Efficacy and Molecular Mechanism of Quercetin on Constipation Induced by Berberine via Regulating Gut Microbiota.

Berberine (BBR) is used to treat cancer, inflammatory conditions, and so on. But the side effects of BBR causing constipation should not be ignored. In clinical application, the combination of Amomum villosum Lour. (AVL) and BBR can relieve it. However, the effective ingredients and molecular mechanism of AVL in relieving constipation are not clear. A small intestine propulsion experiment was conducted in constipated mice to screen active ingredients of AVL. We further confirmed the molecular mechanism of action of the active ingredient on BBR-induced constipation. Quercetin (QR) was found to be the effective ingredient of AVL in terms of relieving constipation. QR can efficiently regulate the microbiota in mice suffering from constipation. Moreover, QR significantly raised the levels of substance P and motilin while lowering those of 5-hydroxytryptamine and vasoactive intestinal peptide; furthermore, it also increased the protein expression levels of calmodulin, myosin light-chain kinase, and myosin light chain. The use of QR in combination with BBR has an adverse effect-reducing efficacy. The study provides new ideas and possibilities for the treatment of constipation induced by BBR.

Molecular characterization and distribution of motilin and motilin receptor in the Japanese medaka Oryzias latipes.

Motilin (MLN) is a peptide hormone originally isolated from the mucosa of the porcine intestine. Its orthologs have been identified in various vertebrates. Although MLN regulates gastrointestinal motility in tetrapods from amphibians to mammals, recent studies indicate that MLN is not involved in the regulation of isolated intestinal motility in zebrafish, at least in vitro. To determine the unknown function of MLN in teleosts, we examined the expression of MLN and the MLN receptor (MLNR) at the cellular level in Japanese medaka (Oryzias latipes). Quantitative PCR revealed that mln mRNA was limitedly expressed in the gut, whereas mlnr mRNA was not detected in the gut but was expressed in the brain and kidney. By in situ hybridization and immunohistochemistry, mlnr mRNA was detected in the dopaminergic neurons of the area postrema in the brain and the noradrenaline-producing cells in the interrenal gland of the kidney. Furthermore, we observed efferent projections of mlnr-expressing dopaminergic neurons in the lobus vagi (XL) and nucleus motorius nervi vagi (NXm) of the medulla oblongata by establishing a transgenic medaka expressing the enhanced green fluorescence protein driven by the mlnr promoter. The expression of dopamine receptor mRNAs in the XL and cholinergic neurons in NXm was confirmed by in situ hybridization. These results indicate novel sites of MLN activity other than the gastrointestinal tract. MLN may exert central and peripheral actions through the regulation of catecholamine release in medaka.

Motilin, a Novel Orexigenic Factor, Involved in Feeding Regulation in Yangtze Sturgeon (Acipenser dabryanus).

Motilin is a gastrointestinal hormone that is mainly produced in the duodenum of mammals, and it is responsible for regulating appetite. However, the role and expression of motilin are poorly understood during starvation and the weaning stage, which is of great importance in the seeding cultivation of fish. In this study, the sequences of Yangtze sturgeon (Acipenser dabryanus Motilin (AdMotilin)) motilin receptor (AdMotilinR) were cloned and characterized. The results of tissue expression showed that by contrast with mammals, AdMotilin mRNA was richly expressed in the brain, whereas AdMotilinR was highly expressed in the stomach, duodenum, and brain. Weaning from a natural diet of T. Limnodrilus to commercial feed significantly promoted the expression of AdMotilin in the brain during the period from day 1 to day 10, and after re-feeding with T. Limnodrilus the change in expression of AdMotilin was partially reversed. Similarly, it was revealed that fasting increased the expression of AdMotilin in the brain (3 h, 6 h) and duodenum (3 h), and the expression of AdMotilinR in the brain (1 h) in a time-dependent manner. Furthermore, it was observed that peripheral injection of motilin-NH2 increased food intake and the filling index of the digestive tract in the Yangtze sturgeon, which was accompanied by the changes of AdMotilinR and appetite factors expression in the brain (POMC, CART, AGRP, NPY and CCK) and stomach (CCK). These results indicate that motilin acts as an indicator of nutritional status, and also serves as a novel orexigenic factor that stimulates food intake in Acipenser dabryanus. This study lays a strong foundation for the application of motilin as a biomarker in the estimation of hunger in juvenile Acipenser dabryanu during the weaning phase, and enhances the understanding of the role of motilin as a novel regulator of feeding in fish.

Different microbial ecological agents change the composition of intestinal microbiota and the levels of SCFAs in mice to alleviate loperamide-induced constipation.

