Spasmolytic and tonic effect of Iberogast (STW 5) in intestinal smooth muscle

Herbal Amara extract induces gastric fundus relaxation via inhibition of the M2 muscarinic receptor

BACKGROUND

Impaired gastric accommodation is one of the most frequent symptoms of functional dyspepsia. The safety and efficacy of conventional treatments remain to be proven and alternative herbal therapies have been proposed to alleviate gastrointestinal symptoms. This preclinical study examined the role of herbal Amara extract (containing Artemisia absinthium, Centaurium erythraea, Cichorium intybus, Gentiana lutea, Juniperus communis, Achillea millefolium, Peucedanum ostruthium, Salvia officinalis, and Taraxacum extracts) on gastric (fundus) accommodation and the possible implication of muscarinic receptors in its regulation.

METHODS

The effect of Amara extract on fundus motility was investigated in organ baths of smooth muscle strips isolated from the fundus of guinea pigs, and the role of the muscarinic receptor pathway was evaluated using functional and radioligand binding assays in cell lines expressing the M2 or M3 muscarinic receptor.

KEY RESULTS

Amara extract inhibited carbachol-induced contraction of guinea pig smooth muscle strips in a dose-dependent manner. This relaxant effect was not affected by the M3 antagonist J-104129. Amara extract also inhibited M2, but not M3, receptor activity in CHO-K1 cells (IC50 219 μg mL-1), and specifically bound the M2 receptor (IC50 294 μg mL-1). Of the nine herbal components of Amara extract, Juniperus communis, P. ostruthium, and Salvia officinalis inhibited M2 receptor activity (IC50 32.0, 20.8, and 20.1 μg mL-1, respectively), and P. ostruthium was sufficient to reverse carbachol-induced ex vivo contraction of guinea pig fundic smooth muscles.

CONCLUSION AND INFERENCES

Amara extract relaxes gastric smooth muscles by inhibiting the M2 muscarinic receptor. This study suggests the potential benefit of Amara extract for patients with impaired gastric accommodation.

Pharmacologic treatment of irritable bowel syndrome. Position statement of the Asociación Mexicana de Gastroenterología, 2024

INTRODUCTION

The aim of this position statement is to provide health professionals with an updated and evidence-based guideline for the pharmacologic management of irritable bowel syndrome (IBS) in Mexico.

MATERIAL AND METHODS

A literature review was conducted that included relevant guidelines and studies, up to the date of its publication. The mechanism of action, specific indications in IBS, safety profile, and availability of each therapeutic class were evaluated. The recommendations were developed by 14 experts, considering the clinical reality of IBS patients in Mexico.

RESULTS

Specific recommendations were issued for each class. Antispasmodics (alone or combined) are used as first-line therapy for pain management, whereas antidiarrheals, such as loperamide, are used for reducing diarrhea in diarrhea-predominant IBS (IBS-D) and laxatives are used for constipation in constipation-predominant IBS (IBS-C). 5-HT4 agonists (prucalopride and mosapride) are recommended in IBS-C and 5-HT3 antagonists (ondansetron) are recommended in IBS-D. Linaclotide is the only secretagogue available in Mexico and is used in IBS-C. Rifaximin-alpha stands out for its efficacy in a subgroup of patients with IBS-D or mixed IBS. Probiotics are conditionally recommended as adjuvant therapy due to heterogeneous evidence. Neuromodulators (tricyclic antidepressants, selective serotonin reuptake inhibitors, etc.) are recommended as second-line treatment for pain management. Mesalazine can be used in IBS-D, but the corresponding evidence is weak.

CONCLUSION

Overall, these recommendations provide a solid framework for personalizing treatment, based on the clinical characteristics of the Mexican patient with IBS.

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.

Pharmacological disadvantages in the spasmolytic effects by using the mixture known as "three toronjiles" in folk medicine

ETHNOPHARMACOLOGY RELEVANCE

In Mexico, Agastache mexicana subsp. mexicana (PT) and subsp. xolocotziana (WT), and Dracocephalum moldavica (BT), are used together as the "three toronjiles" to treat gastrointestinal spasms.

AIM OF STUDY

To evaluate if the spasmolytic activity of these three medicinal species is better in combination or in an individual manner.

MATERIALS AND METHODS

Spasmolytic effect of PT, WT and BT alone or combinate were evaluated in rings of the guinea-pig ileum contracted with potassium chloride (KCl), electrical field stimulation (EFS), or acetylcholine (ACh). Chemical analysis by thin layer and ultra-high pressure liquid chromatography of the aqueous extracts of each species were done for their comparison, and their acute toxicity were determined in mice.

RESULTS

PT and WT diminished in a dose-dependent manner the contractions induced by KCl, EFS, and ACh. Whereas BT did not altered contractions in any experimental protocol. A combination of the PT (EC50) and WT (EC50) diminished the contractions induced by KCl or EFS. Interestingly, the addition of BT extract (10 μg/ml) to the combination (PT EC30 + WT EC30) blocked the inhibitory effect produced on the contracted tissue in the presence of KCl, EFS, or ACh. Moreover, addition of BT extract (100 μg/ml) to the same combination blocked the inhibitory effect on the pre-contracted tissue only in the presence of EFS. None of the aqueous extracts produced toxicity in its individual administration in mice. Chemical analysis demonstrated similarities between PT and WT, but differences with BT.

CONCLUSIONS

The results of this study confirmed that either combined or by themselves aqueous extracts of PT and WT produced a spasmolytic action on guinea pig ileum, suggesting that this combination of medicinal plants could relieve gastrointestinal diseases in human, but when BT aqueous extract is added to those obtained with PT and WT, the spasmolytic activity diminished or even was blocked. Our results give evidence that mixture of several plants might produce disadvantages in the medicinal properties of their individual activity.

Functional gastrointestinal diseases: mechanisms of development and principles of multitarget therapy

Currently, functional dyspepsia (FD) and irritable bowel syndrome (IBS) are among the most common nosological  units in the structure of functional gastrointestinal  diseases in adults. An important problem of treatment of these diseases at the current stage of medicine is low efficiency of monotarget drugs, which is determined by multicomponent pathogenesis. Indeed, the currently available  methods of drug treatment of FD and IBS have suboptimal  efficacy, as illustrated  by recent meta-analyses demonstrating high rates of NNT (the average number of patients who need to be treated to achieve a certain favorable outcome). In addition, the frequent “overlap” of these diseases forces clinicians to prescribe several drugs with different pharmacological actions to the patient, which inevitably leads to a decrease in compliance. The optimal strategy for managing patients with FD and IBS is the tactics of multitarget drugs that act on several links in the pathogenesis of these pathologies and have a significant evidence base in the effectiveness and safety of use. STW 5 (Iberogast®), included  in the clinical  guidelines  of the Russian Gastroenterological Association on the diagnosis and treatment of patients with FD, published in 2017, has the above-mentioned characteristics, as well as the clinical guidelines of the Russian Gastroenterological Association in collaboration with the Russian Association of Coloproctologists on the diagnosis and treatment of IBS, published in 2021. The clinical effectiveness of Iberogast in the treatment of FD and IBS has been demonstrated in a number of randomized trials, the results of which showed high efficacy of the drug and its good tolerability.

