Alterations in Gastric Mucosal Expression of Calcitonin Gene-Related Peptides, Vanilloid Receptors, and Heme Oxygenase-1 Mediate Gastroprotective Action of Carbon Monoxide against Ethanol-Induced Gastric Mucosal Lesions

Targeting TRPV1 signaling: Galangin improves ethanol-induced gastric mucosal injury

ETHNOPHARMACOLOGICAL RELEVANCE

Galangin, a bioactive compound extracted from Alpinia officinarum Hance (Zingiberaceae), a plant with significant ethnopharmacological importance, has been used for thousands of years as a spice, condiment, and medicinal agent for various conditions, including gastrointestinal disorders. Although there is evidence suggesting its potential to improve gastric ulcers, the molecular mechanisms underlying its anti-ulcer properties are not fully understood.

OBJECTIVE

of the Study: This study aimed to investigate the effects of galangin on ethanol-induced acute gastric mucosal injury (AGMI) in mice and elucidate its molecular mechanisms.

MATERIALS AND METHODS

Sixty BALB/c mice were randomly assigned into two main groups: a normal control group (n = 10) and an ethanol-induced group (n = 50). After establishing the AGMI model in mice using a combination of 40% ethanol and anhydrous ethanol, the ethanol-induced group was further subdivided into five subgroups (n = 10): an omeprazole control group (20 mg/kg), an untreated ethanol group, and three treatment groups receiving high-dose (50 mg/kg) or low-dose (25 mg/kg) galangin or capsazepine (CPZ, 2 mg/kg). The protective effects of galangin were evaluated through mucosal injury indices, hematoxylin and eosin staining, and quantification of inflammatory markers (IL-1β, IL-6, IL-8, and TNF-α). Oxidative stress levels and matrix metalloproteinase activity were measured using specific assay kits. Molecular docking was conducted to assess the binding affinity of galangin to key proteins within the transient receptor potential vanilloid 1 (TRPV1) pathway. Real-time fluorescence quantitative PCR (qPCR) was used to determine mRNA expression levels of TRPV1, calmodulin (CaM), substance P (SP), and CGRP in gastric tissues. Protein expression levels of TRPV1, nerve growth factor (NGF), tropomyosin receptor kinase A (TRKA), transforming growth factor beta (TGF-β), cyclooxygenase-2 (COX-2), and nuclear factor kappa B (NF-κB) were assessed through Western blot analysis. In cellular experiments, Culture of Human Gastric Epithelial Cells (GES-1) were treated with various concentrations of galangin after 7% ethanol induction. Cell proliferation, apoptosis, and migration were evaluated using Hoechst 33258 staining and transwell migration assays. TRPV1 protein expression was detected using immunofluorescence, and the expression levels of Bcl-2, BCL2-Associated X (BAX), and Caspase-3 were quantified by qPCR. Additionally, specific probe kits were used to measure intracellular calcium ions (Ca2+) and mitochondrial membrane potential.

RESULTS

The findings indicate that galangin significantly improved mucosal pathology by reducing ulcer indices and inflammatory levels, while enhancing superoxide dismutase (SOD) activity and decreasing malondialdehyde (MDA) concentration. Galangin also reduced matrix metalloproteinase-2 (MMP-2), m metalloproteinase-9 (MMP-9) levels, promoting mucosal repair. At the cellular level, galangin decreased intracellular calcium ion concentration and mitigated the decline in mitochondrial membrane potential, enhance the restoration of mucosal cells, increased migration and proliferation, and reduced apoptosis. Molecularly, galangin demonstrated favorable binding to TRPV1, NGF, TRKA, TGF-β, COX-2, and NF-κB, and reversed the elevated expression of these proteins. Additionally, galangin downregulated the mRNA expression of TRPV1, CaM, SP, CGRP, BAX, and Caspase-3 in gastric tissues/cells, while upregulating Bcl-2 mRNA expression.

CONCLUSION

Galangin mitigates AGMI by inhibiting the overactivation of the TRPV1 pathway, thereby blocking aberrant signal transduction. This study suggests that galangin has therapeutic potential against ethanol-induced AGMI and may be a viable alternative for the treatment of alcohol-induced gastric mucosal injuries.

