Effect of rikkunshito on gastric sensorimotor function under distention

Clinical efficacy of Yukgunja-tang combined with a proton pump inhibitor for refractory gastroesophageal reflux disease: study protocol for randomized, double-blind, double-dummy clinical trial

BACKGROUND

Yukgunja-tang (YGJ) is an herbal prescription used to treat the symptoms of gastroesophageal reflux disease (GERD). Although many preclinical and clinical studies on YGJ have been conducted on GERD, there is a lack of evidence from blinded studies to exclude placebo effects. Therefore, this protocol proposes a clinical trial that is single-centered, randomized, double-blinded, double-dummy to objectively evaluate the efficacy and safety of co-administered YGJ and rabeprazole (RPZ) in patients with GERD previously treated with proton pump inhibitors (PPIs) and still experiencing symptoms.

METHODS

A total of 86 participants with refractory GERD (rGERD) will be randomized in a 1:1 ratio to the treatment [YGJ and RPZ (10 mg/d)] and control groups [double-dose RPZ (20 mg/d)] for 4 weeks of treatment (weeks 0-4) followed by 4 weeks of follow-up (weeks 4-8). The Frequency Scale for the Symptoms of GERD will be analyzed for the primary endpoint. Reflux Disease Questionnaire, Reflux Symptom Score, GERD-Health Related Quality of Life, Overall Treatment Evaluation, Spleen Qi Deficiency Questionnaire, Damum Questionnaire, and dyspepsia Visual Analogue Scale will be used to evaluate treatment effects on GERD related symptoms and quality of life and to compare treatment effects by subgroups. Safety tests will be analyzed by investigating adverse events.

DISCUSSION

This clinical trial will be the first rigorous double-blind, double-dummy, placebo-controlled study to precisely evaluate the efficacy and safety of the combination of YGJ and PPIs in the treatment of rGERD. The results of this study will provide a reliable clinical basis for selecting botanical drug treatments for patients with rGERD.

TRIAL REGISTRATION

Clinical Research Information Service (registration number: KCT0008600, July 13, 2023, https://cris.nih.go.kr ).

Treatment of dyspeptic symptoms with YamatoGast. A non-interventional study of a registered traditional herbal Rikkunshito extract product from Japanese Kampo Medicine in routine practice in Germany

INTRODUCTION

Dyspeptic symptoms belong to the most frequent reasons to seek medical advice and are a burden both for the individual affected and the healthcare system. In Japan, the traditional herbal Kampo prescription rikkunshito has proven benefit for this indication.

METHODS

In a prospective, multicentre, non-interventional study (NIS), the effectiveness, safety, and tolerability of a two-week treatment with the registered rikkunshito extract product YamatoGast was assessed in German patients with an acute episode of dyspeptic symptoms of functional origin under real-world conditions. The primary endpoint was the responsiveness to treatment assessed by the overall treatment effect (OTE) score. Secondary endpoints were the change in severity of dyspeptic symptoms and the change in quality of life (QoL). Safety evaluation was based on reported adverse drug reactions, drug compliance, and ratings of tolerability by physicians and patients.

RESULTS

Sixty-six patients were enrolled (mean age 48.9 years, 74% females). The treatment was well tolerated and highly beneficial, as expressed by pronounced responder rates of 78.9% for the primary endpoint OTE. All secondary endpoints were also met. The severity of dyspeptic symptoms significantly improved by 62-77% compared to baseline, confirmed by a remarkable improvement of QoL. Significant symptom relief started from the third day of treatment onwards.

CONCLUSION

In this non-interventional study, two-week treatment with YamatoGast resulted in a significant improvement of dyspeptic symptoms and was associated with high patient response and satisfaction. YamatoGast was confirmed as a safe and clinically relevant therapeutic option for patients suffering upper gastrointestinal complaints in routine practice.

Treatment of nausea and vomiting associated with cerebellar infarction using the traditional herbal medicines banhabaekchulcheonma-tang and oryeong-san: Two case reports (CARE-complaint)

RATIONALE

Metoclopramide is commonly used to treat nausea and vomiting. However, long-term administration of metoclopramide is associated with various adverse effects, and its therapeutic effects are short-lasting. Hence, traditional East Asian medicine has received increasing attention as a short-term strategy for treating these symptoms.

PATIENT CONCERNS

The present report discusses the cases of a 71-year-old man and an 80-year-old woman diagnosed with cerebellar infarction. Both patients reported nausea and vomiting, which appeared during hospitalization following cerebellar infarction.

DIAGNOSES

One patient was diagnosed with a left cerebellar infarction and hemorrhagic transformation, while the other was diagnosed with a bilateral cerebellar infarction.

INTERVENTIONS

Both patients took Banhabaekchulcheonma-tang (BT) and Oryeong-san (OS) extracts.

OUTCOMES

The patient in Case 1 experienced a rapid decrease in nausea from day 5 of BT and OS administration, and metoclopramide was discontinued on day 7. The patient in Case 2 experienced a clear decrease in the number of vomiting episodes from day 6 of BT and OS administration and did not take metoclopramide thereafter.

