Roles of oxidative stress in stomach disorders

Natural xanthones as modulators of the Nrf2/ARE signaling pathway and potential gastroprotective agents

Oxidative stress is implicated in the initiation, pathogenesis, and progression of various gastric inflammatory diseases (GID). The prevalence of these diseases remains a concern along with the increasing risks of adverse effects in current clinical interventions. Hence, new gastroprotective agents capable of inhibiting oxidative stress by modulating cellular defense systems such as the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway are critically needed to address these issues. A candidate to solve the present issue is xanthone, a natural compound that reportedly exerts gastroprotective effects via antioxidant, anti-inflammatory, and cytoprotective mechanisms. Moreover, xanthone derivatives were shown to modulate the Nrf2/ARE signaling pathway to counter oxidative stress in both in vitro and in vivo models. Thirteen natural xanthones have demonstrated the ability to modulate the Nrf2/ARE signaling pathway and have high potential as lead compounds for GID as indicated by their in vivo gastroprotective action-particularly mangiferin (2), α-mangostin (3), and γ-mangostin (4). Further studies on these compounds are recommended to validate the Nrf2 modulatory ability in relation to their gastroprotective action.

Helicobacter pylori infection and oxidative stress

Helicobacter pylori (H. pylori) infection promotes the migration of polymorphonuclear leukocytes from the gastric mucosal microcirculation through chemokine induction, leading to the excessive production of ROS. Like eukaryotes, H. pylori possesses superoxide dismutase and catalase, and is resistant to ROS from host polymorphonuclear leukocytes. Oxidants such as monochloramine produced by ROS cause chronic inflammation in the gastric mucosa. H. pylori-derived virulence factor m1-type VacA induces intracellular ROS accumulation and autophagy, which degrades the H. pylori-derived oncoprotein, CagA. In CD44v9-positive gastric cancer stem-like cells, reduced-type glutathione levels increase within the cell because of the cystine transporter on the cell surface, wherein oxidative stress-induced autophagy no longer occurs. As a result, the oncoprotein CagA accumulates in the cells, thus becoming tumorigenic.

Dose-dependent protective effects of Lactobacillus rhamnosus GG against stress-induced ulcer

BACKGROUND

Stress-related diseases are on the rise and stress is one of the common factors that lead to ulcer. Stress-induced mucosal bleeding is a serious complication observed in many critically ill patients. Due to the harmful side effects of proton pump inhibitors, natural and active alternative treatment methods for peptic ulcer treatment that are safe in terms of side effects are an urgent need for human health. We aimed to investigate the dose-dependent protective effects of Lactobacillus rhamnosus GG (LGG) against stress ulcer induced by cold restraint stress in rats. This study was performed in a total of 42 rats, in control group (C), stress group (S), pantoprazole (20 mg kg-1 day-1) group (P), LGG (3 × 108 cfu mL-1 day-1) + stress group (M1), LGG (15 × 108  mL-1 day-1) + stress group (M5) and LGG (30 × 108  mL-1 day-1) + stress group (M10) (each n = 7). Ulceration areas (mm2) were determined quantitatively with ImageJ software. Glucocorticoid, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels were determined by ELISA and malondialdehyde levels were determined by spectrophotometric measurement. Histopathological examinations were performed in gastric tissue.

RESULTS

Therapeutic dose of LGG increased CAT, SOD and GPx levels; prevented excessive activation of the hypothalamic-pituitary-adrenal axis; reduced ulceration and bleeding in the gastric mucosal layer; and provided stabilization of mast cells.

CONCLUSIONS

We can suggest that LGG may be beneficial for reducing the negative effects of stress on the body, for protecting against ulcer disease and for reducing or preventing the risk of stress-induced gastrointestinal bleeding in patients staying in intensive care units. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Fermented Gold Kiwi for Improved Gastric Health: Evaluation of Efficacy and Safety in a Randomised, Double-Blind, Placebo-Controlled Trial

This randomised double-blind placebo-controlled trial evaluated the efficacy and safety of fermented gold kiwi (FGK) in improving gastrointestinal health. A total of 100 participants were enrolled and randomly assigned to treatment or placebo groups. Over 8 weeks, the participants consumed an FGK or placebo preparation daily. Primary outcomes included changes in gastrointestinal symptoms assessed using the Gastrointestinal Symptom Rating Scale (GSRS) and the Korean version of the Nepean Dyspepsia Index (NDI-K), as well as quality of life assessed using the Functional Dyspepsia-related Quality of Life questionnaire. The FGK group showed significant improvements in GSRS and NDI-K total and subdomain scores compared with the placebo group. Moreover, the quality of life scores were significantly better in the FGK group than in the placebo group. Safety evaluations revealed no significant adverse events or clinically meaningful changes upon assessing laboratory test results. This study demonstrated that FGK is a safe and effective dietary supplement for improving gastrointestinal health in adults with gastrointestinal symptoms.

Enhanced upregulation of SIRT1 via pioglitazone and ligustrazine confers protection against ethanol-induced gastric ulcer in rats

Gastric ulcer is a disturbing disease that impacts many people worldwide. Pioglitazone (Piog), a thiazolidinedione, and ligustrazine (Ligu), a natural component of Ligusticum chuanxiong possess gastroprotective properties. However, the underlying mechanism is not well elucidated. The present study aimed to investigate the gastroprotective effects of Piog (15 mg/kg, p.o.), Ligu (15 mg/kg, p.o.), and their combination against ethanol-induced gastric ulcer in rats. Omeprazole (10 mg/kg) was used as a standard. Pre-treatment for 7 days with Piog, Ligu, and (Piog+Ligu) effectively alleviated ethanol-predisposed oxidative stress and inflammation through restoring HO-1, GSH, and SOD tissue levels and decreasing elevated MDA, TNF-α, ICAM, I-NOS, and IL-1β contents. Moreover, Piog, Ligu, and (Piog+Ligu) markedly inhibited the ethanol-induced increase of gastric NF-KB and BAX. In contrast, this pre-treatment regimen significantly accelerated protein expression of SIRT1, Nrf2, and Bcl-2, along with autophagic proteins, ATG5 and Beclin. Interestingly, macroscopic, histopathological examination and mucin content were in harmony with previous results, where pre-treatment with Piog, Ligu, and (Piog+Ligu) showed a declined mucosal injury as evidenced by the remarkable decrease of the ulcer area percentage by 62.3%, 38.7%, and 91.2%, respectively, compared to the ethanol-ulcerated group. In conclusion, Piog and Ligu exhibited remarkable gastroprotective properties. Our study was the first to show that Piog, Ligu, and (Piog+Ligu) ameliorated oxidative stress, inflammation, and apoptosis and accelerated the autophagic process via the upregulation of the upstream SIRT1 protein. It is worth mentioning that future studies are needed to pave the way for the clinical use of Piog and Ligu as gastro-protective agents.

Anti-inflammatory, anti-oxidant and anti-ulcer activities of aqueous lyophilizate of Markhamia lutea (Bignoniaceae)

OBJECTIVES

This work was carried out with a view to determining the antioxidant, anti-inflammatory and anti-ulcer properties of the aqueous lyophilized extract of Markhamia lutea.

METHODS

In vitro proteinases inhibition, albumin denaturation, hemolysis of red blood cells by heat, inhibition of the proton pump H+/K+ATPase, FRAP (Ferric reducing antioxidant power) and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays were performed. In vivo, cold water immersion-induced ulceration and methylene blue-induced ulceration was used to determine the anti-ulcer properties of the lyophilizate (100, 200 and 300 mg/kg).

RESULTS

In vitro, the lyophilizate (400 μg/mL) significantly inhibited protein denaturation (66.65 %), hemolysis of red blood cells (56.54 %), proteinase activity (69.22 %); then the IC50 was 26.31 μg/mL on proton pump activity. It has also developed a strong ferric reducing antioxidant power (EC50=52.96 mmol FeSO4/g) as well as free radicals scavenging activity (EC50=22.38 μg/mL). In vivo, the aqueous lyophilizate (200 and 300 mg/kg) protected the gastric mucosa (70.68 and 79.00 % protection respectively) and reduced (p<0.05) acetylcholine, calcium and corticosterone concentrations. A decrease in malondialdehyde level, an increased glutathione level and an increased in catalase and SOD activities were recorded. In the methylene blue test, it significantly increased gastric fluid pH, while reducing gastric volume and improving hematological parameters in ulcer animals. In addition, the histological sections show that the aqueous lyophilizate of M. lutea protected the gastric mucosa from the deleterious effects of stress.

CONCLUSIONS

The aqueous lyophilizate of M. lutea has anti-ulcer properties thanks to its anti-inflammatory, antioxidant and anti-secretory properties.

