Impaired gastric ulcer healing in diabetic rats: role of heat shock protein, growth factors, prostaglandins and proinflammatory cytokines

Combined effect of pantoprazole and mesenchymal stem cells on experimentally induced gastric ulcer: implication of oxidative stress, inflammation and apoptosis pathways

Gastric ulcer (GU) is one of the most common diseases of the upper gastrointestinal tract that affects millions of people worldwide. This study aimed to investigate the possible alleviating effect of a combined treatment of pantoprazole (PANTO) and adipose tissue-derived mesenchymal stem cells (ADSCs) in comparison with each treatment alone on the healing process of the experimentally induced GU in rats, and to uncover the involved pathways. Rats were divided into five groups: (1) Control, (2) GU, (3) PANTO, (4) ADSCs and (5) ADSCs + PANTO. Markers of oxidative stress, inflammation and apoptosis were assessed. The current data indicated that PANTO-, ADSCs- and ADSCs + PANTO-treated groups showed significant drop (p < 0.05) in serum advanced oxidation protein products (AOPPs) and advanced glycation end products (AGEPs) along with significant elevation (p < 0.05) in serum TAC versus the untreated GU group. Moreover, the treated groups (PANTO, ADSCs and ADSCs + PANTO) displayed significant down-regulation (p < 0.05) in gastric nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), intercellular adhesion molecule-1 (ICAM-1), matrix metallopeptidase 9 (MMP-9) and caspase-3 along with significant up-regulation (p < 0.05) in vascular endothelial growth factor (VEGF) and peroxisome proliferator-activated receptor gamma (PPARγ) genes expression compared to the untreated GU group. Immunohistochemical examination of gastric tissue for transforming growth factor β1 (TGF-β1), epidermal growth factor (EGF) and proliferating cell nuclear antigen (PCNA) showed moderate to mild and weak immune reactions, respectively in the PANTO-, ADSCs- and ADSCs + PANTO-treated rat. Histopathological investigation of gastric tissue revealed moderate to slight histopathological alterations and almost normal histological features of the epithelial cells, gastric mucosal layer, muscularis mucosa and submucosa in PANTO-, ADSCs- and ADSCs + PANTO-treated rats, respectively. Conclusively, the co-treatment with ADSCs and PANTO evidenced sententious physiological protection against GU by suppressing oxidative stress, inhibiting inflammation and reducing apoptosis with consequent acceleration of gastric tissue healing process.

Gastroprotective evaluation of Medicago sativa L. (Fabaceae) on diabetic rats

Traditional uses for the plant Medicago sativa (M. sativa) (Alfalfa) (Family: Fabaceae) include liver protection, antioxidant activity, and the treatment of bleeding and digestive issues. This study aims to assess the effect of ethanol extract of M. sativa (EEMS) on experimental-induced ulcers in diabetic rats. By pylorus ligation and ethanol administration, gastric ulcers were induced in diabetic rats. Five groups each consisting of six rats in each model were used. All other groups except Group I were made diabetic by giving rats alloxan (140 mg/kg i.p.). Vehicles were given to Group I (normal control) and Group II (diabetes control) rats. Group III (positive control) received ranitidine 50 mg/kg, and Group IV and V received EEMS at doses of 100 and 400 mg/kg, respectively. In the pylorus ligation and ethanol-induced stomach ulcer model of rats, the findings demonstrated that EEMS (100 mg/kg) showed a decreased ulcer index of 2.01 ± 0.41 and was found statistically significant against the diabetes control group (p < 0.001) as well as, an ulcer index of 0.68 ± 0.22 by EEMS (400 mg/kg) with a significant reduction in the ulcer index (p < 0.001). EEMS (100 and 400 mg/kg) reduce free acidity by 13.16 ± 0.65 mEq/L and 9.83 ± 0.30 mEq/L, respectively. EEMS also showed a protective impact on the liver and kidneys of diabetic rats. Antihyperglycemic action was also discovered in diabetic animals. The findings of the current investigation demonstrated that ethanolic extract of M. sativa possesses anti-ulcer activity in diabetic rats. Ethanolic extract of M. sativa may be a treatment option for stomach ulcers that also have diabetes.

Evidence for the Involvement of Cytokines Modulation and Prokinetic Properties in Gastric Ulcer Healing Effects of Helicteres sacarolha A. St.-Hil. A. Juss

Preparations of Helicteres sacarolha (Malvaceae) leaves and roots are used in the form of decoction, infusion or maceration, to treat gastrointestinal disturbances, among others. Studies supporting some of its ethnomedicinal uses are still incipient. The present study aimed to investigate it potential effect on chronic ulcer, ulcerative colitis and possible prokinetic activities as part of its mechanism of action. The powdered leaves of Helicteres sacarolha (HEHs) was prepared by maceration in 70 % hydroethanolic solution. Its qualitative phytochemical constituents were investigated by direct flow injection analysis coupled to atmospheric pressure chemical ionization ion trap tandem mass spectrometry (FIA-APCI-IT-MSⁿ ). The gastric ulcer healing effect was evaluated in acetic acid induced chronic ulcer in mice and the lesions were evaluated, including analysis of blood plasma cytokine levels. The prokinetic properties (gastric emptying and intestinal transit) were carried out in mice. Potential anti-ulcerative colitis activity was evaluated in rats using 2,4,6-trinitrobenzenesulfonic acid (5 % TNBS) -induced colitis. All animal experiments were carried out at the doses of 20, 50 and 250 mg/kg (p.o.). Eight compounds were putatively identified, specifically lariciresinol, and its derivatives, kaempferol derivatives and Tricin-O-Glc. The extract promoted increased gastric ulcer healing at all doses tested. Modulation of the cytokines involved inhibition of some key pro-inflammatory cytokines with maximum effect on IL-1β (70 %, 50 mg/kg, p<0.05), TNF-α (79 %, 20 mg/kg, p<0.01), and in the anti-inflammatory cytokines, namely IL-10 (57 %, 50 mg/kg, p<0.05) and IL-17 (79 %, only at 50 mg/kg, p<0.05). Histological findings demonstrated a mitigated inflammatory activity, and tissues undergoing regeneration. HEHs treatment caused delayed gastric emptying, and increased intestinal transit, but had no effect in the experimentally induced ulcerative colitis. We report for the first time putatively the presence of Lariciresinol and tricin derivatives from the hydroethanolic leaves extract of H. sacarolha. Its possible mechanism of actions of gastric ulcer healing involves cytokines modulation, mitigation of inflammatory response and tissue regeneration and provoked opposing effect in the gastrointestinal system. The present study demonstrates the therapeutic potential of H. sacarolha leaves used in Brazilian ethnomedicine in the treatment of chronic gastric ulcer.