Probiotics exert beneficial effects by regulating the intestinal microbiota, metabolism, immune function and other ways of their host. Patients with constipation, a common gastrointestinal disorder, experience disturbances in their intestinal microbiota. In the present study, we investigated the effectiveness of two microbial ecological agents (postbiotic extract PE0401 and a combination of postbiotic extract PE0401 and Lacticaseibacillus paracasei CCFM 2711) in regulating the makeup of the intestinal microbiota and alleviating loperamide hydrochloride-induced constipation in mice. We also preliminarily explored the mechanism underlying their effects. Both microbial ecological agents increased the abundance of the beneficial bacteria Lactobacilli and Bifidobacterium after administration and were able to relieve constipation. However, the degree of improvement in constipation symptoms varied depending on the makeup of the supplement. The postbiotic extract PE0401 increased peristalsis time and improved faecal properties throughout the intestinal tract of the host. PE0401 relieved constipation, possibly by modulating the levels of the constipation-related gastrointestinal regulatory transmitters mouse motilin, mouse vasoactive intestinal peptide, and 5-hydoxytryptamine in the intestinal tract of the host and by increasing the levels of the short-chain fatty acids (SCFAs) acetic acid, propionic acid, and isovaleric acid. It also increased the relative abundance of Lactobacillus and Bifidobacterium and reduced that of Faecalibaculum, Mucispirillum, Staphylococcus, and Lachnoclostridium, which are among the beneficial microbiota in the host intestine. Furthermore, PE0401 decreased the levels of constipation-induced host inflammatory factors. Therefore, the two microbial ecological agents can regulate the intestinal microbiota of constipation mice, and PE0401 has a stronger ability to relieve constipation.

The role of free fatty acid receptor-1 in gastric contractions in Suncus murinus.

Motilin is an important hormonal regulator in the migrating motor complex (MMC). Free fatty acid receptor-1 (FFAR1, also known as GPR40) has been reported to stimulate motilin release in human duodenal organoids. However, how FFAR1 regulates gastric motility in vivo is unclear. This study investigated the role of FFAR1 in the regulation of gastric contractions and its possible mechanism of action using Suncus murinus. Firstly, intragastric administration of oleic acid (C18:1, OA), a natural ligand for FFAR1, stimulated phase II-like contractions, followed by phase III-like contractions in the fasted state, and the gastric emptying rate was accelerated. The administration of GW1100, an FFAR1 antagonist, inhibited the effects of OA-induced gastric contractions. Intravenous infusion of a ghrelin receptor antagonist (DLS) or serotonin 4 (5-HT4) receptor antagonist (GR125487) inhibited phase II-like contractions and prolonged the onset of phase III-like contractions induced by OA. MA-2029, a motilin receptor antagonist, delayed the occurrence of phase III-like contractions. In vagotomized suncus, OA did not induce phase II-like contractions. In addition, OA promoted gastric emptying through a vagal pathway during the postprandial period. However, OA did not directly act on the gastric body to induce contractions in vitro. In summary, this study indicates that ghrelin, motilin, 5-HT, and the vagus nerve are involved in the role of FFAR1 regulating MMC. Our findings provide novel evidence for the involvement of nutritional factors in the regulation of gastric motility.

Hormonas gastrointestinales en la estimulación enteral mínima en neonatos prematuros enfermos / Gastrointestinal hormone and minimal enteral feeding in sick premature infants

Objetivo. Medir la respuesta hormonal con estimulación enteral mínima (EEM) en prematuros enfermos. Metología. Fueron 41 pacientes, con peso al nacimiento <1800 g, distribuidos en: grupo I (temprano) con inicio del estímulo en menos de cinco días de edad (n=26), y grupo II (tardío) entre 10 y 14 días (n=15). Se hicieron mediciones basales de cuatro hormonas gastrointestinales (gastrina, PIG, motilina y neurotensina y se inició la estimulación con fórmula para prematuros diluida, comenzando un un mL cada dos horas e incrementando un mL diario hasta alcanzar aproximadamente 120 mL como volumen total, y se registraron las mediciones de las hormonas. Resultados. No hubo diferencia intergrupos en peso, edad gestacional, trofismo y estancia hospitalaria. Hubo diferencias intragrupos entre las mediciones basal y final en todas las hormonas en ambos grupos. Los resultados por subgrupos de edad gestacional (menores y mayores de 32 semanas) y eutróficos e hipotróficos mostraron diferencial basal-final. En relación con peso al nacer y volumen de leche de la EEM, los resultados fueron variables. No hubo complicaciones con el uso del EEM. Conclusiones. El EEM favorece la secreción hormonal gastrointestinal en prematuros enfermos aun administrado tardíamente. El EEM no incrementó las complicaciones abdominales. El peso, la edad gestacional, y el grado trofismo no se asocian a la magnitud de la secreción hormonal