Heme oxygenase-1 is protective against nonsteroidal anti-inflammatory drug-induced gastric ulcers

A comprehensive review on phytochemicals as potential therapeutic agents for stress-induced gastric ulcer

Gastric ulcers are the most common chronic gastrointestinal tract disorders, marked by an inflamed break of the mucus membrane covering the alimentary tract. According to recent research, stress-induced ulcers are widespread in our society. A stress ulcer is a mucosal defect that may become complicated due to upper gastrointestinal tract bleeding. The underlying cause of this condition is pH. Physiological stress leads to severe sickness by triggering the excessive secretion of peptic juices or gastric acid. There is a never-ending quest for safe and affordable medication for this disorder. Nature offers many medicinal plants that can be used to treat a wide range of human ailments. Due to their relatively harmless and comparatively free of harmful effects, health-promoting features, pharmacological practices, and affordability to common people to regulate various diseases, medicinal plants, and herbal preparations are gaining a lot of interest in scientific communities these days. Many studies have recently been performed to classify extracts and their constituents that may have a therapeutic effect on peptic ulcers. Therefore, this review aims to address the molecular mechanisms and pharmacological effects of various phytochemicals related to stress-induced gastric ulcers. Combining phytochemical constituents with modern drugs and treatment methods can lead to the development of therapeutic drugs for gastric ulcers. Gastric ulcers and other related diseases may be treated permanently with this approach.

Apigenin attenuates indomethacin-induced gastric ulcer in rats: emphasis on antioxidant, anti-inflammatory, anti-apoptotic, and TGF-β1 enhancing activities

Gastric ulcer disease is associated with significant morbidity and mortality rates. The most two common causes of the ulcer are Helicobacter pylori infection and non-steroidal anti-inflammatory drugs. In the past few decades, a significant decrease in the morbidity and mortality rate has been observed probably due to the discovery of proton pump inhibitors. However, the medications used to treat gastric ulcers impose several nauseous side effects. Therefore, recent studies focus on the use of natural products to treat gastric ulcers. In the current study, gastric ulcer was effectively induced using indomethacin, and the protective effect of apigenin, a potent antioxidant flavonoid, was assessed in comparison to omeprazole. The administration of a single oral indomethacin (50 mg/kg) induced gastric ulcer as manifested by hemorrhagic lesions in the gastric mucosa, increased ulcer index, and histopathological alterations. Indomethacin also increased lipid peroxidation, decreased the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase, increased the immunoreactivity of the inflammatory markers cyclo-oxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α), and nuclear factor-kappa B (NF-κB), increased the transcription of the apoptotic marker, Bax, and decreased that of the antiapoptotic Bcl-2. Indomethacin also decreased the immunoreactivity of transforming growth factor-beta 1 (TGF-β1). On the other hand, pretreatment with apigenin (10 and 20 mg/kg) resulted in a dose-dependent improvement in the macroscopic and microscopic features of the gastric mucosa in a manner comparable to that of omeprazole. The gastroprotective effects of apigenin may be attributed to its anti-inflammatory, anti-antioxidant, and anti-apoptotic activities as well as enhancing the expression of TGF-β1. Further experimental and clinical research is required to confirm activity of apigenin as anti-ulcer agent.

Probiotic bacteria protect against indomethacin-induced gastric ulcers through modulation of oxidative stress, inflammation, and apoptosis

BACKGROUND

Indomethacin is an anti-inflammatory drug that causes ulcers on the gastric mucosa due to its use. Probiotic bacteria are live microorganisms, and it has been stated by various studies that these bacteria have antioxidant and anti-inflammatory effects. In this study, we investigated the possible protective effect of various types of probiotic bacteria (Lactobacillus rhamnosus, Lactobacillus fermentum, and Lactobacillus brevis) against acute gastric mucosal damage caused by indomethacin.

METHODS

Control group - Physiological saline was administered daily for 10 days. Indo group-Physiological saline was administered daily for 10 days. Ranitidine + Indo group 5 mg/kg ranitidine dose was administered daily for 5 days. On day 11, a single dose of 100 mg/kg of indomethacin was given to the same group. Probiotic + Indo group 1 ml/kg of oral probiotic bacteria was administered daily for 10 days. On day 11, a single 100 mg/kg dose of indomethacin was given. After the application, the rats were anesthetized with ketamine xylazine, killed under appropriate conditions, the abdominal cavity was opened and the stomach tissues were removed. The obtained gastric tissues were used in the biochemical and histopathological analyses discussed below. All data were statistically evaluated by one-way ANOVA using SPSS 20.00, followed by Duncan Post hoc test. The data were expressed as mean ± SD. P < 0.05 was considered statistically significant.