LESSONS

Other than drugs used to mitigate symptoms, there are no suitable treatments available for nausea and vomiting caused by cerebellar infarction. In the present cases, nausea and vomiting remained unresolved even after 3 weeks of treatment with conventional therapies; however, these symptoms significantly improved after administration of the traditional East Asian herbal medicines BT and OS, and there were no recurrences. These cases demonstrate that traditional herbal medicine can reduce the side effects associated with long-term administration of metoclopramide and help patients resume their daily lifestyle. In addition, BT and OS treatment can facilitate administration of other drugs, highlighting its potential to aid in the treatment of stroke. Further research including relevant clinical trials is required to obtain more conclusive evidence.

Ghrelin Enhancer, the Latest Evidence of Rikkunshito

Rikkunshito is a Japanese herbal medicine (Kampo) that has been attracting attention and researched by many researchers not only in Japan but also worldwide. There are 214 rikkunshito articles that can be searched on PubMed by August 2021. The reason why rikkunshito has attracted so much attention is due to an epoch-making report (Gastroenterology, 2008) discovered that rikkunshito promotes the secretion of the orexigenic peptide ghrelin. Since then, many researchers have discovered that rikkunshito has a direct effect on the ghrelin receptor, GHS-R1a, and an effect of enhancing the ghrelin signal to the brain. Additionally, a lot of evidence that rikkunshito is expected to be effective for various gastrointestinal diseases have also been demonstrated. Numerous basic and clinical studies have suggested that rikkunshito affects (i) various discomforts caused by anticancer drugs, gastroesophageal reflux disease, functional dyspepsia, (ii) various stress-induced anorexia, (iii) hypophagia in the elderly, and (iv) healthy lifespan. In this review, as one who discovered the ghrelin enhancer effect of rikkunshito, we will review the research of rikkunshito so far and report on the latest research results.

Rikkunshito as a Therapeautic Agent for Functional Dyspepsia and its Prokinetic and Non-Prokinetic Effects

Prokinetics is one of the therapeutic agents for functional and motility disorders of the stomach. However, its efficacy is limited. Kampo medicine is a unique medical system that was developed in Japan. In Kampo medicine, herbal medicine is prescribed based on the patient’s condition. Therefore, even for functional and motility disorders of the stomach, some herbal medicines are considered as a therapeutic option. Recently, there has been an increase in evidence for the efficacy or the mechanism of herbal medicine for functional and motility disorders of the stomach. Among these, rikkunshito is a well-studied herbal medicine that could be used as an alternative to prokinetics. In this review, we discuss the possibilities of rikkunshito for functional dyspepsia with its prokinetic and non-prokinetic effects and provide an overview of their current use with a focus on their therapeutic mechanism.

Efficacy of rikkunshito in patients with functional heartburn: a prospective pilot study

BACKGROUND

Although the efficacy of rikkunshito in patients with treatment-resistant non-erosive gastroesophageal reflux disease (NERD) has been reported, it is unclear for which subgroups of NERD patients (per the Rome IV criteria) rikkunshito is effective. The objective of this study was to investigate the efficacy of rikkunshito in patients with functional heartburn.

METHODS

Ten patients with functional heartburn who experienced symptoms of dyspepsia were enrolled. The patients were administered rikkunshito for 8 weeks. The frequency scale for the symptoms of GERD (FSSG), Japanese translation of quality of life in reflux and dyspepsia questionnaire (QOLRAD-J), and hospital anxiety and depression scale (HADS) were evaluated before and 4 and 8 weeks after administration. Overall treatment efficacy (OTE) was evaluated 8 weeks after administration.

RESULTS

One patient was discontinued 4 weeks after administration because of voluntary withdrawal. Total FSSG score was significantly (P = 0.039) lower 8 weeks after treatment or at discontinuation (13.2 ± 8.0) than before treatment (18.3 ± 10.7). Although QOLRAD-J score tended to increase 8 weeks after treatment or at discontinuation compared with before treatment, no significant difference was observed. HADS score did not decrease significantly 8 weeks after treatment or at discontinuation compared with before treatment. However, a correlation was found between total FSSG and HADS anxiety scores (correlation coefficient: 0.684, P = 0.027).

CONCLUSIONS

This was the first study to investigate the efficacy of rikkunshito in patients with functional heartburn. Rikkunshito may be effective in these patients.

Complementary and Alternative Medicine for Functional Gastrointestinal Disorders

The relevance of functional gastrointestinal (GI) disorders and their impact on quality of life for many patients has become an increasingly important topic in gastroenterology. A gastroenterologist can expect to see 40% of patients for motility and functional GI disorders, thus highlighting the necessity for physicians to have a strong foundation of knowledge in treatment strategies for these patients with complex disorders. A significant number of patients who suffer with functional GI disorders turn to complementary and alternative therapies to maintain control over their symptoms and often are happy with therapeutic results. This narrative presents information and treatment algorithms for the gastroenterologist to better understand and use some of the most common complementary and alternative therapies for patients with functional dyspepsia, nausea and vomiting, and irritable bowel syndrome.

