Zinc (Zn) has an existence within large quantities in the human brain, while accumulating within synaptic vesicle. There is growing evidence that Zn metabolic equilibrium breaking participates into different diseases (e.g., vascular dementia, carcinoma, Alzheimer's disease). Carnosine refers to an endogenic dipeptide abundant in skeletal muscle and brains and exerts a variety of positive influences (e.g., carcinoma resistance, crosslinking resistance, metal chelation and oxidation limitation). A complex of Zn and carnosine, called Zinc-L-carnosine (ZnC), has been extensively employed within Zn supplement therapeutic method and the treating approach for ulcers. ZnC has been shown to play a variety of roles in the body, including inhibiting intracellular reactive oxygen species(ROS) and free radical levels, inhibiting inflammation, supplementing zinc enzymes and promoting wound healing and mucosal cell repair. The present study conducting a reviewing process for the advances of ZnC in tumor adjuvant therapy.

Gastric ulcer is one of the most common chronic gastrointestinal diseases characterized by a significant defect in the mucosal barrier. Helicobacter pylori (H. pylori) infection and the frequent long-term use of non-steroidal anti-inflammatory drugs are major factors involved in gastric ulcer development. Acid inhibitors and antibiotics are commonly used to treat gastric ulcer. However, in the last few decades, the accumulating evidence for resistance to antibiotics and the side effects of antibiotics and acid inhibitors have drawn attention to the possible use of probiotics in the prevention and treatment of gastric ulcer. Probiotics are live microorganisms that when administered in adequate amounts confer health benefits on the host. Currently, the available experimental and clinical studies indicate that probiotics are promising for future applications in the management of gastric ulcers. This review aims to provide an overview of the general health benefits of probiotics on various systemic and gastrointestinal disorders with a special focus on gastric ulcer and the involved cellular and molecular mechanisms: i) Protection of gastric mucosal barrier; ii) upregulation of prostaglandins, mucus, growth factors and anti-inflammatory cytokines; iii) increased cell proliferation to apoptosis ratio; and iv) induction of angiogenesis. Finally, some of the available data on the possible use of probiotics in H. pylori eradication are discussed.

Bacterial infections, including surgical site infections (SSI), are a common and serious complication of diabetes. Staphylococcus aureus, which is eliminated mainly by neutrophils, is a major cause of SSI in diabetic patients. However, the precise mechanisms by which diabetes predisposes to staphylococcal infection are not fully elucidated. The effect of insulin on this infection is also not well understood. We therefore investigated the effect of insulin treatment on SSI and neutrophil function in diabetic mice. S. aureus was inoculated into the abdominal muscle in diabetic db/db and high-fat-diet (HFD)-fed mice with or without insulin treatment. Although the diabetic db/db mice developed SSI, insulin treatment ameliorated the infection. db/db mice had neutrophil dysfunction, such as decreased phagocytosis, superoxide production, and killing activity of S. aureus; however, insulin treatment restored these functions. Ex vivo treatment (coincubation) of neutrophils with insulin and euglycemic control by phlorizin suggest that insulin may directly activate neutrophil phagocytic and bactericidal activity independently of its euglycemic effect. However, insulin may indirectly restore superoxide production by neutrophils through its euglycemic effect. HFD-fed mice with mild hyperglycemia also developed more severe SSI by S. aureus than control mice and had impaired neutrophil phagocytic and bactericidal activity, which was improved by insulin treatment. Unlike db/db mice, in HFD mice, superoxide production was increased in neutrophils and subsequently suppressed by insulin treatment. Glycemic control by insulin also normalized the neutrophil superoxide-producing capability in HFD mice. Thus, insulin may restore neutrophil phagocytosis and bactericidal activity, thereby ameliorating SSI.

