Effect of hyoscine butylbromide (Buscopan®) on cholinergic pathways in the human intestine

E. coli infection disrupts the epithelial barrier and activates intrinsic neurosecretory reflexes in the pig colon

This study aims to assess the barrier integrity and possible activation of enteric neural pathways associated with secretion and motility in the pig colon induced by an enterotoxigenic Escherichia coli (ETEC) challenge. 50 Danbred male piglets were used for this study. 16 were challenged with an oral dose of the ETEC strain F4+ 1.5 × 10⁹ colony-forming unit. Colonic samples were studied 4- and 9-days post-challenge using both a muscle bath and Ussing chamber. Colonic mast cells were stained with methylene blue. In control animals, electrical field stimulation induced neurosecretory responses that were abolished by tetrodotoxin (10^-6M) and reduced by the combination of atropine (10^-4M) and α-chymotrypsin (10U/mL). Exogenous addition of carbachol, vasoactive intestinal peptide, forskolin, 5-HT, nicotine, and histamine produced epithelial Cl^- secretion. At day 4 post-challenge, ETEC increased the colonic permeability. The basal electrogenic ion transport remained increased until day 9 post-challenge and was decreased by tetrodotoxin (10^-6M), atropine (10^-4M), hexamethonium (10^-5M), and ondansetron (10^-5M). In the muscle, electrical field stimulation produced frequency-dependent contractile responses that were abolished with tetrodotoxin (10^-6M) and atropine (10^-6M). Electrical field stimulation and carbachol responses were not altered in ETEC animals in comparison with control animals at day 9 post-challenge. An increase in mast cells, stained with methylene blue, was observed in the mucosa and submucosa but not in the muscle layer of ETEC-infected animals on day 9 post-challenge. ETEC increased the response of intrinsic secretory reflexes and produced an impairment of the colonic barrier that was restored on day 9 post-challenge but did not modify neuromuscular function.

The effects of the use of hyoscine-N-butylbromide during laparoscopic sleeve gastrectomy

Objectives

Hyoscine-N-butylbromide is used by some surgeons during laparoscopic sleeve gastrectomy (LSG) to loosen gastric smooth muscles and to provide a more effective LSG. However, evidence-based data on the effects of hyoscine-N-butylbromide in laparoscopic sleeve gastrectomy are limited and its effect on sleeve gastrectomy surgery and weight loss is unknown. The aim of this study was to analyze the effect of intraoperatively administered hyoscine-N-butylbromide on stomach resection volume, weight loss and complications seen in patients undergoing LSG.

Material and Methods

Patients who underwent laparoscopic sleeve gastrectomy due to morbid obesity were included in the study. Intraoperative hyoscine-N-butylbromide was administered to 52 patients (Group 1), not applied to the other 52 patients (Group 2). Age, sex, height, weight and body mass index (BMI) data of the patients were obtained retrospectively. The weight, BMI, percentage of total weight loss (TWL%) and percentage of excess weight loss (EWL%) of the patients were evaluated at postoperative third, sixth and 12th months.

Results

Resected gastric volume (p= 0.111), length of stapler line (p= 0.944), operation time (p= 0.383), hospitalization time (p= 0.494) and postoperative complications (p> 0.05) did not differ between Groups 1 and 2. However, frequency of intraoperative tachycardia (p <0.001) and hypotension (p= 0.006) in Group 1 was significantly higher than in Group 2. TWL% and EWL% values were similar between the two groups at all-time points. Stapler line leakage was not observed in any patient during the postoperative period.

Conclusion

Intraoperative hyoscine-N-butylbromide use is not effective on weight loss postoperatively in patients undergoing LSG. Although hypotension and tachycardia occured in some of patients, none of the patients had complaints in the early or long-term postoperative period. The use of hyoscine-N-butylbromide during LSG is safe but does not have any effect on weight loss.

