W1820 Green Tea Polyphenols Against Colitis in Mouse Models

AGA Abstracts

submucosal layer, and the number of infiltrating β7 integrin positive cells. Conclusion Lemon grass, widely used natural herb, significantly suppressed the increased T lymphocyte migration in the inflamed mucosa induced. Lemon grass also ameliorated colitis possibly through decreasing T cell migration by inhibiting β7 expression, suggesting its therapeutic usefulness for IBD.

and contrasted them with those observed in preterm infants (85-92 % gestation, 33-34 weeks gestation) in the literature. Methods: Eight piglets (Danish Landrace, Yorkshire and Duroc cross), born by caesarian section at 106 days (115 days full gestation) were reared in heated, humidified, and oxygen supplemented incubators. They received total parenteral nutrition (TPN) with variable trophic feeds on days 1-2 and full enteral milk feeds on days 3-4. Manometric recordings in the esophagus were acquired for 7 min on days 2 and 3-4 immediately after the piglets were orally fed, using a water-perfusion 3-port catheter system (2.4mm OD). EM outcomes included: % occurrence of peristaltic and non-peristaltic (i.e., synchronous, incomplete, and retrograde) pressure events and velocity of the peristaltic events. Results: At both time periods, occurrence of peristaltic (30 and 49%) and incomplete (58 and 47%) events predominated over those that were synchronous (5 and 3%) and retrograde (1%) [P<0.001]. Occurrence of peristalsis (30%) was significantly lower than that of non-peristalsis (70%; P=0.014) on day 2, but not on day 3-4 (49% vs 51%, respectively). Overall peristaltic velocity averaged 1.6 ± 0.2 cm/s and did not change over time. Conclusions: Preterm pigs and infants show similar developmental esophageal peristaltic and non-peristaltic profiles (Omari et al. Gastroenterology 1995;109:1757) and peristaltic velocity (Jadcherla & Shaker. Am J Med 2001;111:64). We propose that the preterm piglet is a useful and valid model of human prematurity for the study of esophageal motility during transition from TPN to enteral and oral feeds.

W1820 Green Tea Polyphenols Against Colitis in Mouse Models Helieh S. Oz, Jeffrey L. Ebersole, Willem J. de Villiers About forty% of IBD patients use some kind of complementary and alternative medicine. However the safety and efficacy of these compounds and interaction with other drugs are not fully understood, and therefore, the consequences can be life threatening. Green tea polyphenols (GrTP) are antioxidants and we have previously shown that they inhibit activation of nuclear factor-kB In Vitro and inflammation in an interleukin-2 deficient mouse model of IBD. In this study we examined efficacy GrTP and -(-)-epigallocatechin-3-gallate (EGCG) against inflammatory responses in In Vitro as well as in IL-10 deficient mice that spontaneously develop enterocolitis (resembles Crohn's disease) and DSS-induced ulcerative colitis models in a dose dependent manner. The IL10 deficient mice were transferred from transgenic to conventional facility and exposed to normal flora to activate the inflammation. IL-10 deficient mice developed enterocolitis manifested with histological lesions and rectal prolapse compared to none in the control IL-10+/+ WT mice. IL-10 deficient mice had significantly higher serum amyloid A (100 times) and interleukin 1beta (200 times) compared to IL-10+/+ WT mice. To study the efficacy of GTP against enterocolitis, IL-10+/+ and IL10-/- were divided into groups and received medicated food pellets contained different doses of GrTP or shame control for a period of 10 consecutive weeks. At the end of experiment, blood and tissue samples were collected to measure cytokines. DSS animals were treated with different doses of GrTP or EGCG and compared to sulfasalazine treated animals. Results, animals tolerated GrTP and EGCG in their daily diets during study period with no significant side effects. GrTP significantly decreased histological scores. The inflammatory cytokines including TNF-alfa and IL-6 were significantly improved with GrTP and sulfasalazine therapy. In conclusion, sulfasalazine, GTP, EGCG respectively attenuated severity of disease compared to untreated colitis in the colitis models. This study was supported by NIH-NCCAM grant AT1490 (H. Oz).

