Protective Factors of the Gastric and Duodenal Mucosa: An Overview

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.

Neuropeptide W facilitates chronic gastric ulcer healing by the regulation of cyclooxygenase and NF-κB signaling pathways

AIMS

Putative beneficial effects of neuropeptide W (NPW) in the early phase of gastric ulcer healing process and the involvement of cyclooxygenase (COX) enzymes were investigated in an acetic acid-induced gastric ulcer model.

MAIN METHODS

In anesthetized male Sprague-Dawley rats, acetic acid was applied surgically on the serosa and then a COX-inhibitor (COX-2-selective NS-398, COX-1-selective ketorolac, or non-selective indomethacin; 2 mg/kg/day, 3 mg/kg/day or 5 mg/kg/day; respectively) or saline was injected intraperitoneally. One h after ulcer induction, omeprazole (20 mg/kg/day), NPW (0.1 μg/kg/day) or saline was intraperitoneally administered. Injections of NPW, COX-inhibitors, omeprazole or saline were continued for the following 2 days until rats were decapitated at the end of the third day.

KEY FINDINGS

NPW treatment depressed gastric prostaglandin (PG) I2 level, but not PGE2 level. Similar to omeprazole, NPW treatment significantly reduced gastric and serum tumor necrosis factor-alpha and interleukin-1 beta levels and depressed the upregulation of nuclear factor kappa B (NF-κB) and COX-2 expressions due to ulcer. In parallel with the histopathological findings, treatment with NPW suppressed ulcer-induced increases in myeloperoxidase activity and malondialdehyde level and replenished glutathione level. However, the inhibitory effect of NPW on myeloperoxidase activity and NPW-induced increase in glutathione were not observed in the presence of COX-1 inhibitor ketorolac or the non-selective COX-inhibitor indomethacin.

SIGNIFICANCE

In conclusion, NPW facilitated the healing of gastric injury in rats via the inhibition of pro-inflammatory cytokine production, oxidative stress and neutrophil infiltration as well as the downregulation of COX-2 protein and NF-κB gene expressions.

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.

Tormentic acid, a triterpenoid isolated from the fruits of Chaenomeles speciose, protected indomethacin-induced gastric mucosal lesion via modulating miR-139 and the CXCR4/CXCL12/PLC/PKC/Rho a/MLC pathway

CONTEXT

Tormentic acid (TA), an effective triterpenoid isolated from Chaenomeles speciosa (Sweet) Nakai (Rosaceae) fruits, exerts an effective treatment for gastric damage.

OBJECTIVE

To investigate the gastroprotective effect of TA on indomethacin (IND) damaged GES-1 cells and rats, and explore potential mechanisms.

MATERIALS AND METHODS

TA concentrations of 1.563-25 µM were used. Cell proliferation, apoptosis and migration were performed using MTT, colony formation, wound healing, migration, Hoechst staining assays. SD rats were divided into control, IND, TA (1, 2 and 4 mg/kg) + IND groups, once a day for 21 continuous days. Twenty-four hours after the last administration, all groups except the control group were given IND (100 mg/kg) by gavage. Gastric juice parameters, gastric ulcer, gastric blood flow (GBF), blood biochemical parameters and cytokine analysis and gastric mucosal histopathology were detected for 2 h and 6 h after IND oral administration. The mRNA and protein expression of miR-139 and the CXCR4/CXCL12/PLC/PKC/Rho A/MLC pathway were analyzed in the IND-damaged GES-1 cells and gastric tissue of rats.

RESULTS

TA might ameliorate the gastric mucosal injury by accelerating the IND-damaged GES-1 cell proliferation and migration, ameliorating GBF, ulcer area and pathologic changes, the redox system and cytokine levels, the gastric juice parameters, elevating the gastric pH in IND damaged rats; suppressed miR-139 mRNA expression, elevated CXCR4 and CXCL12 mRNA and protein expression, p-PLC, p-PKC, Rho A, MLCK and p-MLC protein expression.

DISCUSSION AND CONCLUSIONS

TA may have potential use as a clinical drug candidate for gastric mucosal lesion treatment.

Gastroprotective effect of Artemisia absinthium L.: A medicinal plant used in the treatment of digestive disorders

ETHNOPHARMACOLOGICAL RELEVANCE

Wormwood (Artemisia absinthium L.) is traditionally used for stomach pain and gastric relief. However, its possible gastroprotective effect has not yet been experimentally evaluated.

AIM OF THE STUDY

This study evaluated the gastroprotective effect of aqueous extracts obtained through hot and room temperature maceration of A. absinthium aerial parts in rats.

MATERIALS AND METHODS

The gastroprotective effect of hot aqueous extract (HAE) and room temperature aqueous extract (RTAE) from A. absinthium aerial parts were evaluated in rats using a model of acute gastric ulcer induced by ethanol p.a. The stomachs were collected to measure the gastric lesion area and histological and biochemical analysis. UHPLC-HRMS/MS analysis was used to determine the chemical profile of the extracts.

RESULTS

Eight main peaks in the UHPLC chromatogram were identified in both HAE and RTAE extracts: tuberonic acid glycoside (1), rupicolin (2), 2-hydroxyeupatolide (3), yangabin (4), sesartemin (5), artemetin (6), isoalantodiene (7), and dehydroartemorin (8). For RTAE, a higher diversity of sesquiterpene lactones was observed. The groups treated with RTAE at 3%, 10%, and 30% presented a gastroprotective effect, reducing the lesion area by 64.68%, 53.71%, and 90.04%, respectively, when compared with the vehicle (VEH)-treated group. On the other hand, the groups treated with HAE at 3%, 10%, and 30% presented values of lesion areas higher than those of the VEH group. Changes in the submucosa layer, inflammatory process with edema, cellular infiltration, and mucin depletion were detected in the gastric mucosa exposed to ethanol, which was fully prevented by RTAE treatment. Neither HAE nor RTAE could increase the reduced glutathione levels in the injured gastric tissue, but RTAE (30%) reduced the formation of lipid hydroperoxides. When the rats were pre-treated with NEM (a chelator of non-protein thiols) or L-NAME (non-selective nitric oxide synthase inhibitor), the RTAE lost the ability to protect the gastric mucosa.

CONCLUSIONS

This study corroborates the ethnopharmacological use of this specie to treat gastric disorders revealing the gastroprotective effect of the room-temperature aqueous extract of A. absinthium aerial parts. Its mode of action may involve the ability of the infusion to maintain the gastric mucosal barrier integrity.

Antiulcer mechanisms of the hydroalcoholic extract from Aztec marigolds' medicinal and edible flowers (Tagetes erecta L.)

The antiulcer mechanisms of the dry extract of T. erecta flowers (DETe) were studied here. The acute ulcers induced by acidified ethanol or indomethacin were reproduced in mice pretreated with DETe (3 - 300 mg/kg). The antiulcer activity of DETe was also verified in mice pretreated with NEM, L-NAME, indomethacin, or yohimbine. The antisecretory effect of DETe was verified in rats, and its anti-Helicobacter pylori activity was determined in vitro. DETe (300 mg/kg, p.o) reduced the ethanol- or indomethacin-induced ulcer by 49 and 93%, respectively. The pre-treatment with L-NAME, NEM or yohimbine abolished the gastroprotective effect of DETe. However, DETe did not change the volume, acidity, or peptic activity in rats and did not affect H. pylori. This study expands knowledge about the antiulcerogenic potential of DETe, evidencing the role of nitric oxide, non-protein sulfhydryl groups, α2 adrenergic receptors, and prostaglandins, but not antisecretory or anti-H. pylori properties.

Evaluation of the gastroprotective and ulcer healing properties by Fridericia chica (Bonpl.) L.G. Lohmann hydroethanolic extract of leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Fridericia chica (Bonpl.) L.G. Lohmann (Bignoniaceae), is a climber native to Brazil, found in all Brazilian biomes. It is mostly known in Brazil as "carajiru," and home medicines made from the leaves have been used to cure disorders including stomach ulcers and other gastrointestinal disorders.

AIM OF THE STUDY

The objective of the study was to investigate the F. chica hydroethanolic extract of leaves (HEFc) preventative and curative antiulcer gastrointestinal efficacy as well as the mechanisms of action using in vivo rodent models.

MATERIALS AND METHODS

F. chica was collected in the municipality of Juína, Mato Grosso, and its leaves were used to prepare the extract by maceration technique (70% hydroethanol in the 1:10 ratio, w/v) to obtain the HEFc. The chromatographic analysis of HEFc was carried out by High Performance Liquid Chromatography-Photo Diode Array-Electrospray Ionization-Mass Spectrometry (HPLC-PDA-ESI-MS)- LCQ Fleet™ system. To determine the potential antiulcer potential of HEFc (1, 5 and 20 mg/kg, p.o.), the gastroprotective activity was assessed in various animal models of stomach ulcers caused by acidified ethanol, water constraint stress, indomethacin, (acute), and acid acetic (chronic). Additionally, the prokinetic properties of the HEFC were assessed in mice. The gastroprotective underlying mechanisms were evaluated by the histopathological analysis and determination of gastric secretion (volume, free and total acidity), gastric barrier mucus, activation of PGs, NO, K ⁺_ATP channels, α₂-adrenoceptor, antioxidant activity (GSH, MPO and MDA), NO and mucosal cytokines (TNF-α, IL-1β, and IL-10) levels.

