Free radicals and inflammation: superoxide-dependent activation of a neutrophil chemotactic factor in plasma

Nuclear factor κB signaling revisited: Its role in skeletal muscle and exercise

Nuclear factor (NF) κB as a redox sensitive, anti-apoptotic and pro-inflammatory signaling molecule has been studied extensively for more than three decades. Its role in inducing antioxidant enzymes, defending against extracellular and intracellular stress and maintaining redox homeostasis in skeletal muscle has also been recognized. New research continues to explore the polytropic nature of NFκB in cellular function, especially its crosstalk with other important signaling pathways. Understanding of the broad impact of these functions has significant implications in health and disease of skeletal muscle as an organ designed for contraction and mobility. Two important aspects of muscle wellbeing, i.e., disease and aging, are not discussed in this review. This review will provide an update on the new findings related to NFκB involvement in multiple signaling pathways and refresh our knowledge of its activation in skeletal muscle with a special reference to physical exercise.

Polyphenols and post-exercise muscle damage: a comprehensive review of literature

Recent research highlights the significant role of polyphenols in alleviating post-exercise muscle damage, thus positioning them as a valuable nutritional strategy for athletes and fitness enthusiasts. Polyphenols, naturally occurring bioactive compounds abundant in fruits, vegetables, tea, wine, and other plant-based foods, are recognized for their potent antioxidant and anti-inflammatory properties. This dual mechanism is critical for combating oxidative stress and inflammation-two factors that intensify during vigorous physical activity and contribute to muscle soreness and damage. Among various polyphenols, compounds like quercetin have particularly emerged as effective agents for promoting muscle recovery and enhancing exercise performance. These protective effects are facilitated through several mechanisms, including the modulation of inflammatory pathways, acceleration of muscle repair processes, and enhancement of mitochondrial function, all of which bolster overall muscle health. As ongoing studies yield deeper insights, the potential of polyphenols to enhance athletic performance and overall health will become increasingly substantiated, leading towards their strategic incorporation into exercise nutrition protocols. Therefore, we reviewed relevant studies in order to show how efficient polyphenols can be in reducing muscle fatigue and damage and what are the exact mechanisms.

Molecular feature of neutrophils in immune microenvironment of muscle atrophy

Homeostasis in skeletal muscle is sustained by the balance of functional and physical interactions between muscle and myofibre microenvironment. Various factors, such as ageing, disuse and denervation, tip the balance and induce skeletal muscle atrophy. Skeletal muscle atrophy, which involves complex physiological and biochemical changes, is accompanied by adverse outcomes and even increased mortality. Multiple studies have investigated the role of neutrophils in atrophied skeletal muscles; however, neutrophil intrusion in muscle is still a polemical knot. As technical obstacles have been overcome, people have gradually discovered new functions of neutrophils. The classical view of neutrophils is no longer applicable to their biological characteristics. To date, no clear association between the hidden injurious effect of neutrophil intrusion and muscle atrophy has been convincingly proven. Throughout this review, we have discussed the neutrophil activities that mediate muscle atrophy for distinct disease occurrences. Hopefully, this review will help both clinicians and researchers of skeletal muscle atrophy with relevant targets to further explore efficient medical interventions and treatments.

Protein expression changes during phagocytosis influenced by low-frequency electromagnetic field exposure

The aim of our studies was to determine the influence of a low-frequency electromagnetic field (EMF) on the phagocytosis of latex beads (LBs) and the expression level of proteins/genes in the human monocytic macrophage Mono Mac 6 (MM6) cell line in in vitro conditions. Before phagocytosis assay cells were pre-stimulated with infectious agents such as lipopolysaccharide (LPS), Staphylococcal enterotoxin B (SEB), or the proliferatory agent phytohaemagglutinin (PHA), and then exposed to EMF (30 mT, 7 Hz, 3 h). The expression of cytoplasmic proteins like iPLA, cPLA, iNOS, NLR3/4, and Hsp70 involved in the immune response pathways to phagocytosed particles were evaluated with the usage of the Western blot analysis. mRNA encoding the iNOS protein was detected by reverse transcription PCR method. The most meaningful changes were observed for PLA2 and NLC4 proteins level and between iNOS protein expression and mRNA encoding iNOS protein amount. The EMF exposure exerted the strongest effect on iNOS encoding mRNA in cells pre-stimulated with LPS or SEB and phagocytosing LBs. The influence of EMF on phagocytosis was experimentally proved for the first time and there is a need for further investigations in term of the usage of EMF as a prospect, supportive therapy.

The critical role of superoxide anion radicals on delaying tetrachlorohydroquinone autooxidation by penicillamine

We have recently found that penicillamine, a classic copper-chelating thiol-drug for Wilson's disease, can delay tetrachlorohydroquinone (TCHQ) autooxidation via a previously unrecognized redox-activity. However, its underlying molecular mechanism remains not fully understood. In this study, we found, interestingly and unexpectedly, that superoxide dismutase (SOD) can significantly shorten the delay of TCHQ autooxidation by penicillamine, but not by ascorbate; SOD can also markedly increase the yields of the oxidized form of penicillamine. Similar effects were observed with a recently-developed specific and sensitive superoxide anion radical (O₂^•-) probe CT-02H, which was also employed to successfully measure O₂^•- generated from both TCHQ and TCHQ/penicillamine systems for the first time. More importantly, addition of extra O₂^•- (KO₂/18-crown-6) can further prolong the delaying effects by penicillamine and slow down penicillamine consumption. Taken together, an unexpected critical role of O₂^•- in TCHQ/penicillamine interaction was proposed: O₂^•- may regenerate penicillamine, thereby continuously reducing TCSQ^•- to TCHQ and finally delaying TCHQ autooxidation; In contrast, if O₂^•- were eliminated, which can not only markedly change the reaction equilibrium, accelerate the rate of interaction, and ultimately shorten the delay of TCHQ autooxidation by penicillamine, but can also accelerate penicillamine oxidation to form its corresponding disulfide solely via redox reaction without any minor nucleophilic reaction. These findings not only further support our previously-proposed redox mechanism for the protection against TCHQ-induced cytotoxicity by penicillamine, but also reveal a new mode of action for O₂^•- in the inhibition of haloquinoids-induced toxicity by thiol antioxidants.

