Hydrogen-rich saline attenuates acute renal injury in sodium taurocholate-induced severe acute pancreatitis by inhibiting ROS and NF-κB pathway

The role of mitochondrial damage-associated molecular patterns in acute pancreatitis

Acute pancreatitis (AP) is one of the most common gastrointestinal tract diseases with significant morbidity and mortality. Current treatments remain unspecific and supportive due to the severity and clinical course of AP, which can fluctuate rapidly and unpredictably. Mitochondria, cellular power plant to produce energy, are involved in a variety of physiological or pathological activities in human body. There is a growing evidence indicating that mitochondria damage-associated molecular patterns (mtDAMPs) play an important role in pathogenesis and progression of AP. With the pro-inflammatory properties, released mtDAMPs may damage pancreatic cells by binding with receptors, activating downstream molecules and releasing inflammatory factors. This review focuses on the possible interaction between AP and mtDAMPs, which include cytochrome c (Cyt c), mitochondrial transcription factor A (TFAM), mitochondrial DNA (mtDNA), cardiolipin (CL), adenosine triphosphate (ATP) and succinate, with focus on experimental research and potential therapeutic targets in clinical practice. Preventing or diminishing the release of mtDAMPs or targeting the mtDAMPs receptors might have a role in AP progression.

Application of Electrolyzed Hydrogen Water for Management of Chronic Kidney Disease and Dialysis Treatment-Perspective View

Chronic kidney disease (CKD), which is globally on the rise, has become an urgent challenge from the perspective of public health, given its risk factors such as end-stage renal failure, cardiovascular diseases, and infections. The pathophysiology of CKD, including dialysis patients, is deeply associated with enhanced oxidative stress in both the kidneys and the entire body. Therefore, the introduction of a safe and widely applicable antioxidant therapy is expected as a measure against CKD. Electrolyzed hydrogen water (EHW) generated through the electrolysis of water has been confirmed to possess chemical antioxidant capabilities. In Japan, devices producing this water have become popular for household drinking water. In CKD model experiments conducted to date, drinking EHW has been shown to suppress the progression of kidney damage related to hypertension. Furthermore, clinical studies have reported that systemic oxidative stress in patients undergoing dialysis treatment using EHW is suppressed, leading to a reduction in the incidence of cardiovascular complications. In the future, considering EHW as one of the comprehensive measures against CKD holds significant importance. The medical utility of EHW is believed to be substantial, and further investigation is warranted.

Hydrogen: A Rising Star in Gas Medicine as a Mitochondria-Targeting Nutrient via Activating Keap1-Nrf2 Antioxidant System

The gas molecules O2, NO, H2S, CO, and CH4, have been increasingly used for medical purposes. Other than these gas molecules, H2 is the smallest diatomic molecule in nature and has become a rising star in gas medicine in the past few decades. As a non-toxic and easily accessible gas, H2 has shown preventive and therapeutic effects on various diseases of the respiratory, cardiovascular, central nervous system, and other systems, but the mechanisms are still unclear and even controversial, especially the mechanism of H2 as a selective radical scavenger. Mitochondria are the main organelles regulating energy metabolism in living organisms as well as the main organelle of reactive oxygen species' generation and targeting. We propose that the protective role of H2 may be mainly dependent on its unique ability to penetrate every aspect of cells to regulate mitochondrial homeostasis by activating the Keap1-Nrf2 phase II antioxidant system rather than its direct free radical scavenging activity. In this review, we summarize the protective effects and focus on the mechanism of H2 as a mitochondria-targeting nutrient by activating the Keap1-Nrf2 system in different disease models. In addition, we wish to provide a more rational theoretical support for the medical applications of hydrogen.

Clinical Use and Treatment Mechanism of Molecular Hydrogen in the Treatment of Various Kidney Diseases including Diabetic Kidney Disease

As diabetes rates surge globally, there is a corresponding rise in the number of patients suffering from diabetic kidney disease (DKD), a common complication of diabetes. DKD is a significant contributor to chronic kidney disease, often leading to end-stage renal failure. However, the effectiveness of current medical treatments for DKD leaves much to be desired. Molecular hydrogen (H2) is an antioxidant that selectively reduces hydroxyl radicals, a reactive oxygen species with a very potent oxidative capacity. Recent studies have demonstrated that H2 not only possesses antioxidant properties but also exhibits anti-inflammatory effects, regulates cell lethality, and modulates signal transduction. Consequently, it is now being utilized in clinical applications. Many factors contribute to the onset and progression of DKD, with mitochondrial dysfunction, oxidative stress, and inflammation being strongly implicated. Recent preclinical and clinical trials reported that substances with antioxidant properties may slow the progression of DKD. Hence, we undertook a comprehensive review of the literature focusing on animal models and human clinical trials where H2 demonstrated effectiveness against a variety of renal diseases. The collective evidence from this literature review, along with our previous findings, suggests that H2 may have therapeutic benefits for patients with DKD by enhancing mitochondrial function. To substantiate these findings, future large-scale clinical studies are needed.

Fluorescent intracellular imaging of reactive oxygen species and pH levels moderated by a hydrogenase mimic in living cells

The catalytic generation of H₂ in living cells provides a method for antioxidant therapy. In this study, an [FeFe]-hydrogenase mimic [Ru + Fe₂S₂@F127(80)] was synthesized by self-assembling polymeric pluronic F-127, catalytic [Fe₂S₂] sites, and photosensitizer Ru(bpy)₃²⁺. Under blue light irradiation, hydrated protons were photochemically reduced to H₂, which increased the local pH in living cells (HeLa cells). The generated H₂ was subsequently used as an antioxidant to decrease reactive oxygen species (ROS) levels in living cells (HEK 293T, HepG2, MCF-7, and HeLa cells). Our findings revealed that the proliferation of HEK 293T cells increased by a factor of about six times, relative to that of other cells (HepG2, MCF-7, and HeLa cells). Intracellular ROS and pH levels were then monitored using fluorescent cell imaging. Our study showed that cell imaging can be used to evaluate the ability of Ru + Fe₂S₂@F127 to eliminate oxidative stress and prevent ROS-related diseases.

