Prevention of NSAID-Induced Small Intestinal Mucosal Injury: Prophylactic Potential of Lansoprazole

Lansoprazole protects hepatic cells against cisplatin-induced oxidative stress through the p38 MAPK/ARE/Nrf2 pathway

Lansoprazole, a proton pump inhibitor, can exert antioxidant effects through the induction of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, independently of the inhibition of acid secretion in the gastrointestinal tract. Lansoprazole has been reported to provide hepatoprotection in a drug-induced hepatitis animal model through the Nrf2/heme oxygenase-1 (HO1) pathway. We sought to investigate the molecular mechanism of cytoprotection by lansoprazole. An in vitro experimental model was conducted using cultured rat hepatic cells treated with lansoprazole to analyze the expression levels of Nrf2 and its downstream genes, the activity of Nrf2 using luciferase reporter assays, cisplatin-induced cytotoxicity, and signaling pathways involved in Nrf2 activation. Lansoprazole treatment of rat liver epithelial RL34 cells induced transactivation of Nrf2 and the expression of the Nrf2-dependent antioxidant genes encoding HO1, NAD(P)H quinone oxidoreductase-1, and glutathione S-transferase A2. Furthermore, cycloheximide chase experiments revealed that lansoprazole prolongs the half-life of the Nrf2 protein. Notably, cell viability was significantly increased by lansoprazole treatment in a cisplatin-induced cytotoxicity model. Moreover, the siRNA knockdown of Nrf2 fully abolished the cytoprotective effect of lansoprazole, whereas the inhibition of HO1 by tin-mesoporphyrin only partially abolished this. Finally, lansoprazole promoted the phosphorylation of p38 mitogen-activated protein kinase (MAPK) but not that of the extracellular signal-regulated kinase or the c-Jun N-terminal kinase. Using SB203580, a specific inhibitor for p38 MAPK, the lansoprazole-induced Nrf2/antioxidant response elements pathway activation and cytoprotective effects were shown to be exclusively p38 MAPK dependent. Lansoprazole was shown by these results to exert a cytoprotective effect on liver epithelial cells against the cisplatin-induced cytotoxicity through the p38 MAPK signaling pathway. This could have potential applications for the prevention and treatment of oxidative injury in the liver.

The effect of rebamipide on non-steroidal anti-inflammatory drug-induced gastro-enteropathy: a multi-center, randomized pilot study

BACKGROUND/AIMS

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly-used medications, and ailments such as arthritis or heart disease, require long-term use of these drugs, which can induce gastroenteropathy with bleeding and ulcers. This study investigated the associations between efficacy, safety, and gastrointestinal symptoms linked to rebamipide and proton pump inhibitor administration in patients requiring long-term NSAID use.

METHODS

This study was a multi-center, randomized, open-labeled, pilot design.

RESULTS

Thirty-three patients were included. Of these, 15 were included in the study group and 18 were in the control group. NSAID-induced gastric ulcers, which were the primary outcome of this study, did not occur in either the study or control group. Changes in the number of small bowel erosions and ulcers were -0.6 ± 3.06 in the study group and 1.33 ± 4.71 in the control group. The number of subjects with mucosal breaks (defined as multiple erosions and/or ulcers) was three (20%) in the study group and six (40%) in the control group (p = 0.427). No serious adverse events occurred in either group. However, dyspepsia and skin rashes occurred in six patients (31.58%) in the study group and 13 (65%) in the control group (p = 0.036).

CONCLUSION

Although statistically significant differences were not generated, possibly as a result of the small sample size, mucosal breaks observed via capsule endoscopy revealed that rebamipide was likely to be more effective than lansoprazole in preventing small intestine damage caused by NSAIDs. Furthermore, fewer side-effects emerged with rebamipide.

Naproxen sodium nanoparticles are less toxic and gastroprotective agents than the conventional NSAID drug naproxen sodium in Balb/c mice

Use of non-steroidal anti-inflammatory drugs (NSAIDs) is one of the leading causes of gastric ulcers. Excellent therapeutic properties have made the use of NSAIDs widespread. Nano-drug delivery to reduce systemic toxicity through modulating drug pharmacokinetics may be a better choice. Presently, we investigated if naproxen nanoformulation (PVA capped NPRS-MgO NPs) is less toxic to be used as an alternative drug. Groups of mice were assigned to control, NPRS-treated, CNF-treated, UNF-treated, and MgO NPs-treated groups. Analyses included gross examination of gastric mucosa, calculation of ulcer and inhibition indices, determination of tissue levels of reactive oxygen species (ROS), malondialdehyde (MDA), catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and reduced glutathione (GSH), histological and immunohistochemical assessment of i-NOS, COX-2, and caspase-3 of stomach mucosa, q-PCR for the detection of mRNA expression of IL-1β, IL-6, and TNF-α. Results were compared statistically at P < 0.05. Compared to NPRS-treated mice which developed multiple ulcers, had elevated MDA and ROS levels, and deceased CAT, POD, SOD, and GSH levels, significantly increased expression of IL-1β, IL-6, and TNF-α mRNA, damaged surface epithelium with disrupted glandular architecture and leucocyte infiltration of lamina propria with a marked increase in mucosal COX-2, i-NOS, and caspase-3 expression, oral administration of coated and uncoated naproxen nanoformulations prevented the gross mucosal damage by a restoration of all biochemical, histological, and immunohistochemical alterations to near control levels. The present study demonstrates that naproxen sodium nanoformulation has a gastroprotective action and in the clinical setting can be a better alternative to conventional naproxen.

Indomethacin, a non-steroidal anti-inflammatory drug, induces skin dryness via PPARγ in mice

Cyclooxygenase (COX)-1-selective inhibitors have side effects such as itching and dryness of the skin. In this study, the degree of skin dryness and the onset mechanism of this condition were investigated by comparing the effects of three non-steroidal anti-inflammatory drugs (NSAIDs) in mice. Mice were orally administered either indomethacin, loxoprofen sodium, or celecoxib (n = 5 per group) once daily for four consecutive days, and blood samples as well as skin and jejunal tissues were isolated on day 5. In the mice treated with indomethacin, transepidermal water loss was significantly increased, and dry skin was observed. In addition, the expression of matrix metalloproteinase (MMP)-I, mast cells, CD163, CD23, CD21, histamine, and peroxisome proliferation-activated receptor (PPAR)γ in the skin and jejunum was increased, and the blood levels of interleukin-10 and immunoglobulin E were also increased. In contrast, the expression of collagen type I in the skin was decreased. These results show that indomethacin activates PPARγ in the skin and jejunum, changes the polarity of macrophages, increases the secretion of MMP-1 from mast cells, and decomposes collagen type I, leading to dry skin.

