Acotiamide hydrochloride (Z-338) enhances gastric motility and emptying by inhibiting acetylcholinesterase activity in rats

[Current status and prospects of using the prokinetic acotiamide in gastroenterology: A review]

Acotiamide is a prokinetic with a novel mechanism of action - an antagonist of muscarinic M1 and M2 receptors and an acetylcholinesterase inhibitor. Acetylcholine is the central mediator of the tone of the muscular components of the gastrointestinal tract, increasing its motor activity. Blockade of presynaptic M1 and M2 receptors neutralizes the inhibitory effect of the feedback mechanism on the acetylcholine synthesis, while inhibition of acetylcholinesterase in the synaptic cleft reduces the acetylcholine degradation. Currently, the clinical efficacy of acotiamide in the population of patients with functional dyspepsia is demonstrated in more than 10 clinical studies in different regions of the world, demonstrating a reduction of the symptoms of the disease during treatment with this agent and an improvement in the quality of life of patients. In addition, the combination of acotiamide with proton pump inhibitors optimizes the management of patients with gastroesophageal reflux disease.

A neural circuit for gastric motility disorders driven by gastric dilation in mice

Introduction

Symptoms of gastric motility disorders are common clinical manifestations of functional gastrointestinal disorders (FGIDs), and are triggered and exacerbated by stress, but the neural pathways underpinning them remain unclear.

Methods

We set-up a mouse model by gastric dilation (GD) in which the gastric dynamics were assessed by installing strain gauges on the surface of the stomach. The neural pathway associated with gastric motility disorders was investigated by behavioral tests, electrophysiology, neural circuit tracing, and optogenetics and chemogenetics involving projections of the corticotropin-releasing hormone (CRH) from the paraventricular nucleus of the hypothalamus (PVN) to acetylcholine (ChAT) neurons in the dorsal motor nucleus of the vagus (DMV).

Results

We found that GD induced gastric motility disorders were accompanied by activation of PVN ^CRH neurons, which could be alleviated by strategies that inhibits the activity of PVN ^CRH neurons. In addition, we identified a neural pathway in which PVN ^CRH neurons project into DMV ^ChAT neurons, modulated activity of the PVN ^CRH →DMV ^ChAT pathway to alleviate gastric motility disorders induced by GD.

Discussion

These findings indicate that the PVN ^CRH →DMV ^ChAT pathway may mediate at least some aspects of GD related gastric motility, and provide new insights into the mechanisms by which somatic stimulation modulates the physiological functions of internal organs and systems.

The rodent model of impaired gastric motility induced by allyl isothiocyanate, a pungent ingredient of wasabi, to evaluate therapeutic agents for functional dyspepsia

Functional dyspepsia (FD) is thought to be mainly based on gastric motility dysfunction and chronic hypersensitivity, yet FD animal models has been reported a few. We studied to establish the mouse model of impaired gastric motility induced by a pungent ingredient of wasabi allyl isothiocyanate (AITC), which is reliable to evaluate prokinetic agents. Male ddY mice were used. Gastric motility was measured by 13C-acetic acid breath test in conscious mice. AITC (80 mM) was given 60 min before the measurement of motility. Prokinetic agents including itopride (30, 100 mg/kg), mosapride (0.1-1 mg/kg), neostigmine (30 μg/kg), acotiamide (10-100 mg/kg), and daikenchuto (100-1000 mg/kg) were given 40 min before the measurement. AITC impaired gastric motility without mucosal damages, which reverted 24 h after AITC treatment. The decreased motility induced by AITC was restored by prokinetic agents such as itopride, mosapride, neostigmine, and acotiamide. In separate experiment, daikenchuto recovered the decreased motility induced by AITC, although daikenchuto had no effect on motility in normal condition. In conclusion, it is considered that the AITC-induced impaired gastric motility mouse model is useful to develop new prokinetic agents for treatment of FD, and to re-evaluate traditional Japanese herbal medicines.

Acotiamide attenuates central urocortin 2-induced intestinal inflammatory responses, and urocortin 2 treatment reduces TNF-α productions in LPS-stimulated macrophage cell lines

BACKGROUND

To determine whether central and in vitro administration of urocortin 2 (Ucn 2) affected intestinal inflammatory responses in LPS-stimulated rat models and macrophage cell lines and acotiamide modified mucosal inflammation in this model.

METHODS

Rats were divided into four groups. LPS-stimulated group (n = 4); LPS- and urocortin 2-treated group (n = 4); LPS- and acotiamide-treated group (n = 4); and LPS-, urocortin 2-, and acotiamide-treated group (n = 4). CD68-, CCR2-, and corticotropin-releasing hormone receptor type 2 (CRHR2)-positive cells were assessed by immunostaining. Myeloperoxidase (MPO) activity was measured. TNF-α, IL-6, and IL-4 levels were measured by ELISA method. Gastric emptying and small intestinal transit time were determined using Evans blue.

KEY RESULTS

Central administration of Ucn 2 significantly aggravated infiltrations of CD68- and CCR2-positive cells in the intestinal mucosa of LPS-stimulated rat models compared to those in LPS treatment alone. Interestingly, acotiamide treatment significantly reduced the migrations of both CD68- and CCR2-positive cells in the jejunum of central Ucn 2-treated LPS-stimulated rat models. Acotiamide significantly reduced the expression levels of IkB-α phosphorylation in LPS- and MCP-1-stimulated NR8383 cells. Central administration of Ucn 2 significantly delayed gastric emptying. In contrast, Ucn 2 stimulation significantly reduced TNF-α and IL-6 productions in LPS-stimulated NR8383 cells and astressin B reversed the inhibition of TNF-α production in stimulated NR8383 cells. Acotiamide (30 μmol/L) significantly reduced TNF-α and IL-6 productions in LPS- and MCP-1-stimulated NR8383 cells.