Strongly increased risk of gastric and duodenal ulcers among new users of low-dose aspirin: results from two large cohorts with new-user design

BACKGROUND

Low-dose aspirin is a risk factor for peptic ulcer disease but previous, population-based cohort studies may have underestimated the low-dose aspirin risk because they did not use a new-user design. Gastrointestinal bleeding occurs more frequently early after initiation of low-dose aspirin therapy than in later years.

AIM

To assess the associations of low-dose aspirin with gastric and duodenal ulcer incidence in prevalent- and new-user design.

METHODS

Multivariate Cox regression models in the German ESTHER study (N = 7737) and the UK Biobank (N = 213,598) with more than 10 years of follow-up.

RESULTS

In the prevalent-user design, there was no significant association between low-dose aspirin and gastric ulcer observed in both cohorts. Furthermore, low-dose aspirin was weakly, statistically significantly associated with prevalent duodenal ulcer in the UK Biobank (hazard ratio [95% confidence interval]: 1.27 [1.07-1.51]) but not in the ESTHER study (1.33 [0.54-3.29]). When restricting the exposure to only new users, the hazard ratios for incident gastric and duodenal ulcer disease were 1.82 [1.58-2.11] and 1.66 [1.36-2.04] in the UK Biobank, respectively, and 2.83 [1.40-5.71] and 3.89 [1.46-10.42] in the ESTHER study, respectively.

CONCLUSIONS

This study shows that low-dose aspirin is an independent risk factor for both gastric and duodenal ulcers. The associations were not significant or weak in the prevalent-user design and strong and statistically significant in the new-user design in both cohorts. Thus, it is important to weigh risks against benefits when low-dose aspirin treatment shall be initiated and to monitor adverse gastrointestinal symptoms after the start of low-dose aspirin therapy.

Association of Incidence of Acid-related Upper Gastrointestinal Disorders With Glycated Hemoglobin Level

CONTEXT

Previous cross-sectional studies show diabetes and higher levels of plasma hemoglobin A1c (HbA1c) are associated with a higher prevalence of gastrointestinal (GI) complications. However, whether the glycemic status is associated with incident acid-related upper GI disorders remains unclear.

OBJECTIVE

We aimed to determine the effect of hyperglycemia per se, in terms of HbA1c, on the incidence of acid-related disorders.

METHODS

We analyzed consecutive subjects who had undergone repeated upper endoscopies as part of the health examinations at the National Taiwan University Hospital from 2005 to 2011. Acid-related endoscopic abnormalities were defined as erosive esophagitis (EE), Barrett's esophagus (BE), and peptic ulcer disease (PUD), which included gastric ulcers (GUs) and duodenal ulcers (DUs). All subjects were categorized by 3 tertiles of HbA1c levels. We analyzed the occurrence of respective acid-related disorders during the follow-up period.

RESULTS

A total of 11 391 participants (mean HbA1c level 5.6 ± 0.7%) were enrolled in this longitudinal study. During the 38 426.3 person-years of follow-up (mean duration 3.37 ± 1.59 years), the incidence of EE, BE, GU, DU, PUD, and any acid-related disorders were 22.1%, 0.5%, 4.5%, 8.6%, 12.3%, and 30.3%, respectively. The higher HbA1c level was associated with higher risk of disease incidents, except BE, during the follow-up (all log-rank P < .001). In the Cox regression analyses with confounding factors fully adjusted, the hazard ratios for EE, GU, DU, PUD, and acid-related disorders were 1.174, 1.339, 1.24, 1.24, and 1.186, respectively, for the third tertile of HbA1c (all P < .05).

CONCLUSION

Higher HbA1c level was associated with a higher risk of acid-related upper GI endoscopic abnormalities. Efforts toward better glycemic control may help to prevent the development of late GI complications.

The effect of metformin on indomethacin-induced gastric ulcer: Involvement of nitric oxide/Rho kinase pathway

Gastric ulcer is a very common disease that represent an economic burden. Non-steroidal anti-inflammatory drugs induce ulcer in old patients and in patients with comorbidities. Indomethacin is widely used to induce gastric ulcer in animal models. Diabetic patients are highly susceptible to develop gastric ulcer. Metformin, the first line medication for the treatment of type II diabetes melilites that have many off label uses in non-diabetic patients, has been recently reported to have anti-inflammatory activities. Therefore, this research was conducted to assess the possible healing effects of metformin on gastric ulcers induced by indomethacin in rats. Indomethacin (48 mg/kg) single dose increased stomach acidity, ulcer index and induced histopathological changes. Indomethacin also decreased mucin levels and increased the activity of tumor necrosis factor-α (TNF-α), nuclear factor kappa-B (NF-κB), Rho-associated protein kinas-1 (ROCK-1) and decreased the levels of the protective nitric oxide (NO). After the induction of ulcer, rats were treated by omeprazole (30 mg/kg) or metformin (50, 100 or 200 mg/kg). Omeprazole and metformin were found to decrease stomach acidity and ulcer index, restored the histological features and increased mucin levels. Both also decreased the levels of NF-κB, TNF-α, ROCK-1 and increased NO. Metformin exerted ulcer healing effects comparable to that of omeprazole. This can be attributed, at least partly, to its anti-inflammatory activity and increasing NO levels.

Increased Risk of Clopidogrel-Induced Gastric Mucosal Erosion in Elderly Chinese Men Harboring the ABCB1 3435T Allele

Background

It is uncertain whether long-term use of clopidogrel alone can cause gastric mucosal injury. This study aimed to evaluate the relationship between ABCB1 C3435T polymorphisms, which could affect the intestinal absorption of clopidogrel, and gastric mucosal erosion in elderly Chinese men who used clopidogrel alone.

Methods

We selected 298 male patients (aged between 68.2 and 89.5 years, average age 78); 201 of them constituted the control group, and 97 constituted the case group. Patients taking clopidogrel alone who had undergone endoscopic screening for gastric erosion were analyzed for ABCB1 C3435T polymorphisms by a TaqMan assay.

Results

The proportion of people carrying the ABCB1 3435T allele (n = 63, 64.9% vs n = 97, 48.3%, p = 0.007) was significantly higher in the case group than in the control group. After adjustments for significant factors were made, ABCB1 3435T allele carrier (OR 2.14, 95% CI 1.43–3.84, p <0.01) was found to be associated with gastric mucosal erosion in people who used clopidogrel alone.

Conclusion

Carrying the ABCB1 3435T allele may be a useful genetic predictor for clopidogrel-induced gastric mucosal erosion in elderly Chinese men.