Comparative Assessment of the Anti-Helicobacter pylori Activity and Gastroprotective Effects of Three Herbal Formulas for Functional Dyspepsia In Vitro

Helicobacter pylori has been implicated in various gastrointestinal disorders, including functional dyspepsia. This study aimed to compare the anti-H. pylori activity and gastroprotective effects of three typical herbal formulas used for gastrointestinal disorders in Korea: Shihosogan-tang (ST), Yijung-tang (YT), and Pyeongwi-san (PS). Firstly, we assessed the total phenolic and flavonoid contents, as well as the antioxidative capacity. Additionally, we evaluated the antibacterial effect on H. pylori using an ammonia assay, minimum inhibitory concentration (MIC) test, and the disk agar diffusion method. Furthermore, we examined alterations in the gene expression of tight junction proteins, pro-inflammatory cytokines, and cellular vacuolation using an AGS cell model infected with H. pylori. While ST exhibited a higher total phenolic content, superior free radical scavenging, and inhibition of H. pylori compared to YT and PS, YT more evidently inhibited gastric cellular morphological changes such as vacuolation. All formulations significantly ameliorated changes in inflammatory and gastric inflammation-related genes and cellular morphological alterations induced by H. pylori infection. Overall, the present in vitro study suggests that all three herbal formulas possess potential for ameliorating gastrointestinal disorders, with ST relatively excelling in inhibiting H. pylori infection and inflammation, while YT potentially shows greater efficacy in directly protecting the gastric mucosa.

Alginate Oligosaccharides Protect Gastric Epithelial Cells against Oxidative Stress Damage through Induction of the Nrf2 Pathway

Gastric diseases represent a significant global public health challenge, characterized by molecular dysregulation in redox homeostasis and heightened oxidative stress. Although prior preclinical studies have demonstrated the cytoprotective antioxidant effects of alginate oligosaccharides (AOSs) through the Nrf2 pathway, whether such mechanisms apply to gastric diseases remains unclear. In this study, we used the GES-1 gastric cell line exposed to hydrogen peroxide (H2O2) as a damage model to investigate the impact of AOS on cell viability and its associated mechanisms. Our results revealed that pre-incubation with AOS for either 4 h or 24 h significantly improved the viability of GES-1 cells exposed to H2O2. In addition, AOS reduced the intracellular ROS levels, activating the Nrf2 signaling pathway, with increased Nrf2 protein and mRNA expression and a significant upregulation of the target genes HO-1 and NQO1. The activation of Nrf2 was correlated with decreased Keap1 protein expression and an increased level of the autophagy protein p62/SQSTM1, suggesting the activation of Nrf2 through a noncanonical pathway. This study suggests that AOS is a potential treatment for protecting gastric epithelial cells from oxidative stress by activating the p62/SQSTM1-Keap1-Nrf2 axis and laying the foundation for future investigations about its specific therapeutic mechanisms.

Efficacy evaluation of upper gastrointestinal endoscopy screening for secondary prevention of gastric cancer using the standardized detection ratio during a medical check-up in Japan

We used standardized detection ratio to evaluate the quality of nasal upper gastrointestinal endoscopy screening for the secondary prevention of gastric cancer, and examined the gastric cancer risk in the era of total Helicobacter pylori (H. pylori) eradication. We performed 21,931 upper gastrointestinal endoscopies, 77 subjects were diagnosed with gastric cancer. Of these, 28 had gastric cancer after H. pylori eradication, 47 had gastric cancer with H. pylori-positive or others, and 2 had H. pylori-negative gastric cancer. The Standardized detection ratios for men and women were 5.33 and 4.82, respectively. Multivariable logistic regression analyses performed exclusively on first endoscopy subjects, excluding H. pylori-negative gastric cancer, revealed that smoking was a risk factor for developing gastric cancer (adjusted odds ratio, 3.31; 95% confidence interval, 1.65-6.64; p = 0.001). A statistically significant interaction was found between daily alcohol consumpption and H. pylori eradication on gastric cancer development (p = 0.005). In conclusion, relatively high standardized detection ratio values suggest that an appropriate endoscopic diagnosis of gastric cancer should be performed during a medical check-up. Smoking is a risk factor for developing gastric cancer, and continued alcohol consumption suggests a possible risk for developing gastric cancer after H. pylori eradication.

Antiulcer activity of Mauritia flexuosa L.f. (Arecaceae) pulp oil: An edible Amazonian species with functional properties

Mauritia flexuosa, known as buriti in Brazil, is a widespread palm tree in Amazonia. It has many ethnobotanical uses, including food, oil, and medicine. The oil obtained from buriti's fruit pulp has high levels of monounsaturated fatty acids, carotenoids, and tocopherols, and is used in the food, cosmetic, and pharmaceutical industries for its antioxidant properties. Many biological activities have been reported for buriti oil, such as antioxidant, antimicrobial, chemopreventive, and immunomodulatory. Due to its high content of bioactive compounds, buriti oil is considered a functional ingredient with possible benefits in preventing oxidative stress and chronic diseases, particularly in the gastrointestinal tract. Peptic ulcer disease is a multifactorial disorder, involving lesions in the stomach and duodenum mucosa, which has a complex healing process. In this context, some nutrients and bioactive compounds help the maintenance of gastrointestinal mucosal integrity and function, such as carotenoids, tocopherols, and unsaturated fatty acids, which makes buriti oil an interesting candidate to be used in the prevention and management of gastrointestinal diseases. This study aimed to evaluate the gastroprotective and antiulcer effects of buriti oil and its possible mechanisms of action. Buriti oil reduced the ulcerative area and lipid peroxidation induced by ethanol. The gastroprotective activity of buriti oil partially depends on nitric oxide and sulfhydryl compounds. In acetic acid-induced gastric ulcers, buriti oil accelerated healing and stimulated the formation of new gastric glands. These results demonstrated the potential of buriti oil as a functional ingredient to promote health benefits in the gastrointestinal tract.

The Therapeutic Potency of Silver/Chitosan, Silver/Saponin and Chitosan/ Saponin Nanocomposites on Ethanol-induced Gastric Ulcers in Wistar Rats

BACKGROUND

The annual incidence of peptic ulcer disease is estimated to be four million cases worldwide, with an average lifetime risk of 7.5% in individuals of all ages. Polymer nanocomposites have novel prospects in the field of modern medicine.

OBJECTIVE

The present research endeavors to assess the therapeutic efficacy of nanoparticles composed of silver/chitosan, silver/saponin, and chitosan/saponin against gastric ulcers induced by ethanol in Wistar rats.

METHODS

Forty-eight rats were randomly split into eight groups of the same size. Oral ethanol (5 ml/kg of body weight) was given to all rat groups except the control one for 1 hour before treatment. Control and ulcer groups of rats were given distilled water orally. The rats in the other groups were given orally 1/10 LD50 of each treatment as follows: AgNPs, chitosan NPs, Saponin, AgNPs-Chitosan NPs, AgNP-Saponin, and chitosan-Saponin NPs.

RESULTS

NP-treated groups showed a significant increase in the gastric juice pH, glutathione reduced, catalase, and nitric oxide while gastric juice volume, ulcer index, and malondialdehyde levels decreased compared with the ulcer group. Histopathological investigation of stomach showed improvement in NPs groups specially in the chitosan-Saponin NPs group.

CONCLUSION

The current study revealed that silver-chitosan, silver-saponin and chitosansaponin nanocomposites effectively treat gastric ulcers. Chitosan-Saponin nanoparticles showed high therapeutic effectiveness against gastric ulcer in rats.

Protective Effect of Prosopis Farcta Fruit Aqueous Extract Against Oxidative Stress Caused By Ethanol in Albino Rats

Prosopis farcta was previously used in folk medicine as a dry fruit to relieve pain before its active biological components that contribute to this were known. This study assessed the effectiveness of a dry fruit extract of P. farcta by measuring the indicators of inflammation in albino rats after they were dosed with ethanol. As such, looking at the antioxidant potential of P. farcta fruit aqueous extract (PFFAE) in resistance to ethanol's harm in rats given ethanol showed a notable increase in serum C reactive protein (CRP), malondialdehyde (MDA), CRP/ALB ratio (CAR), and WBC count. At the same time, glutathione peroxidase (GPx) and albumin were markedly reduced. PFFAE diminished ethanol-induced amounts of CRP, MDA, and CAR in plasma; additionally, it strengthened the ethanol-induced decline in GPx activity, and albumin had no apparent effect on the ESR level. Consequently, the current findings demonstrate that PFFAE counteracts the toxicity of ethanol and has a protective impact against the ethanol effect.