The protective effect of a probiotic mixture of 13 different bacteria and α-tocopherol on 98% ethanol-induced gastric mucosal injury was evaluated. Levels of gastric mucosal pro- and anti-inflammatory cytokines, malondialdehyde, and secretory immunglobulin A were measured. Rats were allocated into four groups: control, ethanol, probiotic, and α-tocopherol. The control and ethanol groups received skim milk for 14 days. Probiotic and α-tocopherol groups were administered probiotic mixture suspended in skim milk and 100 mg/kg α-tocopherol, respectively, by daily gavage for 14 days. On Day 15, gastric lesions were induced by administration of ethanol 98% (1 mL) to all rats except those in the control group. Probiotic, but not α-tocopherol, seemed to inhibit ethanol-induced gastric mucosal tumor necrosis factor-α, interferon-γ, and interleukin-2 production (P > .05). Ethanol caused the elevation of mucosal interleukin-4 level (compared to the control, P < .05). Probiotic pretreatment significantly suppressed the ethanol-induced increase of gastric mucosal interleukin-4 levels. Pretreatment with either probiotic or α-tocopherol inhibited the ethanol-induced increase of mucosal malondialdehyde concentration (P < .01 and P < .05, respectively). Probiotic pretreatment enhanced the gastric mucosal secretory immunoglobulin A concentration (P < .001). In conclusion, probiotic mixture and α-tocopherol reduced ethanol-induced gastric mucosal lipid peroxidation, suggesting that they may be beneficial for gastric lesions induced by lower ethanol concentration.

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin induce gastric mucosal lesions in part by the activation of inflammatory cells and the production of proinflammatory cytokines. The activation of adenosine A(2A) receptors inhibits inflammation by increasing cyclic AMP in leukocytes and reducing both the production of various proinflammatory cytokines and neutrophil chemotaxis. The aim of present study was to determine whether administration of an orally active adenosine A(2A) receptor agonist (4-[3-[6-amino-9-(5-cyclopropylcarbamoyl-3,4-dihydroxy-tetrahydro-furan-2-yl)-9H-purin-2-yl]-prop-2-ynyl]-piperidine-1-carboxylic acid methyl ester; ATL-313) ameliorated indomethacin-induced gastric mucosal lesions in rats.

Gastric lesions were produced by oral gavage of indomethacin (30 mg/kg). ATL-313 (1-10 microg/kg) was given orally just before the indomethacin administration.

The ulcer index induced by indomethacin was significantly (>50%) reduced by pretreatment with ATL-313 and this effect was blocked completely by the addition of equimolar ZM241385, a selective A(2A) receptor antagonist. The gastric content of myeloperoxidase (MPO) and proinflammatory cytokines was significantly reduced by 10 microg/kg ATL-313, but gastric mucosal prostaglandin 2 (PGE2) was not affected.

We conclude that ATL-313 does not inhibit the mucosal damaging effect of indomethacin, but it does block secondary injury due to stomach inflammation. A(2A) agonists may represent a class of new therapeutic drugs for NSAID-induced gastric ulcers.

Cilostazol, a selective type III phosphodiesterase inhibitor, is widely used for treatment of ischemic symptoms of peripheral vascular disease. Recent studies have reported that the mechanism of cilostazol is related to suppression of pro-inflammatory cytokine production and improvement of local microcirculation disturbances. The activation of inflammatory cells and pro-inflammatory cytokine production play critical roles in the pathogenesis of aspirin-induced gastric irritation. The aim of the present study was to determine whether cilostazol can ameliorate aspirin-induced gastric mucosal lesions in rats, reduce neutrophil accumulation, and reduce the production of pro-inflammatory cytokines. Gastric lesions were produced by oral gavage of aspirin (200 mg/kg) and HCl (0.15 N, 8.0 ml/kg). Cilostazol (1-10 mg/kg, IP) was injected 30 min before aspirin administration. Also, we measured the gastric mucosal concentrations of myeloperoxidase and interleukin-1 beta, tumor necrosis factor-alpha, and cytokine-induced neutrophil chemoattractants-1, as an index of neutrophil accumulation, and the pro-inflammatory cytokines. Cilostazol ameliorated the gastric mucosal lesions induced by aspirin administration (P<0.01). The gastric contents of myeloperoxidase and pro-inflammatory cytokines were all increased after aspirin administration and significantly reduced by cilostazol treatment. In this study, we demonstrated that a selective type III phosphodiesterase inhibitor, cilostazol, reduced aspirin-induced gastric inflammation and damage via suppression of the production of proinflammatory cytokines. Cilostazol may be useful for preventing gastric mucosal lesions induced by aspirin.