RESULTS

The chemical composition of HEFc was analyzed and apigenin, scutellarin, and carajurone were identified. HEFc (1, 5 and 20 mg/kg) showed effect against acute ulcers induced by HCl/EtOH with a reduction in the ulcerated area of 64.41% (p < 0.001), 54.23% (p < 0.01), 38.71% (p < 0.01), respectively. In the indomethacin experiment, there was no change in the doses tested, whereas in the water immersion restraint stress ulcer there was a reduction of lesions at doses of 1, 5, and 20 mg/kg by 80.34% (p < 0.001), 68.46% (p < 0.01) and 52.04% (p < 0.01). HEFc increased the mucus production at doses of 1 and 20 mg/kg in 28.14% (p < 0.05) and 38.36% (p < 0.01), respectively. In the pyloric ligation-induced model of gastric ulceration, the HEFc decreased the total acidity in all doses by 54.23%, 65.08%, and 44.40% (p < 0.05) and gastric secretory volume in 38.47% at dose of 1 mg/kg (p < 0,05) and increased the free acidity at the dose of 5 mg/kg by 11.86% (p < 0.05). The administration of EHFc (1 mg/kg) showed a gastroprotective effect possibly by stimulating the release of prostaglandins and activating K⁺_ATP channels and α_2-adrenoreceptors. Also, the gastroprotective effect of HEFc involved an increase in CAT and GSH activities, and a reduction in MPO activity and MDA levels. In the chronic gastric ulcer model, the HEFc (1, 5 and 20 mg/kg) decreased the ulcerated area significantly (p < 0.001) at all doses by 71.37%, 91.00%, and 93.46%, respectively. In the histological analysis, HEFc promoted the healing of gastric lesions by stimulating the formation of granulation tissue and consequently epithelialization. On the other hand, regarding the effect of HEFc on gastric emptying and intestinal transit, it was observed that the extract did not alter gastric emptying, but there was an increase in intestinal transit at the dose of 1 mg/kg (p < 0.01).

CONCLUSION

These outcomes confirmed the advantages of Fridericia chica leaves for the treatment of stomach ulcers, which are well-known. HEFc was discovered to have antiulcer characteristics through multitarget pathways, which might be related to an increase in stomach defense mechanisms and a decrease in defensive factor. HEFc can be regarded as a potential new antiulcer herbal remedy because of its antiulcer properties, which may be attributed to the mixture of flavonoids, apigenin, scutellarin and carajurone.

A novel nano-formulation of olmesartan medoxomil with improved delivery and efficacy in the treatment of indomethacin-induced duodenitis in rats

There are few studies addressing duodenal inflammation. This study was designed to investigate the effects of a recently developed biotechnological product, a nano-formulation of olmesartan medoxomil (OM) - olmesartan medoxomil zeinmersomes (OMZ) - for the treatment of indomethacin-induced duodenitis in rats. Adult male Wistar rats were given indomethacin (10 mg/kg/day) for four weeks. They were divided into a positive control group (PC, untreated) and two groups treated orally with 3 mg/kg per day of OM or OMZ for the last two weeks of the 4-week indomethacin-treatment. At end of the four weeks, blood and duodenum were collected. Duodenal homogenate was used for measurement of levels of myeloperoxidase, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), malondialdehyde, reduced glutathione (GSH), and cleaved caspase-3. Duodenal sections were stained with H&E. Gene expressions of nuclear factor kappa B (NF-κB p65), Bcl-2-associated X protein (Bax), and B-cell lymphoma 2 (Bcl-2) by RT-PCR, and protein expression of survivin by western blot were assessed. Plasma and duodenal olmesartan concentrations were measured by high performance liquid chromatography mass spectrometry. The duodenitis rats showed significantly higher duodenal levels of myeloperoxidase, TNF-α, IL-6, malondialdehyde, and cleaved caspase-3, a significantly lower GSH level, and histopathological alterations. Moreover, they showed upregulated gene expressions of NF-κB p65 and Bax, downregulated gene expression of Bcl-2, decreased Bcl-2/Bax ratio, and lower protein expression of survivin. OMZ was more effective in protecting the duodenum from indomethacin-induced injuries compared to OM due to improved delivery, higher bioavailability, and better anti-inflammatory, antioxidant, and antiapoptotic effects. OMZ could be a better choice for hypertensive patients with non-steroidal anti-inflammatory drugs-induced duodenitis.

Hericium erinaceus, a medicinal fungus with a centuries-old history: Evidence in gastrointestinal diseases

Hericium erinaceus is an edible and medicinal mushroom commonly used in traditional Chinese medicine for centuries. Several studies have highlighted its therapeutic potential for gastrointestinal disorders such as gastritis and inflammatory bowel diseases. In addition, some components of this mushroom appear to possess strong antineoplastic capabilities against gastric and colorectal cancer. This review aims to analyse all available evidence on the digestive therapeutic potential of this fungus as well as the possible underlying molecular mechanisms.

Alteration of gastric microbiota and transcriptome in a rat with gastric intestinal metaplasia induced by deoxycholic acid

Objective

Bile reflux plays a key role in the development of gastric intestinal metaplasia (GIM), an independent risk factor of gastric cancer. Here, we aimed to explore the biological mechanism of GIM induced by bile reflux in a rat model.

Methods

Rats were treated with 2% sodium salicylate and allowed to freely drink 20 mmol/L sodium deoxycholate for 12 weeks, and GIM was confirmed by histopathological analysis. Gastric microbiota was profiled according to the 16S rDNA V3-V4 region, gastric transcriptome was sequenced, and serum bile acids (BAs) were analyzed by targeted metabolomics. Spearman's correlation analysis was used in constructing the network among gastric microbiota, serum BAs, and gene profiles. Real-time polymerase chain reaction (RT-PCR) measured the expression levels of nine genes in the gastric transcriptome.

Results

In the stomach, deoxycholic acid (DCA) decreased the microbial diversity but promoted the abundances of several bacterial genera, such as Limosilactobacillus, Burkholderia-Caballeronia-Paraburkholderia, and Rikenellaceae RC9 gut group. Gastric transcriptome showed that the genes enriched in gastric acid secretion were significantly downregulated, whereas the genes enriched in fat digestion and absorption were obviously upregulated in GIM rats. The GIM rats had four promoted serum BAs, namely cholic acid (CA), DCA, taurocholic acid, and taurodeoxycholic acid. Further correlation analysis showed that the Rikenellaceae RC9 gut group was significantly positively correlated with DCA and RGD1311575 (capping protein-inhibiting regulator of actin dynamics), and RGD1311575 was positively correlated with Fabp1 (fatty acid-binding protein, liver), a key gene involved in fat digestion and absorption. Finally, the upregulated expression of Dgat1 (diacylglycerol acyltransferase 1) and Fabp1 related to fat digestion and absorption was identified by RT-PCR and IHC.

Conclusion

DCA-induced GIM enhanced gastric fat digestion and absorption function and impaired gastric acid secretion function. The DCA-Rikenellaceae RC9 gut group-RGD1311575/Fabp1 axis might play a key role in the mechanism of bile reflux-related GIM.

Management of H. pylori Induced Peptic ulcer – A Phytotherapeutic Approach

A peptic ulcer is a chronic infectious disease that creates erosion on the epithelial lining of the stomach. It is a commonly encountered problem in the gastrointestinal tract (GI tract). Patients failed multiple regimens due to resistant H. pylori infection. H. pylori show maximum resistance towards Clarithromycin. Due to the consistent increase in resistance there is urgent need for the development of new drugs. Paying much for the antibiotic treatment one should go for the natural treatments with no side effects. Modern treatment of peptic ulcers emphasizes diet with routinely recommend hospitalization of several weeks. Currently, a lot of medications are coming out of natural products. The phytotherapeutic approach for the resistant H.pylori treatment is assessed. The plant produces many secondary metabolic substances which have a lot of beneficial roles in maintaining human health. Administration of plant products would prevent disease and able to eradicate resistant H.pylori. This review includes many phytoproducts having a wide range of antimicrobial activity. Reviewed phytoproducts includes Phytoceutical, Caffeic acid, phenethyl ester, Flavonoid, Capsaicin, Carotenoid, etc are effective treatment against H.pylori. To see their effect on the resistant H.pylori and to manage this resistant bacteria with an application of plant products is the prime concern of this review. The linkage between phytochemical and peptic ulcers will provide a novel framework for the future.

Modulatory Role of Carbon Monoxide on the Inflammatory Response and Oxidative Stress Linked to Gastrointestinal Disorders

Significance: Carbon monoxide (CO) is an endogenous gaseous mediator that plays an important role in maintaining gastrointestinal (GI) tract homeostasis, acting in mucosal defense, and providing negative modulation of pathophysiological markers of clinical conditions. Recent Advances: Preclinical studies using animal models and/or cell culture show that CO can modulate the inflammatory response and oxidative stress in GI mucosal injuries and pathological conditions, reducing proinflammatory cytokines and reactive oxygen species, while increasing antioxidant defense mechanisms. Critical Issues: CO has potent anti-inflammatory and antioxidant effects. The defense mechanisms of the GI tract are subject to aggression by different chemical agents (e.g., drugs and ethanol) as well as complex and multifactorial diseases, with inflammation and oxidative stress as strong triggers for the deleterious effects. Thus, it is possible that CO acts on a variety of molecules involved in the inflammatory and oxidative signaling cascades, as well as reinforcing several defense mechanisms that maintain GI homeostasis. Future Directions: CO-based therapies are promising tools for the treatment of GI disorders, such as gastric and intestinal injuries, inflammatory bowel disease, and pancreatitis. Therefore, it is necessary to develop safe and selective CO-releasing agents and/or donor drugs to facilitate effective treatments and methods for analysis of CO levels that are simple and inexpensive. Antioxid. Redox Signal. 37, 98-114.

