The interaction between oxidative stress and mast cell activation plays a role in acute lung injuries induced by intestinal ischemia–reperfusion

Ischemia-inhibited ferric chelate reductase 1 improves ferroptosis-mediated intestinal ischemia injury via Hippo signaling

The precise mechanism of ferroptosis as a regulatory cell death in intestinal ischemia injury induced by vascular intestinal obstruction (Vio) remains to be elucidated. Here, we evaluated iron levels, glutathione peroxidase 4 (GPX4) and Acyl-CoA synthetase long-chain family member 4 (ACSL4) changes after intestinal ischemia injury to validate ferroptosis. As an enzyme for Fe3+ reduction to Fe2+, Ferric Chelate Reductase 1 (FRRS1) is involved in the electron transport chain and the tricarboxylic acid (TCA) cycle in mitochondria. However, whether it is involved in ferroptosis and its role in intestinal ischemia injury need to be clarified. In the present study, FRRS1 was overexpressed in vivo and in vitro. The results showed that overexpression of FRRS1 prevented ischemia-induced iron levels, reactive oxygen species (ROS) production, lipid peroxidation, inflammatory responses, and cell death. Meanwhile, FRRS1 overexpression promoted GPX4 expression and suppressed ACSL4 levels. Further studies revealed that FRRS1 overexpression inhibited the activity of large tumor suppressor 1 (LATS1) / Yes-associated protein (YAP) / transcriptional co-activator with PDZ-binding motif (TAZ), a key component of Hippo signaling. In conclusion, this study demonstrates that FRRS1 is intimately involved in the inhibition of ferroptosis and thus protection of the intestine from intestinal ischemia injury, its downstream mechanism was related to Hippo signaling. These data provide new sight for the prevention and treatment of intestinal ischemia injury.

Dexmedetomidine against intestinal ischemia/reperfusion injury: A systematic review and meta-analysis of preclinical studies

BACKGROUND

Intestinal ischemia/reperfusion injury (IRI) is a multifactorial, complex pathophysiological process in clinical settings. In recent years, intestinal IRI has received increasing attention due to increased morbidity and mortality. To date, there are no effective treatments. Dexmedetomidine (DEX), a highly selective α2-adrenergic receptor agonist, has been demonstrated to be effective against intestinal IRI. In this systematic review and meta-analysis, we evaluated the efficacy and potential mechanisms of DEX as a treatment for intestinal IRI in animal models.

METHODS

Five databases (PubMed, Embase, Web of Science, Cochrane Library, and Scopus) were searched until March 15, 2023. Using the SYRCLE risk bias tool, we assessed methodological quality. Statistical analysis was conducted using STATA 12 and R 4.2.2. We analyzed the related outcomes (mucosa damage-related indicators; inflammation-relevant markers, oxidative stress markers) relied on the fixed or random-effects models.

RESULTS

There were 15 articles including 18 studies included, and 309 animals were involved in the studies. Compared to the model groups, DEX improved intestinal IRI. DEX decreased Chiu's score and serum diamine oxidase (DAO) level. DEX reduced the level of inflammation-relevant markers (interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α). DEX also improved oxidative stress (decreased malondialdehyde (MDA), increased superoxide dismutase (SOD)).

CONCLUSIONS

DEX's effectiveness in ameliorating intestinal IRI has been demonstrated in animal models. Antioxidation, anti-inflammation, anti-apoptotic, anti-pyroptosis, anti-ferroptosis, enhancing mitophagy, reshaping the gut microbiota, and gut barrier protection are possible mechanisms. However, in light of the heterogeneity and methodological quality of these studies, further well-designed preclinical studies are warranted before clinical implication.

Wheatgrass-and-Aronia-Mixed Extract Suppresses Immunoglobulin E-Mediated Allergic Reactions In Vitro and In Vivo

Mast cells are an important component of immune responses. Immunoglobulin (Ig) E-sensitized mast cells release substances within minutes of allergen exposure, triggering allergic responses. Until now, numerous pharmacological effects of wheatgrass and aronia have been verified, but the effects of wheatgrass and aronia (TAAR)-mixed extract on allergic reactions have not been identified. Therefore, the aim of this study was to demonstrate the anti-allergic effect of TAAR extract on mast cell activation and cutaneous anaphylaxis. In this study, we investigated the anti-allergic effects and related mechanisms of TAAR extract in IgE-activated mast cells in vitro. We also assessed the ameliorating effect of TAAR extract on IgE-mediated passive cutaneous anaphylaxis mice in vivo. The TAAR extract significantly reduced the expression of β-hexosaminidase, histamine, and pro-inflammatory cytokines, which are mediators related to mast cell degranulation, via the regulation of various signaling pathways. The TAAR extract also regulated oxidative-stress-related factors through the Nrf2 signaling pathway. Additionally, treatment of TAAR extract to the passive cutaneous anaphylaxis mouse model improved ear thickness and local ear pigmentation. Taken together, our results suggest that TAAR extract is a potential candidate natural product to treat overall IgE-mediated allergic inflammation and oxidative-stress-related diseases by suppressing mast cell activity.

Protective and therapeutic potential of melatonin against intestinal diseases: updated review of current data based on molecular mechanisms

INTRODUCTION

Intestinal diseases, a leading global cause of mortality and morbidity, carry a substantial socioeconomic burden. Small and large intestines play pivotal roles in gastrointestinal physiology and food digestion. Pathological conditions, such as gut dysbiosis, inflammation, cancer, therapy-related complications, ulcers, and ischemia, necessitate the urgent exploration of safe and effective complementary therapeutic strategies for optimal intestinal health.

AREAS COVERED

This article evaluates the potential therapeutic effects of melatonin, a molecule with a wide range of physiological actions, on intestinal diseases including inflammatory bowel disease, irritable bowel syndrome, colon cancer, gastric/duodenal ulcers and other intestinal disorders.

EXPERT OPINION

Due to anti-inflammatory and antioxidant properties as well as various biological actions, melatonin could be a therapeutic option for improving digestive disorders. However, more researches are needed to fully understand the potential benefits and risks of using melatonin for digestive disorders.

Sevoflurane activates MEF2D-mediated Wnt/β-catenin signaling pathway via microRNA-374b-5p to affect renal ischemia/reperfusion injury

BACKGROUND

The inhaled sevoflurane (Sev) has been demonstrated to protect multiple organs against ischemia/reperfusion injury (IRI). However, the mechanisms of Sev in renal IRI remain largely unknown. This study intends to explore the effect of Sev on renal IRI and the molecular mechanism behind.

METHODS

Following Sev preconditioning, a mouse model with renal IRI was established. The effects of Sev on IRI in mice were assessed by BUN, Scr, MDA and SOD kits, Western blot, HE staining, and TUNEL. Subsequently, we performed microarray analysis on renal tissues from mice with Sev to identify differentially expressed microRNAs (miRNAs). Then, the mice were treated with agomiR-374b-5p combined with Sev to observe the renal histopathology after IRI. The targeting mRNA of miR-374b-5p was verified using bioinformatics analysis and dual-luciferase assay, followed by KEGG enrichment analysis. Rescue experiments were implemented with simultaneous miR-374b-5p and MEF2D overexpression to detect renal histopathology and Wnt/β-catenin pathway activity in the mice.

RESULTS

Sev significantly reduced the levels of BUN and Scr in mouse serum, prevented cell apoptosis, decreased MDA content and increased SOD levels in renal tissues. Moreover, Sev downregulated the miR-374b-5p expression in the renal tissues. Overexpression of miR-374b-5p attenuated the protective effects of Sev on mouse renal tissues. miR-374b-5p targeted MEF2D and blocked the Wnt/β-catenin pathway. Overexpression of MEF2D activated the Wnt/β-catenin pathway and attenuated the supporting effects of miR-374b-5p on renal IRI.

CONCLUSION

Sev promotes MEF2D and activates the Wnt/β-catenin pathway through inhibition of miR-374b-5p expression to affect renal IRI.

