Protective action of diosmectite treatment on digestive disturbances induced by intestinal anaphylaxis in the guinea-pig

Present and Future Therapeutic Approaches to Barrier Dysfunction

There is converging and increasing evidence, but also uncertainty, for the role of abnormal intestinal epithelial barrier function in the origin and development of a growing number of human gastrointestinal and extraintestinal inflammatory disorders, and their related complaints. Despite a vast literature addressing factors and mechanisms underlying changes in intestinal permeability in humans, and its connection to the appearance and severity of clinical symptoms, the ultimate link remains to be established in many cases. Accordingly, there are no directives or clinical guidelines related to the therapeutic management of intestinal permeability disorders that allow health professionals involved in the management of these patients to carry out a consensus treatment based on clinical evidence. Instead, there are multiple pseudoscientific approaches and commercial propaganda scattered on the internet that confuse those affected and health professionals and that often lack scientific rigor. Therefore, in this review we aim to shed light on the different therapeutic options, which include, among others, dietary management, nutraceuticals and medical devices, microbiota and drugs, and epigenetic and exosomes-manipulation, through an objective evaluation of the scientific publications in this field. Advances in the knowledge and management of intestinal permeability will sure enable better options of dealing with this group of common disorders to enhance quality of life of those affected.

The Role of Purported Mucoprotectants in Dealing with Irritable Bowel Syndrome, Functional Diarrhea, and Other Chronic Diarrheal Disorders in Adults

Chronic diarrhea is a frequent presenting symptom, both in primary care medicine and in specialized gastroenterology units. It is estimated that more than 5% of the global population suffers from chronic diarrhea. and that about 40% of these subjects are older than 60 years. The clinician is frequently faced with the need to decide which is the best therapeutic approach for these patients. While the origin of chronic diarrhea is diverse, impairment of intestinal barrier function, dysbiosis. and mucosal micro-inflammation are being increasingly recognized as underlying phenomena characterizing a variety of chronic diarrheal diseases. In addition to current pharmacological therapies, there is growing interest in alternative products such as mucoprotectants, which form a mucoadhesive film over the epithelium to reduce and protect against the development of altered intestinal permeability, dysbiosis, and mucosal micro-inflammation. This manuscript focuses on chronic diarrhea in adults, and we will review recent evidence on the ability of these natural compounds to improve symptoms associated with chronic diarrhea and to exert protective effects for the intestinal barrier.

Chemotherapy-induced diarrhoea in dogs and its management with smectite: Results of a monocentric open-label randomized clinical trial

Chemotherapy-induced diarrhoea (CID) is a frequent chemotherapy adverse event in dogs. Yet, there is currently no consensus regarding its management. Smectite is a natural medical clay, widely used in the treatment of acute diarrhoea in humans. The objectives of this study were to assess the efficacy of smectite in the management of CID in dogs, and to collect epidemiological data on CID. For each episode of diarrhoea, dogs were randomized into two management groups: Smectite group, receiving smectite at 0.5 g/kg PO per day divided in two to three doses initiated at the start of CID; control group, without initial medication. In both groups, rescue metronidazole was prescribed if CID progressed or was not improved within 48 hours. Sixty dogs were recruited and received 426 chemotherapy administrations between June 2017 and March 2019. The incidence rate of CID was 110/426 (25.8%, 95% CI: 21.7%-30.2%), and significantly differed between the chemotherapeutic drugs administered (P < .001). Metronidazole was administered in 5/54 events (9.3%, 95% CI: 3.1%-20.3%) in the smectite group and in 40/56 events (71.4%, 95% CI: 57.5%-82.3%) in the control group (P < .001). The time to resolution of diarrhoea was shorter (P < .001) in the smectite group (median: 19.5 hours, interquartile range [IQR]: 13.5-32 hours) compared with the control group (median: 53 hours, IQR: 31.5-113.5 hours). The results of this study support the administration of smectite in the first-line management of CID in dogs.

Mitigation of colitis with NovaSil clay therapy

BACKGROUND/AIMS

Five million people currently live with Crohn's disease (CD) or ulcerative colitis, the two major forms of inflammatory bowel disease. Available treatments frequently result in side effects that compromise the immune health of the patient. Consequently, alternative therapies that cause fewer systemic effects are needed. Dioctahedral smectite clays have been utilized to treat medical conditions, including diarrheal and enteric disease. Herein, we report the ability of a refined dioctahedral smectite (NovaSil, NS) to sorb inflammatory proteins and reduce inflammation in a TNBS (2,4,6-trinitrobenzenesulfonic acid) mouse model of CD. We also investigated whether NS could rescue gut microbial diversity in TNBS-induced mice.