The pleural cavity is normally in a state of negative pressure and low oxygen tension. It is exposed to the atmosphere during thoracic surgery. However, no reports of pathophysiological investigation of the effects of pleural oxygen exposure involved in thoracotomy are available. In this study, the effects of pleural oxygen exposure on systemic and pleural inflammation were investigated. Male Wistar rats (9 weeks old) were placed on mechanical ventilation and underwent thoracotomy with lipopolysaccharide (LPS) administration, which simulates latent inflammatory condition. The pleural cavity was exposed to nitrogen (N(2) thoracotomy group), air (20% oxygen, air thoracotomy group), or 100% oxygen (O(2) thoracotomy group) under mechanical ventilation for 2 h. Animals were sacrificed 2 h or 8 h after LPS administration, and inflammatory indices (plasma tumor necrosis factor-alpha and interleukin-6, histology) were examined. For examination of inflammatory mediators, pleural effusion was added to cultured RAW264 cells, a murine macrophage cell line, and tumor necrosis factor-alpha levels in supernatant were measured. The capacity of pleural superoxide generation was investigated without LPS administration. Results showed increases in plasma interleukin-6 concentration and lung injury in the air and O(2) thoracotomy groups. Pleural oxygen exposure stimulated pleural superoxide generation, and increased pleural 4-hydroxy-2-nonenal and lung lipid peroxide concentrations. Tumor necrosis factor-alpha levels in cell culture supernatants were increased by the addition of pleural effusion from the air and O(2) thoracotomy groups. In conclusion, pleural oxygen exposure induced pleural oxidative injury and aggravated latent systemic inflammatory response.

This review describes the role of oxidative stress caused by endotoxin challenge in sepsis or septic shock symptoms. We observed that endotoxin injection resulted in lipid peroxide formation and membrane damage (near 60-150 kDa) in the livers of experimental animals, causing decreased levels of scavengers or quenchers of free radicals. The administration of alpha-tocopherol completely prevented injury to the liver plasma membrane caused by endotoxin, and suggested that lipid peroxidation by free radicals might occur in a tissue ischemic state, probably by disseminated intravascular coagulation (DIC), in endotoxemia. In mice, depression of Ca(2+)-ATPase activity in the liver plasma membrane may contribute to the membrane damage caused by endotoxin, and the increase of [Ca(2+)](i) in the liver cytoplasm may partially explain the oxidative stress that occurs in endotoxemia. It seems that endotoxin-induced free radical formation is regulated by Ca(2+) mobilization. Moreover, we have suggested that the oxidative stress caused by endotoxin may be due, at least in part, to the changes in endogenous zinc or selenium regulation during endotoxemia. Interestingly, the extent of TNF-alpha-induced oxidative stress may be the result of a synergism between TNF-alpha and gut-derived endotoxin. It is likely that bacterial or endotoxin translocation plays a significant role in TNF-alpha-induced septic shock. On the other hand, although nitric oxide (NO) has been implicated in the pathogenesis of vascular hyporesponsiveness and hypotension in septic shock in our experimental model, it is unlikely that NO plays a significant role in liver injury caused by free radical generation in endotoxemia.

Cilostazol, a specific type-III phosphodiesterase inhibitor, is widely used for the treatment of ischemic symptoms of peripheral vascular disease. Recent studies have reported that the mechanism of cilostazol is related to the suppression of pro-inflammatory cytokine production and improvement of local microcirculation disturbances. The pathogenesis of stress-induced gastric mucosal lesions is characterized by the activation of inflammatory cells and the production of inflammatory cytokines. The effects of cilostazol on the development of gastric mucosal lesions have not been reported. In the present study, we examined the effect of a cilostazol on water-immersion stress-induced gastric mucosal lesions.

Rats were subjected to water-immersion stress with or without pretreatment with a single intraperitoneal injection of the selective type-III phosphodiesterase inhibitor, cilostazol. We measured the gastric mucosal lesion and the concentrations of myeloperoxidase (MPO), interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and cytokine-induced neutrophil chemoattractant-1 (GRO/CINC-1), as an index of neutrophil accumulation and pro-inflammatory cytokine production.

Cilostazol ameliorated the gastric mucosal injury induced by water-immersion stress (P<0.001). The gastric contents of MPO, TNF-alpha, IL-1beta, and CRO/CINC-1 were all increased after water-immersion stress and were reduced to almost normal levels by cilostazol.

In this study, we demonstrated that a selective type-III phosphodiesterase inhibitor, cilostazol, inhibited stress-induced gastric inflammation and damage via suppressing the production of pro-inflammatory cytokines. Cilostazol may be useful for preventing gastric mucosal lesions.