The effect of rikkunshito on gastrointestinal symptoms and gastric motor function: The first study in a Belgian functional dyspepsia population

BACKGROUND

Rikkunshito, a traditional Kampo medicine, has shown efficacy to treat functional dyspepsia (FD) in controlled trials in Japan. Its putative benefit for European patients and mechanism of action has not been established.

METHODS

This study examined the effect of rikkunshito on gastric motility and GI symptom perception in FD-PDS patients in a randomized, placebo-controlled, cross-over study. After a 2-week run-in period, patients received rikkunshito or matching placebo (2.5 g t.i.d.) for 4 weeks, separated by a 4-week washout period. Symptoms were assessed by the Leuven Postprandial Distress Scale (LPDS) diary throughout the study. At baseline and after both treatment arms, intragastric pressure (IGP) was measured to evaluate gastric accommodation and gastric motility. Simultaneously, GI symptoms were scored on a 100 mm visual analogue scale. Validated symptom questionnaires (PAGI-SYM, VSI, DSS, and PHQ) were completed each study visit.

KEY RESULTS

Twenty-three patients completed the study (33 ± 14 years, 22.7 ± 3.22 kg/m² ). Intragastric pressure was numerically, but not significantly, lower after rikkunshito compared with baseline and placebo (P = .14). No differences were found in gastric accommodation, nutrient volume tolerance, and symptoms assessed during IGP measurements. Early satiation and postprandial fullness (daily diary) decreased after rikkunshito compared with baseline (P < .041 for both). Placebo also improved most other symptoms assessed. No significant changes in VSI scores occurred. No adverse reactions occurred.

CONCLUSIONS

Rikkunshito did not alter gastric motility. Treatment with rikkunshito improved upper GI symptoms in FD patients but similarly high placebo effects were observed using the LPDS diary, PAGI-SYM, SF-NDI, and DSS scores. Rikkunshito was safe and well-tolerated.

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

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

Role of Bitter Taste Receptors in Regulating Gastric Accommodation in Guinea Pigs

Taste stimulants play important roles in triggering digestion and absorption of nutrients and in toxin detection, under the control of the gut-brain axis. Bitter compounds regulate gut hormone secretion and gastrointestinal motility through bitter taste receptors (TAS2Rs) located in the taste buds on the tongue and in the enteroendocrine cells. Gastric accommodation (GA) is an important physiologic function. However, the role of TAS2R agonists in regulating GA remains unclear. To clarify whether GA is influenced by bitter stimulants, we examined the effect of TAS2R agonist denatonium benzoate (DB), administered intraorally and intragastrically, by measuring the consequent intrabag pressure in the proximal stomach of guinea pigs. Effects of the Kampo medicine rikkunshito (RKT) and its bitter components liquiritigenin and naringenin on GA were also examined. Intraoral DB (0.2 nmol/ml) administration enhanced GA. Intragastric DB administration (0.1 and 1 nmol/kg) promoted GA, whereas higher DB doses (30 μmol/kg) inhibited it. Similar changes in GA were observed with intragastric (1000 mg/kg) and intraoral (200 mg/ml) RKT administration. Liquiritigenin and naringenin also promoted GA. These findings suggest that GA is affected by the stimulation of TAS2Rs in the oral cavity or gut in guinea pigs.

An Herbal Medicine, Yukgunja-Tang is more Effective in a Type of Functional Dyspepsia Categorized by Facial Shape Diagnosis: A Placebo-Controlled, Double-Blind, Randomized Trial

INTRODUCTION

Functional dyspepsia (FD) is a functional gastrointestinal disorder characterized by persistent upper dyspeptic symptoms without organic lesions. There is no standard therapy for FD. Yukgunja-tang (YGJT) is an herbal medicine used for treating upper gastrointestinal symptoms in Asia. Studies on the effect of YGJT on FD have been conducted. However, the results were inconsistent. In Hyungsang medicine, traditional Korean medicine, FD patients are classified into bladder body (BB) or gallbladder body (GB) subtypes by the shape and angle of their faces. Each subtype may have different characteristics, physiology, and pathology of the same disease. YGJT is more effective for patients with BB subtype. The three-dimensional facial shape diagnostic system (3-FSDS) was shown to be effective in diagnosing BB or GB subtypes. This study aimed to investigate the effect of YGJT on FD patients classified using the 3-FSDS.

MATERIALS AND METHODS

The current study was a placebo-controlled, double-blinded, randomized, two-center trial. Eligible patients were diagnosed with either BB or GB FD subtype using the 3-FSDS. Ninety-six participants (48 BB and 48 GB subtypes) were randomly allocated to treatment or control groups in a 2:1 ratio. YGJT or placebo was administered for eight weeks. The primary outcome was assessed using the total dyspepsia symptom scale (TDS), while the secondary outcomes were assessed using the single dyspepsia symptom scale (SDS), proportion of responders, visual analog scale, Nepean dyspepsia index, functional dyspepsia-related quality of life, and spleen qi deficiency questionnaire.