Medical Therapies for Diarrhea-Predominant Irritable Bowel Syndrome

Diarrhea-predominant irritable bowel syndrome is a common functional gastrointestinal disorder that manifests with abdominal pain and diarrheal bowel patterns, without structural explanation. Diarrhea-predominant irritable bowel syndrome is a heterogeneous condition resulting from diverse pathophysiologic processes. Treatment strategies with varied mechanisms of action are beneficial in its management. The clinician must become familiar with a multi-dimensional approach to irritable bowel syndrome. The 3 approved medications are central to disease management. Effective treatment uses off-label medications and emerging therapies and a growing number of over-the-counter and supplemental agents to optimize symptom improvement for the patient with diarrhea-predominant irritable bowel syndrome.

Herbal medicines in functional dyspepsia-Untapped opportunities not without risks

BACKGROUND

Contemporary treatments for functional dyspepsia have limitations. Herbal medicine has been suggested as adjunctive treatment. With growing scientific recognition and public interests, an in-depth review of this is timely.

AIMS/PURPOSE

To evaluate the therapeutic potential and problems that may be associated with the adoption of herbal medicines in functional dyspepsia.

METHODS

We reviewed the treatment landscape of functional dyspepsia and assessed the scientific community's interest in herbal medicine. Preclinical pharmacological and clinical trial data were reviewed for several herbal medicines available in the market. Challenges associated with adoption of herbal medicine in mainstream medicine were critically evaluated.

RESULTS

We found that herbal medicines frequently comprise a combination of herbs with multiple reported pharmacological effects on gastrointestinal motility and secretory functions, as well as cytoprotective and psychotropic properties. We identified a number of commercially available herbal products that have undergone rigorous clinical trials, involving large numbers of well-defined subjects, reporting both efficacy and safety for functional dyspepsia. Persisting concerns include lack of rigorous assessments for majority of products, toxicity, consistency of ingredients, dose standardizations, and quality control. We provide a quality framework for its evaluation.

CONCLUSIONS

We commend herbal medicine as a viable future option in managing functional dyspepsia. An attractive appeal of herbal medicine is the prospect to simultaneously target multiple pathophysiological mechanisms. Wider adoption and acceptance of herbal medicines in treatment algorithms of functional dyspepsia will require the application of the scientific rigor expected of chemical therapies, to all stages of their development and evaluation.

Insight into glycogen synthase kinase-3β inhibitory activity of phyto-constituents from Melissa officinalis: in silico studies

Over activity of Glycogen synthase kinase-3β (GSK-3β), a serine/threonine-protein kinase has been implicated in a number of diseases including stroke, type II diabetes and Alzheimer disease (AD). This study aimed to find novel inhibitors of GSK-3β from phyto-constituents of Melissa officinalis with the aid of computational analysis. Molecular docking, induced-fit docking (IFD), calculation of binding free energy via the MM-GBSA approach and Lipinski's rule of five (RO5) were employed to filter the compounds and determine their druggability. Most importantly, the compounds pIC50 were predicted by machine learning-based model generated by AutoQSAR algorithm. The generated model was validated to affirm its predictive model. The best model obtained was Model kpls_desc_38 (R2 = 0.8467 and Q2 = 0.8069), and this external validated model was utilized to predict the bioactivities of the lead compounds. While a number of characterized compounds from Melissa officinalis showed better docking score, binding free energy alongside adherence to RO5 than co-cystallized ligand, only three compounds (salvianolic acid C, ellagic acid and naringenin) showed more satisfactory pIC50. The results obtained in this study can be useful to design potent inhibitors of GSK-3β.

STW5 (Iberogast®) for constipation in Parkinson's disease

BACKGROUND

Chronic constipation is one of the most frequent non-motor symptoms in Parkinson's disease (PD), and impairs patients' quality of life.

OBJECTIVE

The aim of this pilot study was to assess the efficacy and the tolerability of STW5, a phytotherapeutic agent composed of nine plant extracts, for the treatment of constipation in patients with PD.

METHODS

We carried out an open monocentric study of STW5 in the treatment of constipation in parkinsonian patients. Forty-four PD patients with a mean age of 66.4±7.3 years (range, 35-78), a mean disease duration of 12.6±5.4 years (range, 3-27) and with constipation defined by Rome III criteria for functional constipation were included. Following a two-week laxative-free baseline period, all the patients were treated with 20 drops STW5 t.i.d for 28 days, after a seven-day titration period. Treatment efficacy was defined as marked improvement of stool frequency with an increase of three exonerations during the last week of treatment when compared to the week before the initiation of treatment. Responder rate for stool frequency was estimated at 29/45 patients.

RESULTS

An increase of stool frequency≥three eliminations/week was observed in only four out of 44 patients (9.0%) at the end of the study. The only significant difference observed before and after treatment was a decrease in stool consistency (P=0.0272).

CONCLUSIONS

Our results suggest that STW5 has a safety profile but is not effective as a phytotherapeutic agent in constipation related to Parkinson's disease.

Application of an in vitro digestion model to study the metabolic profile changes of an herbal extract combination by UHPLC-HRMS

BACKGROUND

STW 5 is a fixed herbal combination containing extracts from nine medicinal plants: bitter candytuft, greater celandine, garden angelica roots, lemon balm leaves, peppermint leaves, caraway fruits, licorice roots, chamomile flowers, and milk thistle fruit. STW 5 is a clinically proven treatment for functional dyspepsia and irritable bowel syndrome.

PURPOSE

Using a static in vitro method, we simulated oral, gastric, and small intestinal digestion and analyzed the metabolic profile changes by UHPLC-HRMS to determine the impact of oro-gastro-intestinal digestion on STW 5 constituents.

STUDY DESIGN AND METHODS

STW 5 was incubated according to the InfoGest consensus method. Samples of each digestive phase were analyzed by UHPLC-HRMS in ESI positive and negative modes. After data processing, background subtraction, and normalization, the peak areas of detectable compounds were compared to untreated reference samples and recovery ratios were calculated to monitor the metabolic profile of STW 5 during simulated digestion.

RESULTS

Although the levels of some constituents were reduced, we did not observe complete degradation of any of the constituents of STW 5 upon in vitro digestion. We did not detect any new metabolites beyond increased levels of caffeic acid and liquiritigenin due to degradation of progenitor compounds. Changes observed in intestinal bioaccessibility ratios were mainly a result of isomerization, hydrolysis, protein binding, and low water solubility.

CONCLUSION

The majority of STW 5 constituents are stable towards simulated in vitro digestion and can reach the colon to interact with gut microbiota if they remain unabsorbed in the upper intestinal tract.

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.

Western herbal medicines in the treatment of irritable bowel syndrome: A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy of Western herbal medicines in the treatment of irritable bowel syndrome (IBS).

