Moxibustion ameliorates visceral hypersensitivity by regulating hypothalamus-spinal cord-colon axis in rats with irritable bowel syndrome with diarrhea

OBJECTIVES

To observe the effect of moxibustion intervention on the hypothalamus-spinal cord-colon axis of rats with irritable bowel syndrome with diarrhea (IBS-D) and explore the mechanism of moxibustion in improving visceral hypersensitivity in rats with IBS-D.

METHODS

A total of 36 SD rats were randomly divided into normal, model, and moxibustion groups, with 12 rats in each group. The IBS-D model was established by maternal separation + acetic acid stimulation + chronic restraint. Rats of the moxibustion group received bilateral moxibustion on "Tianshu" (ST25) and "Shangjuxu" (ST37) for 15 min, once a day for 7 consecutive days. The body weight, loose stool rate, and minimum threshold volume of abdominal withdrawal reflex (AWR) were measured before and after moxibustion intervention, respectively. The histopathological changes in the colon tissue were observed after HE staining. The number of colonic mucosal mast cells (MCs) was measured by toluidine blue staining. The activation of MCs was determined by tryptase positive expression level and examined by immunohistochemical staining. The content, protein and mRNA expression levels and positive expression levels of corticotropin releasing factor (CRF), substance P (SP), and calcitonin gene-related peptide (CGRP) in the hypothalamus, spinal cord and colon tissues were measured by ELISA, Western blot, real-time fluorescent quantitative PCR and immunofluorescence staining, respectively.

RESULTS

Compared with the normal group, the loose stool rate was increased (P<0.01)；the body weight and minimum threshold volume of AWR were decreased (P<0.01)；the inflammatory infiltration of colon tissues was obvious；the number of MCs and positive expression level of tryptase in the colon tissue were increased (P<0.01)；the contents, positive expression le-vels, protein and mRNA expression levels of CRF, SP and CGRP in the hypothalamus, spinal cord and colon tissues were increased (P<0.01, P<0.05) in the model group. After the intervention, compared with the model group, all these indicators showed opposite trends (P<0.01, P<0.05) in the moxibustion group.

CONCLUSIONS

Moxibustion can improve visceral hypersensitivity in rats with IBS-D, and its mechanism may be related to regulating the hypothalamic-spinal-colon axis to reduce the release of CRF, SP and CGRP, and thus to inhibite MC in colon tissue.

Cognition of abdominal pain and abdominal discomfort in Chinese patients with irritable bowel syndrome with diarrhea

BACKGROUND

In Asia, the proportion of patients with irritable bowel syndrome (IBS) with abdominal discomfort alone is significantly higher than that in western countries. The purposes of this study are to understand the cognition of abdominal pain and abdominal discomfort in Chinese patients with IBS and to compare the clinical characteristics of patients with abdominal pain alone and with abdominal discomfort alone.

METHODS

Patients with IBS with diarrhea (IBS-D) who met the Rome III diagnostic criteria and had episodes of at least one day/week were consecutively enrolled. The cognition of abdominal pain and abdominal discomfort were investigated through face-to-face unstructured interview. Patients were divided into a pain group and a discomfort group according to the cognition interviews, then the characteristics and severity of symptoms (IBS symptom severity scale, IBS-SSS), IBS quality of life (IBS-QOL) and psychological state were compared between groups.

RESULTS

A total of 88 patients with IBS-D were enrolled. Most of the patients with self-reported abdominal pain described their pain as spasm/cramping; patients with self-reported abdominal discomfort had as many as 24 different descriptions of discomfort. Most patients having abdominal pain and discomfort could accurately distinguish the two symptoms. The degree of abdominal pain in the pain group was higher than abdominal discomfort in the discomfort group (P = 0.002). There was no significant difference in IBS-SSS, extra-intestinal pain, IBS-QOL, and psychological state between the two groups.

CONCLUSIONS

For Chinese patients with IBS-D, abdominal pain and abdominal discomfort are two different symptoms, but they have similar clinical features.

TRIAL REGISTRATION

ChiCTR, ChiCTR1900028082. Registered 11 December 2019 - Retrospectively registered, http://www.chictr.org.cn .

ROS-responsive thioketal-linked alginate/chitosan carriers for irritable bowel syndrome with diarrhea therapy

A colon-specific carrier that can protect drugs from the destruction in the gastrointestinal tract is critical for treating irritable bowel syndrome with diarrhea (IBS-D). In this study, chitosan was cross-linked by the thioketal (TK) bond to serve as a ROS-sensitive core of microspheres. Then the chitosan core was coated with an alginate shell. The alginate/chitosan microspheres can protect puerarin against the destruction and elimination in the gastrointestinal tract and release puerarin at the lesion sites in large quantities. The microspheres were characterized using differential scanning calorimetry, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The swelling study showed that microspheres would shrink in an acidic environment. The in vitro release analysis indicated that little puerarin was released at gastric pH but burst release was observed in simulated colonic fluid containing H₂O₂. Fluorescent tracer revealed that the fluorescence of microspheres lasted up to 30 h in the colon, which was beneficial to prolong the action time between puerarin and colon. The in vivo studies indicated that puerarin-loaded microspheres are more effective in the treatment of IBS-D than free puerarin. Altogether, the ROS-responsive alginate/chitosan microspheres may be a promising strategy for IBS-D.

