Constipation Caused by Anti-calcitonin Gene-Related Peptide Migraine Therapeutics Explained by Antagonism of Calcitonin Gene-Related Peptide’s Motor-Stimulating and Prosecretory Function in the Intestine

The development of small-molecule calcitonin gene-related peptide (CGRP) receptor antagonists (gepants) and of monoclonal antibodies targeting the CGRP system has been a major advance in the management of migraine. In the randomized controlled trials before regulatory approval, the safety of these anti-CGRP migraine therapeutics was considered favorable and to stay within the expected profile. Post-approval real-world surveys reveal, however, constipation to be a major adverse event which may affect more than 50% of patients treated with erenumab (an antibody targeting the CGRP receptor), fremanezumab or galcanezumab (antibodies targeting CGRP). In this review article we address the question whether constipation caused by inhibition of CGRP signaling can be mechanistically deduced from the known pharmacological actions and pathophysiological implications of CGRP in the digestive tract. CGRP in the gut is expressed by two distinct neuronal populations: extrinsic primary afferent nerve fibers and distinct neurons of the intrinsic enteric nervous system. In particular, CGRP is a major messenger of enteric sensory neurons which in response to mucosal stimulation activate both ascending excitatory and descending inhibitory neuronal pathways that enable propulsive (peristaltic) motor activity to take place. In addition, CGRP is able to stimulate ion and water secretion into the intestinal lumen. The motor-stimulating and prosecretory actions of CGRP combine in accelerating intestinal transit, an activity profile that has been confirmed by the ability of CGRP to induce diarrhea in mice, dogs and humans. We therefore conclude that the constipation elicited by antibodies targeting CGRP or its receptor results from interference with the physiological function of CGRP in the small and large intestine in which it contributes to the maintenance of peristaltic motor activity, ion and water secretion and intestinal transit.

ANTIDIARRHEAL ACTIVITY TEST OF ETHANOLIC EXTRACT OF WHITE POMEGRANATE PEEL (PUNICA GRANATUM L.) IN MALE WHITE MICE (MUS MUSCULUS), SWISS WEBSTER LINE USING THE INTESTINAL TRANSIT METHOD

Objective: Diarrheal disease and its complications remain a major cause of morbidity and mortality in children, especially in developing countries. It is usually a symptom of an infection in the intestinal tract, which can be caused by a variety of bacterial, viral, parasitic or organisms. The purpose of this study was to determine the activity and dose of white pomegranate peel (Punica granatum L.) ethanol extract as an antidiarrheal in white male mice using the intestinal transit method. Methods: Mice were grouped into 5 groups: negative control (Na CMC 1 %), positive control (loperamide HCl 0.0104 mg/20 g mice BW), and pomegranate peel ethanol extract test group 1, 2, and 3 (dose of 16, 32, and 64 mg/20 g mice BW). The length of the intestine that the ink marker traversed from the pylorus to the end (which is black) was measured using a ruler. Results: Based on statistical analysis, there were significant differences between all groups (<0.05). The highest antidiarrheal activity was in the ethanolic extract of pomegranate peel at a dose of 64 mg/20 g mice BW with an inhibition percentage of 36.44% and higher than the positive control (29.81%). The inhibition percentage was also resulted by dose 1 and 2 (12.46% and 29.53%, respectively). Conclusion: From these results show a correlation that the higher the extract dose, the higher the antidiarrheal potential.