(-)-Myrtenol accelerates healing of acetic acid-induced gastric ulcers in rats and in human gastric adenocarcinoma cells

The gastroprotective property of (-)-myrtenol, a monoterpenoid, has been demonstrated previously against acute gastric ulceration induced by ethanol. However, the healing property of (-)-myrtenol in a chronic gastric ulcer model remains to be verified. This study evaluated its healing efficacy and the mechanism involved using the rat model of chronic gastric ulcer induced by serosal injection of 80% acetic acid in vivo, and human gastric adenocarcinoma cells (AGS) in vitro. The results showed that compared to vehicle-treated ulcer controls, oral administration of (-)-myrtenol (50 and 100 mg/kg/day) for 7 days promoted ulcer healing, as indicated by significant decreases in ulcer area and volume. The macroscopic and microscopic findings confirmed the healing potential of (-)-myrtenol. The ulcer healing activity was also associated with significant increases in gastric mucin content, collagen deposition, number of cells with positive marking for proliferating cell nuclear antigen (PCNA), and by changes in the expression of the inflammatory parameters tumor necrosis factor (TNF)-α, interleukin (IL)-1β and cyclooxygenase (COX)-2, as well as a decrease of metalloproteinases (MMP-9 and MMP-2) activity. Furthermore, in vitro assays using the AGS cultures revealed that (-)-myrtenol favors wound healing activity via stimulation of cell proliferation and migration without altering the cell viability. Taken together, these findings indicate that (-)-myrtenol has gastro-cytoprotective and ulcer healing properties that can be further explored to develop a new therapeutic agent from a natural source for the treatment of gastric ulcer.

Exendin-4, a glucagon-like peptide-1 analogue accelerates healing of chronic gastric ulcer in diabetic rats

Background

Diabetes mellitus is an independent risk factor for impaired healing of peptic ulcers, and there are currently no supplementary therapeutics other than the standard antipeptic medicine to improve the ulcer healing in diabetes. This study examined the potential pleiotropic effect of a glucagon-like peptide (Glp)-1 analogue exendin (Ex)-4 on the regeneration of gastric ulcer in streptozotocin-induced diabetic rats.

Methods and results

Chronic ulcer was created in rat stomach by submucosal injection of acetic acid and peri-ulcer tissues were analyzed 7 days after operation. Ulcer wound healing was impaired in diabetic rats with suppressed tissue expression of eNOS and enhanced levels of pro-inflammatory reactions. Treatment with intraperitoneal injection of Ex4 (0.5 μg/kg/d) significantly reduced the area of gastric ulcer without changing blood glucose level. Ex-4 restored the expression of pro-angiogenic factors, and attenuated the generation of regional inflammation and superoxide anions. The improvement of ulcer healing was associated with increased expression of MMP-2 and formation of granulation tissue in the peri-ulcer area.

Conclusion

Administration of Ex4 may induce pro-angiogenic, anti-inflammatory and anti-oxidative reactions in the peri-ulcer tissue of diabetic rats that eventually enhances tissue granulation and closure of ulcerative wounds. Our results support the potential clinical application of Glp-1 analogues as supplementary hypoglycemic agents in the antipeptic ulcer medication in diabetes.

Effects of alcohol consumption, cigarette smoking, and betel quid chewing on upper digestive diseases: a large cross-sectional study and meta-analysis

Cigarette smoking is a well-known risk factor of upper digestive diseases. Findings on alcohol's effect on these diseases are inconsistent and with the exception of its association with esophageal cancer, little is known about betel quid chewing. This study investigated the association between use of these three substances and upper digestive diseases. We collected data from 9,275 patients receiving upper endoscopies between April 2008 and December 2013. Polynomial regressions were used to analyze the association between risk factors and diseases of the esophagus, stomach and duodenum. Meta-analysis for use of these substances and esophageal diseases was also performed. Participants who simultaneously consumed cigarettes, alcohol and betel quid had a 17.28-fold risk of esophageal cancer (95% CI = 7.59-39.33), 2.99-fold risk of Barrette's esophagus (95% CI = 2.40-4.39), 1.60-fold risk of grade A-B erosive esophagitis (95% CI = 1.29-2.00), 2.00-fold risk of gastric ulcer (95% CI = 1.52-2.63), 2.12-fold risk of duodenitis (95% CI = 1.55-2.89) and 1.29-fold risk of duodenal ulcer (95% CI = 1.01-1.65). Concurrent consumption of more substances was associated with significantly higher risk of developing these diseases. Meta-analysis also revealed use of the three substances came with a high risk of esophageal diseases. In conclusions, cigarette smoking, alcohol drinking and betel quid chewing were associated with upper digestive tract diseases.

Comparison between tocotrienol and omeprazole on gastric growth factors in stress-exposed rats

AIM

To investigate and compare the effects of tocotrienol and omeprazole on gastric growth factors in rats exposed to water-immersion restraint stress (WIRS).

METHODS

Twenty-eight male Wistar rats were randomly assigned to four groups of seven rats. The two control groups were administered vitamin-free palm oil (vehicle) and the two treatment groups were given omeprazole (20 mg/kg) or tocotrienol (60 mg/kg) by oral gavage. After 28 d of treatment, rats from one control group and both treated groups were subjected to WIRS one time for 3.5 h. Gastric lesions were measured and gastric tissues were obtained to measure vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and transforming growth factor-alpha (TGF-α) mRNA expression.

RESULTS

Rats exposed to WIRS for 3.5 h demonstrated the presence of considerable ulcers in the form of gastric erosion. The lesion index in the stressed control (S) group was increased (P < 0.001) compared to the tocotrienol treated and omeprazole treated groups. Stress led to a decrease in gastric VEGF (P < 0.001), bFGF (P < 0.001) and TGF-α (P < 0.001) mRNA levels and caused an increase in EGF mRNA (P < 0.001) that was statistically significant compared to the non-stressed control group. Although both treatment agents exerted similar ulcer reducing ability, only treatment with tocotrienol led to increased expression of VEGF (P = 0.008), bFGF (P = 0.001) and TGF-α (P = 0.002) mRNA.

CONCLUSION

Tocotrienol provides gastroprotective effects in WIRS-induced ulcers. Compared to omeprazole, tocotrienol exerts a similar protective effect, albeit through multiple mechanisms of protection, particularly through up-regulation of growth factors that assist in repair of gastric tissue injuries.

Ulcer healing potential of ethanolic extract of Caralluma attenuata on experimental diabetic rats

Introduction:

Available data indicated that diabetes mellitus (DM) increases the vulnerability of the gastric ulcers and the need of the hour is to develop effective agents to treat ulcer with diabetes for better patient compliance and cost effectiveness. The ulcer-healing properties of ethanolic extract of Caralluma attenuata (CAEt) against both chemically- and physically induced gastric ulcers in experimental rats are recently studied.

