Functional Constipation: Individualising Assessment and Treatment

Preclinical pharmacokinetic studies and prediction of human PK profiles for Deg-AZM, a clinical-stage new transgelin agonist

Introduction

Deglycosylated azithromycin (Deg-AZM), a newly developed Class I drug with good therapeutic effects on slow transit constipation, is a small-molecule transgelin agonist that has been approved for clinical trials in 2024. The preclinical pharmacokinetic profile of Deg-AZM was investigated to support further development.

Methods

A LC-MS/MS method was established and validated to detected the concentration of Deg-AZM in various biological samples. In vivo tests such as pharmacokinetic studies in rats and dogs, tissue distribution studies in rats, and extraction studies in rats were conducted to investigated the preclinical pharmacokinetic behaviors of Deg-AZM comprehensively. The plasma protein rate of Deg-AZM was determined by rapid equilibrium dialysis method in vitro. The metabolic stability and metabolite profile of Deg-AZM was assessed using pooled mice, rats, dogs, monkeys and humans microsomes in vitro. The PK profiles of Deg-AZM in human was predicted based on physiologically based pharmacokinetic (PBPK) models.

Results

The plasma protein binding rates of Deg-AZM were lower in mice and rats, higher in dogs, and moderate in humans. The metabolic process of Deg-AZM was similar in rat and human liver microsomes. From Pharmacokinetic studies in rats and dogs, Deg-AZM was rapidly absorbed into the blood and then quickly eliminated. Plasma exposure of Deg-AZM was dose dependent with no accumulation after continuous gavage administration. In addition, there is no significant gender difference in the pharmacokinetic behavior of Deg-AZM. Deg-AZM was widely distributed in the tissues without obvious accumulation, and mainly excreted from the urinary excretion pathway. Furthermore, the pharmacokinetic profiles of Deg-AZM in humans showed dose dependency.

Conclusion

The pharmacokinetic profiles of Deg-AZM was fully explored, these results could provide valuable information to support the first-in-human dosage prediction and phase I clinical design.

Yiqi Kaimi prescription regulates protein phosphorylation to promote intestinal motility in slow transit constipation

ETHNOPHARMACOLOGICAL RELEVANCE

The clinical efficacy of the Yiqi Kaimi prescription has been confirmed in slow transit constipation. However, the effects and biological mechanism of Yiqi Kaimi prescription are still unclear.

AIMS OF THE STUDY

To identify the effects of Yiqi Kaimi prescription on intestinal motility; To reveal the potential key targets and pathways of Yiqi Kaimi prescription for the treatment of slow transit constipation.

MATERIALS AND METHODS

The effects of Yiqi Kaimi prescription on slow transit constipation were investigated in a mouse model. The terminal ink propulsion experiment and fecal indocyanine green imaging was used to measure the intestinal transit time. Protein phosphorylation changes in colon tissues treated with Yiqi Kaimi prescription were detected using a Phospho Explorer antibody microarray. Bioinformatic analyses were performed using the Database for Annotation Visualization and Integrated Discovery (DAVID) and the Search Tool for the Retrieval of Interacting Genes (STRING). Western blot analysis and immunohistochemistry confirmed the observed changes in phosphorylation.

RESULT

s: Yiqi Kaimi prescription significantly increased the intestinal transit rate (P < 0.05 vs. model) and reduced the time to first discharge of feces containing fecal indocyanine green imaging in mice (P < 0.05 vs. model). The administration of Yiqi Kaimi prescription induced phosphorylation changes in 41 proteins, with 9 upregulated proteins and 32 downregulated proteins. Functional classification of the phosphorylated proteins with DAVID revealed that the critical biological processes included tyrosine protein kinases, positive regulation of calcium-mediated signaling and response to muscle stretch. The phosphorylation of the spleen tyrosine kinase (SYK) at Tyr348 increased 2.19-fold, which was the most significant change. The phosphorylation level of the transcription factor p65 (RELA) at Thr505 was decreased 0.57-fold. SYK was a hub protein in the protein-protein interaction network and SYK and RELA formed the core of the secondary subnetwork. The key protein phosphorylation after treatment with Yiqi Kaimi prescription were verified by Western blot analysis and immunohistochemistry.

CONCLUSION

Yiqi Kaimi prescription significantly enhanced intestinal motility. This effect was attributed to alterations in the phosphorylation levels of various target proteins. The observed changes in protein phosphorylation, including SYK and RELA, may serve as crucial factors in the treatment of slow transit constipation.

