Antioxidant enzymes and melatonin levels in patients with bronchial asthma and chronic obstructive pulmonary disease during stable and exacerbation periods

Melatonin improves influenza virus infection-induced acute exacerbation of COPD by suppressing macrophage M1 polarization and apoptosis

BACKGROUND

Influenza A viruses (IAV) are extremely common respiratory viruses for the acute exacerbation of chronic obstructive pulmonary disease (AECOPD), in which IAV infection may further evoke abnormal macrophage polarization, amplify cytokine storms. Melatonin exerts potential effects of anti-inflammation and anti-IAV infection, while its effects on IAV infection-induced AECOPD are poorly understood.

METHODS

COPD mice models were established through cigarette smoke exposure for consecutive 24 weeks, evaluated by the detection of lung function. AECOPD mice models were established through the intratracheal atomization of influenza A/H3N2 stocks in COPD mice, and were injected intraperitoneally with melatonin (Mel). Then, The polarization of alveolar macrophages (AMs) was assayed by flow cytometry of bronchoalveolar lavage (BAL) cells. In vitro, the effects of melatonin on macrophage polarization were analyzed in IAV-infected Cigarette smoking extract (CSE)-stimulated Raw264.7 macrophages. Moreover, the roles of the melatonin receptors (MTs) in regulating macrophage polarization and apoptosis were determined using MTs antagonist luzindole.

RESULTS

The present results demonstrated that IAV/H3N2 infection deteriorated lung function (reduced FEV20,50/FVC), exacerbated lung damages in COPD mice with higher dual polarization of AMs. Melatonin therapy improved airflow limitation and lung damages of AECOPD mice by decreasing IAV nucleoprotein (IAV-NP) protein levels and the M1 polarization of pulmonary macrophages. Furthermore, in CSE-stimulated Raw264.7 cells, IAV infection further promoted the dual polarization of macrophages accompanied with decreased MT1 expression. Melatonin decreased STAT1 phosphorylation, the levels of M1 markers and IAV-NP via MTs reflected by the addition of luzindole. Recombinant IL-1β attenuated the inhibitory effects of melatonin on IAV infection and STAT1-driven M1 polarization, while its converting enzyme inhibitor VX765 potentiated the inhibitory effects of melatonin on them. Moreover, melatonin inhibited IAV infection-induced apoptosis by suppressing IL-1β/STAT1 signaling via MTs.

CONCLUSIONS

These findings suggested that melatonin inhibited IAV infection, improved lung function and lung damages of AECOPD via suppressing IL-1β/STAT1-driven macrophage M1 polarization and apoptosis in a MTs-dependent manner. Melatonin may be considered as a potential therapeutic agent for influenza virus infection-induced AECOPD.

Malondialdehyde as a Potential Oxidative Stress Marker for Allergy-Oriented Diseases: An Update

Malondialdehyde (MDA) is a compound that is derived from the peroxidation of polyunsaturated fatty acids. It has been used as a biomarker to measure oxidative stress in various biological samples in patients who are affected by a wide range of diseases. The aim of our work is to provide an updated overview of the role of MDA as a marker of oxidative stress in allergy-related diseases. We considered studies involving both paediatric and adult patients affected by rhinitis, asthma, urticaria and atopic dermatitis. The measurement of MDA was performed on different types of samples. The reported data highlight the role of serum MDA in inflammatory airway diseases. According to the literature review, the oxidative stress status in asthmatic patients, assessed via MDA determination, appears to worsen in the presence of other allergic airway diseases and in relation to the disease severity. This suggests that MDA can be a suitable marker for monitoring the disease status. However, there are several limitations in the considered studies due to the different samples used and the lack of phenotyping and description of the clinical period of patients examined. In cutaneous allergic diseases, the role of MDA is controversial because of the smallness of the studies and the heterogeneity of the samples and patients.

Impaired Alveolar Re-Epithelialization in Pulmonary Emphysema

Alveolar type II (ATII) cells are progenitors in alveoli and can repair the alveolar epithelium after injury. They are intertwined with the microenvironment for alveolar epithelial cell homeostasis and re-epithelialization. A variety of ATII cell niches, transcription factors, mediators, and signaling pathways constitute a specific environment to regulate ATII cell function. Particularly, WNT/β-catenin, YAP/TAZ, NOTCH, TGF-β, and P53 signaling pathways are dynamically involved in ATII cell proliferation and differentiation, although there are still plenty of unknowns regarding the mechanism. However, an imbalance of alveolar cell death and proliferation was observed in patients with pulmonary emphysema, contributing to alveolar wall destruction and impaired gas exchange. Cigarette smoking causes oxidative stress and is the primary cause of this disease development. Aberrant inflammatory and oxidative stress responses result in loss of cell homeostasis and ATII cell dysfunction in emphysema. Here, we discuss the current understanding of alveolar re-epithelialization and altered reparative responses in the pathophysiology of this disease. Current therapeutics and emerging treatments, including cell therapies in clinical trials, are addressed as well.

The melatonergic pathway and its interactions in modulating respiratory system disorders

Melatonin is a key intracellular neuroimmune-endocrine regulator and coordinator of multiple complex and interrelated biological processes. The main functions of melatonin include the regulation of neuroendocrine and antioxidant system activity, blood pressure, rhythms of the sleep-wake cycle, the retardation of ageing processes, as well as reseting and optimizing mitochondria and thereby the cells of the immune system. Melatonin and its agonists have therefore been mooted as a treatment option across a wide array of medical disorders. This article reviews the role of melatonin in the regulation of respiratory system functions under normal and pathological conditions. Melatonin can normalize the structural and functional organization of damaged lung tissues, by a number of mechanisms, including the regulation of signaling molecules, oxidant status, lipid raft function, optimized mitochondrial function and reseting of the immune response over the circadian rhythm. Consequently, melatonin has potential clinical utility for bronchial asthma, chronic obstructive pulmonary disease, lung cancer, lung vascular diseases, as well as pulmonary and viral infections. The integration of melatonin's effects with the alpha 7 nicotinic receptor and the aryl hydrocarbon receptor in the regulation of mitochondrial function are proposed as a wider framework for understanding the role of melatonin across a wide array of diverse pulmonary disorders.