Gastroprotective Effects of Ganoderma lucidum Polysaccharides with Different Molecular Weights on Ethanol-Induced Acute Gastric Injury in Rats

Ganoderma lucidum is known as a medicine food homology that can ameliorate gastrointestinal diseases. To evaluate the gastroprotective effects on different Ganoderma lucidum polysaccharides (GLPs), GLP was separated into three parts with different molecular weights using 100 kDa, 10 kDa, and 1 kDa membranes. The mitigation effects of different GLPs on ethanol-induced acute gastric injury were observed in rats. After pretreatment with different GLPs, especially GLP above 10 kDa, the symptoms of gastric mucosal congestion and bleeding were improved; serum myeloperoxidase, inflammatory factor, and histamine were decreased; and antioxidant activity and defense factors (NO and EGF) were increased. Results showed that GLP with different molecular weights had a dose-dependent effect in alleviating alcohol-induced gastric injury. The underlying mechanism might be related to regulating anti-oxidation, promoting the release of related defense factors, reducing inflammatory factors, and reducing the level of histamine in serum. The current work indicated that GLPs above 10 kDa could be applied as natural resources for producing new functional foods to prevent gastric injury induced by ethanol.

(-)-Carveol Prevents Gastric Ulcers via Cytoprotective, Antioxidant, Antisecretory and Immunoregulatory Mechanisms in Animal Models

Background: (-)-Carveol (p-Mentha-6,8-dien-2-ol) is a monocyclic monoterpenic alcohol, present in essential oils of plant species such as Cymbopogon giganteus, Illicium pachyphyllum and in spices such as Carum carvi (cumin). Pharmacological studies report its antitumor, antimicrobial, neuroprotective, vasorelaxant, antioxidant and anti-inflammatory activity.

Hypothesis/Purpose: The objective of this study was to evaluate the acute non-clinical oral toxicity, gastroprotective activity of monoterpene (-)-Carveol in animal models and the related mechanisms of action.

Methods: Acute toxicity was assessed according to OECD guide 423 in mice. Ethanol, stress, NSAIDs and pylorus ligation-induced gastric ulcer models were used to investigate antiulcer properties. The related mechanisms of action were using the ethanol-gastric lesions protocol.

Results: (-)-Carveol has low toxicity, with a lethal dose 50% (LD₅₀) equal to or greater than 2,500 mg/kg according to OECD guide nº 423. In all gastric ulcer induction methods evaluated, (-)-Carveol (25, 50, 100 and 200 mg/kg, p.o.) significantly reduced the ulcerative lesion in comparison with the respective control groups. To investigate the mechanisms involved in the gastroprotective activity, the antisecretory or neutralizing of gastric secretion, cytoprotective, antioxidant and immunoregulatory effects were evaluated. In the experimental protocol of pylorus ligation-induced gastric ulcer, (-)-Carveol (100 mg/kg) reduced (p < 0.001) the volume of gastric secretion in both routes (oral and intraduodenal). The previous administration of blockers NEM (sulfhydryl groups blocker), L-NAME (nitric oxide synthesis inhibitor), glibenclamide (K_ATP channel blocker) and indomethacin (cyclo-oxygenase inhibitor), significantly reduced the gastroprotection exercised by (-)-Carveol, suggesting the participation of these pathways in its gastroprotective activity. In addition, treatment with (-)-Carveol (100 mg/kg) increased (p < 0.001) mucus adhered to the gastric wall. Treatment also increased (p < 0.001) levels of reduced glutathione (GSH), superoxide dismutase (SOD) and interleukin-10 (IL-10). It also reduced (p < 0.001) malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) levels.

Conclusion: Thus, it is possible to infer that (-)-Carveol presents gastroprotective activity related to antisecretory, cytoprotective, antioxidant and immunomodulatory mechanisms.

Covering Post-Endoscopic Submucosal Dissection Ulcers in Miniature Swine with Hexanoyl (Hx:C6) Group-Modified Alkaline-Treated Gelatin Porous Film (HAG) Induces Proper Healing by Decreasing Inflammation and Fibrosis

BACKGROUND AND AIMS

Hexanoyl (Hx:C6) group-modified alkaline-treated gelatin porous film (HAG) is a newly developed degradable hydrogel characterized by strong adhesiveness and high affinity for vascular endothelial growth factor (VEGF). The aim of this study was to clarify the effect of HAG sheets on the healing process of post-endoscopic submucosal dissection (ESD) porcine gastric artificial ulcers.

METHODS

(1) To evaluate the adhesiveness of HAG sheets over time, we performed ESD to create 1 artificial ulcer and covered the lesion with 1 HAG sheet using 1 miniature swine. We observed 2 ulcers by endoscopic and microscopic examinations. (2) To examine the effect of HAG sheets on post-ESD ulcer healing, we performed ESD using 5 miniature swine. The artificial ulcers were covered with HAG sheets, or left uncovered after ESD (day 0), followed by macroscopic and microscopic examinations. On days 7 and 14, we observed 2 ulcers by endoscopic examinations. On day 14, the animals were sacrificed, and histological examination was performed on the 3 stomachs that could be extirpated.

RESULTS

(1) On day 7, adhesion of HAG sheets was observed. (2) Gastric ulcer area on day 7 was significantly larger in the covered ulcers than in the non-covered ulcers (p = 0.046). On day 14, although there was no significant difference in ulcer area irrespective of covering (p = 0.357), the covered ulcers tended to repair less fold convergence than non-covered ulcers. The covered ulcer sheets significantly decreased inflammatory cell infiltration (p = 0.011), but significantly increased the abundance of macrophages (p = 0.033), in submucosal layers. Also, the abundance of alpha-smooth muscle actin-positive cells in submucosal layers of the covered ulcers was significantly reduced (p = 0.044), leading to a decrease in collagen accumulation. In addition, fibrosis and atrophy of the muscularis propria were significantly lower for covered ulcers than for non-covered ulcers. Furthermore, microvessels and VEGF-positive cells were significantly more abundant in the submucosal layers of the covered ulcers (p < 0.001 and p = 0.024, respectively).

CONCLUSIONS

HAG sheets induced post-ESD ulcer healing with less submucosal inflammation and muscularis propria injury and have the potential to decrease excess scarring.

Management of patients with digestive diseases during the COVID-19 pandemic. Clinical Practice Guidelines by the Russian scientific medical society of internal medicine (RSMSIM) and the Gastroenterological Scientific Society of Russia (2nd edition)

The presented clinical practice guidelines of the Gastroenterological Scientific Society of Russia (GSSR), diagnostic, and therapeutic approaches for patients with digestive diseases during the COVID-19 pandemic. The guidelines were approved by the XXIII Congress of the GSSR and the 22nd International Slavonic-Baltic Scientifi c Forum “St. Petersburg - Gastro-2020 ON-LINE” (St. Petersburg, June 11, 2020). The presented clinical practice guidelines of the Russian Scientific Medical Society of Internal Medicine (RSMSIM) and the Gastroenterological Scientific Society of Russia (GSSR), diagnostic, and therapeutic approaches for patients with digestive diseases during the COVID-19 pandemic. The recommendations were approved at the XV National Congress of Internal Medicine, XXIII Congress of NOGR on the basis of the 1st edition, adopted at the 22nd International Slavic- Baltic Scientific Forum “St. Petersburg - Gastro-2020 ON-LINE”.

Outcome Predictors of Stroke Mortality in the Neurocritical Care Unit

Background: Risk factors for medium to long-term mortality after stroke are well-established but predictors of in-hospital stroke mortality are less clearly characterized. Kazakhstan has the highest age-standardized mortality rate from ischemic stroke in the world. Methods: We performed a retrospective analysis of patients with stroke who were admitted over a 3.5-years period to the neurocritical care unit of a tertiary care hospital in Nur-Sultan, Kazakhstan. Results: In total, 148 critically ill patients were included in the analysis (84 ischemic stroke, 64 hemorrhagic stroke). The mean age was 63 years, 45% were male and the mean Glasgow Coma Score (±SD) at baseline was 10.3 (±3.4). The in-hospital mortality rate was similar in patients with ischemic (36%) and hemorrhagic (39%) stroke (HR 0.88, 95%CI 0.48-1.60). Median survival was 38 days (range: 1-89 days) in patients with ischemic stroke and 39 days (range: 1-63 days) in patients with hemorrhagic stroke. Univariable analysis found that patients who had a lower Glasgow Coma Scale, were in coma and who had cerebral edema were more likely to die in-hospital (P = 0.04, 0.02, <0.01, respectively). Conclusions: Our analysis showed that mortality risk in critically ill patients with hemorrhagic stroke was closer to mortality risk in patients with ischemic stroke than has been reported in other analyses. Hypertension, chronic heart failure, ischemic heart disease and atrial fibrillation were the most frequent comorbidities in patients who developed severe (life-threatening) stroke. Coma and cerebral edema on admission appear to be associated with poor outcome. This is the first publication of in-hospital stroke mortality from a Central Asian population and could form the basis for future research including development of risk scores and identifying modifiable risk factors.