CONCLUSIONS AND INFERENCES

Central and in vitro treatments of Ucn 2 affected intestinal inflammatory responses, respectively, and acotiamide improved them.

Identification of the Uptake Transporter Responsible for Distribution of Acotiamide into Stomach Tissue

The acetylcholinesterase inhibitor, acotiamide, improves gastric motility and is clinically used to treat functional dyspepsia. The present study aimed to identify the transporters involved in the distribution of acotiamide in stomach tissue. Acotiamide uptake by the gastric cancer-derived model cell line, Hs746 T, was Na⁺- and pH-independent. The initial uptake velocity of acotiamide was saturable with increasing concentrations of acotiamide and was inhibited by selective serotonin reuptake inhibitors, which are potent inhibitors of the plasma membrane monoamine transporter (PMAT). The uptake of acotiamide by PMAT gene-transfected HEK293 cells was saturable, with similar K_m (197.9 μM) values to those of uptake by Hs 746T cells (106 μM). Moreover, immunoreactivity of PMAT was found in the gastric smooth muscle and vascular endothelial cells. These results suggest that PMAT contributes to the distribution of acotiamide in the stomach, where it exerts its pharmacological effects.

Solvates of acotiamide hydrochloride: characterization and phase transformation

Five novel crystals of acotiamide hydrochloride (AH) with solvates dimethyl formide (DMF), dimethyl sulfoxide (DMSO), ethyl acetate (EA) and water (W) [1AH-1W-1DMF, 1AH-1DMSO-I, 1AH-1DMSO-II, 1AH-1W-1DMSO and 2AH-2DMSO-1EA] were characterized using single-crystal X-ray diffraction, powder X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy. The five crystals can be divided into four distinct structural types based on analysis of their similarities; 1AH-1W-1DMF and 1AH-1W-1DMSO are isostructural. The benzene rings in 1AH-1DMSO-I, 1AH-1DMSO-II and 2AH-2DMSO-1EA can rotate 180°, and the intramolecular hydrogen bond changes from an OH...C=O bond to an NH...OH bond relative to what is seen in 1AH-1W-1DMF and 1AH-1W-1DMSO. Phase transformation experiments show that a humidity-induced phase transformation is closely tied to moisture content.

Sub-acute and acute toxicity of Ferula asafoetida and Silybum marianum formulation and effect of the formulation on delaying gastric emptying

BACKGROUND

Delayed gastric emptying play an important role in the pathology of functional dyspepsia. Owing to their functional attributes in alleviating the gastrointestinal disorders, single or polyherbal formulations have gained attention to treat the symptoms of functional dyspepsia. We have investigated the safety and efficacy of a novel formulation of Ferula asafoetida oleo resin and standardized Silybum marianum extract (Asdamarin).

METHODS

The effect of asdamarin on delayed gastric emptying was investigated in Sprague Dawley rats using phenol red method. The acute and sub-acute oral toxicity was evaluated in wistar rats following OECD guidelines 425 and 407 respectively. The data were analyzed by one-way ANOVA using GraphPad Prism 5.0 software.

RESULTS

Oral administration of Asdamarin dose-dependently improved the delay in gastric emptying as evident from the significant increase in the gastrointestinal transit time (p < 0.001). The LD50 of asdamarin was estimated to be more than 2000 mg/kg. Further, in the 28-day sub-acute toxicity study, the administration of 250, 500 and 1000 mg/kg of Asdamarin did not significantly altered the feed and water consuption, body weight change, biochemical and haematological parameters compared to control animals. Macroscopic and histopathological examination of vital organs revealed no toxic signs.

CONCLUSION

The preliminary data from the present study provides the first evidence on the possible effectiveness of novel formulation of F. Asafoatida and S. marianum extracts in alleviating the associated symptoms of functional dyspepsia. The toxicity data indicated that Asdamarin can be considered safe up to 1000 mg/kg dose.

Acotiamide affects antral motility, but has no effect on fundic motility, gastric emptying or symptom perception in healthy participants

BACKGROUND

Acotiamide, a prokinetic agent was shown to be efficacious in the treatment of functional dyspepsia (FD). The exact mechanism of action is incompletely elucidated.

METHODS

This randomized, placebo-controlled, cross-over study aimed to examine the effect of acotiamide on gastric motility, measured as intragastric pressure, gastric emptying (GE) rate and gastrointestinal (GI) symptom perception in healthy volunteers (HVs). Participants were treated with acotiamide (100 mg tid) and placebo for 3 weeks, separated by a 1-week washout period. A daily symptom diary was collected during both treatments. At the end of each treatment period, GE rate and gastric motility were assessed with a ¹³ C-octanoic acid breath test and high-resolution manometry during nutrient infusion, respectively. GI symptom levels were scored during high-resolution manometry. Data were analyzed using mixed models. The study was registered as NCT03402984.