Integrated network pharmacology and metabolomics to investigate the effects and possible mechanisms of Dehydroevodiamine against ethanol-induced gastric ulcers

ETHNOPHARMACOLOGICAL RELEVANCE

Tetradium ruticarpum (A.Juss.) T.G.Hartley, a traditional Chinese medicine with thousands of years of medicinal history, has been employed to address issues such as indigestion, abdominal pain, and vomiting. Dehydroevodiamine (DHE) is a quinazoline alkaloid extracted from traditional Chinese medicine Tetradium ruticarpum (A.Juss.) T.G.Hartley. Previous studies have shown that DHE has anti-inflammatory, analgesic, and antioxidant activities. However, it is still unclear whether DHE has an effect on ethanol-induced gastric ulcers.

AIM OF THE STUDY

The objective of this study is to investigate the therapeutic efficacy and underlying mechanisms of action of DHE on ethanol-induced gastric ulcers using network pharmacology and metabolomics strategies.

METHODS

In this study, we used ethanol-induced rats as a model to assess the efficacy of DHE by biochemical indicator assays and pathological tissue detection. The integration of network pharmacology and metabolomics was used to explore possible mechanisms and was validated by western blot experiments. Finally, molecular docking was used to analyze the binding energy between DHE and the targets of PIK3CG and PLA2G2A.

RESULTS

DHE was able to reverse ethanol-induced abnormalities in biochemical indicators and improve pathological tissue. Network pharmacology results indicated that DHE may be involved in the regulation of gastric ulcers by modulating 79 targets, and metabolomics results showed that a total of 13 metabolites were changed before and after DHE administration. Integrating network pharmacology and metabolomics, PIK3CG and PLA2G2A were identified as possible targets to exert therapeutic effects. In addition, the MAPKs pathway may also be involved in the regulation of ethanol-induced gastric ulcers. Finally, molecular docking results showed that DHE had low binding energies with both PIK3CG and PLA2G2A.

CONCLUSIONS

These findings suggest that DHE was able to exert a protective effect against ethanol-induced gastric ulcers by modulating multiple metabolites with multiple targets. This study provides a valuable reference for the development of antiulcer drugs.

Calcitonin Gene-Related Peptide Systemic Effects: Embracing the Complexity of Its Biological Roles-A Narrative Review

The calcitonin gene-related peptide (CGRP) is a neuropeptide widely distributed throughout the human body. While primarily recognized as a nociceptive mediator, CGRP antagonists are currently utilized for migraine treatment. However, its role extends far beyond this, acting as a regulator of numerous biological processes. Indeed, CGRP plays a crucial role in vasodilation, inflammation, intestinal motility, and apoptosis. In this review, we explore the non-nociceptive effects of CGRP in various body systems, revealing actions that can be contradictory at times. In the cardiovascular system, it functions as a potent vasodilator, yet its antagonists do not induce arterial hypertension, suggesting concurrent modulation by other molecules. As an immunomodulator, CGRP exhibits intriguing complexity, displaying both anti-inflammatory and pro-inflammatory effects. Furthermore, CGRP appears to be involved in obesity development while paradoxically reducing appetite. A thorough investigation of CGRP's biological effects is crucial for anticipating potential side effects associated with its antagonists' use and for developing novel therapies in other medical fields. In summary, CGRP represents a neuropeptide with a complex systemic impact, extending well beyond nociception, thus offering new perspectives in medical research and therapeutics.

Crosstalk between TRPV1 and immune regulation in Fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD) is the leading indication for corneal transplantation worldwide. Our aim was to investigate the role of transient receptor potential vanilloid subtype 1 (TRPV1) and the associated immune regulation contributing to this pathological condition. Significant upregulation of TRPV1 was detected in the H2O2-induced in vitro FECD model. Based on gene expression microarray dataset GSE142538 and in vitro results, a comprehensive immune landscape was studied and a negative correlation was found between TRPV1 with different immune cells, especially regulatory T cells (Tregs). Functional analyses of the 313 TRPV1-related differentially expressed genes (DEGs) revealed the involvement of TRP-regulated calcium transport, as well as inflammatory and immune pathways. Four TRPV1-related core genes (MAPK14, GNB1, GNAQ, and ARRB2) were screened, validated by microarray dataset GSE112039 and the combined validation dataset E-GEAD-399 & 564, and verified by in vitro experiments. Our study suggested a potential crosstalk between TRPV1 and immune regulation contributing to FECD pathogenesis. The identified pivotal biomarkers and immune-related pathways provide a novel framework for future mechanistic and therapeutic studies of FECD.

