Antioxidant strategies in respiratory medicine

Therapeutic importance of Kigelia africana subsp. africana: an alternative medicine

AIM

To summarise a detailed up-to-date review of the traditional uses, phytoconstituents, and pharmacological activities of various parts of Kigelia africana.

MATERIALS AND METHODS

Google Scholar, PubMed, PubChem, Elsevier, King Draw, indianbiodiversity.org.

RESULT

The phytochemical analysis of Kigelia africana subsp. africana has revealed the presence of approximately 145 compounds extracted from different parts of the plant. These bioactive extracts of the plant possess anti-inflammatory, antioxidant, antimicrobial, antidiabetic, antineoplastic, and anti-urolithic activities. Due to its anti-inflammatory, antioxidant, and immune-booster properties, Kigelia can prove to be an essential source of drugs for treating various disorders.

CONCLUSION

Knowledge of the phytoconstituents, non-medicinal and medicinal traditional uses, pharmacological activities, and products obtained from Kigelia is described in this review with the hope that the updated findings will promote research on its biological pathways.

Application of Recombinant Human Superoxide Dismutase in Radical Concurrent Chemoradiotherapy for Cervical Cancer to Prevent and Treat Radiation-induced Acute Rectal Injury: A Multicenter, Randomized, Open-label, Prospective Trial

PURPOSE

The purpose of this study was to evaluate the efficacy of recombinant human superoxide dismutase (rhSOD) enemas in radiation-induced acute rectal injury (RARI) in patients with locally advanced cervical cancer.

METHODS AND MATERIALS

In this phase 3, randomized, open-label trial (NCT04819685) conducted across 14 medical centers in China from June 2021 to August 2023, all patients received concurrent chemoradiation therapy (CCRT). The experimental group was treated with a rhSOD enema during chemoradiation therapy, and the control group had no enema. The Common Terminology Criteria for Adverse Events (version 5.0) was used to evaluate radiation therapy-induced side effects. Endoscopic appearance was assessed using the Vienna Rectoscopy Score. The primary endpoint in the acute phase was the occurrence rate and duration of grade ≥1 (≥G1) diarrhea during CCRT. Secondary endpoints included the occurrence rate and duration of ≥G2 and ≥G3 diarrhea, ≥G1 and ≥G2 diarrhea lasting at least 3 days, and damage to the rectal mucosa due to radiation therapy measured by endoscopy.

RESULTS

Two hundred and eighty-three patients were randomly divided into the experimental (n = 141) or control group (n = 142). The mean number of ≥G1 and ≥G2 diarrhea days were significantly lower in the experimental group than in the control group (3.5 and 0.8 days vs 14.8 and 4.5 days, respectively; P < .001). The incidence of ≥G2 diarrhea decreased from 53.6% to 24.1% when rhSOD enemas were used. Use of antidiarrheals was lower in the experimental group (36.2% vs 55.7%, P < .001). Three patients felt intolerable or abdominal pain after rhSOD enema. RARI grades in the experimental group tended to be lower than those in the control group (P = .061). Logistic regression analysis revealed that rhSOD enema was associated with a lower occurrence rate of ≥G1/2 diarrhea for at least 3 days (P < .001).

CONCLUSIONS

The results of this study suggest that rhSOD enema is safe and significantly reduces the incidence, severity, and duration of RARI, protecting the rectal mucosa.

Ionizing Radiation-Induced Oxidative Stress in Computed Tomography-Effect of Vitamin C on Prevention of DNA Damage: PREVIR-C Randomized Controlled Trial Study Protocol

Exposure to ionizing radiation (IR) is inevitable in various X-ray imaging examinations, with computed tomography (CT) being a major contributor to increased human radiation exposure. Ionizing radiation may cause structural damage to macromolecules, particularly DNA, mostly through an indirect pathway in diagnostic imaging. The indirect pathway primarily involves the generation of reactive oxygen species (ROS) due to water radiolysis induced by IR, leading to DNA damage, including double-strand breaks (DSB), which are highly cytotoxic. Antioxidants, substances that prevent oxidative damage, are proposed as potential radioprotective agents. This Study Protocol article presents the rationale for selecting vitamin C as a preventive measure against CT-associated IR-induced DNA damage, to be investigated in a randomized placebo-controlled trial, with a full in vivo design, using an oral easy-to-use schedule administration in the outpatient setting, for the single CT examination with the highest total global IR dose burden (contrast-enhanced abdomen and pelvis CT). The study also aims to explore the mediating role of oxidative stress, and it has been written in adherence to the Standard Protocol Items recommendations.

Possible modulating functions of probiotic Lactiplantibacillus plantarum in particulate matter-associated pulmonary inflammation

Pulmonary disease represents a substantial global health burden. Increased air pollution, especially fine particulate matter (PM2.5) is the most concerned proportion of air pollutants to respiratory health. PM2.5 may carry or combine with other toxic allergens and heavy metals, resulting in serious respiratory allergies and anaphylactic reactions in the host. Available treatment options such as antihistamines, steroids, and avoiding allergens/dust/pollutants could be limited due to certain side effects and immense exposure to air pollutants, especially in most polluted countries. In this mini-review, we summarized how PM2.5 triggers respiratory hyperresponsiveness and inflammation, and the probiotic Lactiplantibacillus plantarum supplementation could minimize the risk of the same. L. plantarum may confer beneficial effects in PM2.5-associated pulmonary inflammation due to significant antioxidant potential. We discussed L. plantarum's effect on PM2.5-induced reactive oxygen species (ROS), inflammatory cytokines, lipid peroxidation, and DNA damage. Available preclinical evidence shows L. plantarum induces gut-lung axis, SCFA, GABA, and other neurotransmitter signaling via gut microbiota modulation. SCFA signals are important in maintaining lung homeostasis and regulating intracellular defense mechanisms in alveolar cells. However, significant research is needed in this direction to contemplate L. plantarum's therapeutic potential in pulmonary allergies.

Novel Antioxidant Peptides Identified from Arthrospira platensis Hydrolysates Prepared by a Marine Bacterium Pseudoalteromonas sp. JS4-1 Extracellular Protease

Crude enzymes produced by a marine bacterium Pseudoalteromonas sp. JS4-1 were used to hydrolyze phycobiliprotein. Enzymatic productions showed good performance on DPPH radical and hydroxyl radical scavenging activities (45.14 ± 0.43% and 65.11 ± 2.64%, respectively), especially small peptides with MWCO <3 kDa. Small peptides were fractioned to four fractions using size-exclusion chromatography and the second fraction (F2) had the highest activity in hydroxyl radical scavenging ability (62.61 ± 5.80%). The fraction F1 and F2 both exhibited good antioxidant activities in oxidative stress models in HUVECs and HaCaT cells. Among them, F2 could upregulate the activities of SOD and GSH-Px and reduce the lipid peroxidation degree to scavenge the ROS to protect Caenorhabditis elegans under adversity. Then, 25 peptides total were identified from F2 by LC-MS/MS, and the peptide with the new sequence of INSSDVQGKY as the most significant component was synthetized and the ORAC assay and cellular ROS scavenging assay both illustrated its excellent antioxidant property.

Reactive Oxygen Species Scavenging Nanomedicine for the Treatment of Ischemic Heart Disease

Ischemic heart disease (IHD) is the leading cause of disability and mortality worldwide. Reactive oxygen species (ROS) have been shown to play key roles in the progression of diabetes, hypertension, and hypercholesterolemia, which are independent risk factors that lead to atherosclerosis and the development of IHD. Engineered biomaterial-based nanomedicines are under extensive investigation and exploration, serving as smart and multifunctional nanocarriers for synergistic therapeutic effect. Capitalizing on cell/molecule-targeting drug delivery, nanomedicines present enhanced specificity and safety with favorable pharmacokinetics and pharmacodynamics. Herein, the roles of ROS in both IHD and its risk factors are discussed, highlighting cardiovascular medications that have antioxidant properties, and summarizing the advantages, properties, and recent achievements of nanomedicines that have ROS scavenging capacity for the treatment of diabetes, hypertension, hypercholesterolemia, atherosclerosis, ischemia/reperfusion, and myocardial infarction. Finally, the current challenges of nanomedicines for ROS-scavenging treatment of IHD and possible future directions are discussed from a clinical perspective.