RESULTS

As a result, the administration of indomethacin caused gastric damage, stimulating oxidative stress, inflammation, and apoptosis. We found that the use of probiotic bacteria reduces oxidative stress (TOC), increases the activity of antioxidant enzymes (TAC), suppresses inflammation (IL-6 and Tnf-α), and inhibits apoptosis (Bax and Bcl-2) (P < 0.05).

CONCLUSION

Probiotic treatment can mitigate gastric damage and apoptosis caused by indomethacin-induced gastric damage in rats. Probiotic also enhances the restoration of biochemical oxidative enzymes as it has anti-inflammatory, antioxidant, and antiapoptotic properties.

Mechanism of Wuzhuyu decoction on alcohol-induced gastric ulcers using integrated network analysis and metabolomics

Background: Gastric ulcers (GUs) are prevalent digestive disorders worldwide. Wuzhuyu Decoction (WZYT) is a traditional Chinese medicine that has been employed for centuries to alleviate digestive ailments like indigestion and vomiting. This study aims to explore the potential effects and underlying mechanisms of WZYT on alcohol induced gastric ulcer treatment. Methods: We employed macroscopic assessment to evaluate the gastric ulcer index (UI), while the enzyme-linked immunosorbent assay (ELISA) was utilized for detecting biochemical indicators. Pathological tissue analysis involved hematoxylin-eosin (H&E) staining and Periodic Acid-Schiff (PAS) staining to assess gastric tissue damage. Additionally, the integration of network analysis and metabolomics facilitated the prediction of potential targets. Validation was conducted using Western blotting. Results: The research revealed that WZYT treatment significantly reduced the gastric ulcer index (UI) and regulation of alcohol-induced biochemical indicators levels. Additionally, improvements were observed in pathological tissue. Network analysis results indicated that 62 compounds contained in WZYT modulate alcohol-induced gastric ulcers by regulating 183 genes. The serum metabolomics indicated significant changes in the content of 19 metabolites after WZYT treatment. Two pivotal targets, heme oxygenase 1 (HMOX1) and albumin (ALB), are believed to assume a significant role in the treatment of gastric ulcers by the construction of "compounds-target-metabolite" networks. Western blot analysis confirmed that WZYT has the capacity to elevate the expression of HMOX1 and ALB targets. Conclusion: The integration of network analysis and metabolomics provides a scientific basis to propel the clinical use of WZYT for GUs. Our study provides a theoretical basis for the use of Wuzhuyu decoction in the treatment of gastric ulcers.

Role of Heme Oxygenase in Gastrointestinal Epithelial Cells

The gastrointestinal tract is a unique organ containing both vascular and luminal routes lined by epithelial cells forming the mucosa, which play an important role in the entry of nutrients and act as a selective barrier, excluding potentially harmful agents. Mucosal surfaces establish a selective barrier between hostile external environments and the internal milieu. Heme is a major nutritional source of iron and is a pro-oxidant that causes oxidative stress. Heme oxygenases (HOs) catalyze the rate-limiting step in heme degradation, resulting in the formation of iron, carbon monoxide, and biliverdin, which are subsequently converted to bilirubin by biliverdin reductase. In gastrointestinal pathogenesis, HO-1, an inducible isoform of HO, is markedly induced in epithelial cells and plays an important role in protecting mucosal cells. Recent studies have focused on the biological effects of the products of this enzymatic reaction, which have antioxidant, anti-inflammatory, and cytoprotective functions. In this review, the essential roles of HO in the gastrointestinal tract are summarized, focusing on nutrient absorption, protection against cellular stresses, and the maintenance and regulation of tight junction proteins, emphasizing the potential therapeutic implications. The biochemical basis of the potential therapeutic implications of glutamine for HO-1 induction in gastrointestinal injury is also discussed.

Chinese sumac (Rhus chinensis Mill.) fruits alleviate indomethacin-induced gastric ulcer in mice by improving oxidative stress, inflammation and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

According to traditional Chinese medicine and a previous literature, many parts of Chinese sumac (Rhus chinensis Mill.), including fruits, are used as traditional herb to prevent or cure many diseases, such as inflammation, diarrhea, malaria, and other acute or chronic gastrointestinal diseases. However, the effects of the fruits on the prevention of gastric ulcer and the underlying mechanisms have not been reported.

AIM OF THE STUDY

This experiment aimed to investigate the preventive effect of ethanol extract (RM) from Chinese sumac fruits on indomethacin-induced gastric ulcer in mice and the underlying mechanisms.