Gaseous Mediators as a Key Molecular Targets for the Development of Gastrointestinal-Safe Anti-Inflammatory Pharmacology

Non-steroidal anti-inflammatory drugs (NSAIDs) represent one of the most widely used classes of drugs and play a pivotal role in the therapy of numerous inflammatory diseases. However, the adverse effects of these drugs, especially when applied chronically, frequently affect gastrointestinal (GI) tract, resulting in ulceration and bleeding, which constitutes a significant limitation in clinical practice. On the other hand, it has been recently discovered that gaseous mediators nitric oxide (NO), hydrogen sulfide (H₂S) and carbon monoxide (CO) contribute to many physiological processes in the GI tract, including the maintenance of GI mucosal barrier integrity. Therefore, based on the possible therapeutic properties of NO, H₂S and CO, a novel NSAIDs with ability to release one or more of those gaseous messengers have been synthesized. Until now, both preclinical and clinical studies have shown promising effects with respect to the anti-inflammatory potency as well as GI-safety of these novel NSAIDs. This review provides an overview of the gaseous mediators-based NSAIDs along with their mechanisms of action, with special emphasis on possible implications for GI mucosal defense mechanisms.

Non-steroidal anti-inflammatory drug-induced enteropathy

Non-steroidal anti-inflammatory drugs (NSAIDs) are well known to be associated with serious upper gastrointestinal complications, such as peptic ulcer, bleeding, perforation, and obstruction. Recently, attention has been mainly focused on the small bowel injuries caused by NSAIDs, and new endoscopic techniques such as capsule endoscopy and double balloon endoscopy can help in detecting such injuries. This article reviewed the epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of small bowel injuries caused by NSAIDs. Small bowel injures by NSAIDs might occur with a similar frequency and extent as those observed in the upper gastrointestinal tract. The pathogenesis of NSAID-induced enteropathy is complex and not clearly understood. The various lesions observed in the small bowel, including petechiae, reddened folds, loss of villi, erosions, and ulcers can be detected by capsule endoscopy. A drug that could prevent or treat NSAID-induced enteropathy has not yet been developed. Therefore, further investigations should be performed to elucidate the pathogenesis of such enteropathy and develop suitable preventive and treatment strategies.

Proton pump inhibitor therapy did not increase the prevalence of small-bowel injury: A propensity-matched analysis

Background

Previous studies have reported that the suppression of acid secretion by using proton pump inhibitors (PPIs) results in dysbiosis of the small-bowel microbiota, leading to exacerbated small-bowel injuries, including erosions and ulcers. This study was designed to assess the association between PPI therapy and small-bowel lesions after adjustment for the differences in baseline characteristics between users and non-users of PPIs.

Methods

We retrospectively studied patients suspected to be suffering from small-bowel diseases, who underwent capsule endoscopy between 2010 and 2013. We used propensity matching to adjust for the differences in baseline characteristics between users and non-users of PPIs. The outcomes included the prevalence of small-bowel lesions: erosion, ulcer, angioectasia, varices, and tumor.

Results

We selected 327 patient pairs for analysis after propensity matching, and found no significant differences in the prevalence of small-bowel injuries, including erosions and ulcers, between users and non-users of PPIs. Two subgroup analyses of the effect of the type of PPI and the effect of PPI therapy in users and non-users of nonsteroidal anti-inflammatory drugs indicated no significant differences in the prevalence of small-bowel injuries in these two groups.

Conclusion

PPI therapy did not increase the prevalence of small-bowel injury, regardless of the type of PPI used and the use of nonsteroidal anti-inflammatory drugs.

Interaction between C-Reactive Protein and Phytochemical(s) from <i>Calotropis procera</i>: An Approach on Molecular Docking

The present study was attempted to detect potential phytoconstituents in C. procera against inflammation and pain. CRP is known to be increased up to 10,000 fold when acute inflammation take place in human. The interaction between C-reactive protein and phytochemical(s) from Calotropis procera was carried out with the help of molecular docking by using PyRx software (Ver. 0.8) and LigPlot software (Ver. 1.4) to compare energy value and binding site of phytochemicals in reference to established synthetic non-steroidal anti-inflammatory drugs (NSAIDs). The data suggest that the interaction between CRP and two phytochemicals namely methyl myrisate (-3.0) and methyl behenate (-3.2) showed close energy value (kcal/mol) and binding site in comparison to paracetamol (-3.9), ibobrufen (-4.2) while three phytochemicals viz. β-sitosterol (-5.6), uzarigenin (-5.5) and anthocyanins (-5.4) closely related to indomethacin (-5.2) in relation to energy value and binding site. In conclusion, based on molecular docking we found few phytochemicals of C. procera that can be used as lead compound(s) in future drug development as analgesic and anti-inflammatory agent at low cost. It is also suggested to carry out functional assay of predicted compounds to validate suitability of this lead.

Interaction between C-Reactive Protein and Phytochemical(s) from <i>Calotropis procera</i>: An Approach on Molecular Docking

The present study was attempted to detect potential phytoconstituents in C. procera against inflammation and pain. CRP is known to be increased up to 10,000 fold when acute inflammation take place in human. The interaction between C-reactive protein and phytochemical(s) from Calotropis procera was carried out with the help of molecular docking by using PyRx software (Ver. 0.8) and LigPlot software (Ver. 1.4) to compare energy value and binding site of phytochemicals in reference to established synthetic non-steroidal anti-inflammatory drugs (NSAIDs). The data suggest that the interaction between CRP and two phytochemicals namely methyl myrisate (-3.0) and methyl behenate (-3.2) showed close energy value (kcal/mol) and binding site in comparison to paracetamol (-3.9), ibobrufen (-4.2) while three phytochemicals viz. β-sitosterol (-5.6), uzarigenin (-5.5) and anthocyanins (-5.4) closely related to indomethacin (-5.2) in relation to energy value and binding site. In conclusion, based on molecular docking we found few phytochemicals of C. procera that can be used as lead compound(s) in future drug development as analgesic and anti-inflammatory agent at low cost. It is also suggested to carry out functional assay of predicted compounds to validate suitability of this lead.