KEY RESULTS

Twenty HVs (10 female, 25 ± 4.1 years, 22.58 ± 2.73 kg/m² ) participated in the study. There was no difference in GE half time between both treatments (P = 0.92). Acotiamide had no effect on fundic pressures before and after nutrient infusion (P = 0.91). However, postprandial antral pressures remained significantly lower compared to placebo (P = 0.015). There was no significant difference in hunger, satiation and GI symptoms scores assessed during IGP measurement and by the daily diary (P > 0.12 for all).

CONCLUSION

Acotiamide is associated with lower antral pressures after nutrient intake, whereas it has no effect on fundic pressures, GE rate and symptom perceptions in HVs. Studies in FD need to elucidate whether lower antral pressures induced by acotiamide underlie postprandial symptom improvement in FD.

Acetylcholinesterase Inhibitors: Beneficial Effects on Comorbidities in Patients With Alzheimer's Disease

Elderly patients with Alzheimer's disease (AD) and other dementias are at high risk of polypharmacy and excessive polypharmacy for common coexisting medical conditions. Polypharmacy increases the risk of drug-drug and drug-disease interactions in these patients who may not be able to communicate early symptoms of adverse drug events. Three acetylcholinesterase inhibitors (ACHEIs) have been approved for AD: donepezil (Aricept), rivastigmine (Exelon), and galantamine (Razadyne). They are also used off-label for other causes of dementia such as Lewy body and vascular dementia. We here report evidence from the literature that ACHEI treatment, prescribed for cognitive impairment, can reduce the load of medications in patients with AD by also addressing cardiovascular, gastrointestinal, and other comorbidities. Using one drug to address multiple symptoms can reduce costs and improve medication compliance.

Choosing an Animal Model for the Study of Functional Dyspepsia

Functional dyspepsia (FD) is a common functional gastrointestinal disorder with pain or discomfort in the upper abdomen as the main characteristic. The prevalence of FD worldwide varies between 5% and 11%. This condition adversely affects attendance and productivity in the workplace. Emerging evidence is beginning to unravel the pathophysiologies of FD, and new data on treatment are helping to guide evidence-based practice. In order to better understand the pathophysiologies of FD and explore better treatment options, various kinds of animal models of FD have been developed. However, it is unclear which of these models most closely mimic the human disease. This review provides a comprehensive overview of the currently available animal models of FD in relationship to the clinical features of the disease. The rationales, methods, merits, and disadvantages for modelling specific symptoms of FD are discussed in detail.

Management of functional dyspepsia: state of the art and emerging therapies

Patients with functional dyspepsia, defined in the 2016 Rome IV criteria as bothersome clinical dyspepsia symptoms, experience markedly reduced quality of life. Several etiologies have been associated with the disorder. In the Rome IV criteria, the brain-gut axis was acknowledged as an important factor in the etiology of functional gastrointestinal (GI) disorders. The distinct subgroups of functional dyspepsia, epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS), are treated differently: acid secretion inhibitors are recommended with patients with EPS, whereas prokinetic drugs as mosapride and acotiamide are recommended for patients with PDS. A previous study has reported that proton pump inhibitors (PPIs) and H₂-blockers were equally effective in functional dyspepsia. A new drug, acotiamide, a muscarinic antagonist and cholinesterase inhibitor, has been shown to improve gastric motility in rodents and dogs, and to reduce PDS symptoms in patients in double-blind multicenter studies. The pharmacological mechanisms of acotiamide remain unknown; whether acotiamide alters gastric emptying and gastric accommodation in patients with functional dyspepsia remains an open question. Other emerging treatment options include Rikkunshito, a herbal medicine that improves gastric emptying through 5-hydroxytryptamine (5-HT)2B-mediated pharmacological action, and tricyclic antidepressants (TCAs). Different drugs are needed to accommodate the clinical symptoms and etiology in individual patients.

A double-blind placebo controlled study of acotiamide hydrochloride for efficacy on gastrointestinal motility of patients with functional dyspepsia

BACKGROUND

Acotiamide is widely used to improve symptoms in patients with functional dyspepsia (FD) in multiple large-scale clinical studies, but there are few reports about the drug's mechanism of action. The aim of this study was to assess the effects of acotiamide on gastric accommodation and gastric emptying, gastrointestinal symptoms, and health-related quality of life (HR-QOL) in a placebo-controlled study.

METHODS

We conducted a randomized, double-blind placebo-controlled study. Fifty Japanese FD patients were randomly assigned to either placebo (n = 25) or acotiamide 100 mg × 3/day for 2 weeks (n = 25). At baseline and at 2 weeks of treatment, we evaluated the patients' gastric motility using scintigraphy to determine the accommodation and emptying values, gastrointestinal symptom rating scale (GSRS), HR-QOL (SF-8), and anxiety and depression scale (HADS).

RESULTS

Four patients failed to complete the medication regimen and were omitted from analysis; data from 24 placebo patients and 22 acotiamide patients were analyzed. Acotiamide significantly increased gastric accommodation compared to the placebo (p = 0.04 vs. p = 0.08; respectively). Acotiamide significantly accelerated gastric emptying (50 % half-emptying time) (p = 0.02 vs. p = 0.59). Acotiamide significantly improved the total GSRS scores compared to placebo (p = 0.0007 vs. p = 0.14). HR-QOL did not differ significantly between the two groups, but acotiamide significantly improved the HADS anxiety score compared to placebo (p = 0.04 vs. p = 0.20).