DESIGN

A computer-based search of MEDLINE, EMBASE, CINAHL, AMED, GreenFILE, Health Source: Nursing/Academic Edition, and the Cochrane Library was conducted. A hand-search of the bibliographies of relevant papers and previous meta-analyses and reviews was also undertaken. Trials were included in the review if they were double-blind and placebo-controlled investigating the effects of Western herbal medicines on IBS-related symptoms or quality of life. There were no language restrictions. Eligibility assessment and data extraction were performed by two independent researchers. For herbal medicines where there was more than 1 trial of similar design, data were synthesised using relative risk of symptoms improving using the random effects model.

RESULTS

Thirty-three trials were identified that met all eligibility criteria. Seventeen of these evaluated peppermint essential oil, fifteen other Western herbal medicines, and one trial evaluated peppermint oil in one arm and aniseed essential oil in the other arm. Eighteen different herbal preparations were evaluated in these trials. Data suggests that a number of Western herbal medicines may provide relief of IBS symptoms. Meta-analyses suggest that peppermint essential oil is both efficacious and well-tolerated in the short-term management of IBS. Aloe vera and asafoetida also demonstrated efficacy in reducing global IBS symptoms in meta-analyses. The herbal formulas STW 5, STW 5-II and Carmint, along with Ferula assa-foetida, Pimpenella anisum oil, the combination of Curcumin and Foeniculum vulgare oil, and the blend of Schinopsis lorentzii, Aesculus hippocastanum, and peppermint essential oil also demonstrated efficacy in rigorously-designed clinical trials.

CONCLUSION

A number of Western herbal medicines show promise in the treatment of IBS. With the exception of peppermint essential oil, Aloe vera, and asafoetida, however, none of the positive trials have been replicated. This lack of replication limits the capacity to make definitive statements of efficacy for these herbal medicines.

Synergy quantifications to identify individual contributions of combination partners to the overall activity - The example of STW 5

BACKGROUND

The rationale of combinations of plant extracts is often questioned. The common argument for combinations is a higher efficacy of the combination partners by multitargeting and the elimination of adverse events.

AIM

STW5, a well-known fixed herbal multicomponent preparation, is recommended in the German treatment guidelines for functional gastrointestinal diseases. The study assessed effects of STW5, its single plant components and combinations thereof on different targets to identify synergistic, additive or antagonistic effects of the combination partners.

STUDY DESIGN/METHODS

STW5, its nine components and triple combinations thereof were investigated in two in vitro models - human esophageal epithelial cells (Het1A) and intestinal smooth muscle cells (HISMC) - in comparison to Omeprazole (OM) for the release of interleukin 8 (IL-8) as surrogate for inflammation and of Ca²⁺ as surrogate for motion, under non-inflammatory and inflammatory (Capsaicin 80 µM (CAP)) conditions. The combination index (CI) of triple combinations was calculated to assess synergistic, antagonistic and additive effects.

RESULTS

In Het-1A cells, STW5 showed, under non-inflammatory as well as inflammatory conditions, releases of IL-8 (49.3 ± 4.2 pg/ml, 33.7 ± 2 pg/ml) comparable to the untreated control (46.3 ± 4.8 pg/ml). CAP increased IL-8 releases to 85.8 ± 14 pg/ml (p < 0.005). Among the single plant extracts the Iberis amara extract (IBE) induced high IL-8 releases under non-inflammatory (441 ± 177 pg/ml) and inflammatory (625± 121 pg/ml) conditions. The Silybum marianum (L.) extract (SM) reduced releases up to 20.1 ± 8 pg/ml (inflammation). The CI-values of triple combinations with IBE ranged from high synergy (CI<0.03) to antagonism (CI:480). Within the triple combinations SM was the most effective combination partner to reduce IL-8. The combination of Angelica archangelica (L.)/Carum carvi (L.) was also effective. In HISMCs, STW5 induced concentration dependent higher Ca²⁺-releases. Only Melissa officinalis (L.) (MO) induced high Ca²⁺- releases in HISMCs.

CONCLUSION

In Het-1A, STW5 inhibited Il-8 releases, although one of its components (IBE) stimulated IL-8 strongly. The combination partners in STW5 assured an overall marked anti-inflammatory action. In the triple combinations SM was identified as most important combination partner for the IL-8 reduction. CI-measurements can support the identification of active combination partners in a multicomponent preparation and can give directions towards the search for multitarget effects.

Management Options for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is associated with diverse pathophysiologic mechanisms. These mechanisms include increased abnormal colonic motility or transit, intestinal or colorectal sensation, increased colonic bile acid concentration, and superficial colonic mucosal inflammation, as well as epithelial barrier dysfunction, neurohormonal up-regulation, and activation of secretory processes in the epithelial layer. Novel approaches to treatment include lifestyle modification, changes in diet, probiotics, and pharmacotherapy directed to the motility, sensation, and intraluminal milieu of patients with IBS. Despite recent advances, there is a need for development of new treatments to relieve pain in IBS without deleterious central or other adverse effects.

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.

Probiotics, fibre and herbal medicinal products for functional and inflammatory bowel disorders

Functional bowel disorders (FBD), mainly irritable bowel syndrome (IBS) and functional constipation (FC, also called chronic idiopathic constipation), are very common worldwide. Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, although less common, has a strong impact on patients' quality of life, as well as being highly expensive for our healthcare. A definite cure for those disorders is still yet to come. Over the years, several therapeutic approaches complementary or alternative to traditional pharmacological treatments, including probiotics, prebiotics, synbiotics, fibre and herbal medicinal products, have been investigated for the management of both groups of diseases. However, most available studies are biased by several drawbacks, including small samples and poor methodological quality. Probiotics, in particular Saccharomyces boulardii and Lactobacilli (among which Lactobacillus rhamnosus), synbiotics, psyllium, and some herbal medicinal products, primarily peppermint oil, seem to be effective in ameliorating IBS symptoms. Synbiotics and fibre seem to be beneficial in FC patients. The probiotic combination VSL#3 may be effective in inducing remission in patients with mild-to-moderate ulcerative colitis, in whom Escherichia coli Nissle 1917 seems to be as effective as mesalamine in maintaining remission. No definite conclusions can be drawn as to the efficacy of fibre and herbal medicinal products in IBD patients due to the low number of studies and the lack of randomized controlled trials that replicate the results obtained in the individual studies conducted so far. Thus, further, well-designed studies are needed to address the real role of these therapeutic options in the management of both FBD and IBD.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

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.

Irritable Bowel Syndrome: Pathophysiology and Current Therapeutic Approaches

Irritable bowel syndrome (IBS) is a prevalent condition affecting 10-20% of adults in most countries; IBS results in significant morbidity and health care costs. IBS is a disorder of the brain-gut axis, and recent insights into the pathophysiological mechanisms include altered bile acid metabolism, neurohormonal regulation, immune dysfunction, alterations in the epithelial barrier, and secretory properties of the gut. There remains a significant unmet need for effective treatments, particularly for the pain component of IBS, although the introduction of drugs directed at secretion, motility, and a nonabsorbable antibiotic provides an option for the bowel dysfunction in IBS.