Inhibition of type IV phosphodiesterase (PDE IV) activity reduces the production of various proinflammatory cytokine and suppresses neutrophil activation. Nonsteroidal anti-inflammatory drugs such as aspirin induce gastric mucosal lesions. In the pathogenesis of aspirin-induced gastric mucosal lesion, the contributions, of activated inflammatory cells and proinflammatory cytokine production are critical. The specific PDE IV inhibitor rolipram is known to be a potent inhibitor of inflammation by increasing intracellular cyclic AMP in leukocytes. The aim of the present study was to determine whether rolipram can ameliorate aspirin-induced gastric mucosal lesions in rats and whether the agent can inhibit the inrease in neutrophil accumulation and the production of proinflammatory cytokines. Gastric lesions were produced by administration of aspirin (200 mg/kg) and HCI (0.15 N; 8.0 ml/kg). Rolipram was injected 30 min before aspirin administration. The tissue myeloperoxidase concentration in gastric mucosa was measured as an indicat or of neutrophil infiltration. The gastric mucosal concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) were determined by ELISA. The intragastric administration of aspirin induced multiple hemorrhagic erosions in rat gastric mucosa. Gastric mucosal lesions induced by aspirin were significantly inhibited by treatment with rolipram. The mucosal myeloperoxidase concentration was also suppressed by rolipram. Increases in the gastric content of TNF-alpha and IL-1beta after aspirin administration were inhibited by pretreatment with rolipram. We demonstrated that the specific type IV PDE inhibitor, rolipram, could have a potent antiulcer effect, presumably mediated by its anti-inflammatory properties.

Chronic hypoxia, viral infections/bacterial toxins, inflammation states, biochemical disorders, and genetic abnormalities are the most likely trigger of sudden infant death syndrome (SIDS). Autopsy studies have shown increased pulmonary density of macrophages and markedly more eosinophils in the lungs accompanied by increased T and B lymphocytes. The elevated levels of immunoglobulins, about 20% more muscle in the pulmonary arteries, increased airway smooth muscle cells, and increased fetal hemoglobin and erythropoietin are evidence of chronic hypoxia before death. Other abnormal findings included mucosal immune stimulation of the tracheal wall, duodenal mucosa, and palatine tonsils, and circulating interferon. Low normal or higher blood levels of cortisol often with petechiae on intrathoracic organs, depleted maternal IgG antibodies to endotoxin core (EndoCAb) and early IgM EndoCAb triggered, partial deletions of the C4 gene, and frequent IL-10-592*A polymorphism in SIDS victims as well as possible hypoxia-induced decreased production of antiinflammatory, antiimmune, and antifibrotic cytokine IL-10, may be responsible for the excessive reactions to otherwise harmless infections. In SIDS infants, during chronic hypoxia and times of infection/inflammation, several proinflammatory cytokines are released in large quantities, sometimes also representing a potential source of tissue damage if their production is not sufficiently well controlled, eg, by pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP). These proinflammatory cytokines down-regulate gene expression of major cytochrome P-450 and/or other enzymes with the specific effects on mRNA levels, protein expression, and enzyme activity, thus affecting metabolism of several endogenous lipophilic substances, such as steroids, lipid-soluble vitamins, prostaglandins, leukotrienes, thromboxanes, and exogenous substances. In SIDS victims, chronic hypoxia, TNF-alpha and other inflammatory cytokines, and arachidonic acid (AA) as well as n-3 polyunsaturated fatty acids (FA), stimulated and/or augmented superoxide generation by polymorphonuclear leukocytes, which contributed to tissue damage. Chronic hypoxia, increased amounts of nonheme iron in the liver and adrenals of these infants, enhanced activity of CYP2C9 regarded as the functional source of reactive oxygen species (ROS) in some endothelial cells, and nicotine accumulation in tissues also intensified production of ROS. These increased quantities of proinflammatory cytokines, ROS, AA, and nitric oxide (NO) also resulted in suppression of many CYP450 and other enzymes, eg, phosphoenolpyruvate carboxykinase (PEPCK), an enzyme important in the metabolism of FA during gluconeogenesis and glyceroneogenesis. PEPCK deficit found in SIDS infants (caused also by vitamin A deficiency) and eventually enhanced by PACAP lipolysis of adipocyte triglycerides resulted in an increased FA level in blood because of their impaired reesterification to triacylglycerol in adipocytes. In turn, the overproduction and release of FA into the blood of SIDS victims could lead to the metabolic syndrome and an early phase of type 2 diabetes. This is probably the reason for the secondary overexpression of the hepatic CYP2C8/9 content and activity reported in SIDS infants, which intensified AA metabolism. Pulmonary edema and petechial hemorrhages often present in SIDS victims may be the result of the vascular leak syndrome caused by IL-2 and IFN-alpha. Chronic hypoxia with the release of proinflammatory mediators IL-1alpha, IL-1beta and IL-6, and overloading of the cardiovascular and respiratory systems due to the narrowing airways and small pulmonary arteries of these children could also contribute to the development of these abnormalities. Moreover, chronic hypoxia of SIDS infants induced also production of hypoxia-inducible factor 1alpha (HIF-1alpha), which stimulated synthesis and release of different growth factors by vascular endothelial cells and intensified subclinical inflammatory reactions in the central nervous system, perhaps potentiated also by PACAP and VIP gene mutations. These processes could lead to the development of brainstem gliosis and disorders in the release of neuromediators important for physiologic sleep regulation. All these changes as well as eventual PACAP abnormalities could result in disturbed homeostatic control of the cardiovascular and respiratory responses of SIDS victims, which, combined with the nicotine effects and metabolic trauma, finally lead to death in these often genetically predisposed children.

