Role of N-acetylcysteine in the management of COPD

Effects of N-acetylcysteine on hepatocellular carcinoma in chronic hepatitis C

Hepatitis C virus (HCV) infection significantly contributes to global hepatocellular carcinoma (HCC) incidence. N-Acetylcysteine (NAC), known for its antioxidant properties, is a potential therapeutic agent. However, evidence on its efficacy in reducing HCC risk among HCV patients is limited. A retrospective cohort analysis using Taiwan's National Health Insurance Research Database (2008-2018) included ≥18-year-old HCV patients. NAC usage (≥28 cumulative defined daily doses [cDDDs]) was assessed for its association with HCC risk using Cox regression models and propensity score matching. The study comprised 269,647 HCV patients, with detailed NAC dosage characterization and hazard ratios (HRs) for HCC risk. Post-matching, NAC usage emerged as the significant predictor of reduced HCC risk (adjusted HR: 0.39, 95% CI: 0.37-0.41, P<0.0001). Dose-response analysis showed reduced HCC risk with increasing cDDDs of NAC (P<0.0001). Higher daily NAC dosage (≥1 DDD) was associated with significantly lower HCC risk (adjusted HR: 0.33, 95% CI: 0.31-0.36, P<0.0001). The study provides compelling evidence for NAC's potential in reducing HCC risk among HCV patients. Insights into dose-dependent effects and optimal daily intensity thresholds offer valuable directions for future therapeutic strategies and clinical trials targeting HCC burden in HCV-infected individuals.

Protective effect of N-acetylcysteine against hepatocellular carcinoma in hepatitis B virus carriers

Hepatitis B virus (HBV) infection is a leading risk factor for hepatocellular carcinoma (HCC), contributing to cancer development through direct genomic integration and chronic inflammation. N-acetylcysteine (NAC), known for its antioxidant properties, is widely utilized in cancer prevention. However, clinical evidence regarding its protective effect against HCC in HBV carriers remains sparse. In this retrospective cohort study spanning 2008 to 2018, we utilized Taiwan's National Health Insurance Research Database (NHIRD) to include 1,061,174 chronic HBV carriers. Participants were stratified into NAC users and non-users using Propensity Score Matching. We assessed the incidence of HCC in both cohorts, examining the relationship between NAC usage duration and HCC incidence, and evaluating the dose-response effect. NAC users exhibited a significantly lower risk of developing HCC (adjusted hazard ratio [aHR]: 0.38; 95% confidence interval [CI]: 0.36-0.40; P < 0.0001). A dose-response relationship was evident, with higher cumulative defined daily doses (cDDDs) of NAC correlating with reduced HCC risk, revealing a significant trend (P < 0.0001). Notably, a daily NAC intensity of > 1.4 DDDs was associated with a decreased risk of HCC in HBV patients. Our results demonstrate that the use of NAC, in a dose-dependent manner, is intricately linked with a diminished incidence of HCC in individuals chronically infected with the HBV.

Applications and advancements of nanoparticle-based drug delivery in alleviating lung cancer and chronic obstructive pulmonary disease

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are among the leading causes of mortality worldwide. Cigarette smoking is among the main aetiologic factors for both ailments. These diseases share common pathogenetic mechanisms including inflammation, oxidative stress, and tissue remodelling. Current therapeutic approaches are limited by low efficacy and adverse effects. Consequentially, LC has a 5-year survival of < 20%, while COPD is incurable, underlining the necessity for innovative treatment strategies. Two promising emerging classes of therapy against these diseases include plant-derived molecules (phytoceuticals) and nucleic acid-based therapies. The clinical application of both is limited by issues including poor solubility, poor permeability, and, in the case of nucleic acids, susceptibility to enzymatic degradation, large size, and electrostatic charge density. Nanoparticle-based advanced drug delivery systems are currently being explored as flexible systems allowing to overcome these limitations. In this review, an updated summary of the most recent studies using nanoparticle-based advanced drug delivery systems to improve the delivery of nucleic acids and phytoceuticals for the treatment of LC and COPD is provided. This review highlights the enormous relevance of these delivery systems as tools that are set to facilitate the clinical application of novel categories of therapeutics with poor pharmacokinetic properties.

N-acetyl cysteine augments adipose tissue-derived stem cell efficacy on inflammatory markers and regulatory T cell system balance in an allergic asthma model

BACKGROUND

Allergic asthma is a destructive inflammatory process in the respiratory system. The anti-inflammatory and antioxidant effects of N-acetylcysteine (NAC) have been reported in patients with obstructive pulmonary disease. On the other hand, several studies have shown the modulatory effects of mesenchymal stem cells on the immune system and inflammatory responses. Accordingly, the purpose of the current study was to evaluate the effect of administration of adipose tissue-derived stem cells (ADSCs) plus NAC on regulatory T cell system balance in an allergic asthma model.