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An [FeFe]-hydrogenase mimic was synthesized for H₂ photogeneration.

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The catalytic generation of H₂ was evaluated in HEK 293T cells.

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The H₂ generated by Ru + Fe₂S₂@F127(80) was able to decrease ROS levels.

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Light irradiation of Ru + Fe₂S₂@F127(80) led to an increase in intracellular pH.

Hydrogen: A Novel Treatment Strategy in Kidney Disease

BACKGROUND

Hydrogen is a chemical substance that has yet to be widely used in medicine. However, recent evidence indicates that hydrogen has multi-faceted pharmacological effects such as antioxidant, anti-inflammatory, and antiapoptotic properties. An increased number of studies are being conducted on the application of hydrogen in various diseases, especially those affecting the renal system.

SUMMARY

Hydrogen can be inhaled, as a gas or liquid, and can be administered orally, intravenously, or locally. Hydrogen can rapidly enter suborganelles such as mitochondria and nucleus by simple diffusion, producing reactive oxygen species (ROS) and triggering DNA damage. Hydrogen can selectively scavenge hydroxyl radical (•OH) and peroxynitrite (ONOO^-), but not other reactive oxygen radicals with physiological functions, such as peroxyanion (O₂^-) and hydrogen peroxide (H₂O₂). Although the regulatory effect of hydrogen on the signal transduction pathway has been confirmed, the specific mechanism of its influence on signal molecules remains unknown. Although many studies have investigated the therapeutic and preventive effects of H₂ in cellular and animal experiments, clinical trials are few and still far behind. As a result, more clinical trials are required to investigate the role of hydrogen in kidney disease, as well as the effect of its dose, timing, and form on the overall efficacy. Large-scale randomized controlled clinical trials will be required before hydrogen can be used to treat renal illnesses.

KEY MESSAGES

This article reviews the mechanisms of hydrogen in the treatment of renal disease and explores the possibilities of its use in clinical practice.

Inhibition of the p38 MAPK pathway attenuates renal injury in pregnant rats with acute necrotizing pancreatitis

The p38 mitogen-activated protein kinase (MAPK) pathway is an important intracellular signalling pathway that leads to increased expression of pro-inflammatory mediators. Our previous studies have shown that the p38 MAPK pathway was changed in the acute renal injury (ARI) in acute pancreatitis in late pregnancy (APIP), whereas the role of p38 MAPK in APIP-induced ARI has been poorly understood. The present study was undertaken to investigate the participation of the p38 MAPK signalling pathway and the protective effect of SB203580, an inhibitor of p38 MAPK in ARI in APIP. Twenty-four late-gestation SD rats were randomly assigned to four groups: the normal group (N), sham-operated group (SO), acute necrotizing pancreatitis (ANP) group, and p38 MAPK inhibitor (SB203580) treatment group (T). The results showed that serum amylase, lipase, urea, and creatinine levels of p38 inhibitor of T groups were markedly lower than the ANP groups. Additionally, the expression of phosphorylated p38 and myeloperoxidase (MPO), tumour necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-6, nuclear factor kappa-B (NF-κB), caspase-3, and terminal deoxynucleotidyl TUNEL-positive cells was markedly lower in the T group than in the ANP group. Our results suggest that SB203580 can inhibit renal injury by inhibiting the P38 MAPK signalling pathway and blocking the inflammatory responses in APIP.

Direct Targets and Subsequent Pathways for Molecular Hydrogen to Exert Multiple Functions: Focusing on Interventions in Radical Reactions

Molecular hydrogen (H₂) was long regarded as non-functional in mammalian cells. We overturned the concept by demonstrating that H₂ exhibits antioxidant effects and protects cells against oxidative stress. Subsequently, it has been revealed that H₂ has multiple functions in addition to antioxidant effects, including antiinflammatory, anti-allergic functions, and as cell death and autophagy regulation. Additionally, H₂ stimulates energy metabolism. As H₂ does not readily react with most biomolecules without a catalyst, it is essential to identify the primary targets with which H₂ reacts or interacts directly. As a first event, H₂ may react directly with strong oxidants, such as hydroxyl radicals (•OH) in vivo. This review addresses the key issues related to this in vivo reaction. •OH may have a physiological role because it triggers a free radical chain reaction and may be involved in the regulation of Ca2+- or mitochondrial ATP-dependent K+-channeling. In the subsequent pathway, H₂ suppressed a free radical chain reaction, leading to decreases in lipid peroxide and its end products. Derived from the peroxides, 4-hydroxy-2-nonenal functions as a mediator that up-regulates multiple functional PGC-1α. As the other direct target in vitro and in vivo, H₂ intervenes in the free radical chain reaction to modify oxidized phospholipids, which may act as an antagonist of Ca2+-channels. The resulting suppression of Ca2+-signaling inactivates multiple functional NFAT and CREB transcription factors, which may explain H₂ multi-functionality. This review also addresses the involvement of NFAT in the beneficial role of H₂ in COVID-19, Alzheimer's disease and advanced cancer. We discuss some unsolved issues of H₂ action on lipopolysaccharide signaling, MAPK and NF-κB pathways and the Nrf2 paradox. Finally, as a novel idea for the direct targeting of H2, this review introduces the possibility that H₂ causes structural changes in proteins via hydrate water changes.