Structure characterization of polysaccharides from Cistanche deserticola and their neuroprotective effects against oxidative stress in slow transit constipation mice

Oxidative stress-induced enteric neuropathy is an important factor in slow transit constipation (STC). Cistanche deserticola crude polysaccharides (CDCP) are natural antioxidants with various biological activities. We prepared CDCP through water-extract and alcohol-precipitation methods. The structural characteristics of CDCP were analyzed by infrared spectroscopy and methylation analysis. The results showed that CDCP was primarily composed of (1 → 4)-linked glucans with minor amounts of pectic polysaccharides. Different doses of CDCP (100, 200, and 400 mg/kg) were administered to loperamide-induced STC mice to explore the therapeutic effects of CDCP. Compared with the untreated group, CDCP treatment significantly improved constipation symptoms, relevant gut-regulating peptides levels, colonic pathological damage, and colonic myenteric nerons injury. CDCP enhanced the antioxidant capacity by decreasing Malondialdehyde (MDA) content, increasing Superoxide Dismutase (SOD) activity and Reduced Glutathione (GSH) content. CDCP significantly reduced oxidative stress-induced injury by preserving mitochondrial function in the colonic myenteric plexus. Furthermore, the neuroprotective effects of CDCP might be associated with the Nrf2/Keap1 pathway. Thus, our findings first revealed the potential of CDCP to protect the colonic myenteric plexus against oxidative stress-induced damage in STC, establishing CDCP as promising candidates for natural medicine in the clinical management of STC.

Croton tiglium L. seeds ameliorate loperamide-induced constipation via regulating gastrointestinal hormones and gut microbiota before and after processing

ETHNOPHARMACOLOGICAL RELEVANCE

Crotonis Fructus (CF), the seeds of Croton tiglium L., have been commonly used in the treatment of constipation for more than two thousand years in traditional Chinese medicine (TCM). CF needs to be processed before clinical use and Crotonis Semen Pulveratum (CP) is the processed cream of CF, which could reduce the drastic purgative action and gastrointestinal damages. However, the mechanism of CF and CP in the treatment of constipation is still unclear.

AIM OF THE STUDY

This study was to evaluate the effects of CF and CP on loperamide-induced constipation and the underlying mechanism.

MATERIALS AND METHODS

The chemical compositions of CF and CP were analyzed by UPLC-Q-TOF-MS. Constipated mouse model was established by loperamide (9.6 mg/kg, b.w., i.g.) for two weeks. After successful modeling, the mice were treated with CF or CP (45.5 and 136.5 mg/kg, b.w., i.g.) once a day for seven days. The physiological status, defecation indices, defecation time, and intestinal propulsion rate in mice were measured. Histopathologic examination and serum biochemical parameters were further estimated. 16S rDNA gene sequencing was carried out to characterize the effects of CF and CP on intestinal microbiome structure. Spearman correlation analysis was also performed to explore the association between gut microbiotic abundance and serum indices.

RESULTS

The results verified the therapeutic effects of CF and CP on loperamide-induced constipation. CF and CP could significantly ameliorate the reduction of fecal number, fecal weight, fecal water content, and intestinal propulsion rate in mice with constipation, and the first stool defecation time was also obviously reduced. Moreover, CF and CP could regulate the secretion of gastrointestinal hormones and inflammatory factors induced by constipation. Histopathologic examination showed that CP was superior to CF in relieving pathological injury and inflammatory cell infiltration. According to 16S rDNA sequencing, CF and CP treatment could improve gut microbiota disturbance in mice with constipation and the abundance of opportunistic pathogens such as Parabacteroides, Parasutterella and Bacillus remarkably declined, while the levels of beneficial bacterial such as Candidatus_Arthromitus significantly increased. Besides, CP may play a better role in correcting the intestinal flora disorder than CF, which was more obvious in the high-dose group. In addition, phytochemical analysis revealed the presence of diterpenoids and alkaloids in CF and CP.

CONCLUSIONS

CF and CP could ameliorate loperamide-induced constipation by regulating gastrointestinal hormones secretion, reducing the levels of inflammatory cytokines and improving the disturbance of gut microbiota. Moreover, CP was superior to CF in the enrichment of beneficial bacteria and reduction of harmful bacteria and histopathological damage induced by constipation, which may be related to the changes in the species and content of diterpenoids after processing. The study provides new evidence for the processing mechanism and clinical application of CF and CP.

Risk Factor Analysis and Intervention Study for Unspecific Functional Enteropathy in a Maritime Environment: A Cross-Sectional Analytical Survey

Background

The study aimed to investigate the risk factors and interventions for unspecific functional bowel disorders (U-FBDs) in military personnel under maritime environment.

