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Nutritional styles as Mediterranean and DASH diets are associated with lower incidences of certain chronic diseases and long life expectancy. The reason lays on their different contribution in fibers, polyphenols (from vegetables and fruit) and proteins. Barley is high fiber cereal that contains high amount of β-glucans and insoluble fibers that it was recognized having healthy benefits. The aim of the study was to evaluate the effects of β-glucans intake on glycaemic response, cholesterol and intestinal hormones levels. A single arm pilot study was performed with ten healthy individual which, consumed pasta enriched with 6% β-glucans for 30 days. Blood was collected at fasting and at multiple intervals until 180 min after the test meal consumption. The results showed that pasta modify plasma levels of gut hormones and low density lipoprotein levels. These results add another piece of evidence to the role of the alimentary interventions to preserve healthy status. [ABSTRACT FROM AUTHOR]

Dietary β-glucans are soluble fibers with potentially health-promoting effects. Gut peptides are important signals in the regulation of energy and glucose homeostasis. This article reviews the effects of different enriched β-glucan food consumption on immune responses, inflammation, gut hormone and cancer. Gut hormones are influenced by enriched β-glucan food consumption and levels of such peptide as YY, ghrelin, glucagon-like peptide 1 and 2 in humans influence serum glucose concentration as well as innate and adaptive immunity. Cancer cell development is also regulated by obesity and glucose dishomeostasy that are influenced by β-glucan food consumption that in turn regulated gut hormones. [ABSTRACT FROM AUTHOR]

Glucagon like peptide-2 (GLP-2) is a gastrointestinal hormone released from enteroendocrine L-type cells together with glucagon like peptide-1 in response to dietary nutrients. GLP-2 acts through a specific receptor, the GLP-2 receptor, mainly located in the gut and in the brain. Classically, GLP-2 is considered a trophic hormone involved in the maintenance of intestinal epithelial morphology and function. This role has been targeted for therapies promoting repair and adaptive growth of the intestinal mucosa. Recently, GLP-2 has been shown to exert beneficial effects on glucose metabolism specially in conditions related to increased uptake of energy, such as obesity. Several actions of GLP-2 are related to a positive energy balance: GLP-2 increases not only the absorptive surface, but also expression and activity of epithelial brush-border nutrient transporters and digestive enzymes, intestinal blood flow, postprandial chylomicron secretion and it inhibits gastrointestinal motility, providing the opportunity to increase absorption of nutrients. Other actions, including anorexigenic effects, appear in opposition to the energy intake. In this review, we discuss the GLP-2 functions related to energy homeostasis. GLP-2 could be considered an hormone causing positive energy balance, which, however has the role to mitigate the metabolic dysfunctions associated with hyper-adiposity. [ABSTRACT FROM AUTHOR]

Neuronostatin is a 13-amino acid peptide encoded by somatostatin gene. It is distributed in different organs including gastrointestinal tract and has been involved in the control of food intake and gastrointestinal motility, likely through an action in the brain. So far, there are no reports about the occurrence of peripheral action sites in the gut. Therefore, the purpose of the present study was to examine, in the mouse, the effects of peripheral administration of neuronostatin on food intake within 24 h and on gastrointestinal motility and to analyse neuronostatin actions on the gastric and intestinal mechanical activity in isolated preparations in vitro. When compared with PBS-treated mice, intraperitoneal neuronostatin reduced food intake in doses ranging from 1 to 15 ng/g b.w. only in the first hour postinjection with a maximum effect obtained at the dose of 15 ng/g b.w. (−46.9%). The peptide (15 ng/g b.w.) significantly reduced gastric emptying rate (−31.1%) and gastrointestinal intestinal transit. Non-amidated neuronostatin failed to affect food intake, gastric emptying and intestinal transit, suggesting the specificity of action. In vitro, neuronostatin induced concentration-dependent gastric relaxation, which was abolished by tetrodotoxin. Neuronostatin failed to affect the spontaneous mechanical activity or the evoked cholinergic contractions in duodenum. These results suggest that exogenous neuronostatin is able to reduce mouse gastric motility by acting peripherally in the stomach, through intramural nervous plexuses. This indirectly action could cause reduction of food intake in the short term. [ABSTRACT FROM AUTHOR]

Glucagon-like peptide 2 [GLP-2] is a 33-amino acid peptide released from the mucosal enteroendocrine L-cells of the intestine. The actions of GLP-2 are transduced by the GLP-2 receptor [GLP-2R], which is localized in the neurons of the enteric nervous system but not in the intestinal epithelium, indicating an indirect mechanism of action. GLP-2 is well known for its trophic role within the intestine and interest in GLP-2 is now reviving based on the approval of the GLP-2R agonist for treatment of short bowel syndrome [SBS]. Recently it also seems to be involved in glucose homeostasis. The aim of this review is to outline the importance of neuroendocrine peptides, specifically of GLP-2 in the enteric modulation of the gastrointestinal function and to focus on new works in order to present an innovative picture of GLP-2. [ABSTRACT FROM AUTHOR]