Expanding the arsenal against pulmonary diseases using surface-functionalized polymeric micelles: breakthroughs and bottlenecks

Pulmonary diseases such as lung cancer, asthma and tuberculosis have remained one of the common challenges globally. Polymeric micelles (PMs) have emerged as an effective technique for achieving targeted drug delivery for a local as well as a systemic effect. These PMs encapsulate and protect hydrophobic drugs, increase pulmonary targeting, decrease side effects and enhance drug efficacy through the inhalation route. In the current review, emphasis has been placed on the different barriers encountered by the drugs given via the pulmonary route and the mechanism of PMs in achieving drug targeting. The applications of PMs in different pulmonary diseases have also been discussed in detail.

Therapeutic Efficacies of Berberine against Neurological Disorders: An Update of Pharmacological Effects and Mechanisms

Neurological disorders are ranked as the leading cause of disability and the second leading cause of death worldwide, underscoring an urgent necessity to develop novel pharmacotherapies. Berberine (BBR) is a well-known phytochemical isolated from a number of medicinal herbs. BBR has attracted much interest for its broad range of pharmacological actions in treating and/or managing neurological disorders. The discoveries in basic and clinical studies of the effects of BBR on neurological disorders in the last decade have provided novel evidence to support the potential therapeutical efficacies of BBR in treating neurological diseases. In this review, we summarized the pharmacological properties and therapeutic applications of BBR against neurological disorders in the last decade. We also emphasized the major pathways modulated by BBR, which provides firm evidence for BBR as a promising drug candidate for neurological disorders.

The Adverse Impact of Incense Smoke on Human Health: From Mechanisms to Implications

Incense burning is a very popular activity in daily life among many parts all over the world. A growing body of both epidemiological and experimental evidences has reported the negative effects of incense use on human well-being, posing a potential threat at public significance. This work is a comprehensive review that covers the latest findings regarding the adverse impact of incense smoke on our health, providing a panoramic visualization ranging from mechanisms to implications. The toxicities of incense smoke come directly from its harmful constituents and deposition capacity in the body. Besides, reactive oxygen species-driven oxidative stress and associated inflammation seem to be plausible underlying mechanisms, eliciting various unfavorable responses. Although our current knowledge remains many gaps, this issue still has some important implications.

Smart Layer-by-Layer Polymeric Microreactors: pH-Triggered Drug Release and Attenuation of Cellular Oxidative Stress as Prospective Combination Therapy

Polymer capsules fabricated via the layer-by-layer (LbL) approach have emerged as promising biomedical systems for the release of a wide variety of therapeutic agents, owing to their tunable and controllable structure and the possibility to include several functionalities in the polymeric membrane during the fabrication process. However, the limitation of the capsules with a single functionality to overcome the challenges involved in the treatment of complex pathologies denotes the need to develop multifunctional capsules capable of targeting several mediators and/or mechanisms. Oxidative stress is caused by the accumulation of reactive oxygen species [e.g., hydrogen peroxide (H2O2), hydroxyl radicals (•OH), and superoxide anion radicals (•O2-)] in the cellular microenvironment and is a key modulator in the pathology of a broad range of inflammatory diseases. The disease microenvironment is also characterized by the presence of proinflammatory cytokines, increased levels of matrix metalloproteinases, and acidic pH, all of which could be exploited to trigger the release of therapeutic agents. In the present work, multifunctional capsules were fabricated via the LbL approach. Capsules were loaded with an antioxidant enzyme (catalase) and functionalized with a model drug (doxorubicin), which was conjugated to an amine-containing dendritic polyglycerol through a pH-responsive linker. These capsules efficiently scavenge H2O2 from solution, protecting cells from oxidative stress, and release the model drug in acidic microenvironments. Accordingly, in this work, a polymeric microplatform is presented as an unexplored combinatorial approach applicable for multiple targets of inflammatory diseases, in order to perform controlled spatiotemporal enzymatic reactions and drug release in response to biologically relevant stimuli.

Prospective role of thyroid disorders in monitoring COVID-19 pandemic

COVID-19 pandemic has affected more than 200 countries and 1.3 million individuals have deceased within eleven months. Intense research on COVID-19 occurrence and prevalence enable us to understand that comorbidities play a crucial role in spread and severity of SARS-CoV-2 infection. Chronic kidney disease, diabetes, respiratory diseases and hypertension are among the various morbidities that are prevalent in symptomatic COVID-19 patients. However, the effect of altered thyroid-driven disorders cannot be ignored. Since thyroid hormone critically coordinate and regulate the major metabolism and biochemical pathways, this review is on the potential role of prevailing thyroid disorders in SARS-CoV-2 infection. Direct link of thyroid hormone with several disorders such as diabetes, vitamin D deficiency, obesity, kidney and liver disorders etc. suggests that the prevailing thyroid conditions may affect SARS-CoV-2 infection. Further, we discuss the oxidative stress-induced aging is associated with the degree of SARS-CoV-2 infection. Importantly, ACE2 protein which facilitates the host-cell entry of SARS-CoV-2 using the spike protein, are highly expressed in individuals with abnormal level of thyroid hormone. Altogether, we report that the malfunction of thyroid hormone synthesis may aggravate SARS-CoV-2 infection and thus monitoring the thyroid hormone may help in understanding the pathogenesis of COVID-19.

Evaluation of the effects of fear and anxiety on nutrition during the COVID-19 pandemic in Turkey

Objective:

The aim of this study was to evaluate effects of fear and anxiety on nutrition during the COVID-19 pandemic.

Design:

Participants were recruited by an online survey in this cross-sectional study. The questionnaire included general demographic characteristics, level of fear and anxiety, and nutritional habits. The Fear of COVID-19 Scale (FCV-19S) and Generalized Anxiety Disorder-7 test (GAD-7) were used to determine fear and anxiety.

Setting:

Turkey.

Participants:

A total sample consisted of 1012 adults.

Results:

In pandemic, fear and anxiety caused individuals to skip breakfast and snacks less, but more at lunch. A positive significant correlation was observed between the increased consumption of yoghurt, cheese and water and FCV-19S scores. There was a positive significant correlation between cheese, legume, nuts-seeds, cake-cookies, dessert and tea consumption and GAD-7 scores. A 1-unit increase in FCV-19S scores affected 1·04 times of increased consumption of yoghurt, kefir, cheese, nuts-seeds, fruit (dry) and rice-pasta. A 1-unit increase in GAD-7 scores affected 1·03 times of increased consumption of egg and fruit (fresh); 1·04 times of increased consumption of cheese and other vegetables; 1·05 times of increased consumption of milk, meat, poultry, fish, legume, nuts-seeds, fruit (dry), cake-cookies and tea; 1·07 times of increased consumption of rice-pasta and coffee and 1·08 times of increased consumption of bread and dessert.

Conclusions:

In pandemic, anxiety and fear led to changes in individuals’ nutritional habits and food preferences. Continuous surveillance of psychological consequences for outbreaks should become routine as part of preparedness efforts worldwide. In addition, the effects of these psychological problems on nutrition should be evaluated.