METHODS

Eighty Sprague- Dawley rats were randomly divided into the following groups: Control, Plasmalite, Allergic asthma, Allergic asthma + ADSCs, NAC, Allergic asthma + NAC, Allergic asthma + ADSCs + NAC and Allergic asthma + Prednisolone. at the end of the experiment, arterial blood gas analysis, inflammatory cell counts in bronchoalveolar lavage fluid (BALF), inflammatory cytokine concentration, total IgE and specific OVA-IgE levels, gene expression levels of CD4+-T cell subsets, pulmonary indicators, edema, and lung histopathology were evaluated in all groups.

RESULTS

Administration of NAC plus ADSCs demonstrated a significant decrease in total WBC and eosinophil counts, which was in line with remarkable decrease in IL-17 and TNF-α concentrations and increases in IL-10 level compared with other treated groups. NAC plus ADSC treatment showed significant increases in Treg gene expression, although Th17 and Th2 expression significantly decreased compared with that in prednisolone- treated rats.

CONCLUSION

The results of the present study documented that the administration of ADSCs plus NAC has an inhibitory effect on the inflammation caused by allergic asthma in a rat model. The improvement of inflammatory indexes was significantly higher than that with prednisolone treatment.

The efficacy of N-acetylcysteine in decreasing airway inflammation and mucus accumulation in horses with 18 hours of head confinement

BACKGROUND

During transportation many horses develop post-transportation infection, which can be life-threatening and end their sport career. Preventing mucus accumulation and inflammation during transportation is vital, emphasizing the need for effective strategies to enhance overall horse health welfare.

OBJECTIVES

Assess the impact of N-acetylcysteine (NAC) on mucus accumulation and inflammation in horses subjected to 18 hours of head confinement.

ANIMALS

Six healthy crossbred horses, 5.3 ± 2.1 years of age and weighing 387 ± 30 kg.

METHODS

Prospective placebo-controlled cross-over design study. The horses' heads were restrained in their stalls for a period of 18 hours. They were studied under 4 conditions: Not confined (NC): before head confinement, placebo (P), and confined head (CH): 18 hours of head confinement without treatment, and N-Acetylcysteine (NAC): 18 hours of head confinement treated with NAC before confinement (15 mg/kg/day NAC PO for 3 days). Bronchoalveolar lavage (BAL) was performed in each condition. Mucus accumulation along the trachea was evaluated by endoscopy.

RESULTS

Endoscopic scores were significantly different between CH and other conditions, whereas no significant differences were found among NC, P, and NAC. The BAL cell count (34 291 ± 2624 cells/μL), neutrophil and lymphocyte count (18 601 ± 3193 cells/μL and 3337.4 ± 593 cells/μL, respectively) in CH were significantly higher compared to NAC. Neutrophil percentage was significantly higher in CH (53.8 ± 8%) compared to horses that received NAC (20.08 ± 8%). Conversely, in comparison to NAC (66.33 ± 9%), the percentage of macrophages was significantly lower in CH (35.7 ± 10%).

CONCLUSIONS

N-acetylcysteine was found to significantly decrease mucus accumulation and inflammatory cell counts in horses with head confinement.

From treatable traits to GETomics in airway disease: moving towards clinical practice

The treatable traits approach represents a strategy for patient management. It is based on the identification of characteristics susceptible to treatments or predictive of treatment response in each individual patient. With the objective of accelerating progress in research and clinical practice relating to such a treatable traits approach, the Portraits event was convened in Barcelona, Spain, in November 2022. Here, while reporting the key concepts that emerged from the discussions during the meeting, we review the current state of the art related to treatable traits and chronic respiratory diseases management, and we describe the possible actions that clinicians can take in clinical practice to implement the treatable traits framework. Furthermore, we explore the new concept of GETomics and the new models of research in the field of COPD.

Potential of Nano-Antioxidants and Nanomedicine for Recovery from Neurological Disorders Linked to Long COVID Syndrome