Methods

This cross-sectional analytical survey used the Rome III questionnaire for surveying 1018 military personnel involved in overseas humanitarian medical services from June 2013 to January 2016. Individuals diagnosed with U-FBDs were included in the U-FBDs group, while those without FBDs or other diseases were considered the control group. The psychological and sleep conditions of military personnel with U-FBDs were assessed using the SCL-90 scale and the Pittsburgh Sleep Quality Index scale, respectively. Health education and treatment were provided to individuals diagnosed with U-FBDs, and the improvements were evaluated after three months.

Results

Among 923 qualified questionnaires, 243 subjects was included in U-FBDs group and 240 in the control group. Smoking, alcohol consumption, and multiple seafaring missions were identified as risk factors for U-FBDs in military personnel on ocean-going missions. The U-FBDs group had significantly worse sleep quality, sleep efficiency, daytime dysfunction score, and total PSQI score compared to the control group (P < 0.05). Additionally, 10 factor scores of SCL-90 and the total score in the U-FBDs group were significantly higher than those in the control group (P < 0.01). Patients with U-FBDs also reported the highest rate of somatic symptoms (P < 0.01).

Conclusion

The onset of U-FBDs among military personnel on long-haul maritime may be closely related to mental, psychological, and sleep factors. Health education and treatment may help improve the symptoms of U-FBDs.

Efficacy of washed microbiota transplantation for therapeutic targets of refractory functional constipation and the influencing factors: a single-center, retrospective, 24-week follow-up study

BACKGROUND

The efficacy of washed microbiota transplantation (WMT) in terms of refractory functional constipation (FC)-related therapeutic targets and influencing factors have not been elucidated. This study aimed to assess the efficacy and influencing factors of WMT in treating refractory FC-related therapeutic targets.

METHODS

The clinical data of patients diagnosed with refractory FC and received with WMT were retrospectively collected. The therapeutic targets included straining, hard stools, incomplete evacuation, a sense of anorectal obstruction, manual maneuvers, and decreased stool frequency. Each target was recorded as 1 (yes) or 0 (no). All patients were followed up for approximately 24 weeks from the end of the first course of WMT. The primary outcomes were the improvement rates for the individual therapeutic targets and the overall response in respect of the therapeutic targets decreased by 2 at weeks 4, 8, and 24. The secondary outcomes were the clinical remission rate (i.e., the proportion of patients with an average of 3 or more spontaneous complete bowel movements per week), clinical improvement rate (i.e., the proportion of patients with an average increase of 1 or more SCBMs/week or patients with remission), stool frequency, Wexner constipation score, Bristol Stool Form Scale (BSFS) score, and adverse events. The factors influencing the efficacy were also analyzed.

RESULTS

Overall, 63 patients with 112 WMT courses were enrolled. The improvement rates at weeks 8 and 24 were 45.6% and 35.0%, 42.9% and 38.6%, 45.0% and 35.7%, 55.6% and 44.4%, and 60.9% and 50.0%, respectively, for straining, hard stools, incomplete evacuation, a sense of anorectal obstruction, and decreased stool frequency. The overall response rates were 49.2%, 50.8%, and 42.9%, respectively, at weeks 4, 8, and 24. The rates of clinical remission and clinical improvement were 54.0% and 68.3%, respectively, at weeks 4. The stool frequency, BSFS score, and Wexner constipation score tended to improve post-WMT. Only 22 mild adverse events were observed during the 112 WMT courses and the follow-up. The number of WMT courses was identified to be the independent factor influencing the efficacy.

CONCLUSIONS

WMT is efficacious in improving refractory FC-related therapeutic targets. The effectiveness of WMT in the management of FC is enhanced with the administration of multiple courses.

Brain-bacteria-gut axis and oxidative stress mediated by intestinal mucosal microbiota might be an important mechanism for constipation in mice