Tadalafil-Loaded Limonene-Based Orodispersible Tablets: Formulation, in vitro Characterization and in vivo Appraisal of Gastroprotective Activity

Background

Gastric ulcer is a prevalent disease with various etiologies, including non-steroidal anti-inflammatory drugs and alcohol consumption. This study aimed to explore the dual gastric protection effect of tadalafil and limonene as a self-nanoemulsifying system (SNES)-based orodispersible tablets.

Methods

Tadalafil-loaded limonene-based SNES was prepared, and the optimum formula was characterized in terms of particle size (PS), polydispersity index (PDI), and zeta potential (ZP) then loaded on various porous carriers to formulate lyophilized orodispersible tablets (ODTs). The ODTs were evaluated via determining hardness, friability, content uniformity, wetting, and disintegration time. The selected ODT was examined for its gastric ulcer protective effect against alcohol-induced ulcers in rat model. Ulcer score and ulcer index were computed for rats stomachs that were inspected macroscopically and histopathologically.

Results

The prepared SNES had droplet size of 104 nm, polydispersity index of 0.2, and zeta potential of −15.4 mV. From the different ODTs formulated, the formula with superior wetting time: 23.67 s, outstanding disintegration time: 28 s, accepted hardness value: 3.11 kg/cm² and friability: 0.6% was designated. A significant gastroprotective effect of the unloaded and tadalafil-loaded ODTs was recognized compared to the omeprazole pre-treated group. Moreover, the histopathological analysis displayed very mild inflammation in the limonene-based ODTs group and intact structure in the tadalafil-loaded pre-treated animals.

Conclusion

Limonene gastroprotective effect functioned along with tadalafil in the form of SNES-incorporated ODTs could serve as a promising revenue for better efficacy in gastric ulcer prevention.

A Review of the Role of Flavonoids in Peptic Ulcer (2010-2020)

Peptic ulcers are characterized by erosions on the mucosa of the gastrointestinal tract that may reach the muscle layer. Their etiology is multifactorial and occurs when the balance between offensive and protective factors of the mucosa is disturbed. Peptic ulcers represent a global health problem, affecting millions of people worldwide and showing high rates of recurrence. Helicobacter pylori infection and the use of non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most important predisposing factors for the development of peptic ulcers. Therefore, new approaches to complementary treatments are needed to prevent the development of ulcers and their recurrence. Natural products such as medicinal plants and their isolated compounds have been widely used in experimental models of peptic ulcers. Flavonoids are among the molecules of greatest interest in biological assays due to their anti-inflammatory and antioxidant properties. The present study is a literature review of flavonoids that have been reported to show peptic ulcer activity in experimental models. Studies published from January 2010 to January 2020 were selected from reference databases. This review refers to a collection of flavonoids with antiulcer activity in vivo and in vitro models.

Total triterpenoids from the fruits of Chaenomeles speciosa exerted gastroprotective activities on indomethacin-induced gastric damage via modulating microRNA-423-5p-mediated TFF/NAG-1 and apoptotic pathways

Our previous studies have demonstrated that the total triterpenes from the fruits of Chaenomeles speciosa (CSTT) exhibit effective therapeutic effects on gastric ulcer patients and animals. The present aim is to further investigate the mechanisms involved. The results indicated that CSTT could ameliorate IND-induced gastric injury, which was related to promoting IND-damaged GES-1 cell proliferation and migration, improving the IND-damaged rat GBF, ulcer area, inhibition rate and pathologic changes of gastric mucous tissue, increasing the amount of adhered gastric mucus, attenuating the volume and total acidity of the gastric effluents, and augmenting the gastric pH; further studies showed that CSTT obviously downregulated miR-423-5p mRNA, NAG-1 mRNA and protein expression, Bax, Bad, cytosol cytochrome C, Apaf-1, cleaved-caspase-3, and cleaved-caspase-9 protein expression and cytosol cytochrome C concentration, and upregulated TFF1, TFF2 and TFF3 mRNA and protein expression, Bcl-2, Bcl-xl, pro-caspase-3, and pro-caspase-9 protein expression, mitochondrial viability, mitochondrial cytochrome C concentration and Bcl-2/Bax, Bcl-xl/Bad ratios. These findings demonstrated that CSTT protected against IND-induced gastric damage by depressing miR-423-5p expression and modulating the TFF/NAG-1 pathway, which in turn restrained mitochondrion-mediated apoptosis.

Potassium bromate cytotoxicity in the Wister rat model of chronic gastric ulcers: Possible reversal by protocatechuic acid

The interaction between ingested xenobiotics and the gastrointestinal epithelium influences the possibility of gut epithelial cytotoxicity and systemic toxicity. Potassium bromate (KBrO₃ ) has been shown to perturb the central nervous system and it may be carcinogenic, albeit it is used as a food additive. This highlights the need to understand KBrO₃ 's effect on the stomach epithelium. Here, we report the cytotoxic potential of KBrO₃ in an ulcerated stomach, as well as possible cytoprotection by the polyphenol - protocatechuic acid. Potassium bromate (12.5 mg/kg) and protocatechuic acid (120 mg/kg) were administered orally while omeprazole (20 mg/kg) was used as standard. Potassium bromate exacerbated gastric ulcers, increased malonaldehyde levels, catalase, and sodium pump activities, but reduced nitric oxide levels. Potassium bromate further increased mast cell count in the muscularis mucosa, while inducing chronic inflammation and moderate angiogenesis in the gastric mucosa. Our results delineate KBrO₃ -induced gastric epithelial cytotoxicity that is ameliorated by protocatechuic acid. PRACTICAL APPLICATIONS: Potassium bromate is a known food additive in the baking, brewing, and cheese-making process. Conversely, protocatechuic acid (3,4-dihydroxybenzoic acid) is the polyphenolic content of plants like Hibiscus sabdariffa L that are commonly consumed as herbal drink, food, spices, and used in folk medicine. This study reports the cytoprotective effect of protocatechuic acid against gastric mucosa ulceration that has been aggravated by potassium bromate.

Management of patients with digestive diseases during the COVID-19 pandemic: Clinical Practice Guidelines by the Gastroenterological Scientific Society of Russia

The presented clinical practice guidelines of the Gastroenterological Scientific Society of Russia (GSSR), diagnostic, and therapeutic approaches for patients with digestive diseases during the COVID-19 pandemic. The guidelines were approved by the XXIII Congress of the GSSR and the 22nd International Slavonic-Baltic Scientific Forum “St. Petersburg — Gastro-2020 ON-LINE” (St. Petersburg, June 11, 2020).

Protective Effects of Wheat Peptides against Ethanol-Induced Gastric Mucosal Lesions in Rats: Vasodilation and Anti-Inflammation

Alcohol consumption increases the risk of gastritis and gastric ulcer. Nutritional alternatives are considered for relieving the progression of gastric mucosal lesions instead of conventional drugs that produce side effects. This study was designed to evaluate the gastroprotective effects and investigate the defensive mechanisms of wheat peptides against ethanol-induced acute gastric mucosal injury in rats. Sixty male Sprague-Dawley rats were divided into six groups and orally treated with wheat peptides (0.1, 0.2, 0.4 g/kgbw) and omeprazole (20 mg/kgbw) for 4 weeks, following absolute ethanol administration for 1 h. Pretreatment with wheat peptides obviously enhanced the vasodilation of gastric mucosal blood vessels via improving the gastric mucosal blood flow and elevating the defensive factors nitric oxide (NO) and prostaglandin E2 (PGE2), and lowering the level of vasoconstrictor factor endothelin (ET)-1. Wheat peptides exhibited anti-inflammatory reaction through decreasing inducible nitric oxide synthase (iNOS) and pro-inflammatory cytokines tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6, and increasing trefoil factor 1 (TFF1) levels. Moreover, wheat peptides significantly down-regulated the expression of phosphorylated nuclear factor kappa-B (p-NF-κB) p65 proteins in the NF-κB signaling pathway. Altogether, wheat peptides protect gastric mucosa from ethanol-induced lesions in rats via improving the gastric microcirculation and inhibiting inflammation mediated by the NF-κB signaling transduction pathway.

Estragole prevents gastric ulcers via cytoprotective, antioxidant and immunoregulatory mechanisms in animal models

BACKGROUND

Estragole is an aromatic organic compound belonging to the class of phenylpropanoids derived from cinnamic aldehydes and present in essential oils of plant species, such asRavensara anisata (madeira), Ocimum basilicum (manjericão/alfavaca) and Croton zehntneri (canelinha). Pharmacological studies report its anti-inflammatory, antioxidant and vasorelaxant activity.

HYPOTHESIS/PURPOSE

This study aimed to evaluate the acute non-clinical toxicity, gastroprotective activity and the related mechanisms of action.

METHODS

Acute toxicity was assessed according to OECD guide 423 in mice. Ethanol, stress, piroxicam and pylorus ligation-induced gastric ulcer models were used to investigate antiulcer properties. The related mechanisms of action were using the ethanol-gastric lesions protocol.