Long-term neurological complications, persisting in patients who cannot fully recover several months after severe SARS-CoV-2 coronavirus infection, are referred to as neurological sequelae of the long COVID syndrome. Among the numerous clinical post-acute COVID-19 symptoms, neurological and psychiatric manifestations comprise prolonged fatigue, "brain fog", memory deficits, headache, ageusia, anosmia, myalgias, cognitive impairments, anxiety, and depression lasting several months. Considering that neurons are highly vulnerable to inflammatory and oxidative stress damages following the overproduction of reactive oxygen species (ROS), neuroinflammation and oxidative stress have been suggested to dominate the pathophysiological mechanisms of the long COVID syndrome. It is emphasized that mitochondrial dysfunction and oxidative stress damages are crucial for the pathogenesis of neurodegenerative disorders. Importantly, antioxidant therapies have the potential to slow down and prevent disease progression. However, many antioxidant compounds display low bioavailability, instability, and transport to targeted tissues, limiting their clinical applications. Various nanocarrier types, e.g., liposomes, cubosomes, solid lipid nanoparticles, micelles, dendrimers, carbon-based nanostructures, nanoceria, and other inorganic nanoparticles, can be employed to enhance antioxidant bioavailability. Here, we highlight the potential of phytochemical antioxidants and other neuroprotective agents (curcumin, quercetin, vitamins C, E and D, melatonin, rosmarinic acid, N-acetylcysteine, and Ginkgo Biloba derivatives) in therapeutic strategies for neuroregeneration. A particular focus is given to the beneficial role of nanoparticle-mediated drug-delivery systems in addressing the challenges of antioxidants for managing and preventing neurological disorders as factors of long COVID sequelae.

Impact of N-Acetyl Cysteine (NAC) on Tuberculosis (TB) Patients-A Systematic Review

Sustained TB infection overproduces reactive oxygen species (ROS) as a host defense mechanism. Research shows ROS is destructive to lung tissue. Glutathione (GSH) neutralizes ROS, although it is consumed. NAC is a precursor of GSH synthesis, and administering an appropriate dose of NAC to patients with respiratory conditions may enhance lung recovery and replenish GSH. The present review searched for articles reporting on the effects of NAC in TB treatment from 1960 to 31 May 2022. The PICO search strategy was used in Google Scholar, PubMed, SciFinder, and Wiley online library databases. The COVIDENCE tool was used to delete inappropriate content. We eventually discovered five clinical trials, one case report, seven reviews, in vitro research, and four experimental animal studies from the twenty-four accepted articles. The use of NAC resulted in increased GSH levels, decreased treatment time, and was safe with minimal adverse events. However, the evidence is currently insufficient to estimate the overall effects of NAC, thus the study warrants more NAC clinical trials to demonstrate its effects in TB treatment.

Drug Utilization and Potential Drug-Drug Interactions within an Intensive Care Unit at a University Tertiary Care Hospital in Egypt

There are few reports on drug utilization and drug-drug interactions in Intensive Care Units (ICUs) in Egypt. A total of 94 patients participated in this retrospective observational study. Patient's medical records were used to collect demographics, medical history, admission and discharge dates and medications used. The mean ± SD of the Glasgow Coma Scale (GCS) scores was 9.9 ± 4.4 and the median length of stay was 7 days (range 1-47 days). The total number of prescribed medications ranged from 4-29 with a mean ± SD of 14.1 ± 5.5 medications per patient. The top three most prescribed categories belonged to (1) anti-infective agents (23.9%); (2) electrolyte, caloric and water balance agents (14.6%); and (3) blood formation, coagulation and thrombosis (11.3%). The proton pump inhibitor, esomeprazole, was the most frequently prescribed medication accounting for 6.5% of total prescriptions, followed by clindamycin and magnesium sulfate each accounting for 3.5% of total prescriptions. The potential Drug-Drug Interactions (pDDIs) showed a total of 968 pDDIs with a mean ± SD (range) of 10.2 ± 9.4 (0-43) pDDIs per patient: severe (contraindicated) (3), major (178), moderate (618) and minor (169). Overall, the drug utilization patterns in this study were consistent with ICU drug utilization from other countries in the region. The implementation of clinical decision support systems and the involvement of clinical pharmacists may help improve medication safety.

Efficacy of N-acetylcysteine on idiopathic or postinfective non-cystic fibrosis bronchiectasis: a systematic review and meta-analysis protocol

INTRODUCTION

Non-cystic fibrosis (non-CF) bronchiectasis is a chronic pulmonary disorder that causes destruction and permanent dilatation of the airways, resulting in excessive sputum production, repeated infection and inflammation. A need for high-quality and specialised care has been highlighted in recent years. N-acetylcysteine (NAC) is a widely used mucolytic agent in respiratory diseases that not only possesses a property to enhance secretion clearance, but also exhibits antioxidant and anti-inflammatory effects. However, the efficacy and safety of NAC are not well described in idiopathic or postinfective non-CF bronchiectasis.

OBJECTIVE

This study aims to evaluate the efficacy and safety of NAC in patients with idiopathic or postinfective non-CF bronchiectasis.

METHODS AND ANALYSIS

PubMed/Medline, Embase, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials will be searched from inception to 1 March 2022 for eligible randomised controlled trials that investigating the effects of NAC on exacerbations, health-related quality of life, lung functions, sputum volume and colour, inflammation markers, exercise capacity and adverse events in patients with idiopathic or postinfective non-CF bronchiectasis, with ongoing trials being identified by searches on the websites of Chinese Clinical Trial Registry and ClinicalTrials.gov. Two independent reviewers will identify eligible studies, two will fulfil the data extraction and three will perform the quality appraisal. To generate more accurate analyses, the Grading of Recommendations Assessment, Development and Evaluation will be used to grade the evidence. χ² test and I² statistic will be used to assess heterogeneity. Subgroup analyses and meta-regression will be used to explore potential sources of heterogeneity. The potential publication bias will be examined using funnel plots.

