Effects of Buscopan on human gastrointestinal smooth muscle activity in an ex vivo model: Are there any differences for various sections?

New insights into the characterization of the mechanism of action of hyoscine butylbromide in the human colon ex vivo

INTRODUCTION

Hyoscine butylbromide (HBB) is one of the most used antispasmodics in clinical practice. Recent translational consensus has demonstrated a similarity between human colonic motor patterns studied ex vivo and in vivo, suggesting ex vivo can predict in vivo results. It is unclear whether the mechanism of action of antispasmodics can predict different use in clinical practice. The aim of the present study is to bridge this gap dissecting HBB's role in excitatory and inhibitory neural pathways.

METHODS

309 colon samples from 48 patients were studied in muscle bath experiments. HBB was tested on: 1-spontaneous phasic contractions (SPCs); 2-carbachol-induced contractility; electrical field stimulation (EFS)-induced selective stimulation of 3-excitatory and 4-inhibitory pathways and 5- SPCs and EFS-induced contractions enhanced by neostigmine. Atropine, AF-DX116 (M2 blocker) and DAU-5884 (M3 blocker) were used as comparators.

RESULTS

In the presence of tetrodotoxin (TTX), HBB and atropine 1 μM reduced SPCs. HBB and atropine concentration-dependently reduced carbachol- and EFS-induced contractions. Inhibitory effects of DAU-5884 on EFS-induced contractions were more potent than of AF-DX116. HBB did not affect the off-response associated to neural inhibitory responses. Neostigmine enhanced both SPCs and EFS-induced contractions. In the presence of TTX and ω-conotoxin (GVIA), neostigmine still enhanced SPCs. Addition of HBB and atropine reduced these responses.

CONCLUSIONS

This study demonstrates that HBB inhibits neural cholinergic contractions associated to muscarinic (mainly M3) receptors. HBB has a potential role in reducing colonic spasm induced by the release of acetylcholine from enteric motor neurons and from an atypical source including a potential non-neuronal origin.

Provider-reported use of butylscopolamine in gastrointestinal endoscopy in Germany

Introduction The anti-cholinergic agent hyoscine-N-butylbromide (HBB) is used in gastrointestinal (GI) endoscopy to decrease motility and facilitate endoscopic procedures. Data from clinical studies to support this practice is limited especially for therapeutic procedures. Likewise, patterns of use among endoscopist are largely unclear. This study sought to assess usage of HBB among German-speaking endoscopists. Material and Methods We conducted an anonymous online survey among endoscopists in German-speaking countries. Results A total of 207 physicians participated in the survey. The majority (76.9%) were experienced endoscopists and 92.3% of respondents use HBB at least occasionally during procedures. The reported median stated frequency of HBB use varied greatly between different types of procedures and increased with the complexity of the procedure being performed. HBB was rarely used in diagnostic esophagogastroduodenoscopies (EGD) (median stated frequency 1% of procedures), while use frequency was significantly higher in EGD with endoscopic mucosal resection (EMR) (10%; p=0.002) and EGD with endoscopic submucosal dissection (ESD) (20%; p<0.001). Similarly, use frequency during diagnostic colonoscopy was lower (5%) compared to colonoscopy with EMR (20%, p=0.005) or ESD (42.5%, p<0.001). The highest use frequency was reported for ERCP (50%). The most frequently stated reason to use HBB was facilitation of the procedure (80.6%) followed by increasing diagnostic yield (58.3%). Conclusion German-speaking endoscopists commonly use HBB, most frequently to facilitate complex therapeutic procedures. Given there is almost no data supporting HBB use in therapeutic endoscopy, we suggest that more research is needed to evaluate benefits and risks of this practice.

Antispasmodic Effect of Valeriana pilosa Root Essential Oil and Potential Mechanisms of Action: Ex Vivo and In Silico Studies