Investigating Disturbances of Oxygen Homeostasis: From Cellular Mechanisms to the Clinical Practice

Soon after its discovery in the 18th century, oxygen was applied as a therapeutic agent to treat severely ill patients. Lack of oxygen, commonly termed as hypoxia, is frequently encountered in different disease states and is detrimental to human life. However, at the end of the 19th century, Paul Bert and James Lorrain Smith identified what is known as oxygen toxicity. The molecular basis of this phenomenon is oxygen's readiness to accept electrons and to form different variants of aggressive radicals that interfere with normal cell functions. The human body has evolved to maintain oxygen homeostasis by different molecular systems that are either activated in the case of oxygen under-supply, or to scavenge and to transform oxygen radicals when excess amounts are encountered. Research has provided insights into cellular mechanisms of oxygen homeostasis and is still called upon in order to better understand related diseases. Oxygen therapy is one of the prime clinical interventions, as it is life saving, readily available, easy to apply and economically affordable. However, the current state of research also implicates a reconsidering of the liberal application of oxygen causing hyperoxia. Increasing evidence from preclinical and clinical studies suggest detrimental outcomes as a consequence of liberal oxygen therapy. In this review, we summarize concepts of cellular mechanisms regarding different forms of disturbed cellular oxygen homeostasis that may help to better define safe clinical application of oxygen therapy.

Is Antioxidant Therapy a Useful Complementary Measure for Covid-19 Treatment? An Algorithm for Its Application

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causes the corona virus disease-19 which is accompanied by severe pneumonia, pulmonary alveolar collapses and which stops oxygen exchange. Viral transmissibility and pathogenesis depend on recognition by a receptor in the host, protease cleavage of the host membrane and fusion. SARS-CoV-2 binds to the angiotensin converting enzyme 2 receptor. Here, we discuss the general characteristics of the virus, its mechanism of action and the way in which the mechanism correlates with the comorbidities that increase the death rate. We also discuss the currently proposed therapeutic measures and propose the use of antioxidant drugs to help patients infected with the SARS-CoV-2. Oxidizing agents come from phagocytic leukocytes such as neutrophils, monocytes, macrophages and eosinophils that invade tissue. Free radicals promote cytotoxicity thus injuring cells. They also trigger the mechanism of inflammation by mediating the activation of NFkB and inducing the transcription of cytokine production genes. Release of cytokines enhances the inflammatory response. Oxidative stress is elevated during critical illnesses and contributes to organ failure. In corona virus disease-19 there is an intense inflammatory response known as a cytokine storm that could be mediated by oxidative stress. Although antioxidant therapy has not been tested in corona virus disease-19, the consequences of antioxidant therapy in sepsis, acute respiratory distress syndrome and acute lung injury are known. It improves oxygenation rates, glutathione levels and strengthens the immune response. It reduces mechanical ventilation time, the length of stay in the intensive care unit, multiple organ dysfunctions and the length of stay in the hospital and mortality rates in acute lung injury/acute respiratory distress syndrome and could thus help patients with corona virus disease-19.

Targeting drug delivery in the vascular system: Focus on endothelium

The bloodstream is the main transporting pathway for drug delivery systems (DDS) from the site of administration to the intended site of action. In many cases, components of the vascular system represent therapeutic targets. Endothelial cells, which line the luminal surface of the vasculature, play a tripartite role of the key target, barrier, or victim of nanomedicines in the bloodstream. Circulating DDS may accumulate in the vascular areas of interest and in off-target areas via mechanisms bypassing specific molecular recognition, but using ligands of specific vascular determinant molecules enables a degree of precision, efficacy, and specificity of delivery unattainable by non-affinity DDS. Three decades of research efforts have focused on specific vascular targeting, which have yielded a multitude of DDS, many of which are currently undergoing a translational phase of development for biomedical applications, including interventions in the cardiovascular, pulmonary, and central nervous systems, regulation of endothelial functions, host defense, and permeation of vascular barriers. We discuss the design of endothelial-targeted nanocarriers, factors underlying their interactions with cells and tissues, and describe examples of their investigational use in models of acute vascular inflammation with an eye on translational challenges.

Functional Role of Dietary Intervention to Improve the Outcome of COVID-19: A Hypothesis of Work

BACKGROUND

On the 31 December 2019, the World Health Organization (WHO) was informed of a cluster of cases of pneumonia of unknown origin detected in Wuhan City, Hubei Province, China. The infection spread first in China and then in the rest of the world, and on the 11th of March, the WHO declared that COVID-19 was a pandemic. Taking into consideration the mortality rate of COVID-19, about 5-7%, and the percentage of positive patients admitted to intensive care units being 9-11%, it should be mandatory to consider and take all necessary measures to contain the COVID-19 infection. Moreover, given the recent evidence in different hospitals suggesting IL-6 and TNF-α inhibitor drugs as a possible therapy for COVID-19, we aimed to highlight that a dietary intervention could be useful to prevent the infection and/or to ameliorate the outcomes during therapy. Considering that the COVID-19 infection can generate a mild or highly acute respiratory syndrome with a consequent release of pro-inflammatory cytokines, including IL-6 and TNF-α, a dietary regimen modification in order to improve the levels of adiponectin could be very useful both to prevent the infection and to take care of patients, improving their outcomes.

Ellagic acid ameliorates lung damage in rats via modulating antioxidant activities, inhibitory effects on inflammatory mediators and apoptosis-inducing activities

Phytochemicals is considered one of the most effective and safe alternative therapy against oxidative linked lung diseases. Ellagic acid (EA), an important component of fruits, nuts, and vegetables, are partly responsible for their beneficial health effects against oxidation-related diseases. In the present study, we investigated the ameliorative effect of EA on lung damage induced by carbon tetrachloride (CCl₄) in Wistar male albino rats. Thirty-six male rats (n = 36, 8-week old) were divided into 4 groups, each with 9 rats. The groups were: Control group: received standard diet; EA group: administered with EA (10 mg/kg body weight, intraperitoneal); CCl₄ group: administered with CCl₄ (1.5 mg/kg body weight, intraperitoneal); EA+CCl₄ group: administered with EA and CCl₄. . The rats were decapitated at the end of experimental period of 8 weeks and the lung tissues were examined. CCl₄-induced rats showed elevation in the expressions of inflammatory proteins, nuclear factor kappa b (NF-κB), cyclooxygenase-2 (COX-2), and pro-inflammatory cytokine, tumor necrosis factor alpha (TNF-α); and the indicator of lipid peroxidation, malondialdehyde (MDA). Intraperitoneal administration of EA significantly reduced the levels of these markers. EA administration increased the protein expression levels of nuclear factor erythroid 2-related factor 2 (Nrf-2) and enhanced the activity of glutathione (GSH) and catalase enzyme (CAT). In addition, EA administration increased the expression levels of the executioner protein of apoptosis, caspase-3, and decreasing pro-survival protein, B cell lymphoma-2 (Bcl-2). In conclusion, these results establishes the protective role of EA in the treatment of lung damage and that in the future, this may have the potential to be used as a medication for the prevention or attenuation of lung diseases. Graphical abstract.

Short-Term versus Long-Term Culture of A549 Cells for Evaluating the Effects of Lipopolysaccharide on Oxidative Stress, Surfactant Proteins and Cathelicidin LL-37

Alveolar epithelial type II (ATII) cells and their proper function are essential for maintaining lung integrity and homeostasis. However, they can be damaged by lipopolysaccharide (LPS) during Gram-negative bacterial infection. Thus, this study evaluated and compared the effects of LPS on short and long-term cultures of A549 cells by determining the cell viability, levels of oxidative stress and antimicrobial peptide cathelicidin LL-37 and changes in the expression of surfactant proteins (SPs). Moreover, we compared A549 cell response to LPS in the presence of different serum concentrations. Additionally, the effect of N-acetylcysteine (NAC) on LPS-induced oxidative stress as a possible treatment was determined. Our results indicate that A549 cells are relatively resistant to LPS and able to maintain integrity even at high LPS concentrations. Their response to endotoxin is partially dependent on serum concentration. NAC failed to lower LPS-induced oxidative stress in A549 cells. Finally, LPS modulates SP gene expression in A549 cells in a time dependent manner and differences between short and long-term cultures were present. Our results support the idea that long-term cultivation of A549 cells could promote a more ATII-like phenotype and thus could be a more suitable model for ATII cells, especially for in vitro studies dealing with surfactant production.