Hyoscine butylbromide mode of action on bowel motility: From pharmacology to clinical practice

BACKGROUND

Hyoscine butylbromide (HBB) has been available for use as an antispasmodic since 1951 and is indicated for the treatment of abdominal pain associated with cramps. A previous review in 2007 summarized the evidence on the mode of action of HBB in vitro and in vivo in both animal and human studies. However, since then, novel publications have appeared within the literature and also our knowledge of what represents normal motility in humans has evolved.

PURPOSE

This review is the result of the collaboration between a basic scientist and clinicians with the aim of providing an updated overview of the mechanisms of action of HBB and its clinical efficacy to guide not only use in clinical practice, but also future research.

Silver Nanoparticles Application as a Colorimetric Probe for the Spectrophotometric Determination of Hyoscine Butylbromide in Pharmaceutical Formulations

BACKGROUND

Hyoscine butylbromide is used as an antispasmodic in treating peptic ulcers, gastritis, and various disorders of the gastrointestinal tract that are characterized by spasms. It has also found employment for the relief of spasmodic conditions of the bile duct and urinary tract and for the treatment of dysmenorrhea.

OBJECTIVE

In this study, the application of silver nanoparticles (Ag NPs) as a colorimetric probe for the fast, selective, and simple determination of hyoscine butylbromide was described.

METHODS

The proposed method was based on the Ag NPs aggregation induced by their interaction with the cited drug. This interaction produced a color change from yellow to colorless measured at 405 nm.

RESULTS

The method linear concentration range was 0.10-50.0 µg/mL with a correlation equation (y = 0.0132 x + 0.3174), correlation coefficient of 0.9981, and quantification limits of 0.091 µg/mL. A thorough investigation was done to validate the method's analytical performance, and the findings were satisfactory. With great accuracy and precision, this approach was used to identify the medication in pharmaceutical tablet samples with recovery percentages ranging from 96.20 to 98.10%.

CONCLUSIONS

Since there are no critical reaction conditions or solvent extraction involved in the described method, it is distinguished by its simplicity. The results were quite consistent with those attained using the approved standard method.

HIGHLIGHTS

Simple, fast, and sensitive colorimetric probe developed for determination of hyoscine butylbromide in pharmaceutical formulations.

Atropine-functionalized gold nanoparticles binding to muscarinic receptors after passage across the intestinal epithelium

Gold nanoparticles have a high potential to be a treatment of diseases by their specific drug delivery properties and multivalent receptor stimulation. For the present project, spherical gold nanoparticles were synthesized and functionalized with the muscarinic receptor antagonist atropine (Au-MUDA-AT NPs). The diameter of the gold core could precisely be controlled by using different synthetic methods and reducing agents resulting in functionalized gold nanoparticles with diameters ranging from 8 to 16 nm. The ability to interact with intestinal muscarinic receptors is size-dependent. When using intestinal chloride secretion induced by the stable acetylcholine derivative, carbachol, as read-out, the strongest inhibition, i.e. the most efficient blockade of muscarinic receptors, was observed with 13 nm sized Au-MUDA-AT NPs. Functional experiments indicate that Au-MUDA-AT NPs with a diameter of 14 nm are able to pass the intestinal mucosa in a time-dependent manner after administration to the intestinal lumen. For example, luminally administered Au-MUDA-AT NPs inhibited contractions of the small intestinal longitudinal muscle layer induced by electrical stimulation of myenteric neurons. A similar inhibition of basolateral epithelial receptors was observed after luminal administration of Au-MUDA-AT NPs when using carbachol-induced chloride secretion across the intestinal epithelium as a test system. Thus, Au-MUDA-AT NPs might be a therapeutic tool for the modulation of intestinal secretion and motility after oral application in the future.