MATERIALS AND METHODS

A single gavage of indomethacin was used to induce a gastric ulcer model in Kunming male mice. According to the results of histopathological analysis, immunohistochemistry and immunofluorescence analysis, as well as the expression of prostaglandin E-2, antioxidant enzymes and cytokines, the protective effect of RM on indomethacin-induced gastric ulcer was evaluated. The expression levels of several key proteins involved in oxidative stress, inflammation and apoptosis in gastric tissue were detected to illuminate the underlying mechanisms.

RESULTS

RM significantly reduced the ulcer index and pepsin activity, improved the microstructure of gastric mucosa and the prostaglandin E-2 content, restored the levels of glutathione and superoxide dismutase, and decreased the contents of malondialdehyde, advanced oxidation protein products, TNF-α, IL-1 β and IL-6. Further experimental results showed that RM could improve the expression levels of HO-1 and NQO1 by activating the Nrf2 protein pathway to alleviate oxidative stress in gastric tissue. At the same time, RM significantly down-regulated the expressions of p-NF-κB, p-IκBα and iNOS to relieve inflammatory response, and inhibited the cellular apoptosis of gastric tissue by up-regulating Bcl-2 and down-regulating Bax and cleaved Caspase-3.

CONCLUSIONS

The current work clarified that the ethanol extract from Chinese sumac fruits can improve the oxidative stress level, inflammatory response and cell apoptosis in gastric tissue by interfering with the expressions of several key regulatory proteins to prevent indomethacin-induced gastric ulcer in mice. This study may provide some insights and scientific evidence on the application of Chinese sumac fruits as a traditional herb to prevent or alleviate gastric ulcer.

Benzyl isothiocyanates modulate inflammation, oxidative stress, and apoptosis via Nrf2/HO-1 and NF-κB signaling pathways on indomethacin-induced gastric injury in rats

The present study investigated the gastroprotective activity of benzyl isothiocyanates (BITC) on indomethacin (IND)-induced gastric injury in a rat model and explicated the possible involved biochemical, cellular, and molecular mechanisms. The rat model with gastric ulcers was established by a single oral dose of IND (30 mg per kg b.wt). BITC (0.75 and 1.5 mg kg^-1) and esomeprazole (20 mg per kg b.wt) were orally administered for 3 weeks to rats before the induction of gastric injury. Compared with the IND group, BITC could diminish both the macroscopic and microscopic pathological morphology of gastric mucosa. BITC significantly preserved the antioxidants (glutathione GSH, superoxide dismutase SOD), nitric oxide (NO), and prostaglandin E2 (PGE2) contents, while decreasing the gastric mucosal malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), and myeloperoxidase (MPO) contents. Moreover, BITC remarkably upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), hemoxygenase-1 (HO-1), and NAD(P)H : quinone oxidoreductase (NQO1). In addition, BITC activates the expression of heat shock protein 70 (HSP-70) and downregulated the expression of nuclear factor-κB (NF-κB) and caspase-3 to promote gastric mucosal cell survival. To the best of our knowledge, this study is the first published report to implicate the suppression of inflammation, oxidative stress, and Nrf2 signaling pathway as a potential mechanism for the gastroprotective activity of BITC.

Heme Oxygenase-1 in Gastrointestinal Tract Health and Disease

Heme oxygenase 1 (HO-1) is the rate-limiting enzyme of heme oxidative degradation, generating carbon monoxide (CO), free iron, and biliverdin. HO-1, a stress inducible enzyme, is considered as an anti-oxidative and cytoprotective agent. As many studies suggest, HO-1 is highly expressed in the gastrointestinal tract where it is involved in the response to inflammatory processes, which may lead to several diseases such as pancreatitis, diabetes, fatty liver disease, inflammatory bowel disease, and cancer. In this review, we highlight the pivotal role of HO-1 and its downstream effectors in the development of disorders and their beneficial effects on the maintenance of the gastrointestinal tract health. We also examine clinical trials involving the therapeutic targets derived from HO-1 system for the most common diseases of the digestive system.