ETHICS AND DISSEMINATION

No research ethics approval is required in this study because it is a systematic review. The results of this study are expected to be disseminated through peer-reviewed journals and conferences.

TRIAL REGISTRATION NUMBER

CRD42021239438.

Complexity of NAC Action as an Antidiabetic Agent: Opposing Effects of Oxidative and Reductive Stress on Insulin Secretion and Insulin Signaling

Dysregulated redox balance is involved in the pathogenesis of type 2 diabetes. While the benefit of antioxidants in neutralizing oxidative stress is well characterized, the potential harm of antioxidant-induced reductive stress is unclear. The aim of this study was to investigate the dose-dependent effects of the antioxidant N-acetylcysteine (NAC) on various tissues involved in the regulation of blood glucose and the mechanisms underlying its functions. H₂O₂ was used as an oxidizing agent in order to compare the outcomes of oxidative and reductive stress on cellular function. Cellular death in pancreatic islets and diminished insulin secretion were facilitated by H₂O₂-induced oxidative stress but not by NAC. On the other hand, myotubes and adipocytes were negatively affected by NAC-induced reductive stress, as demonstrated by the impaired transmission of insulin signaling and glucose transport, as opposed to H₂O₂-stimulatory action. This was accompanied by redox balance alteration and thiol modifications of proteins. The NAC-induced deterioration of insulin signaling was also observed in healthy mice, while both insulin secretion and insulin signaling were improved in diabetic mice. This study establishes the tissue-specific effects of NAC and the importance of the delicate maintenance of redox balance, emphasizing the challenge of implementing antioxidant therapy in the clinic.

COVID-19 Pandemic: What Considerations Should Be Taken during the Assessment and Management of COPD Exacerbation?

The on-going coronavirus disease 2019 (COVID-19) pandemic could contribute to higher mortality in population with underlying respiratory diseases, including chronic obstructive pulmonary disease (COPD). The aim of this review was to inform readers pertaining to the correlation of COPD exacerbation and severe acute respiratory syndrome-2 (SARS-CoV-2) infection along with considerations that could be taken in the clinical diagnosis and management. The literature search was conducted on Google Scholar, Scopus, and PubMed databases using related terms (such as, but not limited to, “COVID-19,” “SARS-CoV-2,” “COPD management,” “N-acetylcysteine,” and “corticosteroids”) on November 1–9, 2021. Recent studies suggest that COVID-19 and COPD are correlated through three pathways, namely, angiotensin-converting enzyme 2 expression, dysregulation of biological parameters, and occurrence of pneumonia. Early detection of COVID-19 in patients with underlying COPD is difficult because they share similar symptoms, attributed to advanced progression of the infection and subsequently deteriorates lung function. During COPD management, clinicians are expected to take consideration on the effect of systemic corticosteroids if patients develop COVID-19. In conclusion, COVID-19 and COPD and its management are potentially correlated, contributing to the worsening of the disease. There is a need of immediate research to reveal the true correlation between COVID-19 and COPD to improve the management.

Curcumin and n-acetylcysteine cocrystal produced with supercritical solvent: characterization, solubility, and preclinical evaluation of antinociceptive and anti-inflammatory activities

Curcumin presents a promising anti-inflammatory potential, but its low water-solubility and bioavailability hinder its application. In this sense, cocrystallization represents a tool for improving physicochemical properties, solubility, permeability, and bioavailability of new drug candidates. Thus, the aim of this work was to produce curcumin cocrystals (with n-acetylcysteine as coformer, which possesses anti-inflammatory and antioxidant activities), by the anti-solvent gas technique using supercritical carbon dioxide, and to test its antinociceptive and anti-inflammatory potential. The cocrystal was characterized by differential scanning calorimetry, powder X-ray diffraction and scanning electron microscopy. The cocrystal solubility and antichemotaxic activity were also assessed in vitro. Antinociceptive and anti-inflammatory activities were carried out in vivo using the acetic acid-induced abdominal writhing and carrageenan-induced paw oedema assays in mice. The results demonstrated the formation of a new crystalline structure, thereby confirming the successful formation of the cocrystal. The higher solubility of the cocrystal compared to pure curcumin was verified in acidic and neutral pH, and the cocrystal inhibited the chemotaxis of neutrophils in vitro. In vivo assays showed that cocrystal presents increased antinociceptive and anti-inflammatory potency when compared to pure curcumin, which could be related to an improvement in its bioavailability.