High-Yield 99mTc Labeling of Gold Nanoparticles Carrying Atropine and Adrenaline

This work focuses on the synthesis, purification, and analytical characterization of novel multifunctional Au NPs radiolabeled with ^99mTc. These mixed-ligand shell Au NPs represent pharmacologically relevant samples for potential application in theragnostics. A ligand using a plain linker with a rather long chain consisting of 10 CH₂ groups and a thiol moiety along with the PADA chelator has been used for both the attachment to the Au NP surface and for the ^99mTc(CO)₃⁺ complexation. We have combined this with our approach of stabilizing Au NP without any PEG or other stabilizing groups. Thus, monoligand shell Au NPs were radiolabeled by different strategies (prelabeling and postlabeling). Additionally, pharmacologically relevant Au NPs were synthesized carrying both a biofunctionalization with either atropine or adrenaline and the ^99mTc radiolabel. All samples were obtained in very good yields (up to 80% of the total activity loaded onto the column) and completely/particularly purified using desalting columns. Detailed analytical characterization of the Au NPs before and after radiolabeling has proven the NPs' robustness throughout the process. Their intact functionalization, shape, and stability was confirmed by transmission electron microscopy (TEM), ultraviolet/visible (UV/vis) spectroscopy, dynamic light scattering (DLS), and infrared (IR) spectroscopy. The presented strategy represents a versatile building block system that can be adapted to a variety of bioactive molecules and may be of high relevance for theragnostic applications.

L-Menthol for Gastrointestinal Endoscopy: A Systematic Review and Meta-Analysis

In randomized controlled trials, L-menthol inhibits gastrointestinal peristalsis during endoscopy. Our goal was to quantitatively synthesize the available evidence to evaluate the efficacy and safety of L-menthol for gastrointestinal endoscopy.

Effective bowel motion reduction in mouse abdominal MRI using hyoscine butylbromide

PURPOSE

Bowel motion is a significant source of artifacts in mouse abdominal MRI. Fasting and administration of hyoscine butylbromide (BUSC) have been proposed for bowel motion reduction but with inconsistent results and limited efficacy assessments. Here, we evaluate these regimes for mouse abdominal MRI at high field.

METHODS

Thirty-two adult C57BL/6J mice were imaged on a 9.4T scanner with a FLASH sequence, acquired over 90 min with ~19 s temporal resolution. During MRI acquisition, 8 mice were injected with a low-dose and 8 mice with a high-dose bolus of BUSC (0.5 and 5 mg/kg, respectively). Eight mice were food deprived for 4.5-6.5 hours before MRI and another group of eight mice was injected with saline during MRI acquisition. Two expert readers reviewed the images and classified bowel motion, and quantitative voxel-wise analyses were performed for identification of moving regions. After defining the most effective protocol, high-resolution T₂ -weighted and diffusion-weighted images were acquired from 4 mice.

RESULTS

High-dose BUSC was the most effective protocol for bowel motion reduction, for up to 45 min. Fasting and saline protocols were not effective in suppressing bowel motion. High-resolution abdominal MRI clearly demonstrated improved image quality and ADC quantification with the high-dose BUSC protocol.

CONCLUSION

Our data show that BUSC administration is advantageous for abdominal MRI in the mouse. Specifically, it endows significant bowel motion reduction, with relatively short onset timings after injection (~8.5 min) and relatively long duration of the effect (~45 min). These features improve the quality of high-resolution images of the mouse abdomen.

Irritable Bowel Syndrome: News from an Old Disorder

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder, which can affect all members of a society, regardless of age, sex, race or socioeconomic status. Because of its high prevalence and chronic nature, it represents a significant economic burden. In fact, these patients have a relevant impairment of their quality of life, which limits their work productivity and daily social activities, especially when it is associated with other disorders, such as anxiety and depression. The diagnosis of IBS relies on symptom-based diagnostic criteria with normal results on a limited number of complementary tests that rule out other possible diagnoses. The aetiology of this condition is incompletely established. However, evidence suggests that it is a multifactorial disorder with several different mechanisms that have been implicated as responsible for the symptoms. Since the treatment strategy is usually based on predominant symptoms and their severity, it is important to recognise the underlying mechanisms in order to successfully relief the visceral pain and altered bowel habits. The aim of this non-systematic review of the literature was to explore the pathophysiology and treatment options of IBS, highlighting the most recent evidence, from the new Rome IV criteria to the new drug armamentarium.

