Coffee and caffeine intake reduces risk of ulcerative colitis: a case-control study in Japan.

BACKGROUND AND AIM: Although diet is one of the potential environmental factors affecting ulcerative colitis (UC), evidence is not sufficient to draw definitive conclusions. This Japanese case-control study examined the association between the consumption of coffee, other caffeine-containing beverages and food, and total caffeine and the risk of UC. METHODS: The study involved 384 UC cases and 665 control subjects. Intake of coffee, decaffeinated coffee, black tea, green tea, oolong tea, carbonated soft drinks, and chocolate snacks was measured with a semiquantitative food-frequency questionnaire. Adjustments were made for sex, age, pack-years of smoking, alcohol consumption, history of appendicitis, family history of UC, education level, body mass index, and intake of vitamin C, retinol, and total energy. RESULTS: Higher consumption of coffee and carbonated soft drinks was associated with a reduced risk of UC with a significant dose-response relationship (P for trend for coffee and carbonated soft drinks were <0.0001 and 0.01, respectively), whereas higher consumption of chocolate snacks was significantly associated with an increased risk of UC. No association was observed between consumption of decaffeinated coffee, black tea, green tea, or oolong tea and the risk of UC. Total caffeine intake was inversely associated with the risk of UC; the adjusted odds ratio between extreme quartiles was 0.44 (95% confidence interval: 0.29-0.67; P for trend <0.0001). CONCLUSIONS: We confirmed that intake of coffee and caffeine is also associated with a reduced risk of UC in Japan where people consume relatively low quantities of coffee compared with Western countries.

New and Emerging Treatments for Inflammatory Bowel Disease.

BACKGROUND: The specific etiopathogenesis of inflammatory bowel disease (IBD) is still unknown. Although the conventional anti-inflammatory or immunomodulatory drugs relatively nonspecific to pathogenesis have been quite useful in many cases, elucidating the pathogenesis has gradually facilitated developments of disease-specific therapies for refractory cases in the last 2 decades. SUMMARY: With a greater understanding of the multiple overactive signaling pathways of the gut mucosal immune response and enhanced leukocyte trafficking, several biological agents or small molecule drugs following the first novel biologic, anti-tumor necrosis factor α (anti-TNFα), have been developed against several modes of action including adhesion molecules, sphingosine-1-phospate receptors, cytokines (IL-12/23, TL1A, and IL-36), Janus kinase (JAK), and phosphodiesterase. Although preceding biological agents have dramatically changed the IBD treatment strategy, many patients still require alternative therapies due to failure or side effects. Newer treatments are now expected to be provided for better efficacy with an improved adverse event profile. In addition, translational studies have highlighted the new therapeutic concepts' potential, including modulation of host-microbiome interactions, stem therapy for perianal fistula, regulation of fibrosis, regulation of the gut-brain axis, and control of previously less targeted immune cells (B cells and innate lymphoid cells). This paper comprehensively reviewed not only the latest already or shortly available therapies but also emerging promising treatments that will be hopefully established in the future for IBD. KEY MESSAGES: Many kinds of new treatments are available, and promising treatments with new perspectives are expected to emerge for refractory IBD in the future.

Beneficial effect of an omega-6 PUFA-rich diet in non-steroidal anti-inflammatory drug-induced mucosal damage in the murine small intestine.

AIM: To investigate the effect of a fat rich diet on non-steroidal anti-inflammatory drug (NSAID)-induced mucosal damage in the murine small intestine. METHODS: C57BL6 mice were fed 4 types of diets with or without indomethacin. One group was fed standard laboratory chow. The other groups were fed a fat diet consisting of 8% w/w fat, beef tallow (rich in SFA), fish oil, (rich in omega-3 PUFA), or safflower oil (rich in omega-6 PUFA). Indomethacin (3 mg/kg) was injected intraperitoneally from day 8 to day 10. On day 11, intestines and adhesions to submucosal microvessels were examined. RESULTS: In the indomethacin-treated groups, mucosal damage was exacerbated by diets containing beef tallow and fish oil, and was accompanied by leukocyte infiltration (P < 0.05). The mucosal damage induced by indomethacin was significantly lower in mice fed the safflower oil diet than in mice fed the beef tallow or fish oil diet (P < 0.05). Indomethacin increased monocyte and platelet migration to the intestinal mucosa, whereas safflower oil significantly decreased monocyte and platelet recruitment (P < 0.05). CONCLUSION: A diet rich in SFA and omega-3 PUFA exacerbated NSAID-induced small intestinal damage via increased leukocyte infiltration. Importantly, a diet rich in omega-6-PUFA did not aggravate inflammation as monocyte migration was blocked.