The Promising Role of Antioxidant Phytochemicals in the Prevention and Treatment of Periodontal Disease via the Inhibition of Oxidative Stress Pathways: Updated Insights

There is growing evidence on the involvement of oxidative stress, which is simply described as the imbalance between oxidants and antioxidants in favor of the former, in the development of periodontal disease that is the most common inflammatory disease in the oral cavity. Thus, the potential of antioxidant phytochemicals as adjunctively preventive and therapeutic agents against the initiation and progression of periodontal disease is a topic of great interest. The current review firstly aims to provide updated insights about the immuno-inflammatory pathway regulated by oxidative stress in periodontal pathology. Then, this work further presents the systemic knowledge of antioxidant phytochemicals, particularly the pharmacological activities, which can be utilized in the prevention and treatment of periodontal disease. Additionally, the challenges and future prospects regarding such a scope are figured out.

High intensity interval training protects from Post Traumatic Stress Disorder induced cognitive impairment

This study aimed to show the possible protective effects of high intensity interval training (HIIT) in PTSD-induced rats and probable underlying mechanisms. Female rats (n = 44) were separated as; Sedentary (SED), moderate intensity continuous training (MICT), HIIT groups. Then the groups were divided into subgroups according to PTSD induction (n = 6-8/group). Exercise groups performed HIIT or MICT for 6 weeks. On the fifth week, PTSD was induced by single prolonged stress protocol. Cognitive functions were evaluated by object recognition, anxiety levels by hole-board and elevated plus maze, and fear conditioning by passive avoidance tests. Following decapitation, malondialdehyde (MDA), glutathione (GSH), luminol and lucigenin chemiluminescence levels, and myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) activities were measured, and histopathological damage was evaluated. The data was analyzed by one-way ANOVA. Cognitive decline and aggravated anxiety levels in SED + PTSD group were improved in both PTSD-induced exercise groups (p < 0.05-0.001). The increased chemiluminescence levels, MPO activity and histological damage were depressed in both PTSD-induced exercise groups (p < 0.05-0.001). The risen MDA levels in SED + PTSD group were suppressed only in HIIT + PTSD group (p < 0.01-0.001). The decreased GSH levels were increased by MICT (p < 0.05-0.001), and CAT and SOD activities were improved via HIIT (p < 0.05). Compared to SED group, latency was decreased in SED + PTSD (p < 0.05-0.01) group. Neuronal damage scores were alleviated in both PTSD-induced exercise groups (p < 0.001). PTSD-induced memory decline was protected by both of the exercise models however more effectively by HIIT via decreasing oxidative stress, anxiety levels and by improving antioxidant capacity as a protective system for neuronal damage.

The Redox Balance: A Target for Interventions Against Muscle Wasting in Cancer Cachexia?

Significance: The management of cancer patients is frequently complicated by the occurrence of a complex syndrome known as cachexia. It is mainly characterized by muscle wasting, a condition that associates with enhanced protein breakdown and with negative energy balance. While the mechanisms underlying cachexia have been only partially elucidated, understanding the pathogenesis of muscle wasting in cancer hosts is mandatory to design new targeted therapeutic strategies. Indeed, most of cancer patients will experience cachexia during the course of their disease, and about 25% of cancer-related deaths are due to this syndrome, rather than to the tumor itself. Recent Advances: Compelling evidence suggests that an altered redox homeostasis likely contributes to cancer-induced muscle protein depletion, directly or indirectly activating the intracellular degradative pathways. In addition, oxidative stress impinges on both mitochondrial number and function; the other way round, altered mitochondria lead to enhanced redox imbalance, creating a vicious loop that eventually results in negative energy metabolism. Critical Issues: The present review focuses on the possibility that pharmacological and nonpharmacological strategies able to restore a physiologic redox balance could be useful components of treatment schedules aimed at counteracting cancer-induced muscle wasting. Future Directions: Exercise and the use of exercise mimetic drugs represent the most promising approaches capable of reinforcing the muscle antioxidant defenses of cancer patients. The results from ongoing and new clinical trials are needed to validate the preclinical studies and provide effective therapies for cancer cachexia. Antioxid. Redox Signal. 33, 542-558.

Therapeutic strategies for ischemia reperfusion injury in emergency medicine

Ischemia reperfusion (IR) injury occurs when blood supply, perfusion, and concomitant reoxygenation is restored to an organ or area following an initial poor blood supply after a critical time period. Ischemia reperfusion injury contributes to mortality and morbidity in many pathological conditions in emergency medicine clinical practice, including trauma, ischemic stroke, myocardial infarction, and post‐cardiac arrest syndrome. The process of IR is multifactorial, and its pathogenesis involves several mechanisms. Reactive oxygen species are considered key molecules in reperfusion injury due to their potent oxidizing and reducing effects that directly damage cellular membranes by lipid peroxidation. In general, IR injury to an individual organ causes various pro‐inflammatory mediators to be released, which could then induce inflammation in remote organs, thereby possibly advancing the dysfunction of multiple organs. In this review, we summarize IR injury in emergency medicine. Potential therapies include pharmacological treatment, ischemic preconditioning, and the use of medical gases or vitamin therapy, which could significantly help experts develop strategies to inhibit IR injury.