Peppermint and caraway oils have muscle inhibitory and pro-secretory activity in the human intestine in vitro

BACKGROUND

Herbal medicinal products with a broad activity spectrum may be promising alternatives to treat functional gastrointestinal disorders (FGD). Menthacarin^® is a drug with a fixed combination of peppermint and caraway oils, which is clinically used to treat FGD-associated symptoms.

MATERIALS

We studied the effects of peppermint and caraway oils on contractile and secretory activity in 255 human small and large intestinal preparations derived from surgical resections (73 patients). Motility was recorded in circular smooth muscle strips and secretion with the Ussing chamber-voltage clamp technique. Electrical field stimulation evoked nerve induced contractile responses. KEY RESULTS: Peppermint and caraway oil concentrations dependently inhibited muscle contractility as indicated by sustained muscle relaxation and decrease in phasic contractility. These effects occurred in small and large intestinal preparations with IC₅₀ values ranging between 17 and 90 µg/mL for peppermint oil and between 7 and 127 µg/mL for caraway oil. Neither peppermint nor caraway oil influenced the nerve evoked contractile response. The inhibition of contractile activity, but not the muscle relaxation, was prevented by the L-type calcium channel activator Bay K8644 but not by the neurotoxin tetrodotoxin. Both peppermint oil and caraway oil increased epithelial secretion, which remained in tetrodotoxin.

CONCLUSION & INTERFERENCE

The findings revealed a strong muscle inhibitory and pro-secretory action of peppermint and caraway oils at clinically relevant concentrations. Both actions were nerve-independent. The inhibition of contractility was mediated by inhibition of L-type calcium channels. The effects on muscle and epithelial activity may contribute to the beneficial effects observed in patients with FGD.

bis-(p-hydroxyphenyl)-pyridyl-2-methane (BHPM)-the active metabolite of the laxatives bisacodyl and sodium picosulfate-enhances contractility and secretion in human intestine in vitro

BACKGROUND

Stimulant laxatives are widely used to treat constipation. We investigated in human small and large intestinal preparations the effects of bis-(p-hydroxyphenyl)-pyridyl-2-methane (BHPM), the active metabolite of the laxatives bisacodyl and sodium picosulfate on smooth muscle tone and epithelial secretion.

METHODS

Circular and longitudinal muscle tone of small or large intestinal preparations were recorded with isometric force transducers. Epithelial ion flux (I_SC ) and tissue resistance was measured with Ussing chamber technique after apical and basolateral BHPM application to large intestinal mucosa/submucosa preparations. Studies were performed in macroscopically normal specimens from 79 patients.

KEY RESULTS

BHPM concentration-dependently (0.5-5 μM) increased the tone of circular and longitudinal muscle from small to large intestine. The effect was strongest in large intestinal longitudinal muscle and smallest in small intestinal circular muscle. Increase in muscle tone was prevented by the L-type Ca⁺⁺ channel blocker nifedipine but insensitive to the nerve blocker tetrodotoxin. Apical or basolateral BHPM concentration-dependently decreased or increased I_SC, respectively. The K_Ca 1.1 (BK) channel blocker iberiotoxin reversed apical I_SC decrease whereas tetrodotoxin reversed basolateral I_SC increase. BHPM had no effect on tissue resistance or nerve-mediated secretory or muscle response with one exception: at the highest concentration basolateral BHPM reduced nerve-mediated secretion.