In vitro spontaneous contractile activity of colonic smooth muscle in naive Lewis rats: Acute effect of gonadal hormones

OBJECTIVE

Functional gastrointestinal disorders affect females more often. Changes in colonic motility may be etiological co-factors for the clinical symptoms. The aim of the present study was to analyze the influence of gonadal hormones on colonic contractile activity.

METHODS

In vitro measurements of colonic contractile activity in longitudinal smooth muscle strips of female and male Lewis rats were performed in an organ chamber experiment. After the administration of a gonadal hormone estradiol [EST], progesterone [PROG] and testosterone [TEST]) or ethanol solution as control, stimulation with acetylcholine (ACh) or inhibition with norepinephrine (NE) was performed.

RESULTS

Compared to the smooth muscle strips of male rats, significantly higher spontaneous colonic contractile activity (SCCA) was observed in female animals. Increasing doses of ACh showed the progressive stimulation of SCCA whereas rising doses of NE resulted in a stepwise inhibition of SCCA, respectively. EST superfusion displayed an inhibitory effect on SCCA in both sexes and inhibited the ACh effect in female rats. Similarly, acute superfusion with high-dose PROG inhibited SCCA in females. Acute TEST superfusion inhibited SCCA in males and led to significant higher colonic contractile activity in males following subsequent stimulation with ACh. In female rats, the inhibitory effect of NE was reduced by prior exposure to TEST.

CONCLUSION

In our in vitro study the acute exposure of colonic smooth muscle tissue to gonadal hormones led to sex-dependent changes in SCCA and translated in a modified response of smooth muscle strips to both pro-contractile and anti-contractile neurotransmitters.

Medicinal plants--prophylactic and therapeutic options for gastrointestinal and respiratory diseases in calves and piglets? A systematic review

BACKGROUND

Gastrointestinal and respiratory diseases in calves and piglets lead to significant economic losses in livestock husbandry. A high morbidity has been reported for diarrhea (calves ≤ 35%; piglets ≤ 50%) and for respiratory diseases (calves ≤ 80%; piglets ≤ 40%). Despite a highly diverse etiology and pathophysiology of these diseases, treatment with antimicrobials is often the first-line therapy. Multi-antimicrobial resistance in pathogens results in international accordance to strengthen the research in novel treatment options. Medicinal plants bear a potential as alternative or additional treatment. Based on the versatile effects of their plant specific multi-component-compositions, medicinal plants can potentially act as 'multi-target drugs'. Regarding the plurality of medicinal plants, the aim of this systematic review was to identify potential medicinal plant species for prevention and treatment of gastrointestinal and respiratory diseases and for modulation of the immune system and inflammation in calves and piglets.

RESULTS

Based on nine initial sources including standard textbooks and European ethnoveterinary studies, a total of 223 medicinal plant species related to the treatment of gastrointestinal and respiratory diseases was identified. A defined search strategy was established using the PRISMA statement to evaluate 30 medicinal plant species starting from 20'000 peer-reviewed articles published in the last 20 years (1994-2014). This strategy led to 418 references (257 in vitro, 84 in vivo and 77 clinical trials, thereof 48 clinical trials in veterinary medicine) to evaluate effects of medicinal plants and their efficacy in detail. The findings indicate that the most promising candidates for gastrointestinal diseases are Allium sativum L., Mentha x piperita L. and Salvia officinalis L.; for diseases of the respiratory tract Echinacea purpurea (L.) MOENCH, Thymus vulgaris L. and Althea officinalis L. were found most promising, and Echinacea purpurea (L.) MOENCH, Camellia sinensis (L.) KUNTZE, Glycyrrhiza glabra L. and Origanum vulgare L. were identified as best candidates for modulation of the immune system and inflammation.

CONCLUSIONS

Several medicinal plants bear a potential for novel treatment strategies for young livestock. There is a need for further research focused on gastrointestinal and respiratory diseases in calves and piglets, and the findings of this review provide a basis on plant selection for future studies.

Iberis amara Extract Induces Intracellular Formation of Reactive Oxygen Species and Inhibits Colon Cancer

Massively increasing global incidences of colorectal cancer require efficient treatment and prevention strategies. Here, we report unexpected anticancerogenic effects of hydroethanolic Iberis amara extract (IAE), which is known as a widely used phytomedical product for treating gastrointestinal complaints. IAE significantly inhibited the proliferation of HT-29 and T84 colon carcinoma cells with an inhibitory concentration (IC₅₀) of 6 and 9 μg/ml, respectively, and further generated inhibitory effects in PC-3 prostate and MCF7 breast cancer cells. Inhibition of proliferation in HT-29 cells was associated with a G2/M phase cell cycle arrest including reduced expression of various regulatory marker proteins. Notably, in HT-29 cells IAE further induced apoptosis by intracellular formation of reactive oxygen species (ROS). Consistent with predictions derived from our in vitro experiments, bidaily oral gavage of 50 mg/kg of IAE over 4 weeks resulted in significant inhibition of tumor growth in a mouse HT-29 tumor xenograft model. Taken together, Iberis amara extracts could become useful alternatives for preventing and treating the progression of colon cancer.

The Pharmacological Effects of Benachio-F(®) on Rat Gastrointestinal Functions

Functional dyspepsia (FD) is a prevalent idiopathic upper gastrointestinal (GI) disorder characterized by diverse symptomatology including epigastric pain or discomfort, postprandial fullness, and early satiety. Although its pathophysiological mechanisms have not yet been fully established, the available studies suggest that the etiology of FD is invariably multifactorial. Benachio-F(®) (BF) is a proprietary liquid formulation of 7 herbal extracts that has been proposed to address this multifactorial etiology using multi-drug phytotherapy. The pharmacological effects of BF, in comparison with those of two other herbal products (Whalmyungsu(®); WM and Iberogast(®); IB) were evaluated in rats. In a laparotomy-induced rat model of delayed GI transit, BF significantly accelerated the delayed gastric emptying caused by morphine, apomorphine, and cisplatin, and also significantly increased mean gastric transit, as compared to the control animals. BF markedly increased gastric accommodation in rats and produced higher gastric volume values than did the control treatment. The effects of BF were generally comparable or superior to those of WM and IB in these models. Furthermore, BF significantly stimulated biliary flow, as compared to the control treatment. These results indicated that BF might have great potential as an effective phytotherapeutic agent capable of reducing GI symptoms and increasing quality of life in FD patients.

Novel sequential stress model for functional dyspepsia: Efficacy of the herbal preparation STW5

BACKGROUND

Many screening procedures for agents with potential usefulness in functional dyspepsia (FD) rely on animals exposed to stress early in life (neonatal maternal separation, NMS) or in adulthood (restraint stress, RS).