Abstract: Menthol, the main active constituent of peppermint oil, exerts gut spasmolytic effects, although its mechanism of action remains unclear. We investigated the effects of menthol on gastric emptying and spontaneous- or evoked- mechanical activity of whole murine stomach. Gastric emptying was calculated after i.p. administration of menthol (50mg/Kg). Responses induced by menthol on gastric intraluminal pressure and evoked-cholinergic contractions were analyzed in vitro. Menthol decreased the gastric emptying rate. In vitro, menthol (0.3–30mM) produced a concentration-dependent relaxation of whole stomach, that was significantly reduced by tetrodotoxin or ω-conotoxin GVIA. The gastric relaxant responses were not affected by N ω -nitro-l-arginine methyl ester, inhibitor of nitric oxide-synthase, apamin or [Lys1,Pro2,5,Arg3,4,Tyr6] vasoactive intestinal peptide (VIP)7-28, a VIP receptor antagonist, but they were significantly antagonized by atropine or guanethidine, a blocker of adrenergic neurotransmission. The joint application of atropine and guanethidine did not produce any additive effects on menthol effects. Phentolamine, an α-adrenoceptor antagonist, but not propranolol, a β-adrenoceptor antagonist, significantly reduced menthol responses and the contemporary administration of both adrenergic antagonists did not produce additive effects. Menthol (1–100μM) produced a reduction of the electrically-evoked cholinergic contractions, which was prevented by guanethidine. Menthol did not affect the contractions induced by carbachol. In conclusion, menthol in mouse, is able to reduce the rate of gastric emptying and to relax the stomach in vitro. The latter effect appears due, almost in part, to neural mechanisms, with involvement of α-adrenoceptors leading to reduction of tonic ongoing release of acetylcholine. [Copyright &y& Elsevier]

Abstract: Recently, we have showed that indicaxanthin, the yellow betalain pigment abundant in the fruit of Opuntia ficus indica, has remarkable spasmolytic effects on the intestinal contractility in vitro. Thus, the purpose of the present study was to investigate the mechanism of action underlying the observed response. We used organ bath technique to record the mechanical activity of the mouse ileum longitudinal muscle and ELISA to measure the levels of cAMP. Indicaxanthin induced inhibitory effects on spontaneous mechanical activity, which were unaffected by indomethacin, a non-selective inhibitor of cycloxygenase; 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a selective inhibitor of nitric oxide-dependent guanylyl cyclase; 2′5′dideoxyadenosine, an adenylyl cyclase inhibitor; and zaprinast, a selective inhibitor of the cGMP phosphodiesterase isoenzyme. Indicaxanthin effects were reduced significantly in the presence of 3-isobutyl-1-methylxanthine (IBMX), a non selective inhibitor of phosphodiesterases (PDEs). Indicaxanthin and IBMX significantly reduced the carbachol-evoked contractions and the joint application of both drugs did not produce any additive effect. Indicaxanthin and IBMX increased the inhibitory effects of forskolin, an adenylyl cyclase activator, and the joint application of both drugs did not produce any additive effect. Indicaxanthin, contrarily to IBMX, did not affect the inhibitory action of sodium nitroprusside, a soluble guanylyl cyclase activator. Indicaxanthin increased both basal and forskolin-induced cAMP content of mouse ileal muscle. The present data show that indicaxanthin reduces the contractility of ileal longitudinal muscle by inhibition of PDEs and increase of cAMP concentration and raise the possibility of using indicaxanthin in the treatment of motility disorders, such as abdominal cramps. [Copyright &y& Elsevier]

Abstract: The purpose of the present study was to examine whether cannabinoid receptor agonists influence spontaneous contractile activity of longitudinal muscle in mouse ileum in vitro. Isolated segments of mouse ileum displayed spontaneous contractions with an amplitude and frequency of about 300 mg and 30 cpm, respectively. The endocannabinoid anandamide (1–100 μM), the selective cannabinoid CB1 receptor agonist, ACEA (0.1 μM–10 μM), but not the selective cannabinoid CB2 receptor agonist, JWH 133 (0.1 μM–10 μM), reduced in a concentration-dependent manner the spontaneous mechanical activity. The inhibitory effect consisted in a decrease of the mean amplitude of longitudinal spontaneous contractions, without changes in the resting tone. The inhibitory effect induced by cannabinoids was significantly antagonized by the selective cannabinoid CB1 receptor antagonist, SR141716A (0.1 μM), but not by the selective cannabinoid CB2 receptor antagonist, AM630 (0.1 μM). None of the cannabinoid antagonists, at the concentration used, did affect the spontaneous mechanical activity. The ACEA-induced reduction of spontaneous contractions was almost abolished by tetrodotoxin, atropine or apamin and it was unaffected by hexamethonium or N ω-nitro-l-arginine methyl ester (l-NAME), inhibitor of nitric oxide synthase. The myogenic contractions evoked by carbachol were not affected by ACEA. In conclusion, the present results suggest that activation of neural cannabinoid CB1 receptors may play a role in the control of spontaneous mechanical activity through inhibition of acetylcholine release from cholinergic nerve. Activation of small conductance Ca2+-dependent K+ channels is involved in this action. [Copyright &y& Elsevier]