CONCLUSIONS

Our placebo-controlled study demonstrated that acotiamide significantly increased both gastric accommodation and gastric emptying in Japanese FD patients. Acotiamide also improved the patients' dyspeptic symptoms and anxiety score. Clinical Trials Registry no: UMIN000013544.

Acotiamide improves stress-induced impaired gastric accommodation

BACKGROUND

Gastric accommodation is a reflex reaction related to gastric reservoir function. Psychological stress, such as anxiety, inhibits gastric accommodation in humans. Acotiamide enhances the effect of acetylcholine in the enteric nervous system, enhances gastric contractility, and accelerates delayed gastric emptying. However, the effect of acotiamide on stress-induced impaired gastric accommodation remains unclear. Therefore, we examined the effect of acotiamide on gastric accommodation and stress-induced impaired gastric accommodation using a conscious guinea pig model.

METHODS

A polyethylene bag was inserted through the distal region of the gastric body into the proximal stomach of 5-week-old male Hartley guinea pigs. Gastric accommodation was evaluated by measuring the intrabag pressure in the proximal stomach after oral administration of a liquid meal. In the stress model, animals were subjected to water-avoidance stress. Acotiamide (Z-338) or nizatidine was administered subcutaneously. Fecal output was determined as the number of fecal pellets.

KEY RESULTS

Administration of the liquid meal significantly decreased intrabag pressure, indicating induction of gastric accommodation. Acotiamide treatment prolonged liquid meal-induced gastric accommodation and significantly increased the number of fecal pellets compared to controls. Water-avoidance stress significantly inhibited liquid meal-induced gastric accommodation. Pretreatment with acotiamide significantly improved stress-induced impaired gastric accommodation. The number of fecal pellets in the acotiamide group increased significantly compared to controls. Acotiamide, but not nizatidine, significantly decreased gastric emptying.

CONCLUSIONS & INFERENCES

Acotiamide prolongs gastric accommodation and improves stress-induced impaired gastric accommodation, indicating a potential role for acotiamide in the treatment of functional dyspepsia through its effects on gastric accommodation reactions.

Diagnosis and Treatment Strategy of Achalasia Subtypes and Esophagogastric Junction Outflow Obstruction Based on High-Resolution Manometry

BACKGROUND

Based on Chicago Classification version 3.0, the disorders of esophagogastric junction outflow obstruction (EGJOO) include achalasia (types I, II and III) and EGJOO. Although no curative treatments are currently available for the treatment of the disorders of EGJOO, medical treatments, endoscopic pneumatic dilation (PD), laparoscopic Heller myotomy (LHM), and per-oral endoscopic myotomy (POEM) are usually the sought-after modes of treatment. Since the etiology and pathogenesis might vary depending on the types of EGJOO disorders, treatment strategies should be considered based on those subtypes.

SUMMARY

Based on the accumulated evidences, the treatment strategies of our institution are as follows: effects of medical treatments on achalasia are limited. Either PD or LHM/POEM can be considered a first-line in achalasia type I, according to the patient's wish. PD and POEM can be considered first-line in achalasia types II and III, respectively. Conversely, In EGJOO, medical treatments including drugs like acotiamide and/or diltiazem can be tested as a first-line, and PD and POEM will be considered second and third-line treatments, respectively. Key Messages: The classification of subtypes based on high-resolution manometry will help us consider which treatment option can be selected as a first-line treatment depending upon the subtypes of disorders of EGJOO. Acotiamide has the potential to cure patients with EGJOO.

Effects of Rhizoma Parisdis total saponins and its main compounds on gastric emptying via regulating muscarinic receptors in vitro and in vivo

The aim of this study was to explore the inhibitory effect of Rhizoma Parisdis total Saponins (RPS) and the main monomer compounds (polyphyllin I, II, VI and H) on gastric emptying and gastrointestinal motilityin vitroandin vivo.

L-Arginine L-Glutamate Enhances Gastric Motor Function in Rats and Dogs and Improves Delayed Gastric Emptying in Dogs

Amino acids are not only constituents of proteins, but also have multiple physiologic functions. Recent findings have revealed that ingested amino acids either activate luminal receptors or are metabolized, causing physiologic reactions in the gastrointestinal (GI) tract. We examined the effect of oral L-arginine L-glutamate (ArgGlu), a pharmaceutical amino acid salt used i.v. for the treatment of hyperammonemia, on gastric motor function in rats and dogs. Gastric emptying was determined using phenol red and ¹³C-breath test methods, whereas gastric relaxation was determined using the barostat method. ArgGlu (10-30 mg/kg, p.o.) dose-dependently promoted gastric emptying in rats. This effect was dependent on vagus nerve activation and comparable to that of the prokinetic mosapride. Intragastric ArgGlu (3-30 mg/kg intragastrically) also dose-dependently enhanced adaptive relaxation of rat stomachs, which was negated not by vagotomy of gastric branches, but by pretreatment with N omega-nitro-L-arginine methyl ester (20 mg/kg i.v.), a nitric oxide synthase inhibitor. Its relaxing effect on the stomach was also confirmed in dogs and was equally as efficacious as treatment with sumatriptan (1-3 mg/kg s.c.). ArgGlu (30 mg/kg p.o.) significantly reduced the half gastric emptying time in clonidine-induced delayed gastric emptying of solids in dogs, and its effect was comparable to that of cisapride (3 mg/kg p.o.). This study demonstrated that the pharmaceutical ingredient ArgGlu, currently used i.v., enhanced gastric motor function when administered orally, suggesting that it could be a new oral medicine indicated for treatment of upper GI hypofunction or dysfunction like functional dyspepsia.