PURPOSE

Since many clinical cases of FD have been associated with stress in early life followed by stress in adulthood, a sequential model simulating the clinical situation is described. To explore the validity of the model, the efficacy of STW5, a multicomponent herbal preparation of proven usefulness in FD, was tested.

STUDY DESIGN/METHODS

A sequential stress model established where rats are exposed to NMS after birth followed later by RS in adulthood. Stress hormones and ghrelin were measured in plasma, while responsiveness of stomach fundus strips to smooth muscle stimulants and relaxants was assessed ex-vivo. The effectiveness of treatment with STW5 a few days before and during exposure to RS in preventing changes induced by the stress model is reported and compared to its efficacy when used in animals subjected to RS alone.

RESULTS

Responses to both stimulants and relaxants were reduced to various extents in the studied models, but treatment with STW5 tended to normalize gastric responsiveness. Plasma levels of ghrelin, corticosterone releasing factor, and corticosterone were raised by RS as well as the sequential model. Treatment with STW5 tended to prevent the deranged parameters.

CONCLUSION

The sequential stress model has a place in drug screening for potential usefulness in FD as it simulates more the clinical setting. Furthermore, the findings shed more light on the mechanisms of action of STW5 in FD.

Isolation and evaluation of the myorelaxant effect of bergapten on isolated rat jejunum

CONTEXT

Plants of the genus Heracleum L. (Apiaceae) have a long history of being used in traditional medicines for the treatment of alimentary tract disorders, and these biological effects have been ascribed to the presence of furanocoumarins (including bergapten).

OBJECTIVES

This study aimed to develop an efficient, preparative, counter-current chromatographic separation of bergapten in order to characterize its spasmolytic activity in isolated rat jejunum strips.

MATERIALS AND METHODS

Successful separation of the dichloromethane extract of the fruits of Heracleum leskovii Grossh. was achieved by high-performance countercurrent chromatography (HPCCC) using a two-phase solvent system composed of n-heptane/EtOAc/MeOH/H2O (6:5:6:5, v/v/v/v). The pharmacological assessment of bergapten (0.0001-50 μM) on jejunum smooth muscle strips isolated from rats was conducted under isotonic conditions, following up to three hours of incubation.

RESULTS

The separation method was scaled up six-fold from analytical to semi-preparative conditions, affording bergapten of >99% purity in less than 30 min. This permitted bergapten to be available in quantity for spasmolytic tests on isolated jejunum strips from rats. Bergapten caused myorelaxation of the intestine preparations in the concentration range of 0.0001-1 μM. At higher doses, bergapten caused either relaxation or contraction of the smooth muscle.

DISCUSSION AND CONCLUSION

Bergapten was successfully isolated by rapid HPCCC and its spasmolytic activity was confirmed, thereby providing a preliminary evidence base for the traditional medicine application. The data suggest that bergapten causes no irreversible changes to intestinal tissue.

Complementary and alternative medicine for gastroparesis

Complementary and alternative medicine is of great interest to patients with gastrointestinal disorders and some will choose to ask their health care providers about those therapies for which some scientific evidence exists. This review focuses on those therapies most commonly used by patients, namely acupuncture/electroacupuncture and various herbal formulations that have been the focus of clinical and laboratory investigation. A discussion of their possible mechanisms of action and the results of clinical studies are summarized.

The use of non-narcotic pain medication in pediatric gastroenterology

The perception of pain in children is easily influenced by environmental factors and psychological comorbidities that are known to play an important role in its origin and response to therapy. Chronic abdominal pain is one of the most commonly treated conditions in modern pediatric gastroenterology and is the hallmark of 'functional' disorders that include irritable bowel syndrome, functional dyspepsia, and functional abdominal pain. The development of pharmacological therapies for these disorders in adults and children has been limited by the lack of understanding of the putative, pathophysiological mechanisms that underlie them. Peripheral and central pain-signaling mechanisms are known to be involved in chronic pain originating from the gastrointestinal tract, but few therapies have been developed to target specific pathways or enhance correction of the underlying pathophysiology. The responses to therapy have been variable, potentially reflecting the heterogeneity of the disorders for which they are used. Only a few small, randomized clinical trials have evaluated the benefit of pain medications for chronic abdominal pain in children and thus, the decision on the most appropriate treatment is often based on adult studies and empirical data. This review discusses the most common, non-narcotic pharmacological treatments for chronic abdominal pain in children and includes a thorough review of the literature to support or refute their use. Because of the dearth of pediatric studies, the focus is on pharmacological and alternative therapies where there is sufficient evidence of benefit in either adults or children with chronic abdominal pain.

Standardized herbal treatments on functional bowel disorders: moving from putative mechanisms of action to controlled clinical trials

Symptom relief in functional gastrointestinal disorders (FGID) is frequently sought with complementary and alternative medicine, and various herbal medicine compounds are popular in different parts of the world. Only a few products, however, are standardized and are backed by scientific evidence. This review mainly focuses on mechanistic and clinical data in support of the Japanese traditional compound Rikkunshi-to (RKT) and of STW-5. Their effects on gut sensori-motor function, neurohormonal network, and controlled clinical data in FGID are revised. RKT and STW-5 appear to possess some degree of gastroprokinetic, visceral analgesic properties, and seem to increase the gastric accommodation response. Controlled trials of RKT and STW-5 support at least a modest effect on symptoms of functional dyspepsia and irritable bowel syndrome, with low side effects profile. With the widespread use of herbals and the relative paucity of effective pharmacological options for FGID, rigorous studies to further elucidate pharmacological actions and clinical applications of herbal compounds are a priority.

Mechanisms of the anti-proliferative and anti-inflammatory effects of the herbal fixed combination STW 5 (Iberogast®) on colon adenocarcinoma (HT29) cells in vitro

INTRODUCTION

Several conventional pharmaceuticals like non-steroidal anti-inflammatory drugs (NSAIDS) or selective cyclooxygenase-2 (COX-2) inhibitors have been demonstrated to exert anti-proliferative effects and to induce apoptosis in a variety of cell lines, e.g. colon, stomach, or prostate cancer cells. STW 5 (Iberogast(®)), a combination of nine plant extracts, is widely used in the treatment of gastrointestinal disorders, including functional dyspepsia and irritable bowel syndrome for which the involvement of an inflammatory etiology is discussed. To investigate the possible anti-proliferative effects, STW 5 and its components have been tested by using the colon-carcinoma cell line HT-29. The analyses have been performed in comparison to acetylsalicylic acid (ASA) and diclofenac (Diclo), which are well-known to reduce colon carcinoma risk.

RESULTS

STW 5 showed significant anti-proliferative and pro-apoptotic effects on HT-29 cancer cells, similar to NSAIDs under test. However, using the LDH assay, STW 5 revealed significantly lower cytotoxicity than Diclo at same concentrations. In contrast to NSAIDs, STW 5 induced COX-1/COX-2, caspase-3 and Bax mRNA expressions in HT-29 and blocked LPS mediated translocation of the NF-κB p65 from the cytoplasm into the nucleus in PMA-differentiated THP-1 macrophages. These effects might be relevant, e.g. for prevention of undesirable side effects like gastric erosions.