Nucleotides released from palmitate-activated murine macrophages attract neutrophils

Obesity and elevation of circulating free fatty acids are associated with an accumulation and proinflammatory polarization of macrophages within metabolically active tissues, such as adipose tissue, muscle, liver, and pancreas. Beyond macrophages, neutrophils also accumulate in adipose and muscle tissues during high-fat diets and contribute to a state of local inflammation and insulin resistance. However, the mechanisms by which neutrophils are recruited to these tissues are largely unknown. Here we used a cell culture system as proof of concept to show that, upon exposure to a saturated fatty acid, palmitate, macrophages release nucleotides that attract neutrophils. Moreover, we found that palmitate up-regulates pannexin-1 channels in macrophages that mediate the attraction of neutrophils, shown previously to allow transfer of nucleotides across membranes. These findings suggest that proinflammatory macrophages release nucleotides through pannexin-1, a process that may facilitate neutrophil recruitment into metabolic tissues during obesity.

Bilirubin Links Heme Metabolism to Neuroprotection by Scavenging Superoxide

Bilirubin is one of the most frequently measured metabolites in medicine, yet its physiologic roles remain unclear. Bilirubin can act as an antioxidant in vitro, but whether its redox activity is physiologically relevant is unclear because many other antioxidants are far more abundant in vivo. Here, we report that depleting endogenous bilirubin renders mice hypersensitive to oxidative stress. We find that mice lacking bilirubin are particularly vulnerable to superoxide (O₂^⋅-) over other tested reactive oxidants and electrophiles. Whereas major antioxidants such as glutathione and cysteine exhibit little to no reactivity toward O₂^⋅-, bilirubin readily scavenges O₂^⋅-. We find that bilirubin's redox activity is particularly important in the brain, where it prevents excitotoxicity and neuronal death by scavenging O₂^⋅- during NMDA neurotransmission. Bilirubin's unique redox activity toward O₂^⋅- may underlie a prominent physiologic role despite being significantly less abundant than other endogenous and exogenous antioxidants.

The Potential Health Benefits of Noni Juice: A Review of Human Intervention Studies

Noni juice is a globally popular health beverage originating in the tropics. Traditional Tahitian healers believe the noni plant to be useful for a wide range of maladies, and noni juice consumers throughout the world have similar perceptions. Nevertheless, human clinical trials are necessary for a precise understanding of what the health benefits of noni juice are. A review of published human intervention studies suggests that noni juice may provide protection against tobacco smoke-induced DNA damage, blood lipid and homocysteine elevation as well as systemic inflammation. Human intervention studies also indicate that noni juice may improve joint health, increase physical endurance, increase immune activity, inhibit glycation of proteins, aid weight management, help maintain bone health in women, help maintain normal blood pressure, and improve gum health. Further, these studies point to notable antioxidant activity in noni juice, more so than other fruit juices which served as trial placebos. It is this antioxidant effect and its interaction with the immune system and inflammation pathways that may account for many of the observed health benefits of noni juice. However, the existing evidence does have some limitations as far as its general application to noni juice products; all the peer-reviewed human interventions studies to date have involved only one source of French Polynesian noni juice. Geographical factors and variations in processing methods are known to produce commercial noni juice products with divergent phytochemical and nutrient compositions. Therefore, other sources of noni products may have different toxicological and pharmacological profiles.

Superoxide dismutase from Helicobacter pylori suppresses the production of pro-inflammatory cytokines during in vivo infection

BACKGROUND

Helicobacter pylori has undergone considerable adaptation to allow chronic persistence within the gastric environment. While H. pylori-associated diseases are driven by an excessive inflammation, severe gastritis is detrimental to colonization by this pathogen. Hence, H. pylori has developed strategies to minimize the severity of gastritis it triggers in its host. Superoxide dismutase (SOD) is well known for its role in protecting against oxidative attack; less recognized is its ability to inhibit immunity, shown for SOD from mammalian sources and those of some bacterial species. This study examined whether H. pylori SOD (HpSOD) has the ability to inhibit the host immune response to these bacteria.

MATERIALS AND METHODS

The ability of recombinant HpSOD to modify the response to LPS was measured using mouse macrophages. A monoclonal antibody against HpSOD was generated and injected into H. pylori-infected mice.

RESULTS

Addition of HpSOD to cultures of mouse macrophages significantly inhibited the pro-inflammatory cytokine response to LPS stimulation. A monoclonal antibody was generated that was specific for SOD from H. pylori. When injected into mice infected with H. pylori for 3 months, this antibody was readily detected in both sera and gastric tissues 5 days later. While treatment with anti-HpSOD had no effect on H. pylori colonization at this time point, it significantly increased the levels of a range of pro-inflammatory cytokines in the gastric tissues. This did not occur with antibodies against other antioxidant enzymes.

CONCLUSIONS

SOD from H. pylori can inhibit the production of pro-inflammatory cytokine during in vivo infection.

A Mini-Review on the Effect of Docosahexaenoic Acid (DHA) on Cerulein-Induced and Hypertriglyceridemic Acute Pancreatitis

Acute pancreatitis refers to the sudden inflammation of the pancreas. It is associated with premature activation and release of digestive enzymes into the pancreatic interstitium and systemic circulation, resulting in pancreatic tissue autodigestion and multiple organ dysfunction, as well as with increased cytokine production, ultimately leading to deleterious local and systemic effects. Although mechanisms involved in pathogenesis of acute pancreatitis have not been completely elucidated, oxidative stress is regarded as a major risk factor. In human acute pancreatitis, lipid peroxide levels in pancreatic tissues increase. Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (C22:6n-3), exerts anti-inflammatory and antioxidant effects on various cells. Previous studies have shown that DHA activates peroxisome proliferator-activated receptor-γ and induces catalase, which inhibits oxidative stress-mediated inflammatory signaling required for cytokine expression in experimental acute pancreatitis using cerulein. Cerulein, a cholecystokinin analog, induces intra-acinar activation of trypsinogen in the pancreas, which results in human acute pancreatitis-like symptoms. Therefore, DHA supplementation may be beneficial for preventing or inhibiting acute pancreatitis development. Since DHA reduces serum triglyceride levels, addition of DHA to lipid-lowering drugs like statins has been investigated to reduce hypertriglyceridemic acute pancreatitis. However, high DHA concentrations increase cytosolic Ca²⁺, which activates protein kinase C and may induce hyperlipidemic acute pancreatitis. In this review, effect of DHA on cerulein-induced and hypertriglyceridemic acute pancreatitis has been discussed. The relation of high concentration of DHA to hyperlipidemic acute pancreatitis has been included.