Targeting Aging Pathways in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) has become a global epidemic and is the third leading cause of death worldwide. COPD is characterized by chronic airway inflammation, loss of alveolar-capillary units, and progressive decline in lung function. Major risk factors for COPD are cigarette smoking and aging. COPD-associated pathomechanisms include multiple aging pathways such as telomere attrition, epigenetic alterations, altered nutrient sensing, mitochondrial dysfunction, cell senescence, stem cell exhaustion and chronic inflammation. In this review, we will highlight the current literature that focuses on the role of age and aging-associated signaling pathways as well as their impact on current treatment strategies in the pathogenesis of COPD. Furthermore, we will discuss established and experimental COPD treatments including senolytic and anti-aging therapies and their potential use as novel treatment strategies in COPD.

Cellular stress responses and dysfunctional Mitochondrial-cellular senescence, and therapeutics in chronic respiratory diseases

The abnormal inflammatory responses due to the lung tissue damage and ineffective repair/resolution in response to the inhaled toxicants result in the pathological changes associated with chronic respiratory diseases. Investigation of such pathophysiological mechanisms provides the opportunity to develop the molecular phenotype-specific diagnostic assays and could help in designing the personalized medicine-based therapeutic approaches against these prevalent diseases. As the central hubs of cell metabolism and energetics, mitochondria integrate cellular responses and interorganellar signaling pathways to maintain cellular and extracellular redox status and the cellular senescence that dictate the lung tissue responses. Specifically, as observed in chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis, the mitochondria-endoplasmic reticulum (ER) crosstalk is disrupted by the inhaled toxicants such as the combustible and emerging electronic nicotine-delivery system (ENDS) tobacco products. Thus, the recent research efforts have focused on understanding how the mitochondria-ER dysfunctions and oxidative stress responses can be targeted to improve inflammatory and cellular dysfunctions associated with these pathologic illnesses that are exacerbated by viral infections. The present review assesses the importance of these redox signaling and cellular senescence pathways that describe the role of mitochondria and ER on the development and function of lung epithelial responses, highlighting the cause and effect associations that reflect the disease pathogenesis and possible intervention strategies.

Associations of Herbs and Nonvitamin Dietary Supplements Use with Clinical Outcomes Among Adult and Pediatric Patients with Asthma in the United States

BACKGROUND

Herbs and nonvitamin dietary supplements (NVDS) have been commonly used among patients with asthma, yet evidence of their impact on patients' clinical outcomes is limited.

OBJECTIVE

This study examined the associations of herbs and NVDS use with asthma episodes and asthma-related emergency department (ED) visits among US adults and pediatric patients with asthma.

METHODS

A cross-sectional analysis of the 2012 National Health Interview Survey data included 2,930 US adults and 1923 children with self-reported asthma. We estimated the prevalence and type of herbs and/or NVDS use and identified factors associated with their use. We then used multivariable logistic regression models to examine the associations between these supplemental medications use and asthma outcomes, controlling for patient-related covariates. All results were weighted to represent national estimates.

RESULTS

Approximately 7.20% of American children and 21.17% of adults with asthma used herbs and/or NVDS in 2012. Herb and/or NVDS users were more likely to be female, non-Hispanic white, living in the West region, having higher family income, and having comorbidities compared with nonusers. Herbs and/or NVDS use was associated with lower likelihood of having asthma-related ED visit (adjusted odds ratio = 0.48; 95% confidence interval: 0.31, 0.75) among adult patients with asthma, but not for pediatric patients with asthma. No association between herbs and/or NVDS use and having an asthma episode was observed in either adults or children.

CONCLUSIONS

This study found high prevalence of herbs and/or NVDS use among US patients with asthma. Potential benefit of these supplemental medications use on asthma-related ED visits might exist for adult patients with asthma.

Melatonin protects against COPD by attenuating apoptosis and endoplasmic reticulum stress via upregulating SIRT1 expression in rats

The apoptosis of bronchial and alveolar epithelial cells plays a key role in chronic obstructive pulmonary disease (COPD). The endoplasmic reticulum (ER) stress induced by cigarette smoke contributes to apoptosis. Previous studies demonstrated that melatonin prevented the development of COPD. In addition, silent information regulator 1 (SIRT1) had a protective effect against COPD. However, it remains unclear whether SIRT1 is involved in the protection of melatonin against COPD. In this study, 32 male Wistar rats were randomly assigned to 4 groups: Control, COPD, COPD + Mel, and COPD + Mel + EX527. Rats were challenged with cigarette smoke and lipopolysaccharide with or without melatonin or EX527 (a selective inhibitor of SIRT1). The lung histopathology, apoptotic index, as well as the protein expressions of cleaved caspase-3, SIRT1, C/EBP homologous protein, and caspase-12 in the lung tissues were measured. These results demonstrated that melatonin attenuated apoptosis and ER stress in the lung tissues of rats with COPD. In addition, melatonin increased SIRT1 expression in lung tissues of rats with COPD, while inhibition of SIRT1 by EX527 upregulated ER stress and abolished the protective effect of melatonin against apoptosis. In conclusion, these findings suggested that melatonin protected against COPD by attenuating apoptosis and ER stress via upregulating SIRT1 expression in rats.

Oxidative stress and macrophages: driving forces behind exacerbations of asthma and chronic obstructive pulmonary disease?