RESULTS

In the acute oral toxicity assay, doses of 300 or 2000 mg/kg of estragole administered orally in Swiss mice did not induce any behavioral changes. However, the dose of 2000 mg/kg showed a decrease in water and feed intake. Lethal dose 50 % (LD50) was set to be equal to or greater than 2500 mg/kg, according to OECD. In all evaluated protocols, estragole (31.25, 62.5, 125 and 250 mg/kg) significantly reduced the area of ​​ulcerative lesion when compared to control groups. To investigate the mechanisms involved in the gastroprotective activity, the antisecretory or neutralizing of gastric secretion, cytoprotectant, antioxidant and immunoregulatory effects were evaluated. Results showed that treatment with estragole (250 mg/kg) reduced (p < 0.05) the volume of the gastric juice. Besides, sulfhydryl groups, nitric oxide, mucus and prostaglandins seems to be involved in the gastroprotective property. Treatment also increased (p < 0.001) levels of reduced glutathione (GSH), interleukin-10 (IL-10) and positive cells marked for glutathione peroxidase (GPx) and cyclooxygenase 2 (COX-2). It also reduced (p < 0.001) malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and inducible nitric oxide synthase (iNOS) (p < 0.05) levels.

CONCLUSION

Thus, it is possible to infer that estragole presents gastroprotective activity related to antisecretory, cytoprotective, antioxidant and immunomodulatory mechanisms.

Research on the structural characteristics of a novel Chinese Iron Yam polysaccharide and its gastroprotection mechanism against ethanol-induced gastric mucosal lesion in a BALB/c mouse model

In this study, a triple-helix Chinese Iron Yam polysaccharide (CIYP) with a molecular weight of 1.67 × 10³ kDa was obtained. The CIYP was extracted with deionized water followed by deproteination, decoloration and purification using anion-exchange chromatography and size exclusion chromatography. Its structural characteristics and micromorphology were investigated by GC-MS, periodate oxidation and Smith degradation, FT-IR, NMR spectroscopy, SEM and AFM. The results showed that CIYP is a catenarian polysaccharide composed of rhamnose, arabinose, mannose, glucose, galactose and galacturonic acid in the ratio of 1 : 1.33 : 8.31 : 2.83 : 1.12 : 2.62. Meanwhile, the gastric mucosa protective effect of CIYP on an ethanol-injured BALB/c mouse model was investigated. It was found that the preventive CIYP-treatment groups (200 and 400 mg kg^-1 d^-1) showed gastric mucosa protective effects on the BALB/c mouse model. The lesion index and lesion inhibition rate of the CIYP and cimetidine treatment groups were significantly altered compared with the ethanol-induced gastric mucosal lesion (GML) group. Moreover, the administration of CIYP showed definite effects of increasing the NO, PGE2 and EGF levels, and SOD activities, and reducing the MDA levels of gastric mucosa tissues to prevent gastric oxidative stress. Histopathological analysis indicated that the microscopic morphology of gastric mucosal tissues was changed after being damaged by ethanol and the damage was significantly reduced after CIYP administration. Finally, the western blot and quantitative real-time polymerase chain reaction (qRT-PCR) results provided comprehensive evidence that the CIYP could repress gastric inflammation through the reduction of IL-1β, TNF-α and IL-6, prevent gastric oxidative stress through the inhibition of lipid peroxides, and favor cell survival via downregulating the TAK1, MKK3, P-p38 and Bax levels and upregulating the protein expression levels, compared with the CIM group.

Intestinal enteroids recapitulate the effects of short-chain fatty acids on the intestinal epithelium

Enteroids are cultured primary intestinal epithelial cells that recapitulate epithelial lineage development allowing for a more complex and physiologically relevant model for scientific study. The large presence of intestinal stem cells (ISC) in these enteroids allows for the study of metabolite effects on cellular processes and resulting progeny cells. Short-chain fatty acids (SCFA) such as butyrate (BUT) are bacterial metabolites produced in the gastrointestinal tract that are considered to be beneficial to host cells. Therefore, the objective was to study the effects of SCFAs on biomarkers of ISC activity, differentiation, barrier function and epithelial defense in the intestine using mouse and human enteroid models. Enteroids were treated with two concentrations of acetate (ACET), propionate (PROP), or BUT for 24 h. Enteroids treated with BUT or PROP showed a decrease in proliferation via EdU uptake relative to the controls in both mouse and human models. Gene expression of Lgr5 was shown to decrease with BUT and PROP treatments, but increased with ACET. As a result of BUT and PROP treatments, there was an increase in differentiation markers for enterocyte, Paneth, goblet, and enteroendocrine cells. Gene expression of antimicrobial proteins Reg3β, Reg3γ, and Defb1 were stimulated by BUT and PROP, but not by ACET which had a greater effect on expression of tight junction genes Cldn3 and Ocln in 3D enteroids. Similar results were obtained with human enteroids treated with 10 mM SCFAs and grown in either 3D or Transwell™ model cultures, although tight junctions were influenced by BUT and PROP, but not ACET in monolayer format. Furthermore, BUT and PROP treatments increased transepithelial electrical resistance after 24 h compared to ACET or control. Overall, individual SCFAs are potent stimulators of cellular gene expression, however, PROP and especially BUT show great efficacy for driving cell differentiation and gene expression.

Muc5ac null mice are predisposed to spontaneous gastric antro-pyloric hyperplasia and adenomas coupled with attenuated H. pylori-induced corpus mucous metaplasia

Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide and is strongly associated with chronic Helicobacter pylori (Hp) infection. The ability of Hp to closely adhere to the gastric surface protective mucous layer containing mucins (MUC in humans and Muc in animals), primarily Muc5ac, is integral in the stepwise pathogenesis from gastritis to cancer. To probe the role of Muc5ac in Hp-induced gastric pathology, Muc5ac^-/- and Muc5ac^+/+ (WT) mice were experimentally infected with Hp Sydney strain (SS1). At 16 weeks and 32 weeks post infection (wpi), groups of mice were euthanized and evaluated for the following: gastric histopathological parameters, immunohistochemical expression of mucins (Muc5ac, Muc1, Muc2), Trefoil factor family proteins (Tff1 and Tff2), Griffonia (Bandeiraea) simplicifolia lectin II (GSL II) (mucous metaplasia marker) and Clusterin (Spasmolytic Polypeptide Expressing Metaplasia (SPEM) marker), Hp colonization density by qPCR and gastric cytokine mRNA levels. Our results demonstrate that Muc5ac^-/- mice developed spontaneous antro-pyloric proliferation, adenomas and in one case with neuroendocrine differentiation; these findings were independent of Hp infection along with strong expression levels of Tff1, Tff2 and Muc1. Hp-infected Muc5ac^-/- mice had significantly lowered gastric corpus mucous metaplasia at 16 wpi and 32 wpi (P = 0.0057 and P = 0.0016, respectively), with a slight reduction in overall gastric corpus pathology. GSII-positive mucous neck cells were decreased in Hp-infected Muc5ac^-/- mice compared to WT mice and clusterin positivity was noted within metaplastic glands in both genotypes following Hp infection. Additionally, Hp colonization densities were significantly higher in Muc5ac^-/- mice compared to WT at 16 wpi in both sexes (P = 0.05) along with a significant reduction in gastric Tnfα (16 wpi-males and females, P = 0.017 and P = 0.036, respectively and 32 wpi-males only, P = 0.025) and Il-17a (16 wpi-males) (P = 0.025). Taken together, our findings suggest a protective role for MUC5AC/Muc5ac in maintaining gastric antral equilibrium and inhibiting Hp colonization and associated inflammatory pathology.

Induction of Secretagogue Independent Gastric Acid Secretion via a Novel Aspirin-Activated Pathway

Aspirin has been widely recommended for acute and chronic conditions for over 2,000 years. Either single or repetitive doses are commonly used for analgesic and antipyretic reasons and to prevent heart attacks, stroke, and blood clot formation. Recent studies show that it can also be used chronically to dramatically reduce the risk of a variety of cancers. However, prolonged usage of aspirin can cause severe damage to the mucosal barrier, increasing the risk of ulcer formation and GI-bleeding events. In the present study, we show the effects of acute low-dose aspirin exposure as an active secretagogue-inducing gastric acid secretion. Studies were carried out with isolated gastric glands using the pH-sensitive dye BCECF-AM to assess acid secretion. The non-selective NOS inhibitor L-NAME (30 μM), or the specific inhibitor ODQ (1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one) was applied while monitoring intracellular pH. The effects of basolateral exposure to aspirin (acetylsalicylic acid, ASA) caused activation of gastric acid secretion via the H⁺, K⁺-ATPase. Our data suggest that aspirin increases nitric oxide (NO) production, which in turn activates acid secretion. Exposure of gastric glands to either the non-selective NOS inhibitor L-NAME, and the highly selective, soluble guanylyl cyclase inhibitor 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) effectively inhibited aspirin-dependent gastric acid secretion. Aspirin can be considered as a novel secretagogue, in the way that it activates the H⁺, K⁺-ATPase. With increased daily aspirin consumption, our findings have important implications for all individuals consuming aspirin even in low doses and the potential risks for increased acid secretion.