Omeprazole induces heme oxygenase-1 in fetal human pulmonary microvascular endothelial cells via hydrogen peroxide-independent Nrf2 signaling pathway

Omeprazole (OM) is an aryl hydrocarbon receptor (AhR) agonist and a proton pump inhibitor that is used to treat humans with gastric acid related disorders. Recently, we showed that OM induces NAD (P) H quinone oxidoreductase-1 (NQO1) via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent mechanism. Heme oxygenase-1 (HO-1) is another cytoprotective and antioxidant enzyme that is regulated by Nrf2. Whether OM induces HO-1 in fetal human pulmonary microvascular endothelial cells (HPMEC) is unknown. Therefore, we tested the hypothesis that OM will induce HO-1 expression via Nrf2 in HPMEC. OM induced HO-1 mRNA and protein expression in a dose-dependent manner. siRNA-mediated knockdown of AhR failed to abrogate, whereas knockdown of Nrf2 abrogated HO-1 induction by OM. To identify the underlying molecular mechanisms, we determined the effects of OM on cellular hydrogen peroxide (H2O2) levels since oxidative stress mediated by the latter is known to activate Nrf2. Interestingly, the concentration at which OM induced HO-1 also increased H2O2 levels. Furthermore, H2O2 independently augmented HO-1 expression. Although N-acetyl cysteine (NAC) significantly decreased H2O2 levels in OM-treated cells, we observed that OM further increased HO-1 mRNA and protein expression in NAC-pretreated compared to vehicle-pretreated cells, suggesting that OM induces HO-1 via H2O2-independent mechanisms. In conclusion, we provide evidence that OM transcriptionally induces HO-1 via AhR - and H2O2 - independent, but Nrf2 - dependent mechanisms. These results have important implications for human disorders where Nrf2 and HO-1 play a beneficial role.

Uncovering the uncertainty: Risk factors and clinical relevance of P1 lesions on small bowel capsule endoscopy of anemic patients

AIM

To identify risk factors for P1 lesions on small bowel capsule endoscopy (SBCE) and to describe the natural history of anemic patients with such type of lesions.

METHODS

One hundred patients were consecutively selected for a case-control analysis performed between 37 cases with P1 lesions and 63 controls with negative SBCE. Age, gender, comorbidities and regular medication were collected. Rebleeding, further investigational studies and death were also analyzed during the follow-up.

RESULTS

No significant differences on gender, median age or Charlson index were found between groups. Although no differences were found on the use of proton pump inhibitors, acetylsalicylic acid, anticoagulants or antiplatelet agents, the use of non-steroidal anti-inflammatory drugs (NSAID) was associated with a higher risk of P1 lesions (OR = 12.00, 95%CI: 1.38-104.1). From the 87 patients followed at our center, 39 were submitted to additional studies for investigation of iron-deficiency anemia (IDA), and this was significantly more common in those patients with no findings on SBCE (53.7% vs 30.3%, P = 0.033). A total of 29 patients had at least one rebleeding or IDA recurrence episode and 9 patients died of non-anemia related causes but no differences were found between cases and controls.

CONCLUSION

P1 lesions are commonly found in patients with IDA submitted to SBCE. The use of NSAID seems to be a risk factor for P1 lesions. The outcomes of patients with P1 lesions do not differ significantly from those with P0 lesions or normal SBCE.

Proton Pump Inhibitors Increase Incidence of Nonsteroidal Anti-Inflammatory Drug-Induced Small Bowel Injury: A Randomized, Placebo-Controlled Trial

BACKGROUND & AIMS

Some studies have reported a high incidence of small bowel injuries in 60%-80% of subjects who take nonselective nonsteroidal anti-inflammatory drugs and PPIs simultaneously. We performed a randomized, double-blind, controlled study to determine whether proton pump inhibitors (PPIs) exacerbate nonsteroidal anti-inflammatory drug-induced small bowel injury.

METHODS

Fifty-seven healthy subjects were randomly assigned groups given the cyclooxygenase (COX) 2 inhibitor celecoxib (200 mg, twice daily) plus placebo for 2 weeks (COX-2 + placebo group, n = 30), or celecoxib plus the PPI rabeprazole (20 mg, once daily) for 2 weeks (COX-2 + PPI group, n = 27). The study was performed from October 2012 through September 2013 at a tertiary medical center in Japan. All subjects were evaluated by capsule endoscopy at the start of the study and then after 2 weeks administration of celecoxib with rabeprazole or placebo. The incidence rates and the numbers of small bowel injuries (ulcers and erosions) that were observed under capsule endoscopy were compared between groups. The primary endpoint was the incidence of mucosal injuries at the second capsule endoscopy examination.

RESULTS

A significantly higher proportion of subjects in the COX-2 + PPI group developed small bowel injury (12 of 27 subjects; 44.4%) than in the COX-2 + placebo group (5 of 30 subjects; 16.7%; P = .04). Subjects in the COX-2 + PPI group had a significant increase in risk of small bowel injury compared with the COX-2 + placebo group (relative risk, 2.67; 95% confidence interval, 1.08-6.58). The number of erosions in each member of the COX-2 + PPI group was greater than in each member of the COX-2 + placebo group (P = .02). The number of ulcers did not differ between groups. Twenty-six percent of subjects in the COX-2 + PPI group developed mucosal injury in the jejunum, compared with none of the subjects in the COX-2 + placebo group (P = .003); no such trend was found in the ileum.

CONCLUSIONS

In a randomized, controlled trial, PPIs increased the risk of short-term nonsteroidal anti-inflammatory drug-induced small bowel injury. UMIN clinical trial registry number: UMIN000008883.

Effect of proton-pump inhibitors on the risk of lower gastrointestinal bleeding associated with NSAIDs, aspirin, clopidogrel, and warfarin

BACKGROUND

We investigated the effects of proton-pump inhibitors (PPIs) on lower gastrointestinal bleeding (LGIB) and of their interactions with nonsteroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin, clopidogrel, and warfarin on LGIB risk.

METHODS

We prospectively studied 355 patients emergently hospitalized for LGIB and 8,221 nonbleeding patients. All patients underwent colonoscopy. Smoking, alcohol drinking, drug exposure, and the Charlson comorbidity index score were assessed before colonoscopy. Adjusted odds ratios (AOR) of LGIB were estimated.

RESULTS

LGIB was significantly associated with older age, higher comorbidity index, and NSAID, aspirin, clopidogrel, or warfarin use. PPI use was significantly associated with older age, male sex, being a current alcohol drinker, higher comorbidity index, and NSAID, aspirin, clopidogrel, warfarin, acetaminophen, or corticosteroid use. Multivariate analysis adjusted by the confounding factors revealed LGIB was not significantly associated with PPI use (AOR 0.87; 95 % confidence interval 0.68-1.13; p = 0.311), or specifically with omeprazole (AOR 1.18; p = 0.408), esomeprazole (AOR 0.76; p = 0.432), lansoprazole (AOR 0.93; p = 0.669), or rabeprazole (AOR 0.63; p = 0.140). In the interaction model, no significant interactions were observed between PPIs and NSAIDs (AOR 1.40; p = 0.293), aspirin (AOR 1.09; p = 0.767), clopidogrel (AOR 0.99, p = 0.985), or warfarin (AOR 1.52; p = 0.398).

