Effects of the algae derivatives on performance, intestinal histomorphology, ileal microflora, and egg yolk biochemistry of laying Japanese quail.

We examined the effect of the Persian Gulf algae derivates, phycocyanin (PC) and fucoidan (FUC), on production performance, egg quality, intestinal histomorphology, ileal microflora, and egg yolk biochemistry of laying Japanese quail. A total of 250 six-wk-old Japanese quails with an average body weight of 215 ± 10 g were allocated to 5 treatments, 5 replicates and 10 birds in each replicate in a completely randomized design. The treatment groups received PC (from Spirulina platensis) and FUC (from brown seaweed) in their drinking water while control groups did not. Treatment groups received PC and FUC at 20 or 40 mg/L levels (denoted as PC20, PC40, FUC20, and FUC40, respectively). All birds were fed the same diet. All treatments significantly improved the percentage of hen day egg production (HDEP) (P = 0.002), egg mass (P = 0.002), and feed conversion ratio (FCR) (P = 0.022) but no difference was noted in egg weight (EW) and feed intake (FI). Different levels of PC and FUC significantly increased the thickness of eggshells (P = 0.022); however, the weight of the digestive tract (liver, spleen, proventriculus, gizzard, and pancreas) and oviduct was not affected. Algal derivates improved the villus height (P = 0.007) and crypt depth (P = 0.007) of the duodenum, as well as, the villus height (P = 0.005) and crypt depth (P = 0.026) of the jejunum. Both algal derivates positively affected the intestinal microflora (populations of Lactobacillus (P = 0.017), Coliform (P = 0.005), and Clostridium (P = 0.000)) whereas aerobic bacteria were unaffected. Yolk cholesterol P = 0.012) and yolk malondialdehyde P = 0.050) content were significantly reduced in experimental treatments compared to the control group. In conclusion, our results showed that the treatment of laying Japanese quails with algal derivates positively affects quail performance, intestinal morphology, intestinal microflora, and yolk cholesterol and malondialdehyde. Additional studies exploring optimal dosages and mechanisms of action is warranted to fully understand the scope of the algae derivates in poultry production.

Curcumin attenuates aflatoxin B1-induced ileum injury in ducks by inhibiting NLRP3 inflammasome and regulating TLR4/NF-κB signaling pathway.

Aflatoxin B1 (AFB1) is a widespread toxic contamination in feed for animals. The primary active component of turmeric, curcumin (Cur), is an antioxidant and an anti-inflammatory. However, it is yet unknown how AFB1 affects the intestinal epithelial barrier and whether Cur acts as a protective mechanism when exposed to AFB1. Here, we explored the mechanism of AFB1-induced intestinal injury from intestinal epithelial barrier, inflammation, pyroptosis, and intestinal flora, and evaluated the protective role of Cur. We found that AFB1 caused weight loss and intestinal morphological damage that is mainly characterized by shortened intestinal villi, deepened crypts, and damaged intestinal epithelium. Exposure to AFB1 decreased the expression of Claudin-1, MUC2, ZO-1, and Occludin and increased the expression of pyroptosis-related factors (NLRP3, GSDMD, Caspase-1, IL-1ß, and IL-18) and inflammation-related factors (TLR4, NF-κB, IκB, IFN-γ, and TNF-α). Furthermore, ileal gut microbiota was altered, and simultaneously, the Lactobacillus abundance was decreased. The gut microbiota interacts with a wide range of physiologic functions and disease development in the host through its metabolites, and disturbances in gut microbial metabolism can cause functional impairment of the ileum. Meanwhile, Cur can ameliorate histological ileum injuries and intestinal flora disturbance caused by AFB1. We found that Cur reversed the effects of AFB1 through modulating both NLRP3 inflammasome and the TLR4/NF-κB signaling pathway. In conclusion, AFB1 can induce inflammatory damage and pyroptosis in duck ileum, while Cur has obviously protective effects on all the above damages.

Colchicine disrupts bile acid metabolic homeostasis by affecting the enterohepatic circulation in mice.