Aim:

To assess the ulcer healing potential of Ethanolic Extract of Caralluma attenuata on Experimental Diabetic Rats.

Material and Methods:

The current study aimed to evaluate ulcer healing properties of CAEt on the aspirin induced gastric ulcer in rats with streptozotocin induced DM. The hypothesis is based on the fact that DM results in compromising the mucosal defensive factors associated with delay in gastric ulcer healing, and if these changes can be corrected by using agents known for their antidiabetic and antiulcer properties. Experimental albino rats were divided into six groups. Except for Group I, other groups contained streptozotocin-induced diabetic rats. Group I (normal control) and Group II (diabetic control) were administered vehicle, Groups III and IV (diabetic experimental) were administered CAEt in dose of 100 mg/kg and 250 mg/kg, respectively, and Groups V and VI (positive controls) were respectively administered oral standard drugs omeprazole, 20 mg/kg, and tolbutamide 10 mg/kg.

Result:

The results confirmed that the CAEt significantly decreases the ulcer index (P < 0.05) in the aspirin-induced gastric ulcers and also significantly exhibit antioxidant and glucose lowering activity in the diabetic ulcer rats. The study showed that C. attenuata has the potential to be used as an antiulcer agent in experimental diabetic rats.

Type 2 Diabetes Mellitus Is Associated with More Serious Small Intestinal Mucosal Injuries

BACKGROUND

Clinical and experimental research has revealed that diabetes mellitus (DM) is characterized by intestinal hypomotility, gut microbial dysbiosis, increased gut permeability, microcirculation disorders, circulatory changes, and dysfunction of intestinal stem cells, which may be linked to inflammation of intestinal mucosa. However, the relationship between type 2 DM (T2DM) and macroscopic small intestinal mucosal injuries is still unclear. Therefore, we retrospectively studied capsule endoscopy data to determine the relationship between T2DM and small intestinal mucosal injuries.

MATERIALS AND METHODS

We compared the records of 38 T2DM patients with those of 152 non-DM patients for small intestinal mucosal injuries. Different types of mucosal injuries and Lewis scores were compared between T2DM and non-DM patients. The relationships between patients with or without different types of diabetic complications and the Lewis score was assessed. Moreover, the relationships between insulin resistance and Lewis score, between HbA1c and Lewis score, were also both assessed.

RESULTS

The prevalence of a villous edema in subjects with T2DM was significantly higher than in those without DM (P < 0.001), but incidence of ulcers was not different (P = 1.000). With T2DM, the Lewis score was also significantly higher (P = 0.002). In addition, subjects with diabetic nephropathy showed significantly higher Lewis scores than patients without diabetic nephropathy (P = 0.033). In Pearson's correlation tests, the homeostasis model assessment of insulin resistance (HOMA-IR) value was correlated positively with the Lewis score (γ = 0.175, P = 0.015), but no statistical correlation was found between HbA1c level and Lewis score (γ = 0.039, P = 0.697).

CONCLUSIONS

Subjects with T2DM, especially those with diabetic nephropathy, have higher Lewis scores and more serious small intestinal mucosal lesions.

Risk factors of delayed ulcer healing after gastric endoscopic submucosal dissection

BACKGROUND

Although post-endoscopic submucosal dissection (ESD) iatrogenic ulcer is known to heal faster than peptic ulcer, some iatrogenic ulcers show delayed healing. The aim of this study was to clarify risk factors of delayed ulcer healing after gastric ESD.

METHODS

We retrospectively reviewed medical records of all patients who had ESD for gastric neoplasms (866 adenomas and 814 early gastric cancers) between January 2005 and February 2011.

RESULTS

Of 1680 subjects, 95 had delayed ulcer healing in 3-month follow-up. Multivariate analysis showed that diabetes (OR 1.743; 95% CI 1.017-2.989, p = 0.043), coagulation abnormality (OR 3.195; 95% CI 1.535-6.650, p = 0.002), specimen size greater than 4 cm (OR 2.999; 95% CI 1.603-5.611, p = 0.001), and electrocoagulation (OR 7.149; 95% CI 1.738-29.411, p = 0.006) were revealed to be independent risk factors of delayed ulcer healing. Meanwhile, persistent Helicobacter pylori infection was not related to the delayed ulcer healing.

CONCLUSIONS

Large iatrogenic ulcer by ESD with massive hemostasis, especially in patients with diabetes mellitus or coagulation abnormalities, tends to take more than 3 months to heal. For such cases, initial dosage increment of PPI or addition of other anti-ulcer agents after ESD may be beneficial.

Healing effects of Musa sapientum var. paradisiaca in diabetic rats with co-occurring gastric ulcer: cytokines and growth factor by PCR amplification

Background

The present study evaluates the effects of extract of Musa sapientum fruit (MSE) on ulcer index, blood glucose level and gastric mucosal cytokines, TNF-α and IL-1β and growth factor, TGF-α (affected in diabetes and chronic ulcer) in acetic acid (AA)-induced gastric ulcer (GU) in diabetic (DR) rat.

Methods

MSE (100 mg/kg, oral), omeprazole (OMZ, 2.0 mg/kg, oral), insulin (INS, 4 U/kg, sc) or pentoxyphylline (PTX, 10 mg/kg, oral) were given once daily for 10 days in 14 days post-streptozotocin (60 mg/kg, intraperitoneal)-induced diabetic rats while, the normal/diabetic rats received CMC for the same period after induction of GU with AA. Ulcer index was calculated based upon the product of length and width (mm²/rat) of ulcers while, TNF-α, IL-1β and TGF-α were estimated in the gastric mucosal homogenate from the intact/ulcer region. Phytochemical screening and HPTLC analysis of MSE was done following standard procedures.

Results

An increase in ulcer index, TNF-α and IL-1β were observed in normal (NR)-AA rat compared to NR-normal saline rat, which were further increased in DR-AA rat while, treatments of DR-AA rat with MSE, OMZ, INS and PTX reversed them, more so with MSE and PTX. Significant increase in TGF-α was found in NR-AA rat which did not increase further in DR-AA rat. MSE and PTX tended to increase while, OMZ and INS showed little or no effect on TGF-α in AA-DR rat. Phytochemical screening of MSE showed the presence of saponins, flavonoids, glycosides, steroids and alkaloids and HPTLC analysis indicated the presence of eight active compounds.

Conclusion

MSE showed antidiabetic and better ulcer healing effects compared with OMZ (antiulcer) or INS (antidiabetic) in diabetic rat and could be more effective in diabetes with concurrent gastric ulcer.

Diabetes is an independent risk factor for peptic ulcer bleeding: a nationwide population-based cohort study

BACKGROUND AND AIMS

Diabetic patients reportedly have a higher incidence of peptic ulcer disease. The aim of this study was to investigate if type II diabetic patients have higher risk of developing peptic ulcer bleeding (PUB) and to identify possible risk factors of PUB in diabetic patients.