CONCLUSIONS

This large case-control study demonstrated that PPI use did not lead to an increased risk of LGIB, regardless of the type of PPI used. Further, LGIB risk was not affected by PPI use, irrespective of concomitant therapy with NSAIDs, low-dose aspirin, clopidogrel, or warfarin.

Renoprotective effect of lansoprazole in streptozotocin-induced diabetic nephropathy in wistar rats

Proton pump inhibitors (PPIs) have exhibited glucose lowering action in animal models of diabetes; however, their potential in diabetes-related complications has not yet been evaluated. Hence, the present study has been undertaken to investigate the renoprotective potential of lansoprazole in streptozotocin-induced diabetic nephropathy in wistar rats. Diabetic nephropathy was induced with a single injection of streptozotocin (STZ, 45 mg/kg, i.p.). Lansoprazole (40 mg/kg; 80 mg/kg, p.o.; 4 weeks) was administered to diabetic rats after 4 weeks of STZ treatment. A battery of biochemical tests such as serum glucose, glycated hemoglobin, blood urea nitrogen (BUN), serum creatinine, albumin, and kidney weight/body weight (%) ratio were performed to evaluate the renal functions. Oxidative stress was determined by estimating renal thiobarbituric acid reactive species (TBARS) and reduced glutathione (GSH) levels. Lipid profile was assessed by determining serum cholesterol (TC), triglyceride (TG), and high-density lipoprotein (HDL). The STZ-treated rats demonstrated deleterious alterations in kidney functions, enhanced oxidative stress, and disturbed lipid profile. Administration of lansoprazole to diabetic rats significantly reduced serum glucose, glycated hemoglobin, BUN, creatinine, albumin levels, and oxidative stress. Serum lipids like TC and TG were decreased, and HDL was enhanced in lansoprazole-treated STZ rats. The findings of our study indicate that renoprotective effects of lansoprazole may be attributed to its glucose-lowering, lipid-lowering, and antioxidative potential.

Small bowel injury in low-dose aspirin users

The use of low-dose aspirin (LDA) is well known to be associated with an increased risk of serious upper gastrointestinal complications, such as peptic ulceration and bleeding. Until recently, attention was mainly focused on aspirin-induced damage of the stomach and duodenum. However, recently, there has been growing interest among gastroenterologists on the adverse effects of aspirin on the small bowel, especially as new endoscopic techniques, such as capsule endoscopy (CE) and balloon-assisted endoscopy, have become available for the evaluation of small bowel lesions. Preliminary CE studies conducted in healthy subjects have shown that short-term administration of LDA can induce mild mucosal inflammation of the small bowel. Furthermore, chronic use of LDA results in a variety of lesions in the small bowel, including multiple petechiae, loss of villi, erosions, and round, irregular, or punched-out ulcers. Some patients develop circumferential ulcers with stricture. In addition, to reduce the incidence of gastrointestinal lesions in LDA users, it is important for clinicians to confirm the differences in the gastrointestinal toxicity between different types of aspirin formulations in clinical use. Some studies suggest that enteric-coated aspirin may be more injurious to the small bowel mucosa than buffered aspirin. The ideal treatment for small bowel injury in patients taking LDA would be withdrawal of aspirin, however, LDA is used as an antiplatelet agent in the majority of patients, and its withdrawal could increase the risk of cardiovascular/cerebrovascular morbidity and mortality. Thus, novel means for the treatment of aspirin-induced enteropathy are urgently needed.

Protective role of hemeoxygenase-1 in gastrointestinal diseases

Disorders and diseases of the gastrointestinal system encompass a wide array of pathogenic mechanisms as a result of genetic, infectious, neoplastic, and inflammatory conditions. Inflammatory diseases in general are rising in incidence and are emerging clinical problems in gastroenterology and hepatology. Hemeoxygenase-1 (HO-1) is a stress-inducible enzyme that has been shown to confer protection in various organ-system models. Its downstream effectors, carbon monoxide and biliverdin have also been shown to offer these beneficial effects. Many studies suggest that induction of HO-1 expression in gastrointestinal tissues and cells plays a critical role in cytoprotection and resolving inflammation as well as tissue injury. In this review, we examine the protective role of HO-1 and its downstream effectors in modulating inflammatory diseases of the upper (esophagus and stomach) and lower (small and large intestine) gastrointestinal tract, the liver, and the pancreas. Cytoprotective, anti-inflammatory, anti-proliferative, antioxidant, and anti-apoptotic activities of HO-1 make it a promising if not ideal therapeutic target for inflammatory diseases of the gastrointestinal system.

Amelioration of small bowel injury by switching from nonselective nonsteroidal anti-inflammatory drugs to celecoxib in rheumatoid arthritis patients: a pilot study

BACKGROUND/AIMS

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used in patients with rheumatoid arthritis (RA) but have several side effects including mucosal damage in the small intestine. We aimed to evaluate whether the small bowel injury is ameliorated by switching from nonselective NSAIDs to celecoxib in patients with RA.

METHODS

Sixteen patients with RA who were treated with nonselective NSAIDs were enrolled in this study. Nonselective NSAIDs were converted to celecoxib for 12 weeks. Capsule endoscopy was performed before and after treatment with celecoxib. Videos were screened by gastroenterologists blinded to the patients' treatment.

RESULTS

Before the administration of celecoxib, reddened folds, denuded areas, petechiae/red spots and mucosal breaks were observed in 63, 63, 88 and 69% of the patients, respectively. In the 14 patients who completed this study, conversion to celecoxib significantly reduced the number of petechiae/red spots, the number of mucosal breaks, and Lewis scores. RA activity and cytokine levels in the peripheral blood were not significantly different before and after treatment with celecoxib.

CONCLUSIONS

The incidence of small bowel injury by nonselective NSAIDs is high in patients with RA. Conversion from nonselective NSAIDs to celecoxib can be useful for protecting patients with RA from small bowel injury.

Risk factors for small-bowel mucosal breaks in chronic low-dose aspirin users: data from a prospective multicenter capsule endoscopy registry

BACKGROUND

To develop appropriate management strategies for patients who take low-dose aspirin, it is important to identify the risk factors for GI injury. However, few studies have described the risk factors for small-bowel injury in these patients.

OBJECTIVE

To investigate factors influencing the risk of small-bowel mucosal breaks in individuals taking continuous low-dose aspirin.

DESIGN

Capsule endoscopy data were collected prospectively from 5 institutions.