Oxidative Stress in Intestinal Ischemia-Reperfusion

Ischemia-reperfusion (I/R) injury is a manifestation of tissue or organ damage that is followed by ischemia and exacerbated by the return of blood flow to a previously damaged tissue or organ. The intestines are one of the most sensitive tissues and organs to I/R injury. Moreover, the adverse consequences of intestinal I/R (II/R) injury are not limited to the intestine itself and can also lead to damage of the distant tissues and organs. The mechanism of II/R is extremely complex and oxidative stress is the key link in the pathogenesis of II/R injury. This study summarizes the roles of oxidative stress and its signaling pathways involved in II/R. The signaling pathways that mitigate II/R injury include the nuclear factor erythroid-related factor 2 (Nrf2)-mediated signaling pathway, Wnt/β-catenin pathway, and phosphatidylinositol kinase 3 (PI3K)/Akt pathway; those that aggravate II/R injury include the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway, Toll-like receptor (TLR) receptor-mediated signaling pathway, protein kinase CβII (PKCβII)/p66shc pathway, and microRNA (miRNA)/p66shc pathway; the effect of miRNA on related pathways and mitochondrial DNA translocation. The aforementioned pathways provide new ideas for further exploring the occurrence and development of II/R and more effective treatments for II/R injury.

Anti-Allergic Effects of Myrciaria dubia (Camu-Camu) Fruit Extract by Inhibiting Histamine H1 and H4 Receptors and Histidine Decarboxylase in RBL-2H3 Cells

Although Myrciaria dubia (camu-camu) has been shown to exert anti-oxidant and anti-inflammatory effects in both in vitro and in vivo studies, its use in allergic responses has not been elucidated. In the present study, the anti-allergic effect of 70% ethanol camu-camu fruit extract was tested on calcium ionophore (A23187)-induced allergies in RBL-2H3 cells. The RBL-2H3 cells were induced with 100 nM A23187 for 6 h, followed by a 1 h camu-camu fruit extract treatment. A23187 sanitization exacerbated mast cell degranulation; however, camu-camu fruit extract decreased the release of histamine and β-hexosaminidase, which are considered as key biomarkers in cell degranulation. Camu-camu fruit extract inhibited cell exocytosis by regulating the calcium/nuclear factor of activated T cell (NFAT) signaling. By downregulating the activation of mitogen-activated protein kinase (MAPK) signaling, camu-camu fruit extract hindered the activation of both histamine H1 and H4 receptors and inhibited histidine decarboxylase (HDC) expression by mediating its transcription factors KLF4/SP1 and GATA2/MITF. In A23187-induced ROS overproduction, camu-camu fruit extract activated nuclear factor erythroid-2-related factor 2 (Nrf2) to protect mast cells against A23187-induced oxidative stress. These findings indicate that camu-camu fruit extract can be developed to act as a mast cell stabilizer and an anti-histamine. This work also “opens the door” to new investigations using natural products to achieve breakthroughs in allergic disorder treatment.

Decline in Mast Cell Density During Diffuse Alveolar Damage in Idiopathic Pulmonary Fibrosis

Mast cells (MCs) are known to be involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF), although their role in acute exacerbations of IPF has not been investigated. The aims of the study were to evaluate the numbers of MCs in fibrotic and non-fibrotic areas of lung tissue specimens of idiopathic pulmonary fibrosis (IPF) patients with or without an acute exacerbation of IPF, and to correlate the MC density with clinical parameters. MCs of IPF patients were quantified from surgical lung biopsy (SLB) specimens (n = 47) and lung tissue specimens taken at autopsy (n = 7). MC density was higher in the fibrotic areas of lung tissue compared with spared alveolar areas or in controls. Female gender, low diffusion capacity for carbon monoxide, diffuse alveolar damage, and smoking were associated with a low MC density. MC densities of fibrotic areas had declined significantly in five subjects in whom both SLB in the stable phase and autopsy after an acute exacerbation of IPF had been performed. There were no correlations of MC densities with survival time or future acute exacerbations. The MC density in fibrotic areas was associated with several clinical parameters. An acute exacerbation of IPF was associated with a significant decline in MC counts. Further investigations will be needed to clarify the role of these cells in IPF and in the pathogenesis of acute exacerbation as this may help to identify some potential targets for medical treatment for this serious disease.

The Complex Interplay between Immunonutrition, Mast Cells, and Histamine Signaling in COVID-19

There is an ongoing need for new therapeutic modalities against SARS-CoV-2 infection. Mast cell histamine has been implicated in the pathophysiology of COVID-19 as a regulator of proinflammatory, fibrotic, and thrombogenic processes. Consequently, mast cell histamine and its receptors represent promising pharmacological targets. At the same time, nutritional modulation of immune system function has been proposed and is being investigated for the prevention of COVID-19 or as an adjunctive strategy combined with conventional therapy. Several studies indicate that several immunonutrients can regulate mast cell activity to reduce the de novo synthesis and/or release of histamine and other mediators that are considered to mediate, at least in part, the complex pathophysiology present in COVID-19. This review summarizes the effects on mast cell histamine of common immunonutrients that have been investigated for use in COVID-19.

Potential of rosmarinic acid to ameliorate toxic effects of diethyl methoxy thio‑phosphoryl thio‑succinate on albino wistar rats' lung, mast cell infiltration inhibitory pathway

Malathion (MA) is a widely used pesticide in agriculture. It can cause toxicity in different organs of the body. Rosmarinic acid (RO) is found in rosemary extract that can be absorbed through gastrointestinal tract mucosa with potent antioxidant, and anti-inflammatory potential. The current study is designed to investigate the potential of RO to protect the lung after MA administration. Forty albino rats were allocated equally to four groups. C-group received corn oil. RO-group received RO orally. MA-group received MA. MA-RO-group received RO in addition to MA. After three weeks the lungs were dissected for histopathological and biochemical investigations. MA-group showed manifestations of severe inflammation with inflammatory cells infiltration in the lung. MA-RO-group showed limited inflammatory cell infiltration. C-group and RO-group appeared with weak anti-survivin immunoreactivity. MA-group showed strong positive immunoreactivity. The reactivity was weakly positive in MA-RO-group. MA-group showed a significant decrease in SP-D gene expression in comparison to the C-group, in addition, MA-RO-group showed a significant increase in SP-D expression. In conclusion, the current study approves that oral administration of MA causes lung injury as it has inflammatory effects, caused by oxidative stress and reports the potential of RO to protect lung tissue against toxic effects of MA through its anti-inflammatory, antioxidant, and anti-apoptotic potential.

MicroRNA-146a overexpression alleviates intestinal ischemia/reperfusion-induced acute lung injury in mice

Previous studies have shown that microRNAs (miRs), such as miR-146a play an important role in the pathogenesis of intestinal ischemia/reperfusion (I/R)-induced injury; however, the role of miR-146a in intestinal I/R-induced acute lung injury has not been elucidated. An intestinal I/R-induced injury mouse model was established in the present study by clamping the superior mesenteric artery and expression levels of miR-146a in intestinal and lung tissue samples were evaluated using reverse transcription-quantitative PCR (RT-qPCR). Intestinal and lung histopathological characteristics in mice with intestinal I/R-induced injury were assessed by hematoxylin and eosin staining, and mRNA and protein expression levels in intestinal and lung tissue samples were evaluated using RT-qPCR and western blotting, respectively. miR-146a expression was significantly downregulated in the intestinal and lung tissue samples of mice with intestinal I/R-induced injury. Intestinal I/R injury-induced histopathological changes in the lung and intestines, and pulmonary edema in mice transduced with an adenoviral miR-146a-overexpression vector (the miR-146a overexpression group) were alleviated. mRNA expression levels of TNF-α, IL-1β, IFN-γ and TGF-β1, and protein expression levels of TNF receptor-associated factor 6, phosphorylated-p65 NF-κB, cleaved caspase-3 and cleaved caspase-9 in lung and intestinal tissue samples were downregulated in I/R-miR-146a-overexpressing mice, compared with those from the I/R-negative control group. Thus, the present study identified that pre-treatment with the miR-146a overexpression vector alleviated intestinal I/R-induced acute lung injury in mice.

