Current Pharmaceutical Design - Volume 24, Issue 18, 2018

Background: Physical activity can be involved in the prevention of gastrointestinal (GI)-tract diseases, however, the results regarding the volume and the intensity of exercise considered as beneficial for protection of gastrointestinal organs are conflicting. Aims and Methods: The main objective of this review is to provide a comprehensive and updated overview on the beneficial and harmful effects of physical activity on the gastrointestinal tract. We attempted to discuss recent evidence regarding the association between different modes and intensity levels of exercise and physiological functions of the gut and gut pathology. Results: The regular, moderate exercise can exert a beneficial effect on GI-tract disorders such as reflux esophagitis, peptic ulcers, cholelithiasis, constipation and Inflammatory Bowel Disease (IBD) leading to the attenuation of the symptoms. This voluntary exercise has been shown to reduce the risk of colorectal cancer. On the other hand, there is considerable evidence that the high-intensity training or prolonged endurance training can exert a negative influence on GI-tract resulting in the exacerbation of symptoms. Conclusion: Physical activity can exhibit a beneficial effect on a variety of gastrointestinal diseases, however, this effect depends upon the exercise mode, duration and intensity. The accumulated evidence indicate that management of gastrointestinal problems and their relief by the exercise seems to be complicated and require adjustments of physical activity training, dietary measures and medical monitoring of symptoms. More experimental and clinical studies on the effects of physical activity on GI-tract disorders are warranted. Especially, the association between the exercise intensity and data addressing the underlying mechanism(s) of the exercise as the complementary therapy in the treatment of gastrointestinal disorders, require further determination in animal models and humans.

The number of people who are overweight and obese are continuously increasing both in the adult and adolescent populations. Coinciding with this is the increased prevalence of health problems such as type 2 diabetes (T2D). Bariatric surgery is the only proven long-term treatment of obesity and may induce remission of T2D, although the underlying mechanisms are unknown. The translational studies presented here might provide insight on the mechanism of steady-state energy balance of the obese phenotype using a special time-restricted feeding regimen for weight loss during the steady-state energy balance; mechanism by vagal blocking therapy (vBLoc® therapy) as a new treatment for obesity; and possible mechanism behind the remission of T2D following gastric bypass surgery.

Gastrointestinal (GI) mucosal integrity is based on the balance of aggressive and protective mechanisms. Mucosal damage may occur when the injurious factors become dominant or the mucosal defensive processes are impaired. The main target of the therapy against GI mucosal injury is the reduction of aggressive factors, however, the therapeutic possibilities for stimulation of mucosal defensive processes are rather limited. This overview focuses on the gastric and intestinal mucosal protective mechanisms and discusses the main targets that increase protective processes and increase the mucosal resistance to injurious stimuli at pre-epithelial, epithelial and sub-epithelial levels.

Cancer cachexia, one of the metabolic syndromes caused by cancer, is a devastating and miserable condition encountered in more than 50% of terminal cancer patients presenting with significant weight loss associated with skeletal muscle atrophy and fat loss. Though cachexia may account for up to 20% of cancer deaths, no significant treatment is still lacking and is of urgent unmet medical need in cancer treatment. Therefore, understanding the underlying molecular mechanisms is essential for anticipating therapeutic approaches. Since the primary events driving cachexia are mediated via either the central nervous system relatedor inflammation related-anorexia, hypoanabolism, and hypercatabolism, therapy usually targets nutritional support to compensate reduced food intake along with some anti-inflammatory agents to cover specific inflammation-related metabolic derangement, and encourages exercise to supplement reduced physical activity, but all proven to be not so effective so far. Therefore, combination therapies such as a standard multi-modal package including an anorexic agent, megestrol acetate, and anti-inflammatory agent coupled with the development of potential novel therapeutics promise a new era in rescuing patients from cancer cachexia. In this review, we propose the potential application of BPC157, one of the active cytoprotective agents isolated from gastric juices for cancer cachexia. Before clinical trial, we introduced the evidence showing BPC157 rescued from cancer cachexia supported with explored mode of actions.

4-MP is a potent competitive inhibitor of ADH activity with an affinity about a 1000 times more than toxic alcohols. 4-MP was shown to reduce the formation of toxic metabolites in lethal methanol and ethylene glycol poisoning in animal models and in methanol poisoning in humans. 4-MP has long-lasting gastroprotective effect against ethanol and other chemically induced acute gastric mucosa lesions in rats. We showed, for the first time, that 4-MP also provides significant protection of the human stomach against alcohol induced acute mucosal injury.