RESULTS AND DISCUSSION

The result of TDS showed the superior effect of YGJT on BB over GB subtype. The subgroup analysis of TDS and SDS scores showed the superior effect of YGJT over placebo. Other outcome variables did not show any significant differences between groups.

CONCLUSION

YGJT may be considered for FD patients diagnosed with BB subtype using 3-FSDS.

Rikkunshito simultaneously improves dyspepsia correlated with anxiety in patients with functional dyspepsia: A randomized clinical trial (the DREAM study)

BACKGROUND

Functional dyspepsia (FD), a heterogeneous disorder, involves multiple pathogenetic mechanisms. Developing treatments for FD has been challenging. We performed a randomized, placebo-controlled, double-blind clinical trial to determine the efficacy of rikkunshito, a Japanese herbal medicine, in FD patients.

METHODS

FD patients (n = 192) who met the Rome III criteria without Helicobacter pylori infection, predominant heartburn, and depression were enrolled at 56 hospitals in Japan. After 2 weeks of single-blind placebo treatment, 128 patients with continuous symptoms were randomly assigned to 8 weeks of rikkunshito (n = 64) or placebo (n = 61). The primary efficacy endpoint was global assessment of overall treatment efficacy (OTE). The secondary efficacy endpoints were improvements in upper gastrointestinal symptoms evaluated by the Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index (PAGI-SYM), the Global Overall Symptom scale (GOS), and the modified Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (m-FSSG), and psychological symptoms evaluated by the Hospital Anxiety and Depression Scale (HADS).

KEY RESULTS

Rikkunshito increased OTE compared to placebo at 8 weeks (P = .019). Rikkunshito improved upper gastrointestinal symptoms (PAGI-SYM, GOS, and m-FSSG) at 8 weeks, especially postprandial fullness/early satiety (P = .015 and P = .001) and bloating (P = .007 and P = .002) of the PAGI-SYM subscales at 4 weeks and 8 weeks. Improvement of HADS at 8 weeks (P = .027) correlated with those of PAGI-SYM (r = .302, P = .001), GOS (r = .186, P = .044), and m-FSSG (r = .462, P < .001), postprandial fullness/early satiety (r = .226, P = .014), dyspepsia (r = .215, P = .019), and PDS (r = .221, P = .016).

CONCLUSION & INFERENCES

Rikkunshito may be beneficial for FD patients to simultaneously treat gastrointestinal and psychological symptoms.

Complementary and alternative treatment in functional dyspepsia

Introduction and aim

The popularity of complementary and alternative medicine (CAM) in treating functional gastrointestinal disorders (FGIDs) has steadily increased in Western countries. We aimed at analyzing available data on CAM effectiveness in functional dyspepsia (FD) patients.

Methods

A bibliographical search was performed in PubMed using the following keywords: "complementary/alternative medicine," "hypnosis," "acupuncture" and/or "functional dyspepsia."

Results

In community settings, almost 50% of patients with FGIDs used CAM therapies. Herbal remedies consist of multi-component preparations, whose mechanisms of action have not been systematically clarified. Few studies analyzed the effectiveness of acupuncture in Western countries, yielding conflicting results and possibly reflecting a population bias of this treatment. Hypnosis has been extensively used in irritable bowel syndrome, but few data support its role in treating FD.

Conclusions

Although some supporting well-designed studies have been recently performed, additional randomized, controlled trials are needed before stating any recommendation on CAM effectiveness in treating FD.

Open Label Trial of the Efficacy and Safety Profile of Rikkunshito used for the Treatment of Gastrointestinal Symptoms in Patients with Parkinson's Disease: A Pilot Study

BACKGROUND

Patients with Parkinson's disease (PD) usually experience distress related not only to motor dysfunction, but also to nonmotor symptoms, including gastrointestinal dysfunction.

OBJECTIVE

The purpose of this pilot study was to evaluate the efficacy and safety profile of a traditional Japanese medicine, rikkunshito (RKT), used for the treatment of gastrointestinal symptoms, associated with anorexia and dyspepsia, in patients with PD.

METHODS

Patients were randomly assigned to either Group A (4-week treatment period with 7.5 g/d RKT followed by a 4-week off-treatment period) or Group B (4-week off-treatment period followed by a 4-week treatment period with 7.5 g/d RKT). Appetite, quality of life for gastrointestinal symptoms, and depression were assessed using a visual analog scale, the Gastrointestinal Symptom Rating Scale and the Self-Rating Depression Scale, respectively. The gastric emptying examination and assay of plasma acylated ghrelin level were performed using the ¹³C-acetate breath test and commercially available assay kits, respectively.

RESULTS

RKT treatment produced a significant increase in the appetite score (1.84 [2.34]; P < 0.05), compared to a decrease in the score over the off-treatment period (-1.36 [2.94]). The mean score for abdominal pain, on the Gastrointestinal Symptom Rating Scale, and for self-reported depression, on the Self-Rating Depression Scale, also decreased significantly with RKT treatment (P < 0.05), compared with the off-treatment period scores. No effect of RKT on plasma acylated ghrelin level and rate of gastric emptying was identified.