N-Acetylcysteine (NAC) Inhibits Synthesis of IL-18 in Macrophage by Suppressing NLRP3 Expression to Reduce the Production of IFN-γ from NK Cells

Background

N-Acetylcysteine (NAC) had exerted antioxidation and anti-inflammation effects on chronic obstructive pulmonary disease (COPD) patients. However, its effect in regulating interleukin- (IL-) 18 was not fully understood. This study was designed to evaluate the specific mechanism of NAC regulating IL-18.

Materials and Methods

A total of 112 COPD patients and 103 health individuals were recruited in the study. Cytokine level in patients' serum was measured by enzyme-linked immunosorbent assay (ELISA). A COPD mouse model was established by administration of lipopolysaccharide (LPS) and cigarette smoke. The expression of cytokines was measured by ELISA and flow cytometry. Inflammasome-related protein was measured by Western blot.

Result

NAC could effectively improve the immune status of COPD patients as well as the COPD mouse model by downregulating proinflammation and inflammation cytokines including IL-1β, interferon- (IFN-) γ, tumor necrosis factor- (TNF-) α, and IL-18. It also had the capability to suppress synthesis of IL-18 in macrophage to inhibit the secretion of IFN-γ from natural killer (NK) cells through influencing the inflammasome-related protein in macrophages.

Conclusion

NAC could effectively inhibit the production of IL-18 by suppressing NLRP3 expression in macrophages to reduce the production of IFN-γ in NK cells.

The Next Generation of Molecular and Cellular Therapeutics for Inherited Retinal Disease

Inherited retinal degenerations (IRDs) are a diverse group of conditions that are often characterized by the loss of photoreceptors and blindness. Recent innovations in molecular biology and genomics have allowed us to identify the causative defects behind these dystrophies and to design therapeutics that target specific mechanisms of retinal disease. Recently, the FDA approved the first in vivo gene therapy for one of these hereditary blinding conditions. Current clinical trials are exploring new therapies that could provide treatment for a growing number of retinal dystrophies. While the field has had early success with gene augmentation strategies for treating retinal disease based on loss-of-function mutations, many novel approaches hold the promise of offering therapies that span the full spectrum of causative mutations and mechanisms. Here, we provide a comprehensive review of the approaches currently in development including a discussion of retinal neuroprotection, gene therapies (gene augmentation, gene editing, RNA modification, optogenetics), and regenerative stem or precursor cell-based therapies. Our review focuses on technologies that are being developed for clinical translation or are in active clinical trials and discusses the advantages and limitations for each approach.

Effect of N-Acetylcysteine Administration on 30-Day Mortality in Critically Ill Patients with Septic Shock Caused by Carbapenem-Resistant Klebsiella pneumoniae and Acinetobacter baumannii: A Retrospective Case-Control Study

Carbapenem-resistant Klebsiella pneumoniae (CR-Kp) and Acinetobacter baumannii (CR-Ab) represent important cause of severe infections in intensive care unit (ICU) patients. N-Acetylcysteine (NAC) is a mucolytic agent with antioxidant and anti-inflammatory properties, showing also in-vitro antibacterial activity. Aim was to evaluate the effect on 30-day mortality of the addition of intravenous NAC to antibiotics in ICU patients with CR-Kp or CR-Ab septic shock. A retrospective, observational case:control study (1:2) in patients with septic shock caused by CR-Kp or CR-Ab hospitalized in two different ICUs was conducted. Cases included patients receiving NAC plus antimicrobials, controls included patients not receiving NAC. Cases and controls were matched for age, SAPS II, causative agent and source of infection. No differences in age, sex, SAPS II score or time to initiate definitive therapy were observed between cases and controls. Pneumonia and bacteremia were the leading infections. Overall, mortality was 48.9% (33.3% vs. 56.7% in cases and controls, p = 0.05). Independent risk factors for mortality were not receiving NAC (p = 0.002) and CR-Ab (p = 0.034) whereas therapy with two in-vitro active antibiotics (p = 0.014) and time to initial definite therapy (p = 0.026) were protective. NAC plus antibiotics might reduce the 30-day mortality rate in ICU patients with CR-Kp and CR-Ab septic shock.