METHODS

Using the National Health Insurance Research Database of Taiwan, records of 5699 type II diabetic patients and 11,226 age- and sex-matched non-diabetic patients in a 1:2 ratio were extracted for comparison from a cohort dataset of 1,000,000 randomly sampled subjects. Log-rank test was used to analyze differences in cumulative hazard of PUB between the two groups. Cox proportional hazard regressions were used to evaluate independent risk factors for PUB in all patients and identified risk factors of PUB in type II diabetic patients.

RESULTS

In a 7-year follow-up period, type II diabetic patients had significantly higher cumulative hazard of PUB than the controls (P < 0.001, log-rank test). By Cox proportional hazard regression analysis, diabetes was independently associated with increased risk of PUB (hazard ratio 1.44, 95% confidence interval 1.11-1.86; P < 0.001) after adjusting for age, sex, comorbidities (e.g. hypertension, coronary heart disease, heart failure, chronic renal disease, cirrhosis, and peptic ulcer disease), and ulcerogenic medication. Age, chronic renal disease, history of peptic ulcer disease, and use of non-steroidal anti-inflammatory drugs were risk factors for PUB in diabetic patients.

CONCLUSIONS

Type II diabetic patients have significantly higher risk of PUB even after adjustments for possible confounding factors like age, sex, underlying comorbidities, and ulcerogenic medication.

Frequency of rebleeding events in obscure gastrointestinal bleeding with negative capsule endoscopy

BACKGROUND AND AIMS

Although capsule endoscopy (CE) is widely used as a first-line diagnostic modality for obscure gastrointestinal bleeding (OGIB), the rebleeding rate after negative CE varies according to different studies. We tried to elucidate the outcomes after negative CE for OGIB and to determine the risk factors associated with rebleeding.

METHODS

We retrospectively reviewed data from 125 patients who had received CE for OGIB.

RESULTS

PillCam SB capsules were used for 92 patients (73.6%) and SB2 capsules for the other 33 (26.4%). The complete visualization of the small bowel was achieved in 93 patients (74.4%). Of the 63 patients (50.4%) who showed negative CE results, 60 patients did not receive any further specific treatment for OGIB, and were analyzed for the rebleeding rate and risk factors for rebleeding. Of the 60 patients, rebleeding episodes were observed in 16 patients (26.7%), and the cumulative rebleeding rates after 6, 12, 24, and 36 months were 12.4%, 14.3%, 28.7%, and 35.9%, respectively. Substantial rebleeding events were observed with similar frequency both after negative CE without subsequent treatment (26.7%) and after positive CE without specific treatment (21.2%) (P = 0.496).

CONCLUSIONS

Considerable rebleeding episodes were observed after negative CE result for OGIB. Further complementary diagnostic work-ups and close follow-up are needed to be considered for patients with OGIB and negative CE results.

Protective effect of Luffa acutangula extracts on gastric ulceration in NIDDM rats: role of gastric mucosal glycoproteins and antioxidants

OBJECTIVE

To study the comparative gastroprotective effect of Luffa acutangula methanolic extract (LAM) and aqueous extract (LAW) on type II diabetes rats.

METHODS

Streptozotocin (65 mg/kg, i.p.) along with nicotinamide (120 mg/kg, i.p.) was used to induce non insulin dependent diabetes mellitus (NIDDM) in rats. A daily oral dose of aspirin (200 mg/kg, i.p.) was administered for initial seven days to induce gastric ulcerations in the diabetic rats. LAM and LAW were administered orally in the doses of 100, 200 and 400 mg/kg once daily for 21 days. Glibenclamide and ranitidine were used as standards for comparing the antidiabetic and antiulcer effect respectively.

RESULTS

LAM significantly (P<0.01) increased mucosal glycoprotein and antioxidant enzyme level in gastric mucosa of diabetic rats than LAW (P <0.05). LAM was efficient in reversing the delayed healing of gastric ulcer in diabetic rats close to the normal level. LAM exhibited better ulcer healing effect than glibenclamide and LAW, because of its both antihyperglycemic and mucosal defensive actions.

CONCLUSIONS

Thus, LAM is proved to be a better alternative for treating gastric ulcers co-occurring with diabetes.

The influence of diabetes mellitus on short-term outcomes of patients with bleeding peptic ulcers

PURPOSE

Little information is available on the influence of diabetes mellitus on the short-term clinical outcomes of patients with bleeding peptic ulcers. The aim of this study is to investigate whether diabetes mellitus influences the short-term clinical outcomes of patients with bleeding peptic ulcers using a Japanese national administrative database.

MATERIALS AND METHODS

A total of 4863 patients treated by endoscopic hemostasis on admission for bleeding peptic ulcers were referred to 586 participating hospitals in Japan. We collected their data to compare the risk-adjusted length of stay (LOS) and in-hospital mortality of patients with and without diabetes mellitus within 30 days. Patients were divided into two groups: patients with diabetes mellitus (n=434) and patients without diabetes mellitus (n=4429).

RESULTS

Mean LOS in patients with diabetes mellitus was significantly longer than those without diabetes mellitus (15.8 days vs. 12.5 days, p<0.001). Also, higher in-hospital mortality within 30 days was observed in patients with diabetes mellitus compared with those without diabetes mellitus (2.7% vs. 1.1%, p=0.004). Multiple linear regression analysis revealed that diabetes mellitus was significantly associated with an increase in risk-adjusted LOS. The standardized coefficient was 0.036 days (p=0.01). Furthermore, the analysis revealed that diabetes mellitus significantly increased the risk of in-hospital mortality within 30 days (odds ratio=2.285, 95% CI=1.161-4.497, p=0.017).

CONCLUSION

This study demonstrated that presence of diabetes mellitus significantly influences the short-term clinical outcomes of patients with bleeding peptic ulcers.

Honey: a novel antioxidant

The global prevalence of chronic diseases such as diabetes mellitus, hypertension, atherosclerosis, cancer and Alzheimer's disease is on the rise. These diseases, which constitute the major causes of death globally, are associated with oxidative stress. Oxidative stress is defined as an "imbalance between oxidants and antioxidants in favor of the oxidants, potentially leading to damage". Individuals with chronic diseases are more susceptible to oxidative stress and damage because they have elevated levels of oxidants and/or reduced antioxidants. This, therefore, necessitates supplementation with antioxidants so as to delay, prevent or remove oxidative damage. Honey is a natural substance with many medicinal effects such as antibacterial, hepatoprotective, hypoglycemic, reproductive, antihypertensive and antioxidant effects. This review presents findings that indicate honey may ameliorate oxidative stress in the gastrointestinal tract (GIT), liver, pancreas, kidney, reproductive organs and plasma/serum. Besides, the review highlights data that demonstrate the synergistic antioxidant effect of honey and antidiabetic drugs in the pancreas, kidney and serum of diabetic rats. These data suggest that honey, administered alone or in combination with conventional therapy, might be a novel antioxidant in the management of chronic diseases commonly associated with oxidative stress. In view of the fact that the majority of these data emanate from animal studies, there is an urgent need to investigate this antioxidant effect of honey in human subjects with chronic or degenerative diseases.