The NCI-N87 Cell Line as a Gastric Epithelial Model to Study Cellular Uptake, Trans-Epithelial Transport, and Gastric Anti-Inflammatory Properties of Anthocyanins

Anthocyanins are ubiquitous plant pigments with reported antioxidant, anti-inflammatory, and anti-cancer activities. To better understand these benefits, metabolism of anthocyanins requires further evaluation, especially in the stomach. Mammalian cell cultures provide useful models for investigating compound metabolism and absorption, but they are generally maintained at physiological pH. The NCI-N87 cell line is an acid-stable model of the gastric epithelium used to study gastric drug metabolism. The objective of this work was to investigate the uptake, trans-epithelial transport, and anti-inflammatory activity of anthocyanins by the NCI-N87 cell line. The cells formed a coherent monolayer, stable ≤32 days post confluency. Minimal effects on monolayer integrity were observed when the pH of the apical chamber was adjusted to pH 3.0, 5.0, or 7.4. Anthocyanins were transported across the NCI-N87 cell monolayer at 37 °C, but not at 0 °C, suggesting a facilitated process. Chokeberry anthocyanins (0-1500 μM) were not cytotoxic. At apical pH 3.0, they had anti-inflammatory properties by significantly attenuating IL-8 secretion when added to medium before, during, and after incubation with IL-1β. These results suggest that the NCI-N87 cell line is a physiologically relevant model for in vitro studies of the transport, anti-inflammatory and potential anti-carcinogenic activities of anthocyanins in gastric tissue.

Gastroduodenal Injury: Role of Protective Factors

PURPOSE OF REVIEW

The gastroduodenal mucosal layer is a complex and dynamic system that functions in an interdependent manner to resist injury. We review and summarize the most updated knowledge about gastroduodenal defense mechanisms and specifically address (a) the mucous barrier, (b) membrane and cellular properties, and vascular, hormonal, and (c) gaseous mediators.

RECENT FINDINGS

Trefoil factor family peptides play a crucial role in cellular restitution by increasing cellular permeability and expression of aquaporin channels, aiding cellular migration and tissue repair. Additionally, evidence suggests that the symptoms of functional dyspepsia may be attributed to alterations in the duodenum, including low-grade inflammation and increased mucosal permeability. The interaction of the various mucosal protective components helps maintain structural and functional homeostasis. There is increasing evidence suggesting that the upper GI microbiota plays a crucial role in the defense mechanisms. However, this warrants further investigation.

Chemical composition, antioxidant and gastrointestinal properties of Sedum dendroideum Moc & Sessé ex DC leaves tea infusion

ETHNOPHARMACOLOGICAL RELEVANCE

Sedum dendroideum Moc & Sessé ex DC (Crassulaceae) is a medicinal plant employed in Mexican and Brasilian folk medicine as juice or infusion, as remedy for the treatment of different diseases, including gastric disorders.

AIM OF THE STUDY

Although some studies carried out with Sedum dendroideum have demonstrated its gastroprotective effect, the purpose of this study was to elucidate the chemical constituents, antioxidant, cytotoxic and mechanisms underlying the gastrointestinal properties of Sedum dendroideum accordingly its traditional use, as fresh leaves tea infusion (SDI).

MATERIALS AND METHODS

Chemical constituents were analyzed using high performance liquid chromatography and mass spectrometry (HPLC-MS). Antioxidant and cytotoxicity were evaluated in in vitro assays. The efficacy of the SDI on macroscopic ulcer appearance, mucus and GSH maintenance on ethanol- and indomethacin-induced ulcer models, gastric acid secretion and gastrointestinal motility were investigated.

RESULTS

Phytochemical analysis by HPLC-MS revealed the presence of different flavonol glycosides, containing myricetin and quercetin, along with the kaempferol as aglycones. In vitro pharmacological investigation of SDI demonstrated potent antioxidant activity in DPPH assay (IC50: 13.25 ± 3.37 µg/mL) and absence of cytotoxicity in Caco-2 cells by MTT method. Oral administration of SDI (ED₅₀ of 191.00 ± 0.08 mg/kg) in rats promoted gastroprotection against ethanol or indomethacin in rats through reinforcement of gastric wall mucus, GSH content and nitric oxide release, without present antisecretory properties. The gastroprotective effect was maintained when SDI (19 mg/kg) was administrated by intraperitoneal route. Furthermore, SDI (150 mg/kg) unchanged the gastric emptying but increase small bowel transit in mice through cholinergic pathways.

CONCLUSIONS

Collectively, this study confirmed that Sedum dendroideum promotes gastroprotection through preventing of endogenous defense mechanisms, represented by mucus and GSH without changes gastric acid secretion. Sedum dendroideum tea infusion features a chemical profile that contributes to the antioxidant and gastric health-promoting effects, supporting the use in folk medicine for the treatment of gastrointestinal disorders.

Effects of artemisinin, with or without lumefantrine and amodiaquine on gastric ulcer healing in rat

Background

Antimalarial drugs have been shown to predispose the stomach to ulceration in rats. However, their role in the modulation of gastric ulcer healing is not known. The aim of the present study is to investigate the effect of artemisinin-based combination therapies on ulcer healing.

Methods

Gastric kissing ulcers were induced in 40 male albino rats (150–180 g) using 0.2 mL 50% acetic acid. One day after the ulcer induction, experimental rats were divided into four groups and treated once daily orally for 3 days as follows: (1) normal saline, (2) artemether-lumefantrine (2/12 mg/kg), (3) artesunate-amodiaquine (4/10 mg/kg), and (4) artesunate (2 mg/kg) only. A fifth group of 10 rats served as overall control with no ulcer induced and no treatment given. Ulcer healing was determined on days 4 and 7 post induction using ulcer score and planimetry.

Results

Artesunate decreased ulcer severity by 12.5% and 52.0% on days 4 and 7, respectively. Significant increases in severity were observed in rats treated with artemether-lumefantrine (25.0% and 40.0%) and artesunate-amodiaquine (50.0% and 95.0%). Lipid peroxidation was decreased by artesunate by day 7 (27%; p<0.05) but increased in artemether-lumefantrine and artesunate-amodiaquine administered rats (63.6% and 55%; p<0.05). The activity of superoxide dismutase was reduced by artesunate-amodiaquine on day 7 (22%; p<0.05) but no effect in the artemether-lumefantrine treatment. Neutrophil infiltration, total leukocyte count, neutrophil-lymphocyte ratio, and C-reactive protein values were significantly increased in the artemether-lumefantrine and artesunate-amodiaquine treated groups when compared with the untreated ulcer control group (p<0.05). These variables were all reduced by artesunate (p<0.05).

Conclusions

This study revealed that although artesunate may be beneficial in gastric ulcer healing, its combination with either lumefantrine or amodiaquine may delay healing of gastric mucosal injury.

Invited review: Abomasal damage in veal calves

Within all cattle production systems, veal calves are the most severely affected by abomasal damage, with current prevalence at slaughter ranging from 70 to 93% of all animals affected. Although most damage is found in the pyloric region of the abomasum, fundic lesions are also found. Despite past research into the etiology of abomasal damage and the many risk factors that have been proposed, consensus on the causal factors of abomasal damage in veal calves has not yet been reached. The aim of this review was to integrate and analyze available information on the etiology of, and possible risk factors for, abomasal damage in veal calves. We describe various proposed pathways through which risk factors may contribute to damage formation and conclude that the etiology of abomasal damage is most likely multifactorial, with diet being a main contributor. Pyloric lesions, the most common type of damage in veal calves, are likely the result of large and infrequent milk and solid feed meals, whereas fundic lesions may be caused by stress, although the evidence for this is inconclusive. Providing calves with multiple smaller milk and solid feed meals (or ad libitum provision) may decrease abomasal damage. In future research, ulcers, erosions, and scars as well as fundic and pyloric lesions should be recorded separately, because etiologies of these may differ. Further research is required to understand the exact pathway(s) by which milk replacer causes abomasal damage in veal calves; that is, whether low abomasal pH, overloading, or composition are important. Further research is also required to elucidate whether rapid intake of milk replacer and solid feed, which is influenced by restricted amounts fed, inter-calf competition, and calf breed, increases abomasal damage. Research is also needed into the effect of medication and nutrient deficiencies other than iron. The types of experimental designs that can be used for future research could be enhanced if a means to assess abomasal damage antemortem is developed. We conclude that it is unlikely that abomasal or ruminal hairballs, iron deficiency, water provision, and various infections and diseases are significant contributors to abomasal damage in veal calves.