Bidirectional communication between mast cells and the gut-brain axis in neurodegenerative diseases: Avenues for therapeutic intervention

Although the global incidence of neurodegenerative diseases has been steadily increasing, especially in adults, there are no effective therapeutic interventions. Neurodegeneration is a heterogeneous group of disorders that is characterized by the activation of immune cells in the central nervous system (CNS) (e.g., mast cells and microglia) and subsequent neuroinflammation. Mast cells are found in the brain and the gastrointestinal tract and play a role in "tuning" neuroimmune responses. The complex bidirectional communication between mast cells and gut microbiota coordinates various dynamic neuro-cellular responses, which propagates neuronal impulses from the gastrointestinal tract into the CNS. Numerous inflammatory mediators from degranulated mast cells alter intestinal gut permeability and disrupt blood-brain barrier, which results in the promotion of neuroinflammatory processes leading to neurological disorders, thereby offsetting the balance in immune-surveillance. Emerging evidence supports the hypothesis that gut-microbiota exert a pivotal role in inflammatory signaling through the activation of immune and inflammatory cells. Communication between inflammatory cytokines and neurocircuits via the gut-brain axis (GBA) affects behavioral responses, activates mast cells and microglia that causes neuroinflammation, which is associated with neurological diseases. In this comprehensive review, we focus on what is currently known about mast cells and the gut-brain axis relationship, and how this relationship is connected to neurodegenerative diseases. We hope that further elucidating the bidirectional communication between mast cells and the GBA will not only stimulate future research on neurodegenerative diseases but will also identify new opportunities for therapeutic interventions.

Intravoxel Incoherent Motion and Dynamic Contrast-Enhanced Magnetic Resonance Imaging to Early Detect Tissue Injury and Microcirculation Alteration in Hepatic Injury Induced by Intestinal Ischemia-Reperfusion in a Rat Model

Background

Intravoxel incoherent motion (IVIM) can provide quantitative information about water diffusion and perfusion that can be used to evaluate hepatic injury, but it has not been studied in hepatic injury induced by intestinal ischemia–reperfusion (IIR). Dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) can provide perfusion data, but it is unclear whether it can provide useful information for assessing hepatic injury induced by IIR.

Purpose

To examine whether IVIM and DCE‐MRI can detect early IIR‐induced hepatic changes, and to evaluate the relationship between IVIM and DCE‐derived parameters and biochemical indicators and histological scores.

Study Type

Prospective pre‐clinical study.

Population

Forty‐two male Sprague–Dawley rats.

Field Strength/Sequence

IVIM‐diffusion‐weighted imaging (DWI) using diffusion‐weighted echo‐planar imaging sequence and DCE‐MRI using fast spoiled gradient recalled‐based sequence at 3.0 T.

Assessment

All rats were randomly divided into the control group (Sham), the simple ischemia group, the ischemia–reperfusion (IR) group (IR1h, IR2h, IR3h, and IR4h) in a model of secondary hepatic injury caused by IIR, and IIR was induced by clamping the superior mesenteric artery for 60 minutes and then removing the vascular clamp. Advanced Workstation (AW) 4.6 was used to calculate the imaging parameters (apparent diffusion coefficient [ADC], true diffusion coefficient [D], perfusion‐related diffusion [D^*] and volume fraction [f]) of IVIM. OmniKinetics (OK) software was used to calculate the DCE imaging parameters (K^trans, K_ep, and V_e). Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed with an automatic biochemical analyzer. Superoxide dismutase (SOD) activity was assessed using the nitro‐blue tetrazolium method. Malondialdehyde (MDA) was determined by thiobarbituric acid colorimetry. Histopathology was performed with hematoxylin and eosin staining.

Statistical Tests

One‐way analysis of variance (ANOVA) and Bonferroni post‐hoc tests were used to analyze the imaging parameters and biochemical indicators among the different groups. Pearson correlation analysis was applied to determine the correlation between imaging parameters and biochemical indicators or histological score.

Results

ALT and MDA reached peak levels at IR4h, while SOD reached the minimum level at IR4h (all P < 0.05). ADC, D, D^*, and f gradually decreased as reperfusion continued, and K^trans and V_e gradually increased (all P < 0.05). The degrees of change for f and V_e were greater than those of other imaging parameters at IR1h (all P < 0.05). All groups showed good correlation between imaging parameters and SOD and MDA (r[ADC] = 0.615, −0.666, r[D] = 0.493, −0.612, r[D^*] = 0.607, −0.647, r[f] = 0.637, −0.682, r[K^trans] = −0.522, 0.500, r[V_e] = −0.590, 0.665, respectively; all P < 0.05). However, the IR groups showed poor or no correlation between the imaging parameters and SOD and MDA (P [K^trans and MDA] = 0.050, P [D and SOD] = 0.125, P [the remaining imaging parameters] < 0.05). All groups showed a positive correlation between histological score and K^trans and V_e (r = 0.775, 0.874, all P < 0.05), and a negative correlation between histological score and ADC, D, f, and D^* (r = −0.739, −0.821, −0.868, −0.841, respectively; all P < 0.05). For the IR groups, there was a positive correlation between histological score and K^trans and V_e (r = 0.747, 0.802, all P < 0.05), and a negative correlation between histological score and ADC, D, f, and D^* (r = −0.567, −0.712, −0.715, −0.779, respectively; all P < 0.05).

Data Conclusion

The combined application of IVIM and DCE‐MRI has the potential to be used as an imaging tool for monitoring IIR‐induced hepatic histopathology.

Level of Evidence

1

Technical Efficacy Stage

2

Concept of 'Ihtiraq' in Unani Medicine - A correlation with oxidative stress, and future prospects

ETHNOPHARMACOLOGICAL RELEVANCE

In recent years, oxidative stress (OS) and the generation of ROS have been recognized as a fundamental pathology contributing, at least partially, to a number of important diseases. However, the therapeutic application has been simplistically limited to using antioxidants with little correction of diseases, and many biomarkers of OS, although confirming and quantifying the magnitude of this pathology, are not suggestive of the underlying causes behind generation of a large amount of free radicals. Unfortunately, research has not noted the multi-implication parallel phenomenon of Ihtiraq (Combustion) in Unani Medicine, which possesses much richer etiopathological sub-typing and much more variegated selective and specific treatments (and prophylactics) corresponding to each sub-type of Ihtiraq; the identification of each sub-type's molecular counterparts can be used to develop not only sub-types of OS pathologies and corresponding selective treatments/prophylactics but also non-biomolecular factors. Eminent Unani physicians described a deteriorative phenomenon, which they termed as 'Ihtiraq' which stands for extreme metabolism or 'combustion' and is recognized as a fundamental pathology, contributing as a major factor to the development of chronic diseases. Further, Unani Medicine also possesses a pathophysiological phenomenon called 'Hararat Ghariba' (Unnatural Heat) whose diverse associations with Ihtiraq may be correlatable as upstream, parallel, or downstream associations of OS and consequent pathologies.

AIM OF THE STUDY

The aim of the study is to: 1. Explore the correlation of the phenomenon and etiopathology of Ihtiraq and OS and the treatment and prevention of the pathologies arising from them. 2. Extrapolate Ihtiraq, its types, causes, prevention, and treatment to OS, hitherto existing as a fundamental and monolithic pathology of increased ROS, to hypothesize its molecular-level sub-typing, as well as to propose selective interventions in these molecular sub-types of OS in place of the existing use of only basic antioxidants such as Vitamin C.

MATERIAL AND METHODS

This review is presented with a noteworthy insight into Unani concepts and a thorough study of classical Unani literature by Ibn Sina (10th century), Zakaria Razi (9th century), Ibn Rushd (12th century), Ibn al-Nafees (13th century), Majusi (10th century), and Jurjani (11th century), and comparative detailed study of modern concepts of OS from literature databases, as well as Google, recent researches, and review articles.

RESULT

The study showed very close correspondences between the phenomenon, etiopathology, and treatment and prevention of Ihtiraq in Unani Medicine and OS in contemporary biomolecular medicine. It also revealed sub-types of Ihtiraq and corresponding selective Unani treatments and prophylactics including drugs and non-drug factors.

CONCLUSION

After a comprehensive study and analysis of the most recent researches and classical theories, it can be stated that OS can be seen as a molecular level expression of Ihtiraq. Further, various components of Ihtiraq may be used to hypothesize molecular sub-types of OS and propose corresponding specific interventions.

Computationally designed p-coumaric acid analogs: searching for neuroprotective antioxidants

Newly designed p-coumaric acid derivatives are promising candidates as multifunctional antioxidants with neuroprotective effects.