Role of activation of 5'-adenosine monophosphate-activated protein kinase in gastric ulcer healing in diabetic rats

BACKGROUND

The potential utility of 5'-adenosine monophosphate-activated protein kinase (AMPK)-activating agents, such as metformin, in inducing angiogenesis, could be a promising approach to promote healing of gastric ulcers complicated by diabetes mellitus. The aim of the present study was to assess the effect of a drug that activates AMPK, namely metformin, in gastric ulcer healing in streptozotocin-induced diabetic rats.

METHODS

Forty male Wistar albino rats were made diabetic by intraperitoneal (i.p.) streptozotocin injection and 10 rats were injected i.p. by a single dose of physiological saline. Six weeks following streptozotocin or saline injection, gastric ulcers were induced by serosal application of acetic acid. Three days after acetic acid application, rats were divided into group 1 (nondiabetic control), group 2 (streptozotocin-injected rats), groups 3-5 (streptozotocin-injected rats treated with metformin or metformin and an inhibitor of AMPK, namely compound C or pioglitazone) for 7 days following acetic acid application.

RESULTS

Administration of metformin, but not pioglitazone, resulted in a significant decrease in the gastric ulcer area, a significant increase in epithelial regeneration assessed histologically, a significant increase in the number of microvessels in the ulcer margin, a significant increase in gastric vascular endothelial growth factor concentration and gastric von Willebrand factor as well as a significant increase in gastric phospho-AMPK. Compound C, an inhibitor of AMPK, blocked metformin-induced changes in assessed parameters suggesting that the effect of metformin was mediated mainly through activation of AMPK.

CONCLUSION

Our results suggest the feasibility of a novel treatment strategy, namely drugs activating AMPK, for patients in whom impairment of ulcer healing constitutes a secondary complication of diabetes mellitus.

Upregulation of collagenase-1 and -3 in indomethacin-induced gastric ulcer in diabetic rats: role of melatonin

Collagenases are key proteases involved in inflammation and injury. We addressed whether collagenases have an association with the susceptibility of gastric injury under diabetes as well as the effect of melatonin on collagenases in ulcerated gastric tissues. Diabetes was induced in rats by a single dose of streptozotocin (STZ) followed by gastric ulceration using indomethacin, and melatonin's action was studied by its application prior to indomethacin exposure. Ulcer indices and damage were elevated significantly in gastric tissues of diabetic compared with nondiabetic rats. Melatonin reversed the effect of indomethacin during protection of gastric ulcers in diabetic rats. Matrix metalloproteinase (MMP)-13 (i.e., collagenase-3) was upregulated in diabetic gastric mucosa and enhanced further upon ulceration while melatonin ameliorated their activity. In addition, gastric tissues showed enhanced expression of both MMP-1 (i.e., collagenases-1) and -13 significantly in diabetic rats compared with nondiabetic animals and more so during ulceration while tissue inhibitors of metalloproteinase-1 (TIMP-1) showed an opposite trend. MMP-2 activities exhibited a ∼50% downregulation during gastric ulceration which were rescued by melatonin. Moreover, increased expression of both MMP-1 and -13 was mediated by activator protein-1 activation via extracellular signal-regulated kinase 1/2 which were parallel to upregulation of tumor necrosis factor-α, interleukin-1β, and heat shock protein-70 during ulceration. Melatonin arrested collagenase expression by downregulation of these signaling molecules thereby halting the progression of the disease. We conclude that diabetic gastric tissues are susceptible to ulceration and associated with MMP-1 and -13 upregulation in indomethacin-induced injury. Additionally, melatonin protects the gastric damage under diabetes via regulation of both MMP-1 and -13.

Accelerated Ulcer Healing and Resistance to Ulcer Recurrence with Gastroprotectants in Rat Model of Acetic Acid-induced Gastric Ulcer

Quality of ulcer healing (QOUH) is defined as ideal ulcer healing featuring with the fine granular ulcer scar, high functional restoration and the resistance to recurrence. This study was designed to compare the rates of QOUH achievement in rat gastric ulcer model between acid suppressant treated group and gastroprotectant treated group accompanied with elucidations of molecular mechanisms. Serosal injection of acetic acids for generating gastric ulcer and intraperitoneal (ip) injection of recombinant interleukin 1-beta (IL-1β) for recurring healed ulcer was done in SD rats. The 72 rats were divided into three groups according to treatment as follows; Group I, no further treatment, Group II, 8 weeks treatment of omeprazole, and Group III, 8 weeks of gastroprotectant treatment. IL-1β was administered for ulcer recurrence after 28 weeks of acetic acid injection. At four weeks after gastric ulcerogenesis, 58.3% (7/12) of active gastric ulcer were converted to healing stage in Group III, but 16.7% (2/12) in Group II and none in Group I, for which significant levels of epidermal growth factor, mucin, and pS2/trefoil peptide1 were contributive to these accelerated healings of Group III. ip injections of rIL-1β (200 µg/kg) at 28 weeks after acetic acid injection led to 100% of ulcer recurrence in Group I and 75.0% in Group II, but only 16.7% of Group III rats showed ulcer recurrence. Significantly attenuated levels of inflammatory cytokines including IL-2, transforming growth factor-alpha (TNF-α), cyclooxygenase-2 (COX-2), nitrotyrosine were responsible for the resistance to ulcer recurrence in Group III. Conclusively, gastroprotectant might be prerequisite in order to achieve ideal QOUH through significant inductions of remodeling.

Gastroprotective and ulcer-healing mechanisms of ellagic acid in experimental rats

Ellagic acid (EA), a plant-derived polyphenol, exhibits antioxidant, anti-inflammatory, and gastroprotective effects. Its gastroprotective mechanisms have not been fully elucidated nor have its effects on chronic ulcer previously been described. Toward these ends, the antiulcer activities of EA were evaluated in acute (ethanol and indomethacin) and chronic (acetic acid) ulcer models in Wistar rats. In this study, oral administration of EA significantly prevented the gastric ulceration caused by ethanol, indomethacin, and acetic acid treatments. Its gastroprotective mechanism in ethanol-induced ulcer were partly due to intensification in the endogenous production of nitric oxide, an antioxidant effect by replenishing depletion of endogenous nonprotein sulfhydryls and attenuation of tumor necrosis factor-α increase, whereas in indomethacin ulcer, it is partly due to a reduction in the plasma level of leukotriene B(4). In acetic acid ulcer, promotion of ulcer-healing effects was partly due to attenuation of the elevated levels of the inflammatory cytokines TNF-α, interferon-γ, and interleukins-4 and -6. These findings suggest that ellagic acid exerts its antiulcer activity by strengthening the defensive factors and attenuating the offensive factors.