Recombinant Human Superoxide Dismutase and N-Acetylcysteine Addition to Exogenous Surfactant in the Treatment of Meconium Aspiration Syndrome

This study aimed to evaluate the molecular background of N-acetylcysteine (NAC) and recombinant human superoxide dismutase (rhSOD) antioxidant action when combined with exogenous surfactant in the treatment of meconium aspiration syndrome (MAS), considering redox signalling a principal part of cell response to meconium. Young New Zealand rabbits were instilled with meconium suspension (Mec) and treated by surfactant alone (Surf) or surfactant in combination with i.v. NAC (Surf + NAC) or i.t. rhSOD (Surf + SOD), and oxygen-ventilated for 5 h. Dynamic lung-thorax compliance, mean airway pressure, PaO₂/FiO₂ and ventilation efficiency index were evaluated every hour; post mortem, inflammatory and oxidative markers (advanced oxidation protein products, total antioxidant capacity, hydroxynonenal (HNE), p38 mitogen activated protein kinase, caspase 3, thromboxane, endothelin-1 and secretory phospholipase A₂) were assessed in pulmonary tissue homogenates. rhSOD addition to surfactant improved significantly, but transiently, gas exchange and reduced levels of inflammatory and oxidative molecules with higher impact; Surf + NAC had stronger effect only on HNE formation, and duration of treatment efficacy in respiratory parameters. In both antioxidants, it seems that targeting reactive oxygen species may be strong supporting factor in surfactant treatment of MAS due to redox sensitivity of many intracellular pathways triggered by meconium.

Short-duration hyperoxia causes genotoxicity in mouse lungs: protection by volatile anesthetic isoflurane

High concentrations of oxygen (hyperoxia) are routinely used during anesthesia, and supplemental oxygen is also administered in connection with several other clinical conditions. Although prolonged hyperoxia is known to cause acute lung injury (ALI), whether short-duration hyperoxia causes lung toxicity remains unknown. We exposed mice to room air (RA or 21% O₂) or 60% oxygen alone or in combination with 2% isoflurane for 2 h and determined the expression of oxidative stress marker genes, DNA damage and DNA repair genes, and expression of cell cycle regulatory proteins using quantitative PCR and Western analyses. Furthermore, we determined cellular apoptosis using TUNEL assay and assessed the DNA damage product 8-hydroxy-2'-deoxyguanosine (8-Oxo-dG) in the urine of 60% hyperoxia-exposed mice. Our study demonstrates that short-duration hyperoxia causes mitochondrial and nuclear DNA damage and that isoflurane abrogates this DNA damage and decreases apoptosis when used in conjunction with hyperoxia. In contrast, isoflurane mixed with RA caused significant 8-Oxo-dG accumulations in the mitochondria and nucleus. We further show that whereas NADPH oxidase is a major source of superoxide anion generated by isoflurane in normoxia, isoflurane inhibits superoxide generation in hyperoxia. Additionally, isoflurane also protected the mouse lungs against ALI (95% O₂ for 36-h exposure). Our study established that short-duration hyperoxia causes genotoxicity in the lungs, which is abrogated when hyperoxia is used in conjunction with isoflurane, but isoflurane alone causes genotoxicity in the lung when delivered with ambient air.

Novel mechanisms regulating endothelial barrier function in the pulmonary microcirculation

The pulmonary epithelial and vascular endothelial cell layers provide two sequential physical and immunological barriers that together form a semi-permeable interface and prevent alveolar and interstitial oedema formation. In this review, we focus specifically on the continuous endothelium of the pulmonary microvascular bed that warrants strict control of the exchange of gases, fluid, solutes and circulating cells between the plasma and the interstitial space. The present review provides an overview of emerging molecular mechanisms that permit constant transcellular exchange between the vascular and interstitial compartment, and cause, prevent or reverse lung endothelial barrier failure under experimental conditions, yet with a clinical perspective. Based on recent findings and at times seemingly conflicting results we discuss emerging paradigms of permeability regulation by altered ion transport as well as shifts in the homeostasis of sphingolipids, angiopoietins and prostaglandins.

Protective Effect of Jianpiyifei II Granule against Chronic Obstructive Pulmonary Disease via NF-κB Signaling Pathway

Jianpiyifei II granule (JPYF II) is an oriental herbal formula used clinically in China to treat chronic obstructive pulmonary disease (COPD). The aim of the present study was to investigate the anti-inflammatory and antioxidative activities of JPYF II in a mouse model of COPD induced by lipopolysaccharide (LPS) and cigarette smoke (CS) and in RAW264.7 cells stimulated with cigarette smoke extract (CSE). Mice were given LPS via intratracheal instillation on days 1 and 15 and exposed to CS generated from 4 cigarettes/day for 28 days. The mice were treated with 0.75, 1.5, or 3 g/kg/d JPYF II by intragastric administration in low, middle, and high dose groups, respectively, for two weeks. RAW264.7 cells were stimulated by CSE and treated with JPYF II at doses of 12.5, 25, or 50 μg/mL. In the mouse model of LPS and CS-induced COPD, JPYF II decreased inflammatory cell counts in broncho alveolar lavage fluid (BALF), in addition to mRNA expression of proinflammatory cytokines and metalloproteinases (MMPs) in lung tissues. In addition, JPYF II elevated catalase (CAT) and glutathione peroxidase (GSH-Px) activities and reduced the levels of malondialdehyde (MDA) and IκBα and p65 phosphorylation and inflammatory cell infiltration in the lung tissues. In RAW264.7 cells stimulated with CSE, JPYF II inhibited the mRNA levels of inflammatory mediators and the phosphorylation of IκBα and p65. Our results suggest that JPYF II enhanced anti-inflammatory and antioxidative activities in a mouse model of COPD induced by LPS and CS and in RAW264.7 cells stimulated with CSE via inhibition of the NF-κB pathway.

The new frontiers of the targeted interventions in the pulmonary vasculature: precision and safety (2017 Grover Conference Series)

The pulmonary vasculature plays an important role in many lung pathologies, such as pulmonary arterial hypertension, primary graft dysfunction of lung transplant, and acute respiratory distress syndrome. Therapy for these diseases is quite limited, largely due to dose-limiting side effects of numerous drugs that have been trialed or approved. High doses of drugs targeting the pulmonary vasculature are needed due to the lack of specific affinity of therapeutic compounds to the vasculature. To overcome this problem, the field of targeted drug delivery aims to target drugs to the pulmonary endothelial cells, especially those in pathological regions. The field uses a variety of drug delivery systems (DDSs), ranging from nano-scale drug carriers, such as liposomes, to methods of conjugating drugs to affinity moieites, such as antibodies. These DDSs can deliver small molecule drugs, protein therapeutics, and imaging agents. Here we review targeted drug delivery to the pulmonary endothelium for the treatment of pulmonary diseases. Cautionary notes are made of the risk–benefit ratio and safety—parameters one should keep in mind when developing a translational therapeutic.