Emerging treatments in neurogastroenterology: Acotiamade, a novel treatment option for functional dyspepsia

BACKGROUND

Acotiamide hydrochloride (Z-338) is a new therapeutic agent for functional dyspepsia (FD). In 2013, the use of acotiamide was approved by the Japanese health insurance system.

PURPOSE

The aim of this review is to summarize the present staus of basic and clinical approach to acotiamide for the treatment of functional dyspepsia. The agent inhibits acetylcholinesterase in vitro and enhances muscle motility ex vivo. In phase-II studies, 100 mg three times daily (t.i.d.) was determined to be the optimal dose for the treatment of FD. In phase-III studies, overall treatment efficacy (OTE) was significantly better in the acotiamide group (52.2%) than in the placebo group (34.8%). However, the mechanism of its efficacy needs to be further elucidated. Acotiamide effectively improved FD symptoms, particularly postprandial distress syndrome symptoms, without causing major adverse effects.

A case of advanced systemic sclerosis with severe GERD successfully treated with acotiamide

The majority of systemic sclerosis (SSc) patients have gastrointestinal tract involvement, but therapies of prokinetic agents are usually unsatisfactory. Patients are often compromised by the use of steroid; therefore, a surgical indication including fundoplication has been controversial. There is no report that advanced SSc with severe gastroesophageal reflux disease (GERD) is successfully treated with acotiamide, which is the acetylcholinesterase (AChE) inhibitor designed for functional dyspepsia (FD). We report a 44-year-old woman of SSc with severe GERD successfully treated with acotiamide. She had received medical treatment in our hospital since 2003. She had been aware of the significant gastroesophageal reflux symptoms (e.g., heartburn, chest pain, and dysphagia) due to the development of esophageal hardening associated with SSc since 2014. As a result of upper gastrointestinal series, upper gastrointestinal endoscopy, and 24-h pH monitoring and frequency scale for the symptoms of the GERD (FSSG) scoring, she has been diagnosed with GERD associated with SSc. First of all, she started to take prokinetic agents Rikkunshito and mosapride and proton pump inhibitor; there was no change in reflux symptoms. So, we started to prescribe her the acotiamide.

After oral administration started, reflux symptoms have been improved. Five months after oral administration, FSSG score, a questionnaire for evaluation of the symptoms of GERD, was improved. Since its introduction of acotiamide, the patient has kept free from symptoms for 6 months.

Effect of DA-9701 on the Normal Motility and Clonidine-induced Hypomotility of the Gastric Antrum in Rats

Background/Aims

DA-9701 is a novel prokinetic agent. In the present study, we investigated the effect of DA-9701 on the motility of the gastric antrum in the normal and clonidine-induced hypomotility in an in vivo animal model.

Methods

A strain gauge force transducer was sutured on the gastric antrum to measure the contractile activity in rats. A total of 28 rats were subclassified into the 4 groups: (1) the placebo group, (2) the DA-9701 group, (3) the placebo group in the clonidine-pretreated rats, and (4) the DA-9701 group in the clonidine-pretreated rats. After the basal recording, either placebo (3% [w/v] hydroxypropylmethyl cellulose) or DA-9701 was administered. Contractile signals were measured after the administration and after a meal. In the clonidine-pretreated rats, either placebo or DA-9701 was administered. Contractile signals were measured after the administration and after a meal.

Results

Oral administration of DA-9701 did not significantly alter the motility index of the gastric antrum in the preprandial and postprandial periods, compared with the placebo group. The administration of clonidine decreased the motility index of the gastric antrum in the preprandial and postprandial periods, compared with the administration of placebo. This reduction of the antral motility by the administration of clonidine was not observed in the clonidine-pretreated DA-9701 group. The percentage of the motility index in the postprandial period was significantly greater in the clonidine-pretreated DA-9701 group, compared with the clonidine-pretreated placebo group.

Conclusions

DA-9701 improves the hypomotility of the gastric antrum induced by clonidine, suggesting its gastroprokinetic effect in the pathologic condition.

Anethole restores delayed gastric emptying and impaired gastric accommodation in rodents

Functional dyspepsia (FD), a functional gastrointestinal disorder, is characterized by persistent or recurrent postprandial upper abdominal discomfort and epigastric pain. The high prevalence of FD and associated healthcare costs suggests that treatment of this condition by methods other than prescribed medicines, such as natural products, could be beneficial. Delayed gastric emptying and impaired gastric accommodation play important roles in the development of FD. Anethole (1-methoxy-4-((E)-propenyl)-benzene), a major component of essential fennel oil, has been used as a flavoring, in alcoholic beverage production and in pharmaceutical formulations for many years. In this study, we examined the effects of anethole on delayed gastric emptying and impaired gastric accommodation in rodents. Oral administration of anethole improved clonidine-induced delayed gastric emptying but did not affect normal gastric emptying in mice. Fennel oil and Anchu-san (a Japanese herbal medicine containing anethole) also restored delayed gastric emptying. Furthermore, oral administration of anethole stimulated gastric accommodation in rats. These results suggest that anethole could be beneficial for the treatment of FD.