Oxidative stress is a common feature of obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD). Lung macrophages are key innate immune cells that can generate oxidants and are known to display aberrant polarization patterns and defective phagocytic responses in these diseases. Whether these characteristics are linked in one way or another and whether they contribute to the onset and severity of exacerbations in asthma and COPD remain poorly understood. Insight into oxidative stress, macrophages, and their interactions may be important in fully understanding acute worsening of lung disease. This review therefore highlights the current state of the art regarding the role of oxidative stress and macrophages in exacerbations of asthma and COPD. It shows that oxidative stress can attenuate macrophage function, which may result in impaired responses toward exacerbating triggers and may contribute to exaggerated inflammation in the airways.

Low concentrations of clarithromycin upregulate cellular antioxidant enzymes and phosphorylation of extracellular signal-regulated kinase in human small airway epithelial cells

BACKGROUND

It is well known that low-dose, long-term macrolide therapy is effective against chronic inflammatory airway diseases. Oxidative stress is considered to be a key pathogenesis factor in those diseases. However, the mechanism of action of low-dose, long-term macrolide therapy remains unclear. We have reported that clarithromycin (CAM), which is a representative macrolide antibiotic, could inhibit hydrogen peroxide (H2O2)-induced reduction of the glutathione (GSH)/glutathione disulfide (GSSG) ratio in human small airway epithelial cells (SAECs), via the maintenance of GSH levels through an effect on γ-glutamylcysteine synthetase (γ-GCS) expression. In this study, we examined the influence of CAM against H2O2-induced activities of cellular antioxidant enzymes and phosphorylated extracellular signal regulatory kinase (p-ERK) using SAECs, the main cells involved in chronic airway inflammatory diseases.

METHODS

SAECs were pretreated with CAM (1, 5, and 10 μM) for 72 h, and subsequently exposed to H2O2 (100 μM) for 0.5-2 h. Levels of GSH and GSSG, and activities of glutathione peroxidase (GPx)-1, glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), heme oxygenase (HO)-1 and p-ERK were assayed. mRNA expressions of GPx-1 and HO-1 were measured using the real-time reverse transcription polymerase chain reaction (RT-PCR). Tukey's multiple comparison test was used for analysis of statistical significance.

RESULTS

Pretreatment with low-dose (1 and 5 μM) CAM for 72 h inhibited H2O2-induced reductions of GPx-1, GR, SOD, CAT and HO-1 activities, and mRNA expressions of GPx-1 and HO-1, and improved the GSH/GSSG ratio. However, these alterations were not observed after pretreatment with high-dose (10 μM) CAM, which suppressed phosphorylation of cell proliferation-associated ERK to cause a significant (p < 0.01) decrease in cell viability.

CONCLUSIONS

CAM is efficacious against deterioration of cellular antioxidant enzyme activity caused by oxidative stress under low-dose, long-term treatment conditions. On the other hand, pretreatment with high-dose CAM suppressed phosphorylation of cell proliferation-associated ERK and decreased cell viability. The present study may provide additional evidence as to why low-dose, long-term administration of macrolides is effective for treating chronic inflammatory airway diseases.

Role of ROS and Nutritional Antioxidants in Human Diseases

The overproduction of reactive oxygen species (ROS) has been implicated in the development of various chronic and degenerative diseases such as cancer, respiratory, neurodegenerative, and digestive diseases. Under physiological conditions, the concentrations of ROS are subtlety regulated by antioxidants, which can be either generated endogenously or externally supplemented. A combination of antioxidant-deficiency and malnutrition may render individuals more vulnerable to oxidative stress, thereby increasing the risk of cancer occurrence. In addition, antioxidant defense can be overwhelmed during sustained inflammation such as in chronic obstructive pulmonary diseases, inflammatory bowel disease, and neurodegenerative disorders, cardiovascular diseases, and aging. Certain antioxidant vitamins, such as vitamin D, are essential in regulating biochemical pathways that lead to the proper functioning of the organs. Antioxidant supplementation has been shown to attenuate endogenous antioxidant depletion thus alleviating associated oxidative damage in some clinical research. However, some results indicate that antioxidants exert no favorable effects on disease control. Thus, more studies are warranted to investigate the complicated interactions between ROS and different types of antioxidants for restoration of the redox balance under pathologic conditions. This review highlights the potential roles of ROS and nutritional antioxidants in the pathogenesis of several redox imbalance-related diseases and the attenuation of oxidative stress-induced damages.

Geroprotectors as a therapeutic strategy for COPD - where are we now?

Although current therapies in chronic obstructive pulmonary disease (COPD) improve the quality of life, they do not satisfactorily reduce disease progression or mortality. There are still many gaps in knowledge about the cellular, molecular, and genetic mechanisms contributing to pathobiology of this disease. However, increasing evidence suggests that accelerated aging, chronic systemic inflammation, and oxidative stress play major roles in pathogenesis in COPD, thus opening new opportunities in therapy. Therefore, the aim of our review was to describe and discuss some of the most widely used therapeutics that affect the root cause of aging and oxidative stress (metformin, melatonin, sirolimus, statins, vitamin D, and testosterone) in context of COPD therapy.

Decreased activity of butyrylcholinesterase in blood plasma of patients with chronic obstructive pulmonary disease

INTRODUCTION

Butyrylcholinesterase (BChE) is involved in the metabolism of endogenous lipids and xenobiotics, such as esters of carboxylic or phosphoric acids. Butyrylcholinesterase activity is associated with both inflammation and oxidative stress. Changes in the activity of this enzyme have been observed in various diseases such as liver cirrhosis, diabetes, neurodegenerative disease and others.

MATERIAL AND METHODS

The study involved 30 patients with chronic obstructive pulmonary disease (COPD) and 18 healthy subjects. The COPD patients were divided according to the severity of the disease by applying the classification of COPD based on GOLD standards for forced expiratory volume in 1 s (FEV₁) and the FEV₁/forced expiratory volume (FVC) ratio. The control group comprised blood samples collected from healthy subjects without concomitant diseases related to the respiratory system. Butyrylcholinesterase activity, lipid peroxidation and total antioxidant capacity (TAC) were determined in the blood plasma.