A Phenolic Acid and Flavonoid Fraction Isolated from Lolium multiflorum Lam. Prevents d-Galactosamine-Induced Liver Damages through the Augmentation of Nrf2 Expression

The aims of this study were to explore whether a phenolic acid and flavonoid fraction (named PAFF) isolated from Lolium multiflorum Lam. protects against d-galactosamine (GalN)-induced liver damages in mice and to investigate the associated mechanisms. ICR mice received oral administration with various concentrations (50, 100, and 200 mg/kg body weight) of PAFF once per 2 days for seven times before intraperitoneal injection with 800 mg/kg GalN. After a day of GalN challenge, blood and tissue samples were analyzed by biochemical, histopathological, real time RT-PCR, and Western blot methods. GalN challenge induced severe damage to hepatocytes with hepatocellular vacuolization and necrosis. GalN treatment increased serum ALT, ALP, AST, and LDH levels and hepatic MDA levels and stimulated mRNA and protein expressions of Nrf2 and HO-1 in the liver. GalN treatment also diminished the levels of GSH and the activities of CAT, SOD, and GPx in the liver. However, combined treatment with PAFF inhibited GalN-mediated increases in the histological damages and the levels of serum enzymes and hepatic MDA, restored the activities of hepatic antioxidant enzymes up to those in the control values, and augmented the GalN-stimulated expression of Nrf2 and HO-1 in the liver. Furthermore, PAFF treatment alone increased the cellular SOD activity and the expression of Nrf2 and HO-1 in the liver. Our results suggest that PAFF may protect against GalN-induced liver damage by decreasing oxidative stress and increasing cellular antioxidant activities through an activation of Nrf2/HO-1-dependent pathway.

Anti-inflammatory and Anti-oxidative Effects of Dexpanthenol on Lipopolysaccharide Induced Acute Lung Injury in Mice

The aim of this study is to investigate the effects of dexpanthenol in a model of acute lung injury (ALI) induced by lipopolysaccharides (LPS). Lung injury was induced by exposure to atomized LPS. Mice were randomly divided into four groups: control group; Dxp (500 mg/kg) group; LPS group; LPS + Dxp (500 mg/kg) group. The effects of dexpanthenol on LPS-induced neutrophil recruitment, cytokine levels, total protein concentration, myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) contents were examined. Additionally, lung tissue was examined by histology to investigate the changes in pathology in the presence and absence of dexpanthenol. In LPS-challenged mice, dexpanthenol significantly improved lung edema. Dexpanthenol also markedly inhibited the LPS-induced neutrophiles influx, protein leakage, and release of TNF-α and IL-6 in bronchoalveolar lavage fluid (BALF). Furthermore, dexpanthenol attenuated MPO activity and MDA contents and increased SOD and GSH activity in the LPS-challenged lung tissue. These data suggest that dexpanthenol protects mice from LPS-induced acute lung injury by its anti-inflammatory and anti-oxidative activities.

Current Antioxidant Treatments in Organ Transplantation

Oxidative stress is one of the key mechanisms affecting the outcome throughout the course of organ transplantation. It is widely believed that the redox balance is dysregulated during ischemia and reperfusion (I/R) and causes subsequent oxidative injury, resulting from the formation of reactive oxygen species (ROS). Moreover, in order to alleviate organ shortage, increasing number of grafts is retrieved from fatty, older, and even non-heart-beating donors that are particularly vulnerable to the accumulation of ROS. To improve the viability of grafts and reduce the risk of posttransplant dysfunction, a large number of studies have been done focusing on the antioxidant treatments for the purpose of maintaining the redox balance and thereby protecting the grafts. This review provides an overview of these emerging antioxidant treatments, targeting donor, graft preservation, and recipient as well.

Targeted endothelial nanomedicine for common acute pathological conditions

Endothelium, a thin monolayer of specialized cells lining the lumen of blood vessels is the key regulatory interface between blood and tissues. Endothelial abnormalities are implicated in many diseases, including common acute conditions with high morbidity and mortality lacking therapy, in part because drugs and drug carriers have no natural endothelial affinity. Precise endothelial drug delivery may improve management of these conditions. Using ligands of molecules exposed to the bloodstream on the endothelial surface enables design of diverse targeted endothelial nanomedicine agents. Target molecules and binding epitopes must be accessible to drug carriers, carriers must be free of harmful effects, and targeting should provide desirable sub-cellular addressing of the drug cargo. The roster of current candidate target molecules for endothelial nanomedicine includes peptidases and other enzymes, cell adhesion molecules and integrins, localized in different domains of the endothelial plasmalemma and differentially distributed throughout the vasculature. Endowing carriers with an affinity to specific endothelial epitopes enables an unprecedented level of precision of control of drug delivery: binding to selected endothelial cell phenotypes, cellular addressing and duration of therapeutic effects. Features of nanocarrier design such as choice of epitope and ligand control delivery and effect of targeted endothelial nanomedicine agents. Pathological factors modulate endothelial targeting and uptake of nanocarriers. Selection of optimal binding sites and design features of nanocarriers are key controllable factors that can be iteratively engineered based on their performance from in vitro to pre-clinical in vivo experimental models. Targeted endothelial nanomedicine agents provide antioxidant, anti-inflammatory and other therapeutic effects unattainable by non-targeted counterparts in animal models of common acute severe human disease conditions. The results of animal studies provide the basis for the challenging translation endothelial nanomedicine into the clinical domain.

Ursolic acid improves survival and attenuates lung injury in septic rats induced by cecal ligation and puncture

BACKGROUND

Sepsis is characterized as a systemic inflammatory response syndrome during infection, which can result in multiple organ dysfunction and death. Ursolic acid (UA), a pentacyclic triterpene acid, has been reported to have potent anti-inflammatory and antioxidant properties. The aim of this study was to detect the possible protective effects of UA on sepsis-evoked acute lung injury.

MATERIALS AND METHODS

A rat model of sepsis induced by cecal ligation and puncture (CLP) was used. Rats were injected intraperitoneally with UA (10 mg/kg) after CLP, and then the survival was determined twice a day for 4 d. The protective effects of UA on CLP-induced acute lung injury were assayed at 24 h after CLP.

RESULTS

The results revealed that UA treatment markedly improved the survival of septic rats, and attenuated CLP-induced lung injury, including reduction of lung wet/dry weight ratio, infiltration of leukocytes and proteins, myeloperoxidase activity, and malondialdehyde content. In addition, UA significantly decreased the serum levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β, inhibited the expression of inducible nitric oxide synthase and cyclooxygenase-2 in the lung, which are involved in the productions of nitric oxide and prostaglandin E2.

CONCLUSIONS

These findings indicate that UA exerts protective effects on CLP-induced septic rats. UA may be a potential therapeutic agent against sepsis.

Mitochondrial DNA damage-associated molecular patterns mediate a feed-forward cycle of bacteria-induced vascular injury in perfused rat lungs

Fragments of the mitochondrial genome released into the systemic circulation after mechanical trauma, termed mitochondrial DNA damage-associated molecular patterns (mtDNA DAMPs), are thought to mediate the systemic inflammatory response syndrome. The close association between circulating mtDNA DAMP levels and outcome in sepsis suggests that bacteria also might be a stimulus for mtDNA DAMP release. To test this hypothesis, we measured mtDNA DAMP abundance in medium perfusing isolated rat lungs challenged with an intratracheal instillation of 5 × 10(7) colony-forming units of Pseudomonas aeruginosa (strain 103; PA103). Intratracheal PA103 caused rapid accumulation of selected 200-bp sequences of the mitochondrial genome in rat lung perfusate accompanied by marked increases in both lung tissue oxidative mtDNA damage and in the vascular filtration coefficient (Kf). Increases in lung tissue mtDNA damage, perfusate mtDNA DAMP abundance, and Kf were blocked by addition to the perfusion medium of a fusion protein targeting the DNA repair enzyme Ogg1 to mitochondria. Intra-arterial injection of mtDNA DAMPs prepared from rat liver mimicked the effect of PA103 on both Kf and lung mtDNA integrity. Effects of mtDNA and PA103 on Kf were also attenuated by an oligodeoxynucleotide inhibitor of Toll-like receptor 9 (TLR-9) by mitochondria-targeted Ogg1 and by addition of DNase1 to the perfusion medium. Collectively, these findings are consistent with a model wherein PA103 causes oxidative mtDNA damage leading to a feed-forward cycle of mtDNA DAMP formation and TLR-9-dependent mtDNA damage that culminates in acute lung injury.

