Effect of CArbocisteine in Prevention of exaceRbation of chronic obstructive pulmonary disease (CAPRI study): An observational study

Reactive oxygen species, toxicity, oxidative stress, and antioxidants: chronic diseases and aging

A physiological level of oxygen/nitrogen free radicals and non-radical reactive species (collectively known as ROS/RNS) is termed oxidative eustress or "good stress" and is characterized by low to mild levels of oxidants involved in the regulation of various biochemical transformations such as carboxylation, hydroxylation, peroxidation, or modulation of signal transduction pathways such as Nuclear factor-κB (NF-κB), Mitogen-activated protein kinase (MAPK) cascade, phosphoinositide-3-kinase, nuclear factor erythroid 2-related factor 2 (Nrf2) and other processes. Increased levels of ROS/RNS, generated from both endogenous (mitochondria, NADPH oxidases) and/or exogenous sources (radiation, certain drugs, foods, cigarette smoking, pollution) result in a harmful condition termed oxidative stress ("bad stress"). Although it is widely accepted, that many chronic diseases are multifactorial in origin, they share oxidative stress as a common denominator. Here we review the importance of oxidative stress and the mechanisms through which oxidative stress contributes to the pathological states of an organism. Attention is focused on the chemistry of ROS and RNS (e.g. superoxide radical, hydrogen peroxide, hydroxyl radicals, peroxyl radicals, nitric oxide, peroxynitrite), and their role in oxidative damage of DNA, proteins, and membrane lipids. Quantitative and qualitative assessment of oxidative stress biomarkers is also discussed. Oxidative stress contributes to the pathology of cancer, cardiovascular diseases, diabetes, neurological disorders (Alzheimer's and Parkinson's diseases, Down syndrome), psychiatric diseases (depression, schizophrenia, bipolar disorder), renal disease, lung disease (chronic pulmonary obstruction, lung cancer), and aging. The concerted action of antioxidants to ameliorate the harmful effect of oxidative stress is achieved by antioxidant enzymes (Superoxide dismutases-SODs, catalase, glutathione peroxidase-GPx), and small molecular weight antioxidants (vitamins C and E, flavonoids, carotenoids, melatonin, ergothioneine, and others). Perhaps one of the most effective low molecular weight antioxidants is vitamin E, the first line of defense against the peroxidation of lipids. A promising approach appears to be the use of certain antioxidants (e.g. flavonoids), showing weak prooxidant properties that may boost cellular antioxidant systems and thus act as preventive anticancer agents. Redox metal-based enzyme mimetic compounds as potential pharmaceutical interventions and sirtuins as promising therapeutic targets for age-related diseases and anti-aging strategies are discussed.

Clinical Efficacy of Carbocysteine in COPD: Beyond the Mucolytic Action

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease with a versatile and complicated profile, being the fourth most common single cause of death worldwide. Several research groups have been trying to identify possible therapeutic approaches to treat COPD, such as the use of mucoactive drugs, which include carbocysteine. However, their role in the treatment of patients suffering from COPD remains controversial due to COPD's multifaceted profile. In the present review, 72 articles, published in peer-reviewed journals with high impact factors, are analyzed in order to provide significant insight and increase the knowledge about COPD considering the important contribution of carbocysteine in reducing exacerbations via multiple mechanisms. Carbocysteine is in fact able to modulate mucins and ciliary functions, and to counteract viral and bacterial infections as well as oxidative stress, offering cytoprotective effects. Furthermore, carbocysteine improves steroid responsiveness and exerts anti-inflammatory activity. This analysis demonstrates that the use of carbocysteine in COPD patients represents a well-tolerated treatment with a favorable safety profile, and might contribute to a better quality of life for patients suffering from this serious illness.

Carbocysteine Modifies Circulating miR-21, IL-8, sRAGE, and fAGEs Levels in Mild Acute Exacerbated COPD Patients: A Pilot Study

Patients with Chronic Obstructive Pulmonary Disease (COPD) periodically experience acute exacerbation (AECOPD). Carbocysteine represents a valid add on therapy in COPD by exerting antioxidant and anti-inflammatory activities. The in vivo effects of carbocysteine on inflammatory markers are not yet fully understood. The aims of this study were to assess: (i) miR-21, IL-8, soluble Receptor for Advanced Glycation End Products (sRAGE), and fluorescent Advanced Glycation End Products (fAGEs) in control subjects (n = 9), stable (n = 9), and AECOPD patients (n = 24); and (ii) whether carbocysteine modifies these markers and the functional parameters in mild AECOPD patients. Mild AECOPD patients received or not carbocysteine along with background inhalation therapy for 20 days. At the onset and at the end of the observation period, the following parameters were evaluated: FEV1, FEF25–75%, CAT questionnaire; miR-21 by Real Time PCR; IL-8 and sRAGE by ELISA; and fAGEs by spectro-fluorescence method. COPD patients showed higher levels of miR-21, IL-8, fAGEs and lower levels of sRAGE compared to that of controls. miR-21 inversely correlated with FEV1. IL-8 and fAGEs were significantly different in stable and exacerbated COPD patients. Carbocysteine improved symptoms, FEV1 and FEF25–75%, increased sRAGE, and reduced miR-21, IL-8, and fAGEs in mild AECOPD patients. The present study provides compelling evidence that carbocysteine may help to manage mild AECOPD by downregulating some parameters of systemic inflammation.

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.

Antioxidants and Chronic Obstructive Pulmonary Disease

Antioxidants represent an attractive therapeutic avenue for individuals with chronic obstructive pulmonary disease (COPD). Cigarette smoke, the major cause of COPD, contains very high concentrations of gaseous and soluble oxidants that can directly induce cell injury and death. Furthermore, particulate matter in cigarette smoke activates lung macrophages that subsequently attract neutrophils. Both neutrophils and macrophages from the lungs of cigarette smokers continuously release large amounts of superoxide and hydrogen peroxide through the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. Once individuals with COPD stop smoking, the neutrophilic inflammation in the airways and lung parenchyma persists, as do the markers of oxidative stress. Several animal models of cigarette smoke-induced injury have provided evidence that various antioxidants may prevent inflammation and morphological changes associated with COPD however, evidence of benefit in patients is less abundant. Although oxidants can inactivate alpha-1 antitrypsin and other protective proteins, damage lung tissue, and increase mucus production, they also are essential for killing pathogens and resolving inflammation. This review will examine the pre-clinical and clinical evidence of a role for antioxidants in the therapy of patients with COPD.