W1818 Chromium Supplementation Decreases Insulin Resistance and Trunk Fat Ellie Aghdassi, Irving E. Salit, Saira Mohammed, Bianca M. Arendt, Johane P. Allard Background: HAART-associated effects on glucose control, insulin resistance (IR), lipid metabolism, and body fat redistribution (BFR) including central obesity may increase the risk of cardiovascular disease in patients living with HIV (PLWH). Chromium (Cr) is an essential micronutrient; Cr deficiency has been reported to cause IR, hyperglycemia and hyperlipidemia. The purpose of this study was to investigate the effect of chromium supplementation on metabolic abnormalities and IR in PLWH. Method: This was a randomized, double blind, placebo-controlled trial in 59 HIV-positive subjects with evidence of BFR, elevated lipids or glucose and who were found to have IR based on the calculation of homeostatic model of assessment (HOMA= (fasting blood glucose x fasting insulin) / 22.5). For inclusion, the HOMA had to be> 2.5. Subjects were randomized to receive either 400 ug of Cr-nicotinate (Cr) or placebo (P) for a period of 16 weeks. Fasting blood insulin, glucose and lipid profile were monitored. Lipodystrophy score (LS) was calculated at baseline and body composition was monitored by DEXA scan. Compliance was assessed by pill counts and was 98.5% in Cr and 89.7% in the P group. Results are reported as Mean(SEM). Analysis was done using paired t-tests to compare pre and post supplementation results. Results :Fifty subjects (47 male, 3 female), 25 in each group completed the study. Subjects in the Cr group were significantly younger (Cr:46.9 (1.4); P: 51.0 (1.4); p=0.048). Otherwise both groups were similar with respect to gender distribution, BMI (Cr: 26.6 (0.8); P: 26.1(0.7) kg/m2), CD4 count (Cr: 489 (55); P: 470 (48)) and LS (Cr: 8.2 (1.4); P: 8.3 (1.5)).Viral load was undetectable in 72.4% of Cr and 63.0% of P groups. Body weight and medication profile remained stable throughout the study for both groups. Cr supplementation resulted in a significant (P<0.05) decrease in: blood insulin (pre: 142(18); post:101(10) pmol/l), plasma triglycerides (pre: 2.9(0.4); post: 2.4(0.3) mmol/l), HOMA (pre: 6.0(0.9); post: 4.6(0.7)) and trunk fat mass (pre:9.9(0.9); post: 9.4(1.0) kg). Blood glucose remained unchanged. These parameters did not change in the placebo group: blood insulin (pre: 126(20); post:117 (17) pmol/l), blood triglycerides (pre: 2.3(0.2); post: 2.4 (0.3) mmol/l), HOMA (pre: 5.8 (1.1); post: 6.5 (2.0)) and trunk fat mass (pre:8.9 (0.7); post: 8.8 (0.8) kg). Conclusion: Cr supplementation may be of benefit in antiretroviral-treated patients who have metabolic abnormalities and abdominal obesity.

W1821 Protein Kinase D Mediates Nf-κB Activation Induced By Cholecystokinin and Cholinergic Signaling in Pancreatic Acinar Cells Jingzhen Yuan, Aurelia Lugea, Ling Zheng, Ilya Gukovsky, Mouad Edderkaoui, Stephen J. Pandol BACKGROUND: The transcription factor NF-κB plays a critical role in inflammatory and cell death responses during acute pancreatitis. Thus, elucidating the signaling mechanisms underlying the NF-κB activation is important for understanding of the pathophysiology of pancreatitis. Previous studies in our laboratory demonstrated that protein kinase C (PKC) isoforms PKCδ and ε are key regulators of NF-κB activation induced by cholecystokinin-8 (CCK). However, the downstream signaling targets of these PKCs within the NF-κB pathway in pancreatitis remain poorly understood. Protein kinase D (PKD), a serine/threonine protein kinase with structural, enzymological and regulatory properties different from the PKC family members, has emerged as a major target in the signal transduction pathways initiated by diacylglycerol and PKC in a variety of cell types. Therefore, we investigated whether PKD is activated in pancreatic acinar cells by the two major secretagogues, CCK and cholinergic receptor agonist carbachol (CCh); which PKCs are involved in PKD activation; and whether PKD regulates NF-κB activation in pancreatic acinar cells. RESULTS: Both CCK and CCh dose-dependently induced a rapid (within minus) and striking activation of PKD in rat pancreatic acinar cells, as measured by In Vitro kinase assay and phosphorylation at the activation loop (Ser744/748) and autophosphorylation site (Ser916). The activation and phosphorylation of PKD closely correlated with NF-κB activity stimulated by CCK or CCh, as measured by NF-κB-DNA binding using EMSA and TransAM p65 NF-κB ELISA kit. PKD activation in response to either of the two agonists in pancreatic acinar cells is through PKCδ- and PKCε-dependent pathways. Pre-incubation of acinar cells with isoform-specific and cell permeable inhibitory peptides for PKCδ or ε markedly decreased (~50%) both PKD and NF-κB activation. Further, PKD activity induced by CCK or CCh was reduced in pancreatic acinar cells from mice genetically deficient in PKCδ or ε. To determine the role of PKD in NF-κB activation, rat pancreatic acinar AR42J cells were transfected with small interfering RNAs targeting distinct PKD sequences. The results showed that PKD knockdown with siRNA dramatically reduced CCK- or CCh-stimulated NF-κB activity in AR42J cells. CONCLUSION: Our results identify PKD as a novel early convergent point of PKCδ and ε in the signaling pathways trigged through CCK or cholinergic receptor and demonstrate, for the first time, that PKD mediates NF-κB activation induced by CCK and cholinergic stimulation in pancreatic acinar cells.