Targeting of Mammalian Glycans Enhances Phage Predation in the Gastrointestinal Tract

The human gastrointestinal mucosal surface consists of a eukaryotic epithelium, a prokaryotic microbiota, and a carbohydrate-rich interface that separates them. In the gastrointestinal tract, the interaction of bacteriophages (phages) and their prokaryotic hosts influences the health of the mammalian host, especially colonization with invasive pathobionts. Antibiotics may be used, but they also kill protective commensals. Here, we report a novel phage whose lytic cycle is enhanced in intestinal environments. The tail fiber gene, whose protein product binds human heparan sulfated proteoglycans and localizes the phage to the epithelial cell surface, positions it near its bacterial host, a type of locational targeting mechanism. This finding offers the prospect of developing mucosal targeting phage to selectively remove invasive pathobiont species from mucosal surfaces.IMPORTANCE Invasive pathobionts or microbes capable of causing disease can reside deep within the mucosal epithelium of our gastrointestinal tract. Targeted effective antibacterial therapies are needed to combat these disease-causing organisms, many of which may be multidrug resistant. Here, we isolated a lytic bacteriophage (phage) that can localize to the epithelial surface by binding heparan sulfated glycans, positioning it near its host, Escherichia coli This targeted therapy can be used to selectively remove invasive pathobionts from the gastrointestinal tract, preventing the development of disease.

An insight on safety, efficacy, and molecular docking study reports of N-acetylcysteine and its compound formulations

N-acetylcysteine (NAC) is considered as the body's major antioxidant molecules with diverse biological properties. In this review, the pharmacokinetics, safety and efficacy report on both the preclinical and clinical summary of NAC is discussed. Both in vitro and in vivo preclinical studies along with the clinical data have shown that NAC has enormous biological properties. NAC is used in the treatment of acetaminophen poisoning, diabetic nephropathy, Alzheimer's disease, schizophrenia, and ulcerative colitis, etc. Numerous analytical techniques, for instance, UPLC, LC-MS, HPLC, RP-IPC are primarily employed for the estimation of NAC in different single and fixed-dose combinations. The molecular docking studies on NAC demonstrate the binding within Sudlow's site-I hydrogen bonds and formation of NAC and BSA complexes. Various hydrophobic and hydrophilic amino acids generally exist in making contact with NAC as NAC-BSA complexes. Docking studies of NAC with the active site of the urease exposed an O-coordinated bond through nickel 3002 and a hydrogen bond through His-138. NAC and its analogs also made the allosteric pockets that helped to describe almost all favorable pose for the chaperone in a complex through the protein. Thus, we intended to highlight the several health benefits of this antioxidant compound and applications in pharmaceutical product development.

Evidence-based management of acute rhinosinusitis with herbal products

Background

The overuse of antibiotics for unjustified indications such as the management of acute uncomplicated rhinosinusitis has contributed to the emergence of antibiotic-resistant strains of bacteria and prompted the need for alternative treatments. This review assesses the quality of evidence for the management of acute rhinosinusitis with herbal products, with the goal of positioning them among other treatments and identifying future research directions. The MEDLINE database was searched for randomized controlled trials with Sinupret®, Pelargonium sidoides extract, Cyclamen europaeum (CE), cineole, and GeloMyrtol®. Searches with N-acetylcysteine and mometasone furoate nasal spray (MFNS) were performed to compare the strength of evidence of herbal products to these conventional products, which are indicated for acute rhinosinusitis.

Main body

Evidence was strongest for Sinupret, followed by Pelargonium sidoides extract. Their use in acute rhinosinusitis is supported by randomized placebo-controlled trials demonstrating both clinical efficacy and safety. Comparative data with conventional treatments such as topical glucocorticosteroids were found only for Sinupret and suggested comparable efficacy in a small study.

For other herbal products, the overall level of evidence was low. The search retrieved two small-scale placebo-controlled randomized studies with CE nasal spray. The two trials were not powered to draw conclusions about the safety and efficacy of CE nasal spray and reported a lack of efficacy with CE on symptom reduction. Only one randomized placebo-controlled trial was identified for GeloMyrtol and cineole. These suggested an improvement in acute rhinosinusitis symptoms with both products, but the results warrant replication in larger trials.

Studies directly comparing herbal products are scarce; one randomized trial has compared cineole with Sinupret, but the results need confirmation in further studies.

Studies with N-acetylcysteine are limited to small-scale clinical trials, while MFNS is supported by a strength of evidence comparable to Sinupret in this indication.

Conclusion

State-of-the-art studies demonstrating the efficacy and safety of herbal products for the management of acute rhinosinusitis are available. Given that the evidence for Sinupret is the strongest and comparable to that of a widely available topical corticosteroid, MFNS, Sinupret may be considered for the management of acute uncomplicated rhinosinusitis.