CONCLUSION

Our data suggest that the pro-apoptotic effect of STW 5 on HT-29 cells is involving multiple targets and is possibly due to an activation of the caspase cascade via mitochondrial destabilization. Active concentrations of STW 5 are, in relation to therapeutic doses, comparable to those of ASA and Diclo, suggesting a similar favorable effect on colon carcinoma risk.

Chelidonium majus and its effects on uterine contractility in a perfusion model

OBJECTIVE

The herbal agent celandine is thought to have mainly spasmolytic effects, but in the uterus it is regarded as promoting contractions, which can offer promising and innovative options for optimizing artificial reproduction. The aim of the present study was to investigate the effect of celandine on the uterine muscle, using a perfusion model of swine uteri.

STUDY DESIGN

Sixteen swine uteri were perfused with Krebs-Ringer solution. Celandine (Chelidonium, Paverysat; Johannes Bürger Ysatfabrik Ltd., Bad Harzburg, Germany) was administered at increasing dosages. Intrauterine pressure (IUP) was recorded using an intrauterine double-chip microcatheter (Urobar 8 DS-F, Raumedic, Rehau AG & Co., Rehau, Germany). Differences in pressure (ΔP) and area under the curve (ΔAUC) after drug administration in the uterine body and uterine horn in the various dilution series were noted. A paired Student's t-test was used to evaluate differences between groups, with significance set at P<0.05.

RESULTS

A significant initial increase in uterine activity was visible at each dosage. Inhibition of uterine activity was seen over longer periods of 5 and 10 min, particularly for a medium-dose range of 1-2mg/ml. At a dosage of 2mg/ml in particular, celandine almost always led to significant values.

CONCLUSION

Following intra-arterial administration in a swine uterus perfusion model, celandine initially causes a significant increase in contractility, which is followed over time by a relaxation phase. This suggests interesting hypotheses on whether Chelidonium majus might be used to promote targeted sperm transport.

Phytotherapy of chronic abdominal pain following pancreatic carcinoma surgery: a single case observation

A patient with pancreatic carcinoma diagnosed in 2005 suffered from chronic abdominal pain 6 years later that did not respond to conventional pain treatment according to guidelines. Furthermore, several complementary medical approaches remained ineffective. In the long run, only an Iberis amara drug combination relieved pain sufficiently. The drug is registered in Germany for the indications irritable bowel syndrome and dyspepsia. The multi-target approach of this combination drug may account for the effectiveness under these fundamentally different pathophysiological conditions. No serious undesired effects have been described in the use of this drug for other indications and none were observed in this case.

Drug management of visceral pain: concepts from basic research

Visceral pain is experienced by 40% of the population, and 28% of cancer patients suffer from pain arising from intra- abdominal metastasis or from treatment. Neuroanatomy of visceral nociception and neurotransmitters, receptors, and ion channels that modulate visceral pain are qualitatively or quantitatively different from those that modulate somatic and neuropathic pain. Visceral pain should be recognized as distinct pain phenotype. TRPV1, Na 1.8, and ASIC3 ion channels and peripheral kappa opioid receptors are important mediators of visceral pain. Mu agonists, gabapentinoids, and GABAB agonists reduce pain by binding to central receptors and channels. Combinations of analgesics and adjuvants in animal models have supra-additive antinociception and should be considered in clinical trials. This paper will discuss the neuroanatomy, receptors, ion channels, and neurotransmitters important to visceral pain and provide a basic science rationale for analgesic trials and management.

Herbal medicines for the management of irritable bowel syndrome: A comprehensive review

Irritable bowel syndrome (IBS) is a functional gut disorder with high prevalence. Because of various factors involved in its pathophysiology and disappointing results from conventional IBS medications, the treatment of IBS is challenging and use of complementary and alternative medicines especially herbal therapies is increasing. In this paper, electronic databases including PubMed, Scopus, and Cochrane library were searched to obtain any in vitro, in vivo or human studies evaluating single or compound herbal preparations in the management of IBS. One in vitro, 3 in vivo and 23 human studies were included and systematically reviewed. The majority of studies are about essential oil of Menta piperita as a single preparation and STW 5 as a compound preparation. Some evaluated herbs such as Curcuma xanthorriza and Fumaria officinalis did not demonstrate any benefits in IBS. However, it seems there are many other herbal preparations such as those proposed in traditional medicine of different countries that could be studied and investigated for their efficacy in management of IBS.

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

PURPOSE

An herbal preparation, STW 5, used clinically in functional dyspepsia and irritable bowel syndrome, has been shown to possess properties that may render it useful in inflammatory bowel disease (IBD). The present work was conducted to study its effectiveness in a rat model of IBD.

METHODS

An experimental model reflecting ulcerative colitis in man was adopted, whereby colitis was induced in Wistar rats by feeding them 5 % dextran sulfate sodium (DSS) in drinking water for one week. STW 5 and sulfasalazine (as a reference standard) were administered orally daily for 1 week before colitis induction and continued during DSS feeding. The animals were then sacrificed, and the severity of colitis was evaluated macroscopically and microscopically. Colon samples were homogenized for determination of reduced glutathione, tumor necrosis factor-α, and cytokine-induced neutrophil chemoattractant-3 as well as myeloperoxidase, glutathione peroxidase, and superoxide dismutase. In addition, colon segments were suspended in an organ bath to test their reactivity towards carbachol, KCl, and trypsin.

RESULTS

STW 5 and sulfasalazine were both effective in preventing the shortening of colon length and the increase in both colon mass index and total histology score as well as the changes in biochemical parameters measured except changes in dismutase activity. DSS-induced colitis led to marked depression in colonic responsiveness to the agents tested ex vivo, an effect which was normalized by both drugs.

CONCLUSIONS

The findings point to a potential usefulness of STW 5 in the clinical setting of ulcerative colitis.

Adenosine A2A receptor contributes to the anti-inflammatory effect of the fixed herbal combination STW 5 (Iberogast®) in rat small intestinal preparations

STW 5 (Iberogast®), an established herbal combination, was effective in randomized, double blind clinical studies in functional dyspepsia and irritable bowel syndrome. Since STW 5 was found to influence intestinal motility and has anti-inflammatory properties, this study investigated the expression of adenosine receptors and characterized their role in the control of the anti-inflammatory action of STW 5 and its fresh plant component STW 6 in inflammation-disturbed rat small intestinal preparations. The inflammation was induced by intraluminal instillation of 2,4,6-trinitrobenzene sulfonic acid (TNBS, 0.01 M). The effects of coincubation with selective receptor agonists and antagonists, STW 5, STW 6, or combinations of these compounds on acetylcholine (ACh)-evoked contraction of ileum/jejunum preparations were tested. Adenosine receptor mRNA expression was examined by reverse transcription-polymerase chain reaction (RT-PCR). In untreated preparations, RT-PCR revealed the presence of all adenosine receptor subtypes. Suppressed expression was detected for all subtypes in inflamed tissues, except for A(2B)R mRNA, which was unaffected. STW 5 reversed these effects and enhanced A(2A)R expression above control levels. Radioligand binding assays confirm the affinity of STW 5 to the A(2A)R, and the A(2A)R antagonist was able to prevent the effect of STW 5 on TNBS-induced attenuation of the ACh contraction. Our findings provide evidence that STW 5, but not STW 6 interacts with A(2A)R, which is involved in the anti-inflammatory action of STW 5. STW 6 did not contribute to adenosine A(2A)R-mediated anti-inflammatory effect of STW 5. Other signaling pathways could be involved in the mechanism of action of STW 6.