RESULTS

A significant (p < 0.05) decrease in the activity of BChE, associated with an increase in lipid peroxidation and a decrease in the total antioxidant capacity, was observed in blood plasma of patients with chronic obstructive pulmonary disease.

CONCLUSIONS

The study shows for the first time that activity of BChE in the blood plasma of patients diagnosed with chronic obstructive pulmonary disease is considerably reduced compared with healthy subjects. These changes were accompanied by a decrease of TAC and an increase of lipid peroxidation, which suggests that they may be related to the oxidative stress induced by COPD disease.

Melatonin: Possibilities for use in the treatment of asthma

Asthma is a serious health problem affecting all age groups. Melatonin or its agonists are commonly used to treat many diseases, but there are conflicting data on asthma therapy. This paper analyzes researches on the possible use of melatonin in the therapy of asthma. Melatonin is a potent antioxidant and a vasodilator, but in some experiments, it can act as a pro-oxidant and a vasoconstrictor, which may depend on the duration of use. It has been suggested that circadian rhythms should be corrected in asthmatics to optimize the desired effects of drugs and to reduce the severity of their adverse reactions. Disordered diurnal variations in the salivary levels of melatonin and cortisol are detectable in patients with asthma and may be implicated in its pathogenesis. In addition, the conflicting data on the effect of melatonin on the development of asthma are associated with an incomplete view of the factors influencing the level of melatonin. Thus, to study the effects of melatonin, it is necessary to take into account the greatest possible factors that may influence the level of melatonin and the course of asthma: a daily diet in terms of the use of caffeine, alcohol, sleep-wakefulness pattern, sleep quality proper, and drowsiness during the daytime, social burden, the level of anxiety and stress resistance, and to investigate the levels of endogenous melatonin or its derivatives, immune status, oxidative stress intensity, etc. Obviously, the use of melatonin in the therapy of asthma can be considered, by applying a personalized approach.

Sleep, Melatonin, and the Menopausal Transition: What Are the Links?

The pineal hormone Melatonin plays an important role in the regulation of the circadian sleep/wake cycle, mood, and perhaps immune functions, carcinogensis and reproduction. The human circadian rhythm of melatonin release from the pineal gland is tightly synchronized with the habitual hours of sleep. Peri- and postmenopausal women often complain of difficulties initiating and/or maintaining sleep, with frequent nocturnal and early morning awakenings. In this review we discuss the pathophysiology of melatonin function as it relates to sleep disorders in menopausal women, highlighting the potential use of exogenous melatonin during the menopausal transition and beyond.

Antioxidant Supplementation in the Treatment of Aging-Associated Diseases

Oxidative stress is generally considered as the consequence of an imbalance between pro- and antioxidants species, which often results into indiscriminate and global damage at the organismal level. Elderly people are more susceptible to oxidative stress and this depends, almost in part, from a decreased performance of their endogenous antioxidant system. As many studies reported an inverse correlation between systemic levels of antioxidants and several diseases, primarily cardiovascular diseases, but also diabetes and neurological disorders, antioxidant supplementation has been foreseen as an effective preventive and therapeutic intervention for aging-associated pathologies. However, the expectations of this therapeutic approach have often been partially disappointed by clinical trials. The interplay of both endogenous and exogenous antioxidants with the systemic redox system is very complex and represents an issue that is still under debate. In this review a selection of recent clinical studies concerning antioxidants supplementation and the evaluation of their influence in aging-related diseases is analyzed. The controversial outcomes of antioxidants supplementation therapies, which might partially depend from an underestimation of the patient specific metabolic demand and genetic background, are presented.

Cigarette smoke-induced induction of antioxidant enzyme activities in airway leukocytes is absent in active smokers with COPD

BACKGROUND

Oxidative injury to the airway has been proposed as an important underlying mechanism in the pathogenesis of chronic obstructive pulmonary disease (COPD). As the extent of oxidant-mediated damage is dependent on the endogenous antioxidant defences within the airways, we examined whether COPD was associated with deficiencies in the antioxidant network within the respiratory tract lining fluids (RTLFs) and resident airway leukocytes. We hypothesised that COPD would be associated with both basal depression of antioxidant defences and impaired adaptive antioxidant responses to cigarette smoke.

METHODS

Low molecular weight and enzymatic antioxidants together with metal-handling proteins were quantified in bronchoalveolar lavage fluid and airway leukocytes, derived from current (n=9) and ex-smoking COPD patients (n=15), as well as from smokers with normal lung function (n=16) and healthy never smokers (n=13).

RESULTS

Current cigarette smoking was associated with an increase in ascorbate and glutathione within peripheral RTLFs in both smokers with normal lung function compared with healthy never smokers and in COPD smokers compared with COPD ex-smokers. In contrast, intra-cellular antioxidant enzyme activities (glutathione peroxidase, glutathione reductase, and catalase) were only up-regulated in smokers with normal lung function compared with healthy never smokers and not in actively smoking COPD patients relative to COPD ex-smokers.

CONCLUSIONS

We found no evidence of impaired basal antioxidant defences, within either the RTLFs or airway leukocytes in stable ex-smoking COPD patients compared with healthy never smoking controls. Current cigarette smoking induced an up-regulation of low molecular weight antioxidants in the RTLFs of both control subjects with normal lung function and patients with COPD. Importantly, the present data demonstrated a cigarette smoke-induced increase in intra-cellular antioxidant enzyme activities only within the smokers with normal lung function, implying that patients with COPD who continue to smoke will experience enhanced oxidative stress, prompting disease progression.