Role of Redox Signaling and Inflammation in Skeletal Muscle Adaptations to Training

The inflammatory response to exercise-induced muscle damage has been extensively described. Exercise has important modulatory effects on immune function. These effects are mediated by diverse factors including pro-inflammatory cytokines, classical stress hormones, and hemodynamic effects leading to cell redistribution. As has been reported regarding oxidative stress, inflammation can have both detrimental and beneficial effects in skeletal muscle. In this review we will address the role of inflammation on protein metabolism in skeletal muscle. Specifically, we will review studies showing that treatment with cyclooxygenase-inhibiting drugs modulate the protein synthesis response to one bout of resistance exercise and to training. Understanding how these drugs work is important for the millions of individuals worldwide that consume them regularly. We will also discuss the importance of reactive oxygen species and inflammatory cytokines in muscle adaptations to exercise and the Janus faced of the use of antioxidant and anti-inflammatory drugs by athletes for optimizing their performance, especially during the periods in which muscle hypertrophy is expected.

[Tourniquet-induced ischaemia-reperfusion injury: the comparison of antioxidative effects of small-dose propofol and ketamine]

OBJECTIVES

The aim of the present study was to investigate the preventive effects of propofol and ketamine as small dose sedation during spinal anesthesia on tourniquet-induced ischemia-reperfusion injury.

METHODS

30 patients were randomly assigned into two groups of 15 patients. In the propofol group, sedation was performed with propofol 0.2mg.kg^-1 followed by infusion at a rate of 2mg.kg^-1.h^-1. In the ketamine group, a continuous infusion of ketamine 0.5mg.kg^-1.h^-1 was used until the end of surgery. Intravenous administration of midazolam was not used in any patients. Ramsay sedation scale was used for assessing the sedation level. Venous blood samples were obtained before propofol and ketamine infusion (T1), at 30minutes (min) of tourniquet ischemia (T2), and 5min after tourniquet deflation (T3) for malondialdehyde (MDA) measurements.

RESULTS

No differences were noted between the groups in hemodynamic (p>0.05) and demographic data (p>0.05). There was no statistically significant difference between the two groups in terms of T1, T2 and T3 periods (p>0.05). There was a statistically increase observed in MDA values respectively both in Group P and Group K between the reperfusion period (1.95±0.59, 2.31±0.48) and pre-ischemia (1.41±0.38, 1.54±0.45), and ischemia (1.76±0.70, 1.71±0.38) (μmoL^-1) periods (p<0.05).

CONCLUSIONS

Small-dose propofol and ketamine has similar potential to reduce the oxidative stress caused by tourniquet-induced ischemia-reperfusion injury in patients undergoing arthroscopic knee surgery under spinal anesthesia.

Rational Design and Synthesis of New, High Efficiency, Multipotent Schiff Base-1,2,4-triazole Antioxidants Bearing Butylated Hydroxytoluene Moieties

A new series of multipotent antioxidants (MPAOs), namely Schiff base-1,2,4-triazoles attached to the oxygen-derived free radical scavenging moiety butylated hydroxytoluene (BHT) were designed and subsequently synthesized. The structure-activity relationship (SAR) of the designed antioxidants was established alongside the prediction of activity spectra for substances (PASS). The antioxidant activities of the synthesized compounds 4-10 were tested by the DPPH bioassay. The synthesized compounds 4-10 inhibited stable DPPH free radicals at a level that is 10(-4) M more than the well-known standard antioxidant BHT. Compounds 8-10 with para-substituents were less active than compounds 4 and 5 with trimethoxy substituents compared to those with a second BHT moiety (compounds 6 and 7). With an IC50 of 46.13 ± 0.31 µM, compound 6 exhibited the most promising in vitro inhibition at 89%. Therefore, novel MPAOs containing active triazole rings, thioethers, Schiff bases, and BHT moieties are suggested as potential antioxidants for inhibiting oxidative stress processes and scavenging free radicals, hence, this combination of functions is anticipated to play a vital role in repairing cellular damage, preventing various human diseases and in medical therapeutic applications.

The rat closely mimics oxidative stress and inflammation in humans after exercise but not after exercise combined with vitamin C administration

PURPOSE

The purpose of the present study was to directly compare oxidative stress and inflammation responses between rats and humans.

METHODS

We contrasted rat and human oxidative stress and inflammatory responses to exercise (pro-oxidant stimulus) and/or vitamin C (anti-oxidant stimulus) administration. Vitamin C was administered orally in both species (16 mg kg(-1) of body weight). Twelve redox biomarkers and seven inflammatory biomarkers were determined in plasma and erythrocytes pre- and post-exercise or pre- and post-exercise combined with vitamin C administration.

RESULTS

Exercise increased oxidative stress and induced an inflammatory state in rats and humans. There were only 1/19 significant species × exercise interactions (catalase), indicating similar responses to exercise between rats and humans in redox and inflammatory biomarkers. Vitamin C decreased oxidative stress and increased antioxidant capacity only in humans and did not affect the redox state of rats. In contrast, vitamin C induced an anti-inflammatory state only in rats and did not affect the inflammatory state of humans. There were 10/19 significant species × vitamin C interactions, indicating that rats poorly mimic human oxidative stress and inflammatory responses to vitamin C administration. Exercise after acute vitamin C administration altered redox state only in humans and did not affect the redox state of rats. On the contrary, inflammation biomarkers changed similarly after exercise combined with vitamin C in both rats and humans.