Evaluation of gastroprotective and ulcer healing activities of yellow mombin juice from Spondias mombin L

Spondias mombin L. (yellow mombin) is a tree with a nutritional fruit that is commonly consumed in the North and Northeast of Brazil, as the juice of its pulp is rich in antioxidant compounds. This study aimed to investigate the gastroprotective and ulcer healing activities of yellow mombin juice (YMJ) in Wistar rats, and to elucidate the possible involved mechanisms. Phytochemical characterization of the lyophilized fruit juice was performed by high-performance liquid chromatography (HPLC). The gastroprotective activity of YMJ was investigated in ethanol (25, 50, and 100% YMJ) and indomethacin (100% YMJ) models of acute gastric ulcer in rats. Then, the effect of YMJ on mucus production and gastric secretions, and the involvement of non-protein sulfhydryl groups and prostaglandins in the gastroprotective process were examined. Moreover, the ulcer healing effect of YMJ was investigated in a model of acetic acid-induced chronic ulcer through histological and immunohistochemical analyses. HPLC results identified the presence of epicatechin (7.1 ± 1.6 μg/mL) and quercetin (17.3 ± 2.5 μg/mL) in YMJ. Ethanol-induced gastric lesions were inhibited by YMJ (25, 50, and 100%) by 42.42, 45.09, and 98.21% respectively, and indomethacin-induced lesions were inhibited by YMJ (100%) by 58.96%, compared to control group. Moreover, YMJ reduced gastric content and total acidy by 57.35 and 71.97%, respectively, compared to the control group. Treatment with YMJ also promoted healing of chronic ulcer, regeneration of the gastric mucosa, and restoration of mucus levels in glandular cells, as confirmed by histological analysis. It also increased cellular proliferation, as demonstrated by high reactivity to Ki-67 and bromodeoxyuridine. In conclusion, YMJ was found to possess gastroprotective and ulcer healing activities that are correlated to its antisecretory action. These results support the commercial exploration of YMJ as a functional food.

Identification of Novel Cryptic Multifunctional Antimicrobial Peptides from the Human Stomach Enabled by a Computational-Experimental Platform

Novel approaches are needed to combat antibiotic resistance. Here, we describe a computational-experimental framework for the discovery of novel cryptic antimicrobial peptides (AMPs). The computational platform, based on previously validated antimicrobial scoring functions, indicated the activation peptide of pepsin A, the main human stomach protease, and its N- and C-terminal halves as antimicrobial peptides. The three peptides from pepsinogen A3 isoform were prepared in a recombinant form using a fusion carrier specifically developed to express toxic peptides in Escherichia coli. Recombinant pepsinogen A3-derived peptides proved to be wide-spectrum antimicrobial agents with MIC values in the range 1.56-50 μM (1.56-12.5 μM for the whole activation peptide). Moreover, the activation peptide was bactericidal at pH 3.5 for relevant foodborne pathogens, suggesting that this new class of previously unexplored AMPs may contribute to microbial surveillance within the human stomach. The peptides showed no toxicity toward human cells and exhibited anti-infective activity in vivo, reducing by up to 4 orders of magnitude the bacterial load in a mouse skin infection model. These peptides thus represent a promising new class of antibiotics. We envision that computationally guided data mining approaches such as the one described here will lead to the discovery of antibiotics from previously unexplored sources.

Accelerated gastric ulcer healing in thyroxine-treated rats: roles of gastric acid, mucus, and inflammatory response

The roles of gastric acid, mucus, and inflammation on the pro-ulcer-healing effect of thyroid hormone were investigated. Male Wistar rats were randomly divided into four groups: control, thyroidectomised, thyroidectomised with thyroxine treatment (100 μg·kg–1·day–1), and sham-operated animals treated with thyroxine. Thirty-five days after thyroidectomy, sham surgery, or thyroxine treatment, an ulcer was experimentally induced. Healing was assessed 3, 7, and 10 days post-ulceration by measurement of the ulcer area, gastric mucus and acid secretion, and neutrophil lymphocyte ratio (NLR) as an index of inflammation. By day 10, the ulcer area had decreased in all groups. Recovery was significantly greater (P < 0.05) in thyroxine-treated rats (78.5% ± 1.6% reduction in ulcer area) than in controls (72.3% ± 1.2% reduction) or thyroidectomised rats (63.3% ± 1.9% reduction). Thyroxine-treated animals also had the highest reduction in NLR (65.0% ± 2.5%). Mucus secretion was significantly lower (P < 0.05) in thyroidectomised rats by days 3 and 7. Furthermore, by day 10, the concentration of basal acid decreased by 77.4% ± 2.6% in thyroxine-treated, 65.0% ± 0.0% in control, and 51.5% ± 3.3% in thyroidectomised rats. We conclude that thyroxine accelerates gastric ulcer healing by altering mucus and acid secretion and reducing NLR.

Acid and the basis for cellular plasticity and reprogramming in gastric repair and cancer

Subjected to countless daily injuries, the stomach still functions as a remarkably efficient digestive organ and microbial filter. In this Review, we follow the lead of the earliest gastroenterologists who were fascinated by the antiseptic and digestive powers of gastric secretions. We propose that it is easiest to understand how the stomach responds to injury by stressing the central role of the most important gastric secretion, acid. The stomach follows two basic patterns of adaptation. The superficial response is a pattern whereby the surface epithelial cells migrate and rapidly proliferate to repair erosions induced by acid or other irritants. The stomach can also adapt through a glandular response when the source of acid is lost or compromised (that is, the process of oxyntic atrophy). We primarily review the mechanisms governing the glandular response, which is characterized by a metaplastic change in cellular differentiation known as spasmolytic polypeptide-expressing metaplasia (SPEM). We propose that the stomach, like other organs, exhibits marked cellular plasticity: the glandular response involves reprogramming mature cells to serve as auxiliary stem cells that replace lost cells. Unfortunately, such plasticity might mean that the gastric epithelium undergoes cycles of differentiation and de-differentiation that increase the risk of accumulating cancer-predisposing mutations.

Mechanisms of curcumin-induced gastroprotection against ethanol-induced gastric mucosal lesions

BACKGROUND

Curcumin, a pleiotropic substance used for centuries in traditional medicine, exhibits antioxidant, anti-inflammatory and antiproliferative efficacy against various tumours, but the role of curcumin in gastroprotection is little studied. We determined the effect of curcumin against gastric haemorrhagic lesions induced by 75% ethanol and alterations in gastric blood flow (GBF) in rats with cyclooxygenase-1 (COX-1) and COX-2 activity inhibited by indomethacin, SC-560 or rofecoxib, inhibited NO-synthase activity, capsaicin denervation and blockade of TRPV1 receptors by capsazepine.

METHODS

One hour after ethanol administration, the gastric mucosal lesions were assessed by planimetry, the GBF was examined by H2 gas clearance, plasma gastrin was determined by radioimmunoassay, and the gastric mucosal mRNA expression of Cdx-2, HIF-1α, HO-1 and SOD 2 was analysed by RT-PCR.

RESULTS

Curcumin, in a dose-dependent manner, reduced ethanol-induced gastric lesions and significantly increased GBF and plasma gastrin levels. Curcumin-induced protection was completely reversed by indomethacin and SC-560, and significantly attenuated by rofecoxib, L-NNA, capsaicin denervation and capsazepine. Curcumin downregulated Cdx-2 and Hif-1α mRNA expression and upregulated HO-1 and SOD 2, and these effects were reversed by L-NNA and further restored by co-treatment of L-NNA with L-arginine.

CONCLUSIONS

Curcumin-induced protection against ethanol damage involves endogenous PG, NO, gastrin and CGRP released from sensory nerves due to activation of the vanilloid TRPV1 receptor. This protective effect can be attributed to the inhibition of HIF-1α and Cdx-2 expression and the activation of HO-1 and SOD 2 expression.

Antiulcer Activity and Potential Mechanism of Action of the Leaves of Spondias mombin L

Spondias mombin L. is used in folk medicine for the treatment of inflammation and gastrointestinal diseases. Our study investigated the antiulcer activity of S. mombin ethanolic extract (SmEE) and its majority compounds gallic acid (GA) and ellagic acid (EA). Phytochemical characterization was performed by HPLC. The SmEE was screened for in vitro antioxidant activities using phosphomolybdenum, ABTS, DPPH, and FRAP assays. The antiulcer activity of SmEE, GA, EA, or GA + EA was evaluated by gastric lesion models induced by absolute ethanol and indomethacin. Following this, it is capable of stimulating mucus production, antisecretory capacity, and the influence of −SH groups and NO in the effect of SmEE. Its healing activity was demonstrated by acetic acid-induced chronic ulcer model. Anti-Helicobacter pylori activity was assessed by determining the MIC of the SmEE (64–1024 μg/mL). The HPLC results identified the presence of gallic acid and ellagic acid in SmEE. The extract showed antioxidant activity in vitro. SmEE (50, 100, and 200 mg/kg) reduced the area of ulcerative lesions induced by ethanol in 23.8, 90.3, and 90.2%, respectively. In NSAID model, the SmEE induced protection of 36.8, 49.4, and 49.9%, respectively. GA (10 mg/kg) or EA (7 mg/kg) or the association of GA + EA (10 + 7 mg/kg) inhibited the ethanol-induced lesions in 71.8, 70.9, and 94.9%, respectively, indicating synergistic action. SmEE (100 mg/kg) decreased acid secretion and H⁺ concentration in the gastric contents, increased levels of mucus, and showed to be dependent of −SH groups and NO on the protection of the gastric mucosa. In chronic ulcer model, SmEE reduced the gastric area lesion. SmEE showed anti-H. pylori activity. In conclusion, our study showed that SmEE has antiulcerogenic activity. GA and EA are isolated gastric protectors and, when associated, acted synergistically to protect the gastric mucosa.