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.

Gastroprotective mechanism of modified lvdou gancao decoction on ethanol-induced gastric lesions in mice: Involvement of Nrf-2/HO-1/NF-κB signaling pathway

Modified Lvdou Gancao decoction (MLG), a traditional Chinese medicine formula, has been put into clinical use to treat the diseases of the digestive system for a long run, showing great faculty in gastric protection and anti-inflammatory, whereas its protective mechanisms have not been determined. The current study puts the focus on the protective effect and its possible mechanisms of MLG on ethanol-induced gastric lesions in mice. In addition to various gastric lesion parameters and histopathology analysis, the activities of a list of relevant indicators in gastric mucosa were explored including ALDH, ADH, MDA, T-SOD, GSH-Px, and MPO, and the mechanisms were clarified using RT-qPCR, ELISA Western Blot and immunofluorescence staining. The results showed that MLG treatment induced significant increment of ADH, ALDH, T-SOD, GSH-Px, NO, PGE2 and SS activities in gastric tissues, while MPO, MDA, TNF-α and IL-1β levels were on the decline, both in a dose-dependent manner. In contrast to the model group, the mRNA expression of Nrf-2 and HO-1 in the MLG treated groups showed an upward trend while the NF-κB, TNFα, IL-1β and COX2 in the MLG treated groups had a downward trend simultaneously. Furthermore, the protein levels of p65, p-p65, IκBα, p-IκBα, iNOS, COX2 and p38 were inhibited, while Nrf2, HO-1, SOD1, SOD2 and eNOS were ramped up in MLG treatment groups. Immunofluorescence intensities of Nrf2 and HO-1 in the MLG treated groups were considerably enhanced, with p65 and IκBα diminished simultaneously, exhibiting similar trends to that of qPCR and western blot. To sum up, MLG could significantly ameliorate ethanol-induced gastric mucosal lesions in mice, which might be put down to the activation of alcohol metabolizing enzymes, attenuation of the oxidative damage and inflammatory response to maintain the gastric mucosa. The gastroprotective effect of MLG might be achieved through the diminution of damage factors and the enhancement of defensive factors involving NF-κB/Nrf2/HO-1 signaling pathway. We further confirmed that MLG has strong potential in preventing and treating ethanol-induced gastric lesions.

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.

Network Pharmacology Integrated with Transcriptomics Deciphered the Potential Mechanism of Codonopsis pilosula against Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fourth main reason of cancer-related death. Codonopsis pilosula is a commonly used traditional Chinese medicine (TCM) for patients with HCC. However, its potential mechanism for treatment of HCC remains unclear. Here, we used transcriptomics and network pharmacology to explore the potential molecular mechanisms of Codonopsis pilosula. In our study, twelve differentially expressed genes (DEGs) (5 upregulated and 7 downregulated) of Codonopsis pilosula treating HepG2 cells (a kind of HCC cell) were identified. Among the 12 DEGs, HMOX1 may play an essential role. Codonopsis pilosula mainly affects the mineral absorption pathway in HCC. We acquired 2957, 1877, and 255 targets from TCMID, SymMap, and TCMSP, respectively. Codonopsis pilosula could upregulate HMOX1 via luteolin, capsaicin, and sulforaphane. Our study provided new understanding of the potential pharmacological mechanisms of Codonopsis pilosula in treating HCC and pointed out a direction for further experimental research.