N-Acetyl cysteine abrogates silver-induced reactive oxygen species in human cells without altering silver-based antimicrobial activity

Silver-based antimicrobials are widely used topically to treat infections associated with multi-drug resistant (MDR) pathogens. Expanding this topical use to aerosols to treat lung infections requires understanding and preventing silver toxicity in the respiratory tract. A key mechanism resulting in silver-induced toxicity is the production of reactive oxygen species (ROS). In this study, we have verified ROS generation in silver-treated bronchial epithelial cells prompting evaluation of three antioxidants, N-acetyl cysteine (NAC), ascorbic acid, and melatonin, to identify potential prophylactic agents. Among them, NAC was the only candidate that abrogated the ROS generation in response to silver acetate exposure resulting in the rescue of these cells from silver-associated toxicity. Further, this protective effect directly translated to preservation of metabolic activity, as demonstrated by the normal levels of citric acid cycle metabolites in NAC-pretreated silver acetate-exposed cells. Because the citric acid cycle remained functional, silver-exposed cells pre-incubated with NAC demonstrated significantly higher levels of adenosine triphosphate levels compared with NAC-free controls. Moreover, we found that this prodigious capacity of NAC to rescue silver acetate-exposed cells was due not only to its antioxidant activity, but also to its ability to directly bind silver. Despite binding to silver, NAC did not alter the antimicrobial activity of silver acetate.

Potential Anti-SARS-CoV-2 Therapeutics That Target the Post-Entry Stages of the Viral Life Cycle: A Comprehensive Review

The coronavirus disease-2019 (COVID-19) pandemic continues to challenge health care systems around the world. Scientists and pharmaceutical companies have promptly responded by advancing potential therapeutics into clinical trials at an exponential rate. Initial encouraging results have been realized using remdesivir and dexamethasone. Yet, the research continues so as to identify better clinically relevant therapeutics that act either as prophylactics to prevent the infection or as treatments to limit the severity of COVID-19 and substantially decrease the mortality rate. Previously, we reviewed the potential therapeutics in clinical trials that block the early stage of the viral life cycle. In this review, we summarize potential anti-COVID-19 therapeutics that block/inhibit the post-entry stages of the viral life cycle. The review presents not only the chemical structures and mechanisms of the potential therapeutics under clinical investigation, i.e., listed in clinicaltrials.gov, but it also describes the relevant results of clinical trials. Their anti-inflammatory/immune-modulatory effects are also described. The reviewed therapeutics include small molecules, polypeptides, and monoclonal antibodies. At the molecular level, the therapeutics target viral proteins or processes that facilitate the post-entry stages of the viral infection. Frequent targets are the viral RNA-dependent RNA polymerase (RdRp) and the viral proteases such as papain-like protease (PLpro) and main protease (Mpro). Overall, we aim at presenting up-to-date details of anti-COVID-19 therapeutics so as to catalyze their potential effective use in fighting the pandemic.

Protective Role of Glutathione and Nitric Oxide Production in the Pathogenesis of Pterygium

Objective

In the pathogenesis of pterygium, the protective role of glutathione and nitric oxide production is unclear. These are important factors for homeostasis in the redox state of cells. The aim of this study was to determine the levels of these and related parameters in pterygium tissue. Patients and Methods. The study sample consisted of 120 patients diagnosed with primary or recurrent pterygium. Five groups of tissue samples were examined: control, primary pterygium, recurrent pterygium, and two groups of primary pterygium given a one-month NAC presurgery treatment (topical or systemic). The levels of endothelial nitric oxide synthase (eNOS), nitric oxide (NO), 3-nitrotyrosine (3NT), reduced and oxidized glutathione (GSH and GSSG), and catalase (CAT) were evaluated in tissue homogenates.

Results

Compared with the control, decreased levels of eNOS, NO, and 3-nitrotyrosine as well as the degree of oxidation of GSH (GSSG%) were observed in primary and recurrent pterygium. 3-Nitrotyrosine and GSSG% were reduced in the other pterygium groups. GSH and CAT were enhanced in recurrent pterygium and systemic-treated primary pterygium but were unchanged for topical-treated primary pterygium. There was a strong positive correlation of eNOS with NO and 3NT, GSSG% with NO and 3NT, and GSH with GSSG and CAT. Women showed a higher level of GSH and catalase in primary pterygium, whereas a lower level of GSH and a higher level of NO in recurrent pterygium.

Conclusion

The results are congruent with the following proposed sequence of events leading to a protective response of the organism during the pathogenesis of primary pterygium: a decreased level of eNOS provokes a decline in the level of NO in pterygium tissue, which then leads to reduced S-nitrosylation of GSH or other thiols and possibly to the modulation of the intracellular level of GSH through synthesis and/or mobilization from other tissues.

