Restraint water-immersion stress (RWIS), a compound stress model, has been widely used to induce acute gastric ulceration in rats. A wealth of evidence suggests that the central nucleus of the amygdala (CEA) is a focal region for mediating the biological response to stress. Different stressors induce distinct alterations of neuronal activity in the CEA; however, few studies have reported the characteristics of CEA neuronal activity induced by RWIS. Therefore, we explored this issue using immunohistochemistry and in vivo extracellular single-unit recording. Our results showed that RWIS and restraint stress (RS) differentially changed the c-Fos expression and firing properties of neurons in the medial CEA. In addition, RWIS, but not RS, induced the activation of corticotropin-releasing hormone neurons in the CEA. These findings suggested that specific neuronal activation in the CEA is involved in the formation of RWIS-induced gastric ulcers. This study also provides a possible theoretical explanation for the different gastric dysfunctions induced by different stressors.
Action Potentials ; drug effects ; physiology ; Analysis of Variance ; Animals ; Central Amygdaloid Nucleus ; pathology ; Corticotropin-Releasing Hormone ; metabolism ; Disease Models, Animal ; Gastric Mucosa ; pathology ; Gene Expression Regulation ; physiology ; Neurons ; physiology ; Patch-Clamp Techniques ; Proto-Oncogene Proteins c-fos ; metabolism ; Rats ; Rats, Wistar ; Stress, Physiological ; physiology ; Stress, Psychological ; etiology ; physiopathology

OBJECTIVEVigna subterranea is widely consumed as a traditional staple food in Nigeria and some West African countries. The ethanolic seed extract of V. subterranea (EEVS) was investigated for its gastroprotective effects on aspirin plus pylorus ligation-induced gastric ulcerated rats using an in vivo assay.

METHODSGastric mucosal ulceration was induced experimentally in Groups 2 to 5 using aspirin plus pylorus ligation. Rats in Group 1 were orally pretreated with 3% Tween 80 only as normal control. Groups 2 to 5 were pretreated with 3% Tween 80 (ulcer group), 20 mg/kg of omeprazole (positive group), and 200 and 400 mg/kg of EEVS (experimental groups), respectively, once daily for 21 days before ulcer induction. Parameters including those for gastric secretions, ulcerated areas and gastric wall histology were assessed. Levels of superoxide dismutase (SOD), glutathione peroxidase (GP), and malondialdehyde (MDA) in the gastric tissue homogenate were also determined.

RESULTSPretreatment with EEVS significantly (P < 0.05) reduced the ulcer index, gastric volume and total acidity in rats with aspirin plus pylorus ligation-induced ulcer. The pH and mucus of gastric content increased significantly (P < 0.05) while the levels of SOD and GP were observed to be elevated with a reduced amount of MDA. Significant severe gastric mucosal injury was exhibited in the ulcer group and EEVS or omeprazole offered significant (P < 0.05) protection against mucosal ulceration. Histologically, the gastric submucosal layer showed remarkable decrease in edema and leucocytes infiltration compared with ulcer group.

CONCLUSIONThe study suggests that EEVS offered a protective action against aspirin plus pylorus ligation-induced gastric ulcers in Wistar rats. The protective effect might be mediated via antisecretory, cytoprotective and antioxidative mechanisms.

Animals ; Anti-Ulcer Agents ; pharmacology ; therapeutic use ; Antioxidants ; pharmacology ; therapeutic use ; Aspirin ; Edema ; Gastric Mucosa ; drug effects ; metabolism ; pathology ; Gastrointestinal Agents ; pharmacology ; therapeutic use ; Glutathione Peroxidase ; metabolism ; Hydrogen-Ion Concentration ; Leukocytes ; Male ; Malondialdehyde ; metabolism ; Mucus ; metabolism ; Nuts ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Rats, Wistar ; Severity of Illness Index ; Stomach Ulcer ; chemically induced ; drug therapy ; metabolism ; prevention & control ; Superoxide Dismutase ; metabolism ; Vigna