Nutritional Composition, Antioxidant Activities, and Antiulcer Potential of Lentinus squarrosulus (Mont.) Mycelia Extract

Water extract of Lentinus squarrosulus mycelia was analysed for nutritional content, antioxidant capacity, and antiulcer ability. The extract contains high protein (57.6 g/100 g) and low total fat (0.5 g/100 g) and is rich in magnesium (0.4 g/100 g), potassium (3.8 g/100 g), vitamins B₁ (1.42 mg/100 g), and B₃ (194.29 mg/100 g) with total phenolic content of 39.16 mg/100 g. The cupric reducing antioxidant capacity and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of the extract were A₄₅₀ of 0.20 ± 0.03 at 0.5 mg/ml and IC₅₀ of 14.29 mg/ml, respectively. Oral feeding of L. squarrosulus extract (250 mg/kg) offered significant gastric mucosal protection of Sprague-Dawley rats compared to cimetidine (50 mg/kg). The ulcer healing rate of ulcerated rats after 24, 48, and 72 hours of treatment was 82%, 90%, and 100%, respectively. The IL-1β level in the serum and the NF-κB level in the tissues indicate that the healing potential was associated with attenuation of proinflammatory cytokines.

Enhancement of gastric ulcer healing and angiogenesis by cochinchina Momordica seed extract in rats

Cochinchina momordica seed is the dried ripe seed of Momordica cochinchinensis, a perennial vine. The antiulcer effect of an extract from cochinchina momordica seeds (SK-MS10) was evaluated in a rat model of acetic acid-induced gastric ulcers. Gastric ulcers were produced by subserosal injection of acetic acid. SK-MS10 (200 mg/kg) or vehicle was administered orally once per day for 14 days after the acetic acid injection. The stomach was removed and the ulcer size measured at day 7 and 14 of the treatment. Expression of vascular endothelial growth factor (VEGF) was assessed by real-time RT-PCR and Western blot analysis. In addition, the microvasculature density (MVD) adjacent to the ulcer margin was examined by immunohistochemistry. The treatment with SK-MS10 for 7 and 14 days significantly accelerated ulcer healing and increased the expression of mRNA (at day 7) as well as VEGF protein (at day 14) compared to the vehicle-treated rats. The MVD for factor VIII was also higher in the SK-MS10 treatment group compared to the vehicle-treated rats; however, these differences were not statistically significant. These results suggest that SK-MS10 treatment accelerates the healing of gastric ulcers via upregulation of VEGF and angiogenesis in an acetic acid rat model.

Antiplatelet therapy, Helicobacter pylori infection and complicated peptic ulcer disease in diabetes: the Fremantle Diabetes Study

AIMS

To assess whether, based on its relationship with complications of peptic ulcer disease (PUD), directed Helicobacter pylori serological screening is justified in diabetic patients prior to commencement of antiplatelet therapy.

METHODS

We analysed data from the longitudinal, community-based Fremantle Diabetes Study (FDS). The present substudy included (i) 1301 patients (91.2% of the total FDS sample; mean age 62.0 +/- 13.3 years, 49.5% male) with available sera from baseline assessment between 1993 and 1996, and (ii) a subset of 40 patients admitted to hospital for complicated PUD (bleeding and/or perforation) between baseline and end of June 2006. All hospital admissions for complicated PUD in the population of Western Australia were identified over the same period. Helicobacter pylori IgG antibodies were measured in all patients at baseline and in the subset at the FDS visit prior to hospital admission.

RESULTS

Helicobacter pylori seropositivity was present in 60.6% of FDS patients at baseline and was independently associated with increasing age and non-Anglo-Celt/non-Asian ethnicity. There were 2.9 (95% confidence interval 2.1, 3.9) first admissions for complicated PUD per 1000 patient-years, an incidence more than seven times that in the local general population. Independent baseline predictors of hospital admission were increasing age, serum urea, non-aspirin anticoagulant therapy, sulphonylurea therapy, peripheral arterial disease and diabetic retinopathy, but not aspirin use, H. pylori seropositivity or their interaction.

CONCLUSIONS

There are diabetes-specific risk factors for complicated PUD, including sulphonylurea use and vascular complications. Knowledge of H. pylori serological status does not predict complicated PUD in diabetes regardless of use of antiplatelet therapy.

Dynamic physiological and molecular changes in gastric ulcer healing achieved by melatonin and its precursor L-tryptophan in rats

Following induction of gastric ulcer in rats by serosal application of acetic acid, local mucosal necrosis ensues accompanied by a reduction in mucosal microcirculation and by almost immediate expression of inducible nitric oxide (NO) synthase (iNOS) and proinflammatory cytokines. Daily application of melatonin (20 mg/kg) or l-tryptophan (100 mg/kg) accelerates ulcer healing by affecting the cyclooxygenase-2 (COX-2)-prostaglandin (PG) system with excessive production of protective PG, especially in later period of ulcer healing. Furthermore, expression of hypoxia inducible factor, vascular-endothelial growth factor, an activation of cNOS-NO system and the stimulation of sensory nerves with the expression and release of calcitonin gene related peptide (CGRP) appear to aid the restoration of mucosal repair and microcirculation in the ulcer bed. The enhanced expression of the melatonin MT(2) receptors (MT(2)-R) combined with overexpression of key enzymes involved in biosynthesis of melatonin such as N-acetyltransferase and hydroxyindole-O-methyltransferase contribute to the acceleration of ulcer healing by this indole. Melatonin-induced acceleration of ulcer healing is also mediated by release of gastrin and ghrelin, the most potent stimulants of gastric mucosal cell proliferation and mucosal repair. These sequential steps in ulcer healing accelerated by melatonin can be interfered with by the blockade of MT(2)R, COX-2/PG and cNOS/NO systems, and by reduction in the inflammatory iNOS/NO system. Thus, melatonin and its precursor l-tryptophan, trigger the cascade of molecular events leading to the functional improvement in ulcer healing.

Diabetes and 30-day mortality from peptic ulcer bleeding and perforation: a Danish population-based cohort study

OBJECTIVE

Diabetes may influence the outcome of complicated peptic ulcer disease, due to angiopathy, blurring of symptoms, and increased risk of sepsis. We examined whether diabetes increased 30-day mortality among Danish patients hospitalized with bleeding or perforated peptic ulcers.