Effect of DA-9701 on the Gastrointestinal Motility in the Streptozotocin-Induced Diabetic Mice

Background: Compared to the general population, diabetic patients experience more frequent episodes of gastrointestinal (GI) motility dysfunction, owing to the disruption of functional innervations. DA-9701 is a new prokinetic agent formulated from the extracts of Pharbitidis semen and Corydalis tuber. Aim: To investigate the effect of DA-9701 on GI motility in an animal model of streptozotocin (STZ)-induced diabetes. Methods: Diabetes was induced in mice by intraperitoneal injection of STZ (40 mg/kg of body weight in 0.1 M citrate buffer) for 3 days. Diabetic mice were divided into four groups and administered DA-9701 in different doses (1, 3, and 10 mg/kg) or placebo for 2 weeks. Intestinal transit was assessed using charcoal meal movement. GI isometric contraction was measured by applying an isometric force transducer on a circular muscle strip of the antrum, ileum, and proximal colon of sacrificed mice. Gastric emptying rate was evaluated by measuring the dye percentage remaining in the stomach relative to the total dye amount recovered in a standardization group of mice. Results: Body weight and antral and small intestinal motility were less in diabetic mice than in control mice, and colonic motility was similar in both. DA-9701 showed a dose-dependent increase in the amplitude of spontaneous phasic contractions in the antrum, ileum, and colon in diabetic mice without influencing body weight or blood glucose levels. The degree of improvement was comparable between diabetic and control mice. Intestinal transit was significantly more delayed in diabetic mice than in controls (43 ± 7% vs. 67 ± 8%, p < 0.05); however, DA-9701 restored the delayed intestinal transit more effectively compared to placebo (75% vs. 50%). The gastric emptying rate was significantly more delayed in diabetic mice than in controls (43 ± 10% vs. 62 ± 12%, p < 0.05), and was improved by DA-9701 in a dose-dependent manner (50%, 55%, and 60% in mice treated with 1, 3, and 10 mg/kg of DA-9701, respectively, vs. 43% in placebo-treated and 60% in control mice). Conclusions: DA-9701 improved GI contractility without affecting blood sugar and body weight in diabetic mice. DA-9701 could improve the decreased GI motility and clinical symptoms in progressive diabetic patients.

P018 COLLABORATIVE APPROACH FOR SIMULTANEOUS REPAIR OF COMPLEX INCISIONAL HERNIA AND STOMA REVERSAL

Aim The simultaneous repair of incisional hernias (IH) and the reconstruction of the intestinal transit may pose a challenge for many surgeons. Collaboration between units specialized in abdominal wall and colorectal surgery can favor simultaneous treatment. We present our experience in the collaboration between specialized units for the simultaneous treatment of complex incisional hernias and ostomy closure. Material and Methods Descriptive study of patients undergoing simultaneous surgery of complex IH repair and intestinal transit reconstruction in the period 2018.2021. All interventions were performed electively and with the collaboration of surgeons experts in abdominal wall and colorectal surgery. Demographic variables, hernias characteristics, surgical techniques, postoperative evolution, morbidity and mortality are recorded Results 16 patients are included. 8 with ileostomy, 3 lateral colostomies and 5 end colostomies . All the patients presented IH of the middle laparotomy and 12 had stomal hernias associated. The mean diameters of the IH were 16.2cm longitudinal and 11cm transverse. Intestinal transit was reconstructed in 15 cases (94%) and incisional hernia repair in 100%. Component separation was required in 75% of cases (8 posterior and 4 anterior). Morbidity in the first postoperative month was 18%, requiring 2 reoperations (12%). At the end of the mean follow-up of 10.8 months, 81% of the cases did not present complications. Conclusions The collaboration between specialist allows the use of advanced techniques in the simultaneous reconstruction of the abdominal wall and intestinal transit, with good clinical results and patient quality of life.