Intestinal microbiota disorder was associated with constipation. This study investigated the microbiota-gut-brain axis and oxidative stress mediated by intestinal mucosal microbiota in mice with spleen deficiency constipation. The Kunming mice were randomly divided into the control (MC) group and the constipation (MM) group. The spleen deficiency constipation model was established by gavage with Folium sennae decoction and controlled diet and water intake. The body weight, spleen and thymus index, 5-Hydroxytryptamine (5-HT) and Superoxide Dismutase (SOD) content were significantly lower in the MM group than the MC group, the content of vasoactive intestinal peptide (VIP) and malondialdehyde (MDA) content were significantly higher than the MC group. The Alpha diversity of intestinal mucosal bacteria was not changed but beta diversity was changed in mice with spleen deficiency constipation. Compared to the MC group, the relative abundance of Proteobacteria was an upward trend and the Firmicutes/Bacteroidota (F/B) value was a downward trend in the MM group. There was a significant difference in the characteristic microbiota between the two groups. In the MM group, Brevinema, Akkermansia, Parasutterella, Faecalibaculum, Aeromonas, Sphingobium, Actinobacillus, and other pathogenic bacteria were enriched. Meanwhile, there was a certain relationship between the microbiota and gastrointestinal neuropeptide and oxidative stress indicators. The community structure of intestinal mucosal bacteria in mice with spleen deficiency constipation was changed, which was characterized by the reduction of F/B value and enrichment of Proteobacteria. Microbiota-gut-brain axis may be important for spleen deficiency constipation.

Exploring Pharmacological Treatments for Chronic Idiopathic Constipation in Adults: A Look Back to the Future

Despite great progress in pharmaceutical research, the medical treatment of chronic idiopathic constipation is far from ideal. The aim of the present article was to review literature data, focusing on poorly studied or commercially unavailable/unapproved drugs potentially useful for the treatment of chronic idiopathic constipation in adults. An extensive online literature search was conducted using the keywords "chronic constipation", "colon", "constipation", "drugs", "laxatives", and "treatment", in various combinations between January 1960 and December 2022. The literature search showed the presence of some drugs whose efficacy has only recently been demonstrated by modern investigations, and which are likely to be incorporated into future guidelines, of others that are proven effective and potentially effective on constipated patients but limited by small or relatively old studies, or by side effects which could be used in experienced hands, and of others that might be useful but lack a solid scientific background. Looking into the future for patients with chronic constipation might add some more tools to the therapeutic portfolio, especially for certain subgroups of these patients.

Electroacupuncture Improves Intestinal Motility through Exosomal miR-34c-5p Targeting SCF/c-Kit Signaling Pathway in Slow Transit Constipation Model Rats

Background. The pathogenesis of slow transit constipation (STC) is associated with exosomal miR-34c-5p. Electroacupuncture (EA) improves gastrointestinal motility in gastrointestinal disorders, especially STC. Our study aimed to explore the mechanism by which EA improves intestinal motility by modulating the release of exosomes and the transmission of exosomal miR-34c-5p. Methods. Fifty rats were randomly divided into five groups. STC model rats were induced, and GW4869, the exosome release inhibitor, was used to inhibit the release of exosome. The serum exosomes were authenticated under a transmission electron microscope and nanoparticle tracking analysis. RT-qPCR detected the expression of miR-34c-5p in serum exosomes and colonic tissues. The fecal number in 24 hours, Bristol scores, and intestinal transit rates were used to assess intestinal motility. Subsequently, hematoxylin and eosin (H&E) staining was used to examine the colonic mucosal histology. Finally, the expression of stem cell factor (SCF) and receptor tyrosine kinase (c-Kit) protein was measured using immunohistochemistry staining. Results. We found that EA upregulated exosomal miR-34c-5p in serum and downregulated miR-34c-5p in colonic tissues ( $P<0.01$ ). EA improved fecal numbers in 24 hours, Bristol scores, and intestinal transit rates in STC rats ( $P<0.01$ ). EA recovered the colonic histological structure and enhanced the expression of SCF and c-Kit protein ( $P<0.01$ ). The therapeutic effect of EA was attenuated after inhibiting the release of the exosome. Conclusion. Our results indicated that EA improves intestinal motility in STC rats by transporting of exosomal miR-34c-5p targeting the SCF/c-Kit signaling pathway.

Intestinal mucosal barrier in functional constipation: Dose it change?

BACKGROUND

The intestinal mucosal barrier is the first line of defense against numerous harmful substances, and it contributes to the maintenance of intestinal homeostasis. Recent studies reported that structural and functional changes in the intestinal mucosal barrier were involved in the pathogenesis of several intestinal diseases. However, no study thoroughly evaluated this barrier in patients with functional constipation (FC).

AIM

To investigate the intestinal mucosal barrier in FC, including the mucus barrier, intercellular junctions, mucosal immunity and gut permeability.