Unravelling the Gastroprotective Potential of Kefir: Exploring Antioxidant Effects in Preventing Gastric Ulcers

The present study was conducted to evaluate the protective effect of milk kefir against NSAID-induced gastric ulcers. Male Swiss mice were divided into three groups: control (Vehicle; UHT milk at a dose of 0.3 mL/100 g), proton pump inhibitor (PPI; lansoprazole 30 mg/kg), and 4% milk kefir (Kefir; 0.3 mL/100 g). After 14 days of treatment, gastric ulcer was induced by oral administration of indomethacin (40 mg/kg). Reactive oxygen species (ROS), nitric oxide (NO), DNA content, cellular apoptosis, IL-10 and TNF-α levels, and myeloperoxidase (MPO) enzyme activity were determined. The interaction networks between NADPH oxidase 2 and kefir peptides 1-35 were determined using the Residue Interaction Network Generator (RING) webserver. Pretreatment with kefir for 14 days prevented gastric lesions. In addition, kefir administration reduced ROS production, DNA fragmentation, apoptosis, and TNF-α systemic levels. Simultaneously, kefir increased NO bioavailability in gastric cells and IL-10 systemic levels. A total of 35 kefir peptides showed affinity with NADPH oxidase 2. These findings suggest that the gastroprotective effect of kefir is due to its antioxidant and anti-inflammatory properties. Kefir could be a promising natural therapy for gastric ulcers, opening new perspectives for future research.

Effect of a blend of magnesium oxide on Equine Squamous Gastric Disease in young trotter horses under training

BACKGROUND

Equine squamous gastric disease (ESGD), as part of the equine gastric ulcer syndrome (EGUS), are common in racing horses. The use of buffering feed supplements to treat and/or prevent gastric ulcers is an option to control this condition.

OBJECTIVE

The purpose of this study was to evaluate the effect of a 30-day supplementation with a blend of magnesium oxide (MgO) on ESGD scores in trotters under training.

METHODS

Forty-two young trotters were submitted to a gastroscopic evaluation to assess their ESGD score and were randomly assigned in a group supplemented with MgO or in a control group. After 30 days, a second evaluation by gastroscopy was performed. The effect of the MgO supplementation was assessed by comparing the evolution of the ESGD score in supplemented and control groups between day 0 and day 30.

RESULTS

The results confirm the high prevalence of EGUS in young Trotters. The supplementation significantly decreased the ESGD scoring in the supplemented group whereas the control group remain unchanged.

CONCLUSION

The oral MgO supplementation was efficient to control ESGD in the population studied.

Protective Effect of the Phycobiliproteins from Arthrospira maxima on Indomethacin-Induced Gastric Ulcer in a Rat Model

Gastric ulcers (GU) constitute a disease with a global prevalence ≈ 8.09 million. Of their causes, non-steroidal anti-inflammatory drugs (NSAIDs) such as indomethacin (IND) rank as the second most frequent etiologic agent. The pathogenic process of gastric lesions is given by the overproduction of oxidative stress, promotion of inflammatory processes, and inhibition of prostaglandin synthesis. Spirulina Arthrospira maxima (SP) is a cyanobacterium with a wide variety of substances with high nutritional and health values such as phycobiliproteins (PBPs) that have outstanding antioxidant activity, anti-inflammatories effects, and accelerate the wound healing process. This study aimed to determine the protective effect of PBPs in GU induced by IND 40 mg/kg. Our results show that the PBPs protected against IND-induced damage with a dose-dependent effect. At a dose of 400 mg/kg, a marked decrease in the number of lesions is observed, as well as the recovery of the main markers of oxidative stress damage (MDA) and antioxidant species (SOD, CAT, GPx) at close to baseline levels. The evidence derived from the present investigation suggests that the antioxidant effect of PBPs, together with their reported anti-inflammatory effects to accelerate the wound healing process, is the most reliable cause of their antiulcerogenic activity in this GU model.

Role of Helicobacter pylori in Gastric Carcinoma: A Review

Gastric cancer (GC) is one of the leading causes of cancer-related deaths globally. Gastritis caused by Helicobacter pylori (H. pylori) is a potent cause of gastrointestinal malignancies. The majority of all humans on the planet have H. pylori invasion in their stomachs, yet only a few diseased people develop GC. The human gastrointestinal system contains a broad population of microorganisms in addition to H. pylori. H. pylori heterogeneity has been studied because not all H. pylori diseases result in cancer. Individuals in the adult age group account for the bulk of gastric carcinoma cases. H. pylori has various strains, which is beneficial for its survival in host cell epithelium for a longer duration of time. Along with H. pylori, oral microbes have a major role in the pathogenicity of gastric carcinoma. The complex ecology of oral microbiota helps to defend against infections, preserve homeostasis, and regulate the immune system. In contrast, oral microbiota is involved in various mechanisms like anti-apoptotic activity, suppression of the immune system of the host, and initiation of chronic inflammation. These oral microbes are also responsible for the development of mutations. Interactions between the host immune system and bacteria promote the progression of cancer. For this review, various research articles were studied, and information was collected using databases like PubMed and Google Scholar. This review emphasizes on the role of H. pylori in gastric carcinoma, its pathogenesis, the role of various virulence factors and risk factors related to it, the role of oral microbiota in gastric carcinoma pathogenesis, diagnostic modalities, treatment options, and preventive measures for gastric carcinoma.

Potential effects of carbon monoxide donor and its nanoparticles on experimentally induced gastric ulcer in rats

The prevalence of gastric ulcers is increasing worldwide, especially those brought on by non-steroidal anti-inflammatory drugs (NSAIDS), so prevention is extremely crucial. The protective potential of carbon monoxide (CO) in several inflammatory disorders has been clarified. The goal of the current study was to investigate the gastroprotective effect of CO produced by its pharmacological donor (CORM2) and its nanoparticles (NPs) against indomethacin (INDO)-induced ulcers. Investigations on CORM2's dose-dependent effects were also conducted. For induction of gastric ulcer, 100 mg kg^-1 of INDO was given orally. Before ulcer induction, CORM2 (5, 10, and 15 mg kg^-1), CORM2 nanoparticles (5 mg kg^-1), or ranitidine (30 mg kg^-1) were given intraperitoneally for 7 days. Ulcer score, gastric acidity, gastric contents of malondialdehyde (MDA), nitric oxide (NO), heme oxygenase-1 (HO-1), and carboxyhemoglobin (COHb) blood content were estimated. Additionally, gene expression of nuclear factor erythroid 2-related factor 2 (NRF2) and immunohistochemical staining of cyclooxygenase-1 (COX-1) as well as cyclooxygenase-2 (COX-2) were analyzed. Results demonstrated a substantial dose-dependent decrease in ulcer score, pro-inflammatory indicators, and oxidative stress markers with CORM2 and its NPs. Furthermore, CORM2 and its NPs markedly increased NRF2, COX-1, and HO-1, but CORM2 NPs outperformed CORM2 in this regard. In conclusion, the CO released by CORM2 can protect against INDO-induced gastric ulcers dose dependently, and the highest used dose had no effect on COHb concentration.

Antioxidants: Structure-activity of plant polyphenolics

The excessive accumulation of reactive oxygen species (ROS)/free radicals can lead to abnormal oxidation of biomolecules such as proteins, lipids, fats, carbohydrates and nucleic acids in human organisms. Accordingly, endogenous oxidative stress induces the progressive development of various chronic diseases like rheumatoid arthritis, cancers, cardiovascular risks, diabetes, digestive ulcers, hypertension, obesity, neurological disorders, and age-related complications. Therefore, anti-oxidant defense mechanisms are needed to control/prevent the unbalanced molecular oxidative damage. Indeed, the oxidative stress arises from both endogenous and exogenous factors such as smoking, alcohol, medications, air pollution, sunlight, lifestyle disorders, and metabolic processes. Therefore, consumption of fruits, vegetables, grains, beverages, and leafy vegetables rich in antioxidants may inhibit or treat oxidative damage accompanying diseases. From this aspect, dietary foods are rich in various antioxidant metabolites such as flavonoids, vitamin A, C, E, phenolic acids, curcumin, stilbenes, anthocyanins, etc., which promote healthy life and nutritional benefits. Additionally, various studies have also proven that foods rich in antioxidants interact with reactive species to prevent cell damage(s) or therapeutic pathways for diseases. Although, there are various myths about the antioxidant mechanism(s), the optimal dosage of antioxidants can show beneficial pharmacological activities against various molecular oxidation paths.