SETTING

Yokohama City University Hospital and 4 other hospitals.

PATIENTS

A total of 205 patients receiving treatment with low-dose aspirin for over 3 months.

INTERVENTIONS

Colonoscopic and upper GI endoscopy had been performed in all of the patients before the capsule endoscope evaluation.

MAIN OUTCOME MEASUREMENTS

Risk factors for small-bowel mucosal breaks.

RESULTS

Of the 198 patients (141 male; mean age 71.9 years) included in the final analysis, 114 (57.6%) had at least 1 mucosal break. Multivariate analysis identified protein pump inhibitor (PPI) use (OR 2.04; 95% confidence interval [CI], 1.05-3.97) and use of enteric-coated aspirin (OR 4.05; 95% CI, 1.49-11.0) as independent risk factors for the presence of mucosal breaks.

LIMITATIONS

Cross-sectional study.

CONCLUSION

PPI use appears to increase the risk of small-bowel injury in patients who take continuous low-dose aspirin. Clinicians should be aware of this effect of PPIs; new strategies are needed to treat aspirin-induced gastroenteropathy.

Down-regulation of collagen I biosynthesis in intestinal epithelial cells exposed to indomethacin: a comparative proteome analysis

In contrast to accumulated knowledge about gastroduodenal injury associated with nonsteroidal antiinflammatory drugs (NSAIDs) such as indomethacin, small intestinal mucosal injuries have been noticed only recently, and the precise mechanism remains to be elucidated. To clarify the mechanism, we performed 2-DE on IEC-6 rat normal intestinal cells that were treated with indomethacin (200μΜ, 24h) or a vehicle control and identified 18 up-regulated and 8 down-regulated proteins through MALDI-TOF/TOF mass spectrometry. Among these proteins, collagen I and proteins involved in collagen I biosynthesis and maturation, including prolyl 4-hydroxylase subunit α1, protein disulfide isomerase A3 (PDIA3), calreticulin, and endoplasmin, were all down-regulated by indomethacin. Immunohistochemical staining of the intestinal mucosa of indomethacin-administered rats showed a decrease of collagen I on the apical surface of intestinal cells. Cell death induced by indomethacin was prominently suppressed when IEC-6 cells were grown on collagen I-coated plates. cis-4-Hydroxy-l-proline, a proline analog that inhibits collagen synthesis, depressed IEC-6 cell viability in a concentration-dependent manner. Cell death was also induced by short interfering RNA knockdown of endogenous collagen I in IEC-6 cells. In conclusion, by comparative proteome analysis, we identified down-regulation of collagen I as an important mechanism in NSAID-induced intestinal injury.

BIOLOGICAL SIGNIFICANCE

Small intestinal lesions induced by NSAIDs are of great concern in clinical settings. Various hypotheses have been proposed for the origin of these inflammatory responses, such as reduction in the blood flow, intestinal hypermotility, abnormal intestinal mucosal permeability, mitochondrial dysfunction, and reactive oxygen species, many of which are related to the inhibition of prostaglandin synthesis. However, the precise mechanism is yet to be known. The cellular process of the lesions must involve up- and down-regulations of a large number of proteins and complex interactions between them. To elucidate it, global and systematic identification of the proteins in intestinal cells affected by NSAIDs is essential. We found that the proteins exhibiting reduced expression by indomethacin treatment are collagen I and the proteins involved in collagen I synthesis and maturation. Consistent with this, immunohistochemical analysis showed that the indomethacin-treated rat intestinal mucosal cells exhibits decreased collagen I expression on its apical surface. Furthermore, the cell-protective effect of collagen on intestinal mucosal cells was demonstrated by the use of a collagen-synthesis inhibitor, short interfering RNA (siRNA) knockdown of endogenous collagen I, and cell cultivation on collagen I-coated plates versus uncoated plates. These results give important information on the role of the collagen synthesis in intestinal mucosa in the mechanism of NSAID-induced small intestinal lesions.

Preventive effect of agaro-oligosaccharides on non-steroidal anti-inflammatory drug-induced small intestinal injury in mice

BACKGROUND AND AIM

Non-steroidal anti-inflammatory drugs (NSAIDs), which are commonly used in clinical medicine, cause erosion, ulcers, and bleeding in the gastrointestinal tract. No effective agent for the prevention and treatment of small intestinal injury by NSAIDs has been established. This study investigates the effects of agaro-oligosaccharides (AGOs) on NSAID-induced small intestinal injury in mice.

METHODS

Mice were treated with indomethacin, an NSAID, to induce intestinal injury. The respective degrees of mucosal injury of mice that received AGO and control mice were compared. Heme oxygenase-1 (HO-1) expression using quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting, and immunohistochemistry were measured. The expression of keratinocyte chemoattractant (KC) was measured using qRT-PCR and enzyme-linked immunosorbent assay.

RESULTS

AGO administration induced HO-1 expression in mouse small intestinal mucosa. Induction was observed mainly in F4/80 positive macrophages. The increased ulcers score, myeloperoxidase activity, and KC expression by indomethacin were inhibited by AGO administration. Conversely, HO inhibitor cancelled AGO-mediated prevention of intestinal injury. In mouse peritoneal macrophages, AGOs enhanced HO-1 expression and suppressed lipopolysaccharide-induced KC expression. Furthermore, AGOs enhanced the expressions of alternatively activated macrophage markers arginase-1, mannose receptor-1, and chitinase 3-like 3.

CONCLUSIONS

Results suggest that oral administration of AGOs prevents NSAID-induced intestinal injury.

Exacerbation of nonsteroidal anti-inflammatory drug-induced small intestinal lesions by antisecretory drugs in rats: the role of intestinal motility

Antisecretory drugs such as histamine H2-receptor antagonists (H2-RAs) and proton pump inhibitors (PPIs) are commonly used for the treatment of gastric and duodenal ulcers induced by nonsteroidal anti-inflammatory drugs (NSAIDs). However, the effects of these drugs on NSAID-induced small intestinal ulcers are not fully understood. The effects of H2-RAs and PPIs on NSAID-induced gastrointestinal lesions and small intestinal motility were examined in rats. Male Wistar rats (180-220 g) were used. Indomethacin (10 mg/kg) was administered orally in fasted or fed rats, and gastrointestinal lesions were examined 24 h after indomethacin administration. Intestinal motility was measured by using a balloon method under urethane anesthesia. Indomethacin produced multiple lesions in the gastric corpus in fasted rats and in the small intestine in fed rats: 1) H2-RAs (cimetidine, ranitidine, and famotidine) and PPIs (omeprazole, lansoprazole, and rabeprazole) markedly inhibited the formation of gastric lesions. 2) The drugs, except for lansoprazole, increased intestinal lesions. 3) H2-RAs augmented the increase in intestinal motility caused by indomethacin, and the effects of H2-RAs on motility and intestinal lesions were markedly inhibited by atropine. 4) Lansoprazole inhibited the formation of intestinal lesions, and the effect was prevented by both pharmacological ablation of capsaicin-sensitive sensory neurons and pretreatment with N-nitro-l-arginine methyl ester, a selective inhibitor of nitric-oxide synthesis. The results suggest that: 1) inhibition of acid secretion by antisecretory drugs may exacerbate NSAID-induced intestinal lesions, 2) H2-RAs further aggravate lesions by increasing intestinal motility via the activation of cholinergic pathways, and 3) lansoprazole protects the intestinal mucosa against NSAID-related ulcerative stimuli.