METHODS

ELISA, X-ray diffraction, and transmission electron microscopy were employed to characterize the NS-cytokine interaction in vitro. A TNBS mouse colitis model was utilized to study the efficacy of NS supplementation for 4 weeks. The three treatment groups included control, TNBS, and TNBS + NS. DNA was extracted from feces and sorted for bacterial phylogenetic analysis.

RESULTS

Results suggest that NS binds TNFα in vitro. In TNBS-treated mice, supplementation with NS significantly reduced weight loss, and serum proinflammatory cytokine levels (IL-2, IL-6, and IL-12, TNFα, IFNγ) compared with the TNBS group. TNBS-treated mice demonstrated a significant reduction in gut microbiota species richness when compared with the TNBS + NS group and control group.

CONCLUSIONS

NovaSil mitigated the effects of TNBS-induced colitis based on reduction in systemic markers of inflammation, significant improvement in weight gain, and intestinal microbial profile.

Differences and commonalities in physical, chemical and mineralogical properties of Zanzibari geophagic soils

The function of human geophagy has long been questioned. We sought to test hypotheses concerning its potential physiological effects through analysis of soils and patterns in geophagy behavior. Eleven samples of geophagic soils consumed by pregnant women on Pemba Island, Zanzibar, Tanzania, were characterized according to their color, texture, major element chemistry, trace element chemistry, bulk mineralogy, and clay mineralogy. An epidemiological study (N = 2367) and ethnographic interviews (N = 57) on Pemba yielded information about geophagic behaviors and socio-demographic and biological characteristics of those who consumed earth. The soils varied widely in color, ranging from light red to white through various shades of brown and yellow, and texture ranged from clay to sand. Major element chemistry of the soils also varied greatly; most were low in Fe and Ca. Trace elements, whether of biological or non-biological significance, were uniformly low when compared with normal ranges of mineral soils. The sole commonality among the samples is that all clay fractions were dominated by a kaolin mineral: kaolinite, halloysite, or a mixture of both. Geophagy behavior also varied greatly, with one major exception: a greater proportion of pregnant women (7.1%) and young children (4.5%) consumed earth than non-pregnant women (0.2%) or men (0%). The presence of kaolin mineral in all samples, its palliative and detoxifying properties, and the highest prevalence of geophagy among those most biologically vulnerable suggest that geophagy may be a protective behavior.

Clinical role of diosmectite in the management of diarrhea

BACKGROUND

Diosmectite (DS), an antidiarrheal absorbent natural clay, was proposed for treatment of acute gastroenteritis and more recently considered for diarrhea within the functional bowel disorder syndrome.

OBJECTIVE

To review pharmacology efficacy, mechanisms of action and safety of DS.

METHODS

We consulted PubMed/Medline using the keywords of smectite and diarrhea or gastroenteritis, and reviewed most recent recommendations by scientific societies.

CONCLUSIONS

Solid data show that DS is effective in infectious diarrhea, mainly as an ion antisecretory agent and in preventing intestinal damage. Despite clinical data being consistent and convincing, DS is not considered as first-line treatment because of the presence of alternative therapeutic options. However, it definitely may play a role in infectious colitis, where treatment options are less convincing. Some available evidences demonstrate a role of DS in functional diarrhea.

Chapter 11.6 Clays and Clay Minerals as Drugs

This chapter discusses the applications of clays and clay materials as drugs. Clay minerals are efficient against several aggressors that cause major disorders of the gut. These beneficial effects of clay minerals (on the gastrointestinal mucosa) are associated with two mechanisms of action: (1) adsorption of the aggressors or their toxic secretions and (2) modification of the thickness and rheological properties of the adherent mucus, reinforcing the natural defenses of the gastrointestinal mucosa. At the surface of the gut, a mucus gel adheres to the epithelial cells of the mucosa. This adherent mucus is dynamic, being continuously secreted by the calceiform cells and regularly eroded by environmental aggressors present in the gut lumen. The mucus gel is largely composed of glycoprotein polymers, lipids, and proteins linked together by covalent bonds. It acts as a physical barrier protecting the mucosa against penetration by extraneous molecules and mechanical injury. By maintaining a pH gradient and competing with the epithelial surface for microorganisms, the mucus gel also acts as a chemical barrier.