The impact of monthly air pollution exposure and its interaction with individual factors: Insight from a large cohort study of comprehensive hospitalizations in Guangzhou area

Background

Although the association between short-term air pollution exposure and certain hospitalizations has been well documented, evidence on the effect of longer-term (e. g., monthly) air pollution on a comprehensive set of outcomes is still limited.

Method

A total of 68,416 people in South China were enrolled and followed up during 2019-2020. Monthly air pollution level was estimated using a validated ordinary Kriging method and assigned to individuals. Time-dependent Cox models were developed to estimate the relationship between monthly PM₁₀ and O₃ exposures and the all-cause and cause-specific hospitalizations after adjusting for confounders. The interaction between air pollution and individual factors was also investigated.

Results

Overall, each 10 μg/m³ increase in PM₁₀ concentration was associated with a 3.1% (95%CI: 1.3%-4.9%) increment in the risk of all-cause hospitalization. The estimate was even greater following O₃ exposure (6.8%, 5.5%-8.2%). Furthermore, each 10 μg/m³ increase in PM₁₀ was associated with a 2.3%-9.1% elevation in all the cause-specific hospitalizations except for those related to respiratory and digestive diseases. The same increment in O₃ was relevant to a 4.7%-22.8% elevation in the risk except for respiratory diseases. Additionally, the older individuals tended to be more vulnerable to PM₁₀ exposure (P _interaction: 0.002), while the alcohol abused and those with an abnormal BMI were more vulnerable to the impact of O₃ (P _interaction: 0.052 and 0.011). However, the heavy smokers were less vulnerable to O₃ exposure (P _interaction: 0.032).

Conclusion

We provide comprehensive evidence on the hospitalization hazard of monthly PM₁₀ and O₃ exposure and their interaction with individual factors.

Protective Effect of Polyphenols Purified from Mallotus oblongfolius on Ethanol-Induced Gastric Mucosal Injury by Regulating Nrf2 and MAPKs Pathways

Mallotus oblongifolius (MO), which is rich in polyphenols, is a characteristic tea resource with medicinal value. In this study, a total of 45 polyphenolic components of MO, including narirutin, isoquercitrin, rutin and digallic acid, were identified by UPLC-Q-TOF/MS analysis. In addition, the gastroprotective effect of Mallotus oblongifolius polyphenols (MOP) on ethanol-induced gastric mucosal injury in rats was investigated. The rats received anhydrous ethanol after continuous gavage of MOP or lansoprazole for one week. In addition, the macro- and micro-damage induced by ethanol in the gastric tissue was significantly reduced after MOP pretreatment for one week. Further analysis showed that MOP prevented ethanol-induced acute gastric mucosal injury by increasing the expression of antioxidant enzymes (SOD, CAT, GSH-Px) and decreasing the expression of reactive oxygen species (ROS), lipid oxidation product (MDA) and myeloperoxidase (MPO). Meanwhile, MOP inhibited the phosphorylation of p38/ERK/JNK and promoted the activation of the Nrf2 pathway. These results suggested that MOP may be a promising therapeutic target for the prevention of ethanol-induced gastric mucosal injury by improving oxidative stress, inhibiting the p38/ERK/JNK signaling pathways and activating Nrf2 expression.

Anti-Oxidant and Anti-Inflammatory Effects of Astaxanthin on Gastrointestinal Diseases

A moderate amount of reactive oxygen species (ROS) is produced under normal conditions, where they play an important role in cell signaling and are involved in many aspects of the immune response to pathogens. On the other hand, the excessive production of ROS destructs macromolecules, cell membranes, and DNA, and activates pro-inflammatory signaling pathways, which may lead to various pathologic conditions. Gastrointestinal (GI) mucosa is constantly exposed to ROS due to the presence of bacteria and other infectious pathogens in food, as well as alcohol consumption, smoking, and the use of non-steroidal anti-inflammatory drugs (NSAID). Prolonged excessive oxidative stress and inflammation are two major risk factors for GI disorders such as ulcers and cancers. Bioactive food compounds with potent anti-oxidant and anti-inflammatory activity have been tested in experimental GI disease models to evaluate their therapeutic potential. Astaxanthin (AST) is a fat-soluble xanthophyll carotenoid that is naturally present in algae, yeast, salmon, shrimp, and krill. It has been shown that AST exhibits protective effects against GI diseases via multiple mechanisms. Residing at the surface and inside of cell membranes, AST directly neutralizes ROS and lipid peroxyl radicals, enhances the activity of anti-oxidant enzymes, and suppresses pro-inflammatory transcription factors and cytokines. In addition, AST has been shown to inhibit cancer cell growth and metastasis via modulating cell proliferation-related pathways, apoptosis, and autophagy. Considering the potential benefits of AST in GI diseases, this review paper aims to summarize recent advances in AST research, focusing on its anti-oxidant and anti-inflammatory effects against gastric and intestinal ulcers and cancers.

Efficiency evaluation of Amlodipine combined with N-acetylcysteine on Indomethacin-induced gastritis in rats

Introduction: It is a well-known phenomenon that nonsteroidal anti-inflammatory drugs cause gastric mucosal damage. Amlodipine is a third generation dihydropyridine-type calcium channel blocker; it can inhibit inflammatory cytokines and enhance antioxidant defenses. N-acetylcysteine can act both as a precursor of reduced glutathione and as a direct ROS scavenger. Moreover, N-acetylcysteine has been purported to have anti-inflammatory properties.

Materials and methods: 34 albino Wistar rats were used. The model of gastritis was induced by subcutaneous Indomethacin prepared in 5% sodium bicarbonate administered at a dose rate of 9 mg/kg for two days at 24h intervals. N-acetylcysteine (500 mg/kg), Amlodipine (10 mg/kg) and N-acetylcysteine (500 mg/kg) combined with Amlodipine (5 mg/kg) were administrated for seven consecutive days beginning 24 h after the first Indomethacin injection. Rats were sacrificed under ether anesthesia on the 8th day. The stomach injury was assessed by macroscopic damage and histological study.

Results and discussion: The results showed that macroscopic stomach damage scores caused by administration of Indomethacin did not significantly decrease by administration of N-acetylcysteine alone (p&gt;0.05), but it decreased significantly by administration of Amlodipine alone or by its combination with N-acetylcysteine (p&lt;0.05). Microscopic stomach damage scores did not significantly decrease by administration of Amlodipine or N-acetylcysteine alone (p&gt;0.05), but they decreased significantly by administering the combination of Amlodipine with N-acetylcysteine (p&lt;0.05). Administration of Amlodipine with N-acetylcysteine showed significant reduction in the severity of the gastric inflammation induced by Indomethacin, which was evidenced macroscopically and microscopically.

Conclusion: This study concluded that administration of Amlodipine with N-acetylcysteine produce obvious enhancement in gastritis induced by Indomethacin.

Graphical abstract:

Snail Mucus Protective Effect on Ethanol-Induced Gastric Ulcers in Mice

Nowadays, an increased interest in natural compounds with preventive or therapeutic potential for various diseases has been observed. Given the involvement of oxidative stress in the pathogenesis of gastric ulcer (GU) and the wide range of bioactive compounds isolated from snails, this study aimed to investigate the protective effect of Cornu aspersum (Müller, 1774) mucus on ethanol-induced GUs. Male albino mice were divided into Control, Ethanol, Mucus + Ethanol and Mucus + Omeprazole treated groups. The GUs were induced by administration of 96% ethanol (10 mL/kg, per os). One hour before ulcer induction, the mice of Mucus + Ethanol group were pretreated with mucus (20 mg/kg, per os), and the mice of Mucus + Omeprazole group were pretreated with omeprazole (20 mg/kg, per os). Ethanol administration caused grave lesions of gastric mucosa and a significant decrease of glutathione (GSH) and superoxide dismutase (SOD), catalase, and glutathione reductase (GR) activities. In the animals with mucus or omeprazole pre-administration compared to the Ethanol group, the following were observed: only a small number of hemorrhagic fields, significantly reduced GU index with calculated 73% protection by mucus and 78% protection by omeprazole, and significant recovery of mucosal GSH and SOD and GR activities. In addition, the mucus inhibited Helicobacter pylori growth. Thus, the protective effect of C. aspersum mucus on both gastric mucosa and gastric antioxidant potential in ethanol-induced GU model suggests that it may serve as a good tool for prevention of this disease.