W1819 Lemon Grass (Cymbopogon Citratus) Ameliorates Murine Spontaneous Ileitis By Decreasing T Lymphocytes Migration to Inflamed Intestinal Microvessels Chikako Watanabe, Ryota Hokari, Mitsuyasu Nakamura, Shunsuke Komoto, Yoshikiyo Okada, Chie Kurihara, Michiko Miyagi, Hirokazu Yokoyama, Toshifumi Hibi, Soichiro Miura Background & Aim Aberrant leukocyte migration has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Recently vitamin A (retinol) metabolite, retinoic acid (RA), is reported to play a key role on T cell migration to the gut by enhancing the expression of β7 integrin on T cells. Lemon grass (Cymbopogon citratus) is widely used in Thai and Vietnamese cooking. This grass is rich in a substance called citral, which decreases RA by inhibiting metabolism of retinol to RA. Thus we hypothesized that this natural herb intake could attenuate excess migration of leukocytes recruitment to the inflamed intestinal mucosa by decreasing β7 integrin expression. We investigated whether lemon grass drinking could improve spontaneously developed ileitis in SAMP1/Yit mice. Method Concentration of RA was mesured by HPLC method. We chose SAMP1/Yit mice as a chronic ileitis model and AKR/J mice as control. Lemon grass was boiled and added to the drinking water. Some mice received this herb tea for 2 weeks before isolation of T cells. T cells were isolated from the spleen. Expression of β7-integrin on T lymphocytes was analyzed by FACS. CFSE labeled T cells were administered via the jugular vein of recipient mouse. Adhesion of lymphocytes to microvessels in the intestinal mucosa was monitored using intravital microscopy. To evaluate the effects of lemon grass drinking on the chronic ileitis histologicaly, some mice were treated with long-term lemon grass drinking. We evaluated as follows, body weight, weight of ileum, submucosal thickening, MAdCAM-1 expression and the number of β7 integrin positive cells in the intestinal mucosa. Result Conversion of retinal into retinoic acid by addition of the protein extract from the mescentric lymph node was comfirmed by HPLC method. The expression of β7-integrin was stronger in SAMP1/Yit mice compared with AKR/J mice. Lemon grass drinking attenuated the expression of this β7 integrin both in AKR/J and in SAMP1/Yit mice. The increased number of lymphocytes adhered to chronic inflamed ileum. Fewer lymphocytes from lemon grass drinking mice adhered than those from non-drinking mice. In SAMP1/Yit chronic inflamed model, ‘lemon grass treatment' improved ileitis histologically. It ameliorated the body weight loss, the thickness of intestinal

AGA Abstracts

W1822 Gdnf-Mediated Increase in β-Cell Mass and Resistance to STZ-Induced Hyperglycemia Is Associated with Increased Cell Proliferation, and Pdx1 and Sox9 Expression Simon Mwangi, Shreya M. Raja, Kavya Sebastian, Shanthi Srinivasan Background: We have previously shown that transgenic mice engineered to over-express glial cell line-derived neurotrophic factor (GDNF), a growth factor for enteric neurons, in glia have a larger β-cell mass, improved glucose tolerance, and increased resistance to streptozotocin (STZ)-induced hyperglycemia than their wild type (WT) littermates. However, the mechanisms involved are not known. Pancreatic and duodenal homeobox gene 1 (Pdx1), Sox9 and Hairy-and Enhancer-of-split 1 (Hes1) mark a pool of multi-potential progenitor cells in the developing pancreas, while later in life Pdx1 and follicular growth factor receptor

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