The epithelial cytokine response, associated with reactive oxygen species (ROS), is important in Helicobacter pylori (H. pylori)-induced inflammation. H. pylori induces the production of ROS, which may be involved in the activation of mitogen-activated protein kinases (MAPK), janus kinase/signal transducers and activators of transcription (Jak/Stat), and oxidant-sensitive transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB), and thus, expression of interleukin-8 (IL-8) in gastric epithelial cells. alpha-lipoic acid, a naturally occurring thiol compound, is a potential antioxidant. It shows beneficial effects in treatment of oxidant-associated diseases including diabetes. The present study is purposed to investigate whether alpha-lipoic acid inhibits expression of inflammatory cytokine IL-8 by suppressing activation of MAPK, Jak/Stat, and NF-kappaB in H. pylori-infected gastric epithelial cells. Gastric epithelial AGS cells were pretreated with or without alpha-lipoic acid for 2 h and infected with H. pylori in a Korean isolate (HP99) at a ratio of 300:1. IL-8 mRNA expression was analyzed by RT-PCR analysis. IL-8 levels in the medium were determined by enzyme-linked immunosorbent assay. NF-kappaB-DNA binding activity was determined by electrophoretic mobility shift assay. Phospho-specific and total forms of MAPK and Jak/Stat were assessed by Western blot analysis. ROS levels were determined using dichlorofluorescein fluorescence. As a result, H. pylori induced increases in ROS levels, mRNA, and protein levels of IL-8, as well as the activation of MAPK [extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase 1/2 (JNK1/2), p38], Jak/Stat (Jak1/2, Stat3), and NF-kappaB in AGS cells, which was inhibited by alpha-lipoic acid. In conclusion, alpha-lipoic acid may be beneficial for prevention and/or treatment of H. pylori infection-associated gastric inflammation.
Enzyme-Linked Immunosorbent Assay ; Epithelial Cells/metabolism ; Gastric Mucosa/*drug effects/metabolism/microbiology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/immunology/*metabolism ; Helicobacter pylori/drug effects/*pathogenicity ; Humans ; Interleukin-8/genetics/*metabolism ; JNK Mitogen-Activated Protein Kinases ; Janus Kinase 1 ; Mitogen-Activated Protein Kinases/*biosynthesis ; NF-kappa B/*metabolism ; RNA, Messenger/isolation & purification/metabolism ; Reactive Oxygen Species/metabolism ; STAT3 Transcription Factor ; Stomach/metabolism/*microbiology ; Thioctic Acid/*pharmacology

OBJECTIVETo study the effects of Weipixiao (胃痞消, WPX) on Wnt pathway-associated proteins in gastric mucosal epithelial cells from rats with gastric precancerous lesions (GPL).

METHODSSprague Dawley rats were randomly divided into control, model, vitacoenzyme (0.2 g·kg(-1)·day(-1)), WPX high-dose (H-WPX, 15 g·kg(-1)·day(-1)), WPX medium-dose (M-WPX, 7.5 g·kg(-1)·day(-1)) and WPX low-dose (L-WPX, 3.75 g·kg(-1)·day(-1)) groups. After successfully establishing the GPL model, the rats were consecutively administered WPX or vitacoenzyme by gastrogavage for 10 weeks. Differential expression of Leucine-rich repeat-containing G-proteincoupled receptor 5 (Lgr5), matrix metalloproteinase-7 (MMP-7), Wnt1, Wnt3a, and β-catenin in gastric mucosal epithelial cells in all groups were immunohistochemically detected, and the images were taken and analyzed semiquantitatively by image pro plus 6.0 software.

RESULTSGastric epithelium in the model group showed significantly higher expression levels of Lgr5, MMP-7, Wnt1, Wnt3a and β-catenin than those of the control group(P<0.01). Interestingly, we also observed Lgr5+ cells, which generally located at the base of the gastric glandular unit, migrated to the luminal side of gastric epithelium with GPL. The expression levels of Lgr5, MMP-7, Wnt1, and β-catenin were all down-regulated in the L-WPX group as compared with those of both model and vitacoenzyme groups (P<0.05). A similar, but nonsignificant down-regulation in expression level of Wnt3a was noted in all WPX groups (P>0.05).

CONCLUSIONOur findings suggested that the therapeutic mechanisms of WPX in treating GPL might be related with its inhibitory effects on the expressions of Lgr5, MMP-7, Wnt1, β-catenin and the aberrant activation of Wnt/β-catenin pathway.