Decreased leukocyte recruitment by inorganic nitrate and nitrite in microvascular inflammation and NSAID-induced intestinal injury

Nitric oxide (NO) generated by vascular NO synthases can exert anti-inflammatory effects, partly through its ability to decrease leukocyte recruitment. Inorganic nitrate and nitrite, from endogenous or dietary sources, have emerged as alternative substrates for NO formation in mammals. Bioactivation of nitrate is believed to require initial reduction to nitrite by oral commensal bacteria. Here we investigated the effects of inorganic nitrate and nitrite on leukocyte recruitment in microvascular inflammation and in NSAID-induced small-intestinal injury. We show that leukocyte emigration in response to the proinflammatory chemokine MIP-2 is reduced by 70% after 7 days of dietary nitrate supplementation as well as by acute intravenous nitrite administration. Nitrite also reduced leukocyte adhesion to a similar extent and this effect was inhibited by the soluble guanylyl cyclase inhibitor ODQ, whereas the effect on emigrated leukocytes was not altered by this treatment. Further studies in TNF-α-stimulated endothelial cells revealed that nitrite dose-dependently reduced the expression of ICAM-1. In rats and mice subjected to a challenge with diclofenac, dietary nitrate prevented the increase in myeloperoxidase and P-selectin levels in small-intestinal tissue. Antiseptic mouthwash, which eliminates oral nitrate reduction, markedly blunted the protective effect of dietary nitrate on P-selectin levels. Despite attenuation of the acute immune response, the overall ability to clear an infection with Staphylococcus aureus was not suppressed by dietary nitrate as revealed by noninvasive IVIS imaging. We conclude that dietary nitrate markedly reduces leukocyte recruitment to inflammation in a process involving attenuation of P-selectin and ICAM-1 upregulation. Bioactivation of dietary nitrate requires intermediate formation of nitrite by oral nitrate-reducing bacteria and then probably further reduction to NO and other bioactive nitrogen oxides in the tissues.

Traditional Herbal Medicine, Rikkunshito, Induces HSP60 and Enhances Cytoprotection of Small Intestinal Mucosal Cells as a Nontoxic Chaperone Inducer

Increasing incidence of small intestinal ulcers associated with nonsteroidal anti-inflammatory drugs (NSAIDs) has become a topic with recent advances of endoscopic technology. However, the pathogenesis and therapy are not fully understood. The aim of this study is to examine the effect of Rikkunshito (TJ-43), a traditional herbal medicine, on expression of HSP60 and cytoprotective ability in small intestinal cell line (IEC-6). Effect of TJ-43 on HSP60 expression in IEC-6 cells was evaluated by immunoblot analysis. The effect of TJ-43 on cytoprotective abilities of IEC-6 cells against hydrogen peroxide or indomethacin was studied by MTT assay, LDH-release assay, caspase-8 activity, and TUNEL. HSP60 was significantly induced by TJ-43. Cell necrosis and apoptosis were significantly suppressed in IEC-6 cells pretreated by TJ-43 with overexpression of HSP60. Our results suggested that HSP60 induced by TJ-43 might play an important role in protecting small intestinal epithelial cells from apoptosis and necrosis in vitro.

Evidence for enhanced cytoprotective function of HSP90-overexpressing small intestinal epithelial cells

BACKGROUND

In the clinical field, increasing incidence of small intestinal ulcers associated with nonsteroidal anti-inflammatory drugs (NSAIDs) has become a topic with the advances of capsule endoscopy and balloon enteroscopy technology for the detection of small intestinal lesions. However, the pathogenesis of NSAID-induced mucosal damage, defensive mechanism of intestinal epithelial cells, and therapy for small intestinal mucosal lesion have not been fully understood. Heat shock proteins (HSPs) are involved in cytoprotection mediated by their function as a molecular chaperone. Since the function of HSP90 in the intestinal epithelial cells has not been well investigated, we examined the cytoprotective ability of HSP90-overexpressing small intestinal epithelial cells against hydrogen peroxide-induced or indomethacin-induced cell damage.

METHODS

cDNA of human HSP90 gene was transfected to rat small intestinal epithelial cells (IEC-6 cells), and HSP90-overexpressing cells (IEC-6-90 cells) were selected and cloned. Anti-necrotic abilities and anti-apoptotic abilities of IEC-6-90 cells were compared with IEC-6-mock cells (transfected with vector alone). To examine the specific contribution of HSP90 on cytoprotection of IEC-6-90 cells, cytoprotective ability of IEC-6-90 cells was analyzed with or without pretreatment with functional inhibitor of HSP90, geldanamycine analog, followed by hydrogen peroxide-challenge or indomethacin-challenge.

RESULTS

Hydrogen peroxide-induced or indomethacin-induced cell necrosis and apoptosis were significantly suppressed in IEC-6-90 cells. The cytoprotective ability of IEC-6-90 cells was suppressed by HSP90 inhibitor.

CONCLUSIONS

Our results suggest that HSP90 might play an important role in protecting small intestinal epithelial cells from hydrogen peroxide-induced or indomethacin-induced cell injury in vitro, and raised the possibility of protection of small intestinal epithelial cells by manipulation of HSP90 expression.