Therapeutic hypothermia reduces inflammation and oxidative stress in the liver after asphyxial cardiac arrest in rats

BACKGROUND

Few studies have evaluated the effects of hypothermia on cardiac arrest (CA)-induced liver damage. This study aimed to investigate the effects of hypothermic therapy on the liver in a rat model of asphyxial cardiac arrest (ACA).

METHODS

Rats were subjected to 5-minute ACA followed by return of spontaneous circulation (RoSC). Body temperature was controlled at 33°C±0.5°C or 37°C±0.5°C for 4 hours after RoSC in the hypothermia group and normothermia group, respectively. Liver tissues in each group were collected at 6 hours, 12 hours, 1 day, and 2 days after RoSC. To examine hepatic inflammation, mast cells were stained with toluidine blue. Superoxide anion radical production was evaluated using dihydroethidium fluorescence straining and expression of endogenous antioxidants (superoxide dismutase 1 [SOD1] and SOD2) was examined using immunohistochemistry.

RESULTS

There were significantly more mast cells in the livers of the normothermia group with ACA than in the hypothermia group with ACA. Gradual increase in superoxide anion radical production was found with time in the normothermia group with ACA, but production was significantly suppressed in the hypothermia group with ACA relative to the normothermia group with ACA. SOD1 and SOD2 levels were higher in the hypothermia group with ACA than in the normothermia group with ACA.

CONCLUSIONS

Experimental hypothermic treatment after ACA significantly inhibited inflammation and superoxide anion radical production in the rat liver, indicating that this treatment enhanced or maintained expression of antioxidants. Our findings suggest that hypothermic therapy after CA can reduce mast cell-mediated inflammation through regulation of oxidative stress and the expression of antioxidants in the liver.

Effect of nicotinamide supplementation in in vitro fertilization medium on bovine embryo development

Increased oxidative stress is one of the main causes of poorly developed embryos in assisted reproductive technologies. Nicotinamide (NAM) has been shown to suppress reactive oxygen species (ROS) production through its potent antioxidative and anti-senescent effects. In the present study, we explored the effects of short-term NAM-treatment (3 and 5 h) during in vitro fertilization (IVF) on the development of bovine embryos. Treatment with 10 mM NAM for 3 h significantly increased the blastocyst formation but extending the treatment to 5 h did not enhance the benefits any further. Immunofluorescence analysis demonstrated that treatment with 10 mM NAM for 3 h decreased the expression of intracellular ROS, 8-oxo-7,8-dihydroguanine, caspase-3, and increased the expression of Sirt1, and incorporation of bromodeoxyuridine in one-cell stage embryos. Similarly, the level of H3K56ac significantly increased in the NAM-treated (3 and 5 h) one-cell stage embryos. Contrastingly, the treatment with 10 mM NAM for 5 h increased the caspase-9 level in blastocysts. Collectively, these findings suggest that NAM possesses antioxidant activity and supplementation of IVF medium with 10 mM NAM for 3 h improves the in vitro developmental competence of bovine embryos.

MiR-23a-5p exacerbates intestinal ischemia-reperfusion injury by promoting oxidative stress via targeting PPAR alpha

MiR-23a-5p is involved in the occurrence and development of some serious diseases, but its effects on intestinal ischemia-reperfusion (II/R) injury is unclear. In this research, the hypoxia/reoxygenation (H/R) model on IEC-6 cells and II/R model in mice were used. The data showed that the ROS level in model group was significantly increased compared with control group. The level of intestinal MPO was increased and serum SOD was decreased in mice compared with sham group. Moreover, the expression levels of miR-23a-5p in model groups were obviously increased in vitro and in vivo, while the expression levels of PPARα, FOXO3α, PGC-1α, Nrf2, CAT, NQO1, HO-1 and SOD2 were significantly decreased. The double luciferase reporter gene assay showed that there was binding site between miR-23a-5p and PPARα. When miR-23a-5p was inhibited or PPARα gene was overexpressed, H/R-caused cell damage was alleviated and ROS level was decreased compared with NC group. PPARα expression level was increased, accompanied by the increased levels of FOXO3α, PGC-1α, Nrf2, CAT, NQO1, HO-1 and SOD2. After enhancing miR-23a-5p expression or silencing PPARα gene, H/R-caused cell damage was further aggravated compared with NC group, and ROS level was increased associated with the decreased levels of FOXO3α, PGC-1α, Nrf2, CAT, NQO1, HO-1 and SOD2. Our study demonstrated that miR-23a-5p exacerbated II/R injury by promoting oxidative stress via targeting PPARα, which should be considered as one new drug target to treat II/R injury.

Aggravated intestinal ischemia‑reperfusion injury is associated with activated mitochondrial autophagy in a mouse model of diabetes

Numerous studies have reported that diabetes is associated with an increased susceptibility to cardiac ischemia- reperfusion injury; however, the mechanism underlying the role of diabetes during intestinal ischemia-reperfusion (IIR) has yet to be elucidated. The present study evaluated the intestinal pathological alterations and possible underlying mechanisms in a mouse model of type 1 diabetes mellitus with IIR. The effects of diabetes were investigated by assessing the histopathology, oxidative stress, inflammatory cytokine levels in intestine tissues and blood plasma, and protein expression levels of phosphatase and tensin homolog-induced putative kinase (PINK1), Parkin and the ratio of light chain 3B (LC3B) II/I. The results demonstrated that diabetes increased the Chiu's intestinal injury score, concentration of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, and levels of oxidative stress. Furthermore, the alterations were more pronounced in the diabetes with IIR group. The expression levels of PINK1 and Parkin, as well as the ratio of LC3BII/I, were significantly upregulated in the IIR group compared with the Sham group. Diabetes activated PINK1 and Parkin, and increased the expression of LC3BII. Furthermore, transmission electron microscopy revealed that mitochondrial destruction and the number of autophagosomes was increased in the diabetic groups compared with the non-diabetic groups. Collectively, the results of the present study suggest that diabetes increased intestinal vulnerability to IIR by enhancing inflammation and oxidative stress. Furthermore, IIR was associated with overactivation of mitochondrial autophagy; therefore, the increased vulnerability to IIR-induced intestine damage due to diabetes may be associated with PINK1/Parkin-regulated mitochondrial autophagy.

Quercetin postconditioning attenuates gastrocnemius muscle ischemia/reperfusion injury in rats

Quercetin, an antioxidant derived from plants, can play a beneficial role in the protection of various tissues against ischemia-reperfusion injuries (IRI). The purpose of the present research was to investigate the protective effects of quercetin on gastrocnemius muscle ischemia-reperfusion. A total of 80 adult male Wistar rats (weights: 250-300 g) were divided into ten groups (n = 8 per group). We used silk 6.0 surgical thread to create a knit to occlude the femoral artery and vein for 3 hr. The treated groups, which comprised half of each experimental group, received intraperitoneal injections of 150 mg/kg quercetin after the ischemia. Blood flow was subsequently reestablished in the reperfusion phase. The rats were kept in reperfusion for 3, 7, 14, or 28 days after which they were killed with high doses of anesthetic drugs, and the gastrocnemius muscles were removed and fixed. Tissue processing, hematoxylin and eosin and toluidine blue staining, and immunohistochemistry were used to assess tumor necrosis factor-α (TNF-α) and nuclear factor κB (NF-κB) levels. A comparison between treated and untreated ischemic sites showed that on the third day of reperfusion, the severity of edema and NF-κB level decreased significantly; on the 7th day of reperfusion, the severity of edema and the levels of TNF-α and NF-κB decreased significantly; and on the 14th day of reperfusion, all of the parameters showed significant decreases. On the 28th day of reperfusion, there were significantly decreased levels of TNF-α and NF-κB, and decreased mast cell infiltration when compared with the untreated groups. According to the results, administration of quercetin after ischemia could significantly prevent gastrocnemius muscle IRI.