Although the medicinal properties of colchicine (COL) have been widely known for centuries, its toxicity has been the subject of controversy. The narrow therapeutic window causes COL to induce gastrointestinal adverse effects even when taken at recommended doses, mainly manifested as nausea, vomiting, and diarrhea. However, the mechanism of COL-induced gastrointestinal toxic reactions remains obscure. In the present study, the mice were dosed with COL (2.5 mg/kg b.w./day) for a week to explore the effect of COL on bile acid metabolism and the mechanism of COL-induced diarrhea. The results showed that COL treatment affected liver biochemistry in mice, resulting in a significant down-regulation of the mRNA expression levels of bile acid biosynthesis regulators Cyp7a1, Cyp8b1, Cyp7b1, and Cyp27a1 in liver tissues. The mRNA expression levels of bile acid transporters Ntcp, Oatp1, Mrp2, Ibabp, Mrp3, Osta, and Ostb in liver and ileum tissues were also significantly down-regulated. In addition, COL treatment significantly inhibited the mRNA expression levels of Fxr and its downstream target genes Shp, Lrh1, and Fgf15 in liver and ileum tissues, affecting the feedback regulation of bile acid biosynthesis. More importantly, the inhibition of COL on bile acid transporters in ileal and hepatic tissues affected bile acid recycling in the ileum as well as their reuptake in the liver, leading to a significantly increased accumulation of bile acids in the colon, which may be an important cause of diarrhea. In conclusion, our study revealed that COL treatment affected bile acid biosynthesis and enterohepatic circulation, thereby disrupting bile acid metabolic homeostasis in mice.

Butyrate acts as a positive allosteric modulator of the 5-HT transporter to decrease availability of 5-HT in the ileum.

BACKGROUND AND PURPOSE: Radiation therapy-induced gastrointestinal distress is partly associated with the elimination of gut microbiota. The effectiveness of 5-HT receptor antagonists to treat radiation therapy-induced emesis implies a pathophysiological role of 5-HT. Peripheral 5-HT is derived from intestinal epithelium. We have investigated the role of gut microbiota in regulating intestinal 5-HT availability. EXPERIMENTAL APPROACH: A radiation therapy murine model accompanied by faecal microbiota transplantation from donors fed different diets was investigated, and mouse ileal organoids were used for mechanistic studies. The clinical relevance was validated by a small-scale human study. KEY RESULTS: Short-term high-fat diet (HFD) induced gut bacteria to produce butyrate. Irradiated mice receiving HFD-induced microbiome had the lowest ileal levels of 5-HT, compared with other recipients. Treatment with butyrate increased 5-HT uptake in mouse ileal organoids, assayed by the real-time tracking of a fluorescent substrate for monoamine transporters. Silencing the 5-HT transporter (SERT) in the organoids abolished butyrate-stimulated 5-HT uptake. The competitive tests using different types of selective 5-HT reuptake inhibitors suggested that butyrate acted as a positive allosteric modulator of SERT. In human gut microbiota, butyrate production was associated with the interconversion between acetate and butyrate. Faecal contents of both acetate and butyrate were negatively associated with serum 5-HT, but only butyrate was positively correlated with body mass index in humans. CONCLUSION AND IMPLICATIONS: Short-term HFD may be beneficial for alleviating gastrointestinal reactions by increasing butyrate to suppress local 5-HT levels and providing energy to cancer patients given radiation therapy.

Red osier dogwood extract vs. trimethoprim-sulfadiazine (Part 2). Pharmacodynamic effects on ileal and cecal microbiota of broiler chickens challenged orally with Salmonella Enteritidis.