Evaluation of gastrointestinal injury and blood flow of small bowel during low-dose aspirin administration

Low-dose acetylsalicylic acid has been widely used. We evaluated small bowel and gastric injuries during acetylsalicylic acid administration using video capsule endoscopy and gastroduodenal endoscopy. We also investigated blood flow using contrast-enhanced ultrasonography. Six healthy volunteers were enrolled in this preliminary study. The subjects were administered 100 mg of enteric-coated aspirin daily for 14 days. Video capsule endoscopy and gastroduodenal endoscopy were simultaneously performed before administration and on days 1, 3, 7 and 14. Contrast-enhanced ultrasonography was performed before administration and on day 2, and 8. Video capsule endoscopy after administration of low-dose acetylsalicylic acid revealed small bowel mucosal damages of petechiae and erythema in all cases, and denuded area in one case. The total number of lesions in the small bowel increased according to duration of low-dose acetylsalicylic acid administration. However, the total number of lesions in the stomach peaked on day 3. Contrast-enhanced ultrasonography showed that the time-intensity curve peak value and Areas under the curves after acetylsalicylic acid administration were reduced. We observed not only gastric mucosal injuries but also small intestinal injuries with short-term low-dose acetylsalicylic acid administration. Acetylsalicylic acid administration also caused a decrease in small intestinal blood flow. Contrast-enhanced ultrasonography is useful for evaluation blood flow in the small bowel mucosa.

Identification of dihalogenated proteins in rat intestinal mucosa injured by indomethacin

Previous studies have shown that activated neutrophils and their myeloperoxidase (MPO)-derived products play a crucial role in the pathogenesis of non-steroidal anti-inflammatory drug (NSAID)-related small intestinal injury. The aim of the present study is to identify dihalogenated proteins in the small intestine on indomethacin administration. Intestinal damage was induced by subcutaneous administration of indomethacin (10 mg/kg) in male Wistar rats, and the severity of the injury was evaluated by measuring the area of visible ulcerative lesions. Tissue-associated MPO activity was measured in the intestinal mucosa as an index of neutrophil infiltration. The dihalogenated proteins were separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) using novel monoclonal antibodies against dibromotyrosine (DiBrY), and they were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) peptide mass fingerprinting and a Mascot database search. Single administration of indomethacin elicited increased ulcerative area and MPO activity in the small intestine. 2D-PAGE showed an increased level of DiBrY-modified proteins in the indomethacin-induced injured intestinal mucosa and 6 modified proteins were found. Enolase-1 and albumin were found to be DiBrY modified. These proteins may be responsible for the development of neutrophil-associated intestinal injury induced by indomethacin.

Mitochondrial disorders in NSAIDs-induced small bowel injury

Recent studies using small bowel endoscopy revealed that non-steroidal anti-inflammatory drugs including low-dose aspirin, can often induce small bowel injury. Non-steroidal anti-inflammatory drugs-induced small bowel mucosal injury involves various factors such as enterobacteria, cytokines, and bile. Experimental studies demonstrate that both mitochondrial disorders and inhibition of cyclooxygenases are required for development of non-steroidal anti-inflammatory drugs-induced small bowel injury. Mitochondrion is an organelle playing a central role in energy production in organisms. Many non-steroidal anti-inflammatory drugs directly cause mitochondrial disorders, which are attributable to uncoupling of oxidative phosphorylation induced by opening of the mega channel called mitochondrial permeability transition pore on the mitochondrial membrane by non-steroidal anti-inflammatory drugs. Bile acids and tumor necrosis factor-α also can open the permeability transition pore. The permeability transition pore opening induces the release of cytochrome c from mitochondrial matrix into the cytosol, which triggers a cascade of events that will lead to cell death. Therefore these mitochondrial disorders may cause disturbance of the mucosal barrier function and elevation of the small bowel permeability, and play particularly important roles in early processes of non-steroidal anti-inflammatory drugs-induced small bowel injury. Although no valid means of preventing or treating non-steroidal anti-inflammatory drugs-induced small bowel injury has been established, advances in mitochondrial studies may bring about innovation in the prevention and treatment of this kind of injury.

Heme oxygenase-1: a novel therapeutic target for gastrointestinal diseases

Heme oxygenase-1 (HO-1) is the rate-limiting enzyme in the catabolism of heme, followed by production of biliverdin, free iron and carbon monoxide (CO). HO-1 is a stress-responsive protein induced by various oxidative agents. Recent studies demonstrate that the expression of HO-1 in response to different inflammatory mediators may contribute to the resolution of inflammation and has protective effects in several organs against oxidative injury. Although the mechanism underlying the anti-inflammatory actions of HO-1 remains poorly defined, both CO and biliverdin/bilirubin have been implicated in this response. In the gastrointestinal tract, HO-1 is shown to be transcriptionally induced in response to oxidative stress, preconditioning and acute inflammation. Recent studies suggest that the induction of HO-1 expression plays a critical protective role in intestinal damage models induced by ischemia-reperfusion, indomethacin, lipopolysaccharide-associated sepsis, trinitrobenzene sulfonic acid, and dextran sulfate sodium, indicating that activation of HO-1 may act as an endogenous defensive mechanism to reduce inflammation and tissue injury in the gastrointestinal tract. In addition, CO derived from HO-1 is shown to be involved in the regulation in gastro-intestinal motility. These in vitro and in vivo data suggest that HO-1 may be a novel therapeutic target in patients with gastrointestinal diseases.

The pathophysiology of non-steroidal anti-inflammatory drug (NSAID)-induced mucosal injuries in stomach and small intestine

Non-steroidal anti-inflammatory drugs are the most commonly prescribed drugs for arthritis, inflammation, and cardiovascular protection. However, they cause gastrointestinal complications. The pathophysiology of these complications has mostly been ascribed to non-steroidal anti-inflammatory drugs’ action on the cyclooxygenase inhibition and the subsequent prostaglandin deficiency. However, recent clinical demonstrated the prevalence of non-steroidal anti-inflammatory drugs-induced small intestinal mucosal injury is more often than previously expected. In this review, we discuss the defense mechanisms of stomach, and the pathophysiology of non-steroidal anti-inflammatory drugs-induced injury of stomach and small intestine, especially focused on non-steroidal anti-inflammatory drugs’ action on mitochondria.

The role of heme oxygenase and carbon monoxide in inflammatory bowel disease

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease, is a chronic and recurrent inflammatory disorder of the intestinal tract. Since the precise pathogenesis of IBD remains unclear, it is important to investigate the pathogenesis of IBD and to evaluate new anti-inflammatory strategies. Recent evidence suggests that heme oxygenase-1 (HO-1) plays a critical protective role during the development of intestinal inflammation. In fact, it has been demonstrated that the activation of HO-1 may act as an endogenous defensive mechanism to reduce inflammation and tissue injury in various animal intestinal injury models induced by ischemia-reperfusion, indomethacin, lipopolysaccharide-associated sepsis, trinitrobenzene sulfonic acid or dextran sulfate sodium. In addition, carbon monoxide (CO) derived from HO-1 has been shown to be involved in the regulation of intestinal inflammation. Furthermore, administration of a low concentration of exogenous CO has a protective effect against intestinal inflammation. These data suggest that HO-1 and CO may be novel therapeutic molecules for patients with gastrointestinal inflammatory diseases. In this review, we present what is currently known regarding the role of HO-1 and CO in intestinal inflammation.