[Genetic and biochemical mechanisms of involvement of antioxidant defense enzymes in the development of bronchial asthma]

In the present review we have analyzed and summarized recent literature data on genetic and biochemical mechanisms responsible for involvement of antioxidant defense enzymes in the etiology and pathogenesis of bronchial asthma. It has been shown that the mechanisms of asthma development are linked with genetically determined abnormalities in the functioning of antioxidant defense enzymes. These alterations are accompanied by a systemic imbalance between oxidative and anti-oxidative reactions with the shift of the redox state toward increased free radical production and oxidative stress, a key element in the pathogenesis of bronchial asthma.

Cigarette smoke causes caspase-independent apoptosis of bronchial epithelial cells from asthmatic donors

BACKGROUND

Epidemiologic studies have demonstrated important links between air pollution and asthma. Amongst these pollutants, environmental cigarette smoke is a risk factor both for asthma pathogenesis and exacerbation. As the barrier to the inhaled environment, the bronchial epithelium is a key structure that is exposed to cigarette smoke.

OBJECTIVES

Since primary bronchial epithelial cells (PBECs) from asthmatic donors are more susceptible to oxidant-induced apoptosis, we hypothesized that they would be susceptible to cigarette smoke-induced cell death.

METHODS

PBECs from normal and asthmatic donors were exposed to cigarette smoke extract (CSE); cell survival and apoptosis were assessed by fluorescence-activated cell sorting, and protective effects of antioxidants evaluated. The mechanism of cell death was evaluated using caspase inhibitors and immunofluorescent staining for apoptosis-inducing factor (AIF).

RESULTS

Exposure of PBEC cultures to CSE resulted in a dose-dependent increase in cell death. At 20% CSE, PBECs from asthmatic donors exhibited significantly more apoptosis than cells from non-asthmatic controls. Reduced glutathione (GSH), but not ascorbic acid (AA), protected against CSE-induced apoptosis. To investigate mechanisms of CSE-induced apoptosis, caspase-3 or -9 inhibitors were tested, but these failed to prevent apoptosis; in contrast, CSE promoted nuclear translocation of AIF from the mitochondria. GSH reduced the number of nuclear-AIF positive cells whereas AA was ineffective.

CONCLUSION

Our results show that PBECs from asthmatic donors are more susceptible to CSE-induced apoptosis. This response involves AIF, which has been implicated in DNA damage and ROS-mediated cell-death. Epithelial susceptibility to CSE may contribute to the impact of environmental tobacco smoke in asthma.

Increased oxidative stress and altered levels of nitric oxide and peroxynitrite in Tunisian patients with chronic obstructive pulmonary disease: correlation with disease severity and airflow obstruction

This study was aimed to evaluate the oxidant-antioxidant imbalance in the pathogenesis of chronic obstructive pulmonary disease (COPD) in Tunisians. We assessed 16 parameters related to the oxidative status that include malondialdehyde (MDA), total protein carbonyls (PCs), and advanced oxidation protein products (AOPP). We also examined the activity of glutathione peroxydase (GSH-Px), catalase, and superoxide dismutase (SOD) in the plasma and erythrocytes. Levels of total thiols, reduced glutathione (GSH), total antioxidant status (TAS), hydrogen peroxide, ascorbic acid, iron, and protein sulfhydryls were determined using spectrophotometry. We also evaluated the level of nitric oxide (NO) and peroxynitrite in plasma from COPD patients and healthy controls. Estimation of DNA damage was determined using the comet assay. Pulmonary functional tests were performed by body plethysmography. Levels of MDA, PC, DNA damage, and AOPP were significantly increased while total thiols, GSH, and TAS were decreased in COPD patients. GSH-Px activity was higher in COPD patients while no difference was found for catalase and SOD. We also observed a lower level of NO and peroxynitrite in COPD patients. Decreased levels of peroxynitrite were found to correlate with disease progression, as well as with forced expiratory volume in 1 s/forced vital capacity among COPD patients. Multivariate analysis revealed that NO is associated with pathological pathways that help to predict patient outcome independently of the degree of airflow obstruction. These results indicate the presence of a systemic oxidative stress and highlight the importance of NO and peroxynitrite as major effectors in COPD development and airflow obstruction.

Melatonin and atopy: role in atopic dermatitis and asthma

Melatonin may have important immunostimulatory actions in allergic diseases, in addition to its well-known antioxidant and cytoprotective effects in several inflammatory conditions. The activation of the immune system leads to free radical production associated with decreased melatonin levels and depressed antioxidant enzyme activities in several inflammatory diseases. Many skin disorders, including atopic dermatitis, are accompanied by infiltration and activation of mast cells, which release vasoactive and proinflammatory mediators. Experimental data suggest that melatonin inhibits development of atopic eczema and reduces serum total IgE and IL-4. Allergic asthma is a condition characterized by bronchial hyperresponsiveness and the presence of IgE antibodies in response to inhaled allergens; often there is also enhanced total serum IgE levels. Melatonin regulates smooth muscle tone and influences the immune response. Melatonin may, however, act as a pro-inflammatory agent in asthma leading to bronchial constriction. The safety of melatonin as a sleep-inducing agent has been confirmed in asthmatic subjects, but its routine use is not recommended in bronchial asthma. This review summarizes what is known about the role of melatonin as an immunomodulatory agent in asthma and atopic eczema.