Pretreatment with dexmedetomidine alleviates lung injury in a rat model of intestinal ischemia reperfusion

The aim of the present study was to investigate the antioxidant mechanisms of dexmedetomidine against lung injury during intestinal ischemia reperfusion (IIR) in rats. The model of IIR-induced acute lung injury was established by occluding the superior mesenteric artery (SMA) for 1 h and reperfusing for 2 h using Sprague-Dawley rats. Pathological examination was used to assess the extent of the lung injury. Oxidative stress was evaluated by measuring malondialdehyde, myeloperoxidase and superoxide dismutase in the lung and plasma. The proinflammatory cytokines tumor necrosis factor-α and interleukin-6 were determined via an enzyme-linked immunosorbent assay. The mRNA and protein expression of nuclear factor-erythroid 2 related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) were determined using a reverse transcription-quantitative polymerase chain reaction and western blotting. Pretreatment with dexmedetomidine significantly inhibited the oxidative stress response and proinflammatory factor release caused by IIR compared with the normal saline group (MDA and SOD in lung and plasma, P<0.05; MPO, IL-1β and TNF-α in lung and plasma, P<0.05). Dexmedetomidine improved pulmonary pathological changes in IIR rats compared with the normal saline group. Investigations into the molecular mechanism revealed that dexmedetomidine increased the expression levels of Nrf2 and HO-1 via activating α2 adrenergic receptors compared with the normal saline group. The antagonism of α2 adrenergic receptors may reverse the protective effect of dexmedetomidine on lung injury during IIR, including decreasing the expression levels of Nrf2 and HO-1, elevating the oxidative stress response and increasing the proinflammatory factor release. In conclusion, pretreatment with dexmedetomidine demonstrated protective effects against lung injury during IIR via α2 adrenergic receptors. The Nrf2/HO-1 signaling pathway may serve a function in the protective effect of dexmedetomidine.

Detailed Investigation of the Outstanding Peroxyl Radical Scavenging Activity of Two Novel Amino-Pyridinol-Based Compounds

The ability of two novel amino-pyridinol based compounds (NPyr6 and NPyr7) as peroxyl radical scavengers was investigated in silico. The gathered data indicate that they are exceptionally efficient in that role. However, solvent polarity influences their relative efficiency for that purpose. NPyr6 was identified as the best peroxyl radical scavenger in lipid solution, while NPyr7 takes that place in aqueous solution. Both compounds present two acid-base equilibria, which influence their reactivity in aqueous solution. The associated pKa values were estimated. Several reaction mechanisms were explored. Hydrogen transfer from the phenolic group was identified as the chemical route with the highest contribution to the antioxidant behavior of the investigated compounds in both, nonpolar medium and aqueous solution (at 2 ≤ pH ≤ 10). At higher pH other reaction pathways become the most relevant ones. In addition, their bioavailability, cell permeability, safety, and manufacturability were evaluated. According to these, particularly toxicity, NPyr7 seems to be a better candidate for use as an oral drug to fight oxidative stress than NPyr6.

Sevoflurane alleviates LPS‑induced acute lung injury via the microRNA‑27a‑3p/TLR4/MyD88/NF‑κB signaling pathway

Acute lung injury (ALI) is a critical syndrome that is associated with a high morbidity and mortality in patients. Sevoflurane has a lung protective effect in ALI as it reportedly has anti‑inflammatory and apoptotic‑regulating activity. However, the mechanism is still not entirely understood. The aim of the present study was to explore the effects of sevoflurane on lipopolysaccharide (LPS)‑induced ALI in mice and the possible mechanisms involved. The results revealed that sevoflurane treatment improved LPS‑induced lung injury, as evidenced by the reduction in mortality, lung permeability, lung wet/dry ratio and lung histopathological changes in mice. Total cell counts and the production of pro‑inflammatory cytokines [tumor necrosis factor‑α, interleukin (IL)‑1β and IL‑6] in bronchoalveolar fluid were also decreased following treatment with sevoflurane. Additionally, LPS‑triggered apoptosis in lung tissues, which was eliminated by sevoflurane. Furthermore, a miRCURY™ LNA array was employed to screen for differentially expressed microRNAs (miRs/miRNAs). Among these miRNAs, 6 were differentially expressed and were involved in the inflammatory response, but only miR‑27a‑3p (miR‑27a) was regulated by sevoflurane. Subsequently, the present study investigated whether sevoflurane exerts its function through the modulation of miR‑27a. The results demonstrated that the overexpression of miR‑27a via an injection with agomiR‑27a produced similar protections as sevoflurane, while the inhibition of miR‑27a suppressed the lung protective effects of sevoflurane in ALI mice. In addition, the present study identified that miR‑27a inhibited Toll‑like receptor 4 (TLR4) by binding to its 3'‑untranslated region. Western blot analysis demonstrated that sevoflurane may ameliorate the inflammatory response by blocking the miR‑27a/TLR4/MyD88/NF‑κB signaling pathway. The present results indicate that sevoflurane may be a viable therapeutic option in the treatment of patients with ALI.

Ginsenoside Rb1 attenuates intestinal ischemia/reperfusion‑induced inflammation and oxidative stress via activation of the PI3K/Akt/Nrf2 signaling pathway

Ginsenoside Rb1 (GRb1), one of the major active saponins isolated from ginseng, has recently been reported to protect various organs against ischemia/reperfusion (IR) injury; however, the mechanisms underlying these protective effects following intestinal IR (IIR) remain unclear. The present study aimed to evaluate the effects of GRb1 on IIR injury and determine the mechanisms involved in these effects. Sprague Dawley rats were subjected to 75 min of superior mesenteric artery occlusion, followed by 3 h of reperfusion. GRb1 (15 mg/kg) was administered intraperitoneally 1 h prior to the induction of IIR, with or without intravenous administration of Wortmannin [WM; a phosphoinositide 3-kinase (PI3K) inhibitor, 0.6 mg/kg]. The degree of intestinal injury and oxidative stress-induced damage was determined by histopathologic evaluation and measurement of the serum activity levels of D-lactate, diamine oxidase and endotoxin, and the levels of malondialdehyde (MDA), superoxide dismutase (SOD) and 8-iso-prostaglandin F_2α (8-iso-PGF_2α). The protein expression levels of p85, phosphorylated (p)-p85, protein kinase B (Akt), p-Akt and nuclear factor erythroid 2-related factor 2 (Nrf2) were determined via western blotting, and the concentrations of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 were measured via ELISA. It was revealed that IIR led to severe intestinal injury (as determined by significant increases in intestinal Chiu scores), which was accompanied with disruptions in the integrity of the intestinal mucosal barrier. IIR also increased the expression levels of TNF-α, IL-1β, IL-6, MDA and 8-iso-PGF_2α in the intestine, and decreased those of SOD. GRb1 reduced intestinal histological injury, and suppressed inflammatory responses and oxidative stress. Additionally, the protective effects of GRb1 were eliminated by WM. These findings indicated that GRb1 may ameliorate IIR injury by activating the PI3K/protein kinase B/Nrf2 pathway.

Mast Cells Induce Blood Brain Barrier Damage in SCD by Causing Endoplasmic Reticulum Stress in the Endothelium

Endothelial dysfunction underlies the pathobiology of cerebrovascular disease. Mast cells are located in close proximity to the vasculature, and vasoactive mediators released upon their activation can promote endothelial activation leading to blood brain barrier (BBB) dysfunction. We examined the mechanism of mast cell-induced endothelial activation via endoplasmic reticulum (ER) stress mediated P-selectin expression in a transgenic mouse model of sickle cell disease (SCD), which shows BBB dysfunction. We used mouse brain endothelial cells (mBECs) and mast cells-derived from skin of control and sickle mice to examine the mechanisms involved. Compared to control mouse mast cell conditioned medium (MCCM), mBECs incubated with sickle mouse MCCM showed increased, structural disorganization and swelling of the ER and Golgi, aggregation of ribosomes, ER stress marker proteins, accumulation of galactose-1-phosphate uridyl transferase, mitochondrial dysfunction, reactive oxygen species (ROS) production, P-selectin expression and mBEC permeability. These effects of sickle-MCCM on mBEC were inhibited by Salubrinal, a reducer of ER stress. Histamine levels in the plasma, skin releasate and in mast cells of sickle mice were higher compared to control mice. Compared to control BBB permeability was increased in sickle mice. Treatment of mice with imatinib, Salubrinal, or P-selectin blocking antibody reduced BBB permeability in sickle mice. Mast cells induce endothelial dysfunction via ER stress-mediated P-selectin expression. Mast cell activation contributes to ER stress mediated endothelial P-selectin expression leading to increased endothelial permeability and impairment of BBB. Targeting mast cells and/or ER stress has the potential to ameliorate endothelial dysfunction in SCD and other pathobiologies.