The Size of the Papilla of Vater and Its Relation to Its Height in Comparison with the Visibility of the Sphincter of Oddi before and after Cholecystectomy

This study investigated the changes in the surface area and height of the papilla of Vater (PV) and the visibility of the sphincter of Oddi complex (SOK) using endoscopic ultrasound (EUS) examinations of 80 patients with symptomatic gallstones before and at 3 and 6 months after cholecystectomy. Following surgery, 50 patients experienced early atypical symptoms characteristic of postcholecystectomy syndrome (PCS) and 30 patients were asymptomatic. The PV measurements were greater in all patients compared with normal reference values and increased significantly from before surgery to 3 months postsurgery. At 6 months postsurgery, both the surface area and height of the PV had significantly decreased to preoperative values but remained higher than normal. The proportion of patients with a visible SOK had increased by 3 months postsurgery but had reduced again by 6 months. There were no significant differences between symptomatic and asymptomatic patients, suggesting that the changes observed in the PV and SOK do not explain the presence of the atypical symptoms of PCS.

Effects of the Tibetan herbal formula Padma Lax on visceral nociception and contractility of longitudinal smooth muscle in a rat model

BACKGROUND

The high prevalence of functional bowel disorders among the general population contrasts with the limited number of pharmacological treatment options for this condition. This has led to an interest for alternative therapeutic approaches. Padma Lax is an herbal laxative on the basis of Tibetan formulas. Our aim is to examine the effect of Padma Lax on visceral nociception in vivo and (B) on contractile activity of longitudinal smooth muscle of the lower gut in vitro and ex vivo.

METHODS

(A) Visceral sensory function in response to colorectal distension was assessed by abdominal wall electromyography in male Wistar rats pretreated with Padma Lax. (B) Effects of Padma Lax on contractility of gut smooth muscles were studied both in vitro with superfusion of the agent and ex vivo following oral administration of the preparation. Activities were measured as area under the curve.

KEY RESULTS

(A) For visceral sensitivity, no differences were observed between the Padma Lax and the control group. (B) Proximal colon muscle strips of the Padma Lax pretreated group showed significantly lower spontaneous contractility ex vivo than controls. Cholinergic procontractile stimulation was reduced in Padma Lax pretreated group and in colon strips of naive rats when Padma Lax was superfused in vitro (all P < 0.05).

CONCLUSION & INFERENCES

Cholinergic mechanisms appear to be important in the modulation of rat proximal colon contractility of orally and directly applied Padma Lax. These findings help elucidate a potential mechanism of action of this herbal remedy which has undergone clinical testing in patients with constipation predominant irritable bowel syndrome.

The multi-herbal drug STW 5 (Iberogast) has prosecretory action in the human intestine

There is growing evidence that STW 5 (Iberogast), fixed combination of hydroethanolic herbal extracts), besides being effective in functional dyspepsia, also improves symptoms in irritable bowel syndrome (IBS). Clinical data indicate that modulation of mucosal secretion is a promising approach to treat intestinal disorders associated with IBS. We therefore explored the effect of STW 5 on secretion in the human intestine and the mechanisms by which it acts. The Ussing chamber technique was used to measure mucosal secretion in human intestinal mucosa/submucosa preparations and in human epithelial cell line T84. In addition, we recorded STW 5 effects on human enteric neurons with voltage sensitive dye imaging. In human tissue and T84 cells STW 5 induced a dose-dependent increase in ion secretion that was significantly reduced by the Na-K-Cl cotransporter blocker bumetanide, the adenylate cyclase inhibitor MDL-12 330, the non-specific and selective cystic fibrosis transmembrane conductance regulator (CFTR) inhibitors glibenclamide and CFTR(inh)-172, respectively, and the blocker of calcium dependent Cl(-) channels (ClCa) SITS (4-acetamido-4-isothiocyanatostilbene-2,2-disulphonic acid). It was unaffected by amiloride, a blocker of epithelial Na(+) channels. In human tissue, the nerve blocker tetrodotoxin significantly suppressed the STW 5 response. STW 5 evoked an increased spike discharge in 51% of human submucous neurons. Results suggest that STW 5 is a secretogogue in the human intestine by direct epithelial actions and through activation of enteric neurons. The prosecretory effect is due to increased epithelial Cl(-) fluxes via CFTR and Ca-dependent ClCa channels. STW 5 may be a novel option to treat secretory disorders associated with IBS and constipation.

Inhibition of inflammation-induced alterations in rat small intestine by the herbal preparations STW 5 and STW 6

Inflammation is a common mechanism of many gastrointestinal diseases. Therefore, it is interesting to know, whether complex phytopharmaceuticals known to modulate gastrointestinal motor function reveal also anti-inflammatory properties. We tested the fixed herbal combination product STW 5 (Iberogast((R))) and its main component Iberis amara fresh plant extract (STW 6) to characterize their protective potential in an experimental inflammation model in vitro. The test system consisted of ileum/jejunum segments from male Wistar rats. Inflammation was evoked by intraluminal instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS) for 30min. Preincubation of TNBS together with STW 5 and STW 6 prevented the TNBS-induced inhibition of ACh-induced contractions. No differences were found between water-dissolved and ethanol-dissolved extracts. STW 5 and STW 6 reduced morphological changes induced by TNBS in mucosal and muscle layers. The IL-10 mRNA measured by qRT-PCR was not influenced by TNBS but increased by STW 5 and STW 6. The TNBS-induced increase in the TNFalpha-mRNA expression was suppressed by STW 5 but not by STW 6. Additionally, STW 5 decreased TNFalpha release in LPS-stimulated human monocytes. STW 6 influenced neither the TNFalpha-mRNA nor the TNFalpha release. These findings demonstrate that STW 5 reduced inflammation-induced alterations in ileum/jejunum segments. The effects were associated with a restoration of the disturbed ACh-induced contraction, pathohistological protection and inhibition of TNFalpha. STW 6 may contribute to the protective effect of STW 5 mainly by increasing IL-10 pathway but not by influencing TNFalpha.