Background: Vagal nerve plays an important role in the stomach function. The cholinergic nerves are the most abundantly distributed nerves in the gastric tissue. It has recently been reported that the vagal nerve is significantly related to both gastric cancer development and progression. However, its relation to the mesenchymal tumor, including MALT lymphoma, is not known. In this study, we investigated the effect of unilateral truncal vagotomy on gastric MALT lymphoma development by using Helicobacter heilmannii-infected mouse model as well as that of bilateral truncal vagotomy on stress-induced ulcer formation. Methods: In the first part of this study, the distribution of the cholinergic nerves in the rat gastric mucosa and the effect of bilateral truncal vagotomy, as well as various kinds of agents acting on autonomic nerves in rats, were investigated by the histochemical and macroscopic method. In the second part, we employed MALT lymphoma formation in C57BL/6NCrl mice that were infected with Helicobacter heilmannii. A total of 38 infected mice underwent unilateral vagotomy under microscopy. The mice were randomized into 4 groups from which samples were collected; 2, 3, 4 and 6 months after infection. Both the anterior and posterior sides of the stomachs were sampled from each mouse for pathological and immunohistochemical analyses. Results: The bilateral truncal vagotomy significantly suppressed the restraint-induced gastric ulcer formation in rats, while bethanechol, and 6-hydroxydopamine led to an increase of the gastric ulcer formation. In the unilateral truncal vagotomy study using MALT lymphoma, the thickness of the gastric mucosa was reduced in the vagotomized side compared to the non-vagotomized side. Furthermore, the gastric MALT lymphoma was more prominently found in the vagotomized anterior side of stomach compared with that in the non-vagotomized posterior side of stomach. Substance P-immunoreactive nerves markedly increased surrounding the MALT lymphoma and the neurokinin-1 receptor immunoreactive lymphocytes increased within the MALT lymphoma in the vagotomized side. In conclusion, vagotomy enhanced gastric MALT lymphoma development possibly through the substance P-neurokinin-1 receptor pathway.

The wound healing and the barrier restoration of the gastrointestinal (GI) mucosa must be continuously ensured to allow homeostasis of the gastrointestinal tract and of all the surrounding tissues. Several lines of the evidence report a key role of innate immunity, and in particular of Pattern Recognition Receptors (PRRs), in controlling the homeostasis of GI tract by sensing commensal and pathogen bacteria, activating the immune response and regulating epithelial repair, thus guaranteeing the morphological and functional recovery of the injured tissue. We will discuss the role of a particular class of PRRs - the Formyl Peptide Receptors - in the homeostasis of GI mucosa. We here report the results of studies that strongly suggest the possibility that the activation of FPRs is crucial in the maintenance of homeostasis of the GI tract and provide indications of the potential clinical relevance of new treatment regimens involving FPR modulation for several GI disorders.

Commonly, the angiogenic growth factors signify healing. However, gastrointestinal ulceration is still poorly understood particularly with respect to a general pharmacological/pathophysiological role of various angiogenic growth factors implemented in growth factors wound healing concept. Thereby, we focused on the stable gastric pentadecapeptide BPC 157, a peptide given always alone vs. standard peptidergic angiogenic growth factors (EGF, FGF, VEGF), and numerous carriers. Further, we reviewed how the gastrointestinal tract healing could be generally perceived (i) in terms of angiogenic growth factors, and/or (ii) through the healing of extragastrointestinal tissues healing, such as tendon, ligament, muscle and bone, and vice versa. Respected were the beneficial effects obtained with free peptides or peptides with different carriers; EGF, FGF, VEGF, and BPC 157, their presentation along with injuries, and a healing commonality, providing their implementation in both gastrointestinal ulcer healing and tendon, ligament, muscle and bone healing. Only BPC 157 was consistently effective in all of the models of acute/chronic injury of esophagus, stomach, duodenum and lower gastrointestinal tract, intraperitoneally, per-orally or locally. Unlike bFGF-, EGF-, VEGF-gastrointestinal tract studies demonstrating improved healing, most of the studies on tendon, muscle and bone injuries provide evidence of their (increased) presentation along with the various procedures used to produce beneficial effects, compared to fewer studies in vitro, while in vivo healing has a limited number of studies, commonly limited to local application, diverse healing evidence with diverse carriers and delivery systems. Contrary to this, BPC 157 - using same regimens like in gastrointestinal healing studies - improves tendon, ligament and bone healing, accurately implementing its own angiogenic effect in the healing. Thus, we claim that just BPC 157 represents in practice a pharmacological and pathophysiological role of various peptidergic growth factors.

Years ago, we revealed a novel cytoprotective mediator, stable gastric pentadecapeptide BPC 157, particular anti-ulcer peptide that heals different organs lesions when given as a therapy, native in human gastric juice while maintaining GI-tract mucosal integrity, already tested in trials (ulcerative colitis and now multiple sclerosis). The stomach cytoprotection is the most fundamental concept, stomach cell protection and endothelium protection are largely elaborated, but so far cell, protection and endothelium protection outside of the stomach were not implemented in the therapy. However, having managed these two points, stomach cell protection and endothelium protection, either one or together, even much more than standard cytoprotective agents do, BPC 157 employed large scale of its beneficial effects seen in various organs. Providing endothelium protection, BPC 157 was shown to prevent formation and reverse established thrombosis in anastomosed abdominal aorta as well as venous thrombosis after inferior caval vein occlusion, and attenuate bleeding prolongation and thrombocytopenia after amputation, without or with anticoagulants, or venous occlusion, and finally counteract effect of L-NAME and/or L- arginine. Now, with BPC 157 application, we reveal the third most important part of the cytoprotection concept: with the stomach cell and endothelium protection to recover mucosal integrity, BPC 157 as prototype cytoprotective agent should also control blood vessel function, depending upon injury, perforated defect or vessel obstruction. After a perforated injury (i.e., stomach), BPC 157 therapy activates blood vessels “running” towards defect. After obstruction (i.e., inferior caval vein), BPC 157 activates vessels “running” towards bypassing defect, collaterals functioning. Reestablished blood flow, and largely reversed injurious course may practically implement the cytoprotection concept.