Gastroprotective Effects of Fermented Gold Kiwi (Actinidia chinenesis L.) Extracts on HCl/EtOH-Induced Gastric Injury in Rats

Gastritis and gastric ulcers caused by stressors such as drinking are common. The ability of functional foods to protect the stomach more effectively and reduce the risk of side effects is of interest. The fermentation process can increase the preservation and bioactive compound content of kiwi fruits. This study produced fermented kiwi powder using two lactic acids separated from gold kiwi fruits. Gold kiwi puree (Actinidia chinensis L.) was fermented using beneficial bacteria. Fermentation increased the content of bioactive compounds such as organic acids, flavonoids, and carotenoids. We investigated whether fermented gold kiwi (FGK) extract had antioxidant and gastric protective effects in an HCl/EtOH-induced gastritis animal model and pyloric ligation animal model. FGK increased radical scavenging activity in a dose-dependent manner. In the gastritis model, FGK inhibited inflammation-related factors such as iNOS, COX-2, IL-6, and TNF-α, while increasing the expression of the protective molecule PGE2. Furthermore, FGK administration improved gastric lesion site appearance, clinical symptoms, and mucosal thickness in rats. FGK also reduced gastric fluid volume, free acidity, total acidity, and pepsin activity in the pyloric ligation model. These results suggest that FGK can decrease the inflammatory response and protect the gastric mucosa. FGK therefore has the potential to prevent and treat gastritis and gastric ulcers.

Gastroprotective effect of low dose Eugenol in experimental rats against ethanol induced toxicity: Involvement of antiinflammatory and antioxidant mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Syzygium aromaticum L. volatile oil (clove oil) has been traditionally used for various stomach disorders including inflammatory conditions. Eugenol is the major constituent present in the volatile oil, and it has been established as a gastroprotective agent through many published studies, but the exact and complete mechanism of ulcer protection is not delineated yet. Moreover, it plays precisely the opposite effect in higher dose in antiulcer properties with worsening the ulcer at a higher dose.

AIM

This study aims to carry out the prophylactic cytoprotective effect of eugenol with single low doses and explore the probable interrelated underlying transcriptional and translational level mechanism of cytoprotection such as antioxidative, anti-inflammatory, mucous generation in rats using ethanol-induced ulcer model.

METHODS

Rats were administered with different doses of eugenol before ethanol intragastrically. The effects of the eugenol on mucous production, Nitric oxide generation, PGE2 synthesis, lipid peroxidation were recorded together with cytokines measurement in the blood. TNF-α and IL-6, two key cytokines, were also studied in specific. In addition, studies on the immunohistochemical and gene expression of HSP70 and iNOS indicators have been conducted.

RESULTS

According to our findings, Eugenol substantially reduced the ulcer index and completely protected the mucosa from lesions. By restoring the lowered GSH and NP-SH levels, the protective effect of the eugenol was found to be augmented at both doses. This finding has corresponded to an increase in MDA, which was lowered by ethanol administration. Pre-treatment with eugenol on the ethanol-induced ulcer reduced the plasma NO levels and increased PGE2 along with a decreased TNF-α and IL-6 concentration. Additionally, significant transcriptional and translational upregulation of HSP70 and downregulation of iNOS were detected in the eugenol-treated rat stomach tissue.

CONCLUSION

Our findings demonstrated that eugenol had a considerable gastroprotective impact at low doses, which could be attributed to its ability to regulate inflammatory reactions and antioxidant capacity.

A preliminary evaluation of oxidative stress in patients with gastric cancer before chemotherapy

INTRODUCTION

Due to an imbalanced redox status, cancer cells generate intrinsically higher levels of reactive oxygen species (ROS) compared to normal cells. Targeting ROS is an important therapeutic strategy for cancer as exemplified by cancer drugs, which induce ROS-dependent synergistic cytotoxicity in gastric cancer cells. The present study was designed to assess the level of selected oxidative stress biomarkers in blood plasma derived from gastric cancer patients.

MATERIAL AND METHODS

The study assessed the oxidative/nitrative biomarkers in blood plasma isolated from 51 gastric (adenocarcinoma) cancer patients, compared to a control group of 32 healthy volunteers. Oxidative stress was evaluated using a panel of biomarkers such as plasma protein thiol groups and 3-nitrotyrosine levels as well as indicators of plasma lipid peroxidation, i.e. lipid hydroperoxides (LOOH) and thiobarbituric acid-reactive substances (TBARS). Additionally, the total antioxidant capacity of blood plasma (non-enzymatic capacity of blood plasma, NEAC) was also estimated.

RESULTS

Our results showed that patients with gastric cancer had significantly different levels of thiol groups (lower, p < 0.001) and 3-nitrotyrosine (higher, p < 0.0001), LOOH (higher, p < 0.05), TBARS (higher, p < 0.05), NEAC (lower, p < 0.0001), compared to the control group.

CONCLUSIONS

The present study indicates considerable oxidative/nitrative stress in gastric cancer patients. Our pilot study shows that not a single marker, but a biomarker panel, may be a more reliable representation of oxidative stress in patients with gastric cancer.

Gastroprotective and Antioxidative Effects of the Traditional Thai Polyherbal Formula Phy-Blica-D against Ethanol-Induced Gastric Ulcers in Rats

Phy-Blica-D is a traditional Thai polyherbal formula that has reduced oxidative stress in non-communicable diseases. However, evidence supporting the gastroprotective effects of Phy-Blica-D has not been previously reported. Therefore, this study aimed to evaluate the gastroprotective effects of Phy-Blica-D against gastric ulcers in rats and investigate the potential underlying mechanism. To estimate the possible mechanisms of action, we examined the levels of oxidative stress markers, such as reactive oxygen species (ROS) and malondialdehyde (MDA), as well as antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH). According to our results, rats treated with only 80% ethanol (vehicle group) exhibited significant increases in their ulcer area and ulcer index (UI). Moreover, the levels of ROS and MDA markedly increased in the vehicle group compared with the normal control group. Daily oral administration of Phy-Blica-D (500 and 1000 mg/kg) for 7 days not only significantly decreased the ulcer area and UI, but also remarkably decreased the ROS and MDA levels in gastric tissue. Gastric ulcers induced by ethanol had significantly decreased antioxidant enzyme activities (CAT and SOD) and non-enzymatic antioxidant (GSH), whereas pretreatment with Phy-Blica-D significantly improved the activities of CAT, SOD, and GSH. Moreover, after exposure to ethanol, the rats exhibited a significantly increased level of inducible nitric oxide synthase (iNOS), which was reduced after treatment with Phy-Blica-D. These findings suggest that Phy-Blica-D potentially exerts its gastroprotective effects by suppressing oxidative stress and stimulating antioxidant enzymes, which is one of the causes of destruction of cell membranes, and it is involved in the pathogenesis of acute gastric ulcers induced by ethanol.

Intraperitoneal Abscess as a Postoperative Complication of Gastric Endoscopic Submucosal Dissection

We herein report a case of intraperitoneal abscess as a postoperative complication of gastric endoscopic submucosal dissection (ESD). A 70-year-old man who underwent ESD for early gastric cancer sought consultation for abdominal pain on postoperative day 28. Abdominal computed tomography revealed intraperitoneal abscess rupture. He underwent image-guided laparoscopic irrigation. His postoperative course was favorable, and he was discharged after 27 days. Intraoperatively, a white plaque adhering to the gastric wall was surrounded by a large pus volume and suspected to be ESD-associated. We present this case with a literature review of the association between intraperitoneal abscess and ESD.

A role of connexin 43 on the drug-induced liver, kidney, and gastrointestinal tract toxicity with associated signaling pathways

Drug-induced organ toxicity/injury, especially in the liver, kidney, and gastrointestinal tract, is a systematic disorder that causes oxidative stress formation and inflammation resulting in cell death and organ failure. Current therapies target reactive oxygen species (ROS) scavenging and inhibit inflammatory factors in organ injury to restore the functions and temporary relief. Organ cell function and tissue homeostasis are maintained through gap junction intercellular communication, regulating connexin hemichannels. Mis-regulation of such connexin, especially connexin (Cx) 43, affects a comprehensive process, including cell differentiation, inflammation, and cell death. Aim to describe knowledge about the importance of connexin role and insights therapeutic targeting. Cx43 misregulation has been implicated in recent decades in various diseases. Moreover, in recent years there is increasing evidence that Cx43 is involved in the toxicity process, including hepatic, renal, and gastrointestinal disorders. Cx43 has the potential to initiate the immune system to cause cell death, which has been activated in the acceleration of apoptosis, necroptosis, and autophagy signaling pathway. So far, therapies targeting Cx43 have been under inspection and are subjected to clinical trial phases. This review elucidates the role of Cx43 in drug-induced vital organ injury, and recent reports compromise its function in the major signaling pathways.

Proteomics signature of autoimmune atrophic gastritis: towards a link with gastric cancer

BACKGROUND

Autoimmune atrophic gastritis (AAG) is a chronic disease that can progress to gastric cancer (GC). To better understand AAG pathology, this proteomics study investigated gastric proteins whose expression levels are altered in this disease and also in GC.