With the subsisting restrictions on the use of antibiotics in poultry production, the use of plant extracts has shown some promising antimicrobial capacity similar to antibiotics; however, such capacity is largely dependent on their total polyphenol concentration and profile. Given the emerging antimicrobial potential of red osier dogwood (ROD) extract, the study aimed to investigate the pharmacodynamic effect of ROD extract on the ileal and cecal microbiota of broiler chickens challenged orally with Salmonella Enteritidis (SE). A 21 d 4 × 2 factorial experiment was conducted based on 2 main factors, including diets and SE challenge. A total of 384 one-day-old mixed-sex Cobb-500 broiler chicks were randomly allotted to 4 dietary treatments; Negative control (NC), NC + 0.075 mg trimethoprim-sulfadiazine (TMP/SDZ)/kg of diet, and NC containing either 0.3 or 0.5% ROD extract. On d 1, half of the birds were orally challenged with 0.5 mL of phosphate-buffered saline (Noninfected group) and the remaining half with 0.5 mL of 3.1 × 105 CFU/mL SE (Infected group). Dietary treatments were randomly assigned to 8 replicate cages at 6 birds/cage. On d 21, 10 birds/treatment were euthanized and eviscerated to collect ileal and cecal digesta for gut microbiota analysis. The ileal and cecal microbiota was dominated by phyla Firmicutes, Proteobacteria, and Actinobacteriota. The SE infection decreased (P < 0.05) the relative abundance of Proteobacteria and Actinobacteriota in the ileum and ceca, respectively, however, it increased (P < 0.05) Proteobacteria in the ceca. Both 0.3 and 0.5% ROD extracts (P < 0.05) depressed the relative abundance of Actinobacteriota in the ileum but marginally improved (P < 0.05) it in the ceca compared to the TMP/SDZ treatment. Dietary TMP/SDZ increased (P < 0.05) genus Bifidobacterium at the ileal and cecal segments compared to other treatments. Dietary 0.3 and 0.5% marginally improved (P < 0.05) Bifidobacterium in the ceca and depressed (P < 0.05) Weissella and was comparably similar to TMP/SDZ in the ileum. Regardless of the dietary treatments and SE infection, alpha diversity differed (P < 0.05) between ileal and cecal microbiota. Beta diversity was distinct (P < 0.05) in both ileal and cecal digesta along the SE infection model. Conclusively, both ROD extract levels yielded a pharmacodynamic effect similar to antibiotics on ileal and cecal microbiota.

Oral administration of Lactobacillus delbrueckii enhances intestinal immunity through inducing dendritic cell activation in suckling piglets.

Lactobacillus delbrueckii (LAB) has been demonstrated to exert versatile beneficial effects on modulating intestinal immunity, increasing gut microbial diversity, promoting growth performance, and even preventing disease onset in pigs. However, the underlying mechanism of LAB-mediated gut immunity regulation in piglets remains unclear. In this study, we found that supplementation of LAB significantly increases serum TNF-α, ileum IL-4, and IL-10 levels compared with the control group. Meanwhile, oral supplementation of LAB-modified gut microbial communities was evidenced by the increased abundance of the Lactobacillus genus in the colon. Mechanistically, LAB induced dendritic cell (DC) maturation and activation, which may be relevant to the activation of NF-κB and MAPK signaling pathways. Moreover, we found that oral administration of LAB during the suckling period shows long-lasting immunomodulatory impacts on intestinal immunity after weaning. Collectively, this study uncovers the mechanism of LAB in regulating the intestinal immunity of piglets, suggesting that LAB can be developed as an immunoenhancing biological agent during the suckling period.

Effect of Heat-Treated Garlic (Allium sativum L.) on Growth Parameters, Plasma Lipid Profile and Histological Changes in the Ileum of Atherogenic Rats.

Dietary supplementation with raw garlic has a preventive and healing effect in cardiovascular diseases, but it could also damage the intestinal mucosa, resulting in impairment of nutrient absorption. Garlic processing, including heat treatment, changes the content and biological activity of garlic, so it is crucial to find food-processing methods that will preserve the health-promoting properties of garlic while minimizing its negative impact on the digestive system. Therefore, in this study, the effect of garlic (Allium sativum L.) on growth parameters, plasma lipid profile, and morphological parameters in the ileum of Wistar rats subjected to various types of heat treatment (90 s blanching garlic, 10 min boiling in water, 10 min pan frying without fat, microwave heating fresh garlic, 90 s blanching and microwave heating garlic, 10 min boiling in water and microwave heating garlic, and 10 min pan frying without fat and microwave heating garlic) was determined in an atherogenic diet (containing 1% addition of cholesterol). In the conducted research, it was found that the diet supplemented with heat-treated garlic used in the atherogenic diet improved the consumption and growth parameters of rats, depending on the type and time of its use. The highest consumption was recorded in atherogenic groups supplemented with garlic subjected to a longer (10 min) heat treatment and was then heated in a microwave oven. Garlic subjected to the shortest heat treatment proved to be most effective, and a significant improvement in the lipid profiles of rats' plasma with atherogenic was observed. Extending the time of heat treatment of garlic and, additionally, its microwaving significantly weakened the action of garlic in the body, but still retained its hypolipidemic effect. The greatest influence on the structural changes in the mucosa of the rats' iliac intestine, manifested by degeneration of the mucosa, shortening the length of the intestinal villi, damage to the brush border, and thus impairment of the intestinal absorption, was exerted by supplementing the atherogenic diet with garlic subjected to short-term heat treatment. Among the processes used, blanching was the least favorable, and the long-lasting thermal processes (cooking, frying for 10 min) had a positive effect on the mucosa of the rats' intestines. The results obtained in this study confirm that the selection of an appropriate method of thermal processing of garlic may allow for the maintenance of preventive and therapeutic efficacy of garlic in cardiovascular diseases, while ensuring the safety of its long-term use in the context of degenerative changes in the gastrointestinal tract.