Animals ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Gastric Mucosa ; pathology ; Immunohistochemistry ; Male ; Matrix Metalloproteinase 7 ; metabolism ; Precancerous Conditions ; drug therapy ; pathology ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; metabolism ; Staining and Labeling ; Stomach Neoplasms ; drug therapy ; pathology ; Wnt Proteins ; metabolism ; Wnt Signaling Pathway ; drug effects ; beta Catenin ; metabolism

NADPH oxidase produces a large amount of reactive oxygen species (ROS) in Helicobacter pylori (H. pylori)-induced gastric epithelial cells. Even though ROS mediate apoptotic cell death, direct involvement of NADPH oxidase on H. pylori-induced apoptosis remains unclear. Besides, H. pylori isolates show a high degree of genetic variability. The predominant genotype of H. pylori in Korea has been reported as cagA+, vacA s1b, m2, iceA genotype. Present study aims to investigate whether NADPH oxidase-generated ROS mediate apoptosis in human gastric epithelial AGS cells infected with H. pylori in a Korean isolate. AGS cells were pretreated with or without an NADPH oxidase inhibitor diphenyleneiodonium (DPI) and cultured in the presence of H. pylori at a bacterium/cell ratio of 300:1. Cell viability, hydrogen peroxide level, DNA fragmentation, and protein levels of p53, Bcl-2, and Bax were determined. Results showed that H. pylori inhibited cell viability with the density of H. pylori added to the cells. Inhibition of NADPH oxidase by DPI suppressed H. pylori-induced cell death, increased hydrogen peroxide, DNA fragmentation, and the ratio of Bax/Bcl-2, and p53 induction in AGS cells dose-dependently. The results suggest that targeting NADPH oxidase may prevent the development of gastric inflammation associated with H. pylori infection by suppressing abnormal apoptotic cell death of gastric epithelial cells.
Apoptosis ; Apoptosis Regulatory Proteins/metabolism ; Cell Survival ; Epithelial Cells/metabolism/microbiology ; Gastric Mucosa/metabolism ; Helicobacter Infections/*metabolism/microbiology ; Helicobacter pylori/drug effects/genetics/*isolation & purification ; Humans ; NADPH Oxidase/metabolism ; Onium Compounds/*antagonists & inhibitors/pharmacology ; Oxidative Stress/drug effects ; Reactive Oxygen Species/metabolism ; Republic of Korea ; Stomach/cytology/*metabolism/microbiology

Helicobacter pylori (H. pylori) induces the activation of nuclear factor-kB (NF-kappaB) and cytokine expression in gastric epithelial cells. The Janus kinase/signal transducers and activators of transcription (Jak/Stat) cascade is the inflammatory signaling in various cells. The purpose of the present study is to determine whether H. pylori-induced activation of NF-kappaB and the expression of interleukin-8 (IL-8) are mediated by the activation of Jak1/Stat3 in gastric epithelial (AGS) cells. Thus, gastric epithelial AGS cells were infected with H. pylori in Korean isolates (HP99) at bacterium/cell ratio of 300:1, and the level of IL-8 in the medium was determined by enzyme-linked immonosorbent assay. Phospho-specific and total forms of Jak1/Stat3 and IkappaBalpha were assessed by Western blot analysis, and NF-kappaB activation was determined by electrophoretic mobility shift assay. The results showed that H. pylori induced the activation of Jak1/Stat3 and IL-8 production, which was inhibited by a Jak/Stat3 specific inhibitor AG490 in AGS cells in a dose-dependent manner. H. pylori-induced activation of NF-kappaB, determined by phosphorylation of IkappaBalpha and NF-kappaB-DNA binding activity, were inhibited by AG490. In conclusion, Jak1/Stat3 activation may mediate the activation of NF-kappaB and the expression of IL-8 in H. pylori-infected AGS cells. Inhibition of Jak1/Stat3 may be beneficial for the treatment of H. pylori-induced gastric inflammation, since the activation of NF-kappaB is inhibited and inflammatory cytokine expression is suppressed.
Blotting, Western ; DNA, Bacterial/analysis/genetics ; Epithelial Cells/metabolism ; Gastric Mucosa/drug effects/*immunology/microbiology ; Gene Expression Regulation/drug effects/*immunology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/immunology/*metabolism ; Helicobacter pylori/genetics/pathogenicity/*physiology ; Humans ; Interleukin-8/genetics/*metabolism ; Janus Kinase 1 ; NF-kappa B/biosynthesis/*metabolism ; Phosphorylation ; RNA, Messenger/metabolism ; STAT3 Transcription Factor ; Signal Transduction/genetics