Hydrogen Promotes the M1 Macrophage Conversion During the Polarization of Macrophages in Necrotizing Enterocolitis

Background: Hydrogen is protective against intestinal injury in necrotizing enterocolitis (NEC), mainly through to alleviate inflammation response. The M1 macrophages can promote inflammation. We hypothesized that hydrogen would promote the M1 macrophages conversion during the polarization and reduce the inflammatory factors in NEC. Methods: We used M1 and M2 macrophages induced from RAW264.7 cells and bone marrow-derived macrophages, models of NEC and macrophages derived from spleens, abdominal lymph nodes and lamina propria in model mice. Cytokines, CD16/32 and CD206 were measured by quantitative PCR, flow cytometry. Nuclear factor-κB (NF-κB) p65 were determined by western blot. Histology staining were used to assess the severity of NEC. Results: Macrophages were successfully polarized to M1 or M2 by assessing the expression of inflammatory factors. Pro-inflammatory factors and CD16/32 in M1 macrophages were decreased, and the expression of CD16/32 in lamina propria were inhibited after treatment with hydrogen, but the changes has no effects in other tissues. Hydrogen inhibited the NF-κB p65 in M1 macrophages nucleus and distal ileum of NEC. HE staining showed hydrogen could attenuate the severity of NEC. Conclusion: Hydrogen could attenuate the severity of NEC through promoting M1 macrophages conversion by inhibited the expression of NF-κB p65 in the nucleus.

Recent advances in studies of molecular hydrogen in the treatment of pancreatitis

Pancreatitis is an inflammatory disease of the pancreas characterized by acinar cell injury and is associated with the abnormal release of trypsin, which results in high mortality due to systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). The inflammatory response, impaired autophagic flux, endoplasmic reticulum stress (ERS) and their interactions are involved in the development of pancreatitis. Molecular hydrogen (H₂) is a novel antioxidant that possesses the features of selective scavenging of oxygen free radicals and nontoxic metabolites and has been shown to be efficacious for treating infection, injury, tumors, ischemia-reperfusion organ injury, metabolic disease and several other diseases. Recent studies have found that H₂ is also useful in the treatment of pancreatitis, which may be related to the mechanism of antioxidative stress, anti-inflammation, anti-apoptosis, regulation of immunity and regulation of molecular pathways. This review focuses on the pathogenesis of pancreatitis and the research progress and potential mechanisms of H₂ against pancreatitis to provide theoretical bases for future research and clinical application of H₂ therapy for pancreatitis.

Hydrogen: A Novel Option in Human Disease Treatment

H₂ has shown anti-inflammatory and antioxidant ability in many clinical trials, and its application is recommended in the latest Chinese novel coronavirus pneumonia (NCP) treatment guidelines. Clinical experiments have revealed the surprising finding that H₂ gas may protect the lungs and extrapulmonary organs from pathological stimuli in NCP patients. The potential mechanisms underlying the action of H₂ gas are not clear. H₂ gas may regulate the anti-inflammatory and antioxidant activity, mitochondrial energy metabolism, endoplasmic reticulum stress, the immune system, and cell death (apoptosis, autophagy, pyroptosis, ferroptosis, and circadian clock, among others) and has therapeutic potential for many systemic diseases. This paper reviews the basic research and the latest clinical applications of H₂ gas in multiorgan system diseases to establish strategies for the clinical treatment for various diseases.

Molecular hydrogen: A potential radioprotective agent

In recent years, many studies have shown that hydrogen has therapeutic and preventive effects on various diseases. Its selective antioxidant properties were well noticed. Most of the ionizing radiation-induced damage is caused by hydroxyl radicals (OH) from radiolysis of H₂O. Since hydrogen can mitigate such damage through multiple mechanisms, it presents noteworthy potential as a novel radio-protective agent. This review analyses possible mechanisms for hydrogen's radioprotective properties and effective delivery methods. We also look into details of vitro and vivo studies for hydrogen's radioprotective effects, and clinical practices. We conclude that hydrogen has good potential in radio-protection, with evidence that warrants greater research efforts in this field.

Emodin Attenuates Severe Acute Pancreatitis via Antioxidant and Anti-inflammatory Activity

There is no specific drug to treat severe acute pancreatitis (SAP), which induces substantial medical and social burden. Many studies have reported the beneficial effects of emodin against SAP in vivo and in vitro. However, the underlying mechanism has been unclear. This paper described the design and implementation of anti-inflammatory and antioxidant activity of emodin. Emodin restored the pathological damage of SAP and simultaneously decreased the high levels of serum amylase, lipase, TNF-α, and IL-18 in the peripheral blood of SAP rat. Emodin reversed reactive oxygen species (ROS) in neutrophils derived from SAP rat. The levels of voltage-dependent anion channel 1 (VDAC1), NOD-like receptor protein 3 (NLRP3), caspase-1, and IL-18 were examined to analyze the change of inflammasome-related mediators between SAP and emodin treatment. These findings suggest that emodin plays its protective role on SAP against oxidative stress and inflammasome signals.

Picroside II Improves Severe Acute Pancreatitis-Induced Intestinal Barrier Injury by Inactivating Oxidative and Inflammatory TLR4-Dependent PI3K/AKT/NF-κB Signaling and Improving Gut Microbiota

Background

Picroside II exerts anti-inflammatory and antidiarrheal effects for treating the diseases associated with oxidative injury. However, its function on pancreatitis-induced intestinal barrier injury remains unclear. Hypothesis/Purpose. We hypothesized that picroside II will have protective effects against pancreatitis-induced intestinal barrier injury by affecting oxidative and inflammatory signaling (Toll-like receptor 4- (TLR4-) dependent phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and nuclear factor kappa B (NF-κB)). Study Design and Methods. A Sprague-Dawley (SD) rat model with severe acute pancreatitis (SAP) was induced via the injection of sodium taurocholate (4% wt/vol; 1 mL/kg). All rats were divided into 3 groups: sham (CG), SAP-induced intestinal barrier injury (MG), and picroside II (PG) groups. Intestinal barrier injury was assessed by scanning electron microscopy (SEM), hematoxylin and eosin staining, and pathological scores. We measured the levels of pancreatitis biomarkers (amylase and lipase), oxidative and inflammatory signaling (TLR4-dependent PI3K/AKT/NF-κB), oxidative stress marker (superoxidase dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx), and malondialdehyde), and inflammatory markers (tumor necrosis factor α (TNFα), interleukin- (IL-) 1, IL-6, and IL-10) in serum and/or gut tissues. Gut microbiota composition in feces was measured by using 16S rRNA sequencing.

