The Chinese herbal formula Huoxiang Zhengqi for diarrhea-predominant irritable bowel syndrome (CHAIRS): a study protocol for a double-blinded randomized controlled trial

Modified Gwakjeongtang for Diarrhea-Predominant Irritable Bowel Syndrome: Study Protocol for a Randomized, Double-Blind, Placebo-Controlled, Pilot Clinical Trial

Introduction

Irritable bowel syndrome (IBS) is a chronic condition characterized by recurrent abdominal pain associated with bowel movements. Modified Gwakjeongtang (MGT), an herbal prescription rooted in traditional East Asian medicine, consists of thirteen botanical drugs known for their potential to enhance intestinal barrier function, regulate gastrointestinal motility, and exhibit anti-inflammatory and antioxidant properties. Despite a few previous clinical trials highlighting MGT's potential for IBS symptom management, limited evidence exists with placebo control.

Methods and Analysis

In this pilot randomized clinical trial protocol, we aim to exploratively evaluate the efficacy and safety of MGT in patients with diarrhea-predominant IBS (IBS-D) by comparing it with a placebo. A total of 60 IBS-D patients will be enrolled, and eligible participants will be randomly allocated to either the MGT or placebo groups. Over a 4-week period, they will receive MGT or placebo granules three times a day. The primary endpoint will be the overall response rate post-treatment, determined through daily assessments of abdominal pain intensity and stool consistency.

Ethics and Dissemination

This clinical trial protocol has received approval from the Korean Ministry of Food and Drug Safety for an investigational new drug application and Institutional Review Board of the Kyung Hee University Korean Medicine Hospital. The research findings will be submitted and published in international peer-reviewed journal.

Trial Registration

Clinical research information service (registration number: KCT0008523).

Protective effects of Liupao tea against high-fat diet/cold exposure-induced irritable bowel syndrome in rats

Liupao tea as a type of dark tea can relieve irritable bowel syndrome by regulating gut microbiota, but the mechanism has not been fully explained. An ultra-high performance liquid chromatography along with quadrupole time of flight tandem mass spectrometry was used to analyze the phytochemicals in Liupao tea. Then, we explored the effects of Liupao tea against IBS. From the results of chemical analysis, we identified catechins, polyphenols, amino acids, caffeine, polysaccharides and other components in Liupao tea. The open-field test, gastrointestinal function-related indexes, histochemical assays, measurements of cytokine and aquaporin 3 (AQP3), and determination of serum metabolites were utilized to monitor the physiological consequences of Liupao tea administration in rats with irritable bowel syndrome. The results showed that Liupao tea had a significant protective effect on irritable bowel syndrome. Liupao tea increased locomotive velocity while reducing interleukin-6, interleukin-1β, and tumor necrosis factor-α levels, as well as gastrointestinal injury. Moreover, Liupao tea increased the AQP3 levels of renal tissues but reduced the AQP3 levels of gastrointestinal tissues. Liupao tea reduced the Firmicutes/Bacteroides ratio and significantly reconstructed the microbial pattern. Liupao tea relieved irritable bowel syndrome by repairing gastrointestinal dysfunction, regulating the secretion of pro-inflammatory cytokines, modulating water metabolism, and restoring microbial homeostasis.

Magnolol and honokiol target TRPC4 to regulate extracellular calcium influx and relax intestinal smooth muscle

ETHNOPHARMACOLOGICAL RELEVANCE

Magnolia officinalis Cortex (M. officinalis) is a classical traditional Chinese medicine (TCM) widely used to treat digestive system diseases. It effectively regulates gastrointestinal motility to improve abdominal pain, abdominal distension and other symptoms. Magnolol (MAG) and honokiol (HON) are the main pharmacodynamic components responsible for the gastrointestinal activity of M. officinalis.

AIM OF THE STUDY

The transient receptor potential (TRP) family is highly expressed in the gastrointestinal tract and participates in the regulation of gastrointestinal motility, visceral hypersensitivity, visceral secretion and other physiological activities. In this study, the calcium-lowering mechanisms of MAG and HON contributing to the smooth muscle relaxation associated with TRP are discussed.

MATERIALS AND METHODS

The relaxation smooth muscle effects of MAG and HON were tested by the isolated intestine tone tests. A synthetic MAG probe (MAG-P) was used to target fishing for their possible target. The distribution of MAG on the smooth muscle was identified by a molecular tracer based on chemical biology. Ca²⁺ imaging and dual-luciferase reporter assays were used to determine the effects on the target proteins. Finally, the calcium-mediating effects of MAG and HON on smooth muscle cells and TRPC4-knockdown cells were compared to verify the potential mechanism.

RESULTS

After confirming the smooth muscle relaxation in the small intestine induced by MAG and HON, the relaxation effect was identified mainly due to the downregulation of intracellular calcium by controlling external calcium influx. Although MAG and HON inhibited both TRPV4 and TRPC4 channels to reduce calcium levels, the inhibitory effect on TRPC4 channels is an important mechanism of their smooth muscle relaxation effect, since TRPC4 is widely expressed in the small intestinal smooth muscle cells.

CONCLUSIONS

The inhibition of MAG and HON on TRPC4 channels contributes to the relaxation of intestinal smooth muscle.

Chinese Herbal Formula Huoxiang Zhengqi for Dampness Pattern in Atopic Dermatitis and Diarrhea-Predominant Irritable Bowel Syndrome: Rationale and Design of a Master Protocol

Introduction. Atopic dermatitis (AD) and diarrhea-predominant irritable bowel syndrome (IBS-D) are two recurrent diseases with limited effective treatments. In Chinese Medicine (CM) theory, they may share dampness pattern as the same dominant pathogenesis at a certain stage and, thus, can be treated with the same method. While Chinese herbal formula Huoxiang Zhengqi (HXZQ) has been reported as an effective dampness-resolving therapy for both AD and IBS-D, further high-quality clinical studies are still needed. In addition, HXZQ lacks accurate clinical positioning based on CM patterns. Therefore, we utilize a master protocol design to evaluate HXZQ for dampness pattern simultaneously in AD and IBS-D, with the aim of identifying the pattern-defined population of HXZQ. Methods and Analysis. This master protocol design includes two randomized controlled trials (RCTs) and a real-world observational study. Based on two registry cohorts of AD and IBS-D, patients with dampness pattern will be enrolled in the RCTs to receive either HXZQ oral liquid or a placebo for 4 weeks and then will be followed up for another 4 weeks, while patients with nondampness pattern will constitute the observational study and experience a 12-week follow-up. A total of 678 AD patients and 322 IBS-D patients will be recruited from 14 hospitals in China over a 3-year period. The eczema area and severity index (EASI) and the proportion of responders for adequate relief (AR) are the primary outcomes in AD and IBS-D, respectively. Analysis will be undertaken separately in each substudy, and then an overall analysis combining multiple subgroups will be performed to comprehensively investigate the effect of HXZQ. Discussion. This study will provide high-quality efficacy evidence of HXZQ for AD and IBS-D patients and give an example of postmarketing evaluation for CM products under the pattern dominating different disease research model. The study is registered with ChiCTR1900026700 and ChiCTR1900026837.