Gastro-Protective and Anti-Oxidant Potential of Althaea officinalis and Solanum nigrum on Pyloric Ligation/Indomethacin-Induced Ulceration in Rats

Recently, an alternative disease treatment approach is the research of medicaments from traditional medicine. Plants with anti-oxidant capabilities are used as herbal treatments for ulcer diseases. Medicinal/herbal extracts containing phytoconstituents have significant anti-ulcer activities in in vivo experiments on animal models, compared to reference drugs. The current study aims to inspect gastro-protective as well as in vitro and in vivo anti-oxidant potential of Althaea officinalis and Solanum nigrum extracts on pyloric-ligation/indomethacin-induced gastric-ulceration in rats. Rats were divided into six groups: normal control, gastric ulcer control, two standard pretreatment groups receiving omeprazole and misoprostol, and two test pretreatment groups receiving Althaea officinalis and Solanum nigrum. Pretreatments were administrated orally for 14 days. On the 15th day, animals, excluding the normal control group, were exposed to pyloric-ligation followed by indomethacin injection. After four hours, the rat’s stomachs were removed and gastric juice and blood samples were collected. Pyloric-ligation/indomethacin administration caused considerable elevation in ulcer number, ulcer index, acid and pepsin productivity, aggressive factors, and gastric mucosal lipid-peroxide contents. Moreover, reduction in titratable acidity, gastric mucosal nitric-oxide, anti-oxidant contents, and protective factors accompanied gastric-ulceration. Additionally, elevation in pro-inflammatory cytokines content and reduction in cystathionine-β-synthase and heme-oxygenase-1 expression was witnessed. Omeprazole, misoprostol, Althaea officinalis, and Solanum nigrum pretreatments fixed blood and tissue biomarkers, thereby protecting them from pyloric-ligation/indomethacin-induced gastric-ulceration in rats, which is hopeful for clinical examinations.

STW 5 is effective against nonsteroidal anti-inflammatory drugs induced gastro-duodenal lesions in rats

BACKGROUND

Proton pump inhibitors are often used to prevent gastro-intestinal lesions induced by nonsteroidal anti-inflammatory drugs. However, they are not always effective against both gastric and duodenal lesions and their use is not devoid of side effects.

AIM

To explore the mechanisms mediating the clinical efficacy of STW 5 in gastro-duodenal lesions induced by nonsteroidal anti-inflammatory drugs (NSAIDs), exemplified here by diclofenac, in a comparison to omeprazole.

METHODS

Gastro-duodenal lesions were induced in rats by oral administration of diclofenac (5 mg/kg) for 6 successive days. One group was given concurrently STW 5 (5 mL/kg) while another was given omeprazole (20 mg/kg). A day later, animals were sacrificed, stomach and duodenum excised and divided into 2 segments: One for histological examination and one for measuring inflammatory mediators (tumor necrosis factor α, interleukins-1β and 10), oxidative stress enzyme (heme oxygenase-1) and apoptosis regulator (B-cell lymphoma 2).

RESULTS

Diclofenac caused overt histological damage in both tissues, associated with parallel changes in all parameters measured. STW 5 and omeprazole effectively prevented these changes, but STW 5 superseded omeprazole in protecting against histological damage, particularly in the duodenum.

CONCLUSION

The findings support the therapeutic usefulness of STW 5 and its superiority over omeprazole as adjuvant therapy to NSAIDs to protect against their possible gastro-duodenal side effects.

Diacerein protects against glycerol-induced acute kidney injury: Modulating oxidative stress, inflammation, apoptosis and necroptosis

Necroptosis is suggested to have an important role in the pathogenesis of rhabdomyolysis induced acute kidney injury (AKI). In this study, the renoprotective effect of diacerein on glycerol-induced AKI was investigated. Twenty four male albino rats were included in this study and divided into four groups: (group I) saline control group, (group II) glycerol-treated group, (groups III&IV) diacerein + glycerol -treated groups (25 and 50 mg/kg/day) respectively. Renal malondialdehyde (MDA) level in addition to catalase and heme oxygenase (HO) activities were estimated. Comet assay and histopathological changes were evaluated. The levels of pro-apoptotic Bcl-2-associated X (Bax) protein, tumor necrosis factor alpha (TNF-α) and receptor-interacting serine/threonine-protein kinases 3 (RIPK3) were measured by ELISA. RIPK3 and mixed lineage kinase domain-like pseudokinase (MLKL) mRNA expression were assessed by real time PCR. Glycerol treatment caused significant renal histological abnormalities and functional impairment (increased urea and creatinine). Increased levels of renal MDA with concomitant decrease in renal catalase activity and significant DNA damage in comet assay were observed. High expression of RIPK3 and MLKL in the glycerol-treated group with marked elevation of Bax, TNF-α and RIPK3 levels and HO-1 activity were also documented. Diacerein treatment dependently attenuated glycerol induced structural and functional changes in kidney and significantly elicit reduction of renal tissue oxidative damage whereas it decreased renal expression of RIPK3 and MLKL, and decreased Bax, TNF-α and RIPK3 levels and HO-1 activity. CONCLUSION: These results demonstrated that diacerein might have potential application in the amelioration of AKI via its anti-oxidant, anti-inflammatory, anti-apoptotic and anti-necroptotic effects.