Results

SEM showed that intestinal barrier injury was caused with the loss of intestinal villi and mitochondria destruction, and pathological scores were increased in the MG group. The levels of amylase, lipase, malondialdehyde, TNFα, IL-1, IL-6, TLR4, PI3K, AKT, and NF-κB were increased, and the levels of SOD, GPx, CAT, and IL-10 was reduced in the MG group when compared with CG group (P < 0.05). Picroside II treatment inhibited the symptoms in the MG group and showed antioxidant and anti-inflammatory activities. The serum levels of picroside II had strong correlation with the levels of inflammatory and oxidative stress biomarkers (P < 0.05). Picroside II treatment increased the proportion of Lactobacillus and Prevotella and decreased the proportion of Helicobacter and Escherichia_Shigella in the model.

Conclusions

Picroside II improved the SAP-induced intestinal barrier injury in the rat model by inactivating oxidant and inflammatory signaling and improving gut microbiota.

Saikosaponin a attenuates hyperlipidemic pancreatitis in rats via the PPAR-γ/NF-κB signaling pathway

The therapeutic effect of saikosaponin a (SSa) on hyperlipidemic pancreatitis (HP) is not completely understood. The aim of the present study was to investigate the therapeutic effect and the underlying mechanism of SSa using a rat model of HP. Following successful establishment of the HP rat model, different doses of SSa (low dose group, 10 mg/kg or high dose group, 20 mg/kg) were administrated. Histopathological examination, the wet/dry (W/D) ratio and myeloperoxidase (MPO) activity of the pancreatic tissues were assessed. The lipid, amylase (AMY), lipase and proinflammatory cytokine profiles in serum, as well as the expression of peroxisome proliferator-activated receptor (PPAR)-γ and the NF-κB signaling pathway-related proteins in pancreatic tissues were evaluated. The results showed that SSa effectively attenuated pancreatic pathological injury and reduced both the W/D ratio and MPO activity compared to the HP model rats. SSa also improved lipid metabolism by significantly decreasing the serum levels of total cholesterol and triglycerides (P<0.05). Following the administration of SSa, the activity of AMY and lipase, as well as the levels of the proinflammatory cytokines tumor necrosis factor-α, interleukin (IL)-1β and IL-6 were reduced, particularly in the high dosage group (P<0.05). Furthermore, SSa activated PPAR-γ expression and suppressed the NF-κB signaling pathway in pancreatic tissues. The present study suggested that SSa attenuated HP in rats by increasing lipid metabolism and inhibiting the release of proinflammatory cytokines via the NF-κB inflammatory pathway. The results from the present study indicated that SSa might be a promising therapeutic agent for the treatment of HP.

Sirt3 mediates the protective effect of hydrogen in inhibiting ROS-induced retinal senescence

Hydrogen possesses antioxidative effects and cures numerous types of ophthalmopathy, but the mechanism of hydrogen on ROS-induced retinal senescence remains elusive. In this study, retinal morphology revealed that hydrogen reduced the number and size of vitreous black deposits in Bruch's membrane in NaIO3 mice. Hydrogen also reduced ROS levels in the retina as assessed by DHE staining. Moreover, this result was consistent with the downregulation of expression of the oxidative stress hallmark OGG1. These findings suggested that hydrogen can reduce retinal oxidative stress induced by NaIO3, and this result was further verified using the antioxidant ALCAR. Mechanistic analysis revealed that hydrogen significantly inhibited the downregulation of Sirt3 expression, and this notion was confirmed using AICAR, which restores Sirt3 expression and activity. Moreover, hydrogen reduced the expression of p53, p21 and p16 and the number of blue-green precipitations in the retinas of NaIO3 mice as assessed by SA-β-gal staining. We also found that hydrogen decreased the expression of the DNA damage-related protein ATM, cyclinD1 and NF-κB but increased the expression of the DNA repair-related protein HMGB1, suggesting that hydrogen inhibits senescence in retinas of NaIO3 mice. Additionally, OCT examination revealed that hydrogen suppressed retinal high reflex formation significantly and prevented the retina from thinning. This result was supported by ERG assays that demonstrated that hydrogen prevented the reduction in a- and b-wave amplitude induced by NaIO3 in mice. Thus, our data suggest that hydrogen may inhibit retinal senescence by suppressing the downregulation of Sirt3 expression through reduced oxidative stress reactions.

Hydrogen-rich saline protects against hepatic injury induced by ischemia-reperfusion and laparoscopic hepatectomy in swine

BACKGROUND

Hydrogen-rich saline (HRS) has antioxidative, anti-inflammatory and anti-apoptotic properties. We investigated the effects of hydrogen on hepatic ischemia-reperfusion (I/R) and laparoscopic hepatectomy in swine.

METHODS

Twenty-one healthy Bama miniature pigs were randomly divided into the sham group, ischemia-reperfusion injury (IRI) group, HRS-5 (5 mL/kg) group, and HRS-10 (10 mL/kg) group. HRS was injected through the portal vein 10 min before reperfusion and at postoperative day 1, 2 and 3. The roles of HRS on oxidative stress, inflammatory response and liver regeneration were studied.