Phlebosclerotic colitis that was difficult to distinguish from collagenous colitis.

Phlebosclerotic colitis is a rare and recently known disease entity and its etiology is still to be elucidated. Some phlebosclerotic colitis cases are difficult to distinguish from collagenous colitis because of the similarity of pathological findings. In all Japanese case reports of phlebosclerotic colitis in which an association with the use of Chinese herbal medicine is suspected, sansisi (gardenia fruit) was included, suggesting pathogenesis of this disease. We report a case of phlebosclerotic colitis that wasdifficult to be distinguished from collagenous colitis, and an association with the use of Chinese herbal medicine was suspected as the cause of the disease.

Effect of dietary fat on intestinal inflammatory diseases.

Dietary fat has multiple roles on human health, and some dietary fat is used to treat organic diseases because of its anti-inflammatory effect. It is commonly accepted that omega-3 polyunsaturated fatty acid (PUFA) is beneficial on ischemic heart disease or rheumatic arthritis. On the contrary, effect of omega-3-PUFA on Crohn's disease remained controversial. That effect of omega-3 PUFA differs according to the location of inflamed intestine was hypothesized. To elucidate this hypothesis, to investigate the role of dietary fat on disease activity in different kind of murine models of intestinal inflammatory diseases was planned. The effect of omega-3 PUFA on small intestinal Crohn's disease model and large intestinal Crohn's disease model of mice. Chronic colitis model C57BL/6 mice received two cycles of dextran sodium sulfate solution treatment to induce chronic colitis. Feeding of omega-3 fat-rich diets exacerbated colitis with decrease in adiponectin expression. Chronic small intestinal inflammation model: SAMP1/Yit mice showed remarkable inflammation of the terminal ileum spontaneously. Feeding of omega-3 fat-rich diets for 16 weeks significantly ameliorated the inflammation of the terminal ileum. Enhanced infiltration of leukocytes and expression of mucosal addressin cell adhesion molecule-1 in intestinal mucosa was significantly decreased by omega-3 fat-rich diets treatment. Omega-3 PUFA has dual role, pro-/anti-inflammatory, on intestinal inflammatory diseases. The role of omega-3 fat and the potential for immunonutrition in inflammatory conditions of the gastrointestinal tract will be discussed.

Dietary lipids and sweeteners regulate glucagon-like peptide-2 secretion.

Glucagon-like peptide-2 (GLP-2) is a potent intestinal growth factor derived from enteroendocrine L cells. Although food intake is known to increase GLP-2 secretion, its regulatory mechanisms are largely unknown as a result of its very short half-life in venules. The aims of this study were to compare the effects of luminal nutrients on the stimulation of GLP-2 secretion in vivo using lymph samples and to clarify the involvement of the sweet taste receptor in this process in vitro. Lymph samples were collected from the thoracic duct after bolus administration of dietary lipids or sweetening agents into the duodenum of rats. Human enteroendocrine NCI-H716 cells were also used to compare the effects of various nutrients on GLP-2 secretion. GLP-2 concentrations were measured by ELISA in vivo and in vitro. GLP-2 secretion was enhanced by polyunsaturated fatty acid- and monounsaturated fatty acid-rich dietary oils, dietary carbohydrates, and some kinds of sweeteners in rats; this effect was reproduced in NCI-H716 cells using α-linolenic acid (αLA), glucose, and sweeteners. GLP-2 secretion induced by sweetening agents was inhibited by lactisole, a sweetness-antagonizing inhibitor of T1R3. In contrast, lactisole was unable to inhibit GLP-2 secretion induced by αLA alone. Our results suggested that fatty acid- and sweetener-induced GLP-2 secretion may be mediated by two different pathways, with the sweet taste receptor involved in the regulation of the latter.