METHODS

Using two-dimensional difference gel electrophoresis (2D-DIGE), we compared protein maps of gastric corpus biopsies from AAG patients and controls. Differentially abundant spots (|fold change|≥ 1.5, P < 0.01) were selected and identified by LC-MS/MS. The spots were further assessed in gastric antrum biopsies from AAG patients (without and with Helicobacter pylori infection) and from GC patients and unaffected first-degree relatives of GC patients.

RESULTS

2D-DIGE identified 67 differentially abundant spots, with 28 more and 39 less abundant in AAG-corpus than controls. LC-MS/MS identified these as 53 distinct proteins. The most significant (adjusted P < 0.01) biological process associated with the less abundant proteins was "tricarboxylic acid cycle". Of the 67 spots, 57 were similarly differentially abundant in AAG-antrum biopsies irrespective of H. pylori infection status. The differential abundance was also observed in GC biopsies for 14 of 28 more abundant and 35 of 39 less abundant spots, and in normal gastric biopsies of relatives of GC patients for 6 and 25 spots, respectively. Immunoblotting confirmed the different expression levels of two more abundant proteins (PDIA3, GSTP gene products) and four less abundant proteins (ATP5F1A, PGA3, SDHB, PGC).

CONCLUSION

This study identified a proteomics signature of AAG. Many differential proteins were shared by GC and may be involved in the progression of AAG to GC.

Antioxidant-Rich Diet, GSTP1 rs1871042 Polymorphism, and Gastric Cancer Risk in a Hospital-Based Case-Control Study

Background

Chronic gastritis along with Helicobacter pylori (H. pylori) infection has been implicated in inflammatory response-related genes linked to the causation of gastric cancer. Glutathione S-transferase Pi (GSTP1) plays a role in regulating oxidative stress and detoxification against carcinogenesis. In this study, we aimed to determine whether an antioxidant-rich diet is associated with gastric cancer risk and identify how this association could be altered by GSTP1 genetic variants.

Methods

This study included 1,245 participants (415 cases and 830 controls) matched for age and sex. The dietary antioxidant capacity was estimated based on the oxygen radical absorbance capacity (ORAC) incorporated with a semiquantitative food frequency questionnaire. Five single nucleotide polymorphisms (SNPs) of GSTP1 (rs1695, rs749174, rs1871042, rs4891, and rs947895) were selected among the exome array genotype data.

Results

High dietary ORAC was inversely associated with gastric cancer (hydrophilic ORAC OR _{T3vs. T1}, 95% CI = 0.57, 0.39–0.82, P = 0.004; lipophilic ORAC = 0.66, 0.45–0.95, P = 0.021; total phenolics = 0.57, 0.39–0.83, P = 0.005). The polymorphism rs1871042 increased the risk of gastric cancer (OR, 95% CI = 1.55, 1.10–2.16, P = 0.01, CT+TT vs. CC). A remarkably reduced risk of gastric cancer was observed among those who had a high dietary ORAC according to rs1871042 polymorphism (hydrophilic ORAC OR _{T3vs. T1}, 95% CI = 0.36, 0.17–0.78, P for trend = 0.013; lipophilic ORAC = 0.58, 0.37–0.93, P for trend = 0.021; total phenolics = 0.38, 0.17–0.83, P for trend = 0.019).

Conclusions

Our findings indicate that dietary ORAC intake may be inversely associated with the risk of gastric cancer altered by genetic variants of GSTP1, providing new intervention strategies for gastric cancer patients.

The simplified Kyoto classification score is consistent with the ABC method of classification as a grading system for endoscopic gastritis

The ABC method combined with Helicobacter pylori antibody and serum pepsinogen is a useful predictive method for stomach cancer. Kyoto classification is a new grading system for endoscopic gastritis. However, the consistency of the Kyoto score with the ABC method remains unclear. The Kyoto classification score, which ranges from 0 to 8, is based on the following findings: atrophy, intestinal metaplasia, diffuse redness, nodularity, and enlarged folds. Furthermore, we defined a simplified Kyoto classification score as the sum of scores of just atrophy and intestinal metaplasia. The association between the Kyoto classification score and the ABC method was analyzed using the Kruskal-Wallis and Steel-Dwass tests. A total of 307 subjects were enrolled. Kyoto classification scores were similar in groups B, C, and D, while scores in group A were significantly lower than those of the other groups. The simplified Kyoto classification score showed the same stepwise increase as the classification of the ABC method. In conclusion, unlike the Kyoto classification score, the simplified Kyoto score showed the same significant stepwise increase as the classification of the ABC method.

Brassica oleracea Prevents HCl/Ethanol-Induced Gastric Damages in Mice

Brassica oleracea var. capitata L. (cabbage) is a popular vegetable with a wide range of pharmacological activities that help to promote human health. The present study investigated the beneficial effects of B. oleracea var. capitata L. extract (BOE) on HCl/ethanol (H/E)-induced gastric damages in mice. Pre-administration of BOE (25–100 mg/kg) for 7 consecutive days significantly decreased macroscopically visible lesion on the gastric mucosa induced by H/E. In addition, results from hematoxylin and eosin-stained gastric tissue showed that BOE inhibited invaded percentage of lesion and prevented the reduction in mucosal thickness in peri-ulcerative region. BOE significantly alleviated the H/E-mediated decreases in Alcian blue binding, total hexose, sialic acid, and collagen in the gastric tissue, suggesting BOE attenuates the gastric damage via preserving the integrity of gastric mucus. Moreover, BOE significantly decreased histamine level in the plasma and reduced mRNA levels associated with secreting gastric acid. Furthermore, BOE inhibited myeloperoxidase activity and suppressed nuclear factor-κB mRNA and its dependent inflammatory genes expression induced by H/E. BOE also strengthened antioxidant enzyme activity, with a mitigating H/E-mediated increase in malondialdehyde level of the gastric tissue. Thus, these results suggest that BOE has the potential to protect the gastric tissue via inhibiting gastric acid secretion, inflammation, and oxidative stress.

Circulating Irisin Levels and Redox Status Markers in Patients with Gastric Cancer: A Case-Control Study

OBJECTIVE

Irisin, mostly known as an exercise-induced fat browning myokine, has been recently detected in several cancer cells, and its potential for being utilized as a biomarker for early diagnosis of some cancers, such as Gastric cancer (GC), is the subject of speculation. The present study aims to compare serum irisin levels in GC patients and healthy controls and assess the interrelation between irisin and oxidative stress markers.

METHODS

In this case-control study, 22 newly diagnosed GC patients and 29 healthy controls were recruited based on the inclusion criteria. Serum levels of irisin were quantified in duplicates by ELISA. Oxidative stress indices, including total antioxidant power in sera, thiol group, malondialdehyde, and superoxide dismutase concentrations, were also measured in both groups. An independent-sample t-test was used to compare the means between the two studied groups.

RESULTS

Serum levels of irisin were significantly higher in the GC group compared with those of their healthy counterparts (p =0.032). No significant differences were observed between the two groups in terms of the serum total antioxidant power or the oxidative stress marker, including MDA, thiol groups, and SOD concentration in sera. Furthermore, there was no significant association between irisin, FRAP, the Thiol group, and the SOD activity.

CONCLUSION

According to the finding, the increased serum levels of irisin in GC patients can play a potential role in the early diagnosis of the GC patients; hence, this peptide can be employed as a new diagnostic indicator of GC.
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A Quantitative Proteome Map of the Human Body

Determining protein levels in each tissue and how they compare with RNA levels is important for understanding human biology and disease as well as regulatory processes that control protein levels. We quantified the relative protein levels from over 12,000 genes across 32 normal human tissues. Tissue-specific or tissue-enriched proteins were identified and compared to transcriptome data. Many ubiquitous transcripts are found to encode tissue-specific proteins. Discordance of RNA and protein enrichment revealed potential sites of synthesis and action of secreted proteins. The tissue-specific distribution of proteins also provides an in-depth view of complex biological events that require the interplay of multiple tissues. Most importantly, our study demonstrated that protein tissue-enrichment information can explain phenotypes of genetic diseases, which cannot be obtained by transcript information alone. Overall, our results demonstrate how understanding protein levels can provide insights into regulation, secretome, metabolism, and human diseases.