CONCLUSIONS

RKT may improve anorexia in patients with PD. The positive effects of RKT on depression and anorexia may improve the overall quality of life of these patients. The benefits of RKT identified in our pilot study will need to be confirmed in a randomized, double-blind, controlled trial. UMIN Clinical Trial Registry identifier: UMIN000009626.

Effects of a Herbal Medicine, Yukgunja-Tang, on Functional Dyspepsia Patients Classified by 3-Dimensional Facial Measurement: A Study Protocol for Placebo-Controlled, Double-Blind, Randomized Trial

Introduction. Functional dyspepsia (FD), a common upper gastrointestinal disease, is difficult to manage because of the limitations of current conventional treatments. Yukgunja-tang (YGJT) is widely used to treat FD in clinical practice in Korea, Japan, and China. However, YGJT significantly improves few symptoms of FD. In Korean medicine, FD is a well-known functional gastric disease that shows difference in the effect of herbal medicine depending on constitution or type of Korean medicine diagnosis. This study aims to investigate the efficacy of YGJT on FD patients classified by 3-dimensional facial measurement using a 3-dimensional facial shape diagnostic system (3-FSDS). Methods. A placebo-controlled, double-blind, randomized, two-center trial will be performed to evaluate the efficacy of YGJT on FD patients. Eligible subjects will be initially classified as two types by 3-dimensional facial measurement using the 3-FSDS. Ninety-six subjects (48 subjects per each type) will be enrolled. These subjects will be randomly allocated into treatment or control groups in a 2 : 1 ratio. YGJT or placebo will be administered to each group during the 8-week treatment period. The primary outcome is total dyspepsia symptom scale, and the secondary outcomes include single dyspepsia symptom scale, proportion of responders with adequate symptom relief, visual analog scale, Nepean dyspepsia index-Korean version, functional dyspepsia-related quality of life, and spleen qi deficiency questionnaire. Discussion. This is the first randomized controlled trial to assess the efficacy of the YGJT on FD patients classified by 3-dimensional facial measurement. We will compare the treatment effect of the YGJT on FD patients classified as two types using the 3-FSDS. The results of this trial will help the FD patients improve the symptoms and quality of life effectively and provide objective evidence for prescribing the YGJT to FD patients in clinical practice. Trial Registration. This trial is registered with Clinical Research Information Service Identifier: KCT0001920, 15 May, 2016.

Health-promoting effects of the citrus flavanone hesperidin

Hesperidin, a member of the flavanone group of flavonoids, can be isolated in large amounts from the rinds of some citrus species. Considering the wide range of pharmacological activities and widespread application of hesperidin, this paper reviews preclinical and clinical trials of hesperidin and its related compounds, including their occurrence, pharmacokinetics, and some marketed products available. Preclinical studies and clinical trials demonstrated therapeutical effects of hesperidin and its aglycone hesperetin in various diseases, such as neurological disorders, psychiatric disorders, and cardiovascular diseases and others, due to its anti-inflammatory, antioxidant, lipid-lowering, and insulin-sensitizing properties.

Rikkunshito induces gastric relaxation via the β-adrenergic pathway in Suncus murinus

BACKGROUND

Rikkunshito (RKT) is a gastroprotective herbal medicine. In this study, we investigated the role of RKT in the relaxation of the gastric body (fundus and corpus) and antrum.

METHODS

We used Suncus murinus, a unique small model animal with similar gastrointestinal motility to humans and dogs. RKT was added at 0.1, 1.0, and 5.0 mg/mL to induce relaxation in vitro; the outcome measure was the intensity of relaxation. The number of spontaneous antral contractions in the absence or the presence of RKT was also counted.

KEY RESULTS

Rikkunshito induced the relaxation of the gastric body and antrum and decreased the number of spontaneous antral contractions in a dose-dependent manner. The responses to RKT (1.0 mg/mL) were not affected by pretreatment with atropine, N-nitro-l-arginine methyl ester, ritanserin, or ondansetron. On the other hand, timolol almost completely reversed the relaxation induced by RKT (1.0 mg/mL) on the gastric body and antrum and the occurrence of the spontaneous antral contractions. Both butoxamine, a β(2) -adrenoreceptor antagonist, and L 748337, a β(3) -adrenoreceptor antagonist, but not CGP 20712, a β(1) -adrenoreceptor antagonist, significantly reversed the RKT-induced (1.0 mg/mL) gastric relaxation.

CONCLUSIONS & INFERENCES

These results indicate that RKT stimulates and modulates gastric relaxation through β(2) - and β(3) -adrenergic, but not β(1) -adrenergic, pathways in S. murinus.