Pulmonary function changes in rats with taurocholate-induced pancreatitis are attenuated by pretreatment with melatonin

Melatonin is a free radical scavenger and broad-spectrum antioxidant with immunomodulatory effects. We studied the effects of melatonin on changes in lung function, oxidative/nitrosative stress, and inflammatory cell sequestration in an acute pancreatitis (AP)-associated lung inflammation model. Acute pancreatitis was induced by injection of 5% sodium taurocholate into the pancreatic duct of rats. Animals were randomized into control, AP, and a melatonin pretreatment (10 mg/kg)/AP group. Functional residual capacity (FRC), lung compliance (Cchord), expiratory flow rate at 50% (FEF50), airway resistance index (RI), and peak expiratory flow rate (PEF) were evaluated. White blood cell count (WBC) and hydrogen peroxide, lung lavage fluid WBC, methylguanidine, protein, lactic dehydrogenase (LDH), nitric oxide (NO), and leukotriene B4 (LTB4) levels were determined. Lung wet-to-dry weight ratio, peroxynitrite, and inducible nitric oxide synthase (NOS) mRNA and protein were measured. AP induction resulted in reductions in FRC, Cchord, FEF50, and PEF, and increase in RI and lung wet-to-dry weight ratio. Blood and lung lavage fluid WBC, lavage fluid LDH, protein, and blood hydrogen peroxide also increased. Levels of hydroxyl radicals, nitric oxide, and LTB4 in lung lavage fluid, inducible NOS mRNA, protein expression, and peroxynitrite in lung tissue also were significantly elevated. Pretreatment with melatonin attenuated obstructive and restrictive ventilatory insufficiency induced by AP. Blood and lavage WBC, lavage LDH and protein, lung edema, oxidative/nitrosative stress, and lipoxygenase pathway derivatives were also significantly attenuated by melatonin. We conclude that melatonin decreases AP-induced obstructive and restrictive lung function changes via its antioxidant and anti-inflammatory properties.

Arctigenin exhibits relaxation effect on bronchus by affecting transmembrane flow of calcium

Arctigenin, a lignan extract from Arctium lappa (L.), exhibits anti-inflammation, antioxidation, vasodilator effects, etc. However, the effects of arctigenin on bronchus relaxation are not well investigated. This study aimed to investigate how arctigenin regulates bronchus tone and calcium ion (Ca(2+)) flow. Trachea strips of guinea pigs were prepared for testing the relaxation effect of arctigenin to acetylcholine, histamine, KCl, and CaCl2, respectively. Furthermore, L-type calcium channel currents were detected by patch-clamp, and intracellular Ca(2+) concentration was detected by confocal microscopy. The results showed that arctigenin exhibited relaxation effect on tracheae to different constrictors, and this was related to decreasing cytoplasmic Ca(2+) concentration by inhibiting Ca(2+) influx partly through L-type calcium channel as well as promoting Ca(2+) efflux. In summary, this study provides new insight into the mechanisms by which arctigenin exhibits relaxation effect on bronchus and suggests its potential use for airway disease therapy.

Systemic levels of ceruloplasmin oxidase activity in allergic asthma and allergic rhinitis

CONTEXT

The role of ceruloplasmin oxidase activity (COA) involving the interaction of oxidant and antioxidant balance in allergic diseases is still unknown.

OBJECTIVE

Our study was designed to examine the changes in COAs in severe persistent asthma-allergic rhinitis, new diagnosed allergic asthma-allergic rhinitis and allergic rhinitis patients.

METHODS

The study included 20 age- and sex-matched healthy individuals as control (Group I); Group II included 15 newly diagnosed allergic asthma-allergic rhinitis; Group III included 15 patients with severe persistent asthma-allergic rhinitis and in the fourth group there were 20 patients with allergic rhinitis. Group III was divided in two groups, severe persistent asthma-allergic rhinitis who were pre-(III-A) and post-treated (III-B) with omalizumab. Group IV was divided to two groups, pretreatment (IV-A) and posttreatment (IV-B) with specific subcutaneous immunotherapy modalities. All the posttreatment measurements were 12 months after the therapy. All the patients were assessed by the skin prick test, high sensitive C-reactive protein (hs-CRP) and COA.

RESULTS

There were significant differences between Group I and Groups III-A, III-B, IV-A and IV-B; Group II and Groups III-A, III-B, IV-A and IV-B; Group III-A and Groups III-B, IV-A and IV-B; Group III-A and Groups IV-A and IV-B; and Group IV-A and IV-B. Interestingly, there was a correlation between the hs-CRP and COA levels in Group III-A.

CONCLUSIONS

Our data suggest that hs-CRP and COA levels might be an indicator of an inflammation and important in revelation of patients with allergy related diseases, especially of asthma patients.

Melatonin reduces lung oxidative stress in patients with chronic obstructive pulmonary disease: a randomized, double-blind, placebo-controlled study

Chronic obstructive pulmonary disease (COPD), a major cause of death and disability, is attributed to an abnormal inflammatory response by the lungs to noxious substances, primarily from cigarette smoke. Although oxidative stress is regarded as central to the pathogenesis of COPD, very few studies have examined the effects of antioxidants in this condition. This was a randomized, double-blind, placebo-controlled study on the effects of melatonin in COPD. Thirty-six consecutive patients with clinically stable moderate to very severe COPD (30 men; mean±S.D.=66.6±7.8yr) were randomized to receive 3mg melatonin (N=18) or placebo for 3 months. Oxidative stress was evaluated by 8-isoprostane levels in exhaled breath condensate at baseline (T0) and after one (T1), two (T2), and three months (T3) of treatment. Additionally, exhaled breath condensate levels of IL-8, dyspnea severity (Medical Research Council scale), lung function (spirometry), and functional exercise capacity (six min walk test) were compared at baseline and after treatment. Patients receiving melatonin showed a decrease in 8-isoprostane (T0: mean±S.E.M.=20.41±2.92pg/mL; T1: 18.56±2.68pg/mL; T2: 12.68±2.04pg/mL; T3: 12.70±2.18pg/mL; P=0.04; repeated measures ANOVA) with significant differences from baseline after 2 (P=0.03) and 3months (P=0.01). Dyspnea was improved by melatonin (P=0.01), despite no significant changes in lung function or exercise capacity. Placebo-treated patients, but not those who were given melatonin, showed an increase in IL-8 (P=0.03). In summary, melatonin administration reduced oxidative stress and improved dyspnea in COPD. Further studies are necessary to determine the potential role for melatonin in the long-term management of these patients.