Reduced small-intestinal injury induced by indomethacin in interleukin-17A-deficient mice

BACKGROUND AND AIMS

The pathogenesis of enteropathy induced by non-steroidal anti-inflammatory drugs (NSAIDs) is still unclear, and there are no established treatments. Interleukin-17A (IL-17A) is a pro-inflammatory cytokine that has been associated with the development of chronic inflammatory diseases, including autoimmune diseases. To define the role of IL-17A in small intestinal injury and inflammation, we studied the effects of indomethacin administration in mice with targeted deletions of the IL-17A gene.

METHODS

Male C57BL/6 (wild-type) and homozygous IL-17A(-/-) C57BL/6 mice were subjected to this study. Indomethacin (10 mg/kg) was subcutaneously administered to induce small-intestinal damage. Indomethacin-induced lesions in the small intestine were evaluated by measuring the injured area and by histopathology. Also assessed were myeloperoxidase (MPO) activity, as an index of neutrophil accumulation, and intestinal mRNA expression for inflammatory cytokines.

RESULTS

The area of macroscopic ulcerative lesions, the MPO activity and the mRNA expression of inflammatory-associated chemokines, such as keratinocyte chemoattractant (KC), monocyte chemotactic protein-1 (MCP-1), and granulocyte-colony stimulating factor (G-CSF), were significantly increased in indomethacin-treated groups compared with the sham groups. The development of intestinal lesions by indomethacin was inhibited in IL-17A(-/-) mice compared with wild-type mice, together with significant suppression of the increased levels of MPO activities and KC, MCP-1, and G-CSF levels.

CONCLUSION

These findings demonstrate that IL-17A contributes to the development of indomethacin-induced small intestinal injury through upregulation of G-CSF, KC, and MCP-1. IL-17A might be a promising new therapeutic target to treat NSAID-induced enteritis.

Distribution of small intestinal mucosal injuries as a result of NSAID administration

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce small intestinal mucosal injuries. The concentrations of NSAIDs, bile acids and intestinal flora may differ in the proximal and distal parts of the small intestine. This study aimed to analyse types and distributions of NSAID-induced small intestinal injuries.

SUBJECTS AND METHODS

In total 55 healthy male volunteers were examined using baseline capsule endoscopy (CE). Subjects then undertook a 14-day regimen of NSAID medication (diclofenac sodium, 75 mg day(-1)) with proton-pump inhibitors (omeprazole 20 mg day(-1)) as gastroprotection. After 14 days, subjects underwent post-treatment CE and were assessed for three types of small intestinal injuries: denuded areas, erosions and ulcers. The proximal and distal parts of the small intestine were arbitrarily classified according to CE transit time from the duodenal bulb.

RESULTS

Baseline CE revealed six mucosal lesions in 6 of 55 subjects (11%), consisting of three denuded areas and three erosions. Post-treatment CE identified 636 lesions in 32 of 53 subjects (60%); including 115 denuded areas in 16 subjects, 498 erosions in 22 subjects and 23 ulcers in 8 subjects. The distribution of small intestinal injuries differed according to type; denuded areas (90%: 103/115) were predominantly located in the proximal part, erosions throughout the small intestine and all ulcers in the distal part. The location of ulcers and denuded areas differed statistically (P < 0.0001).

CONCLUSIONS

The impact of short-term NSAID medication on the small intestine differed according to intestinal site, with most denuded areas identified in the proximal part and all ulcers in the distal part.

Evaluation of portal hypertensive enteropathy by scoring with capsule endoscopy: is transient elastography of clinical impact?

There is limited data about the mucosal lesions of portal hypertensive enteropathy (PHE) detected by capsule endoscopy, and there is no scoring system to evaluate their severity. Our aim is to create a reliable scoring system for PHE, and to explore the possible usefulness of using transient elastograhy (TE) in that field. We compared the medical records of 31 patients with liver cirrhosis and portal hypertension with 29 control patients. We found that the mucosal lesions compatible with PHE were significantly more common in cirrhotic patients than in control patients (67.7% vs 6.9%, p<0.001). Cirrhotic patients with high TE score (p = 0.018), high Child-Pugh grade, large esophageal varices (EV), portal hypertensive gastropathy, and history of endoscopic variceal injection sclerotherapy or ligation (EIS/EVL) were significantly associated with PHE. Using our scoring system, we found that patients with higher TE score (p = 0.004), high Child-Pugh score (p = 0.011), larger EV (p = 0.006), and prior EIS/EVL (p = 0.006) were significantly associated with higher PHE score. We concluded that using our scoring system might be helpful in grading PHE severity, and TE might be a new non-invasive method for detecting the presence and severity of PHE in cirrhotic patients.

Gastroprotective effect of rutin against indomethacin-induced ulcers in rats

Several reports have indicated that indomethacin-induced gastropathy is mediated through generation of free radicals, neutrophil infiltration and disturbance in nitric oxide production. Rutin is a potent antioxidant flavonoid. Recently, rutin was reported to inhibit neutrophil infiltration and to modulate nitric oxide production in gastric mucosa. Therefore, the aim of this study was to investigate the protective effect of rutin against indomethacin-induced gastric injury. Accordingly, four groups of rats were used. The first three groups were injected orally with vehicle, rutin (200 mg/kg) and indomethacin (48 mg/kg) respectively. The fourth group was injected with rutin 1 hr before indomethacin. Animals were killed after 6 hr of indomethacin administration. Gastric juice acidity and gastric injury were evaluated directly. Moreover, the activities of myeloperoxidase, superoxide dismutase and the contents of reduced glutathione, thiobarbituric acid reactive substance and total nitrite/nitrate (as a marker of nitric oxide production) were determined in mucosal tissues. Indomethacin increased gastric ulcer index, gastric myeloperoxidase activity, gastric acidity and thiobarbituric acid reactive substance contents compared with control. On the other hand, indomethacin decreased glutathione, nitrite/nitrate contents and superoxide dismutase activity. Histopathological examination of the stomachs of indomethacin-treated rats revealed degenerative changes in gastric tissues. Pre-treatment with rutin protected gastric tissues against indomethacin-induced gastropathy as demonstrated from reduction in the ulcer index, attenuation of histopathological changes and amelioration of the altered oxidative stress and biochemical parameters. These results indicate that rutin has a protective effect against indomethacin-induced gastropathy probably through inhibiting neutrophil infiltration, suppression of oxidative stress generation and replenishing nitrite/nitrate levels regardless of gastric acidity.