Mechanisms underlying gastroprotective effect of paeonol against indomethacin-induced ulcer in rats

Paeonol, a natural phenolic compound, possesses diverse beneficial effects including antioxidant and anti-inflammatory effects. Gastric ulcer is still the most prevalent irritant illness among the gastrointestinal diseases. The present study explored the protective effect of paeonol at two dose levels in indomethacin (IND)-induced gastric ulcer in rats. Forty-eight male Wistar rats were arranged into six groups: control, paeonol-treated, IND-treated, IND/paeonol (low and high doses)-treated, and ranitidine-treated groups. The oxidative status was evaluated by determining malondialdehyde level, superoxide dismutase activity, reduced glutathione content as well as hemoxygenase-1 (HO-1) gene expressions, and the antioxidant protein; NAD(P)H quinone oxidoreductase 1 (NQO1) immunostaining. The pro-inflammatory genes nuclear factor κB (NF-κB) and interleukin 1β (IL-1β) were estimated together with the proapoptotic gene of caspase 3. IND caused multiple gastric ulcers with evident oxidative damage and elevated pro-inflammatory and proapoptotic markers. Paeonol protected significantly, in a dose-dependent manner, the gastric mucosa from ulcerative lesion of IND similar to the reference drug ranitidine. Paeonol pretreatment diminished gastric oxidative stress and restored the gastric antioxidant capacity by elevating gastric gene expression of HO-1 and protein expression of NQO1. Paeonol also reduced NF-κB, IL-1β, and caspase 3 gene expressions. In conclusion, paeonol offered a gastroprotection dependent on its antioxidant, anti-inflammatory, and antiapoptotic effects.

Emerging role of carbon monoxide in regulation of cellular pathways and in the maintenance of gastric mucosal integrity

Heme oxygenase (HO) catalyzes the degradation of toxic free heme to the equimolar amounts of biliverdin, Fe2+ and concurrently releases of carbon monoxide (CO). CO is nowadays increasingly recognized as an important signaling molecule throughout the body that is involved in many physiological processes and shows multidirectional biological activity. Recent evidence indicates that CO exhibits the anti-inflammatory, anti-proliferative, anti-apoptotic, anti-aggregatory and vasodilatory properties. The cellular mechanisms underlying the activity of CO involve stimulation of cGMP-dependent signaling pathway and large conductance calcium activated K+ channels, the activation of mitogen-activated protein kinases and the nuclear factor k-light chain-enhancer of activated B cells transcription factor pathway. Stimulation of endogenous CO production by HO inducers or the inhalation of CO or the delivery of this gaseous molecule by novel pharmaceutical agents have been found in experimental animal models to be promising in the future therapy of various diseases. CO appears to act as a significant component of the complex mechanism of gastrointestinal (GI) mucosal defense. This gaseous molecule plays an important role in diabetic gastroparesis, prevention of the upper GI mucosal damage, post-operative ileus and the healing of ulcerative colitis. This review focuses on the better understanding mechanisms through which CO contributes to the mechanism of protection, resistance to injury and ulcer healing. It is becoming apparent that the pleiotropic effect of this molecule may increase clinical applicability of CO donors and their implementation in many pharmacological research areas, pharmaceutical industry and health-care system.

Gaseous Mediators in Gastrointestinal Mucosal Defense and Injury

Of the numerous gaseous substances that can act as signaling molecules, the best characterized are nitric oxide, carbon monoxide and hydrogen sulfide. Contributions of each of these low molecular weight substances, alone or in combination, to maintenance of gastrointestinal mucosal integrity have been established. There is considerable overlap in the actions of these gases in modulating mucosal defense and responses to injury, and in some instances they act in a cooperative manner. Each also play important roles in regulating inflammatory and repair processes throughout the gastrointestinal tract. In recent years, significant progress has been made in the development of novel anti-inflammatory and cytoprotective drugs that exploit the beneficial activities of one or more of these gaseous mediators.