Effect of neostigmine on gastroduodenal motility in patients with suspected gastrointestinal motility disorders

BACKGROUND

Acetylcholinesterase inhibitors (ACIs), e.g., neostigmine, are known to increase upper and lower gastrointestinal (GI) motility and are used to treat acute colonic pseudoobstruction. However, their effects on gastroduodenal motility in humans are poorly understood. Our hypotheses were that, in patients with suspected GI motility disorders, neostigmine increases gastric and small intestinal motor activity, and these effects are greater in patients with cardiovagal neuropathy, reflecting denervation sensitivity.

METHODS

In this open label study, the effects of neostigmine (1 mg intravenously) on gastroduodenal motor activity recorded with manometry were assessed in 28 patients with a suspected GI motility disorder. Cardiovagal function was assessed with the heart rate response to deep breathing and GI transit by scintigraphy.

KEY RESULTS

The final diagnoses were gastroparesis (6 patients), gastroparesis with intestinal neuropathy (3 patients), intestinal neuropathy or pseudoobstruction (5 patients), functional dyspepsia (6 patients), chronic abdominal pain (3 patients), mechanical small intestinal obstruction (3 patients), and pelvic floor dysfunction (2 patients). Neostigmine increased both antral and intestinal phasic pressure activity (p < 0.001). Neostigmine increased antral and intestinal pressure activity in 81% and 50% of patients with reduced postprandial antral and intestinal contractile responses to meal, respectively. The antroduodenal pressure response to neostigmine was not higher in patients with cardiovagal dysfunction.

CONCLUSIONS & INFERENCES

Neostigmine increased antral and intestinal motor activity in patients with hypomotility, including intestinal dysmotility. These responses to neostigmine were not greater in patients with cardiovagal dysfunction. The use of longer-acting ACIs for treating antroduodenal dysmotility warrant further study.

Aldioxa improves delayed gastric emptying and impaired gastric compliance, pathophysiologic mechanisms of functional dyspepsia

Delayed gastric emptying and impaired gastric accommodation (decreased gastric compliance) play important roles in functional dyspepsia (FD). Here we screen for a clinically used drug with an ability to improve delayed gastric emptying in rats. Oral administration of aldioxa (dihydroxyaluminum allantoinate) partially improved clonidine- or restraint stress-induced delayed gastric emptying. Administration of allantoin, but not aluminium hydroxide, restored the gastric emptying. Both aldioxa and allantoin inhibited clonidine binding to the α-2 adrenergic receptor, suggesting that antagonistic activity of the allantoin moiety of aldioxa on this receptor is involved in the restoration of gastric emptying activity. Aldioxa or aluminium hydroxide but not allantoin restored gastric compliance with restraint stress, suggesting that aluminium hydroxide moiety is involved in this restoration. We propose that aldioxa is a candidate drug for FD, because its safety in humans has already been confirmed and its ameliorating effect on both of delayed gastric emptying and impaired gastric compliance are confirmed here.

Effects of acotiamide on esophageal motor function and gastroesophageal reflux in healthy volunteers

Background

The prevalence of gastroesophageal reflux disease (GERD) has been increasing worldwide, with proton pump inhibitor (PPI) administration the current mainstay therapy for affected individuals. However, PPI efficacy is insufficient especially for non-erosive reflux disease. Although it has been reported that prokinetic drugs improve GERD, their effects on esophageal function remain to be clearly investigated. In the present study, we evaluated the direct effects of acotiamide, a novel prokinetic agent for the treatment of functional dyspepsia, on esophageal motor function and gastroesophageal reflux.

Methods

Ten adult healthy volunteers (average age 24 years, range 20–36 years; 7 males, 3 females) were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure with and without acotiamide administration were recorded using high resolution manometry using a cross-over protocol. Total and acidic reflux levels for 24 h and during the postprandial period were also recorded using a multichannel intraluminal impedance and pH monitoring system. Data were analyzed blind by one observer.

Results

Acotiamide at a standard dose of 300 mg/day did not significantly stimulate esophageal motor function. Although the frequency of swallows with weak contraction tended to decrease with acotiamide administration, the difference as compared to no administration was not statistically significant. In addition, the drug neither decreased total or postprandial gastroesophageal acid/non-acid reflux events nor accelerated esophageal clearance time.

Conclusions

Acotiamide, a novel gastrointestinal motility modulator, at a standard dose did not significantly affect esophageal motor functions or gastroesophageal reflux in healthy adults. Additional investigations with GERD patients are necessary to elucidate its clinical significance.

Trial registration

This study was registered on 1st August 2013 with the University Hospital Medical Information Network (UMIN) clinical trials registry, as number: UMIN000011260.

Physiologically-Based Pharmacokinetic and Pharmacodynamic Modeling for the Inhibition of Acetylcholinesterase by Acotiamide, A Novel Gastroprokinetic Agent for the Treatment of Functional Dyspepsia, in Rat Stomach

Purpose

Acotiamide, a gastroprokinetic agent used to treat functional dyspepsia, is transported to at least two compartments in rat stomach. However, the role of these stomach compartments in pharmacokinetics and pharmacodynamics of acotiamide remains unclear. Thus, the purpose of this study was to elucidate the relationship of the blood and stomach concentration of acotiamide with its inhibitory effect on acetylcholinesterase (AChE).

Methods

Concentration profiles of acotiamide and acetylcholine (ACh) were determined after intravenous administration to rats and analyzed by physiologically-based pharmacokinetic and pharmacodynamic (PBPK/PD) model containing vascular space, precursor pool and deep pool of stomach.

