increasing the antioxidant status decreased hydrogen peroxide and lipid peroxidation levels and attenuated the adverse effect of DSS on colon architecture. In conclusion, the anti-colitis effect of kolaviron is related to its intrinsic anti-inflammatory and anti-oxidative properties.