CONCLUSIONS

The rat adequately mimics human responses to exercise in basic blood redox/inflammatory profile, yet this is not the case after exercise combined with vitamin C administration.

Xanthine Oxidoreductase-Derived Reactive Species: Physiological and Pathological Effects

Xanthine oxidoreductase (XOR) is the enzyme that catalyzes the oxidation of hypoxanthine to xanthine and xanthine to uric acid and is widely distributed among species. In addition to this housekeeping function, mammalian XOR is a physiological source of superoxide ion, hydrogen peroxide, and nitric oxide, which can function as second messengers in the activation of various pathways. This review intends to address the physiological and pathological roles of XOR-derived oxidant molecules. The cytocidal action of XOR products has been claimed in relation to tissue damage, in particular damage induced by hypoxia and ischemia. Attempts to exploit this activity to eliminate unwanted cells via the construction of conjugates have also been reported. Moreover, different aspects of XOR activity related to phlogosis, endothelial activation, leukocyte activation, and vascular tone regulation, have been taken into consideration. Finally, the positive and negative outcomes concerning cancer pathology have been analyzed because XOR products may induce mutagenesis, cell proliferation, and tumor progression, but they are also associated with apoptosis and cell differentiation. In conclusion, XOR activity generates free radicals and other oxidant reactive species that may result in either harmful or beneficial outcomes.

Preservation of renal blood flow by the antioxidant EUK-134 in LPS-treated pigs

Sepsis is associated with an increase in reactive oxygen species (ROS), however, the precise role of ROS in the septic process remains unknown. We hypothesized that treatment with EUK-134 (manganese-3-methoxy N,N'-bis(salicyclidene)ethylene-diamine chloride), a compound with superoxide dismutase and catalase activity, attenuates the vascular manifestations of sepsis in vivo. Pigs were instrumented to measure cardiac output and blood flow in renal, superior mesenteric and femoral arteries, and portal vein. Animals were treated with saline (control), lipopolysaccharide (LPS; 10 µg·kg-1·h-1), EUK-134, or EUK-134 plus LPS. Results show that an LPS-induced increase in pulmonary artery pressure (PAP) as well as a trend towards lower blood pressure (BP) were both attenuated by EUK-134. Renal blood flow decreased with LPS whereas superior mesenteric, portal and femoral flows did not change. Importantly, EUK-134 decreased the LPS-induced fall in renal blood flow and this was associated with a corresponding decrease in LPS-induced protein nitrotyrosinylation in the kidney. PO2, pH, base excess and systemic vascular resistance fell with LPS and were unaltered by EUK-134. EUK-134 also had no effect on LPS-associated increase in CO. Interestingly, EUK-134 alone resulted in higher CO, BP, PAP, mean circulatory filling pressure, and portal flow than controls. Taken together, these data support a protective role for EUK-134 in the renal circulation in sepsis.

Reactive oxygen and nitrogen species: impact on endothelial dysfunction

BACKGROUND

Reactive oxygen and nitrogen species, known as free radicals, play a key role in the etiology and progression of atherosclerotic cardiovascular disease by creating vascular oxidative stress.

PURPOSE

This review will discuss current biological research about the enzymatic and nonenzymatic sources of oxidative stress, free radical chemistry, and how it pertains to endothelial dysfunction-a hallmark of cardiovascular disease.

METHODS

An integrative review of the literature was conducted.

FINDINGS

Free radicals lower the bioavailability of the potent vasodilator nitric oxide and therefore, through numerous chemical reactions, negatively affect vascular biology and endothelial function. Endothelial dysfunction is considered to be integral in the initiation of atherosclerosis.

CONCLUSIONS

The success and failures of current therapies to reduce oxidative stress are discussed in terms of implications for nursing research on exogenous antioxidants, pharmacotherapy, and lifestyle change.

P8 deficiency increases cellular ROS and induces HO-1

The gene p8 encodes for a small cytoprotective protein with no apparent enzymatic activity being proposed to act as co-transcription factor whose expression is increased during inflammation. Recent data from astrocytes demonstrates that p8 suppression leads to induction of heme oxygenase 1 (HO-1). Here, we assessed the cross-talk between p8 and HO-1 in mouse embryonic fibroblasts (MEF) observing an increased expression of HO-1 in p8-deficient (p8(-/-)) MEFs in non-treated and treated conditions. This effect was independent of the cell cycle. Our findings revealed that generation of reactive oxygen species (ROS) was higher in p8(-/-) MEFs. Mitochondria and NADPH oxidases were not the origin of ROS. This observation was not restricted to MEF as suppression of p8 gene transcription in MiaPaCa-2 cells also led to increased intracellular ROS. Additionally, p8 deficiency did not affect the Rac1 dependant NADPH oxidase complex. Our data shows that p8 deficiency increases ROS and subsequently the expression of anti-oxidative enzymes, such as HO-1, suggesting an involvement in the anti-oxidative defense. Moreover, we suggest that the severity of AP observed in p8(-/-) mice is induced by an impaired anti oxidative capacity of the pancreas, which is caused by increased generation of ROS.