Lemon balm (Melissa officinalis L.) essential oil and citronellal modulate anxiety-related symptoms - In vitro and in vivo studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Besides psyche-related symptoms, patients with anxiety disorders can have a large number of somatic symptoms as well. Although the treatment of these disorders is mainly focused on resolving their mental component, one cannot neglect the need for the treatment of accompanying somatic symptoms. Melissa officinalis L. (lemon balm), in various formulations, has been extensively used as an ethnomedicinal remedy for the treatment of different psyche-related symptoms, and its use is considered relatively safe. AIM OF THE STUDY: In the present study, the activity of M. officinalis (MO) essential oil was evaluated in several in vitro and in vivo models mimicking or involving anxiety-related somatic symptoms. MATERIALS AND METHODS: To address the effect of MO essential oil on the gastrointestinal and heart-related symptoms accompanying anxiety disorders, in vitro models were utilized that follow the function of the isolated mouse ileum and atria tissues, respectively, after exposure to MO essential oil. Effects of MO essential oil on BALB/c mice motor activity was estimated using the open field, rota-rod, and horizontal wire tests. Additionally, the essential oil was assayed for its potential in inhibiting acetylcholinesterase activity. RESULTS: The performance of mice treated with 25 mg/kg of the oil showed a statistically significant decrease in the motor impairment arising from acute anxiety (open field test), while there was a prolonged latency and a reduction of the frequency of falling from a rotating rod and/or a horizontal wire (signs of muscle weakness/spasms). Concentrations of the essential oil higher than 1 µg/mL were found to inhibit both spontaneous and induced ileum contractions. Moreover, the essential oil and citronellal were found to decrease isolated mouse atria contraction frequency, as well as contraction force. However, the oil was found to be a very weak acetylcholinesterase inhibitor. CONCLUSION: The modulation of anxiety-related symptoms by the oil was found not to be mediated through the inhibition of the acetylcholinesterase, nonetheless, the mechanistic studies involving the ileum and cardiac tissues, revealed that the activity of MO and citronellal might be related to the modification of either voltage-gated Ca2+ channels or muscarinic receptors. Mice locomotion, balance, and muscle strength were not impacted by the essential oil; however, its main constituent, citronellal, was found to exert a certain degree of muscle function inhibition. All these results suggest that the activity of MO essential oil arises from synergistic and/or antagonistic interactions of its constituents, and is not completely dependent on the oil's main constituent.

Minimum biological domain of xenin-25 required to induce anion secretion in the rat ileum.

Xenin-25 has a variety of physiological functions in the gastrointestinal tract, including ion transport and motility. Xenin-25 and neurotensin show sequence homology, especially near their C-terminal regions. The sequence similarity between xenin-25 and neurotensin indicates that the effects of xenin-25 is mediated by the neurotensin receptor but some biological actions of xenin-25 are independent. We have previously reported that xenin-25 modulates intestinal ion transport and colonic smooth muscle activity. However, minimal biological domain of xenin-25 to induce ion transport was not clear. To improve the mechanistic understanding of xenin-25 and to gain additional insights into the functions of xenin-25, the present study was designed to determine the minimal biological domain of xenin-25 required for ion transport in the rat ileum using various truncated xenin fragments and analogues in an Ussing chamber system. The present results demonstrate that the minimum biological domain of xenin-25 to induce Cl-/HCO3- secretion in the ileum contains the C-terminal pentapeptide. Furthermore, Arg at position 21 is important to retain the biological activity of xenin-25 and induces Cl-/HCO3- secretion in the rat ileum.