Endogenous prostaglandins (PGs), produced from arachidonic acid by the two isoforms of cyclooxygenase (COX), play a pivotal role in maintaining mucosal integrity by modulating various functions of the gastrointestinal (GI) tract, and PGE2 is most effective in these actions. The PGE2 receptor is classified into 4 specific G-protein coupled subtypes, EP1-EP4, and their distribution accounts for the multiple effects of this prostanoid. PGE2 prevents acid-reflux esophagitis and indomethacin-induced gastric lesions through EP1 receptors, while endogenous PGs protect the stomach against cold restraint stress mediated by mainly PGI2/IP receptors and partly EP4 receptors. PGE2 also exhibits a protective effect against acid-induced duodenal damage and indomethacin-induced small intestinal lesions mediated by EP3/EP4 receptors; these effects in the stomach, duodenum, or small intestine are associated functionally with inhibition of gastric contraction (EP1), stimulation of duodenal HCO3 - secretion (EP3/EP4), or suppression of bacterial invasion due to the inhibition of intestinal motility (EP4) as well as stimulation of mucus secretion (EP3/EP4), respectively. PGE2 also prevents ischemiainduced enteritis and dextran sulfate sodium-induced colitis mediated by EP4 receptors, and the protective mechanisms may be related to the stimulation of mucus secretion and the down-regulation of immune response, respectively. Furthermore, PGE2 shows a healing-promoting effect on gastric ulcers and small intestinal lesions through the up-regulated expression of vascular endothelial growth factor (VEGF) and stimulation of angiogenesis via the activation of EP4 receptors. Finally, COX-1 is mainly responsible for the production of endogenous PGs involved in mucosal protection, while COX-2 is mainly responsible for those involved in the healing of gastric ulcers or small intestinal lesions. These findings contribute to future development of new strategies for the treatment of GI diseases.

The pancreas, the salivary glands and the dental enamel producing ameloblasts have marked developmental, structural and functional similarities. One of the most striking similarities is their bicarbonate-rich secretory product, serving acid neutralization. An important difference between them is that while pancreatic juice and saliva are delivered into a lumen where they can be collected and analyzed, ameloblasts produce locally precipitating hydroxyapatite which cannot be easily studied. Interestingly, the ion and protein secretion by the pancreas, the salivary glands, and maturation ameloblasts are all two-step processes, of course with significant differences too. As they all have to defend against acid exposure by producing extremely large quantities of bicarbonate, the failure of this function leads to deteriorating consequences. The aim of the present review is to describe and characterize the defense mechanisms of the pancreas, the salivary glands and enamel-producing ameloblasts against acid exposure and to compare their functional capabilities to do this by producing bicarbonate.

The human gastrointestinal tract is exposed to a variety of toxic agents, such as Helicobacter pylori (H.pylori), Nonsteroidal Anti-inflammatory Drugs (NSAIDs), gastric acid, enteric pathogenic bacteria, excessive auto immune reactions, and chronic mental stresses. These stressors generate free radicals within the gastrointestinal tissues, causing chronic inflammatory diseases, ulcers, cancers, and functional disturbances. Recent studies have demonstrated that some natural food compounds upregulate the nuclear factor erythroid 2-related factor 2- mediated antioxidant system, ameliorating or preventing these disorders. We have previously shown that dietary intake of sulforaphane-rich broccoli sprouts, ameliorates gastric inflammation induced by H. pylori, prevents NSAIDs-induced small intestinal injury, and improve functional constipation. There have been many other compounds, which enhance the nuclear factor erythroid 2-related factor 2-mediated antioxidant system, sufficient evidence for their clinical efficacy has not yet been provided. In addition, we have to pay attention to some reports, which have shown that excessive stimulation of nuclear factor erythroid 2-related factor 2 enhance chemoresistance and facilitates growth of cancer cells.

The risk of developing Peptic Ulcer Disease (PUD) was shown to be associated with genetic inheritance, lifestyle and social status of the patients. Unhealthy lifestyle habits and failure in coping with stress have been closely associated with the occurrence of PUD. In contrary, limiting the use of analgesic drugs and glucocorticoids, controlling environmental and socioeconomic factors that predispose to H. Pylori infection, having a balanced diet, exercising regularly, coping successfully with stress, avoiding smoking, limiting alcohol intake and getting sufficient night sleep are essential in prevention and healing of PUD.