Delivery aspects of antioxidants in diabetes management

INTRODUCTION

Ample research has been done to study the role of oxidative stress due to the generation of excess reactive species in initiation and progression of diabetic complications. A positive result has been indicated hypothesizing that abating this oxidative stress can prove to be an alternate strategy in therapy apart from oral antidiabetic drugs. But these dietary antioxidants are less efficient because of poor solubility, permeability, instability on storage, gastrointestinal degradation and first-pass metabolism.

AREAS COVERED

This review gives a brief insight into the molecular mechanism of oxidative stress in development of diabetic complications. Major hurdles limiting the translation of antioxidants to clinical area are also discussed. Various delivery approaches including both conventional and novel drug delivery systems explored so far for combating these challenges in antioxidant delivery are also explored. Mitochondrial targeting of such molecules is also briefly discussed.

EXPERT OPINION

A thorough study of clinical efficacy and safety of antioxidants on long-term use judging its clinical applicability is required. The clinical success of antioxidants as a therapeutic strategy involves a combination of effective design of drug delivery carrier that are in turn related to their degradation profile, possibility of cellular uptake at defined site of action and so on and clinical and preclinical trials that will provide a base for the design of dose and administration regimen.

Thioredoxin-deficient mice, a novel phenotype sensitive to ambient air and hypersensitive to hyperoxia-induced lung injury

Pulmonary oxygen toxicity is a major clinical problem for patients undergoing supplemental oxygen therapy. Thioredoxin (Trx) is an endogenous antioxidant protein that regenerates oxidatively inactivated proteins. We examined how Trx contributes to oxygen tolerance by creating transgenic mice with decreased levels of functional thioredoxin (dnTrx-Tg) using a dominant-negative approach. These mice showed decreased Trx activity in the lung although the expression of mutant protein is three times higher than the wild-type mice. Additionally, we found that these mice showed increased oxidation of endogenous Trx in room air. When exposed to hyperoxia (>90% O2) for 4 days, they failed to recover and showed significant mortality. Even in normal oxygen levels, these mice displayed a significant decrease in aconitase and NADH dehydrogenase activities, decreased mitochondrial energy metabolism, increased p53 and Gadd45α expression, and increased synthesis of proinflammatory cytokines. These effects were further increased by hyperoxia. We also generated mice overexpressing Trx (Trx-Tg) and found they maintained lung redox balance during exposure to high oxygen and thus were resistant to hyperoxia-induced lung injury. These mice had increased levels of reduced Trx in the lung in normoxia as well as hyperoxia. Furthermore, the levels of aconitase and NADH dehydrogenase activities were maintained in these mice concomitant with maintenance of mitochondrial energy metabolism. The genotoxic stress markers such as p53 or Gadd45α remained in significantly lower levels in hyperoxia compared with dnTrx-Tg or wild-type mice. These studies establish that mice deficient in functional Trx exhibit a phenotype of sensitivity to ambient air and hypersensitivity to hyperoxia.

Novel peptide for attenuation of hyperoxia-induced disruption of lung endothelial barrier and pulmonary edema via modulating peroxynitrite formation

Pulmonary damages of oxygen toxicity include vascular leakage and pulmonary edema. We have previously reported that hyperoxia increases the formation of NO and peroxynitrite in lung endothelial cells via increased interaction of endothelial nitric oxide (eNOS) with β-actin. A peptide (P326TAT) with amino acid sequence corresponding to the actin binding region of eNOS residues 326-333 has been shown to reduce the hyperoxia-induced formation of NO and peroxynitrite in lung endothelial cells. In the present study, we found that exposure of pulmonary artery endothelial cells to hyperoxia (95% oxygen and 5% CO2) for 48 h resulted in disruption of monolayer barrier integrity in two phases, and apoptosis occurred in the second phase. NOS inhibitor N(G)-nitro-L-arginine methyl ester attenuated the endothelial barrier disruption in both phases. Peroxynitrite scavenger uric acid did not affect the first phase but ameliorated the second phase of endothelial barrier disruption and apoptosis. P326TAT inhibited hyperoxia-induced disruption of monolayer barrier integrity in two phases and apoptosis in the second phase. More importantly, injection of P326TAT attenuated vascular leakage, pulmonary edema, and endothelial apoptosis in the lungs of mice exposed to hyperoxia. P326TAT also significantly reduced the increase in eNOS-β-actin association and protein tyrosine nitration. Together, these results indicate that peptide P326TAT ameliorates barrier dysfunction of hyperoxic lung endothelial monolayer and attenuates eNOS-β-actin association, peroxynitrite formation, endothelial apoptosis, and pulmonary edema in lungs of hyperoxic mice. P326TAT can be a novel therapeutic agent to treat or prevent acute lung injury in oxygen toxicity.

Nanocarriers for vascular delivery of anti-inflammatory agents

There is a need for improved treatment of acute vascular inflammation in conditions such as ischemia-reperfusion injury, acute lung injury, sepsis, and stroke. The vascular endothelium represents an important therapeutic target in these conditions. Furthermore, some anti-inflammatory agents (AIAs) (e.g., biotherapeutics) require precise delivery into subcellular compartments. In theory, optimized delivery to the desired site of action may improve the effects and enable new mechanisms of action of these AIAs. Diverse nanocarriers (NCs) and strategies for targeting them to endothelial cells have been designed and explored for this purpose. Studies in animal models suggest that delivery of AIAs using NCs may provide potent and specific molecular interventions in inflammatory pathways. However, the industrial development and clinical translation of complex NC-AIA formulations are challenging. Rigorous analysis of therapeutic/side effect and benefit/cost ratios is necessary to identify and optimize the approaches that may find clinical utility in the management of acute inflammation.

AMPK and FoxO1 regulate catalase expression in hypoxic pulmonary arterial smooth muscle

BACKGROUND

Hypoxia and reactive oxygen species (ROS) including H(2)O(2) play major roles in triggering and progression of pulmonary vascular remodeling in persistent pulmonary hypertension. Catalase (CAT), the major endogenous enzyme scavenging H(2)O(2), is regulated in a tissue- and context-specific manner.

OBJECTIVE

To investigate mechanisms by which hypoxia and H(2)O(2) regulate catalase expression, and the role of AMPK-FoxO pathway, in neonatal porcine pulmonary artery smooth muscle (PASMC).

DESIGN/METHODS

PASMC were grown in hypoxia (10% O(2)) or normoxia (21% O(2)) for 72 hr. We measured catalase activity and lipid peroxidation; CAT, FoxO1, and FoxO3a expression by qPCR; protein contents of CAT, FoxOs, p-AMPK, p-AKT, p-JNK, p-ERK1/2 in whole lysates, and FoxOs in nuclear extracts, by immunoblot; and FoxO-1 nuclear localization by immunocytochemistry, quantified by laser scanning cytometry.