Infusions of Valeriana pilosa are commonly used in Peruvian folk medicine for treating gastrointestinal disorders. This study aimed to investigate the spasmolytic and antispasmodic effects of Valeriana pilosa essential oil (VPEO) on rat ileum. The basal tone of ileal sections decreased in response to accumulative concentrations of VPEO. Moreover, ileal sections precontracted with acetylcholine (ACh), potassium chloride (KCl), or barium chloride (BaCl2) were relaxed in response to VPEO by a mechanism that depended on atropine, hyoscine butylbromide, solifenacin, and verapamil, but not glibenclamide. The results showed that VPEO produced a relaxant effect by inhibiting muscarinic receptors and blocking calcium channels, with no apparent effect on the opening of potassium channels. In addition, molecular docking was employed to evaluate VPEO constituents that could inhibit intestinal contractile activity. The study showed that α-cubebene, β-patchoulene, β-bourbonene, β-caryophyllene, α-guaiene, γ-muurolene, valencene, eremophyllene, and δ-cadinene displayed the highest docking scores on muscarinic acetylcholine receptors and voltage-gated calcium channels, which may antagonize M2 and/or M3 muscarinic acetylcholine receptors and block voltage-gated calcium channels. In summary, VPEO has both spasmolytic and antispasmodic effects. It may block muscarinic receptors and calcium channels, thus providing a scientific basis for its traditional use for gastrointestinal disorders.

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.

Safety, efficacy, and maneuverability of a self-propelled capsule endoscope for observation of the human gastrointestinal tract

Background and study aims  We developed a self-propelled capsule endoscope that can be controlled from outside the body with real-time observation. To improve the device, we conducted a clinical trial of total gastrointestinal capsule endoscopy in healthy subjects to ascertain whether our first-generation, self-propelled capsule endoscope was safe and effective for observing the entire human gastrointestinal tract. Patients and methods  After adequate gastrointestinal pretreatment, five healthy subjects were instructed to swallow a self-propelling capsule endoscope and the safety of a complete gastrointestinal capsule endoscopy with this device was assessed. We also investigated basic problems associated with complete gastrointestinal capsule endoscopy. Results  No adverse effects of the magnetic field were identified in any of the subjects. No mucosal damage was noted in any of the subjects with the use of our first-generation, self-propelling capsule endoscope. We found that it took longer than expected to observe the stomach; the view was compromised by the swallowed saliva. The pylorus was extremely difficult to navigate, and the endoscope's fin sometimes got caught in the folds of the small intestine and colon. Conclusions  To resolve the problems associated with the existing self-propelling capsule endoscope, it may be necessary to not only improve the capsule endoscopes, but also to control the environment within the gastrointestinal tract with medications and other means. Our results could guide other researchers in developing capsule endoscopes controllable from outside the body, thus allowing real-time observation.

EphrinB2/ephB2-mediated myenteric synaptic plasticity: mechanisms underlying the persistent muscle hypercontractility and pain in postinfectious IBS

Patients with irritable bowel syndrome (IBS) show pain hypersensitivity and smooth muscle hypercontractility in response to colorectal distension (CRD). Synaptic plasticity, a key process of memory formation, in the enteric nervous system may be a novel explanation. This study aimed to explore the regulatory role of ephrinB2/ephB2 in enteric synaptic plasticity and colonic hyperreactive motility in IBS. Postinfectious (PI)-IBS was induced by Trichinella spiralis infection in rats. Isometric contractions of colonic circular muscle strips, particularly neural-mediated contractions, were recorded ex vivo. Meanwhile, ephrinB2/ephB2-mediated enteric structural and functional synaptic plasticity were assessed in the colonic muscularis, indicating that ephrinB2 and ephB2 were located on enteric nerves and up-regulated in the colonic muscularis of PI-IBS rats. Colonic hypersensitivity to CRD and neural-mediated colonic hypercontractility were present in PI-IBS rats, which were correlated with increased levels of cellular homologous fos protein (c-fos) and activity-regulated cystoskeleton-associated protein (arc), the synaptic plasticity-related immediate early genes, and were ameliorated by ephB2Fc (an ephB2 receptor blocker) or MK801 (an NMDA receptor inhibitor) exposure. EphrinB2/ephB2 facilitated synaptic sprouting and NMDA receptor-mediated synaptic potentiation in the colonic muscularis of PI-IBS rats and in the longitudinal muscle-myenteric plexus cultures, involving the Erk-MAPK and PI3K-protein kinase B pathways. In conclusion, ephrinB2/ephB2 promoted the synaptic sprouting and potentiation of myenteric nerves involved in persistent muscle hypercontractility and pain in PI-IBS. Hence, ephrinB2/ephB2 may be an emerging target for the treatment of IBS.-Zhang, L., Wang, R., Bai, T., Xiang, X., Qian, W., Song, J., Hou, X. EphrinB2/ephB2-mediated myenteric synaptic plasticity: mechanisms underlying the persistent muscle hypercontractility and pain in postinfectious IBS.