Geroprotectors as a novel therapeutic strategy for COPD, an accelerating aging disease

Chronic obstructive pulmonary disease (COPD) progresses very slowly and the majority of patients are therefore elderly. COPD is characterized by an abnormal persistent inflammatory response to noxious environmental stimuli and there are increasing evidences for a close relationship between premature aging and chronic inflammatory diseases. Thus, COPD is considered to be a disease of an accelerating aging. In this review, we collected the evidence for roles of aging on pathogenesis of COPD and considered future therapeutic strategy for COPD based on this senescence hypothesis. Since calorie restriction has been proved to extend lifespan, many efforts were made to clarify the molecular mechanism of aging. Aging is defined as the progressive decline of homeostasis that occurs after the reproductive phase of life is complete, leading to an increasing risk of disease or death due to impaired DNA repair after damage by oxidative stress or telomere shortening as a result of repeated cell division. During aging, pulmonary function progressively deteriorates; innate immunity is impaired and pulmonary inflammation increases, accompanied by structural changes, such as an enlargement of airspaces. Noxious environmental gases, such as cigarette smoke, may worsen these aging-related events in the lung or accelerate aging of the lung due to reduction in anti-aging molecules and/or stimulation of aging molecules. Aging signaling are complex but conserved in divert species, such as worm, fruit fry, rodent and humans. Especially the insulin like growth factor (IGF-1) signaling was well documented. Geroprotectors are therapeutics that affect the root cause of aging and age-related diseases, and thus prolong the life-span of animals. Most of geroprotectors such as melatonin, metformin, rapamycin and resveratrol are anti-oxidant or anti-aging molecule regulators. Therefore, geroprotection for the lung might be an attractive approach for the treatment of COPD by preventing premature aging of lung.

Glutathione redox control of asthma: from molecular mechanisms to therapeutic opportunities

Asthma is a chronic inflammatory disorder of the airways associated with airway hyper-responsiveness and airflow limitation in response to specific triggers. Whereas inflammation is important for tissue regeneration and wound healing, the profound and sustained inflammatory response associated with asthma may result in airway remodeling that involves smooth muscle hypertrophy, epithelial goblet-cell hyperplasia, and permanent deposition of airway extracellular matrix proteins. Although the specific mechanisms responsible for asthma are still being unraveled, free radicals such as reactive oxygen species and reactive nitrogen species are important mediators of airway tissue damage that are increased in subjects with asthma. There is also a growing body of literature implicating disturbances in oxidation/reduction (redox) reactions and impaired antioxidant defenses as a risk factor for asthma development and asthma severity. Ultimately, these redox-related perturbations result in a vicious cycle of airway inflammation and injury that is not always amenable to current asthma therapy, particularly in cases of severe asthma. This review will discuss disruptions of redox signaling and control in asthma with a focus on the thiol, glutathione, and reduced (thiol) form (GSH). First, GSH synthesis, GSH distribution, and GSH function and homeostasis are discussed. We then review the literature related to GSH redox balance in health and asthma, with an emphasis on human studies. Finally, therapeutic opportunities to restore the GSH redox balance in subjects with asthma are discussed.

Coenzyme Q10, copper, zinc, and lipid peroxidation levels in serum of patients with chronic obstructive pulmonary disease

Severity of chronic obstructive pulmonary disease (COPD) exacerbation is associated with increased level of copper (Cu), zinc (Zn), and lipid peroxidation (malodialdehyde, MDA). The aim of this study was to investigate the levels of lipid peroxidation, Coenzyme Q10 (CoQ10), Zn, and Cu in the COPD exacerbations. Forty-five patients with COPD acute exacerbation and 45 healthy smokers as control group were used in the study. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were lower in exacerbation group than in control. C- reactive protein levels, white blood cell count, and sedimentation rate were significantly (p<0.001) higher in patients than in control. CoQ10 level and Cu/Zn ratio was significantly (p<0.05) lower in patients than in control, although MDA, Cu, and Zn levels were significantly (p<0.05) higher in patients than in control. Negative correlations were found among MDA, Cu, Zn, FEV1, and FVC values in exacerbation and control subjects (p<0.05). In conclusion, we observed that oxidative stress in the exacerbation period of COPD patients was increased. The decrease in CoQ10 level and Cu/Zn ratio and elevation in Cu and Zn levels observed in the patients probably result from the defense response of organism and are mediated by inflammatory-like substances.

The association between adult asthma and superoxide dismutase and catalase gene activity

BACKGROUND

Adult asthma is caused by interaction effects of multiple genetic and environmental factors. Some studies have suggested that antioxidant enzyme activity and gene polymorphisms may play important roles in the context of asthma. Therefore, our study objectives were to investigate the association between asthma, antioxidant activities and the polymorphisms of manganese superoxide dismutase (Mn-SOD) or catalase (CAT).

MATERIALS AND METHODS

A case-control study, for which we recruited 250 asthmatic adults and 250 age- and sex-matched controls. All subjects completed a questionnaire. Waist and hip circumference measurements, a lung function test and DNA genotyping were performed. In total, 50 incident cases and 50 matched controls who were non-smokers or had quit smoking for at least 1 year were selected in order to investigate SOD and CAT activity levels.

RESULTS

In our study, we did not find a significant association between Mn-SOD Ala16Val, CAT C-262T and asthma. The level of SOD activity in new-onset asthma patients was significantly lower than in control subjects (p < 0.0005). The level of CAT activity in new-onset asthma patients was significantly higher than in control subjects (p < 0.0005).

CONCLUSIONS

The levels of SOD and CAT activity were significantly related to adult asthma. SOD and CAT activity may be good tools to differentiate potential asthma sufferers. This would enable us to further investigate the mechanism of defective antioxidant enzymes in the context of asthma pathogenesis.