Melatonin and its metabolites vs oxidative stress: From individual actions to collective protection

Oxidative stress (OS) represents a threat to the chemical integrity of biomolecules including lipids, proteins, and DNA. The associated molecular damage frequently results in serious health issues, which justifies our concern about this phenomenon. In addition to enzymatic defense mechanisms, there are compounds (usually referred to as antioxidants) that offer chemical protection against oxidative events. Among them, melatonin and its metabolites constitute a particularly efficient chemical family. They offer protection against OS as individual chemical entities through a wide variety of mechanisms including electron transfer, hydrogen transfer, radical adduct formation, and metal chelation, and by repairing biological targets. In fact, many of them including melatonin can be classified as multipurpose antioxidants. However, what seems to be unique to the melatonin's family is their collective effects. Because the members of this family are metabolically related, most of them are expected to be present in living organisms wherever melatonin is produced. Therefore, the protection exerted by melatonin against OS may be viewed as a result of the combined antioxidant effects of the parent molecule and its metabolites. Melatonin's family is rather exceptional in this regard, offering versatile and collective antioxidant protection against OS. It certainly seems that melatonin is one of the best nature's defenses against oxidative damage.

Comprehensive Investigation of the Antioxidant and Pro-oxidant Effects of Phenolic Compounds: A Double-Edged Sword in the Context of Oxidative Stress?

Oxidative stress (OS) is a health-threatening process that is involved, at least partially, in the development of several diseases. Although antioxidants can be used as a chemical defense against OS, they might also exhibit pro-oxidant effects, depending on environmental conditions. In this work, such a dual behavior was investigated for phenolic compounds (PhCs) within the framework of the density functional theory and based on kinetic data. Multiple reaction mechanisms were considered in both cases. The presence of redox metals, the pH, and the possibility that PhCs might be transformed into benzoquinones were identified as key aspects in the antioxidant versus pro-oxidant effects of these compounds. The main virtues of PhCs as antioxidants are their radical trapping activity, their regeneration under physiological conditions, and their behavior as OH-inactivating ligands. The main risks of PhCs as pro-oxidants are predicted to be the role of phenolate ions in the reduction of metal ions, which can promote Fenton-like reactions, and the formation of benzoquinones that might cause protein arylation at cysteine sites. Although the benefits seem to overcome the hazards, to properly design chemical strategies against OS using PhCs, it is highly recommended to carefully explore their duality in this context.

Linarin prevents LPS‑induced acute lung injury by suppressing oxidative stress and inflammation via inhibition of TXNIP/NLRP3 and NF‑κB pathways

Acute lung injury (ALI) is an important cause of morbidity and mortality for critically ill patients, and linarin (LR) may be a potential treatment for ALI as it reportedly has antioxidant, anti-inflammatory and apoptotic-regulating activity. In the present study, the authors report that saline and LR (12.5, 25 and 50 mg/kg) were applied to male C57BL/6 mice via gavage. Then, mice were intratracheally injected with either saline or lipopolysaccharide (LPS). LR-pretreatment attenuated LPS-induced ALI and platelet activation and reduced CD41 expression levels and neutrophil platelet aggregates. Additionally, LPS-triggered pulmonary myeloperoxidase activity and neutrophil infiltration in lung tissues, and this was eliminated by LR dose-dependently. Furthermore, LPS-induced oxidative stress and pro-inflammatory cytokine release were downregulated by LR by inhibiting thioredoxin-interacting protein and nuclear factor-κB signaling pathways, including their downstream and upstream signals, such as xanthine oxidase, NLR family WHAT, pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC), caspase-1, IκB kinase-α (IKK-α) and IκBα. Moreover, in LPS-induced mice, the mitogen-activated protein kinase pathway was inactivated by LR. In vitro, LR reduced LPS-induced inflammation and oxidative stress, which was linked to reduction of ROS. In conclusion, LR pretreatment may be protective against LPS-induced ALI.

Differentiation and Functionality of Bone Marrow-Derived Mast Cells Depend on Varying Physiologic Oxygen Conditions

Mast cells (MCs) are long-living multifunctional innate immune cells that originate from hematopoietic precursors and specifically differentiate in the destination tissue, e.g., skin, respiratory mucosa, intestine, where they mediate immune cell recruitment and antimicrobial defense. In vivo these tissues have characteristic physiological oxygen levels that are considerably lower than the atmospheric oxygen conditions (159 mmHg, 21% O₂; 5% CO₂) traditionally used to differentiate MCs and to study their functionality in vitro. Only little is known about the impact of physiological oxygen conditions on the differentiation process of MCs. This study aimed to characterize the differentiation of immature murine bone marrow-derived MCs under physioxia in vitro (7% O₂; 53 mmHg; 5% CO₂). Bone marrow-derived suspension cells were differentiated in the presence of interleukin-3 with continuous, non-invasive determination of the oxygen level using a Fibox4-PSt3 measurement system without technique-caused oxygen consumption. Trypan blue staining confirmed cellular viability during the specified period. Interestingly, MCs cultivated at 7% O₂ showed a significantly delayed differentiation rate defined by CD117-positive cells, analyzed by flow cytometry, and reached >95% CD117 positive population at day 32 after isolation. Importantly, MCs differentiated under physioxia displayed a decreased transcript expression level of hif-1α and selected target genes vegf, il-6, and tnf-α, but an increase of foxo3 and vhl expression compared to MCs cultivated under normoxia. Moreover, the production of reactive oxygen species as well as the amount of intracellular stored histamine was significantly lower in MCs differentiated under low oxygen levels, which might have consequences for their function such as immunomodulation of other immune cells. These results show for the first time that physioxia substantially affect maturation and the properties of MCs and highlight the need to study their function under physiologically relevant oxygen conditions.

Interleukin‑6 RNA knockdown ameliorates acute lung injury induced by intestinal ischemia reperfusion in rats by upregulating interleukin‑10 expression

Acute lung injury (ALI) is a common complication following intestinal ischemia/reperfusion (II/R) injury and contributes to the associated high mortality rate. However, the underlying mechanism is poorly understood and treatments are limited. RNA interference (RNAi) has been demonstrated to provide a promising disease treatment strategy both in vitro and in vivo. Therefore, the present study aimed to test whether blocking the proinflammatory cytokine IL‑6 by RNAi may protect the lungs from remote organ injury following II/R, and to investigate the potential underlying mechanisms. A total of 176 adult healthy male Sprague‑Dawley rats were randomly divided into sham, II/R, negative‑control and IL‑6‑short hairpin (sh)RNA groups. The rats underwent II/R injury with occlusion of the superior mesenteric artery and coeliac artery to induce ischemia for 40 min, and were subsequently reperfused for 0‑48 h. The negative‑control group received a control lentiviral vector containing scrambled or non‑specific sequences, and the IL‑6‑shRNA groups were administered with a vector containing an IL‑6 shRNA sequence to affect RNAi‑mediated knockdown of IL‑6. ALI severity was determined by lung edema (lung wet/dry ratio) and histological analysis (lung injury scores). IL‑6 localization, and mRNA and protein expression levels, were detected by immunofluorescence, reverse transcription‑quantitative polymerase chain reaction and western blot analysis, respectively. IL‑10 expression induced by IL‑6 knockdown in lung tissues was additionally detected. IL‑6 RNAi was revealed to significantly reduce the expression of IL‑6, which was associated with upregulated IL‑10 expression in lung tissues. Consequently, the severities of ALI and edema induced by II/R were substantially improved. In conclusion, the present study demonstrated that IL‑6 RNAi may protect the lung from ALI induced by II/R, and that this protective role may be associated with upregulation of IL‑10. These findings may contribute to the development of an IL‑6‑RNAi‑based therapeutic strategy for the treatment of II/R‑induced ALI.