Malvidin Protects against and Repairs Peptic Ulcers in Mice by Alleviating Oxidative Stress and Inflammation

Peptic ulcer episodes cause damage to the stomach and intestine, with inflammatory cell infiltration and oxidative stress as the main players. In this study, we investigated the potential of anthocyanidin malvidin for preventive and curative peptic ulcer treatment. The anthocyanidin effects were examined in gastric ulcer mouse models induced by ethanol, non-steroidal anti-inflammatory drugs (NSAIDs), ischemia-reperfusion (IR), acetic acid and duodenal ulcer induced by polypharmacy. Expression levels of oxidative and inflammatory genes were measured to investigate the mechanism of anthocyanin activity. At a dose of 5 mg·kg⁻¹, Malvidin prevented gastric ulcer induction by ethanol, NSAID and repaired the tissue after 6 days of IR. Moreover, the anthocyanidin accelerated the healing of acetic acid-induced ulcer, increased the gene expression of EGF and COX-1, and downregulated MMP-9. Anthocyanin treatment mitigated the effect of polypharmacy on inflammation and oxidative stress observed in the intestine. Additionally, the compound downregulated cytokine expression and TLR4 and upregulated HMOX-1 and IL-10, exhibiting protective activity in the mouse gut. Malvidin thus prevented gastric and duodenal ulcers due to prominent anti-inflammatory and antioxidative effects on the gastrointestinal tract that were related to gene expression modulation and an increase in endogenous defense mechanisms.

Activation of transient receptor potential vanilloid channel 4 contributes to the development of ethanol-induced gastric injury in mice

The transient receptor potential vanilloid channel 4 (TRPV4) is associated with the development of several pathologies, particularly gastric disorders. However, there are no studies associating this receptor with the pathophysiology of gastric erosions. The aim of this study was to investigate the role of TRPV4 in the development of ethanol-induced gastric damage in vivo. Gastric lesions were induced by ethanol in Swiss mice pretreated with TRPV4 antagonists, GSK2193874 (0.1; 0.3 and 0.9 mg/kg) or Ruthenium red (0.03; 0.1 or 0.3 mg/kg) or its agonist, GSK1016790A (0.9 mg/kg). Gastric mucosal samples were taken for histopathology, immunohistochemistry, atomic force microscopy and evaluation of antioxidant parameters. The gastric mucus content and TRPV4 mRNA expression were analyzed. Ethanol exposure induced upregulation of gastric mRNA and protein expression of TRPV4. TRPV4 blockade promoted gastroprotection against ethanol-induced injury on macro- and microscopic levels, leading to reduced hemorrhage, cell loss and edema and enhanced gastric mucosal integrity. Moreover, an increase in superoxide dismutase (SOD) and glutathione (GSH) activity was observed, followed by a decrease in malondialdehyde (MDA) levels. TRPV4 blockade during alcohol challenge reestablished gastric mucus content. The combination of TRPV4 agonist and ethanol revealed macroscopic exacerbation of gastric damage area. Our results confirmed the association of TRPV4 with the development of gastric injury, showing the importance of this receptor for further investigations in the field of gastrointestinal pathophysiology and pharmacology.

Updated Role of Neuropeptide Y in Nicotine-Induced Endothelial Dysfunction and Atherosclerosis

Cardiovascular disease is the leading cause of death worldwide. Endothelial dysfunction of the arterial vasculature plays a pivotal role in cardiovascular pathogenesis. Nicotine-induced endothelial dysfunction substantially contributes to the development of arteriosclerotic cardiovascular disease. Nicotine promotes oxidative inflammation, thrombosis, pathological angiogenesis, and vasoconstriction, and induces insulin resistance. However, the exact mechanism through which nicotine induces endothelial dysfunction remains unclear. Neuropeptide Y (NPY) is widely distributed in the central nervous system and peripheral tissues, and it participates in the pathogenesis of atherosclerosis by regulating vasoconstriction, energy metabolism, local plaque inflammatory response, activation and aggregation of platelets, and stress and anxiety-related emotion. Nicotine can increase the expression of NPY, suggesting that NPY is involved in nicotine-induced endothelial dysfunction. Herein, we present an updated review of the possible mechanisms of nicotine-induced atherosclerosis, with a focus on endothelial cell dysfunction associated with nicotine and NPY.