RESULTS

Compared with the IRI group, HRS treatment attenuated oxidative stress by increasing catalase activity and reducing myeloperoxidase. White blood cells in the HRS-10 group were reduced compared with the IRI group (P < 0.01). In the HRS-10 group, interleukin-1 beta, interleukin-6 and tumor necrosis factor alpha, C-reactive protein and cortisol were downregulated, whereas interleukin-10 was upregulated. In addition, HRS attenuated endothelial cell injury and promoted the secretion of angiogenic cytokines, including vascular endothelial growth factor, angiopoietin-1 and angiopoietin-2. HRS elevated the levels of hepatocyte growth factor, Cyclin D1, proliferating cell nuclear antigen, Ki-67 and reduced the secretion of transforming growth factor-beta.

CONCLUSIONS

HRS treatment may exert a protective effect against I/R and hepatectomy-induced hepatic damage by reducing oxidative stress, suppressing the inflammatory response and promoting liver regeneration.

Inhibition of endoplasmic reticulum stress by 4-phenylbutyric acid prevents vital organ injury in rat acute pancreatitis

This study was conducted to investigate the effect of 4-phenylbutyric acid (4-PBA) on vital organ injury following sodium taurocholate-induced acute pancreatitis (AP) in rats and the pertinent mechanism. The serum biochemical indicators and key inflammatory cytokines, histopathological damage and apoptosis of vital organs in rat AP, were evaluated in the presence or absence of 4-PBA. Moreover, mRNA and protein levels of endoplasmic reticulum stress (ERS) markers were assessed. 4-PBA significantly attenuated the structural and functional damage of vital organs, including serum pancreatic enzymes, hepatic enzymes, creatinine, and urea. The morphological changes and infiltration of neutrophils and macrophages were reduced as well. These effects were accompanied by decreased serum levels of proinflammatory TNF-α and IL-1β. Furthermore, 4-PBA diminished the expression of ERS markers (glucose-regulated protein 78, CCAAT/enhancer-binding protein homologous protein, protein kinase R-like ER kinase, activated transcription factor 6, and type-1 inositol requiring enzyme) in vital organs of AP rats. 4-PBA also reduced AP-induced apoptosis in lung, liver, and kidney tissues as shown by TUNEL assay. The present study demonstrated that 4-PBA protected pancreas, lung, liver, and kidney from injury in rat AP by regulating ERS and mitigating inflammatory response to restrain cell death and further suggested that 4-PBA may have potential therapeutic implications in the disease. NEW & NOTEWORTHY In this study, we suggest that endoplasmic reticulum stress (ERS) is an important player in the development of acute pancreatitis-induced multiorgan injury, providing additional evidence for the proinflammatory role of ERS. Because 4-phenylbutyric acid has been suggested to inhibit ERS in many pathological conditions, it is possible that this effect can be involved in alleviating inflammatory response and cell death to ameliorate vital organ damage following acute pancreatitis induced by sodium taurocholate in rats.

A Novel Derivative of the Natural Product Danshensu Suppresses Inflammatory Responses to Alleviate Caerulein-Induced Acute Pancreatitis

Acute pancreatitis (AP), a common abdominal inflammatory disorder, is characterized by premature intracellular activation of digestive proteases within pancreatic acini and a consecutive systemic inflammatory response. Although the mechanism remains to be fully understood, inflammation is the main cause of pancreatic damage in AP. A novel compound [4-(2-acetoxy-3-((R)-3-(benzylthio)-1-methoxy-1-oxopropan-2-ylamino)-3-oxopropyl)-1,2-phenylene diacetate (DSC)], derived from danshensu, exhibits anti-inflammatory and anti-apoptotic properties in vitro. However, its potential beneficial effect in AP has not been demonstrated. This study aimed to investigate the effects and underlying mechanisms of DSC in experimental AP in mice. We found that DSC suppressed inflammatory responses in AP by inhibiting the activation of nuclear factor-κB (NF-κB), signal transducer and activator of transcription 3 (STAT3) and nucleotide-binding domain leucine-rich repeat containing family, pyrin domain-containing 3 (NLRP3) inflammasome. Furthermore, treatment with DSC modulated the infiltration of neutrophils and the phenotypes of macrophages in mice induced with AP. Interestingly, we found that the expression of nuclear factor-erythroid 2 related factor 2 (Nrf2) and its regulated antioxidant enzyme heme oxygenase-1 (HO-1), which modulate inflammatory activities, was significantly increased in DSC-treated groups. Together, our findings demonstrate that DSC alleviates pancreatic inflammation and damage in AP by inhibiting the activation of NF-κB, STAT3, and NLRP3 inflammasome and modulating immune cell responses.

The toxicity and efficacy evaluation of different fractions of Kansui fry-baked with vinegar on Walker-256 tumor-bearing malignant ascites effusion rats and normal rats

ETHNOPHARMACOLOGICAL RELEVANCE

Kansui, the root of Euphorbia kansui S.L.Liou ex S.B.Ho (E.kansui), is a classical traditional Chinese medicine (TCM) with certain toxicity. According to the theory of TCM, kansui fry-baked wtith vinegar (VEK) possesses low toxicity and mild diuretic and purgative efficacy. In clinical practice, it is commonly used for the treatmtablent of ascites and oliguria. The present study aimed to evaluate the toxicity and efficacy of different fractions of VEK and reveal the underlying material basis by employing an animal model of malignant ascites effusion (MAE) in rats.