Helicobacter pylori (H. pylori) induces the activation of nuclear factor-kB (NF-kappaB) and cytokine expression in gastric epithelial cells. The Janus kinase/signal transducers and activators of transcription (Jak/Stat) cascade is the inflammatory signaling in various cells. The purpose of the present study is to determine whether H. pylori-induced activation of NF-kappaB and the expression of interleukin-8 (IL-8) are mediated by the activation of Jak1/Stat3 in gastric epithelial (AGS) cells. Thus, gastric epithelial AGS cells were infected with H. pylori in Korean isolates (HP99) at bacterium/cell ratio of 300:1, and the level of IL-8 in the medium was determined by enzyme-linked immonosorbent assay. Phospho-specific and total forms of Jak1/Stat3 and IkappaBalpha were assessed by Western blot analysis, and NF-kappaB activation was determined by electrophoretic mobility shift assay. The results showed that H. pylori induced the activation of Jak1/Stat3 and IL-8 production, which was inhibited by a Jak/Stat3 specific inhibitor AG490 in AGS cells in a dose-dependent manner. H. pylori-induced activation of NF-kappaB, determined by phosphorylation of IkappaBalpha and NF-kappaB-DNA binding activity, were inhibited by AG490. In conclusion, Jak1/Stat3 activation may mediate the activation of NF-kappaB and the expression of IL-8 in H. pylori-infected AGS cells. Inhibition of Jak1/Stat3 may be beneficial for the treatment of H. pylori-induced gastric inflammation, since the activation of NF-kappaB is inhibited and inflammatory cytokine expression is suppressed.
Blotting, Western ; DNA, Bacterial/analysis/genetics ; Epithelial Cells/metabolism ; Gastric Mucosa/drug effects/*immunology/microbiology ; Gene Expression Regulation/drug effects/*immunology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/immunology/*metabolism ; Helicobacter pylori/genetics/pathogenicity/*physiology ; Humans ; Interleukin-8/genetics/*metabolism ; Janus Kinase 1 ; NF-kappa B/biosynthesis/*metabolism ; Phosphorylation ; RNA, Messenger/metabolism ; STAT3 Transcription Factor ; Signal Transduction/genetics

BACKGROUND/AIMS: The aims of this study were to investigate whether a broccoli sprout extract containing sulforaphane (BSES) inhibited the Helicobacter pylori infection density and exerted an antioxidative effect on gastric mucosal damage. METHODS: The enrolled subjects were randomized in a double-blinded manner into three groups. Finally, 33 H. pylori (+) BSES treatment subjects (group A), 28 H. pylori (+) placebo subjects (group B), and 28 H. pylori (-) BSES treatment subjects (group C) were studied. H. pylori infection density was indirectly quantified by a 13C-urea breath test (UBT), and the ammonia concentration in gastric juice aspirates was measured through gastroscopic examination. Malondialdehyde (MDA), an oxidative damage biomarker, and reduced glutathione (GSH), an antioxidant biomarker, were measured in the gastric mucosa by an enzyme-linked immunosorbent assay. RESULTS: BSES treatment did not significantly affect the UBT values or ammonia concentration in group A (p=0.634 and p=0.505, respectively). BSES treatment did significantly reduce mucosal MDA concentrations in group A (p<0.05) and group C (p<0.001), whereas the gastric mucosal GSH concentrations did not differ before and after treatment in any of the groups. CONCLUSIONS: BSES did not inhibit the H. pylori infection density. However, BSES prevented lipid peroxidation in the gastric mucosa and may play a cytoprotective role in H. pylori-induced gastritis.
Adult ; Ammonia/metabolism ; Antioxidants/*pharmacology ; Biomarkers/analysis ; Brassica/*chemistry ; Breath Tests ; Double-Blind Method ; Enzyme-Linked Immunosorbent Assay ; Female ; Gastric Juice/enzymology ; Gastric Mucosa/*drug effects/metabolism ; Glutathione/analysis ; Helicobacter Infections/*drug therapy ; *Helicobacter pylori ; Humans ; Isothiocyanates/*pharmacology ; Lipid Peroxidation/*drug effects ; Male ; Malondialdehyde/analysis ; Middle Aged ; Plant Extracts/chemistry/*pharmacology ; Urea