Results

Acotiamide was eliminated from the blood and stomach in a biexponential manner. Our PBPK/PD model estimated that acotiamide concentration in the precursor pool exceeded 2 μM at approximately 2 h after administration. Acotiamide inhibited AChE activity in vitro with a 50% inhibitory concentration of 1.79 μM. ACh reached the maximum concentration at 2 h after administration.

Conclusions

Our PBPK model well described the profile of acotiamide and ACh concentration in the stomach in the assumption that acotiamide was distributed by carrier mediated process and inhibited AChE in the precursor pool of stomach. Thus, Acotiamide in the precursor pool plays an important role for producing the pharmacological action.

Effect of acotiamide on gastric emptying in healthy adult humans

BACKGROUND

Acotiamide is a first-in-class drug that is used to treat functional dyspepsia (FD). It is considered that acotiamide acts as an antagonist on muscarinic autoreceptors in the enteric nervous system and inhibits acetylcholinesterase activity. We examined the effect of acotiamide on gastric emptying in healthy adult humans.

MATERIALS AND METHODS

Twelve healthy adult males were enrolled in this double-blind crossover study. Acotiamide or placebo was administered orally in the 12 subjects 30 min before ingestion of a nutritional liquid meal (400 Kcal/400 mL). Six of the 12 participants took 100 mg of acotiamide or placebo, and six of the 12 participants took 300 mg of acotiamide or placebo in a double-blind crossover fashion. All subjects underwent measurement of gastric emptying by the (13) C breath test.

RESULTS

After the meal with placebo was ingested, the %dose/h curve ascended. The %dose/h curve after a meal with 100 or 300 mg of acotiamide ascended in an identical manner compared with the results with placebo. No significant differences were observed at any studied time point, and there were no significant changes in gastric emptying parameters (gastric emptying coefficient, t-1/2ex and t-lag ex).

CONCLUSIONS

A single administration of 100 or 300 mg of acotiamide did not affect gastric emptying after a liquid meal in healthy adult humans. Acotiamide has profound effects on restoring delayed gastric emptying and impaired accommodation in patients with FD but may have no effect on gastric emptying in healthy subjects. Such pharmacological actions have not been observed in previous gastroprokinetic studies.

Emerging drugs for the treatment of gastroparesis

INTRODUCTION

Gastroparesis presents with symptoms of gastric retention with findings of delayed gastric emptying on diagnostic testing. Manifestations of gastroparesis are disabling in severe cases and lead to significant health resource utilization. Current therapies often are ineffective, may exhibit tolerance on chronic administration or produce prominent side effects in large patient subsets.

AREAS COVERED

This review assessed literature on drugs with theoretical efficacy in gastroparesis including medications that accelerate gastric emptying, reduce nausea and vomiting, or act as neuromodulators to reduce gastric sensitivity. Numerous agents exhibit diverse actions to modify gastric sensorimotor function in animal models; however, few medications are in controlled testing in gastroparesis. Prokinetic drugs with promise for this condition include investigational serotonin 5-HT4 agonists, motilin agonists, dopamine D2 antagonists, ghrelin agonists and an agent with combined muscarinic antagonist and acetylcholinesterase inhibitory effects. Other antiemetics and complementary and alternative formulations may be effective for some symptoms.

EXPERT OPINION

Development of effective novel therapies of gastroparesis without the neurotoxicity and cardiac arrhythmogenic effects of current agents will mandate a better definition of the gastric and extragastric factors responsible for the pathogenesis of the varied clinical manifestations of this disorder.

Pathophysiology and pharmacotherapy of gastroparesis: current and future perspectives

INTRODUCTION

Gastroparesis is an important clinical disorder characterised by delayed gastric emptying in the absence of mechanical outlet obstruction. Idiopathic, diabetes and postsurgical causes represent the most common aetiologies. The condition commonly manifests as upper gastrointestinal symptoms, including nausea, vomiting, postprandial fullness, early satiety, abdominal pain and bloating.

AREAS COVERED

This paper provides a review of the prevalence, pathophysiology and clinical features associated with gastroparesis, with a particular focus on current pharmacological management options and novel and emerging therapies. A literature search was undertaken using the search terms: gastroparesis, diabetic gastroparesis, idiopathic gastroparesis, gastric emptying, prokinetic, metoclopramide, domperidone, erythromycin, motilin, alemcinal, KC11458, mitemcinal, ghrelin, TZP-101, TZP-102, RM-131, tegaserod, prucalopride, naronapride, velusetrag, levosulpiride, itopride, botulinum toxin, gastric electrical stimulation, Enterra.

EXPERT OPINION

Strategies for the management of gastroparesis include correction of malnutrition, dehydration and electrolyte imbalance, relief of symptoms by appropriate use of prokinetic and antiemetic agents and, in patients with gastroparesis associated with diabetes or critical illness-induced hyperglycaemia, optimisation of glycaemic control. Conventional prokinetic agents form the mainstay of treatment. While novel pharmacotherapies are in development, compelling evidence for their efficacy, particularly in symptom relief, remains to be established.

Inhibitory effect of ramosetron on corticotropin releasing factor- and soybean oil-induced delays in gastric emptying in rats

BACKGROUND AND AIM

Symptoms of functional dyspepsia (FD) are highly prevalent in patients with irritable bowel syndrome (IBS). However, the effects of therapeutic agents for IBS on the pathophysiology of FD are unclear. In this study, therefore, we examined the effects of ramosetron, a serotonin 5-HT(3) receptor antagonist, on corticotropin releasing factor (CRF)- and soybean oil-induced delays in gastric emptying of rats, in comparison with anti-diarrheal agent and spasmolytics. The involvement of 5-HT and the 5-HT(3) receptor in delayed gastric emptying was also evaluated.