MATERIALS AND METHODSTA

The MAE rats as the model were constructed in SPF male wistar rats by intraperitoneal injection of Walker-256 tumor cells. The MAE rats were used and randomly divided into the control group (normal rats), control groups with different fractions (VEKA, VEKB, VEKC and VEKD), model group (MAE rats), positive control group (model group with furosemide), model groups with different fractions (VEKA, VEKB, VEKC and VEKD). Histopathological observation was used to confirm Walker-256 tumor-bearing organ injuries in rats. For the efficacy evaluation, the ascites and urine volumes, the urinary electrolyte concentrations (Na⁺, K⁺ and Cl^-) and pH, the ascites levels of pro-inflammatory cytokines (IL-2, IL-6, TNF-α, IFN-γ and VEGF), PRA, the serum levels of Ang II, ALD and ADH, as well as AQP8 protein expression in the gastrointestinal tract were detected. Furthermore, different levels of indicators were measured in the toxicity evaluation of different fractions both on normal and model rats, including serum liver enzymes (AST and ALT), serum oxidative damage parameters (GSH, MDA, LDH and SOD), expressions of inflammatory parameters (NF-κB, ICAM-1 and E-cadherin) and apoptosis signals (caspase-3, -8, -9, Bcl-2 and Bax) in the liver and gastrointestinal tract.

RESULTS

Walker-256 tumor-bearing malignant ascites effusion rats showed obvious hepatic and gastrointestinal injuries by histopathological observation. In the efficacy evaluation, model rats treated with VEKB and VEKC showed significant urine increase (VEKB, P < 0.01; VEKC, P < 0.01) and ascites reduction (VEKB, P < 0.01; VEKC, P < 0.01). These two fractions also balanced the concentrations of Na⁺, K⁺ and Cl^- in urine (VEKB, all P < 0.05; VEKC, all P < 0.05), remarkably decreased urinary pH (VEKB, P < 0.01; VEKC, P < 0.01), and reduced the ascites levels of IL-2, IL-6, TNF-α, IFN-γ and VEGF (VEKB, all P < 0.01; VEKC, all P < 0.01) in the model rats. Moreover, levels of PRA, the serum Ang II, ALD and ADH of model rats were decreased after treated by VEKB and VEKC (VEKB, all P < 0.05; VEKC, all P < 0.05). Meanwhile, the expression of gastrointestinal AQP8 of the model rats was also enhanced after treated by VEKB and VEKC (VEKB, P < 0.01; VEKC, P < 0.01). In the toxicity evaluation, although VEKB and VEKC caused toxic indexes moved to the worse aspects in normal rats, nearly all of these indicators notably improved in the model rats. Additionally, VEKA showed no effect on the indicators, either in the efficacy evaluation or in the toxicity evaluation. And VEKD could significantly improve some indicators (urine volume, concentration of K⁺ in urine, serum MDA, AI and caspase-9) in MAE rats.

CONCLUSIONS

VEKB and VEKC were demonstrated a significant efficacy in treating malignant ascites effusion, which could reduce hepatic and gastrointestinal damage on the model rats but cause the same damage to the normal. These data embody the traditional Chinese medicine application principle: You Gu Wu Yun. And these results will provide reference for the safer and better clinical utilization of kansui.

Hydrogen protects against hyperoxia-induced apoptosis in type II alveolar epithelial cells via activation of PI3K/Akt/Foxo3a signaling pathway

Oxidative stress is regarded as a key regulator in the pathogenesis of prolonged hyperoxia-induced lung injury, which causes injury to alveolar epithelial cells and eventually leads to development of bronchopulmonary dysplasia (BPD). Many studies have shown that hydrogen has a protective effect in a variety of cells. However, the mechanisms by which hydrogen rescues cells from damage due to oxidative stress in BPD remains to be fully elucidated. This study sought to evaluate the effects of hydrogen on hyperoxia-induced lung injury and to investigate the underlying mechanism. Primary type II alveolar epithelial cells (AECIIs) were divided into four groups: control (21% oxygen), hyperoxia (95% oxygen), hyperoxia + hydrogen, and hyperoxia + hydrogen + LY294002 (a PI3K/Akt inhibitor). Proliferation and apoptosis of AECIIs were assessed using MTS assay and flow cytometry (FCM), respectively. Gene and protein expression were detected by quantitative polymerase chain reaction (q-PCR) and western blot analysis. Stimulation with hyperoxia decreased the expression of P-Akt, P- FoxO3a, cyclinD1 and Bcl-2. Hyperoxic conditions increased levels of Bim, Bax, and Foxo3a, which induced proliferation restriction and apoptosis of AECIIs. These effects of hyperoxia were reversed with hydrogen pretreatment. Furthermore, the protective effects of hydrogen were abrogated by PI3K/Akt inhibitor LY294002. The results indicate that hydrogen protects AECIIs from hyperoxia-induced apoptosis by inhibiting apoptosis factors and promoting the expression of anti-apoptosis factors. These effects were associated with activation of the PI3K/Akt/FoxO3a pathway.

Molecular hydrogen: a preventive and therapeutic medical gas for various diseases

Since the 2007 discovery that molecular hydrogen (H2) has selective antioxidant properties, multiple studies have shown that H2 has beneficial effects in diverse animal models and human disease. This review discusses H2 biological effects and potential mechanisms of action in various diseases, including metabolic syndrome, organ injury, and cancer; describes effective H2 delivery approaches; and summarizes recent progress toward H2 applications in human medicine. We also discuss remaining questions in H2 therapy, and conclude with an appeal for a greater role for H2 in the prevention and treatment of human ailments that are currently major global health burdens. This review makes a case for supporting hydrogen medicine in human disease prevention and therapy.