Gastroprotective and Antiulcer Effects of Celastrus paniculatus Seed Oil Against Several Gastric Ulcer Models in Rats

Peptic ulcer is a recurrent chronic illness and has become almost a hallmark of the so-called civilized life. In folk medicine, the Celastrus paniculatus plant has been used for the prevention and treatment of various diseases and gastrointestinal disturbances, including dyspepsia and stomach ulcers. The aim of this study is to evaluate the gastroprotective and antiulcer effects of Celastrus paniculatus seed oil (CPO) against several gastric ulcer models in rats. The gastroprotective and antiulcer effects of CPO were evaluated using pylorus-ligated ulcer ethanol- and indomethacin-induced ulcers using rantidine (40 mg/kg per os [PO]) as standard. Gastrointestinal motility was determined by gastric emptying time and gastrointestinal transit ratio. The results of the pharmacological studies of CPO (200 mg/kg, 400 mg/kg) demonstrated effective gastroprotection against ethanol- and indomethacin-induced ulcer models. In pylorus-ligated rats, the seed oil showed gastroprotective activity by decreasing total gastric juice volume and gastric acidity while increasing the gastric pH. The gastroprotection against ethanol and indomethacin is partially attributed to effective inhibition of proinflammatory cytokines, TNF-α and IL-6, and increase in the levels of IL-10. Treatment with CPO in ethanol-induced ulcer rats significantly (p < .05) decreased MDA (malondialdehyde) levels, which were accompanied by an increase in the activities of SOD (superoxide dismutase) and catalase. CPO reduced the rate of gastric emptying but had no effect on gastrointestinal transit. The present findings indicate that CPO has potent gastroprotective effects and support the folkloric usage of the seed oil to treat various gastrointestinal disturbances.

Hydrogen Sulfide and Carbon Monoxide Protect Gastric Mucosa Compromised by Mild Stress Against Alendronate Injury

BACKGROUND

Alendronate is an inhibitor of osteoclast-mediated bone resorption, but its clinical utility is limited due to gastrointestinal complications including bleeding erosions.

AIMS

We studied whether potent vasodilators hydrogen sulfide (H2S) and carbon monoxide (CO) can protect against alendronate-induced gastric lesions in rats exposed to mild stress.

METHODS

Three series (A, B, and C) of Wistar rats received alendronate (150-700 mg/kg i.g., series A) with or without NaHS (5 mg/kg), H2S donor or CORM-2 (5 mg/kg) releasing CO administered i.g. 30 min before alendronate administration (series B) in rats exposed for 3 days before alendronate administration to mild stress (series C). The area of gastric lesions was assessed by planimetry, the gastric blood flow (GBF) was determined by H2-gas clearance technique, and H2S production via CSE/CBS/3-MST activity and the gastric expression of HO-1, HO-2, HIF-1α, NF-κB, iNOS, COX-2, IL-1β, TNF-α, GPx-1 and SOD-2 were analyzed by qPCR or Western blot.

RESULTS

Alendronate dose-dependently produced gastric mucosal lesions and significantly decreased GBF, and these effects were exacerbated by mild stress. NaHS and CORM-2 significantly reduced the alendronate-induced gastric lesions in non-stressed and stressed animals, but only NaHS but not CORM-2 raised H2S production. NaHS and CORM-2 inhibited gastric expression of HIF-1α protein and HO-1, HIF-1α, NF-κB, COX-2, iNOS, IL-1β, TNF-α mRNAs but failed to affect those of HO-2, GPx-1, and SOD-2.

CONCLUSION

Both H2S and CO released from their donors, NaHS and CORM-2, protect gastric mucosa compromised by stress against alendronate-induced gastric damage via mechanism involving downregulation of HIF-1α, NF-κB and proinflammatory factors COX-2, iNOS, IL-1β, and TNF-α.

Gastroprotective effects of sulforaphane and thymoquinone against acetylsalicylic acid-induced gastric ulcer in rats

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) commonly cause gastric ulcers (GUs). We investigated the effects of sulforaphane (SF) and thymoquinone (TQ) in rats with acetylsalicylic acid (ASA)-induced GUs.

MATERIALS AND METHODS

Thirty-five male Wistar-Albino rats were divided into five groups: control; ASA; ASA with vehicle; ASA + SF; and ASA + TQ. Compounds were administered by oral gavage before GU induction. GUs were induced by intragastric administration of ASA. Four hours after GU induction, rats were killed and stomachs excised. Total oxidant status, total antioxidant status, total thiol, nitric oxide, asymmetric dimethylarginine, tumor necrosis factor-alpha levels, superoxide dismutase activity, and glutathione peroxidase activity in tissue were measured. Messenger RNA expression of dimethylarginine dimethylaminohydrolases, heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2, and nuclear factor kappa-light-chain-enhancer of activated B cells were analyzed. Renal tissues were evaluated by histopathologic and immunohistochemical means.