P022 OUTCOMES OF ABDOMINAL WALL REPAIR ASSOCIATED WITH INTESTINAL TRANSIT RECONSTRUCTION SURGERY

Aim Analyze and evaluate the results obtained in patients undergoing transit reconstruction surgery in which an abdominal wall reconstruction (AWR) is associated using a multidisciplinary approach. Material and Methods All patients who underwent an intestinal transit reconstruction associated with an AWR surgery were identified from a prospectively maintained multicenter database. Short and long-term results have been analyzed, especially AWR outcomes. Results 10 patients were identified. 60% were men. Mean time since previous surgery was 1.66 years. 8 cases (80%) associated a midline incisional hernia with the parastomal hernia. 3 (30%) bilateral posterior component separation (PCS) Madrid transverse abdominis muscle release (Madrid TAR) modification, 5 (50%) unilateral Madrid TAR, 1 (10%) PCS Carbonell, and 1 (10%) Rives-Stoppa techniques were performed. A double mesh reconstruction technique was used in 60% of the patients, associating absorbable mesh with a permanent mesh. One patient presented a paucisymptomatic colorectal anastomosis fistula, that could be managed conservatively. A case of postsurgical ileus was also evidenced. Surgical site ocurrences (SSO) were recorded in 4 patients (40%), all of them related to surgical site infection that required a bedside wound opening. During a mean follow-up of 24 (+/- 15) months, there was no evidence of hernia recurrence. No cases of bulging, chronic mesh infection or chronic pain were reported. No case of mortality was recorded in the series. Conclusions Intestinal transit reconstruction surgery associated with an AWR, with a multidisciplinary team managed, presents acceptable long-term results, despite the high SSO associated.

Comparative assessment of the anti-diarrhoeal effects of the ethanol leaf and stem extracts of lantana camara in Wistar rats

The antidiarrhoeal effects of Lantana camara ethanol leaf and stem extracts were compared in Wistar rats. The phytochemical and acute toxicity tests were also determined. The extracts were evaluated for castor oil- induced diarrhoea and enteropooling as well as intestinal transit in rats. The ethanol stem extract produced significant (P < 0.05), while the ethanol leaf extract produced significant (P < 0.01) dose dependent protection on rats against castor oil induced diarrhoea. The stem extract inhibited intestinal transit time and caused significant (P < 0.05), while leaf extract caused significant (P < 0.01) dose related inhibition of castor oil induced enteropooling in rats, comparable to the standard drugs. The leaf and stem extracts significantly and dose dependently delayed the onset of castor oil induced diarrhoea, decreased the frequency of defecation and reduced the severity of diarrhoea in rats. The ethanol leaf and stem extracts of L. camara significantly and dose dependently decreased the volume of intestinal fluid accumulation in the castor oil induced enteropooling. The distance travelled by charcoal meal in intestinal transit time was also reduced. The oral LD50 values obtained were greater than 5000 mg/kg in rats. These findings suggest that both ethanol leaf and stem extracts of Lantana camara may contain some biologically active ingredients that are active for the treatment of diarrhoea in Nigerian herbal traditional medicine. However, the leaf extract has more antidiarrhoeal activities compared to the stem extract in castor oil-induced diarrhoeal in Wistar rats.

Physiological and histopathological effects of electroporation pulse on stomach of rats

Background Irreversible electroporation (IRE) is an emerging tissue ablation technique with widespread potential, especially for cancer treatment. Although the safety and efficacy of IRE for gastric tissue ablation have been demonstrated, there is a gap of knowledge regarding the effect of electroporation pulse (EP) on the physiology and histopathology of the stomach. This study applied EP to the stomach of healthy rats and investigated the digestive function, serum marker levels, and gastric tissue structure of EP-treated rats. Methods Ninety male rats were divided into nine groups and examined up to 28 days post-treatment. A single burst of electroporation pulse (500 V, 99 pluses, 1 Hz, 100 µs) was delivered to the stomachs of rats using a tweezer-style round electrode. Gastric emptying, small intestinal transit, and gastric secretion were measured to evaluate the digestive function. Serum marker levels were determined using ELISA. Haematoxylin–eosin, Masson trichrome, and immunofluorescence were performed for histopathological analysis. Results No significant effect on gastric emptying or secretion was found post-EP, whereas the small intestinal transit decreased at 4 h and rapidly recovered to normal on 1-day post-EP. Further, serum TNF-α and IL-1β levels temporarily changed during the acute phase but returned to baseline within 28 days. Moreover, histopathological analysis revealed that cell death occurred immediately post-EP in the ablation area, whereas the gastric wall scaffold in the ablation region remained intact post-EP. Conclusions This study demonstrates the safety and efficacy of EP on the physiology and histopathology of the stomach and lays a foundation for more comprehensive applications of this technique.