NPC1L1 Deficiency Suppresses Ileal Fibroblast Growth Factor 15 Expression and Increases Bile Acid Pool Size in High-Fat-Diet-Fed Mice.

Niemann-Pick C1-like 1 (NPC1L1) mediates intestinal uptake of dietary and biliary cholesterol and is the target of ezetimibe, a cholesterol absorption inhibitor used to treat hypercholesterolemia. Genetic deletion of NPC1L1 or ezetimibe treatment protects mice from high-fat diet (HFD)-induced obesity; however, the molecular mechanisms responsible for this therapeutic benefit remain unknown. A major metabolic fate of cholesterol is its conversion to bile acids. We found that NPC1L1 knockout (L1-KO) mice fed an HFD had increased energy expenditure, bile acid pool size, and fecal bile acid excretion rates. The elevated bile acid pool in the HFD-fed L1-KO mice was enriched with tauro-ß-muricholic acid. These changes in the L1-KO mice were associated with reduced ileal mRNA expression of fibroblast growth factor 15 (FGF15) and increased hepatic mRNA expression of cholesterol 7α-hydroxylase (Cyp7A1) and mitochondrial sterol 27-hydroxylase (Cyp27A1). In addition, mRNA expression of the membrane bile acid receptor Takeda G protein-coupled receptor 5 (TGR5) and type 2 iodothyronine deiodinase (Dio2) were elevated in brown adipose tissue of L1-KO mice, which is known to promote energy expenditure. Thus, altered bile acid homeostasis and signaling may play a role in protecting L1-KO mice against HFD-induced obesity.

Lactobacillus johnsonii 3-1 and Lactobacillus crispatus 7-4 promote the growth performance and ileum development and participate in lipid metabolism of broilers.

Long-term use of antibiotic growth promoter (AGP) in animal production is the main cause of antimicrobial resistance of pathogenic bacteria. Therefore, seeking alternatives to AGP is crucial for animal husbandry. Among all AGP alternatives, probiotics are promising candidates. In this study, two strains of lactic acid bacteria, L. johnsonii 3-1 and L. crispatus 7-4, were isolated from the feces of wild Gallus gallus, which exhibited obvious anti-pathogenic activity and improved the growth performance of broilers. Furthermore, we found that these two strains participated in the lipid metabolism of broilers by reducing the content of TC and TG in ileal epithelial cells and up-regulating the liver AMPKα/PPARα/CPT-1 pathway, which affects abdominal fat deposition. In summary, L. johnsonii 3-1 and L. crispatus 7-4 have the potential to be used as AGP substitutes and participate in the lipid metabolism of broilers to reduce abdominal fat deposition. Importantly, our study reveals for the first time that L. crispatus participates in liver lipid metabolism to reduce abdominal fat deposition in broilers.

Development of a self-limiting model of methotrexate-induced mucositis reinforces butyrate as a potential therapy.

Gastrointestinal mucositis is a complication of anticancer treatment, with few validated in vitro systems suitable to study the complex mechanisms of mucosal injury. Therefore, we aimed to develop and characterize a chemotherapeutic-induced model of mucositis using 3D intestinal organoids. Organoids derived from mouse ileum were grown for 7 days and incubated with different concentrations of the chemotherapeutic agent methotrexate (MTX). Metabolic activity, citrulline levels and cytokine/chemokine production were measured to determine the optimal dosage and incubation time. The protective effects of folinic acid on the toxicity of MTX were investigated by pre-treating organoids with (0.0005-50 µg/mL) folinic acid. The impact of microbial-derived short-chain fatty acids was evaluated by supplementation with butyrate in the organoid model. MTX caused a dose-dependent reduction in cell metabolic activity and citrulline production that was salvaged by folinic acid treatment. Overall, MTX causes significant organoid damage, which can be reversed upon removal of MTX. The protective effect of folinic acid suggest that the organoids respond in a clinical relevant manner. By using the model for intervention, it was found that prophylactic treatment with butyrate might be a valuable strategy for prophylactic mucositis prevention.

Calcium-sensing receptor (CaSR) agonist R568 inhibits small intestinal motility of mice through neural and non-neural mechanisms.