Individual and synergistic protective properties of Salvia officinalis decoction extract and sulfasalazine against ethanol-induced gastric and small bowel injuries

The present study was carried out to determine the phytochemical composition of Salvia officinalis flowers decoction extract (SOFDE) as well as its individual and/or synergistic actions with sulfasalazine against ethanol (EtOH)-induced peptic ulcer in Wistar rats. In this respect, rats were divided into six groups of eight animals each: control, EtOH, EtOH + sulfasalazine (SULF, 100 mg kg^-1, b.w., p.o.), mixture: MIX (SOFDE, 50 mg kg^-1 b.w., p.o. + SULF, 50 mg kg^-1, b.w., p.o.) and EtOH + two doses of SOFDE (100 and 200 mg kg^-1 b.w., p.o.). In vitro, the phytochemical and the antioxidant properties were determined using colorimetric analysis. HPLC-PDA/ESI-MS assay was used to identify the distinctive qualitative profile of phenolic compounds. Our results firstly indicated that SOFDE is rich in total tannins, flavonols, anthocyanins and a moderate concentration of total carotenoids. Chromatographic techniques allowed the identification of 13 phenolic compounds and the major ones are quinic acid, protocatechuic acid, gallic acid and salviolinic acid. SOFDE also exhibited an important in vitro antioxidant activity using the β-carotene bleaching method. In vivo, SOFDE and the mixture provide significant protection against ethanol-induced gastric and duodenal macroscopic and histological alterations. Also, SOFDE alone or in combination with SULF, showed a significant protection against the secretory profile disturbances, lipid peroxidation, antioxidant enzyme activities and non-enzymatic antioxidant level depletion induced by alcohol administration. Importantly, we showed that EtOH acute intoxication increased gastric and intestinal calcium, free iron, magnesium and hydrogen peroxide (H₂O₂) levels, while SOFDE/MIX treatment protected against all these intracellular mediators' deregulation. We also showed that alcohol treatment significantly increased the C-reactive protein (CRP) and alkaline phosphatase (ALP) activities in plasma. The SOFDE and MIX treatment significantly protected against alcohol-induced inflammation. More importantly, we showed in the present work that the mixture exerted a more important effect than SOFDE and SULF each alone indicating a possible synergism between these two molecules. In conclusion, our data suggests that SOFDE and SULF exerted a potential synergistic protective effect against all the macroscopic, histological and biochemical disturbances induced by EtOH intoxication. This protection might be related in part to its antioxidant and anti-inflammatory properties as well as by negatively regulating Fenton reaction components such as H₂O₂ and free iron.

Effects of transport stress on pathological injury and expression of main heat shock proteins in the caprine stomach

Background

Transportation is necessary to introduce new breeds of goats to the farm and move the adult meat goat from the farm to the slaughterhouse. However, these actions may give rise to transport stress. Heat shock proteins (HSPs) are playing some important regulate roles during transport stress. The aim of this study was to evaluate the effects of transport stress on the pathological injury and HSPs expression in the stomach of goats. A total of three batches of Ganxi goats from western Jiangxi province were enrolled in this study. For each batch, twelve healthy adult male goats were randomly divided into three groups (four goats per batch and per group): Control group, stress group transported during 2 h and stress group transported during 6 h.

Results

Our results showed that the different degrees of stomach walls damage, with the change of expression levels of heat shock protein 27 (HSP27), heat shock protein 70 (HSP70) and heat shock protein 90 (HSP90), occurred after goats transportation. In rumen, the mRNA and protein expressions of HSP27 and HSP70 were increased after transport stress, but not HSP90. In reticulum, all three HSPs mRNA and protein levels were upregulated after 2 h transport, but decreased after 6 h transport. In omasum, HSP27 and HSP70 mRNA and protein were increased after transport stress, however, HSP90 mRNA level only had a slightly enhancement after transport stress. In abomasum, HSP70 and HSP90 mRNA and protein levels were increased after transport stress, but HSP27 was decreased after transport stress.

Conclusions

Taken together, these results revealed that the pathological changes in the gastric tissues and the stomach HSPs expression in goats are related to transport stress and duration. Moreover, this study also provides some new data to advocate reducing transport stress of goats and improving animal welfare.

Clinical features of cardiac nodularity-like appearance induced by Helicobacter pylori infection

BACKGROUND

We have previously reported that Helicobacter pylori (H. pylori)-associated nodular gastritis could occur in both the antrum and the cardia. Cardiac nodularity-like appearance (hereafter, called as cardiac nodularity) had a high predictive accuracy for the diagnosis of H. pylori infection. In the previous study, we included only the patients who were evaluated for H. pylori infection for the first time, and excluded patients with a history of eradication. Therefore, the prevalence and clinical features of cardiac nodularity remains unknown.

AIM

To perform this cross-sectional study to explore the characteristics of cardiac nodularity.

METHODS

Consecutive patients who underwent esophagogastroduodenoscopy between May, 2017 and August, 2019 in the Toyoshima Endoscopy Clinic were enrolled in this study. We included H. pylori-negative, H. pylori-positive, and H. pylori-eradicated patients, and excluded patients with unclear H. pylori status and eradication failure. H. pylori infection was diagnosed according to serum anti-H. pylori antibody and the urea breath test or histology. Cardiac nodularity was defined as a miliary nodular appearance or the presence of scattered whitish circular small colorations within 2 cm of the esophagogastric junction. Nodularity was visualized as whitish in the narrow-band imaging mode. We collected data on the patients' baseline characteristics.

RESULTS

A total of 1078 patients were finally included. Among H. pylori-negative patients, cardiac nodularity and antral nodularity were recognized in 0.14% each. Among H. pylori-positive patients, cardiac nodularity and antral nodularity were recognized in 54.5% and 29.5%, respectively. Among H. pylori-eradicated patients, cardiac nodularity and antral nodularity were recognized in 4.5% and 0.6%, respectively. The frequency of cardiac nodularity was significantly higher than that of antral nodularity in H. pylori-positive and -eradicated patients. The frequencies of cardiac nodularity and antral nodularity in H. pylori-eradicated patients were significantly lower than those in H. pylori-positive patients (P < 0.001). The patients with cardiac nodularity were significantly younger than those without cardiac nodularity (P = 0.0013). Intestinal metaplasia score of the patients with cardiac nodularity were significantly lower than those without cardiac nodularity (P = 0.0216). Among H. pylori-eradicated patients, the patients with cardiac nodularity underwent eradication significantly more recently compared with those without cardiac nodularity (P < 0.0001).

CONCLUSION

This report outlines the prevalence and clinical features of cardiac nodularity, and confirm its close association with active H. pylori infection.

Trefoil Factor Family (TFF) Peptides and Their Diverse Molecular Functions in Mucus Barrier Protection and More: Changing the Paradigm

Trefoil factor family peptides (TFF1, TFF2, TFF3) are typically co-secreted together with mucins. Tff1 represents a gastric tumor suppressor gene in mice. TFFs are also synthesized in minute amounts in the immune and central nervous systems. In mucous epithelia, they support rapid repair by enhancing cell migration ("restitution") via their weak chemotactic and anti-apoptotic effects. For a long time, as a paradigm, this was considered as their major biological function. Within recent years, the formation of disulfide-linked heterodimers was documented for TFF1 and TFF3, e.g., with gastrokine-2 and IgG Fc binding protein (FCGBP). Furthermore, lectin activities were recognized as enabling binding to a lipopolysaccharide of Helicobacter pylori (TFF1, TFF3) or to a carbohydrate moiety of the mucin MUC6 (TFF2). Only recently, gastric TFF1 was demonstrated to occur predominantly in monomeric forms with an unusual free thiol group. Thus, a new picture emerged, pointing to diverse molecular functions for TFFs. Monomeric TFF1 might protect the gastric mucosa as a scavenger for extracellular reactive oxygen/nitrogen species. Whereas, the TFF2/MUC6 complex stabilizes the inner layer of the gastric mucus. In contrast, the TFF3-FCGBP heterodimer (and also TFF1-FCGBP) are likely part of the innate immune defense of mucous epithelia, preventing the infiltration of microorganisms.

Nodularity-like appearance in the cardia: novel endoscopic findings for Helicobacter pylori infection

Background and study aims   Helicobacter pylori -associated nodular gastritis, which is associated with follicular lymphoid hyperplasia, is mainly recognized in the antrum. However, we have also observed nodularity-like appearance in the cardia. This study aimed to investigate the clinical significance of cardiac nodularity-like appearance in H. pylori -associated gastritis. Patients and methods  Patients who underwent esophagogastroduodenoscopy and were evaluated for H. pylori infection for the first time were enrolled. A nodularity-like appearance in the cardia was defined as a miliary nodular appearance or scattered appearances of small circular whitish coloration. H. pylori infection was diagnosed according to serum anti- H. pylori antibody and the urea breath test or histology. Accuracy of the H. pylori infection diagnoses based on nodularity-like appearance were assessed. Results  Among 265 patients, 42 patients (15.8 %) were diagnosed as positive for H. pylori . Cardiac nodularity-like appearance and antral nodularity were recognized in 25 and 15 patients, respectively. In accuracy of predicting H. pylori by cardiac nodularity-like appearance, specificity was 0.996, sensitivity was 0.571, positive predictive value was 0.960, negative predictive value was 0.925, and accuracy was 0.928. The sensitivity of cardiac nodularity-like appearance was significantly higher than that of antral nodularity ( P  = 0.0284). Conclusions  Cardiac nodularity-like appearance had a high accuracy rate for H. pylori infection diagnosis. Cardiac nodularity-like appearance was found more frequently than antral nodularity.