Redox pioneer: Professor Joe M. McCord

Dr. Joe McCord (Ph.D. 1970) is recognized here as a Redox Pioneer because he has published at least three articles on antioxidant/redox biology as first/last author that have been cited over 1000 times and has published at least 37 articles each cited over 100 times. Dr. McCord is known for the monumental discovery of the antioxidant superoxide dismutase (SOD) while a graduate student under fellow redox pioneer Irwin Fridovich and demonstrating its necessity to aerobic life. Beyond this, McCord's career is distinguished for bridging the gap from basic science to clinical relevance by showing the application of SOD and superoxide to human physiology, and characterizing the physiological functions of superoxide in inflammation, immunological chemotaxis, and ischemia-reperfusion injury, among other disease conditions. Work by McCord serves as the foundation upon which our understanding of how superoxide functions in a variety of physiological systems is built and demonstrates how superoxide is essential to aerobic life, yet, if left unchecked by SOD, toxic to a multitude of systems. These discoveries have substantial significance in a wide range of studies with applications in cardiovascular disease, cancer, neurology, and medicine, as well as general health and longevity. Dr. McCord's contributions to free radical biology have been recognized through many prestigious achievement awards, honorary titles, and conferences around the world; each serving as a testament to his status as a redox pioneer.

Studies on the Antimicrobial and Antioxidant Activity and Chemical Composition of the Essential Oils of Kitaibelia vitifolia

The objective of this study was to evaluate the potential use of the essential oil of Kitaibelia vitifolia Willd. in the pharmaceutical and food industries. Antimicrobial and antioxidant activities of essential oil of K. vitifolia isolated by hydrodistillation using a Clevenger-type apparatus were assessed. GC/FID and GC/MS analyses were used to determine the major components of the essential oil as sclareoloxide ( cis A/B) 17.9%, sclaral 10.9%, labda-7,13,14-triene 10.6% and sclareol 9.5%. The antimicrobial activity of the essential oil was evaluated against the bacterial strains: Staphylococcus aureus ATCC 25923, Klebsiella pneumoniae ATCC 13883, Escherichia coli ATCC 25922, Proteus vulgaris ATCC 13315, P. mirabilis ATCC 14153, and Bacillus subtilis ATCC 6633; and fungal strains: Candida albicans ATCC 10231 and Aspergillus niger ATCC 16404. Antimicrobial activity was tested using a broth dilution procedure for determination of minimum inhibitory concentration (MIC). The essential oil of K. vitifolia showed strong antimicrobial activity. Antioxidant activities of the essential oils were evaluated using the DPPH and hydroxy radical scavenging, lipid peroxidation and metal chelating assays. The results for antioxidant activity were compared with control antioxidants, ascorbic acid, gallic acid, α-tocopherol and BHT. Results showed that the essential oil possesses antioxidant activity, with total antioxidant capacity of 95.4±0.7 μg AA/g and IC50 values of 5.45±1.45 μg/mL for DPPH free radical scavenging activity, 26.5±1.6 μg/mL for inhibitory activity against lipid peroxidation, 79.4±0.4 μg/mL for hydroxyl radical scavenging activity, and 39.9±0.7 μg/mL for metal chelating activity.

Stimulatory effects of chitinase on growth and immune defense of orange-spotted grouper (Epinephelus coioides)

Chitinase, belonging to either family 18 or family 19 of the glycosylhydrolases, hydrolyze chitin into oligosaccharides. In the present study, the cDNA fragment encoding orange-spotted grouper (Epinephelus coioides) chitinase1 was subcloned into pPIC3.5K vector and expressed in Pichia pastoris GS115. The results showed that a band with the size of about 53 kDa could be detected by SDS-PAGE and Western blot. The recombinant protein of grouper chitinase1 (rgChi1) was added into the fish diet containing shrimp shell chitin for feeding experiment lasting 8 weeks. The weight of orange-spotted grouper, fed with diets containing rgChi1 at 0, 5, 10 and 20 μg/g was calculated on the 2nd, 4th, 6th and 8th weeks, and difference in growth rates was first observed in the 6th week of the feeding period and it kept until the end of the feeding experiment. At the end of 8 weeks feeding trial, the percent weight gain (PWG), growth rate (GR) and specific growth rate (SGR) of fish fed with 10 and 20 μg rgChi1/g feed were significantly higher compared to the control group. The neuropeptide Y (NPY), growth-hormone-releasing hormone (GHRH), growth-hormone (GH), interleukin-1beta (IL-1β), cyclooxygenase-2 (COX-2), superoxide dismutase (SOD) (Cu/Zn) and SOD (Mn) mRNA expression of fish fed with diet containing 10 μg/g or/and 20 μg/g rgChi1 were obviously higher than the control group. The lysozyme (LZM) and total SOD activity of fish fed with diet containing rgChi1 at 10 and 20 μg/g were significantly higher than that of the control. The aspartate aminotransferase (AST)/glutamic oxalacetic transaminases (GOT) activity in 20 μg/g group decreased compared to the control group. These results indicated that the grouper chitinase1 was successfully produced using the P. pastoris expression system and the recombinant protein had obvious effects on growth and immune defense. The mRNA expression and protein secretion of grouper chitinase1 and chitinase2 were significantly stimulated in spleen in response to bacterial lipopolysaccharide (LPS) challenge, strongly suggesting the existence of an innate pathway for local defense against chitin-containing organisms. Moreover, the pathogen such as Escherichia coli and Staphylococcus aureus could be inhibited by the recombinant protein of grouper chitinase1 to a certain extent.

Short courses of mechanical ventilation with high-O2 levels in elderly rat lungs

PURPOSE

To evaluate the effects of mechanical ventilation (MV) of high-oxygen concentration in pulmonary dysfunction in adult and elderly rats.

METHODS

Twenty-eight adult (A) and elderly (E), male rats were ventilated for 1 hour (G-AV1 and G-EV1) or for 3 hours (G-AV3 and G-EV3). A and E groups received a tidal volume of 7 mL/kg, a positive end-expiratory pressure of 5 cm H2O, respiratory rate of 70 cycles per minute, and an inspiratory fraction of oxygen of 1. We evaluated total protein content and malondialdehyde in bronchoalveolar lavages (BAL) and performed lung histomorphometrical analyses.