Gastrointestinal motility (GI) disorder causes symptoms such as dyspepsia, abdominal distention, and constipation and severely affects quality of life. The calcium (Ca2+)-sensing receptor (CaSR) expressed in the digestive tract can be activated by amino acids and participates in GI motility regulation. This study is designed to explore the effect and underlying mechanism of CaSR agonist R568 on the small intestine motility of mice in vivo and ex vivo. R568 was given to male C57BL/6 mice by gavage or incubated with isolated jejunum and ileum segments to observe its effects on GI motility and the involved neurons, neurotransmitters and hormones were detected by fluorescence immunohistochemistry and enzyme-linked immunosorbent assays. The in vivo results showed that the intestinal propulsive rate reduced in response to oral intake of R568. R568 treatment increased the numbers of nitric oxide synthase-positive neurons and nitric oxide release but decreased the choline acetyl transferase-positive neurons and acetylcholine release in the myenteric plexuses. R568 increased the secretion of cholecystokinin in the intestinal tissues and serum but had no effect on the secretion of glucagon like peptide-1. Ex vivo results showed that R568 inhibited the contractility of intestinal strips from the jejunum and ileum. Nitric oxide synthase (NOS) inhibitor L-nitroarginine methyl ester (L-NAME), M-receptor antagonist-atropine, and tetrodotoxin (TTX) failed to block the effect of R568. CaSR co-expressed with interstitial cells of Cajal (ICCs) in the myenteric plexus suggests the possibility that ICCs mediated the effect of R568. Our findings demonstrate that CaSR activation inhibited intestinal motility, and both the enteric nervous system and non-neural mechanism are involved in this process.

Cholesterol-lowering effects of taurine through the reduction of ileal FXR signaling due to the alteration of ileal bile acid composition.

Studies using animal models of hypercholesterolemia have established that taurine reduces cholesterol levels; however, the precise mechanism underlying this cholesterol-lowering effect is unclear. This study addressed this issue by investigating whether bile acid/farnesoid X receptor (FXR) signaling is involved in taurine-mediated cholesterol-lowering effect. Fxr-null and wild-type mice were administered 2% (w/v) taurine in their drinking water and fed a control diet or control diet supplemented with 1% (w/w) cholesterol (cholesterol diet) for 10 days. Taurine intake did not significantly alter hepatic and serum total cholesterol (TC) levels and bile acid compositions of the liver and intestinal lumen in Fxr-null and wild-type mice fed the control diet. By changing to a cholesterol diet, taurine intake significantly decreased hepatic and serum cholesterol levels in wild-type mice. In contrast, it significantly decreased hepatic, not serum, cholesterol levels in Fxr-null mice. Taurine intake significantly altered the bile acid composition of the intestinal lumen in wild-type mice fed a cholesterol diet, but not in Fxr-null mice. An increase in FXR antagonistic bile acids was detected in the intestinal lumen of taurine-treated wild-type mice fed a cholesterol diet. Taurine intake reduced the ileal expression of FXR target genes fibroblast growth factor 15 (Fgf15) and small heterodimer partner (Shp). In contrast, it enhanced the hepatic expression of cholesterol 7α-hydroxylase (Cyp7a1) in wild-type mice fed a cholesterol diet, but not in Fxr-null mice. These results suggest that taurine is partially involved in cholesterol lowering by reducing the ileal FXR signaling due to the alteration of ileal bile acid composition.

Influence of Tilia tomentosa Moench Extract on Mouse Small Intestine Neuromuscular Contractility.