Ramosetron for the treatment of irritable bowel syndrome with diarrhea: a systematic review and meta-analysis of randomized controlled trials

Background

Ramosetron is a potent and selective serotonin type 3 receptor antagonist. This meta-analysis aimed to analyze the efficacy and safety of ramosetron for irritable bowel syndrome with diarrhea (IBS-D).

Methods

Pubmed, MEDLINE, EMBASE and the Cochrane Library were searched for randomized controlled trials investigating the efficacy and safety of ramosetron for IBS-D. Risk of bias was assessed as described in the Cochrane handbook. A random effects model was used to calculate the effects of ramosetron vs placebo on symptomatic improvements, including relief of overall IBS symptoms, relief of abdominal discomfort/pain, improvement in abnormal bowel habits, and improvement in stool consistency, expressed as pooled relative risks (RRs) with 95% confidence interval (CI). Adverse events data were also summarized with RRs.

Results

Four randomized controlled trials involving 1623 participants were included. Compared with placebo, ramosetron could lead to relief of overall IBS symptoms (RR 1.70; 95%CI 1.48, 1.95), relief of abdominal discomfort/pain (RR 1.41; 95%CI, 1.24, 1.59), improvement in abnormal bowel habits (RR 1.72; 95%CI, 1.50, 1.98) and improvement in stool consistency (RR 1.71; 95%CI 1.40, 2.08). Ramosetron could lead to relief of overall IBS symptoms in both male and female patients (RR; 95%CI: 1.94; 1.58, 2.38 and 1.49; 1.25, 1.79). The RR (95%CI) for reported adverse events of ramosetron vs placebo was 1.10 (0.97, 1.26) across all studies. No serious adverse events (e.g., ischemic colitis) were reported. The incidences of hard stool and constipation were higher in ramosetron group compared with placebo group (RR; 95%CI: 4.74; 3.00, 7.51 and 2.53; 1.57, 4.10, respectively).

Conclusions

Ramosetron had beneficial effects to both male and female IBS-D patients. Treatment with ramosetron could cause more hard stool and constipation, without severe adverse events.

Economic burden of inadequate symptom control among US commercially insured patients with irritable bowel syndrome with diarrhea

AIMS

To assess healthcare resource use and costs among irritable bowel syndrome (IBS) with diarrhea (IBS-D) patients with and without evidence of inadequate symptom control on current prescription therapies and estimate incremental all-cause costs associated with inadequate symptom control.

METHODS

IBS-D patients aged ≥18 years with ≥1 medical claim for IBS (ICD-9-CM 564.1x) and either ≥2 claims for diarrhea (ICD-9-CM 787.91, 564.5x), ≥1 claim for diarrhea plus ≥1 claim for abdominal pain (ICD-9-CM 789.0x), or ≥1 claim for diarrhea plus ≥1 pharmacy claim for a symptom-related prescription within 1 year of an IBS diagnosis were identified from the Truven Health MarketScan database. Inadequate symptom control, resource use, and costs were assessed up to 1 year following the index date. Inadequate symptom control included any of the following: (1) switch or (2) addition of new symptom-related therapy; (3) IBS-D-related inpatient or emergency room (ER) admission; (4) IBS-D-related medical procedure; (5) diagnosis of condition indicating treatment failure; or (6) use of a more aggressive prescription. Generalized linear models assessed incremental costs of inadequate symptom control.

RESULTS

Of 20,624 IBS-D patients (mean age = 48.5 years; 77.8% female), 66.4% had evidence of inadequate symptom control. Compared to those without inadequate symptom control, patients with evidence of inadequate symptom control had significantly more hospitalizations (12.0% vs 6.0%), ER visits (37.1% vs 22.6%), use of outpatient services (73.0% vs 60.7%), physician office visits (mean 11.0 vs 8.1), and prescription fills (mean 40.0 vs 26.7) annually (all p < .01). Incremental costs associated with inadequate symptom control were $3,065 (2013 US dollars), and were driven by medical service costs ($2,391; 78%).

LIMITATIONS

Study included US commercially insured patients only and inferred IBS-D status and inadequate symptom control from claims.

CONCLUSIONS

Inadequate symptom control associated with available IBS-D therapies represents a significant economic burden for both payers and IBS-D patients.

Health-related quality of life, work productivity, and indirect costs among patients with irritable bowel syndrome with diarrhea

Background

Irritable bowel syndrome (IBS) affects 10–15% of adults in the US, and is associated with significant impairment in health-related quality of life (HRQoL); however, information specific to the diarrhea subtype (IBS-D) is lacking. We assessed the impact of IBS-D on HRQoL, work productivity, and daily activities, and the associated indirect costs, among a sample of the US population.