RESULTS

Hypoxia upregulated CAT transcription, content and activity, by increasing CAT transcription factors FoxO1 and FoxO3a mRNA, and promoting nuclear translocation of FoxO1. However, lipid peroxidation increased in hypoxic PASMC. Among candidate FoxO regulatory kinases, hypoxia activated AMPK, and decreased p-Akt and ERK1/2. AMPK activation increased FoxO1 (total and nuclear) and CAT, while AMPK inhibition inhibited FoxO1 and CAT, but not FoxO3a. Exogenous H(2)O(2) decreased p-AMPK and increased p-AKT in hypoxic PASMC. This decreased active FoxO1, and reduced mRNA and protein content of CAT. Hypoxic induction of CAT, AKT inhibition (LY294002), or addition of PEG-catalase partly ameliorated the H(2)O(2) -mediated loss of nuclear FoxO1.

CONCLUSIONS

Hypoxia induces catalase expression, though this adaptation is insufficient to protect PASMC from hypoxia-induced lipid peroxidation. This occurs via hypoxic activation of AMPK, which promotes nuclear FoxO1 and thus catalase expression. Exogenous ROS may downregulate cellular antioxidant defenses; H(2)O(2) activates survival factor Akt, decreasing nuclear FoxO1 and thus catalase.

Targeting to endothelial cells augments the protective effect of novel dual bioactive antioxidant/anti-inflammatory nanoparticles

Oxidative stress and inflammation are intertwined contributors to numerous acute vascular pathologies. A novel dual bioactive nanoparticle with antioxidant/anti-inflammatory properties was developed based on the interactions of tocopherol phosphate and the manganese porphyrin SOD mimetic, MnTMPyP. The size and drug incorporation efficiency were shown to be dependent on the amount of MnTMPyP added as well as the choice of surfactant. MnTMPyP was shown to retain its SOD-like activity while in intact particles and to release in a slow and controlled manner. Conjugation of anti-PECAM antibody to the nanoparticles provided endothelial targeting and potentiated nanoparticle-mediated suppression of inflammatory activation of these cells manifested by expression of VCAM, E-selectin, and IL-8. This nanoparticle technology may find applicability with drug combinations relevant for other pathologies.

Adiponectin protects against hyperoxic lung injury and vascular leak

Adiponectin (Ad), an adipokine exclusively secreted by the adipose tissue, has emerged as a paracrine metabolic regulator as well as a protectant against oxidative stress. Pharmacological approaches of protecting against clinical hyperoxic lung injury during oxygen therapy/treatment are limited. We have previously reported that Ad inhibits the NADPH oxidase-catalyzed formation of superoxide from molecular oxygen in human neutrophils. Based on this premise, we conducted studies to determine whether (i) exogenous Ad would protect against the hyperoxia-induced barrier dysfunction in the lung endothelial cells (ECs) in vitro, and (ii) endogenously synthesized Ad would protect against hyperoxic lung injury in wild-type (WT) and Ad-overexpressing transgenic (AdTg) mice in vivo. The results demonstrated that exogenous Ad protected against the hyperoxia-induced oxidative stress, loss of glutathione (GSH), cytoskeletal reorganization, barrier dysfunction, and leak in the lung ECs in vitro. Furthermore, the hyperoxia-induced lung injury, vascular leak, and lipid peroxidation were significantly attenuated in AdTg mice in vivo. Also, AdTg mice exhibited elevated levels of total thiols and GSH in the lungs as compared with WT mice. For the first time, our studies demonstrated that Ad protected against the hyperoxia-induced lung damage apparently through attenuation of oxidative stress and modulation of thiol-redox status.

Vascular targeting of nanocarriers: perplexing aspects of the seemingly straightforward paradigm

Targeted nanomedicine holds promise to find clinical use in many medical areas. Endothelial cells that line the luminal surface of blood vessels represent a key target for treatment of inflammation, ischemia, thrombosis, stroke, and other neurological, cardiovascular, pulmonary, and oncological conditions. In other cases, the endothelium is a barrier for tissue penetration or a victim of adverse effects. Several endothelial surface markers including peptidases (e.g., ACE, APP, and APN) and adhesion molecules (e.g., ICAM-1 and PECAM) have been identified as key targets. Binding of nanocarriers to these molecules enables drug targeting and subsequent penetration into or across the endothelium, offering therapeutic effects that are unattainable by their nontargeted counterparts. We analyze diverse aspects of endothelial nanomedicine including (i) circulation and targeting of carriers with diverse geometries, (ii) multivalent interactions of carrier with endothelium, (iii) anchoring to multiple determinants, (iv) accessibility of binding sites and cellular response to their engagement, (v) role of cell phenotype and microenvironment in targeting, (vi) optimization of targeting by lowering carrier avidity, (vii) endocytosis of multivalent carriers via molecules not implicated in internalization of their ligands, and (viii) modulation of cellular uptake and trafficking by selection of specific epitopes on the target determinant, carrier geometry, and hydrodynamic factors. Refinement of these aspects and improving our understanding of vascular biology and pathology is likely to enable the clinical translation of vascular endothelial targeting of nanocarriers.

Bioactivities of Compounds from Elephantopus scaber, an Ethnomedicinal Plant from Southwest China

Elephantopus scaber is an ethnomedicinal plant used by the Zhuang people in Southwest China to treat headaches, colds, diarrhea, hepatitis, and bronchitis. A new δ-truxinate derivative, ethyl, methyl 3,4,3′,4′-tetrahydroxy-δ-truxinate (1), was isolated from the ethyl acetate extract of the entire plant, along with 4 known compounds. The antioxidant activity of these 5 compounds was determined by ABTS radical scavenging assay. Compound 1 was also tested for its cytotoxicity effect against HepG2 by MTT assay (IC₅₀ = 60 μM), and its potential anti-inflammatory, antibiotic, and antitumor bioactivities were predicted using target fishing method software.

Acute respiratory distress syndrome induction by pulmonary ischemia-reperfusion injury in large animal models

Acute respiratory distress syndrome (ARDS) is a common critical pulmonary complication after esophagectomy and other thoracic surgeries (e.g., lung transplantation, pulmonary thromboendarterectomy). Direct pulmonary ischemia-reperfusion injury (PIRI) is known to play the main role in induction of ARDS in these cases. Large animal models are an appropriate choice for ARDS as well as PIRI study because of their physiological and anatomic similarities to the human body. With regard to large animal models, we reviewed different methods of inducing in situ direct PIRI and the commonly applied methods for diagnosing and monitoring ARDS or PIRI in an experimental research setting.

Endothelial targeting of liposomes encapsulating SOD/catalase mimetic EUK-134 alleviates acute pulmonary inflammation

Production of excessive levels of reactive oxygen species (ROS) in the vascular endothelium is a common pathogenic pathway in many dangerous conditions, including acute lung injury, ischemia-reperfusion, and inflammation. Ineffective delivery of antioxidants to the endothelium limits their utility for management of these conditions. In this study, we devised a novel translational antioxidant intervention targeted to the vascular endothelium using PEG-liposomes loaded with EUK-134 (EUK), a potent superoxide dismutase/catalase mimetic. EUK loaded into antibody-coated liposomes (size 197.8±4.5 nm diameter, PDI 0.179±0.066) exerted partial activity in the intact carrier, while full activity was recovered upon liposome disruption. For targeting we used antibodies (Abs) to platelet-endothelial cell adhesion molecule (PECAM-1). Both streptavidin-biotin and SATA/SMCC conjugation chemistries provided binding of 125-150 Ab molecules per liposome. Ab/EUK/liposomes, but not IgG/EUK/liposomes: i) bound to endothelial cells and inhibited cytokine-induced inflammatory activation in vitro; and, ii) accumulated in lungs after intravascular injection, providing >60% protection against pulmonary edema in endotoxin-challenged mice (vs <6% protection afforded by IgG/liposome/EUK counterpart). Since the design elements of this drug delivery system are already in clinical use (PEG-liposomes, antibodies, SATA/SMCC conjugation), it is an attractive candidate for translational interventions using antioxidant molecules such as EUK and other clinically acceptable drugs.