CONCLUSIONS AND INTERFERENCES

BHPM enhanced mucosal secretion and muscle contractility. Results suggested that the laxative effect of BHPM was a consequence of the increase in muscle tone as well as an increased K⁺ secretion when acting luminally and a nerve-driven Cl^- and HCO₃^- secretion once acting basolaterally after absorption.

Medications influencing central cholinergic neurotransmission affect saccadic and smooth pursuit eye movements in healthy young adults

RATIONALE

Acetylcholine is an important neuromodulator in the central nervous system, where it plays a significant role in central functions such as the regulation of movement.

OBJECTIVE

This study investigated the pharmacological effects of over-the-counter anticholinergic medications on saccadic and smooth pursuit eye movements, in order to establish the significance of central cholinergic pathways in the control of these centrally regulated oculomotor processes.

METHODS

Sixteen subjects (mean age 23 ± 3 years, 9 females) performed pro-saccadic, anti-saccadic and smooth pursuit eye movement tests, while an eye tracker collected eye movement data. Oculomotor assessments were performed pre-ingestion, 0.5 and 2 h post-ingestion of drugs with varying degrees of central anticholinergic properties. The drugs tested were promethazine, hyoscine hydrobromide, hyoscine butylbromide and placebo.

RESULTS

The drug intervention with stronger central anticholinergic properties, promethazine, decreased amplitude and increased velocity in the pro-saccadic task and increased duration in the anti-saccadic task. Promethazine, once again, was the only drug to decrease eye velocity in the smooth pursuit test.

CONCLUSION

The prominent effects of the stronger central anticholinergic promethazine, on saccadic and smooth pursuit eye movements, potentially conveys the significance of central cholinergic pathways in the control of these centrally regulated oculomotor processes.

Anticholinergic activity in the nervous system: Consequences for visuomotor function

Acetylcholine is present in the peripheral and central nervous system, where it is involved in a number of fundamental physiological and biochemical processes. In particular, interaction with muscarinic receptors can cause adverse effects such as dry mouth, drowsiness, mydriasis and cognitive dysfunction. Despite the knowledge that exists regarding these common side-effects, little is known about how anticholinergic medications influence central motor processes and fine motor control in healthy individuals. This paper reviews critical visuomotor processes that operate in healthy individuals, and how controlling these motor processes are influenced by medications that interfere with central cholinergic neurotransmission. An overview of receptor function and neurotransmitter interaction following the ingestion or administration of anticholinergics is provided, before exploring how visuomotor performance is affected by anticholinergic medications. In particular, this review will focus on the effects that anticholinergic medications have on fixation stability, saccadic eye movements, smooth pursuit eye movements, and general pupil dynamics.

Irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disease with a high population prevalence. The disorder can be debilitating in some patients, whereas others may have mild or moderate symptoms. The most important single risk factors are female sex, younger age and preceding gastrointestinal infections. Clinical symptoms of IBS include abdominal pain or discomfort, stool irregularities and bloating, as well as other somatic, visceral and psychiatric comorbidities. Currently, the diagnosis of IBS is based on symptoms and the exclusion of other organic diseases, and therapy includes drug treatment of the predominant symptoms, nutrition and psychotherapy. Although the underlying pathogenesis is far from understood, aetiological factors include increased epithelial hyperpermeability, dysbiosis, inflammation, visceral hypersensitivity, epigenetics and genetics, and altered brain-gut interactions. IBS considerably affects quality of life and imposes a profound burden on patients, physicians and the health-care system. The past decade has seen remarkable progress in our understanding of functional bowel disorders such as IBS that will be summarized in this Primer.

Pharmacological, Pharmacokinetic, and Pharmacogenomic Aspects of Functional Gastrointestinal Disorders

This article reviews medications commonly used for the treatment of patients with functional gastrointestinal disorders. Specifically, we review the animal models that have been validated for the study of drug effects on sensation and motility; the preclinical pharmacology, pharmacokinetics, and toxicology usually required for introduction of new drugs; the biomarkers that are validated for studies of sensation and motility endpoints with experimental medications in humans; the pharmacogenomics applied to these medications and their relevance to the FGIDs; and the pharmacology of agents that are applied or have potential for the treatment of FGIDs, including psychopharmacologic drugs.