Yeokwisan, a Standardized Herbal Formula, Enhances Gastric Emptying via Modulation of the Ghrelin Pathway in a Loperamide-induced Functional Dyspepsia Mouse Model

Background: Yeokwisan, a standardized herbal formula, has exhibited clinical benefit for patients suffering from refractory functional dyspepsia (FD) in Korea since 2016. However, data about the mechanism of action of this formula are yet not available.Aim of the study: To evaluate and explore the effects of Yeokwisan on gastric emptying, a major symptom of functional dyspepsia, and its underlying mechanisms of action using a mouse model.Materials and methods: BALB/C mice were pretreated with Yeokwisan (100, 200, and 400 mg/kg, po) or mosapride (3 mg/kg, po) for 5 days and then treated with loperamide (10 mg/kg, ip) after 20 h of fasting. A solution of 0.05% phenol red (500 μL) or diet of 5% charcoal (200 μL) was orally administered, followed by assessment of gastric emptying or intestinal transit. Plasma acyl-ghrelin (ELISA), C-kit (immunofluorescence and western blotting), nNOS (western blotting) and gastric contraction- and ghrelin-related gene/protein expression levels were examined in stomach and small intestine tissues.Results: Loperamide injection substantially delayed gastric emptying, while Yeokwisan pretreatment (especially 200 and 400 mg/kg Yeokwisan) significantly attenuated this peristaltic dysfunction, as evidenced by the quantity of phenol red retained in the stomach (p &lt; 0.05 or 0.01) and stomach weight (p &lt; 0.05 or 0.01). The levels of plasma acyl-ghrelin and expression of gastric ghrelin-related genes, such as growth hormone secretagogue receptor (GHSR), ghrelin-O-acyltransferase (GOAT), adrenergic receptor β1 (ADRB1) and somatostatin receptor (SSTR), were significantly normalized (p &lt; 0.05 or 0.01) by Yeokwisan (400 mg/kg). Yeokwisan (400 mg/kg) significantly tempered the loperamide-induced alterations in the c-kit and nNOS levels (p &lt; 0.01) as well as the expression of contraction- and ghrelin-related genes, such as 5-HT4 receptor (5-HT4R), anoctamin-1 (ANO1), ryanodine receptor 3 (RYR3) and smooth muscle myosin light chain kinase (smMLCK), in the stomach, but not in the small intestine.Conclusion: The present results showed the clinical relevance of Yeokwisan, in treating FD, especially in promoting gastric emptying but not small intestinal transit. The main mechanisms corresponding to these effects may involve the modulation of the ghrelin pathway and activation of interstitial cells of Cajal in stomach tissue.

Rotavirus pre-symptomatically downregulates ileum-innervating sympathetic nerves concomitant with increased intestinal transit and altered brain activity

While diarrhea, the hallmark symptom of rotavirus infection, has been considered to occur only due to intrinsic intestinal effects, we show evidence for central control underlying the symptomology. With large-scale 3D volumetric tissue imaging a mouse model, we show that rotavirus infection disrupts the autonomic balance by downregulating the noradrenergic sympathetic nervous system in ileum, concomitant with increased intestinal transit. A most interesting observation was that nervous response from CNS occurs pre-symptomatically, an observation that bring new understanding to how virus give raise to clinical symptoms. In the CNS of infected animals, we found increased pS6 immunoreactivity in the area postrema and decreased phosphorylated STAT5-immunoreactive neurons in the bed nucleus of the stria terminalis, which are associated with autonomic control including stress response. Our observations bring new and important knowledge of how rotavirus virus infection induce gut-nerve-brain crosstalk giving raise to sickness symptoms.