STW 5/Iberogast: Multi-Target-Wirkung bei funktioneller Dyspepsie und Reizdarmsyndrom

Functional gastro-intestinal diseases such as functional dyspepsia and irritable bowel syndrome are a therapeutic challenge, as they are not only characterized by a multitude of symptoms, some of them with severe consequences for affected patients, but are also caused by a multitude of factors. The clinical efficacy of the therapeutics STW 5/Iberogast in these diseases has been proven in a number of randomized prospective clinical studies. Several preclinical studies suggest that its efficacy could be due to its complex composition of nine standardized herbal extracts, which act differently on multiple sites. This principle, which is quite popular in clinical medicine, was introduced as a multi-target therapy for functional bowel disorders. Components of STW 5/Iberogast reduce gastro-intestinal hypersensitivity and act spasmolytic on spastic, tonicising on atonic gastro-intestinal muscle. In addition a stimulating effect on reduced mucus-secretion, an inhibitory effect on enhanced gastric acid secretion and an anti-inflammatory effect have been shown. These effects could explain the clinical efficacy of STW5/Iberogast in a large range of symptoms.

STW 5 (Iberogast) reduces afferent sensitivity in the rat small intestine

INTRODUCTION

A limited number of drugs are available for the treatment of functional dyspepsia and irritable bowel syndrome. The efficacy of STW 5 (Iberogast) was previously shown in clinical trials. Since visceral hypersensitivity seems to be the prime pathomechanism of functional gastro-intestinal disorders, the aim of this study was to explore whether STW 5 reduces intestinal afferent sensitivity in the upper gastrointestinal tract.

METHODS

Two groups of male Wistar rats were pretreated with either the herbal preparation STW 5 or its vehicle (30.8% ethanol). Then, after 2h, general anesthesia was induced by pentobarbitone (60 mg kg(-1)i.p.) and extracellular multi-unit afferent recordings were obtained from mesenteric afferents innervating the proximal jejunum. The intestinal afferent nerve response to increasing doses of 5-HT and bradykinin were quantified as well as afferent discharge following a ramp distension of the adjacent intestinal loop from 0 to 60 cm H(2)O.

RESULTS

Afferent discharge to 5-HT and bradykinin increased dose-dependently. Following the different doses of 5-HT, the peak in afferent nerve discharge was always reduced after pretreatment with STW 5 compared to controls with a response of 110+/-5 imp s(-1) after STW 5 and 128+/-3 in vehicle controls at the maximum dose (40 microg kg(-1); p<0.05; mean+/-SEM). For bradykinin, afferent responses were reduced following STW 5 at the 20 and 40 microg kg(-1) dose but not at 10 microg kg(-1) (40 microg kg(-1)176+/-7 imp s(-1) following STW 5 versus 200+/-6 imp s(-1) in controls; p<0.05). The ramp distension of the intestinal loop stimulated a rise in intestinal afferent nerve discharge that was always lower in the STW 5 pretreated group compared to vehicle controls with the exception of the discharge rate at the pressure level of 0 and 20 cm H(2)O (all other pressures up to 60 cm H(2)O p<0.05).

CONCLUSIONS

Sensitivity of intestinal afferents to mechanical and chemical stimuli is reduced following treatment with the herbal preparation STW 5. This mechanism may help to explain why STW 5 relieves dyspeptic and bowel symptoms in patients.

The active components and the pharmacological multi-target principle of STW 5 (Iberogast)

The therapeutic equivalence of the multi-herbal drug combination STW 5 (Iberogast) with two synthetic standard drugs can be explained by an additive or overadditive pharmacological synergism. A review of the different chemical constituents contained in this fixed combination of nine herbal drug extracts and their dominant mechanisms of action shows that they correlate very well with the clinically relevant overall pharmacological profile of the multi-herbal drug combination. This comprises modulatory effects on gastro-intestinal motility, anti-inflammatory action, inhibitory effects on gastric acid production and anti-oxidative and radical-inhibiting properties. As a multi-drug preparation with a multitude of therapeutic targets relevant in functional gastrointestinal diseases, its pharmacological profile of action in accordance with the multi-target principle.

Binding of STW 5 (Iberogast) and its components to intestinal 5-HT, muscarinic M3, and opioid receptors

Clinical studies with the fixed herbal combination product STW 5 (Iberogast) have indicated an efficacy comparable to metoclopramide (5-HT(3) antagonist) and cisapride (5-HT(4) agonist) in functional gastro-intestinal diseases like functional dyspepsia (FD) and irritable bowel syndrome (IBS). Since serotonin (5-HT(3) and 5-HT(4)) and muscarinic M(3) receptors are known to play a central role in the etiology of FD and IBS, the extracts contained in STW 5 and several of their phytochemical components were studied in vitro for binding affinities to these receptors of the intestine. STW 5 inhibited the binding of (3)H-GR113808 and (3)H-4-DAMP to 5-HT(4) and M(3) receptors, respectively, about 10 times more potently than the binding of (3)H-GR65630 to 5-HT(3) receptors. IC(50) values for STW 5 did correspond to extract dilutions of 1:1000 (M(3) binding) and 1:2000 (5-HT(4) binding). In addition, STW 5 also potently inhibited the binding to opioid receptors with an IC(50) value of 1:2000. Of the nine herbal extracts contained in STW 5, the fresh plant extract of bitter candy tuft (Iberis amara) selectively inhibited binding to M(3) receptors, while ethanolic extracts of celandine herb and chamomile flower were selective to 5-HT(4), and liquorice root to 5-HT(3) receptors. Binding affinities to human recombinant 5-HT(3), 5-HT(4) and M(3) receptors were qualitatively similar to those of the corresponding intestinal receptors. The benzylisoquinoline alkaloid berberine had significant inhibitory action on 5-HT(4) and M(3) binding, showing IC(50) values of 40 ng/ml (100 nM) and 200 ng/ml (500 nM), respectively, but is present in the extract of celandine herb only in traces, so that also for the celandine extract a cooperative effect of several phytochemical constituents can be assumed. These in vitro data indicate that 5-HT(4) (to a lesser degree 5-HT(3)), muscarinic M(3), and opioid receptors represent target sites for the treatment of FD and IBS with STW 5 (Iberogast).

Intestinal spasmolytic effects of STW 5 (Iberogast) and its components

Functional gastro-intestinal diseases as the irritable bowel syndrome are very common in the population and are characterized by a broad spectrum of symptoms which mostly are related to spastic or paralytic intestinal function without defined histopathological changes of the tissue. Due to the multifactorial pathogenesis a multifactorial therapy with multi-target action seems to be reasonable. STW 5 (Iberogast), its constituent herbal extracts and some isolated compounds were used in an in vitro model provided by intestinal samples from guinea pig in order to test their activity on histamine-induced contractions and spontaneous motility, respectively. For comparison the known spasmolyticum papaverine was used. The results show that the lytic effect of the phytotherapeuticum on histamine-induced contraction represents additively the actions of the different components and corresponds to approx. 10 microM of papaverine. Spontaneous peristaltic motion was differently modulated by the various constituent extracts. The experiments with silibinin, glycyrrhicine, chelidonine, and protopine showed that the effects of the extracts were not comparable to those of the respective chemical constituents.