Suspected levamisole intoxication in calves

CASE HISTORY

A group of 32 Friesian and four Hereford calves, 3-4 months old with body weights between 100-120 kg, were purchased from a weaner sale. On arrival at the property the Hereford calves were treated with a combination anthelmintic containing 2 g/L abamectin and 80 g/L levamisole hydrochloride. Shortly afterwards they developed tremors and frothing from the mouth, and two died overnight. The Friesian calves were treated with the same anthelmintic on the following day, when some showed hypersalivation and frothing from the mouth.

CLINICAL FINDINGS

Examination of the three most severely affected Friesian calves revealed severe nicotinic-type symptoms including hypersalivation, frothing from the mouth, muscle tremors, recumbency, rapid respiration, hyperaesthesia, and central nervous system depression. Other calves showed mild to moderate signs of intoxication including restlessness, tail switching, salivation, tremors, frequent defaecation, mild colic and jaw chomping. Two calves died shortly afterwards. An adverse drug event investigation revealed that the formulation and quality of the anthelmintic was within the correct specification, and that the drench gun was functioning correctly.

DIAGNOSIS

Suspected levamisole intoxication due to a combination of possible overdosing, dehydration, and stress caused by transportation and prolonged yarding.

CLINICAL RELEVANCE

Susceptibility to levamisole toxicity in New Zealand calves can be increased if factors like dehydration or stress are present. Levamisole has a narrow margin of safety, and overdosing in calves can easily occur if the dose rate is not based on their actual weight or health status.

Neural influences on human intestinal epithelium in vitro

KEY POINTS

We present the first systematic and, up to now, most comprehensive evaluation of the basic features of epithelial functions, such as basal and nerve-evoked secretion, as well as tissue resistance, in over 2200 surgical specimens of human small and large intestine. We found no evidence for impaired nerve-evoked epithelial secretion or tissue resistance with age or disease pathologies (stomach, pancreas or colon cancer, polyps, diverticulitis, stoma reversal). This indicates the validity of future studies on epithelial secretion or resistance that are based on data from a variety of surgical specimens. ACh mainly mediated nerve-evoked and basal secretion in the small intestine, whereas vasoactive intestinal peptide and nitric oxide were the primary pro-secretory transmitters in the large intestine. The results of the present study revealed novel insights into regional differences in nerve-mediated secretion in the human intestine and comprise the basis by which to more specifically target impaired epithelial functions in the diseased gut.

ABSTRACT

Knowledge on basic features of epithelial functions in the human intestine is scarce. We used Ussing chamber techniques to record basal tissue resistance (R-basal) and short circuit currents (ISC; secretion) under basal conditions (ISC-basal) and after electrical field stimulation (ISC-EFS) of nerves in 2221 resectates from 435 patients. ISC-EFS was TTX-sensitive and of comparable magnitude in the small and large intestine. ISC-EFS or R-basal were not influenced by the patients' age, sex or disease pathologies (cancer, polyps, diverticulitis). Ion substitution, bumetanide or adenylate cyclase inhibition studies suggested that ISC-EFS depended on epithelial cAMP-driven chloride and bicarbonate secretion but not on amiloride-sensitive sodium absorption. Although atropine-sensitive cholinergic components prevailed for ISC-EFS of the duodenum, jejunum and ileum, PG97-269-sensitive [vasoactive intestinal peptide (VIP) receptor 1 antagonist] VIPergic together with L-NAME-sensitive nitrergic components dominated the ISC-EFS in colonic preparations. Differences in numbers of cholinergic or VIPergic neurons, sensitivity of epithelial muscarinic or VIP receptors, or stimulus frequency-dependent transmitter release were not responsible for the region-specific transmitter contribution to ISC-EFS. Instead, the low atropine-sensitivity of ISC-EFS in the colon was the result of high cholinesterase activity because neostigmine revealed cholinergic components. Colonic ISC-EFS remained unchanged after tachykinin, P2X, P2Y or A1 and A2 receptor blockade. R-basal was smaller and ISC-basal was higher in the small intestine. TTX and bumetanide decreased ISC-basal in all regions, suggesting nerve-dependent secretory tone. ISC-basal was atropine-sensitive in the small intestine and PG97-269-sensitive in the large intestine. This comprehensive study reveals novel insights into region-specific nerve-mediated secretion in the human small and large intestine.