Lemon grass (Cymbopogon citratus) ameliorates murine spontaneous ileitis by decreasing lymphocyte recruitment to the inflamed intestine.

OBJECTIVE: Aberrant leukocyte migration has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Lemon grass is a natural herb that contains citral, which suppresses lymphocyte expression of gut homing molecules by inhibiting retinoic acid formation. We therefore hypothesized that lemon grass intake could ameliorate excess migration of leukocytes to the inflamed intestine in chronic ileitis. METHODS: Migration of fluorescence-labeled T cells to microvessels in the ileal mucosa of SAMP1/Yit mice was monitored using intravital microscopy. In some mice, lemon grass solution was administered for two weeks. For evaluation of the effects on chronic ileitis, mice were treated with lemon grass for 26 weeks. RESULTS: Surface expression of beta7 and CCR9 on T lymphocytes was stronger in SAMP1/Yit mice than in AKR/J mice. Lemon grass treatment attenuated the surface expression of beta7-integrin and CCR9. The number of adherent lymphocytes to microvessels in chronic inflamed ileum was significantly few when lymphocytes were isolated from lemon grass treated mice. Long-term lemon grass treatment improved ileitis in SAMP1/Yit mice, which was assessed by body weight, histological changes and the infiltration of beta7-positive cells. CONCLUSION: Lemon grass ameliorated ileitis through decreasing lymphocyte migration by inhibiting beta7-expression, suggesting its therapeutic usefulness for IBD.

An antioxidant resveratrol significantly enhanced replication of hepatitis C virus.

AIM: To elucidate the effect of antioxidants, resveratrol (RVT) and astaxanthin (AXN), on hepatitis C virus (HCV) replication. METHODS: We investigated the effect of recent popular antioxidant supplements on replication of the HCV replicon system OR6. RVT is a strong antioxidant and a kind of polyphenol that inhibits replication of various viruses. AXN is also a strong antioxidant. The replication of HCV RNA was assessed by the luciferase reporter assay. An additive effect of antioxidants on antiviral effects of interferon (IFN) and ribavirin (RBV) was investigated. RESULTS: This is the first report to investigate the effect of RVT and AXN on HCV replication. In contrast to other reported viruses, RVT significantly enhanced HCV RNA replication. Vitamin E also enhanced HCV RNA replication as reported previously, although AXN did not affect replication. IFN and RBV significantly reduced HCV RNA replication, but these effects were dose-dependently hampered and attenuated by the addition of RVT. AXN did not affect antiviral effects of IFN or RBV. CONCLUSION: These results suggested that RVT is not suitable as an antioxidant therapy for chronic hepatitis C.

Omega-3 fatty acids exacerbate DSS-induced colitis through decreased adiponectin in colonic subepithelial myofibroblasts.

BACKGROUND: Although the immunoregulatory effects of omega-3 fatty acid and adiponectin have been postulated, their role in intestinal inflammation is controversial. The aim of this study was to determine whether dietary fat intake influences activity of colonic inflammation through modulating this system. METHODS: C57BL/6 mice received dextran sulfate sodium for induction of colitis. Mice were fed a control diet, omega-3 fat-rich diet, omega-6 fat-rich diet, or saturated fat-rich diet. Some mice were administered a peroxisome proliferator activated receptor-gamma; agonist, pioglitazone. Messenger RNA expression of adiponectin and its receptors were analyzed. Adiponectin expression in colonic mucosa of ulcerative colitis patients was also analyzed. RESULTS: The receptors for adiponectin were found to be ubiquitously expressed in epithelial cells, intraepithelial lymphocytes, lamina proprial mononuclear cells, and subepithelial myofibroblasts from colonic tissue, but adiponectin was only expressed in myofibroblasts. Induction of colitis significantly decreased the expression of adiponectin in colonic mucosa. The omega-3 fat diet group, but not the other fat diet groups, showed exacerbated colitis with a further decrease of adiponectin expression. Pioglitazone treatment ameliorated the level of decrease in adiponectin expression and improved colonic inflammation induced by the omega-3 fat-rich diet. In patients with ulcerative colitis, the expression level of adiponectin in colonic mucosa was also decreased compared with that in control mucosa. CONCLUSIONS: Adiponectin was found to be expressed in myofibroblasts. Adiponectin expression was significantly suppressed by induction of colitis, and aggravation of colitis after exposure to omega-3 fat may be due to a further decrease in the expression level of adiponectin.