METHODS

Corticotropin releasing factor was administered intravenously to rats 10min before oral administration of 0.05% phenol red solution, and the amount remaining in the stomach was measured after 30min. Soybean oil was administered orally with glass beads, and the number of residual beads in the stomach was counted 1h later.

RESULTS

Both CRF and soybean oil inhibited gastric emptying dose-dependently. Ramosetron and itopride, a gastro-prokinetic agent, significantly reduced both CRF- and soybean oil-induced delays in gastric emptying, while an anti-diarrheal agent and spasmolytics aggravated them. Pretreatment with p-chlorophenylalanine for 2days to reduced the synthesis of endogenous 5-HT diminished the effects of both CRF and soybean oil on gastric emptying. A 5-HT(3) receptor agonist m-chlorophenylbiguanide suppressed gastric emptying of both phenol red and glass beads, and those effects were reversed by ramosetron.

CONCLUSIONS

These results suggest that CRF and soybean oil suppress gastric emptying in rats by activating 5-HT(3) receptors, and that by antagonizing these receptors, ramosetron may ameliorate symptoms of FD in clinical settings.

Acotiamide, a novel gastroprokinetic for the treatment of patients with functional dyspepsia: postprandial distress syndrome

Functional dyspepsia (FD) is a highly prevalent condition with major socioeconomic and healthcare impact. To date, no pharmacological treatment for FD has been approved. The Rome consensus proposed to subdivide FD into postprandial distress syndrome (PDS), characterized by meal-related symptoms and epigastric pain syndrome, characterized by pain and burning. Acotiamide (Z-338 or YM443) is a new drug, developed for the treatment of FD. Acotiamide enhances acetylcholine release from enteric neurons through muscarinic receptor antagonism and acetycholinesterase inhibition, thereby enhancing gastric emptying and gastric accommodation. Acotiamide was evaluated in FD in clinical studies in Europe, Japan and the USA, beneficial effects were observed for the PDS symptoms of postprandial fullness and early satiation, with a dose of 100 mg three-times a day. A 4-week placebo-controlled Phase III study in PDS patients in Japan confirmed efficacy of acotiamide in relieving postprandial fullness, early satiation and upper abdominal bloating.

Acotiamide, a new orally active acetylcholinesterase inhibitor, stimulates gastrointestinal motor activity in conscious dogs

BACKGROUND Acotiamide hydrochloride (acotiamide), a novel selective acetylcholinesterase (AChE) inhibitor, has proven significantly effective in treating functional dyspepsia (FD) in clinical trials, particularly in alleviating meal-related symptoms. In the present study, we examined the gastrointestinal prokinetic effects of acotiamide administered orally or intraduodenally in conscious dogs and investigated in vivo and ex vivo anti-AChE activity of acotiamide to clarify its mechanism of prokinetic action.

METHODS

Gastrointestinal motility was measured in conscious dogs with chronically implanted force transducers.

KEY RESULTS

Oral administration of acotiamide stimulated postprandial gastroduodenal and colonic motor activities. Measurement of gastrointestinal motility showed that acotiamide, like itopride and mosapride, enhanced gastric antral motility. Further, acotiamide markedly improved clonidine (an α(2) -adrenoceptor agonist)-induced hypomotility in a dog model of gastric motor dysfunction. The postprandial gastric antral motility enhanced by acotiamide was completely abolished on treatment with the muscarinic receptor antagonist atropine. Results of an in vivo experiment on anti-AChE activity showed clearly increased acetylcholine-induced gastric motility on intraduodenal administration of acotiamide, just as observed with the AChE inhibitor neostigmine. Further, in ex vivo experiment, intraduodenal administration of acotiamide significantly inhibited AChE activity in canine gastric antrum.

CONCLUSIONS & INFERENCES

Our findings revealed that acotiamide administered through the alimentary tract exerts gastroprokinetic action via cholinergic pathways by inhibiting AChE activity. These results may also confirm the mechanism of action in clinical efficacy of acotiamide on FD.

Inhibitory effect of Suaeda asparagoides (Miq.) extract on the motility of rat gastric antrum is mediated by β-adrenoceptor

Suaeda asparagoides (Miq.) has long been used as a Korean folk herbal medicine for the treatment of functional gastrointestinal disorders. However, reports on its pharmacological activity on gastrointestinal motility are scarce. The present study investigated the effects of Suaeda asparagoides water fraction of the extract (SAWF) on antral motility in vitro. Muscle strips from rat gastric antrum were set up in an organ bath in a circular orientation. SAWF (100 µg/mL) inhibited the spontaneous contraction of antral circular muscle strips. These inhibitory effects were not significantly affected by tetrodotoxin (1 µM), N^ω-Nitro-L-arginine methyl ester hydrochloride (100 µM), 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (10 µM), ryanodine (10 µM) and phentolamine (10 µM). SAWF-induced inhibition was mostly restored by cyclopiazonic acid (10 µM). Furthermore, the β-adrenergic receptor antagonist, propranolol (10 µM), abolished SAWF-induced inhibition. These results suggest that SAWF may exert its activity on gastrointestinal smooth muscle via â-adrenergic receptors and sarcoplasmic reticulum Ca²⁺ ATPase.