A New Strategy Using Rikkunshito to Treat Anorexia and Gastrointestinal Dysfunction

Because the clinical condition of gastrointestinal dysfunction, including functional dyspepsia, involves tangled combinations of pathologies, there are some cases of insufficient curative efficacy. Thus, traditional herbal medicines (Kampo medicines) uniquely developed in Japan are thought to contribute to medical treatment for upper gastrointestinal symptoms. Rikkunshito is a Kampo medicine often used to treat dyspeptic symptoms. Over the past few years, several studies have investigated the efficacy of rikkunshito for dysmotility, for example, upper abdominal complaints, in animals and humans. Rikkunshito ameliorated the decrease in gastric motility and anorexia in cisplatin-treated rats, stress-loaded mice, and selective serotonin reuptake inhibitor-treated rats by enhancing plasma ghrelin levels via serotonin2B/2C receptor antagonism. In addition, rikkunshito ameliorated the decrease in food intake in aged mice and stress-loaded decreased gastric motility via enhanced ghrelin receptor signaling. Several clinical studies revealed that rikkunshito was effective in ameliorating upper gastrointestinal symptoms, including dyspepsia, epigastric pain, and postprandial fullness. In this review, we discuss these studies and propose additional evidence-based research that may promote the clinical use of Kampo medicines, particularly rikkunshito, for treating anorexia and gastrointestinal dysfunction.

Clinical application of kampo medicine (rikkunshito) for common and/or intractable symptoms of the gastrointestinal tract

Gastroenterological reflux disease and functional dyspepsia are usually treatable using Western medical practices. Nonetheless, some cases present with intractable symptoms that are not amenable to these therapies. Treatment with kampo, a traditional Japanese medicine, recently has been proposed as an alternative therapy for use in combination with the Western practices. In general, traditional Japanese medicines have been used empirically for intractable symptoms correctively designated as “general malaises.” Accumulating lines of evidence, including basic and clinical researches, have demonstrate detailed mechanisms where traditional Japanese medicines exert pharmacological action to improve symptoms. Therefore, traditional Japanese medicines have been gaining use by various medical doctors as the specific modes of pharmacological action are recognized. This review covers both the pharmacological functions and the clinical efficacies of rikkunshito for use in treating disorders of the gastrointestinal tract.

A randomized, placebo-controlled, double-blind clinical trial of rikkunshito for patients with non-erosive reflux disease refractory to proton-pump inhibitor: the G-PRIDE study

BACKGROUND

The aim of this study was to investigate the efficacy of rikkunshito (RKT), a traditional Japanese medicine, combined with proton pump inhibitor (PPI) in patients with PPI-refractory non-erosive reflux disease (NERD).

METHODS

Patients with PPI-refractory NERD (n = 242) were randomly assigned to the RKT group [rabeprazole (10 mg/day) + RKT (7.5 g/t.i.d.) for 8 weeks] or the placebo group (rabeprazole + placebo). After the 4- and 8-week treatments, we assessed symptoms and quality of life (QOL) using the Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (FSSG), Gastrointestinal Symptom Rating Scale (GSRS), and Short-Form Health Survey-8 (SF-8).

RESULTS

There were no significant differences in FSSG and GSRS score improvement between these groups after the 4- and 8-week treatments. The mental component summary (MCS) scores of the SF-8 improved more in the RKT group (from 45.8 ± 8.1 to 48.5 ± 7.4) than in the placebo group (from 47.7 ± 7.1 to 48.4 ± 7.5) after the 4-week treatment (P < 0.05). The 8-week treatment with RKT was more effective for improvement of the degree of MCS score in patients with a low body mass index (<22) (P < 0.05) and significantly improved the acid-related dysmotility symptoms of FSSG in female and elderly patients (≥ 65 years).

CONCLUSION

There were no significant differences in improvement of GERD symptoms in patients with PPI-refractory NERD between these groups. However, RKT may be useful for improving mental QOL in non-obese patients and acid-related dyspeptic symptoms, especially in women and the elderly.

Enhancement of catecholamine release from PC12 cells by the traditional Japanese medicine, rikkunshito

BACKGROUND

Rikkunshito is a traditional Japanese herbal medicine that is used to treat appetite loss associated with cancer and other disorders. The formulation contains various constituents that influence cell signaling, and rikkunshito may accordingly affect human homeostasis through multiple regulatory pathways, including those governed by the endocrine system. We investigated the actions of rikkunshito on catecholamine release from PC12 cells, an adrenal chromaffin cell line.

METHODS

The actions of rikkunshito on PC12 cells were evaluated by measuring intracellular cAMP levels, tyrosine hydroxylase (TH) and vasoactive intestinal peptide (VIP) mRNA expression levels, and catecholamine levels in the culture medium. The transcriptional activation of VIP gene by rikkunshito was assessed by using a VIP promoter-driven reporter gene assay.

RESULTS

Rikkunshito dose-dependently enhanced forskolin-induced elevations in cAMP in PC12 cells, and also increased the gene expression of TH and VIP. The transcriptional activation of VIP gene by rikkunshito was confirmed. Norepinephrine and dopamine secretion into the culture medium of PC12 cells were also dose-dependently augmented by rikkunshito and/or forskolin, but experiments with a protein kinase C (PKC) activator and a phosphodiesterase inhibitor revealed that the effects of rikkunshito were not simply due to the modulation of PKC or phosphodiesterase activity.

CONCLUSIONS

These findings suggest that rikkunshito enhances the release of catecholamines by a novel mechanism involving cAMP.