RESULTS

In G-EV1 animals, total protein in BAL was higher (33.0±1.9 µg/mL) compared with G-AV1 (23.0±2.0 µg/mL). Upon 180 minutes of MV, malondialdehyde levels increased in elderly (G-EV3) compared with adult (G-AV3) groups. Malondialdehyde and total proteins in BAL after 3 hours of MV were higher in elderly group than in adults. In G-EV3 group we observed alveolar septa dilatation and significative increase in neutrofiles number in relation to adult group at 60 and 180 minutes on MV.

CONCLUSION

A higher fraction of inspired oxygen in short courses of mechanical ventilation ameliorates the parameters studied in elderly lungs.

Effect of Shenmai injection, a traditional Chinese medicine, on pulmonary dysfunction after tourniquet-induced limb ischemia-reperfusion

BACKGROUND

Tourniquet has been considered as a recognized cause of lower limb ischemia-reperfusion injury in the orthopedic field. This study investigates pulmonary function after tourniquet deflation and the protective effect of Shenmai injection (SMI), a traditional Chinese medicine.

METHODS

Twenty-eight patients undergoing lower extremity surgery were randomized into a control group (group C) and a SMI group (group S), 14 patients in each group. Blood gas and circulating indicators (malondialdehyde, interleukin [IL]-6, and IL-8) were measured immediately before tourniquet inflation and at 0.5 hour, 2 hours, 6 hours, and 24 hours after tourniquet deflation.

RESULTS

Plasma levels of malondialdehyde, IL-6, and IL-8 in group C were significantly increased over baselines from 2 hours to 24 hours after tourniquet deflation and the levels reached their peaks at 6 hours after tourniquet deflation, when arterial partial pressures of oxygen and arterial-alveolar oxygen tension ratio were decreased, whereas alveolar-arterial oxygen difference was increased significantly. Both the changes in blood gas variables and plasma mediators were attenuated in group S.

CONCLUSION

Pulmonary gas exchange is impaired after lower limb ischemia-reperfusion induced by clinical tourniquet application. Pretreatment with SMI, a traditional Chinese medicine, attenuates lipid peroxidation and systemic inflammatory response and mitigates pulmonary dysfunction.

Oxidative stress in health and disease: the therapeutic potential of Nrf2 activation

For the past 40 years or so, oxidative stress has been increasingly recognized as a contributing factor in aging and in various forms of pathophysiology generally associated with aging. Our view of oxidative stress has been largely "superoxide-centric", as we focused on the pathological sources of this oxygen-derived free radical and the types of molecular havoc it can wreak, as well as on the protection provided by the antioxidant enzymes, especially the superoxide dismutases, catalases, and glutathione peroxidases. In the last decade our view of oxidative stress has broadened considerably, and it is now often seen as an imbalance that has its origins in our genes, and the ways in which gene expression is regulated. At the center of this new focus is the transcription factor called nuclear factor (erythroid-derived 2)-like 2, or Nrf2. Nrf2 is referred to as the "master regulator" of the antioxidant response, modulating the expression of hundreds of genes, including not only the familiar antioxidant enzymes, but large numbers of genes that control seemingly disparate processes such as immune and inflammatory responses, tissue remodeling and fibrosis, carcinogenesis and metastasis, and even cognitive dysfunction and addictive behavior. Thus, the dysregulation of Nrf2-regulated genes provides a logical explanation for the connections, both direct and indirect, between observable oxidative stress and perhaps 200 human diseases involving these various physiological processes, each reflecting a network involving many gene products. The evolutionary self-association of these many genes under the common control of Nrf2 suggests that the immune and inflammatory systems may present the largest demand for increased antioxidant protection, apart from constitutive oxidative stress resulting from mitochondrial oxygen consumption for metabolic purposes. Gene expression microarray data on human primary vascular endothelial cells and on the SK-N-MC human neuroblastoma-derived cell line have been obtained in response to the dietary supplement Protandim, a potent composition of highly synergistic phytochemical Nrf2 activators. Pathway analysis of results shows significant modulation by Protandim of pathways involving not only antioxidant enzymes, but of those related to colon cancer, cardiovascular disease, and Alzheimer disease.

Oxidative stress and redox modulation potential in type 1 diabetes

Redox reactions are imperative to preserving cellular metabolism yet must be strictly regulated. Imbalances between reactive oxygen species (ROS) and antioxidants can initiate oxidative stress, which without proper resolve, can manifest into disease. In type 1 diabetes (T1D), T-cell-mediated autoimmune destruction of pancreatic β-cells is secondary to the primary invasion of macrophages and dendritic cells (DCs) into the islets. Macrophages/DCs, however, are activated by intercellular ROS from resident pancreatic phagocytes and intracellular ROS formed after receptor-ligand interactions via redox-dependent transcription factors such as NF-κB. Activated macrophages/DCs ferry β-cell antigens specifically to pancreatic lymph nodes, where they trigger reactive T cells through synapse formation and secretion of proinflammatory cytokines and more ROS. ROS generation, therefore, is pivotal in formulating both innate and adaptive immune responses accountable for islet cell autoimmunity. The importance of ROS/oxidative stress as well as potential for redox modulation in the context of T1D will be discussed.

Potential role of NADPH oxidase-mediated activation of Jak2/Stat3 and mitogen-activated protein kinases and expression of TGF-β1 in the pathophysiology of acute pancreatitis

OBJECTIVE

NADPH oxidase is potentially associated with acute pancreatitis by producing reactive oxygen species (ROS). We investigated whether NADPH oxidase mediates the activation of Janus kinase (Jak)2/signal transducers and activators of transcription (Stat)3 and mitogen-activated protein kinases (MAPKs) to induce the expression of transforming growth factor-β1 (TGF-β1) in cerulein-stimulated pancreatic acinar cells.

TREATMENT

AR42J cells were treated with an NADPH oxidase inhibitor diphenyleneiodonium (DPI) or a Jak2 inhibitor AG490. Other cells were transfected with antisense or sense oligonucleotides (AS or S ODNs) for NADPH oxidase subunit p22(phox) or p47(phox).