Role of Carbon Monoxide in Host-Gut Microbiome Communication

Nature is full of examples of symbiotic relationships. The critical symbiotic relation between host and mutualistic bacteria is attracting increasing attention to the degree that the gut microbiome is proposed by some as a new organ system. The microbiome exerts its systemic effect through a diverse range of metabolites, which include gaseous molecules such as H₂, CO₂, NH₃, CH₄, NO, H₂S, and CO. In turn, the human host can influence the microbiome through these gaseous molecules as well in a reciprocal manner. Among these gaseous molecules, NO, H₂S, and CO occupy a special place because of their widely known physiological functions in the host and their overlap and similarity in both targets and functions. The roles that NO and H₂S play have been extensively examined by others. Herein, the roles of CO in host-gut microbiome communication are examined through a discussion of (1) host production and function of CO, (2) available CO donors as research tools, (3) CO production from diet and bacterial sources, (4) effect of CO on bacteria including CO sensing, and (5) gut microbiome production of CO. There is a large amount of literature suggesting the "messenger" role of CO in host-gut microbiome communication. However, much more work is needed to begin achieving a systematic understanding of this issue.

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.

Cytoprotective and antisecretory properties of methanolic extract of Distemonanthus benthamianus (Caesalpiniaceae) stem bark on acute gastric ulcer in rats

OBJECTIVES

In African traditional medicine, Distemonanthus benthamianus (Caesalpiniaceae) is used to treat many diseases including gastric ulcers. We evaluated in this study, the cytoprotective and antisecretory properties of the methanolic extract of the stem bark of this plant using different technics of gastric lesion induction.

METHODS

Cytoprotective and antisecretory activity of the methanolic extract of D. benthamianus stem bark was evolved through six methods of gastric lesion induction in experimental Wistar male rats (150-200 g): (1) gastric lesions induced by HCl/ethanol, (2) gastric lesions induced by Indomethacin- HCl/ethanol, (3) gastric lesion induced by Indomethacin, (4) gastric lesions induced by Pylorus ligation, (5) gastric lesions induced by histamine-Pylorus ligation, (6) gastric lesions induced by carbachol-Pylorus ligation. Mucus and gastric mucosal ulceration were evaluated. pH, gastric volume, and acidity were quantified in all pylorus ligation induction technics. Nitric oxide (NO) level was determined in indomethacin induced gastric ulcers.

RESULTS

At different doses (125, 250 and 500 mg/kg), extract reduced significantly the ulcer index. In all models used, that is 100.00% with HCl/ethanol; 100.00% with HCl/ethanol/indomethacin; 95.70% with Indomethacin; 74.79% with pylorus ligation, 95.94% histamine-Pylorus ligation, 99.54% carbachol-Pylorus ligation at the highest dose of 500 mg/kg. The lesion formation reduces in all the methods used followed by a significant increase of mucus production. The pylorus ligation technic revealed that the extract has an antisecretory activity.

CONCLUSIONS

The methanolic extract of D. benthamianus stem bark has both cytoprotective and antisecretory effects. This extract exerts its antisecretory effect trough cholinergic and histaminergic pathways.

Evidence for Cytoprotective Effect of Carbon Monoxide Donor in the Development of Acute Esophagitis Leading to Acute Esophageal Epithelium Lesions