RESULTS

SF and TQ reduced GU indices, apoptosis, total oxidant status, asymmetric dimethylarginine, and tumor necrosis factor-alpha levels, nuclear factor kappa-light-chain-enhancer of activated B cells, and inducible nitric oxide synthase expressions (P < 0.001, P = 0.001). Both examined compounds increased superoxide dismutase activity, glutathione peroxidase activity, total antioxidant status, total thiol, nitric oxide levels, endothelial nitric oxide synthase, dimethylarginine dimethylaminohydrolases, HO-1, nuclear factor erythroid 2-related factor 2, and HO-1 expressions (P < 0.001).

CONCLUSIONS

These results suggest that pretreatment with SF or TQ can reduce ASA-induced GUs via anti-inflammatory, antioxidant, and antiapoptotic effects. These compounds may be useful therapeutic strategies to prevent the gastrointestinal adverse effects that limit nonsteroidal anti-inflammatory drugs use.

Morin protects gastric mucosa from nonsteroidal anti-inflammatory drug, indomethacin induced inflammatory damage and apoptosis by modulating NF-κB pathway

BACKGROUND

Deregulation in prostaglandin (PG) biosynthesis, severe oxidative stress, inflammation and apoptosis contribute to the pathogenesis of nonsteroidal anti-inflammatory drug (NSAID)-induced gastropathy. Unfortunately, most of the prescribed anti-ulcer drugs generate various side effects. In this scenario, we could consider morin as a safe herbal potential agent against IND-gastropathy and rationalize its action systematically.

METHODS

Rats were pretreated with morin for 30 min followed by IND (48 mgkg(-1)) administration for 4 h. The anti-ulcerogenic nature of morin was assessed by morphological and histological analysis. Its effects on the inflammatory (MPO, cytokines, adhesion molecules), ulcer-healing (COXs, PGE(2)), and signaling parameters (NF-κB and apoptotic signaling) were assessed by biochemical, RP-HPLC, immunoblots, IHC, RT-PCR, and ELISA at the time points of their maximal changes due to IND administration.

RESULTS

IND induced NF-κB and apoptotic signaling in rat's gastric mucosa. These increased proinflammatory responses, but reduced the antioxidant enzymes and other protective factors. Morin reversed all the adverse effects to prevent IND-induced gastric ulceration in a PGE2 independent manner. Also, it did not affect the absorption and/or primary pharmacological activity of IND.

CONCLUSIONS

The gastroprotective action of morin is primarily attributed to its potent antioxidant nature that also helps in controlling several IND-induced inflammatory responses.

GENERAL SIGNIFICANCE

For the first time, the study reveals a mechanistic basis of morin mediated protective action against IND-induced gastropathy. As morin is a naturally abundant safe antioxidant, future detailed pharmacokinetic and pharmacodynamic studies are expected to establish it as a gastroprotective agent.

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.

S-allyl cysteine alleviates nonsteroidal anti-inflammatory drug-induced gastric mucosal damages by increasing cyclooxygenase-2 inhibition, heme oxygenase-1 induction, and histone deacetylation inhibition

BACKGROUND AND AIM

Nonsteroidal anti-inflammatory drugs (NSAIDs), the most highly prescribed drugs in the world for the treatment of pain, inflammation, and fever, are associated with gastric mucosal damages including ulcer directly or indirectly. This study was aimed to document the preventive effects of an organosulfur constituent of garlic, S-allyl cysteine (SAC), against NSAIDs-induced gastric damages, as well the elucidation of its pharmacological actions, such as anti-inflammatory, anti-oxidative, and cytoprotective actions.

METHODS

Different doses of SAC were administrated intragastrically before the indomethacin administration. After killing, in addition to gross and pathological evaluations of ulcer, the expressions of inflammatory mediators, including cyclooxygenase-2, prostaglandin E2 , IL-1β, tumor necrosis factor-α, IL-6, and anti-oxidant capacity, were analyzed by Western blot analysis or ELISA, respectively. Transferase deoxytidyl uridine end labeling assay, periodic acid and Schiff staining, F4/80 staining, and CD31 staining were compared among doses of SAC. Detailed documentation of in vitro biological actions of SAC, including NF-κB, histone deacetylator inhibition, phase 2 enzyme, and MAPKs, was performed.

RESULTS

SAC was very effective in preventing indomethacin-induced gastric damages in a low dose through significant decreases in macrophage infiltration as well as restorative action. Indomethacin-induced expressions of inflammatory mediators were all significantly attenuated with SAC in accordance with histone deacetylator inhibition. In addition, SAC significantly increased the total anti-oxidant concentration and mucus secretion, and allows for a significant induction of HO-1. However, these preventive effects of SAC were dependent on dosage of SAC; higher dose above 10 μM paradoxically aggravated NSAID-induced inflammation.