METHODS

TGF-β1 was determined by enzyme-linked immonosorbent assay. STAT3-DNA binding activity was measured by electrophoretic mobility shift assay. Levels of MAPKs as well as total and phospho-specific forms of Jak1/Stat3 were assessed by Western blot analysis.

RESULTS

Cerulein induced increases in TGF-β1, Stat3-DNA binding activity and the activation of MAPKs in AR42J cells. AG490 suppressed these cerulein-induced changes, similar to inhibition by DPI. Cerulein-induced activation of Jak2/Stat3 and increases in MAPKs and TGF-β1 levels were inhibited in the cells transfected with AS ODN for p22(phox) and p47(phox) compared to S ODN controls.

CONCLUSION

Inhibition of NADPH oxidase may be beneficial for prevention and treatment of pancreatitis by suppressing Jak2/Stat3 and MAPKs and expression of TGF-β1 in pancreatic acinar cells.

The role of liver biopsy in detection of hepatic oxidative stress

The goal of the current paper is to explore the role of liver biopsy as a tool in detection of hepatic oxidative stress, with brief notes on different types of free radicals, antioxidants, hepatic and blood oxidative stress, and lipid peroxidation. Hepatic oxidative stress was investigated for many years in human and animals, but most of the studies performed in animals were concerned with studying oxidative status in the liver tissues after slaughtering or euthanasia. However, in human medicine, a large number of studies were implemented to investigate the status of antioxidants in liver biopsy specimens. Similar studies are required in animals, as the changes in hepatic antioxidants and formation of lipid peroxide give a good idea about the condition of the liver. On the other hand, hepatic disease may present without significant effect on blood oxidative status, and, consequently, the best way to detect the status of hepatic oxidants and antioxidants is through measuring in liver biopsy. Measuring antioxidants status directly in the liver tissues gives an accurate estimation about the condition of the liver, permits the diagnosis of hepatic dysfunction, and helps to determine the degree of deterioration in the hepatic cells.

Effect of Extremely Low Frequency Electromagnetic Fields (EMF) on Phospholipase Activity in the Cultured Cells

This study was conducted to investigate the effects of extremely low frequency electromagnetic fields (EMF) on signal pathway in plasma membrane of cultured cells (RAW 264.7 cells and RBL 2H3 cells), by measuring the activity of phospholipase A(2) (PLA(2)), phospholipase C (PLC) and phospholipase D (PLD). The cells were exposed to the EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h. The basal and 0.5 µM melittin-induced arachidonic acid release was not affected by EMF in both cells. In cell-free PLA(2) assay, we failed to observe the change of cPLA(2) and sPLA(2) activity. Also both PLC and PLD activities did not show any change in the two cell lines exposed to EMF. This study suggests that the exposure condition of EMF (60 Hz, 0.1 or 1 mT) which is 2.4 fold higher than the limit of occupational exposure does not induce phospholipases-associated signal pathway in RAW 264.7 cells and RBL 2H3 cells.

Fast reactivity of a cyclic nitrone-calix[4]pyrrole conjugate with superoxide radical anion: theoretical and experimental studies

Nitrone spin traps have been employed as probes for the identification of transient radical species in chemical and biological systems using electron paramagnetic resonance (EPR) spectroscopy and have exhibited pharmacological activity against oxidative-stress-mediated diseases. Since superoxide radical anion (O2(•-)) is a major precursor to most reactive oxygen species and calix[4]pyrroles have been shown to exhibit high affinity to anions, a cyclic nitrone conjugate of calix[4]pyrrole (CalixMPO) was designed, synthesized, and characterized. Computational studies at the PCM/B3LYP/6-31+G(d,p)//B3LYP/6-31G(d) level suggest a pendant-type linkage between the calix[4]pyrrole and the nitrone to be the most efficient design for spin trapping of O2(•-), giving exoergic reaction enthalpies (ΔH(298K,aq)) and free energies (ΔG(298K,aq)) of -16.9 and -2.1 kcal/mol, respectively. (1)H NMR study revealed solvent-dependent conformational changes in CalixMPO leading to changes in the electronic properties of the nitronyl group upon H-bonding with the pyrrole groups as also confirmed by calculations. CalixMPO spin trapping of O2(•-) exhibited robust EPR spectra. Kinetic analysis of O2(•-) adduct formation and decay in polar aprotic solvents using UV-vis stopped-flow and EPR methods gave a larger trapping rate constant for CalixMPO and a longer half-life for its O2(•-) adduct compared to the commonly used nitrones. The unusually high reactivity of CalixMPO with O2(•-) was rationalized to be due to the synergy between the α-effect and electrostatic effect by the calix[4]pyrrole moiety on O2(•-) and the nitrone, respectively. This work demonstrates for the first time the application of an anion receptor for the detection of one of the most important radical intermediates in biological and chemical systems (i.e., O2(•-)).

Improved in vitro assays of superoxide anion and 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radical-scavenging activity of isoflavones and isoflavone metabolites

Free radical-scavenging activity of isoflavones and some isoflavone metabolites have been described previously, but the results are inconsistent. The objective of the present study was to find out the pivotal factors that influence an accurate detection of both superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. We here showed for the first time that organic solvents, including methanol, ethanol and acetone, were of strong superoxide radical-scavenging activity at concentrations down to 0.1% (v/v), however, no such activity was observed with acetonitrile at concentrations up to 2.0% (v/v). In DPPH assay, we found that the DPPH radical-scavenging ratio increased together with the extended reaction time. Based on our findings, improved in vitro assays for the detection of radical-scavenging activity of both isoflavones (daidzein and genistein) and isoflavone metabolites, including dihydrodaidzein (DHD), dihydrogenistein (DHG), and O-desmethylangolensin (O-Dma), were established.