Abstract: Glucagon-like peptide-2 (GLP-2) is a nutrient-responsive gut hormone that increases the intestinal absorption. Exogenous GLP-2 also induces gastric fundus relaxation with possible implications for emptying rate or feeling of satiety. GLP-2 actions are mediated by GLP-2 receptor (GLP-2R), located on enteric neurons and myofibroblasts in murine gastrointestinal tract. Because it is not known whether changes in the endogenous GLP-2R levels occur in different nutritional states, we examined the GLP-2R gene and protein expression in gastric fundus from standard diet (STD)-fed, 12-h and 24-h fasted and re-fed, or high-fat diet (HFD)-fed mice and we analyzed the mechanical responses to exogenous GLP-2 in the stomach from different groups of animals. GLP-2 expression was examined using real-time reverse-transcription polymerase chain reaction and western blotting. The gastric mechanical activity from whole-organ was recorded in vitro as changes of intraluminal pressure. GLP-2R expression in fundic region from 12-h or 24-h fasted mice was reduced in comparison with STD-fed animals and returned to control values in re-fed mice, while it was increased in HFD-fed mice. The exogenous GLP-2 efficacy in inducing gastric relaxation, normalized to isoproterenol response, was decreased in stomach from fasted mice and it was increased in stomach from HFD-fed mice in comparison with STD-fed mice. In conclusion, the nutritional state influences GLP-2R expression in murine gastric preparations. The changes in the GLP-2R expression are associated with modifications of GLP-2 gastric relaxant efficacy. This could represent an adaptive response to reduced or increased nutrient intake. [Copyright &y& Elsevier]

Abstract Nonsense mutations in the CFTR gene prematurely terminate translation of the CFTR mRNA leading to the production of a truncated protein that lacks normal function causing a more severe form of the cystic fibrosis (CF) disease. About 10% of patients affected by CF show a nonsense mutation. A potential treatment of this alteration is to promote translational readthrough of premature termination codons (PTCs) by Translational Readthrough Inducing Drugs (TRIDs) such as PTC124. In this context we aimed to compare the activity of PTC124 with analogues differing in the heteroatoms position in the central heterocyclic core. By a validated protocol consisting of computational screening, synthesis and biological tests we identified a new small molecule (NV2445) with 1,3,4-oxadiazole core showing a high readthrough activity. Moreover, we evaluated the CFTR functionality after NV2445 treatment in CF model systems and in cells expressing a nonsense- CFTR-mRNA. Finally, we studied the supramolecular interactions between TRIDs and CFTR-mRNA to assess the biological target/mechanism and compared the predicted ADME properties of NV2445 and PTC124. Graphical abstract Image 1 Highlights • Nonsense mutations originate premature termination codons (PTC) in the mRNA. • PTC are responsible for the production of a not-functional truncated protein. • Translational readthrough inducing drugs (TRIDs) rescue protein production. • CFTR production and functionality can be restored by TRIDs. • Oxadiazoles are small non-toxic molecules with readthrough activity. [ABSTRACT FROM AUTHOR]

Abstract: Glucagon-like-peptide-1 (GLP-1) is a proglucagon-derived peptide expressed in the intestinal enteroendocrine-L cells and released after meal ingestion. GLP-1 reduces postprandial glycemia not only by its hormonal effects, but also by its inhibitory effects on gastrointestinal motility. Recently, we showed that GLP-1 acts in the enteric nervous system of mouse intestine. Therefore our working hypothesis was that GLP-1 may have also a direct influence on the gastric mechanical activity since the major part of experimental studies about its involvement in the regulation of gastric motility have been conducted in in vivo conditions. The purposes of this study were (i) to examine exogenous GLP-1 effects on mouse gastric mechanical activity using isolated whole stomach; (ii) to clarify the regional activity of GLP-1 using circular muscular strips from gastric fundus or antrum; (iii) to analyze the mechanism of action underlying the observed effects; (iv) to verify regional differences of GLP-1 receptors (GLP-1R) expression by RT-PCR. In the whole stomach GLP-1 caused concentration-dependent relaxation significantly anatagonized by exendin (9–39), an antagonist of GLP-1R and abolished by tetrodotoxin (TTX) or Nω-nitro-l-arginine methyl ester (l-NAME), inhibitor of nitric oxide (NO) synthase. GLP-1 was without any effect in fundic strips, but it induced concentration-dependent relaxation in carbachol-precontracted antral strips. The effect was abolished by TTX or l-NAME. RT-PCR analysis revealed a higher expression of GLP-1R mRNA in antrum than in fundus. These results suggest that exogenous GLP-1 is able to reduce mouse gastric motility by acting peripherally in the antral region, through neural NO release. [ABSTRACT FROM AUTHOR]