Erythropoietin Pretreatment Attenuates Seawater Aspiration-Induced Acute Lung Injury in Rats

Seawater drowning-induced acute lung injury (ALI) is a serious clinical condition characterized by increased alveolar-capillary permeability, excessive inflammatory responses, and refractory hypoxemia. However, current therapeutic options are largely supportive; thus, it is of great interest to search for alternative agents to treat seawater aspiration-induced ALI. Erythropoietin (EPO) is a multifunctional agent with antiinflammatory, antioxidative, and antiapoptotic properties. However, the effects of EPO on seawater aspiration-induced ALI remain unclear. In the present study, male rats were randomly assigned to the naive group, normal saline group, seawater group, or seawater + EPO group. EPO was administered intraperitoneally at 48 and 24 h before seawater aspiration. Arterial blood gas analysis was performed with a gas analyzer at baseline, 30 min, 1 h, 4 h, and 24 h after seawater aspiration, respectively. Histological scores, computed tomography scan, nuclear factor kappa B p65, inducible nitric oxide synthase, caspase-3, tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6, IL-10, wet-to-dry weight ratio, myeloperoxidase activity, malondialdehyde, and superoxide dismutase in the lung were determined 30 min after seawater aspiration. Our results showed that EPO pretreatment alleviated seawater aspiration-induced ALI, as indicated by increased arterial partial oxygen tension and decreased lung histological scores. Furthermore, EPO pretreatment attenuated seawater aspiration-induced increase in the expressions of pulmonary nuclear factor kappa B p65, inducible nitric oxide synthase, caspase-3, tumor necrosis factor-alpha, IL-1β, myeloperoxidase activity, and malondialdehyde when compared with the seawater group. Collectively, our study suggested that EPO pretreatment attenuates seawater aspiration-induced ALI by down-regulation of pulmonary pro-inflammatory cytokines, oxidative stress, and apoptosis.

Curcumin use in pulmonary diseases: State of the art and future perspectives

Curcumin (diferuloylmethane) is a yellow pigment present in the spice turmeric (Curcuma longa). It has been used for centuries in Ayurveda (Indian traditional medicine) for the treatment of several diseases. Over the last several decades, the therapeutic properties of curcumin have slowly been elucidated. It has been shown that curcumin has pleiotropic effects, regulating transcription factors (e.g., NF-kB), cytokines (e.g., IL6, TNF-alpha), adhesion molecules (e.g., ICAM-1), and enzymes (e.g., MMPs) that play a major role in inflammation and cancerogenesis. These effects may be relevant for several pulmonary diseases that are characterized by abnormal inflammatory responses, such as asthma or chronic obstructive pulmonary disease, acute respiratory distress syndrome, pulmonary fibrosis, and acute lung injury. Furthermore, some preliminary evidence suggests that curcumin may have a role in the treatment of lung cancer. The evidence for the use of curcumin in pulmonary disease is still sparse and has mostly been obtained using either in vitro or animal models. The most important issue with the use of curcumin in humans is its poor bioavailability, which makes it necessary to use adjuvants or curcumin nanoparticles or liposomes. The aim of this review is to summarize the available evidence on curcumin's effectiveness in pulmonary diseases, including lung cancer, and to provide our perspective on future research with curcumin so as to improve its pharmacological effects, as well as provide additional evidence of curcumin's efficacy in the treatment of pulmonary diseases.

Sevoflurane protects against hepatic ischemia/reperfusion injury by modulating microRNA-200c regulation in mice

This present study was aimed to investigate the molecular mechanisms involved in sevoflurane protection of hepatic ischemia-reperfusion (I/R) injury. Firstly, we investigated the protective effects of sevoflurane against hepatic I/R injury. Biochemical analysis results showed that sevoflurane preconditioning significantly protected against hepatic I/R injury by reducing liver enzymes and improving antioxidant defense markers. We also found that sevoflurane attenuates I/R-induced hepatic cell death, by TUNEL staining, DNA fragmentation ELISA and PARP activity determination. Next, In order to find the molecular mechanism of sevoflurane preconditioning in hepatic I/R injury, we poured our attention to microRNAs regulation. We focused on miR-200c, one of microRNAs which screened from the gene expression omnibus (GEO). Furthermore, a hydrogen peroxide (H₂O₂)-induced oxidative stress apoptosis model was also established to mimic hepatic I/R injury, the effects of MiR-200c was investigated. We observed that MiR-200c inhibition decreased the H₂O₂-induced apoptosis of hepatic AML-12 cells. And also, ZEB1 is found as a target gene of miR-200c and is involved in H₂O₂-induced apoptosis. On the other hand, the in vivo model was established to examine whether sevoflurane protect against hepatic IR injury by downregulating MiR-200c. Together with the biochemical tests and apoptosis detection, results showed that over-expression of miR-200c significantly inhibited the protect effect of sevoflurane in Hepatic IR injury. Summarizing, sevoflurane preconditioning seems to ameliorate hepatic I/R injury in mice, mediated by mechanisms that include microRNA 200c down regulation. However, further more studies need to be carried out to verify this point.

Mast cells and their activation in lung disease

Mast cells and their activation contribute to lung health via innate and adaptive immune responses to respiratory pathogens. They are also involved in the normal response to tissue injury. However, mast cells are involved in disease processes characterized by inflammation and remodeling of tissue structure. In these diseases mast cells are often inappropriately and chronically activated. There is evidence for activation of mast cells contributing to the pathophysiology of asthma, pulmonary fibrosis, and pulmonary hypertension. They may also play a role in chronic obstructive pulmonary disease, acute respiratory distress syndrome, and lung cancer. The diverse mechanisms through which mast cells sense and interact with the external and internal microenvironment account for their role in these diseases. Newly discovered mechanisms of redistribution and interaction between mast cells, airway structural cells, and other inflammatory cells may offer novel therapeutic targets in these disease processes.

Coumarin-Chalcone Hybrids as Peroxyl Radical Scavengers: Kinetics and Mechanisms

The primary antioxidant activity of coumarin-chalcone hybrids has been investigated using the density functional and the conventional transition state theories. Their peroxyl radical scavenging ability was studied in solvents of different polarity and taking into account different reaction mechanisms. It was found that the activity of the hybrids increases with the polarity of the environment and the number of phenolic sites. In addition, their peroxyl radical scavenging activity is larger than those of the corresponding nonhybrid coumarin and chalcone molecules. This finding is in line with previous experimental evidence. All the investigated molecules were found to react faster than Trolox with (•)OOH, regardless of the polarity of the environment. The role of deprotonation on the overall activity of the studied compounds was assessed. The rate constants and branching ratios for the reactions of all the studied compounds with (•)OOH are reported for the first time.

Protective effects of fenofibrate against acute lung injury induced by intestinal ischemia/reperfusion in mice

This experiment was conducted to evaluate whether pretreatment with fenofibrate could mitigate acute lung injury (ALI) in a mice model of intestinal ischemia/reperfusion (I/R). Male C57BL/6 mice were randomly assigned into three groups (n = 6): sham, intestinal I/R + vehicle, and intestinal I/R + fenofibrate. Intestinal I/R was achieved by clamping the superior mesenteric artery. Fenofibrate (100 mg/kg) or equal volume of vehicle was injected intraperitoneally 60 minutes before the ischemia. At the end of experiment, measurement of pathohistological score, inflammatory mediators and other markers were performed. In addition, a 24-hour survival experiment was conducted in intestinal I/R mice treated with fenofibrate or vehicle. The chief results were as anticipated. Pathohistological evaluation indicated that fenofibrate ameliorated the local intestine damage and distant lung injury. Pretreatment with fenofibrate significantly decreased inflammatory factors in both the intestine and the lung. Consistently, renal creatine levels and hepatic ALT levels were significantly decreased in the fenofibrate group. Moreover, serum systemic inflammatory response indicators were significantly alleviated in the fenofibrate group. In addition, fenofibrate administration significantly improved the survival rate. Collectively, our data indicated that pretreatment with fenofibrate prior to ischemia attenuated intestinal I/R injury and ALI.