Functional gastrointestinal disorders (FGIDs) are characterized by abdominal pain, bloating and bowel disturbances. FGID therapy is primarily symptomatic, including treatment with herbal remedies. Flower extract of Tilia tomentosa Moench (TtM) is occasionally used as an anti-spasmodic in popular medicine. Since its effect on intestinal response is unknown, we evaluated the influence of TtM extract on small intestine contractility. Ileal preparations from C57BL/6J mice were mounted in organ baths to assess changes in muscle tension, following addition of TtM extract (0.5-36 µg/mL) or a vehicle (ethanol). Changes in contractile response to receptor- and non-receptor-mediated stimuli were assessed in ileal preparations pretreated with 12 µg/mL TtM. Alterations in the enteric nervous system neuroglial network were analyzed by confocal immunofluorescence. Increasing addition of TtM induced a marked relaxation in ileal specimens compared to the vehicle. Pretreatment with TtM affected cholinergic and tachykininergic neuromuscular contractions as well as K+-induced smooth muscle depolarization. Following incubation with TtM, a significant reduction in non-adrenergic non-cholinergic-mediated relaxation sensitive to Nω-Nitro-L-arginine methyl ester hydrochloride (pan-nitric oxide synthase inhibitor) was found. In vitro incubation of intestinal specimens with TtM did not affect the myenteric plexus neuroglial network. Our findings show that TtM-induced intestinal relaxation is mediated by nitric oxide pathways, providing a pharmacological basis for the use of TtM in FGIDs.

Impacts of Fructose on Intestinal Barrier Function, Inflammation and Microbiota in a Piglet Model.

The metabolic disorder caused by excessive fructose intake was reported extensively and often accompanied by intestinal barrier dysfunction. And the rising dietary fructose was consumed at an early age of human. However, related researches were almost conducted in rodent models, while in the anatomy and physiology of gastrointestinal tract, pig is more similar to human beings than rodents. Hence, weaned piglets were chosen as the model animals in our study to investigate the fructose's impacts on intestinal tight junction, inflammation response and microbiota structure of piglets. Herein, growth performance, inflammatory response, oxidation resistance and ileal and colonic microbiota of piglet were detected after 35-day fructose supplementation. Our results showed decreased tight junction gene expressions in piglets after fructose addition, with no obvious changes in the growth performance, antioxidant resistance and inflammatory response. Moreover, fructose supplementation differently modified the microbiota structures in ileum and colon. In ileum, the proportions of Streptococcus and Faecalibacterium were higher in Fru group (fructose supplementation). In colon, the proportions of Blautia and Clostridium sensu stricto 1 were higher in Fru group. All the results suggested that tight junction dysfunction might be an earlier fructose-induced event than inflammatory response and oxidant stress and that altered microbes in ileum and colon might be the potential candidates to alleviate fructose-induced intestinal permeability alteration.

Alterations in MAdCAM1-Positive Mucosal Capillaries and Integrin a4b7-Positive Lymphocytes in Crohn's Disease Treated with Anti-TNFα Biologics.

OBJECTIVE: To elucidate the reasons for the decreased effectiveness of Vedolizumab (VDZ) treatment in patients with Crohn's disease (CD) previously treated (CD-T) with anti-TNF-α biologics. METHODS: Immunohistochemical staining was performed on sections of formalin-fixed paraffin-embedded ileocolonic biopsies using antibodies for the mucosal addressin molecule (MAdCAM-1) and Etrolizumab. RESULTS: The mean number of MAdCAM-1 positive capillaries (MAdCAM-1-C) was 3 in controls, 8.5 in CD, 5.37 in CD-T, 5.7 in ulcerative colitis (UC), and 3.1 in lymphocytic colitis (LC) (p=0.0032). When all biopsies with inflammatory bowel disease (IBD) in this series were considered together, the number of MAdCAM-1-C increased with an increased histologic activity score (HAS) (p<0.001). The mean MAd-CAM-1-C was lower in CD-T than CD (5.37 vs. 8.5, p=0.0362), even in cases with high HAS (6.46 vs. 9.5, p=0.073). Two of 6 (33%) controls, 4 of 6 (67%) CD, 9 of 16 (56%) CD-T, 6 of 7 (86%) UC, and 0 of 8 (0%) LC showed Etrolizumab-positive lymphocytes (E-Ly, p=0.0106). IBD biopsies positive for E-Ly were associated with higher HAS (p=0.0546). MAdCAM-1-C was heterogenous in some IBD cases. CONCLUSIONS: Our results suggest that treatment with anti-TNF-α reduces the number of MAdCAM-1-C in CD, even in biopsies with high HAS. This suggests that high inflammation in such cases obviously failed to respond to anti-TNF-α, may be less dependent on the migration of a4b7-lymphocytes to the inflamed mucosa, and therefore may not optimally respond to VDZ treatment.Presented in part at the Digestive Diseases Week meeting, San Diego, CA, May 2019. Supported by Takeda Pharmaceuticals.