Methods

Respondents (≥18 years) from the 2012 US National Health and Wellness Survey who reported an IBS-D diagnosis by a physician or symptoms consistent with Rome II criteria for IBS-D were identified as having IBS-D. Controls included respondents without IBS-D or inflammatory bowel disease. HRQoL was assessed via the Short Form 36 Health Survey version 2 questionnaire and summarized into Mental and Physical Component Summary (MCS; PCS) scores and a Short Form-6 dimension (SF-6D) utility score. Work and activity impairment were assessed via the Work Productivity and Activity Impairment Questionnaire: General Health version (WPAI:GH), which measures absenteeism, presenteeism, overall work productivity loss, and daily activity impairment. Indirect costs were calculated using unit cost data from the Bureau of Labor Statistics and variables from the WPAI:GH. Generalized linear models were used to examine differences in health outcomes between respondents with IBS-D and controls, controlling for demographic and health characteristics.

Results

In total, 66,491 respondents (1102 IBS-D; 65,389 controls) were analyzed. Mean age was 48.7 years; 50% were female. Compared with controls, the IBS-D cohort reported significantly lower HRQoL (mean MCS: 45.16 vs. 49.48; p < 0.001; mean PCS: 47.29 vs. 50.67; p < 0.001; mean SF-6D: 0.677 vs. 0.741; p < 0.001) and greater absenteeism (5.1% vs. 2.9%; p = 0.004), presenteeism (17.9% vs. 11.3%; p < 0.001), overall work productivity loss (20.7% vs. 13.2%; p < 0.001), and activity impairment (29.6% vs. 18.9%; p < 0.001). Respondents with IBS-D also incurred an estimated $2486 more in indirect costs ($7008 vs. $4522; p < 0.001).

Conclusions

Compared with controls, IBS-D is associated with significantly lower HRQoL, greater impairments in work and daily activities, and higher indirect costs, imposing a substantial burden on patients and employers. These findings suggest a significant unmet need exists for effective IBS-D treatments.

Possible therapeutic role of IgE blockade in irritable bowel syndrome

Omalizumab is a humanized monoclonal antibody that binds to the high-affinity type-I IgE Fc receptors on mast cells (MCs) and basophils, inhibiting the IgE immune pathway. Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder, and dysregulation of the immune system likely contributes to its etiology and/or symptomatology. Colonic biopsies from patients with IBS demonstrate considerable increase in the number of degranulating MCs releasing histamine in proximity to nerves, and this event may underlie the common IBS symptom of abdominal pain. Pharmacologic control of MC activation and mediator release is a current area of active interest in the field of IBS research. Recently, we and Pearson et al described 2 cases of patients with IBS with diarrhea (IBS-D) showing positive clinical response to omalizumab. In both cases, the female patients had severe, long-lasting IBS-D and achieved an almost complete resolution of IBS symptoms. Both patients were also able to discontinue all IBS medications after commencing the anti-IgE therapy. For both patients, the omalizumab treatment showed a relatively rapid onset of action, resembling the efficacy observed in and previously reported for patients with chronic spontaneous urticaria. In this Editorial, we discuss the possible biological mechanisms that may underlie the clinical efficacy of omalizumab in IBS. We suggest that there is a need for a well-designed prospective study to investigate the therapeutic effects of anti-IgE in IBS.

Contents of amino acid neurotransmitters and expression of γ-aminobutyric acid receptor in two subtypes of irritable bowel syndrome

AIM: To explore the feasibility of using in vivo cerebral microdialysis and high performance liquid chromatography (HPLC) to determine the contents of glutamate (Glu), glycine (Gly), γ-aminobutyric acid (γ-GABA) and taurine (Tau), and to observe the protein expression of γ-aminobutyric acid receptor A (GABA_Aα1) in irritable bowel syndrome with diarrhea (IBS-D) and irritable bowel syndrome with constipation (IBS-C) to investigate the preliminary pathogenesis of these two subtypes.

METHODS: Using in vitro relative recovery and in vivo relative loss ratio as monitoring indicators, the feasibility of using cerebral microdialysis and HPLC to determine the contents of Glu, Gly, Tau and γ-GABA was first explored. IBS-C was induced by cold water administration and IBS-D by folium sennae combined with restraint. Cerebral microdialysis and HPLC were then used to determine the contents of Glu, Gly, Tau and γ-GABA in the rat brain. Western blot was used to detect the expression of GABA_Aα1 protein in brain tissue.

RESULTS: In vivo cerebral microdialysis and HPLC were feasible for determining the contents of Glu and γ-GABA; the in vitro relative recovery rates were 21.6% and 24.5%, respectively; in vivo relative loss rates were 41.8% and 32.5%. Compared with rats in the normal group, the ratio of Glu/γ-GABA in the IBS-C and IBS-D groups significantly increased (P < 0.05). GABA_Aα1 protein expression in both IBS-C and IBS-D groups were significantly higher than that in the normal group (P < 0.05). In addition, GABA_Aα1 protein expression in the IBS-D group was significantly higher than that in the IBS-C group (P < 0.05).

CONCLUSION: The pathogenesis of IBS-C and IBS-D may be related with Glu/GABA ratio and GABA_Aα1 in the brain.