Targeted Drug Delivery to Endothelial Adhesion Molecules

Endothelial cells represent important targets for therapeutic and diagnostic interventions in many cardiovascular, pulmonary, neurological, inflammatory, and metabolic diseases. Targeted delivery of drugs (especially potent and labile biotherapeutics that require specific subcellular addressing) and imaging probes to endothelium holds promise to improve management of these maladies. In order to achieve this goal, drug cargoes or their carriers including liposomes and polymeric nanoparticles are chemically conjugated or fused using recombinant techniques with affinity ligands of endothelial surface molecules. Cell adhesion molecules, constitutively expressed on the endothelial surface and exposed on the surface of pathologically altered endothelium—selectins, VCAM-1, PECAM-1, and ICAM-1—represent good determinants for such a delivery. In particular, PECAM-1 and ICAM-1 meet criteria of accessibility, safety, and relevance to the (patho)physiological context of treatment of inflammation, ischemia, and thrombosis and offer a unique combination of targeting options including surface anchoring as well as intra- and transcellular targeting, modulated by parameters of the design of drug delivery system and local biological factors including flow and endothelial phenotype. This review includes analysis of these factors and examples of targeting selected classes of therapeutics showing promising results in animal studies, supporting translational potential of these interventions.

Antioxidant effect of human adult adipose-derived stromal stem cells in alveolar epithelial cells undergoing stretch

INTRODUCTION

Alveolar epithelial cells undergo stretching during mechanical ventilation. Stretch can modify the oxidative balance in the alveolar epithelium. The aim of the present study was to evaluate the antioxidant role of human adult adipose tissue-derived stromal cells (hADSCs) when human alveolar epithelial cells were subjected to injurious cyclic overstretching.

METHODS

A549 cells were subjected to biaxial stretch (0-15% change in surface area for 24h, 0.2Hz) with and without hADSCs. At the end of the experiments, oxidative stress was measured as superoxide generation using positive nuclear dihydroethidium (DHE) staining, superoxide dismutase (SOD) activity in cell lysates, 8-isoprostane concentrations in supernatant, and 3-nitrotyrosine by indirect immunofluorescence in fixed cells.

RESULTS

Cyclically stretching of AECs induced a significant decrease in SOD activity, and an increase in 8-isoprostane concentrations, DHE staining and 3-nitrotyrosine staining compared with non-stretched cells. Treatment with hADSCs significantly attenuated stretch-induced changes in SOD activity, 8-isoprostane concentrations, DHE and 3-nitrotyrosine staining.

CONCLUSION

These data suggest that hADSCs have an anti-oxidative effect in human alveolar epithelial cells undergoing cyclic stretch.

Hyperoxia during one lung ventilation: inflammatory and oxidative responses

BACKGROUND

It is common practice during one lung ventilation (OLV) to use 100% oxygen, although this may cause hyperoxia- and oxidative stress-related lung injury. We hypothesized that lower oxygen (FiO(2) ) during OLV will result in less inflammatory and oxidative lung injury and improved lung function.

METHODS

Twenty pigs (8.88 ± 0.84 kg; 38 ± 4.6 days) were assigned to either the hyperoxia group (n = 10; FiO(2)  = 100%) or the normoxia group (n = 10; FiO(2)  < 50%). Both groups were subjected to 3 hr of OLV. Blood samples were tested for pro-inflammatory cytokines and lung tissue was tested for these cytokines and oxidative biomarkers.

RESULTS

There were no differences between groups for partial pressure of CO(2) , tidal volume, end-tidal CO(2) , plasma cytokines, or respiratory compliance. Total respiratory resistance was greater in the hyperoxia group (P = 0.02). There were higher levels of TNF-α, IL-1β, and IL-6 in the lung homogenates of the hyperoxia group than in the normoxia group (P ≤ 0.01, 0.001, and 0.001, respectively). Myeloperoxidase and protein carbonyls (PC) were higher (P = 0.03 and P = 0.01, respectively) and superoxide dismutase (SOD) was lower in the lung homogenates of the hyperoxia group (P ≤ 0.001).

CONCLUSION

Higher myeloperoxidase, PC, and cytokine levels, and lower SOD availability indicate a greater degree of injury in the lungs of the hyperoxia animals, possibly from using 100% oxygen. In this translational study using a pig model, FiO(2)  ≤ 50% during OLV reduced hyperoxic injury and improved function in the lungs.

The effect of post-treatment N-acetylcysteine in LPS-induced acute lung injury of rats

Background

Oxidation plays an important role in acute lung injury. This study was conducted in order to elucidate the effect of repetitive post-treatment of N-acetylcysteine (NAC) in lipopolysaccaride (LPS)-induced acute lung injury (ALI) of rats.

Methods

Six-week-old male Sprague-Dawley rats were divided into 4 groups. LPS (Escherichia coli 5 mg/kg) was administered intravenously via the tail vein. NAC (20 mg/kg) was injected intraperitoneally 3, 6, and 12 hours after LPS injection. Broncho-alveolar lavage fluid (BALF) and lung tissues were obtained to evaluate the ALI at 24 hours after LPS injection. The concentration of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were measured in BALF. Nuclear factor κB (NF-κB), lipid peroxidation (LPO), and myeloperoxidase (MPO) were measured using lung tissues. Micro-computed tomography (micro-CT) images were examined in each group at 72 hours apart from the main experiments in order to observe the delayed effects of NAC.

Results

TNF-α and IL-1β concentration in BALF were not different between LPS and NAC treatment groups. The concentration of LPO in NAC treatment group was significantly lower than that of LPS group (5.5±2.8 nmol/mL vs. 16.5±1.6 nmol/mL) (p=0.001). The activity of MPO in NAC treatment group was significantly lower than that of LPS group (6.4±1.8 unit/g vs. 11.2±6.3 unit/g, tissue) (p<0.048). The concentration of NF-κB in NAC treatment group was significantly lower than that of LPS group (0.3±0.1 ng/µL vs. 0.4±0.2 ng/µL) (p=0.0001). Micro-CT showed less extent of lung injury in NAC treatment than LPS group.

Conclusion

After induction of ALI with lipopolysaccharide, the therapeutic administration of NAC partially attenuated the extent of ALI through the inhibition of NF-κB activation.

Apoptosis induction of U937 human leukemia cells by diallyl trisulfide induces through generation of reactive oxygen species

BACKGROUND

Diallyl trisulfide (DATS) is one of the major constituents in garlic oil and has demonstrated various pharmacological activities, including antimicrobial, antihyperlipidemic, antithrombotic, and anticancer effects. However, the mechanisms of antiproliferative activity in leukemia cells are not fully understood. In this study, the apoptotic effects of DATS were investigated in human leukemia cells.

RESULTS

Results of this study indicated that treatment with DATS resulted in significantly inhibited leukemia cell growth in a concentration- and time-dependent manner by induction of apoptosis. In U937 cells, DATS-induced apoptosis was correlated with down-regulation of Bcl-2, XIAP, and cIAP-1 protein levels, cleavage of Bid proteins, activation of caspases, and collapse of mitochondrial membrane potential. The data further demonstrated that DATS increased intracellular reactive oxygen species (ROS) generation, which was attenuated by pretreatment with antioxidant N-acetyl-l-cysteine (NAC), a scavenger of ROS. In addition, administration of NAC resulted in significant inhibition of DATS-induced apoptosis by inhibiting activation of caspases.

CONCLUSIONS

The present study reveals that the cytotoxicity caused by DATS is mediated by generation of ROS and subsequent activation of the ROS-dependent caspase pathway in U937 leukemia cells.