Angiotensin-converting enzyme 2-angiotensin (1-7)-Mas axis prevents pancreatic acinar cell inflammatory response via inhibition of the p38 mitogen-activated protein kinase/nuclear factor-κB pathway

The aim of the present study was to investigate the role of the angiotensin-converting enzyme (ACE)2-angiotensin‑(Ang)-(1-7)-Mas axis in the pathogenesis of pancreatitis and the association between this axis and the p38 mitogen-activated protein kinase (p38 MAPK)/nuclear factor (NF-κB) signaling pathway in pancreatic acinar cells. Mouse pancreatic acinar cancer (MPC-83) cells were stimulated with 10 nM caerulein (CAE) to create an in vitro model of acute pancreatitis, and collected for analysis at 2, 6, 12, 24 and 48 h post stimulation. In addition, cells were pretreated with different concentrations of Ang‑(1‑7), Ang‑(1‑7) antagonist A779, p38 MAPK inhibitor SB203580 or ACE2 inhibitor DX600 for 30 min, and then stimulated with CAE for 24 h. The ACE2, Mas receptor, p38 MAPK, phosphorylated (p)-p38 MAPK and NF-κB expression levels were evaluated using western blotting and immunofluorescence. p38 MAPK, NF-κB, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-8 and IL-10 mRNA expression levels were assessed using reverse transcription-quantitative polymerase chain reaction. The results of the immunofluorescence assay demonstrated that ACE2 and p38 MAPK were present mainly in the cytoplasm, while the Mas receptor was located mainly in the cell membrane. ACE2, p38 MAPK and p-p38 MAPK protein levels were significantly increased (P<0.05) following stimulation with CAE compared with those in the control group and peaked at 24 h. Mas receptor protein levels were significantly upregulated (P<0.05) between 6 and 24 h, peaking at 12 h. Ang‑(1‑7) and SB203580 downregulated p-p38 MAPK and NF-κB expression and the mRNA levels of inflammatory factors IL-6, TNF-α and IL-8, but upregulated the mRNA level of inflammatory factor IL-10 compared with those treated with CAE alone. These results were supported by the opposite outcomes observed for cells treated with A779 or DX600. Therefore, it was concluded that the ACE2-Ang‑(1‑7)-Mas axis significantly inhibits pancreatitis by inhibition of the p38 MAPK/NF-κB signaling pathway.

A preliminary study on fetal lung injury in a rat model of acute pancreatitis in pregnancy

Acute pancreatitis in pregnancy (APIP), which was thought to be rare, is becoming more frequent. In addition, high perinatal mortality among fetuses has been reported. Our research aimed to investigate and assess fetal lung injury in a rat model of APIP and its possible mechanisms. The APIP model was induced by sodium taurocholate in Sprague-Dawley rats during the third trimester. Sham-operated (SO) rats in late gestation were used as controls, and dynamic observation and detection in the SO and acute pancreatitis (AP) groups were performed at 3 time-points. Histological changes in the fetal lungs, as well as the maternal pancreas and placenta were assessed. The levels of serum amylase, lipase, TNF-α and IL-1β were detected in maternal rats, and the expression of surfactant proteins A, B, C and D as well as their mRNA were determined. In this study, fetal lung injury as well as maternal pancreas and placenta injuries occurred in a time-dependent manner. The levels of serum amylase, lipase and TNF-α were markedly increased in maternal rats, and the levels of surfactant proteins A, B, C and D in fetal lungs were significantly decreased in the fetal lungs of the AP group. Ultrastructure injuries and the dysregulated synthesis and secretion of pulmonary surfactant proteins were observed in the AP group. Our research suggests that fetal lung injury is involved in the rat model of APIP and that the dysregulated synthesis and secretion of pulmonary surfactant proteins play a critical role in fetal lung injury during APIP.

Differential susceptibility of mouse strains on pancreatic injury and regeneration in cerulein-induced pancreatitis

Acute pancreatitis (AP), a common disease, causes significant morbidity and mortality in clinical practice. Our objective of this study was to establish an experimental mouse AP model with cerulein treatment and to explore the susceptibility of mouse strains on the severity of pancreatic injury and the subsequent repair and regeneration. C57BL/6 and FVB/N mouse strains were used in this study. AP model was induced by six hourly intraperitoneal (i.p.) injections of cerulein dissolved in saline (100 μg/kg) administered on four consecutive days. Animals were sacrificed on 1, 3 and 7 days after last cerulein treatment, and then pancreas tissues were harvested and subjected to various histological, cellular and molecular analysis. Analyses of pancreatic injury and pancreatic amylase expression indicated that this cerulein-induced AP model was established successfully and that FVB/N mice showed more severe pancreatic injury and poor recovery compared to C57BL/6 strain. Analyses of myeloperoxidase (MPO), IL-1β and NF-κB showed that FVB/N strain exhibited more severe inflammation in the pancreas compared to C57BL/6 mice. Immunofluorescence analysis of activated caspase-3 and TUNEL assay indicated that the pancreas of FVB/N strain had more apoptosis compared to C57BL/6 mice. Analysis of Ki67 indicated FVB/N mice experienced more active proliferation compared to C57BL/6 strain. Collectively, these results demonstrated that there exists differential susceptibility on pancreatic injury and regeneration between FVB/N and C57BL/6 mice in the cerulein-induced AP.

Hydrogen-rich saline prevents bone loss in diabetic rats induced by streptozotocin

PURPOSE

As an antioxidant molecule, hydrogen has been received much more attention and reported to be used as the treatment strategy for various diseases. In this study, we hypothesize that systemic delivery of hydrogen saline water may improve the reservation of bone tissue in the tibias and femurs of osteoporotic rats caused by diabetes mellitus (DM), which is characterized by increased levels of oxidative stress and overproducing reactive oxygen species (ROS).

METHODS

The animals were divided into three groups of 12 animals and lavaged with normal saline (normal control and DM), or hydrogen saline water (DM + HRS). General status, blood glucose level, tibial and femoral mechanical strength, and micro-CT scans of the proximal tibia were recorded and analyzed.