Activation of adenosine A(2A) receptors reduces the production of various pro-inflammatory cytokines and suppresses neutrophil activation. Water-immersion restraint is well known to cause gastric mucosal lesions due to stress. The pathogenesis of stress-induced gastric mucosal lesions is characterized by activation of inflammatory cells and production of inflammatory cytokines. Agonists of adenosine A(2A) receptors are known to be anti-inflammatory, but the effects of these compounds on the development of gastric mucosal lesions has not been reported. In the present study, the effect of a potent and selective adenosine A(2A) receptor agonist, ATL-146e, on water-immersion stress-induced gastric mucosal lesions was studied.

Rats were subjected to water-immersion stress with or without pretreatment with a single intraperitoneal injection of a potent and selective agonist of the adenosine A(2A) receptor. The gastric concentrations of myeloperoxidase (MPO), as an index of neutrophil accumulation, and the pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), were measured.

The total length of gastric erosions (ulcer index) in control rats was 21.6 +/- 3.23 mm and was reduced by 86% to 3.1 +/- 0.83 mm by pretreatment with 5.0 microg/kg ATL146e (P < 0.001). The gastric content of MPO, TNF-alpha and IL-1beta were all increased after water-immersion stress and reduced to near normal levels by ATL-146e.

A specific adenosine A(2A) agonist inhibits stress-induced gastric inflammation and damage. A(2A) agonist compounds may be useful for preventing ulcers and appear to act by blocking gastric inflammation.

Inhibition of type IV phosphodiesterase activity is beneficial in various inflammation mediated by its function to suppress the production of inflammatory cytokines in inflammatory cells. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin are well known to develop gastric mucosal lesion. As pathogenesis of indomethacin induced gastric mucosal lesion, activation of neutrophils and inflammatory cytokine production play critical roles. However, the effect of phosphodiesterase inhibitors on development of gastric mucosal lesion has not been reported. In the present study, we examined the effect of specific type IV phosphodiesterase inhibitor (rolipram) on NSAIDs-induced gastric mucosal lesion. Also, we examined the effect of rolipram on tissue prostaglandin E2 (PGE2) production. Indomethacin-induced gastric mucosal injury was produced by the intragastric administration of indomethacin (30 mg/kg). Rolipram was injected to the rats intraperitoneally 30 min before the indomethacin administration. Ulcer index and tissue myeloperoxidase (MPO) activity of the gastric mucosa was evaluated. The gastric concentration of PGE2 was determined by RIA. Gastric mucosal lesion induced by indomethacin was significantly inhibited with treatment of rolipram. Mucosal MPO activity was also suppressed by administration of rolipram. Gastric mucosal PGE2 concentration was not affected by intraperitoneal injection of rolipram. Based on these data, the beneficial effects of rolipram on indomethacin-induced gastric mucosal injury may be attributed to its anti-inflammatory properties.