Carbon Monoxide Being Hydrogen Sulfide and Nitric Oxide Molecular Sibling, as Endogenous and Exogenous Modulator of Oxidative Stress and Antioxidative Mechanisms in the Digestive System

Oxidative stress reflects an imbalance between oxidants and antioxidants in favor of the oxidants capable of evoking tissue damage. Like hydrogen sulfide (H2S) and nitric oxide (NO), carbon monoxide (CO) is an endogenous gaseous mediator recently implicated in the physiology of the gastrointestinal (GI) tract. CO is produced in mammalian tissues as a byproduct of heme degradation catalyzed by the heme oxygenase (HO) enzymes. Among the three enzymatic isoforms, heme oxygenase-1 (HO-1) is induced under conditions of oxidative stress or tissue injury and plays a beneficial role in the mechanism of protection against inflammation, ischemia/reperfusion (I/R), and many other injuries. According to recently published data, increased endogenous CO production by inducible HO-1, its delivery by novel pharmacological CO-releasing agents, or even the direct inhalation of CO has been considered a promising alternative in future experimental and clinical therapies against various GI disorders. However, the exact mechanisms underlying behind these CO-mediated beneficial actions are not fully explained and experimental as well as clinical studies on the mechanism of CO-induced protection are awaited. For instance, in a variety of experimental models related to gastric mucosal damage, HO-1/CO pathway and CO-releasing agents seem to prevent gastric damage mainly by reduction of lipid peroxidation and/or increased level of enzymatic antioxidants, such as superoxide dismutase (SOD) or glutathione peroxidase (GPx). Many studies have also revealed that HO-1/CO can serve as a potential defensive pathway against oxidative stress observed in the liver and pancreas. Moreover, increased CO levels after treatment with CO donors have been reported to protect the gut against formation of acute GI lesions mainly by the regulation of reactive oxygen species (ROS) production and the antioxidative activity. In this review, we focused on the role of H2S and NO molecular sibling, CO/HO pathway, and therapeutic potential of CO-releasing pharmacological tools in the regulation of oxidative stress-induced damage within the GI tract with a special emphasis on the esophagus, stomach, and intestines and also two solid and important metabolic abdominal organs, the liver and pancreas.

Comparison of Antioxidant Effects of the Proton Pump-Inhibiting Drugs Omeprazole, Esomeprazole, Lansoprazole, Pantoprazole, and Rabeprazole

INTRODUCTION

Peptic lesions usually develop when there is an imbalance between aggressive drivers and gastro-protective mediators that guard the lining of the gastrointestinal tract. The most crucial of these mediators are antioxidants, whose loss may predispose to oxidative stress, which is believed to be the main aggravator of several diseases including peptic ulcer. Proton pump inhibitors (PPIs) are drugs that are highly effective and widely used for therapeutic management of peptic disorders through inhibition of gastric acid secretion. In spite of this, oxidative damage may continue to be a major issue that can predispose to future lesions.

OBJECTIVE

The present study is designed to explore the possible antioxidant capability of different PPIs, including omeprazole, esomeprazole, lansoprazole, pantoprazole, and rabeprazole, in an aim to suggest an agent that, in addition to its acid-suppression properties, can provide antioxidant profit.

METHODS

The antioxidant activity of different PPIs was evaluated calorimetrically to test the ability of each drug to quench oxygen free radical, using the well-known stable free radical α,α-diphenyl-β-picrylhydrazyl (DPPH), and compared to ascorbic acid (AA; vitamin C). The measurements were performed using a spectrophotometer at 517 nm.

RESULTS

All the studied drugs reduced DPPH, but to different extents. However, omeprazole and esomeprazole showed the highest ability to scavenge free radicals (50% inhibitory concentrations [IC50s] of the percentage for free radical scavenging activity are 18.7 ± 5.7 and 18.7 ± 5.7, respectively, and the AA equivalents are 83,772 ± 11,887 and 81,732 ± 8,523 mg AA/100 g, respectively). Conversely, lansoprazole, pantoprazole, and rabeprazole might be having no role in this story (IC50s of the percentage for free radical scavenging activity are 49.3 ± 3.1, 49 ± 9.4, and 40.7 ± 7.2, respectively, and the AA equivalents are 30,458 ± 3,884, 32,222 ± 10,377, and 37,876 ± 8,816 mg AA/100 g, respectively).

CONCLUSION

Thus, omeprazole and esomeprazole may confer a significant dual action in gastrointestinal protection by providing potent antioxidant properties in addition to their major role as acid-suppression agents. However, further studies are essential to elucidate the mechanism behind the difference between the drugs of the same class.

Malabaricone C Attenuates Nonsteroidal Anti-Inflammatory Drug-Induced Gastric Ulceration by Decreasing Oxidative/Nitrative Stress and Inflammation and Promoting Angiogenic Autohealing

Aims: Nonsteroidal anti-inflammatory drugs (NSAIDs), among the most commonly used drugs worldwide, are associated with gastrointestinal (GI) complications that severely limit the clinical utility of this essential class of pain medications. Here, we mechanistically dissect the protective impact of a natural product, malabaricone C (Mal C), on NSAID-induced gastropathy. Results: Mal C dose dependently diminished erosion of the stomach lining and inflammation in mice treated with NSAIDs with the protective impact translating to improvement in survival. By decreasing oxidative and nitrative stress, Mal C treatment prevented NSAID-induced mitochondrial dysfunction and cell death; nuclear factor κ-light-chain enhancer of activated B cell induction, release of proinflammatory cytokines and neutrophil infiltration; and disruptions in the vascular endothelial growth factor/endostatin balance that contributes to mucosal autohealing. Importantly, Mal C failed to impact the therapeutic anti-inflammatory properties of multiple NSAIDs in a model of acute inflammation. In all assays tested, Mal C proved as or more efficacious than the current first-line therapy for NSAID-dependent GI complications, the proton pump inhibitor omeprazole. Innovation: Given that omeprazole-mediated prophylaxis is, itself, associated with a shift in NSAID-driven GI complications from the upper GI to the lower GI system, there is a clear and present need for novel therapeutics aimed at ameliorating NSAID-induced gastropathy. Mal C provided significant protection against NSAID-induced gastric ulcerations impacting multiple critical signaling cascades contributing to inflammation, cell loss, extracellular matrix degradation, and angiogenic autohealing. Conclusion: Thus, Mal C represents a viable lead compound for the development of novel gastroprotective agents.

The Tumor Suppressor TFF1 Occurs in Different Forms and Interacts with Multiple Partners in the Human Gastric Mucus Barrier: Indications for Diverse Protective Functions

TFF1 is a protective peptide of the Trefoil Factor Family (TFF), which is co-secreted with the mucin MUC5AC, gastrokine 2 (GKN2), and IgG Fc binding protein (FCGBP) from gastric surface mucous cells. Tff1-deficient mice obligatorily develop antropyloric adenoma and about 30% progress to carcinomas, indicating that Tff1 is a tumor suppressor. As a hallmark, TFF1 contains seven cysteine residues with three disulfide bonds stabilizing the conserved TFF domain. Here, we systematically investigated the molecular forms of TFF1 in the human gastric mucosa. TFF1 mainly occurs in an unusual monomeric form, but also as a homodimer. Furthermore, minor amounts of TFF1 form heterodimers with GKN2, FCGBP, and an unknown partner protein, respectively. TFF1 also binds to the mucin MUC6 in vitro, as shown by overlay assays with synthetic ¹²⁵I-labeled TFF1 homodimer. The dominant presence of a monomeric form with a free thiol group at Cys-58 is in agreement with previous studies in Xenopus laevis and mouse. Cys-58 is likely highly reactive due to flanking acid residues (PPEEEC⁵⁸EF) and might act as a scavenger for extracellular reactive oxygen/nitrogen species protecting the gastric mucosa from damage by oxidative stress, e.g., H₂O₂ generated by dual oxidase (DUOX).