RESULTS

After 12 weeks, the glucose level was significantly decreased in the DM + HRS group compared with that of the DM group. Micro-CT scans showed that bone volume/total volume, connectivity density, trabecular thickness, and trabecular number were significantly increased compared with the DM group. Mechanical results of energy, stiffness and elastic modulus in the DM + HRS group were significantly higher than in the other groups for the tibia and femur.

CONCLUSIONS

The results indicate that the systemic delivery of hydrogen saline water, which is safe and well tolerated, preserves bone volume and decreases fracture risks in streptozotocin-induced diabetic status rats, whose bone structure or inherent material properties of bone tissues are changed.

Hydrogen-rich saline attenuates eosinophil activation in a guinea pig model of allergic rhinitis via reducing oxidative stress

Background

It is well considered that reactive oxygen species (ROS) plays a prominent causative role in the development of allergic rhinitis (AR), and eosinophils cells as important allergic inflammatory cells contribute to elevating oxidative stress. Hydrogen, emerging as a novel antioxidant, has been proven effective in selectively reducing ROS in animals models of oxidative damage. We herein aim to verify protective effects of hydrogen on eosinophils cells in guinea pigs models of AR.

Methods

Thirty two guinea pigs were random divided into four groups, and AR model was established through ovalbumin sensitization. The guinea pigs were injected with hydrogen-rich saline (Normal-HRS and AR-HRS group) or normal saline (control and AR group). The frequencies of sneezing and scratching were recorded. The IgE level, blood eosinophil count and eosinophil cationic protein (ECP) level in serum were measured. The serum malondialdehyde (MDA) and superoxide dismutase (SOD) assays were also measured to evaluate oxidative stress. The expression levels of eotaxin mRNA and protein in the nasal mucosa were also determined by real-time RT-PCR, Western blot and immunofluorescence.

Results

HRS reduced the ROS and MDA levels and increased SOD level in guinea pigs of AR-HRS group accompanied with decreased frequency of sneezing and scratches. Meanwhile, there was a decline of the number of eosinophils cells in blood and of thelevel of ECP in serum in the AR-HRS group. HRS also significantly decreased the expression of eotaxin in nasal mucosa.

Conclusion

HRS may play a protective role in attenuating allergic inflammation, and suppressing the increase and activation of eosinophils in AR possibly through antioxidation effect of hydrogen.

Hydrogen-Rich Saline Promotes the Recovery of Renal Function after Ischemia/Reperfusion Injury in Rats via Anti-apoptosis and Anti-inflammation

Purpose: Hydrogen is a proven novel antioxidant that selectively reduces hydroxyl radicals. In this study, we investigated the effects of hydrogen-rich saline solution on the prevention of renal injury induced by ischemia/reperfusion (I/R) and on renal function recovery.

Methods: A rat model of renal I/R injury was induced by 45 min occlusion of the left renal pedicle, followed by 108 h reperfusion. The right kidney was surgically removed. Then, 0.9% NaCl solution (1 ml/kg) or hydrogen-rich saline solution (HRSS; 1 ml/kg) was injected into the abdominal cavity at 4 h intervals. We assessed the influence of HRSS or control saline solution on the recovery of renal function after I/R injury. Kidney tissues were taken at different time points (24, 36, 48, 72, and 108 h after reperfusion) and frozen (-80°C). Kidney cell apoptosis was evaluated using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive staining. Additionally, the apoptotic factors (Bcl-2, Bax, caspase-3, caspase-9, and caspase-8) and the pro-inflammatory cytokines (IL-6 and TNF-α) were measured in the kidney tissues. Finally, serum blood urea nitrogen (BUN) and creatinine (Cr) levels were measured.

Results: Histological analyses revealed a marked reduction of interstitial congestion, edema and hemorrhage in renal tissue after HRSS treatment compared to saline treatment. After I/R injury, BUN, Cr, Bcl-2, caspase-3, caspase-9, caspase-8, IL-6, and TNF-α were all significantly increased, while Bax expression was decreased. HRSS remarkably reversed these changes. Moreover, BUN and Cr decreased more rapidly in the rats treated with HRSS compared to the rats treated with control saline solution.

Conclusions: HRSS showed a protective effect in the prevention of renal injury and could promote renal function recovery after I/R injury in rats. HRSS might partially exert its role through an anti-apoptotic and anti-inflammatory action in kidney cells.

Beneficial biological effects and the underlying mechanisms of molecular hydrogen - comprehensive review of 321 original articles

Therapeutic effects of molecular hydrogen for a wide range of disease models and human diseases have been investigated since 2007. A total of 321 original articles have been published from 2007 to June 2015. Most studies have been conducted in Japan, China, and the USA. About three-quarters of the articles show the effects in mice and rats. The number of clinical trials is increasing every year. In most diseases, the effect of hydrogen has been reported with hydrogen water or hydrogen gas, which was followed by confirmation of the effect with hydrogen-rich saline. Hydrogen water is mostly given ad libitum. Hydrogen gas of less than 4 % is given by inhalation. The effects have been reported in essentially all organs covering 31 disease categories that can be subdivided into 166 disease models, human diseases, treatment-associated pathologies, and pathophysiological conditions of plants with a predominance of oxidative stress-mediated diseases and inflammatory diseases. Specific extinctions of hydroxyl radical and peroxynitrite were initially presented, but the radical-scavenging effect of hydrogen cannot be held solely accountable for its drastic effects. We and others have shown that the effects can be mediated by modulating activities and expressions of various molecules such as Lyn, ERK, p38, JNK, ASK1, Akt, GTP-Rac1, iNOS, Nox1, NF-κB p65, IκBα, STAT3, NFATc1, c-Fos, and ghrelin. Master regulator(s) that drive these modifications, however, remain to be elucidated and are currently being extensively investigated.