Satisfactory therapy for acute lung injury related to endotoxemia remains to be established. However, in vivo antioxidant treatment with N-acetylcysteine reportedly suppresses acute lung injury and proinflammatory cytokine production induced by endotoxin (lipopolysaccharide, LPS). In addition, intrinsic vitamin E is protective against LPS-induced insults. We determined the effects of a novel water-soluble vitamin E derivative, 2-(alpha-D-glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol (TMG), on acute lung injury and mortality induced by LPS in rats. Intravenous injection of TMG (4 or 40 mg/kg) effectively decreased mortality and prevented the increased alveolar permeability and pulmonary edema that were caused by intravenous injection of LPS (20 mg/kg). Treatment with TMG decreased the enhanced lung expression of TNF-alpha caused by LPS. TMG also suppressed the sequestration of neutrophils in the lung induced by LPS. These results indicate that TMG is a possible therapeutic agent for acute lung injury and mortality, especially that caused by gram-negative bacteria. The therapeutic effects could be mediated at least partly through suppression of the increased expression of TNF-alpha and neutrophil sequestration in the lung that are caused by LPS.

Tumour necrosis factor (TNF-alpha) is a candidate factor for involvement in inflammation-mediated gastric mucosal injury. However, the effect of this cytokine on gastric epithelial cells has been poorly investigated. In the present study, we examined whether gastric epithelial cells are resistant to TNF-alpha-induced apoptosis, and whether this resistance is related to ubiquitin-proteasome-associated nuclear factor-kappaB (NF-kappaB) activation.

The rat gastric mucosal cell line RGM-1 was grown in DMEM/F12 medium supplemented with 10% FCS. Confluent monolayers of cells were pretreated or not for 60 min with PSI, a peptide aldehyde known to specifically inhibit the chymotrypsin-like activity of 26S proteasome. Cells were subsequently stimulated with recombinant rat TNF-alpha and their viability was determined by WST-1 assay. Apoptosis was confirmed by fluorescence microscopy after staining with Hoechst 33342 and propidium iodide, and DNA fragmentation was determined by flow cytometry using an APO-BRDU kit. IkappaB-alpha and the p65 binding subunit of NF-kappaB were detected by Western blots.

Twenty-four-hour incubation with TNF-alpha alone or PSI alone did not affect the cell viability of RGM-1 cells. Pretreatment with PSI significantly enhanced the level of apoptosis induced by TNF-alpha. In RGM-1 cells treated with TNF-alpha, cytoplasmic IkappaB-alpha decreased and p65 in nuclear extracts increased markedly 30 min after cytokine stimulation. Pretreatment with PSI at 12.5 micromol/L blocked these TNF-alpha-induced changes.

PSI enhances TNF-alpha-induced apoptosis through inhibition of NF-kappaB activation in RGM-1 cells.

Neutrophils activation and tumour necrosis factor-alpha (TNF-alpha) induction play a critical role in aspirin-induced gastric mucosal injury. Peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a member of the nuclear hormone receptor superfamily, has recently been implicated as a regulator of inflammatory responses. The aim of the present study was to determine whether pioglitazone, a specific PPAR-gamma ligand, can ameliorate aspirin-induced gastric mucosal injury in rats, and whether the agent can inhibit the increase in neutrophil accumulation associated with TNF-alpha expression.

Aspirin-induced injury was produced by the intragastric administration of aspirin (200 mg/kg) and HCl (0.15 N, 8.0 mL/kg). Pioglitazone was given to the rats by gastric intubation 1 h before the aspirin administration. Thiobarbituric acid-reactive substances and tissue-associated myeloperoxidase activity were measured in gastric mucosa as indices of lipid peroxidation and neutrophil infiltration. The gastric concentration of TNF-alpha and the expression of TNF-alpha mRNA was determined by ELISA and reverse transcriptase-polymerase chain reaction.

The intragastric administration of acidified aspirin induced hyperemia and haemorrhagic erosions in rat stomachs. The increase in the total gastric erosive area after aspirin administration was significantly inhibited by treatment with pioglitazone in a dose-dependent manner. The increases in thiobarbituric acid-reactive substances and myeloperoxidase activity after aspirin administration were both significantly inhibited by pre-treatment with pioglitazone (10 mg/kg). The gastric content of TNF-alpha increased and the expression of TNF-alpha mRNA was up-regulated after aspirin treatment. However, the peak TNF-alpha mRNA expression 1 h after aspirin administration was inhibited by pioglitazone.

Based on these data, the beneficial effects of pioglitazone on aspirin-induced gastric mucosal injury may be attributed to its anti-inflammatory properties.