Ukrain (NSC 631570) ameliorates intestinal ischemia-reperfusion-induced acute lung injury by reducing oxidative stress

Intestinal ischemia-reperfusion (I/R) causes severe destruction in remote organs. Lung damage is a frequently seen complication after intestinal I/R. Ukrain (NSC 631570) is a synthetic thiophosphate derivative of alkaloids from the extract of the celandine (Chelidonium majus L.) plant. We investigated the effect of Ukrain in animals with lung injury induced by intestinal I/R. Adult male Spraque-Dawley rats were randomly divided into four groups: control, Ukrain, I/R, I/R with Ukrain. Before intestinal I/R was induced, Ukrain was administered intraperitoneally at a dose of 7.0 mg/body weight. After 1 h ischemia and 2 h reperfusion period, lung tissues were excised. Tissue levels of total oxidative status (TOS), total antioxidant status (TAS) were measured and oxidative stress indices (OSI) were calculated. Lung tissues were also examined histopathologically. TOS and OSI levels markedly increased and TAS levels decreased in the I/R group compared to the control group (P < 0.05). TOS and OSI levels markedly decreased and TAS levels increased in the I/R with Ukrain group compared with the group subjected to IR only (P < 0.05). Severe hemorrhage, alveolar septal thickening, and leukocyte infiltration were observed  in the I/R group. In the I/R with Ukrain group, morphologic changes occurring as a result of lung damage attenuated and histopathological scores reduced compared to the I/R group (P < 0.05). Our results suggest that Ukrain pretreatment could reduce lung injury induced by intestinal I/R induced via anti-inflammatory and antioxidant effects.

Inflammatory targets of therapy in sickle cell disease

Sickle cell disease (SCD) is a monogenic globin disorder characterized by the production of a structurally abnormal hemoglobin (Hb) variant Hb S, which causes severe hemolytic anemia, episodic painful vaso-occlusion, and ultimately end-organ damage. The primary disease pathophysiology is intracellular Hb S polymerization and consequent sickling of erythrocytes. It has become evident for more than several decades that a more complex disease process contributes to the myriad of clinical complications seen in patients with SCD with inflammation playing a central role. Drugs targeting specific inflammatory pathways therefore offer an attractive therapeutic strategy to ameliorate many of the clinical events in SCD. In addition, they are useful tools to dissect the molecular and cellular mechanisms that promote individual clinical events and for developing improved therapeutics to address more challenging clinical dilemmas such as refractoriness to opioids or hyperalgesia. Here, we discuss the prospect of targeting multiple inflammatory pathways implicated in the pathogenesis of SCD with a focus on new therapeutics, striving to link the actions of the anti-inflammatory agents to a defined pathobiology, and specific clinical manifestations of SCD. We also review the anti-inflammatory attributes and the cognate inflammatory targets of hydroxyurea, the only Food and Drug Administration-approved drug for SCD.

Oxidative stress parameters and serum magnesium levels in patients with seasonal allergic conjunctivitis

OBJECTIVE

To evaluate oxidative stress parameters and serum magnesium (Mg) levels in patients with seasonal allergic conjunctivitis (SAC) during the pollen season.

METHODS

This observational cross-sectional study involved 35 patients with SAC without any other ocular and systemic diseases, and 38 consecutive, age- and sex-matched healthy subjects. Serum malondialdehyde (MDA), adjusted ischemia modified albumin (IMA), and Mg levels were quantified, and the results were compared between the groups.

RESULTS

No significant differences were found between the groups with respect to age (p = 0.416) and sex (p = 0.362). Serum MDA and adjusted IMA levels of the subjects with SAC (69.54 ± 7.71 μM and 0.74 ± 0.39 ABSU) were significantly higher than the control group (64.61 ± 5.89 μM and 0.57 ± 0.19 ABSU) (p = 0.002 and p = 0.025, respectively). There was no significant difference for serum Mg levels between the groups (p = 0.177).

CONCLUSION

We demonstrated higher levels of oxidative stress parameters in patients with SAC compared to the control group, which imply a possible role of oxidative stress in the pathogenesis of SAC.

Monitoring dynamic alterations in calcium homeostasis by T1-mapping manganese-enhanced MRI (MEMRI) in the early stage of small intestinal ischemia-reperfusion injury

Manganese-enhanced MRI studies have proven to be useful in monitoring physiological activities associated with calcium ions (Ca(2+)) due to the paramagnetic property of the manganese ion (Mn(2+)), which makes it an excellent probe of Ca(2+) . In this study, we developed a method in which a Mn(2+)-enhanced T1 -map MRI could enable the monitoring of Ca(2+) influx during the early stages of intestinal ischemia-reperfusion (I/R) injury. The Mn(2+) infusion protocol was optimized by obtaining dose-dependent and time-course wash-out curves using a Mn(2+)-enhanced T1-map MRI of rabbit abdomens following an intravenous infusion of 50 mmol/l MnCl2 (5-10 nmol/g body weight (BW)). In the rabbit model of intestinal I/R injury, T1 values were derived from the T1 maps in the intestinal wall region and revealed a relationship between the dose of the infused MnCl2 and the intestinal wall relaxation time. Significant Mn(2+) clearance was also observed over time in control animals after the infusion of Mn(2+) at a dose of 10 nmol/g BW. This technique was also shown to be sensitive enough to monitor variations in calcium ion homeostasis in vivo after small intestinal I/R injury. The T1 values of the intestinal I/R group were significantly lower (P < 0.05) than that of the control group at 5, 10, and 15 min after Mn(2+) infusion. Our data suggest that MnCl2 has the potential to be an MRI contrast agent that can be effectively used to monitor changes in intracellular Ca(2+) homeostasis during the early stages of intestinal I/R injury.

Effect of protective solutions and hydroxyethyl starch in the attenuation of the injuries of ischemia and reperfusion of splanchnic organs

PURPOSE

Vogt´s antioxidant solution (red blood cells, Ringer's solution, sodium bicarbonate, mannitol, allopurinol and 50% glucose) or its modification including hydroxyethyl starch (HES) were tested for the prevention of splanchnic artery occlusion shock.

METHODS

Seventy rats were distributed in treatment (3), control (1), and sham (3) groups. Ischemia and reperfusion were induced by celiac, superior mesenteric and inferior mesenteric arteries occlusion for 40 min, followed by 60 min reperfusion or sham procedures. Controls received saline, both treatment and sham groups received the Vogt's solution, modified Vogt's solution (replacing Ringer's solution by HES), or HES. Mean arterial blood pressure (MABP), ileal malondialdehyde (MDA) and plasmatic MDA were determined, and a histologic grading system was used.

RESULTS

At reperfusion, MABP dropped in all I/R groups. Only HES treatment was able to restore final MABP to the levels of sham groups. Plasmatic MDA did not show differences between groups. Ileum MDA was significantly higher in the control and treatment groups as compared to the sham group. Histology ranking was higher in the only in control group.

CONCLUSIONS

Hydroxyethyl starch was able to prevent hemodynamic shock but not intestinal lesions. Both treatments with Vogt's solutions did not show any improvement.

Sevoflurane ameliorates intestinal ischemia-reperfusion-induced lung injury by inhibiting the synergistic action between mast cell activation and oxidative stress

Preconditioning with sevoflurane (SEV) can protect against ischemia-reperfusion injury in several organs, however, the benefits of SEV against acute lung injury (ALI), induced by intestinal ischemia-reperfusion (IIR), and the underlying mechanisms remain to be elucidated. The present study was designed to investigate the effects of SEV preconditioning on IIR-mediated ALI and the associated mechanisms in a rat model. Female Sprague-Dawley rats treated with 2.3% SEV or apocynin (AP), an inhibitor of NADPH oxidase, were subjected to 75 min superior mesenteric artery occlusion followed by 2 h reperfusion in the presence or absence of the mast cell degranulator compound 48/80 (CP). SEV and AP were observed to downregulate the protein expression levels of p47^phox and gp91^phox in the lungs of normal rats. IIR resulted in severe lung injury, characterized by significant increases in pathological injury scores, lung wet/dry weight ratio, protein expression levels of p47^phox, gp91^phox and ICAM-1, the presence of hydrogen peroxide, malondydehyde and interleukin-6, and the activity of myeloperoxidase. In addition, significant reductions were observed in the expression of prosurfactant protein C, accompanied by an increase in MC degranulation, demonstrated by significant elevations in the number of mast cells, expression levels of tryptase and the concentration of β-hexosaminidase. These changes were further augmented in the presence of CP. In addition, SEV and AP preconditioning significantly alleviated the above alterations induced by IIR alone or in combination with CP. These findings suggested that SEV and AP attenuated IIR-induced ALI by inhibiting NADPH oxidase and the synergistic action between oxidative stress and mast cell activation.