Exposure to acidic gastric content due to malfunction of lower esophageal sphincter leads to acute reflux esophagitis (RE) leading to disruption of esophageal epithelial cells. Carbon monoxide (CO) produced by heme oxygenase (HMOX) activity or released from its donor, tricarbonyldichlororuthenium (II) dimer (CORM-2) was reported to protect gastric mucosa against acid-dependent non-steroidal anti-inflammatory drug-induced damage. Thus, we aimed to investigate if CO affects RE-induced esophageal epithelium lesions development. RE induced in Wistar rats by the ligation of a junction between pylorus and forestomach were pretreated i.g. with vehicle CORM-2; RuCl₃; zinc protoporphyrin IX, or hemin. CORM-2 was combined with NG-nitro-L-arginine (L-NNA), indomethacin, capsazepine, or capsaicin-induced sensory nerve ablation. Esophageal lesion score (ELS), esophageal blood flow (EBF), and mucus production were determined by planimetry, laser flowmetry, histology. Esophageal Nrf-2, HMOXs, COXs, NOSs, TNF-α and its receptor, IL-1 family and IL-1 receptor antagonist (RA), NF-κB, HIF-1α, annexin-A1, suppressor of cytokine signaling (SOCS3), TRPV1, c-Jun, c-Fos mRNA/protein expressions, PGE₂, 8-hydroxy-deoxyguanozine (8-OHdG) and serum COHb, TGF-β1, TGF-β2, IL-1β, and IL-6 content were assessed by PCR, immunoblotting, immunohistochemistry, gas chromatography, ELISA or Luminex platform. Hemin or CORM-2 alone or combined with L-NNA or indomethacin decreased ELS. Capsazepine or capsaicin-induced denervation reversed CORM-2 effects. COHb blood content, esophageal HMOX-1, Nrf-2, TRPV1 protein, annexin-A1, HIF-1α, IL-1 family, NF-κB, c-Jun, c-Fos, SOCS3 mRNA expressions, and 8-OHdG levels were elevated while PGE₂ concentration was decreased after RE. CO donor-maintained elevated mucosal TRPV1 protein, HIF-1 α, annexin-A1, IL-1RA, SOCS3 mRNA expression, or TGF-β serum content, decreasing 8-OHdG level, and particular inflammatory markers expression/concentration. CORM-2 and Nrf-2/HMOX-1/CO pathway prevent esophageal mucosa against RE-induced lesions, DNA oxidation, and inflammatory response involving HIF-1α, annexin-A1, SOCS3, IL-1RA, TGF-β-modulated pathways. Esophagoprotective and hyperemic CO effects are in part mediated by afferent sensory neurons and TRPV1 receptors activity with questionable COX/PGE₂ or NO/NOS systems involvement.

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.

Curcumin: A Potent Protectant against Esophageal and Gastric Disorders

Turmeric obtained from the rhizomes of Curcuma longa has been used in the prevention and treatment of many diseases since the ancient times. Curcumin is the principal polyphenol isolated from turmeric, which exhibits anti-inflammatory, antioxidant, antiapoptotic, antitumor, and antimetastatic activities. The existing evidence indicates that curcumin can exert a wide range of beneficial pleiotropic properties in the gastrointestinal tract, such as protection against reflux esophagitis, Barrett’s esophagus, and gastric mucosal damage induced by nonsteroidal anti-inflammatory drugs (NSAIDs) and necrotizing agents. The role of curcumin as an adjuvant in the treatment of a Helicobacter pylori infection in experimental animals and humans has recently been proposed. The evidence that this turmeric derivative inhibits the invasion and proliferation of gastric cancer cells is encouraging and warrants further experimental and clinical studies with newer formulations to support the inclusion of curcumin in cancer therapy regimens. This review was designed to analyze the existing data from in vitro and in vivo animal and human studies in order to highlight the mechanisms of therapeutic efficacy of curcumin in the protection and ulcer healing of the upper gastrointestinal tract, with a major focus on addressing the protection of the esophagus and stomach by this emerging compound.

Immune aspects of the bi-directional neuroimmune facilitator TRPV1

A rapidly growing area of interest in biomedical science involves the reciprocal crosstalk between the sensory nervous and immune systems. Both of these systems are highly integrated, detecting potential environmental harms and restoring homeostasis. Many different cytokines, receptors, neuropeptides, and other proteins are involved in this bidirectional communication that are common to both systems. One such family of proteins includes the transient receptor potential vanilloid (TRPV) proteins. Though much progress has been made in understanding TRPV proteins in the nervous system, their functions in the immune system are not well elucidated. Hence, further understanding their role in the peripheral immune system and as regulators of neuroimmunity is critical for evaluating their potential as therapeutic targets for numerous inflammatory disorders, cancers, and other disease states. Here, we focus on the latest advancements in understanding TRPV1 and TRPV2's roles in the immune system, TRPV1 in neuroimmunity, and TRPV1's potential involvement in anti-tumor therapy.