Correlation of EPHX1, GSTP1, GSTM1, and GSTT1 genetic polymorphisms with antioxidative stress markers in chronic obstructive pulmonary disease

This study was undertaken to ascertain if a relationship existed between oxidative status and polymorphisms of microsomal epoxide hydrolase X1 (EPHX1), glutathione S-transferase P1 (GSTP1), GSTM1, and GSTT1 in chronic obstructive pulmonary disease (COPD). Erythrocyte glutathione peroxidase (GSH-px), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), and plasma GST activities and total antioxidant status (TAS) as antioxidative stress markers were determined and compared either with individual and combined genotypes of EPHX1 exon 3, GSTP1 exon 5, GSTM1, and GSTT1 polymorphisms in COPD patients and healthy controls from the central area of Tunisia. Statistical data processing revealed significantly lower GSH-px, GR, SOD, CAT, GST, and TAS values in COPD patients in comparison to the control group (P < .001). As for genotypes, there was a no significant association in each of the 6 parameters and individual genotypes (P > .05). A significant correlation between the studied parameters and combined null GSTM1/null GSTT1 (GSH-px: P < .001, GR: P = .026, CAT: P = .018, GST: P = .022, TAS: P = .046), His113His EPHX1/null GSTM1 (GSH-px: P = .001, GST: P = .0012, TAS: P = .013), His113His EPHX1/Val105Val GSTP1 (GSH-px: P = .048, CAT: P = .026, GST: P = .031), and null GSTM1/Val105Val GSTP1 (GSH-px: P = .011, GR: P = .0028, GST: P = .0054, TAS: P = .032) was found in patients. In conclusion, combined genetic polymorphisms of GSTM1, GSTT1, GSTP1, and EPHX1 may have favorable effects on redox balance in COPD patients.

Glutathione biochemistry in asthma

BACKGROUND

Oxidative stress in an important hallmark of asthma and much research has therefore focused on the predominant antioxidant in the lungs, namely the tripeptide glutathione.

MAJOR CONCLUSIONS

In lung samples of patients with asthma increased levels of glutathione are typically observed, which appear to relate to the level of pulmonary inflammation and are therefore regarded as an adaptive response to the associated oxidative stress. Also in blood samples increased total GSH levels have been reported, representing the systemic inflammatory component of the disease. In addition, a number of the antioxidant enzymes involved in the maintenance of the GSH/GSSG ratio as well as enzymes that utilize GSH have been found to be altered in the lungs and blood of asthmatics and will be summarized in this review. Very few studies have however linked enzymatic alterations to GSH levels or found that either of these correlated with disease severity. Some animal studies have started to investigate the pathophysiological role of GSH biochemistry in asthma and have yielded surprising results. Important in this respect is the physiological role of the GSH redox equilibrium in determining the outcome of immune responses, which could be deregulated in asthmatics and contribute to the disease.

SCOPE OF REVIEW

Clinical data as well as animal and cell culture studies regarding these aspects of GSH in the context of asthma will be summarized and discussed in this review. This article is part of a Special Issue entitled: Biochemistry of Asthma.

Oral melatonin attenuates lung inflammation and airway hyperreactivity induced by inhalation of aerosolized pancreatic fluid in rats

Melatonin is a free radical scavenger with potent antioxidant properties and immunomodulatory effects. The purpose of this study was to determine the effects of orally administered melatonin in a pancreatic fluid (PF)-induced lung inflammation and airway hyperreactivity model. Aerosolized PF was introduced into airways to induce inflammation in rats. Animals were randomized into three experimental groups: sham treated; PF treated (200 μL/kg); and PF with melatonin (10 mg/kg) pretreatment. Airway reactivity to methacholine, airflow and airway resistance, bronchoalveolar lavage (BAL) cellular differential, the tumor necrosis factor α (TNFα) level, lavage nitric oxide, hydroxyl radical, and lactic dehydrogenase (LDH) were compared among groups. mRNA expressions of inducible nitric oxide synthase (iNOS) and TNFα in lung tissues were determined by real-time polymerase chain reaction. Protein expressions of iNOS and nitrotyrosine and lung tissue myeloperoxidase (MPO) activity were determined using an ELISA assay. Oral melatonin treatment indicated anti-inflammatory efficacy as evidenced by decreased methacholine sensitivity by 24% and airway obstruction by 28%, reduction in BAL eosinophil (P < 0.01) and neutrophil counts (P < 0.05), LDH (P < 0.05), and TNFα concentrations (P < 0.05) when compared to levels in sham-treated rats. Melatonin-treated animals also had reduced nitric oxide and hydroxyl radical concentrations (P < 0.05) in lavage fluid. Oral melatonin significantly reduced mRNA and protein expression of iNOS (P < 0.05 and P < 0.01, respectively), TNFα (P < 0.05), nitrotyrosine (P < 0.05), and MPO activity (P < 0.05) in lung tissues when compared with the sham-treated animals. These results suggest that oral treatment with melatonin had a beneficial effect on PF-induced obstructive ventilatory insufficiency by attenuating nitrosative and oxidative stress.

Pathogenesis of inflammation and repair in advanced COPD

Chronic obstructive pulmonary disease is characterized by an abnormal persistent inflammatory response to noxious environmental stimuli, most commonly cigarette smoke. Although cigarette smoking elicits airway inflammation in all of those who smoke, persistent inflammation and clinically significant COPD occurs in only a minority of smokers. The pathogenesis of COPD involves the recruitment and regulation of neutrophils, macrophages, and lymphocytes to the lung, as well as the induction of oxidative stress, all of which result in lung parenchymal destruction and airway remodeling. Recent research has generated a greater understanding of the mechanisms responsible for COPD development, including new concepts in T cell biology and the increasing recognition that the processes governing lung cell apoptosis are upregulated. We are also starting to understand the reasons for continued inflammation even after smoking cessation, which accelerates the rate of lung function decline in COPD. Herein we review our current knowledge of the inflammatory pathways involved in COPD pathogenesis, as well as newer concepts that have begun to unfold in recent years.