Butter feeding enhances TNF-alpha production from macrophages and lymphocyte adherence in murine small intestinal microvessels.

BACKGROUND AND AIM: Dietary fat is known to modulate immune functions. Intake of an animal fat-rich diet has been linked to increased risk of inflammation; however, little is known about how animal fat ingestion directly affects intestinal immune function. The objective of this study was to assess the effect of butter feeding on lymphocyte migration in intestinal mucosa and the changes in adhesion molecules and cytokines involved in this effect. METHODS: T-lymphocytes isolated from the spleen were fluorescence-labeled and injected into recipient mice. Butter was administered into the duodenum, and villus microvessels of the small intestinal mucosa were observed under an intravital microscope. mRNA expression of adhesion molecules and cytokines in the intestinal mucosa were determined by quantitative PCR. The effect of butter feeding on tumor necrosis factor (TNF)-alpha mRNA expression of intestinal macrophages was also determined. RESULTS: Intraluminal butter administration significantly increased lymphocyte adherence to intestinal microvessels accompanied by increases in expression levels of adhesion molecules ICAM-1, MAdCAM-1 and VCAM-1. This accumulation was significantly attenuated by anti-MAdCAM-1 and anti-ICAM-1 antibodies. Butter administration significantly increased TNF-alpha in the lamina proprial macrophages but not interleukin-6. Anti-TNF-alpha treatment attenuated the enhanced expression of adhesion molecules induced by butter administration. CONCLUSION: T-lymphocyte adherence to microvessels of the small intestinal mucosa was significantly enhanced after butter ingestion. This enhancement is due to increase in expression levels of adhesion molecules of the intestinal mucosa, which is mediated by TNF-alpha from macrophages in the intestinal lamina propria.

Combination therapy with tumor-lysate pulsed dendritic cells and antiangiogenic drug TNP-470 for mouse pancreatic cancer.

Most cases of pancreatic cancer are inoperable when diagnosed. Since immunotherapy and antiangiogenic therapy have been reported to be promising for pancreatic cancer, we examined whether the combination of immunotherapy with dendritic cells (DCs) and the antiangiogenic drug TNP-470 induces tumor regression. Syngeneic mouse pancreatic adenocarcinoma cells were orthotopically inoculated into C57/BL6 mice. DCs with or without tumor lysate (TL) were administered i.p. at 4 and 5 weeks. TNP-470 was injected s.c. into tumor-bearing mice every other day from 4 weeks to 6 weeks. We compared anticancer effects in 6 groups: NT (no treatment), DC/TL- (DCs without TL), DC/TL+ (DCs pulsed with TL), TNP (TNP-470 alone), DC/TL-TNP (DC/TL- plus TNP-470) and DC/TL+TNP (DC/TL+ plus TNP-470). We measured tumor volume, mean vascular density (MVD) and vessel diameter by FITC-dextran using an intravital microscope; degrees of proliferation and apoptosis of cancer cells by PCNA and TUNEL; infiltrating lymphocytes and expression levels of VEGF and MMP-9 by immunohistochemistry and immunoblotting. Tumor volume and MVD were significantly suppressed in the treatment groups with prolonged survival rate, especially in the DC/TL+TNP group. There were no significant differences in apoptosis among the 6 groups except DC/TL+. The number of infiltrating CD4+ cells in the DC/TL+ group was higher than that in the NT group. VEGF expression was significantly suppressed in the treatment groups containing TNP-470, and MMP-9 was also suppressed in the groups containing DC/TL+. Our data suggested that TL-pulsed DCs combined with TNP-470 induced regression of mouse pancreatic cancer, possibly through induction of immune responses and suppression of angiogenesis.