Gastric inflammation is a highly complex biochemical protective response to cellular/tissue injury. When this process occurs in an uncontrolled manner, the result is excessive cellular/tissue damage that results chronic inflammation and destruction of normal tissue. Current evidence suggests that Helicobacter pylori (H. pylori) infection and nonsteroidal anti-inflammatory drug (NSAID) ingestion are major causative factors in the pathogenesis of gastric mucosal injury in humans. In response to H. pylori infection or NSAID, neutrophils are recruited to the site of inflammation and generate reactive oxygen and nitrogen species and proteases. However, neutrophils are not able to kill the bacteria that live in the gastric mucus, and compounds produced by activated neutrophils themselves may be potentially harmful for normal tissue. It has been shown that leukocyte-vascular endothelial cell interaction is regulated by various cell adhesion molecules, and that this interaction is directly or indirectly modified by many factors, the origin of which is H. pylori and NSAIDs. This review describes the potential role of neutrophils and neutrophil-associated inflammation for gastric oxidative stress and injury induced by H. pylori and/or NSAID.

The enhancing effect of tumour necrosis factor-alpha (TNF-alpha) on oxidative stress with or without a sublethal dose of endotoxin was examined. The mortality of mice treated with recombinant human TNF-alpha (1 x 10(4) units/mouse, intravenously) and endotoxin (0.01-1 mg/kg, intraperitoneally) was dependent on the dose of endotoxin. The liver lipid peroxide level, superoxide anion generation and serum lactate dehydrogenase activity, especially serum lactate dehydrogenase-5 isozyme leakage, in mice 2-4 hr after administration of recombinant human TNF to endotoxin-pretreated mice (0.5 mg/kg, intraperitoneally) were markedly higher than in those without endotoxin, whereas the administration of recombinant human TNF significantly decreased the non-protein sulfhydryl level, superoxide dismutase and glutathione peroxide activities in the liver of endotoxin-injected mice compared with those in mice treated with recombinant human TNF or endotoxin alone. Furthermore, findings clearly demonstrated that J774A.1 cells stimulated with recombinant human TNF (1 x 10(4) units/ml) can effectively produce nitric oxide in the presence of endotoxin, and the production was dependent on the dose of endotoxin (0.01-10 micrograms/ml). The level of lipid peroxide in mice 4 hr after administration of recombinant human TNF and lead acetate (50 mg/kg, intravenously) was markedly higher than that in the mice treated with recombinant human TNF alone. By contrast, injection of polymyxin-B (20 mg/kg, intraperitoneally, an anti-endotoxin drug) markedly decreased the lipid peroxide level in the liver of the mice treated with recombinant human TNF and lead acetate. These findings suggest that the oxidative stress caused by TNF occurs as a enhancing effect of endotoxin or by bacterial translocation from the intestinal gut under reduction of reticuloendothelial system function in various disease states, and that the effect of TNF may cause a marked increase of toxicity of oxidative stress by endotoxin.

Superoxide and its derived active oxygen species are responsible for the polymorphonuclear leukocyte (PMN)-mediated tumoricidal activity which is typically shown in the intraperitoneal administration of OK-432, a biological response modifier, for cancer ascites. We examined the effects of intraperitoneal administration of OK-432 with or without syngeneic serum on superoxide generation from PMNs which migrated in the peritoneal cavity using the new method of Cypridina luciferin analog-dependent chemiluminescence for the detection of superoxide. PMNs harvested from rat peritoneal cavity 6 h after the intraperitoneal administration of OK-432 (0.25KE/kg, or 2.5KE/kg) generated larger amounts of superoxide than those harvested after intraperitoneal injection of oyster glycogen (75mg/kg) when stimulated by opsonized zymosan or phorbol myristate acetate. Simultaneous intraperitoneal administration of OK-432 and syngeneic serum induced a greater increase in PMN superoxide generation than OK-432 alone, which was reversed by a complement activation inhibitor (MX-1). Simultaneous injection of OK-432 and heat-inactivated syngeneic serum did not exhibit a significant increase in PMN superoxide generation as compared with OK-432 alone. These results provide pharmacological evidence to the satisfactory therapeutic effects of the intraperitoneal administration of OK-432 with or without serum for patients with cancer ascites, and indicate that complements, in particular C5a, are involved in this enhanced PMN-derived superoxide generation induced by the simultaneous injection of OK-432 and serum.