Anti-inflammatory effect of diosmectite in hapten-induced colitis in the rat

1. Diosmectite is a natural silicate effectively used in the treatment of infectious diarrhoea. Its antidiarrhoeal properties involve adsorption of toxins and bacteria and modifications of the rheological characteristics of gastrointestinal mucus. Hence, the aim of this study was to test the intestinal anti-inflammatory activity of diosmectite. 2. Diosmectite (500 mg x kg(-1) day(-1), p.o.) was administered as a post-treatment to rats with chronic trinitrobenzene sulphonic acid colitis. Colonic status was checked 1 and 2 weeks after colitis induction by macroscopic, histological and biochemical examination. 3. Diosmectite post-treatment resulted in amelioration of the morphological signs (intestinal weight, macroscopic damage, necrosed area, histology) and biochemical markers (myeloperoxidase activity, glutathione levels, MUC2 expression, inducible nitric oxide synthase and interleukin-1beta (IL-1beta) and leukotriene B(4) synthesis), as well as in the reduction of the severity of diarrhoea. The effect of the clay was comparable to that of sulphasalazine (50 mg x kg(-1) day(-1)). 4. 5. Diosmectite exhibited a dose-dependent capacity to adsorb proteins in vitro as well as a dose-dependent inhibitory effect on the basolateral secretion of IL-8 by lipopolysaccharide (LPS)-stimulated HT29 cells. Diosmectite had a dose-dependent inhibitory effect on IL-1beta production by LPS-stimulated THP-1 cells. 6. The effect of diosmectite on MUC2 was post-transcriptional, since mRNA levels were unaffected. However, diosmectite is able to upregulate MUC2 mRNA levels in HT29-MTX cells. 7. Diosmectite has anti-inflammatory activity administered as a post-treatment. Possible mechanisms include adsorption of luminal antigens, increase of colonic mucin levels and possibly a direct modulatory action of cytokine production by mucosal cells.

Comparative effects of nonpeptide tachykinin receptor antagonists on experimental gut inflammation in rats and guinea-pigs

Previous studies have shown tachykinins implicated in gut inflammation. The aim of this work was to evaluate the effect of treatments with tachykinin NK1, NK2, and NK3 selective receptor antagonists on the development of gut inflammation induced by trinitrobenzenesulfonic acid (TNBS) in rats and guinea-pigs. On day 0, rats and guinea-pigs received an intraluminal instillation of TNBS/ethanol (40 mg/kg). Each group was daily treated with intraperitoneally injected NK1 (SR 140333; 0.3 mg/kg/day), NK2 (SR 48968; 5 mg/kg/day), or NK3 (SR 142801; 1, 5, or 10 mg/kg/day) receptor antagonists or their vehicle. On day 4, inflammatory levels were evaluated by measuring gut permeability, myeloperoxidase activity, macro- and microscopic damage scores. In TNBS treated rats, daily administration of SR 140333 (0.3 mg/kg/day) and SR 48968 (5 mg/kg/day) reduced colonic inflammation. In TNBS treated guinea-pigs, daily administration of SR 48968 (5 mg/kg/day) and SR 142801 (at 5 and 10 mg/kg/day) attenuated significantly ileal injury. These results suggest that non-peptide tachykinin receptor antagonists are potent anti-inflammatory agents on gut inflammation in rats and guinea-pigs. However, their activity depends upon the animal species and type of receptor considered.

Boosted systemic immune and local responsiveness after intestinal inflammation in orally sensitized guinea pigs

BACKGROUND & AIMS

Intestinal inflammation resulting in disruption of the mucosal barrier function has been proposed as a cause of increased incidence of allergic diseases. This study was designed to evaluate whether intestinal inflammation is able to change the immune responsiveness to sensitization and antigen challenge responses.

METHODS

Guinea pigs orally sensitized to cow's milk proteins were either treated or not treated with trinitrobenzenesulfonic acid (TNBS) to induce intestinal inflammation and compared with control animals (not sensitized). Systemic immune and local responsiveness to antigen challenge were assessed by measuring antibody serum titers, colonic fluid secretion, mucosal histamine level, and mucus depletion. Intestinal permeability was evaluated from 51Cr-ethylenediaminetetraacetic acid (EDTA) recovery and beta-lactoglobulin serum level.

RESULTS

Immunoglobulin E titers were higher in TNBS-treated animals than in non-TNBS-treated sensitized animals. Antigen challenge in TNBS-treated animals induced a fourfold increase of colonic secretion and greater histamine and mucus depletion than in non-TNBS-treated animals. Permeability to 51Cr-EDTA increased 5 days after TNBS treatment but was unchanged after antigen challenge. In contrast to controls, beta-lactoglobulin was not detected in the sera of challenged sensitized and TNBS-treated animals.

CONCLUSIONS

Intestinal inflammation increasing gut permeability enhances the sensitization process. Therefore, local anaphylactic reactions are exacerbated after antigen challenge.