CONCLUSION

Synthetic SAC can be promising therapeutics agent to provide potent anti-inflammatory, anti-oxidative, and mucosa protective effects against NSAID-induced damages.

Nonsteroidal anti-inflammatory drug induces proinflammatory damage in gastric mucosa through NF-κB activation and neutrophil infiltration: anti-inflammatory role of heme oxygenase-1 against nonsteroidal anti-inflammatory drug

Nonsteroidal anti-inflammatory drug (NSAID)-induced mitochondrial oxidative stress (MOS) is an important prostaglandin (PG)-independent pathway of the induction of gastric mucosal injury. However, the molecular mechanism behind MOS-mediated gastric pathology is still obscure. In various pathological conditions of tissue injury oxidative stress is often linked with inflammation. Here we report that MOS induced by indomethacin (an NSAID) induces gastric mucosal inflammation leading to proinflammatory damage. Indomethacin, time dependently stimulated the expression of proinflammatory molecules such as intercellular adhesion molecule 1(ICAM-1), vascular cell adhesion molecule 1(VCAM-1), interleukin1β (IL-1β), and monocyte chemotactic protein-1 (MCP-1) in gastric mucosa in parallel with the increase of neutrophil infiltration and injury of gastric mucosa in rat. Western immunoblotting and confocal microscopic studies revealed that indomethacin induced nuclear translocation of nuclear factor kappa-B (NF-κB) in gastric mucosal cells, which resulted in proinflammatory signaling. The prevention of MOS by antioxidant tryptamine-gallic acid hybrid (SEGA) inhibited indomethacin-induced expression of ICAM-1, VCAM-1, IL-1β, and MCP-1. SEGA also prevented indomethacin-induced NF-κB activation and neutrophil infiltration as documented by chromatin immunoprecipitation studies and neutrophil migration assay, respectively. Heme oxygenase-1 (HO-1), a cytoprotective enzyme associated with tissue repair mechanisms is stimulated in response to oxidative stress. We have investigated the role of HO-1 against MOS and MOS-mediated inflammation in recovering from gastropathy. Indomethacin stimulated the expression of HO-1 and indomethacin-stimulated HO-1 expression was reduced by SEGA, an antioxidant, which could prevent MOS. Thus, the data suggested that the induction of HO-1 was a protective response against MOS developed by indomethacin. Moreover, the induction of HO-1 by cobalt protoporphyrin inhibited inflammation and chemical silencing of HO-1 by zinc protoporphyrin aggravated the inflammation by indomethacin. Thus, NSAID by promoting MOS-induced proinflammatory response damaged gastric mucosa and HO-1 protected NSAID-induced gastric mucosal damage by preventing NF-κB activation and proinflammatory activity.

Gastric body diaphragm-like stricture as a rare complication of nonsteroidal anti-inflammatory drugs

Increased risk due to nonsteroidal anti-inflammatory drugs (NSAIDs) therapy has been observed in patients. Although diaphragm-like stricture in the small bowel and colon induced by NSAIDs therapy has been rarely reported, gastric body diaphragm-like stricture has not been reported. We describe the first case of gastric body diaphragm-like stricture due to NSAIDs in a 44-year-old male patient who was successfully treated by an endoscopic approach to avoid complicated surgery. This case highlights new insight into the disadvantages of NSAIDs and provides new data for future clinical studies.

Gastroduodenal mucosal defense

PURPOSE OF REVIEW

To review recent developments in the field of gastroduodenal mucosal defense.

RECENT FINDINGS

Research in the field of gastroduodenal mucosal defense is shifting from animal models of mucosal injury towards the elucidation of molecular mechanisms that protect the mucosa at the cellular level. Accordingly, the recent literature is focused on endogenous antioxidants such as mitochondrial superoxide dismutase (SOD), and heme oxygenase-1, mucosal receptors such as the Toll-like receptors and protease-activated receptors, endogenous proteins with protective effects such as the matrix metalloproteinases, heat-inducible factors and trefoil factors, protective functions of submucosal mononuclear cells, junctional proteins affecting mucosal permeability, and hormone-mediated protective mechanisms mediated by estrogens, vasoactive peptides, and other hormones.

SUMMARY

These new published findings contribute to our overall understanding of gastroduodenal defense and suggest innovative avenues of future research and possible novel therapeutic targets.