OBJECTIVETo investigate the effect of Rhizoma Atractylodis extract (ERA) in protecting gastric mucosa and modulating gastrointestinal immune function of a rat model of spleen deficiency syndrome and elucidate the mechanism by which ERA improves spleen deficiency syndrome.

METHODSMale rats were fed with Xiaochengqi decoction and subjected to irregular feeding to induce spleen deficiency syndrome. The established models were randomized into model group, high-, moderate- and low-dose ERA groups, and domperidone group. After corresponding treatment for 30 days, the content of IgA in the intestinal lavage fluid, serum IgG, and the indices of the spleen and thymus were determined. The pathological changes in the gastric mucosa was observed with HE staining, gastric mucosal blood flow was evaluated with laser Doppler rheometry, and the expression of TFF1 in the gastric mucosa and TLR4 expression in the colon tissue were detected with immunohistochemistry.

RESULTSThe rat models of spleen deficiency syndrome showed obvious abnormalities in gastric mucosal morphology, blood flow and immunological indexes. Compared with the model rats, the rats receiving ERA treatment as different doses all showed significant improvements in gastric mucosal morphology, blood flow volume, gastric mucosa trefoil factor 1 (TFF1) expression, intestinal lavage fluid IgA content, serum IgG content, indices of the spleen and thymus, and TLR4 expression in the colon TLR4 (P<0.05 or P<0.01).

CONCLUSIONERA can inhibit gastric mucosal damage, protect and repair the damaged mucosal tissues, and improve the immune function of in rats with spleen deficiency.

Animals ; Atractylodes ; chemistry ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Gastric Mucosa ; drug effects ; pathology ; Immunoglobulin A ; metabolism ; Immunoglobulin G ; blood ; Immunohistochemistry ; Male ; Peptides ; metabolism ; Rats ; Rhizome ; chemistry ; Spleen ; physiopathology ; Trefoil Factor-2

BACKGROUND/AIMS: The prevalence of peptic ulcer disease has not decreased mainly due to an increase in the use of NSAIDs. This study was conducted in order to determine whether a chronic NSAID-induced gastric inflammation model could be established by repeated administration of NSAID. METHODS: Indomethacin (10 mg/kg) was administered once per week for six weeks in 8- and 26-week rats and animals were sacrificed every week after administration. Gross ulcer index, histologic damage index, myeloperoxidase (MPO) activity, and mucus (glucosamine) levels were measured. Small bowel damage was also evaluated. RESULTS: Gross gastric damage index showed a peak level at three weeks and then decreased slowly in the 26-week indomethacin group. Gastric mucosal glucosamine level increased in both the 8-week (p=0.038) and 26-week groups (p=0.007). In addition, gastric mucosal MPO level decreased in the 8-week group (p=0.018) but did not show a decrease in the 26-week group. Small bowel damage began to occur at three weeks during the schedule and eight of 36 rats (22.2%) died due to perforation or peritonitis of the small bowel in the 8- and 26-week indomethacin groups, respectively. CONCLUSIONS: Due to gastric adaptation and small bowel damage, repeated administration of NSAID to experimental animals may not be an adequate method for establishment of the chronic gastric inflammation model.
Animals ; Anti-Inflammatory Agents, Non-Steroidal/*toxicity ; Disease Models, Animal ; Gastric Mucosa/*drug effects/enzymology/pathology ; Glucosamine/metabolism ; Indomethacin/*toxicity ; Intestine, Small/*drug effects/pathology ; Male ; Peroxidase/metabolism ; Rats ; Rats, Sprague-Dawley ; Time Factors