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

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

Randomized clinical trial: rikkunshito in the treatment of functional dyspepsia--a multicenter, double-blind, randomized, placebo-controlled study

BACKGROUND

Rikkunshito, a standardized Japanese herbal medicine, is thought to accelerate gastric emptying and relieve dyspepsia, although no large-scale, randomized, placebo-controlled trials of rikkunshito have been conducted. This study aimed to determine the efficacy and safety of rikkunshito for treating functional dyspepsia (FD).

METHODS

FD patients received 2.5 g rikkunshito or placebo three times a day for 8 weeks in this multicenter, randomized, placebo-controlled, parallel-group trial. The primary end point was the proportion of responders at 8 weeks after starting test drug, determined by global patient assessment (GPA). The improvement in four major dyspepsia symptoms severity scale was also evaluated. In addition, plasma ghrelin levels were investigated before and after treatment.

KEY RESULTS

Two hundred forty-seven patients were randomly assigned. In the eighth week, the rikkunshito group had more GPA responders (33.6%) than the placebo (23.8%), although this did not reach statistical significance (p = 0.09). Epigastric pain was significantly improved (p = 0.04) and postprandial fullness tended to improve (p = 0.06) in the rikkunshito group at week 8. Rikkunshito was relatively more effective among Helicobacter pylori-infected participants (rikkunshito: 40.0% vs placebo: 20.5%, p = 0.07), and seemed less effective among H. pylori-uninfected participants (rikkunshito: 29.3% vs placebo: 25.6%, p = 0.72). Among H. pylori-positive individuals, acyl ghrelin levels were improved just in rikkunshito group. There were no severe adverse events in both groups.

CONCLUSIONS & INFERENCES

Administration of rikkunshito for 8 weeks reduced dyspepsia, particularly symptoms of epigastric pain and postprandial fullness. (UMIN Clinical Trials Registry, Number UMIN000003954).

Administration of exogenous acylated ghrelin or rikkunshito, an endogenous ghrelin enhancer, improves the decrease in postprandial gastric motility in an acute restraint stress mouse model

BACKGROUND

Physical or psychological stress causes functional disorders in the upper gastrointestinal tract. This study aims to elucidate the ameliorating effect of exogenous acylated ghrelin or rikkunshito, a Kampo medicine which acts as a ghrelin enhancer, on gastric dysfunction during acute restraint stress in mice.

METHODS

Fasted and postprandial motor function of the gastric antrum was wirelessly measured using a strain gauge force transducer and solid gastric emptying was detected in mice exposed to restraint stress. Plasma corticosterone and ghrelin levels were also measured. To clarify the role of ghrelin on gastrointestinal dysfunction in mice exposed to stress, exogenous acylated ghrelin or rikkunshito was administered, then the mice were subjected to restraint stress.

KEY RESULTS

Mice exposed to restraint stress for 60 min exhibited delayed gastric emptying and increased plasma corticosterone levels. Gastric motility was decreased in mice exposed to restraint stress in both fasting and postprandial states. Restraint stress did not cause any change in plasma acylated ghrelin levels, but it significantly increased the plasma des-acyl ghrelin levels. Administration of acylated ghrelin or rikkunshito improved the restraint stress-induced delayed gastric emptying and decreased antral motility. Ameliorating effects of rikkunshito on stress-induced gastric dysfunction were abolished by simultaneous administration of a ghrelin receptor antagonist.

CONCLUSIONS & INFERENCES

Plasma acylated/des-acyl ghrelin imbalance was observed in acute restraint stress. Supplementation of exogenous acylated ghrelin or enhancement of endogenous ghrelin signaling may be useful in the treatment of decreased gastric function caused by stress.

Beneficial effects of rikkunshito, a Japanese kampo medicine, on gastrointestinal dysfunction and anorexia in combination with Western drug: a systematic review

Background. Kampo medicines are traditional herbal medicines which have been approved for medicinal use by the Japanese Ministry of Health and Welfare and are currently being used more and more, often in combination with Western drugs. Thus, the need for investigation of interactions between Kampo medicines and Western drugs is now widely recognized. Aim. To summarize the effects and drug interactions of rikkunshito, a Kampo medicine often prescribed for upper gastrointestinal disorders and anorexia. Methods. Animal and human studies were systematically reviewed to identify published data on rikkunshito. Results describing its effects were abstracted, with an emphasis on drug interactions. Results and Discussion. Rikkunshito ameliorates anorexia induced by anticancer drugs, improves quality of life scores, and can even prolong survival compared with monotherapy. Rikkunshito combined with proton pump inhibitor therapy is shown to be useful in the treatment of PPI-refractory gastroesophageal reflux disease patients and patients with gastrointestinal symptoms after endoscopic submucosal dissection. Rikkunshito reduces antidepressant-induced adverse events and improves quality of life without influencing antidepressant effects. Conclusions. Rikkunshito shows ameliorative effects on adverse reactions induced by various Western drugs and can achieve better results (e.g., anticancer drugs and proton pump inhibitor) without influencing the efficacy and bioavailability of Western drugs.