A slippery slope: On the origin, role and physiology of mucus

The mucosa of the gastrointestinal tract, eyes, nose, lungs, cervix and vagina is lined by epithelium interspersed with mucus-secreting goblet cells, all of which contribute to their unique functions. This mucus provides an integral defence to the epithelium against noxious agents and pathogens. However, it can equally act as a barrier to drugs and delivery systems targeting epithelial passive and active transport mechanisms. This review highlights the various mucins expressed at different mucosal surfaces on the human body, and their role in creating a mucoid architecture to protect epithelia with specialized functions. Various factors compromising the barrier properties of mucus have been discussed, with an emphasis on how disease states and microbiota can alter the physical properties of mucus. For instance, Akkermansia muciniphila, a bacterium found in higher levels in the gut of lean individuals induces the production of a thickened gut mucus layer. The aims of this article are to elucidate the different physiological, biochemical and physical properties of bodily mucus, a keen appreciation of which will help circumvent the slippery slope of challenges faced in achieving effective mucosal drug and gene delivery.

Gastroprotective activity of polysaccharide from Hericium erinaceus against ethanol-induced gastric mucosal lesion and pylorus ligation-induced gastric ulcer, and its antioxidant activities

The gastroprotective activity of Hericium erinaceus polysaccharide was investigated in rats. The antioxidant activities were also evaluated. Pre-treatment of polysaccharide could reduce ethanol-induced gastric mucosal lesion and pylorus ligation-induced gastric ulcer. The polysaccharide exhibited scavenging activities of 1, 1-diphenyl-2-picryl-hydrozyl and hydroxyl radicals, and ferrous ion-chelating ability. In the pylorus ligation-induced model, gastric secretions (volume of gastric juice, gastric acid, pepsin and mucus) of ulcer rats administrated with polysaccharide were regulated. Levels of tumor necrosis factor-α and interleukins-1β in serum, and myeloperoxidase activity of gastric tissue were reduced, while antioxidant status of gastric tissue was improved. Defensive factors (nitric oxide, prostaglandin E2, epidermal growth factor) in gastric tissue were increased. These results indicate that Hericium erinaceus polysaccharide possess gastroprotective activity, and the possible mechanisms are related to its regulations of gastric secretions, improvements of anti-inflammatory and antioxidant status, as well as increments of defensive factors releases.

Gastroprotective Value of Berries: Evidences from Methanolic Extracts of Morus nigra and Rubus niveus Fruits

This study evaluated the gastroprotective value of the methanol extracts from fruits of Morus nigra L. (black mulberry (MEMN)) and Rubus niveus Thunb (raspberry (MERN)). The total phenolic compounds and flavonoids were measured, as well as the in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenger activity. The gastroprotective effects of the extracts against 60% ethanol/0.3 M HCl were evaluated in mice. After that, the lipid hydroperoxides and reduced glutathione levels at ulcerated tissue were determined. The effects of extracts on H⁺/K⁺-ATPase activity were also verified. The extracts exhibited high contents of polyphenols; however, MERN presented 1.5-fold higher levels. The presence of flavonoids also was confirmed. In addition, MEMN (IC₅₀ = 13.74 μg/mL) and MERN (IC₅₀ = 14.97 μg/mL) scavenged DPPH radical. The MEMN reduced the ulcer area only at 300 mg/kg (p.o.) by 64.06%. Interestingly, MERN decreased the ulcer area in a superior potency (ED₅₀ = 20.88 mg/kg), reducing the ulcer area by 81.86% at 300 mg/kg, and increased the gastric mucin levels. The antioxidant effects of extracts were evidenced by reduced lipoperoxides and increased reduction of glutathione amount in the gastric mucosa. However, MEMN or MERN did not change the H⁺/K⁺-ATPase activity. These results confirm that M. nigra and R. niveus are berries with a gastroprotective value by strengthening of gastric protective factors.

Effects of quinine on gastric ulcer healing in Wistar rats

Background Quinine (QT) is an important anti-malarial drug; however, there is little information about its effects on the gut. Therefore, this study aimed to investigate the effects of a therapeutic dose of QT on the healing of gastric ulcer in rats. Methods Male Wistar rats weighing 150-200 g were divided into three groups: control rats without ulcer (group 1), ulcerated rats treated with 1 mL/kg (p.o.) normal saline (NS) (group 2), and ulcerated rats treated with 10 mg/kg (p.o.) QT (group 3). Ulcers were induced by serosal application of 80 % acetic acid to the stomach of rats anaesthetized with 50 mg/kg thiopentone sodium and treatment was given three times daily. Healing was assessed on days 3, 7 and 10 after ulcer induction by macroscopic measurement of: ulcer area, histology, lipid peroxidation, superoxide dismutase activity and gastric mucus secretion. Results At day 3, there was no significant difference (p>0.05) in ulcer areas between NS- and QT-treated rats. By day 10, however, the percentage area healed in NS treated (59.6±2.35 %) was significantly higher (p<0.05) than in QT rats (49.0±2.20 %) and clearing of inflammatory cells and re-epithelization was greater in NS-treated group. By days 7 and 10, lipid peroxidation was significantly higher in QT animals, when compared with NS-treated rats and controls (p<0.05). Superoxide dismutase activity and mucus secretion were significantly (p<0.05) higher in NS-treated than QT-treated rats. Conclusions QT delayed ulcer healing by prolonging the inflammatory phase of healing, increasing oxidative stress, reducing antioxidant activity and gastric mucus secretion.

An approach to the research on ion and water properties in the interphase between the plasma membrane and bulk extracellular solution

In vivo, cells are immersed in an extracellular solution that contains a variety of bioactive substances including ions and water. Classical electrophysiological analyses of epithelial cells in the stomach and small intestine have revealed that within a distance of several hundred micrometers above their apical plasma membrane, lies an extracellular layer that shows ion concentration gradients undetectable in the bulk phase. This “unstirred layer”, which contains stagnant solutes, may also exist between the bulk extracellular solution and membranes of other cells in an organism and may show different properties. On the other hand, an earlier study using a bacterial planar membrane indicated that H⁺ released from a transporter migrates in the horizontal direction along the membrane surface much faster than it diffuses vertically toward the extracellular space. This result implies that between the membrane surface and unstirred layer, there is a “nanointerface” that has unique ionic dynamics. Advanced technologies have revealed that the nanointerface on artificial membranes possibly harbors a highly ordered assembly of water molecules. In general, hydrogen bonds are involved in formation of the ordered water structure and can mediate rapid transfer of H⁺ between neighboring molecules. This description may match the phenomenon on the bacterial membrane. A recent study has suggested that water molecules in the nanointerface regulate the gating of K⁺ channels. Here, the region comprising the unstirred layer and nanointerface is defined as the interphase between the plasma membrane and bulk extracellular solution (iMES). This article briefly describes the physicochemical properties of ions and water in the iMES and their physiological significance. We also describe the methodologies that are currently used or will be applicable to the interphase research.

Gastric acid inhibitory and gastric protective effects of Cannabis and cannabinoids

Cannabis sativa has long been known for its psychotropic effect. Only recently with the discovery of the cannabinoid receptors, their endogenous legends and the enzymes responsible for their synthesis and degradation, the role of this 'endocannabinoid system' in different pathophysiologic processes is beginning to be delineated. There is evidence that CB1 receptor stimulation with synthetic cannabinoids or Cannabis sativa extracts rich in Δ(9)-tetrahydrocannabinol inhibit gastric acid secretion in humans and experimental animals. This is specially seen when gastric acid secretion is stimulated by pentagastrin, carbachol or 2-deoxy-d-glucose. Cannabis and/or cannabinoids protect the gastric mucosa against noxious challenge with non-steroidal anti-inflammatory drugs, ethanol as well as against stress-induced mucosal damage. Cannabis/cannabinoids might protect the gastric mucosa by virtue of its antisecretory, antioxidant, anti-inflammatory, and vasodilator properties.

Shuidouchi (Fermented Soybean) Fermented in Different Vessels Attenuates HCl/Ethanol-Induced Gastric Mucosal Injury

Shuidouchi (Natto) is a fermented soy product showing in vivo gastric injury preventive effects. The treatment effects of Shuidouchi fermented in different vessels on HCl/ethanol-induced gastric mucosal injury mice through their antioxidant effect was determined. Shuidouchi contained isoflavones (daidzein and genistein), and GVFS (glass vessel fermented Shuidouchi) had the highest isoflavone levels among Shuidouchi samples fermented in different vessels. After treatment with GVFS, the gastric mucosal injury was reduced as compared to the control mice. The gastric secretion volume (0.47 mL) and pH of gastric juice (3.1) of GVFS treated gastric mucosal injury mice were close to those of ranitidine-treated mice and normal mice. Shuidouchi could decrease serum motilin (MTL), gastrin (Gas) level and increase somatostatin (SS), vasoactive intestinal peptide (VIP) level, and GVFS showed the strongest effects. GVFS showed lower IL-6, IL-12, TNF-α and IFN-γ cytokine levels than other vessel fermented Shuidouchi samples, and these levels were higher than those of ranitidine-treated mice and normal mice. GVFS also had higher superoxide dismutase (SOD), nitric oxide (NO) and malonaldehyde (MDA) contents in gastric tissues than other Shuidouchi samples. Shuidouchi could raise IκB-α, EGF, EGFR, nNOS, eNOS, Mn-SOD, Gu/Zn-SOD, CAT mRNA expressions and reduce NF-κB, COX-2, iNOS expressions as compared to the control mice. GVFS showed the best treatment effects for gastric mucosal injuries, suggesting that glass vessels could be used for Shuidouchi fermentation in functional food manufacturing.