Antispasmodic Effect of Asperidine B, a Pyrrolidine Derivative, through Inhibition of L-Type Ca2+ Channel in Rat Ileal Smooth Muscle.

Antispasmodic agents are used for modulating gastrointestinal motility. Several compounds isolated from terrestrial plants have antispasmodic properties. This study aimed to explore the inhibitory effect of the pyrrolidine derivative, asperidine B, isolated from the soil-derived fungus Aspergillus sclerotiorum PSU-RSPG178, on spasmodic activity. Isolated rat ileum was set up in an organ bath. The contractile responses of asperidine B (0.3 to 30 µM) on potassium chloride and acetylcholine-induced contractions were recorded. To investigate its antispasmodic mechanism, CaCl2, acetylcholine, Nω-nitro-l-arginine methyl ester (l-NAME), nifedipine, methylene blue and tetraethylammonium chloride (TEA) were tested in the absence or in the presence of asperidine B. Cumulative concentrations of asperidine B reduced the ileal contraction by ~37%. The calcium chloride and acetylcholine-induced ileal contraction was suppressed by asperidine B. The effects of asperidine B combined with nifedipine, atropine or TEA were similar to those treated with nifedipine, atropine or TEA, respectively. In contrast, in the presence of l-NAME and methylene blue, the antispasmodic effect of asperidine B was unaltered. These results suggest that the antispasmodic property of asperidine B is probably due to the blockage of the L-type Ca2+ channel and is associated with K+ channels and muscarinic receptor, possibly by affecting non-selective cation channels and/or releasing intracellular calcium.

Low-dose cyclooxygenase-2 (COX-2) inhibitor celecoxib plays a protective role in the rat model of neonatal necrotizing enterocolitis.

This study aims to investigate the effects of the cyclooxygenase-2 (COX-2) inhibitor celecoxib on neonatal necrotizing enterocolitis (NEC) in rats. After treatment with a low dose of celecoxib (0.5, 1, or 1.5 mg/kg), pathological changes in the ileum and the levels of oxidative stress and inflammatory factors in NEC rats were compared. Enzyme-linked immunosorbent assay (ELISA) was employed to detect inflammatory factors, terminal deoxyribonucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling (TUNEL) staining was employed to assess apoptotic epithelial cells in the ileum, and real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting were used to quantify gene and protein expression, respectively. The incidences of NEC rats in the 0.5, 1 and 1.5 mg/kg celecoxib groups were lower than in the model group (100%). Celecoxib improved the histopathology of the ileum in NEC rats. Moreover, low doses of celecoxib relieved oxidative stress and inflammation in NEC rats, as evidenced by decreased tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), total oxidation state (TOS), malondialdehyde (MDA) and oxidative stress index (OSI), as well as increased interleukin-10 (IL-10), total antioxidant status (TAS), superoxide dismutase (SOD) and glutathione peroxidase (GPx). With increasing celecoxib doses (0.5, 1, or 1.5 mg/kg), the amount of apoptotic epithelial cells in the ileum of NEC rats gradually declined and Caspase-3 expression was reduced. The low dose of the COX-2 inhibitor celecoxib ameliorated the histopathologic conditions of the ileum, alleviated oxidative stress and inflammation, and reduced apoptotic epithelial cells in NEC rats, thereby making it a potential therapy for NEC.

Dietary starch is weight reducing when distally digested in the small intestine.

Nowadays, carbohydrate-based foods have a negative consumer connotation and low carb diets have become a popular way to lose weight. Here, we show how digestible starch and flavonoids can be used as a dietary approach to manage food intake and weight gain through elevation of glucagon-like peptide-1 (GLP-1) secretion for gut-brain axis communication. This was achieved by extending the digestion of cooked starch to the distal small intestine using luteolin or quercetin as α-amylase-specific inhibitors with competitive inhibition mechanism. In a mouse model, extended and complete digestion produced a signature blunted glycemic profile that induced elevation of GLP-1 and positive regulation of hypothalamic neuropeptides with significantly reduced food intake and weight gain (p < 0.05). These findings represent a shift in paradigm of dietary carbohydrates from weight increasing to reducing, and have implications for industry and public health related to the design of carbohydrate-based foods/ingredients for managing obesity and diabetes.