Effects of Kampo on functional gastrointestinal disorders

This article reviews the effectiveness of Kampo (traditional Japanese herbal medicine) in the treatment of functional gastrointestinal disorders, especially functional dyspepsia (FD) and irritable bowel syndrome (IBS). The results of four randomized, controlled trials (RCTs) suggested the usefulness of rikkunshito in relieving the subjective symptoms of patients with FD. Rikkunshito significantly improved not only gastric symptoms, such as epigastiric discomfort, but also extra-gastric symptoms, such as general fatigue, when compared with control drugs. The therapeutic effects of rikkunshito were more evident when it was prescribed to patients with “kyosho”, i.e., low energy. Two RCTs suggested the efficacy of keishikashakuyakuto for IBS.

Basic research studies have demonstrated that these Kampo medicines have multiple sites of action to improve subjective symptoms. For example, rikkunshito improves gastric motility dysfunction, including impaired adaptive relaxation and delayed gastric emptying, gastric hypersensitivity, and anorexia via facilitation of ghrelin secretion. It also exhibits anti-stress effects, i.e., it attenuates stress-induced exacerbation of gastric sensation and anorexia, as well as the hypothalamic-pituitary-adrenocortical axis and sympathetic activation. Keishikashakuyakuto exhibited not only an antispasmodic effect on intestinal smooth muscle, but also antidepressant-like effects. Case series suggest that other Kampo prescriptions are also effective for FD and IBS. However, further studies are necessary to evaluate their efficacy.

Dietary herb extract rikkunshi-to ameliorates gastroparesis in Parkinson's disease: a pilot study

OBJECTIVE

To perform an open trial on the effects of the extract of the dietary herb Rikkunshi-to (RKT) on gastroparesis in Parkinson's disease (PD) patients, using objective parameters given by the (13)C-sodium acetate expiration breath test (gastric emptying study).

METHODS

Twenty patients with PD were enrolled into this study. Eleven patients were male and 9 were female, with the following characteristics (mean ± SD): age, 69.4 ± 8.17 years; disease duration, 4.34 ± 4.03 years; modified Hoehn and Yahr stage, 2.37 ± 0.98, and Unified Parkinson's Disease Rating Scale Part 3 motor score, 16.6 ± 7.37. Fourteen patients came to the clinic due to constipation; 16 patients were taking 288 ± 72 mg/day levodopa/carbidopa, 2 were taking dopamine agonists, and the others were not treated yet. All patients underwent the breath test. Statistical analysis was performed using Student's t test.

RESULTS

RKT was well tolerated by all patients and none experienced abdominal pain or other adverse effects, except for its bitter taste. RKT significantly reduced the peak time of the (13)C-dose-excess curve (p < 0.05).

CONCLUSION

In this pilot trial, we found a significant shortening of the gastric emptying time after administration of the dietary herb extract RKT in PD patients. Further studies examining both gastric emptying and delayed-on in PD are warranted. .

Kampo medicines for gastrointestinal tract disorders: a review of basic science and clinical evidence and their future application

Treatment with kampo, the Japanese traditional medicine, is a form of pharmacological therapy that combines modern Western and traditional Asian medical practices. In Japan, various traditional medicines are often combined with Western medicines and prescribed for patients with diseases such as gastroesophageal reflux disease, functional dyspepsia, chronic gastritis, irritable bowel syndrome, and post-operative ileus. Based on numerous past observations, Japanese traditional medicines are thought to be particularly useful in the treatment of medically unexplained physical symptoms such as nausea, abdominal discomfort, and anorexia. However, the detailed mechanism by which they mediate their pharmacological action is yet unknown. In addition, the clinical evidence to support their use is insufficient. This review focuses on the basic evidence of the pharmacological action and the clinical efficacies of kampo medicines accumulated over several past decades. In addition, we introduce both the current novel insights into kampo medicines and the therapeutic approach employed when they are used to treat various disorders of the gastrointestinal tract.

Functional dyspepsia

PURPOSE OF REVIEW

This review summarizes the recent progress in the epidemiology, pathophysiology and treatment of functional dyspepsia.

RECENT FINDINGS

Epidemiological, pathophysiological and therapeutic studies continue to examine the Rome III-proposed subdivision of functional dyspepsia into epigastric pain syndrome and postprandial distress syndrome. Although epidemiological studies support the subdivision, studies in patient samples show major overlap. Several studies identified overlapping functional disorders and psychosocial comorbidity as major contributors to the severity of functional dyspepsia and its impact on quality of life. Central processing of visceral stimuli, and its role in the pathogenesis of functional dyspepsia, as well as low-grade inflammation in the duodenum are important emerging topics in pathophysiology research. Therapeutic studies have reported on prokinetic and fundus-relaxing drugs. Acotiamide is a first-in-class drug with both prokinetic and fundus-relaxing properties that was evaluated in the recent phase 2 and phase 3 trials in functional dyspepsia.

SUMMARY

There is gradual progress in our understanding of the symptom pattern, impact and pathophysiology of functional dyspepsia. The areas of recent advances including the recognition of low-grade duodenal inflammation, central nervous system processing and the exploration of novel pharmacotherapeutic approaches are summarized in this review.