Extracts from peppermint leaves, lemon balm leaves and in particular angelica roots mimic the pro-secretory action of the herbal preparation STW 5 in the human intestine

AIM

The herbal preparation STW 5 contains fresh plant extracts from bitter candytuft whole plant, extracts from greater celandine herb, angelica root, lemon balm leaves, peppermint leaves, caraway fruit, liquorice root, chamomile flower and milk thistle fruit. We recently reported that STW 5 increased intestinal chloride secretion and proposed that this action may be involved in its clinical efficacy in the treatment of irritable bowel syndrome. The aim of this study was to identify the extracts responsible for the secretory action in order to provide the basis to develop novel target oriented herbal combinations.

METHODS

We used the Ussing chamber voltage clamp technique to study the effects of individual extracts of STW 5 on short circuit current (Isc, reflecting electrogenic ion transport across epithelial cells) in mucosal/submucosal preparations of human small or large intestinal specimens and the human epithelial cell line T84.

RESULTS

STW 5 at concentrations of 512 µg/ml and 5120 µg/ml evoked an increase in Isc. The increase at the lower concentration was due to pro-secretory effects of angelica which were nerve mediated. The increase at the higher concentration was additionally mimicked by peppermint and lemon balm. The remaining extracts did not influence ISC in the large intestine. The results were similar in T84 cells except that angelica had no effect while chamomile induced secretion. These pro-secretory effects were reduced by adenylate cyclase inhibitor MDL-12330A, cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor CFTRinh-172 and calcium activated chloride channels blocker 4-acetamido-4-isothiocyanatostilbene-2,2-disulphonic acid (SITS). Liquorice decreased ISC only in small intestine which was reversed by the epithelial sodium channel blocker amiloride.

CONCLUSIONS

Results suggested that the pro-secretory action of STW 5 is mainly due to angelica with lesser contribution of peppermint and lemon balm. Their effects involve activation of cAMP- and Ca(++)-activated Cl(-) channels. We suggest that peppermint, lemon balm and in particular angelica may be the basis to develop novel herbal preparations to specifically treat secretory disorder based on impaired epithelial secretion, such as constipation.

New technologies and techniques to improve adenoma detection in colonoscopy

Adenoma detection rate (ADR) is a key component of colonoscopy quality assessment, with a direct link between itself and future mortality from colorectal cancer. There are a number of potential factors, both modifiable and non-modifiable that can impact upon ADR. As methods, understanding and technologies advance, so should our ability to improve ADRs, and thus, reduce colorectal cancer mortality. This article will review new technologies and techniques that improve ADR, both in terms of the endoscopes themselves and adjuncts to current systems. In particular it focuses on effective techniques and behaviours, developments in image enhancement, advancement in endoscope design and developments in accessories that may improve ADR. It also highlights the key role that continued medical education plays in improving the quality of colonoscopy and thus ADR. The review aims to present a balanced summary of the evidence currently available and does not propose to serve as a guideline.

Evidence for neuronal and structural changes in submucous ganglia of patients with functional dyspepsia

OBJECTIVES

An intact and well-functioning enteric nervous system is necessary to efficiently organize gut function. Functional gastrointestinal disorders are pathological entities in which gut function is impaired without a clearly established pathophysiology. On the basis of the relative ease with which intestinal biopsies can be obtained, and taking advantage of a recently developed optical recording technique, we evaluated whether functional neuronal defects exist in enteric nerves of patients with functional dyspepsia (FD).