METHODS

Forty FC patients who fulfilled the Rome IV criteria and 24 healthy controls were recruited in the Department of Gastroenterology of China-Japan Friendship Hospital. The colonic mucus barrier, intercellular junctions in the colonic epithelium, mucosal immune state and gut permeability in FC patients were comprehensively examined. Goblet cells were stained with Alcian Blue/Periodic acid Schiff (AB/PAS) and counted. The ultrastructure of intercellular junctional complexes was observed under an electron microscope. Occludin and zonula occludens-1 (ZO-1) in the colonic mucosa were located and quantified using immunohistochemistry and quantitative real-time polymerase chain reaction. Colonic CD3+ intraepithelial lymphocytes (IELs) and CD3+ lymphocytes in the lamina propria were identified and counted using immunofluorescence. The serum levels of D-lactic acid and zonulin were detected using enzyme-linked immunosorbent assay.

RESULTS

Compared to healthy controls, the staining of mucus secreted by goblet cells was darker in FC patients, and the number of goblet cells per upper crypt in the colonic mucosa was significantly increased in FC patients (control, 18.67 ± 2.99; FC, 22.42 ± 4.09; P = 0.001). The intercellular junctional complexes in the colonic epithelium were integral in FC patients. The distribution of mucosal occludin and ZO-1 was not altered in FC patients. No significant differences were found in occludin (control, 5.76E-2 ± 1.62E-2; FC, 5.17E-2 ± 1.80E-2; P = 0.240) and ZO-1 (control, 2.29E-2 ± 0.93E-2; FC, 2.68E-2 ± 1.60E-2; P = 0.333) protein expression between the two groups. The mRNA levels in occludin and ZO-1 were not modified in FC patients compared to healthy controls (P = 0.145, P = 0.451, respectively). No significant differences were observed in the number of CD3+ IELs per 100 epithelial cells (control, 5.62 ± 2.06; FC, 4.50 ± 2.16; P = 0.070) and CD3+ lamina propria lymphocytes (control, 19.69 ± 6.04/mm²; FC, 22.70 ± 11.38/mm²; P = 0.273). There were no significant differences in serum D-lactic acid [control, 5.21 (4.46, 5.49) mmol/L; FC, 4.63 (4.31, 5.42) mmol/L; P = 0.112] or zonulin [control, 1.36 (0.53, 2.15) ng/mL; FC, 0.94 (0.47, 1.56) ng/mL; P = 0.185] levels between FC patients and healthy controls.

CONCLUSION

The intestinal mucosal barrier in FC patients exhibits a compensatory increase in goblet cells and integral intercellular junctions without activation of mucosal immunity or increased gut permeability.

DIAGNOSIS AND MANAGEMENT OF CHRONIC IDIOPATHIC CONSTIPATION: A NARRATIVE REVIEW FROM A BRAZILIAN EXPERT TASK FORCE

ABSTRACT Background Chronic idiopathic constipation (CIC) is a condition that widely affects the global population, represents relevant healthcare resource utilization and costs, and impacts the individual’s well-being. Objective To review the consensus of expert societies and published guidelines on the diagnosis and treatment of CIC in adults, seeking to assist reasoning and decision-making for medical management of patients with CIC and provide a practical reference material. Methods A Brazilian medical task force searched the scientific literature in the following electronic databases: MEDLINE/PubMed, SciELO, EMBASE and Cochrane, using the following descriptors: chronic constipation, diagnosis, management of chronic constipation. In addition, a review of articles on the mechanism of action, safety, and efficacy of therapeutic options available in Brazil was carried out. Results The diagnostic approach and the understanding of the pathophysiology present in CIC are essential items to indicate the appropriate therapy and to understand the ecosystem of the patient’s needs. Conclusion CIC is a common condition in adults, occurring more frequently in the elderly and in women. Proper management is defined by detailed medical history and physical examination, together with appropriate therapeutics, regardless pharmacological or not, and depending on the best moment of indication. This way, the impact on quality of life is also optimized.

Current Overview on Clinical Management of Chronic Constipation

Constipation is one of the major gastrointestinal disorders diagnosed in clinical practice in Western countries. Almost 20% of population suffer from this disorder, which means constipation is a substantial utilization of healthcare. Pathophysiology of constipation is complex and multifactorial, where aspects like disturbance in colonic transit, genetic predisposition, lifestyle habits, psychological distress, and many others need to be taken into consideration. Diagnosis of constipation is troublesome and requires thorough accurate examination. A nonpharmacological approach, education of the patient about the importance of lifestyle changes like diet and sport activity state, are the first line of therapy. In case of ineffective treatment, pharmacological treatments such as laxatives, secretagogues, serotonergic agonists, and many other medications should be induced. If pharmacologic treatment fails, the definitive solution for constipation might be surgical approach. Commonness of this disorder, costs of medical care and decrease in quality life cause constipation is a serious issue for many specialists. The aim of this review is to present current knowledge of chronic constipation and management of this disorder.