RESEARCH DESIGN AND METHODS

This population-based cohort study took place in the three Danish counties of North Jutland, Viborg, and Aarhus between 1991 and 2003. Patients hospitalized with a first-time diagnosis of peptic ulcer bleeding or perforation were identified using the counties' hospital discharge registries. Data on diabetes, other comorbidities, and use of ulcer-associated drugs were obtained from discharge registries and prescription databases. The Danish Civil Registry System allowed complete follow-up for mortality. The outcome under study was 30-day mortality in diabetic versus nondiabetic patients, adjusted for potential confounders.

RESULTS

We identified 7,232 patients hospitalized for bleeding ulcers, of whom 731 (10.1%) had diabetes. The 30-day mortality among diabetic patients was 16.6 vs. 10.1% for other patients with bleeding ulcers. The adjusted 30-day mortality rate ratio (MRR) for diabetic patients was 1.40 (95% CI 1.15-1.70). We also identified 2,061 patients with perforated ulcers, of whom 140 (6.8%) had diabetes. The 30-day mortality among diabetic patients was 42.9 vs. 24.0% in other patients with perforated ulcers, corresponding to an adjusted 30-day MRR of 1.51 (1.15-1.98).

CONCLUSIONS

Among patients with peptic ulcer bleeding and perforation, diabetes appears to be associated with substantially increased short-term mortality.

Ghrelin-induced gastroprotection against ischemia-reperfusion injury involves an activation of sensory afferent nerves and hyperemia mediated by nitric oxide

Ghrelin has been recently identified as an endogenous ligand for growth hormone secretagogue receptor that regulates growth hormone secretion, increases appetite and contributes to energy homeostasis. Although this peptide is predominantly produced by the fasted stomach, little is known about its influence on the gastric mucosal integrity. The aim of the present study was (1) to investigate the effect of acylated ghrelin on the formation and healing of acute gastric mucosal lesions induced by ischemia-reperfusion and gastric mucosal blood flow in rats; (2) to analyse the effects of the deactivation of afferent sensory nerves with capsaicin and of the inhibition of nitric oxide (NO)-synthase by NG-nitro-l-arginine (l-NNA) on the ghrelin-induced protection; (3) to examine the influence of ghrelin on nuclear factor-kappa B (NF-kappaB) activation and on release of proinflammatory cytokines, such as tumor necrosis factor-alpha, (4) to assess the effect of ghrelin on the mRNA expression of constitutive nitric oxide synthase (cNOS), calcitonin gene related peptide (CGRP) and angiogenesis related proteins such as hypoxia inducible factor-1 alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF), and (5) to determine the effect of ischemia/reperfusion on the gastric mucosa expression of ghrelin in rats without and with administration of exogenous hormone. Wistar rats were exposed to 30 min of ischemia followed by 3 h of reperfusion. Ghrelin was administered in dose of 5, 10 or 20 mug/kg intraperitoneally (i.p.) 30 min prior exposure to ischemia/reperfusion and at 3 h after the end of ischemia, the mean lesion area was measured by planimetry and the changes in gastric blood flow were determined by hydrogen (H2)-gas clearance method. The healing of ischemia/reperfusion induced lesions was evaluated at 24 h or 6 days after the end of standard ischemia/reperfusion. The expression of cNOS, CGRP, HIF-1alpha, VEGF and ghrelin was evaluated by reverse transcription polymerase chain reaction or Western blot. Ghrelin significantly attenuated the ischemia/reperfusion-induced gastric lesions and accelerated the healing of these lesions while significantly raising the gastric blood flow. Deactivation of sensory nerves with capsaicin or inhibition of cNOS by L-NNA significantly attenuated the protective activity of ghrelin and accompanying increase in the GBF. Exogenous ghrelin significantly inhibited the activation of NF-kappaB and plasma TNF-alpha levels. The ghrelin-enhanced acceleration of healing of ischemia/perfusion induced lesions was accompanied by enhanced expression of mRNA for HIF-1alpha and by diminution of the ischemia/reperfusion induced increase in mRNA expression for TNF-alpha. We conclude that ghrelin exerts a potent protective action on the gastric mucosa and accelerates the healing of ischemia/reperfusion-induced lesions and these effects depend upon activation of sensory nerves, hyperemia mediated by NO, increased angiogenesis due to expression of YEGF and anti-inflammatory properties of this peptide.

An overview of acetic acid ulcer models--the history and state of the art of peptic ulcer research

Four types of experimental chronic ulcer models, named acetic acid ulcer models, have been developed to examine the healing process of peptic ulcers, screen anti-ulcer drugs, and better evaluate the adverse effects of various anti-inflammatory drugs on the gastrointestinal mucosa. The model easily and reliably produces round, deep ulcers in the stomach and duodenum, allowing acetic acid ulcer production in mice, rats, Mongolian gerbils, guinea pigs, cats, dogs, miniature pigs, and monkeys. These ulcer models highly resemble human ulcers in terms of both pathological features and healing process. The models have been established over the past 35 years and are now used throughout the world by basic and clinical scientists. One of the characteristic features of acetic acid ulcers in rats is the spontaneous relapse of healed ulcers >100 d after ulceration, an endoscopically confirmed phenomenon. Indomethacin significantly delays the healing of acetic acid ulcers, probably by reducing endogenous prostaglandins and inhibiting angiogenesis in ulcerated tissue. Helicobacter pylori significantly delays healing of acetic acid ulcers and causes relapse of healed ulcers at a high incidence in Mongolian gerbils. Anti-secretory drugs (e.g. omeprazole), prostaglandin analogs, mucosal defense agents (e.g. sucralfate), and various growth factors all significantly enhance healing of acetic acid ulcers. Gene therapy with epidermal growth factor and vascular endothelial growth factor applied to the base of acetic acid ulcers in rats is effective in enhancing ulcer healing. Since an inhibitor of nitric oxide syntase prevents ulcer healing, nitric oxide might be involved in the mechanism underlying ulcer healing. We conclude that acetic acid ulcer models are quite useful for various studies related to peptic ulcers.

[Electrocardiographic findings during colonoscopy]

Impaired diabetic wound healing constitutes a major health problem. The impaired healing is caused by complex factors such as abnormal keratinocyte and fibroblast migration, proliferation, differentiation, and apoptosis, abnormal macrophage polarization, impaired recruitment of mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs), and decreased vascularization. Diabetes-enhanced and prolonged expression of TNF-α also contributes to impaired healing. In this paper, we discuss the abnormal cell responses in diabetic wound healing and the contribution of TNF-α.