METHODS

The submucous plexus isolated from duodenal biopsies taken from FD patients and control subjects was used to functionally and morphologically examine nerves and ganglionic architecture (neurons and glial cells). In light of previous studies reporting eosinophil and mast cell infiltration in the gut mucosa of FD patients, we also examined whether these cells infiltrated the submucous plexus and whether this correlated with neuronal activity and specific clinical symptoms.

RESULTS

We demonstrate that neuronal functioning is impaired in the submucous plexus of FD patients, as shown by decreased calcium responses to depolarization and electrical stimulation. Glial (S100) and neuronal (HuCD) markers show signs of gliosis, altered ganglionic architecture, and neuronal abnormalities in the submucous plexus of FD patients. We found that eosinophils and mast cells infiltrated the submucous layer of FD patients to a much larger extent than in controls. A significant correlation was found between the number of these cells and the calcium transient amplitudes measured in submucous ganglia.

CONCLUSIONS

We provide the first direct evidence that FD is characterized by functional and structural abnormalities within the submucous ganglion plexus, which may be of future predictive and diagnostic value in the treatment of FD patients.

Inhibiting endocannabinoid biosynthesis: a novel approach to the treatment of constipation

BACKGROUND AND PURPOSE

Endocannabinoids are a family of lipid mediators involved in the regulation of gastrointestinal (GI) motility. The expression, localization and function of their biosynthetic enzymes in the GI tract are not well understood. Here, we examined the expression, localization and function of the enzyme diacylglycerol lipase-α (DAGLα), which is involved in biosynthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG).

EXPERIMENTAL APPROACH

Cannabinoid CB1 receptor-deficient, wild-type control and C3H/HeJ mice, a genetically constipated strain, were used. The distribution of DAGLα in the enteric nervous system was examined by immunohistochemistry. Effects of the DAGL inhibitors, orlistat and OMDM-188 on pharmacologically induced GI hypomotility were assessed by measuring intestinal contractility in vitro and whole gut transit or faecal output in vivo. Endocannabinoid levels were measured by mass spectrometry.

KEY RESULTS

DAGLα was expressed throughout the GI tract. In the intestine, unlike DAGLβ, DAGLα immunoreactivity was prominently expressed in the enteric nervous system. In the myenteric plexus, it was colocalized with the vesicular acetylcholine transporter in cholinergic nerves. In normal mice, inhibiting DAGL reversed both pharmacologically reduced intestinal contractility and pharmacologically prolonged whole gut transit. Moreover, inhibiting DAGL normalized faecal output in constipated C3H/HeJ mice. In colons incubated with scopolamine, 2-AG was elevated while inhibiting DAGL normalized 2-AG levels.

CONCLUSIONS AND IMPLICATIONS

DAGLα was expressed in the enteric nervous system of mice and its inhibition reversed slowed GI motility, intestinal contractility and constipation through 2-AG and CB1 receptor-mediated mechanisms. Our data suggest that DAGLα inhibitors may be promising candidates for the treatment of constipation.

Pharmacological agents currently in clinical trials for disorders in neurogastroenterology

Esophageal, gastrointestinal, and colonic diseases resulting from disorders of the motor and sensory functions represent almost half the patients presenting to gastroenterologists. There have been significant advances in understanding the mechanisms of these disorders, through basic and translational research, and in targeting the receptors or mediators involved, through clinical trials involving biomarkers and patient responses. These advances have led to relief of patients' symptoms and improved quality of life, although there are still significant unmet needs. This article reviews the pipeline of medications in development for esophageal sensorimotor disorders, gastroparesis, chronic diarrhea, chronic constipation (including opioid-induced constipation), and visceral pain.