Conventional and Nanotechnology Based Approaches to Combat Chronic Obstructive Pulmonary Disease: Implications for Chronic Airway Diseases

Chronic obstructive pulmonary disease (COPD) is the most prevalent obstructive lung disease worldwide characterized by decline in lung function. It is associated with airway obstruction, oxidative stress, chronic inflammation, mucus hypersecretion, and enhanced autophagy and cellular senescence. Cigarette smoke being the major risk factor, other secondary risk factors such as the exposure to air pollutants, occupational exposure to gases and fumes in developing countries, also contribute to the pathogenesis of COPD. Conventional therapeutic strategies of COPD are based on anti-oxidant and anti-inflammatory drugs. However, traditional anti-oxidant pharmacological therapies are commonly used to alleviate the impact of COPD as they have many associated repercussions such as low diffusion rate and inappropriate drug pharmacokinetics. Recent advances in nanotechnology and stem cell research have shed new light on the current treatment of chronic airway disease. This review is focused on some of the anti-oxidant therapies currently used in the treatment and management of COPD with more emphasis on the recent advances in nanotechnology-based therapeutics including stem cell and gene therapy approaches for the treatment of chronic airway disease such as COPD and asthma.

Drug ReposER: a web server for predicting similar amino acid arrangements to known drug binding interfaces for potential drug repositioning

A common drug repositioning strategy is the re-application of an existing drug to address alternative targets. A crucial aspect to enable such repurposing is that the drug's binding site on the original target is similar to that on the alternative target. Based on the assumption that proteins with similar binding sites may bind to similar drugs, the 3D substructure similarity data can be used to identify similar sites in other proteins that are not known targets. The Drug ReposER (DRug REPOSitioning Exploration Resource) web server is designed to identify potential targets for drug repurposing based on sub-structural similarity to the binding interfaces of known drug binding sites. The application has pre-computed amino acid arrangements from protein structures in the Protein Data Bank that are similar to the 3D arrangements of known drug binding sites thus allowing users to explore them as alternative targets. Users can annotate new structures for sites that are similarly arranged to the residues found in known drug binding interfaces. The search results are presented as mappings of matched sidechain superpositions. The results of the searches can be visualized using an integrated NGL viewer. The Drug ReposER server has no access restrictions and is available at http://mfrlab.org/drugreposer/.

N-acetylcysteine Decreases Fibrosis and Increases Force-Generating Capacity of mdx Diaphragm

Respiratory muscle weakness occurs due to dystrophin deficiency in Duchenne muscular dystrophy (DMD). The mdx mouse model of DMD shows evidence of impaired respiratory muscle performance with attendant inflammation and oxidative stress. We examined the effects of N-acetylcysteine (NAC) supplementation on respiratory system performance in mdx mice. Eight-week-old male wild type (n = 10) and mdx (n = 20) mice were studied; a subset of mdx (n = 10) received 1% NAC in the drinking water for 14 days. We assessed breathing, diaphragm, and external intercostal electromyogram (EMG) activities and inspiratory pressure during ventilatory and non-ventilatory behaviours. Diaphragm muscle structure and function, cytokine concentrations, glutathione status, and mRNA expression were determined. Diaphragm force-generating capacity was impaired in mdx compared with wild type. Diaphragm muscle remodelling was observed in mdx, characterized by increased muscle fibrosis, immune cell infiltration, and central myonucleation. NAC supplementation rescued mdx diaphragm function. Collagen content and immune cell infiltration were decreased in mdx + NAC compared with mdx diaphragms. The cytokines IL-1β, IL-6 and KC/GRO were increased in mdx plasma and diaphragm compared with wild type; NAC decreased systemic IL-1β and KC/GRO concentrations in mdx mice. We reveal that NAC treatment improved mdx diaphragm force-generating capacity associated with beneficial anti-inflammatory and anti-fibrotic effects. These data support the potential use of NAC as an adjunctive therapy in human dystrophinopathies.

Therapeutic options to treat mustard gas poisoning - Review

Among the blistering (vesicant) chemical warfare agents (CWA), sulfur mustard is the most important since it is known as the "King of chemical warfare agents". The use of sulfur mustard has caused serious damages in several organs, especially the eyes, skin, respiratory, central and peripheral nervous systems after short and long term exposure, incapacitating and even killing people and troops. In this review, chemical properties, mechanism of actions and their effects on each organ, clinical manifestations, diagnostic evaluation of the actions triage, and treatment of injuries have been described.

N-acetylcysteine improves oxidative stress and inflammatory response in patients with community acquired pneumonia: A randomized controlled trial

Oxidative stress is considered to be part of the pathogenic mechanism for community-acquired pneumonia (CAP) and is closely linked to inflammation. Attenuation of oxidative stress would be expected to reduce pulmonary damage. Antioxidants have been found to be effective in alleviating lung injury and protecting against damage of other organs.The aim of the study was to compare the effect of adding N-acetylcysteine (NAC) to conventional treatment versus conventional treatment on oxidative stress, inflammatory factors, and radiological changes in CAP patients.Eligible CAP patients at Weihai Municipal Hospital were stratified and randomly assigned to either NAC group or non-NAC group between August 2016 and March 2017. The NAC group received conventional treatment for pneumonia and NAC (1200 mg/d). Thenon-NAC group received conventional therapy. malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant capacity (TAOC), tumor necrosis factor-α (TNF-α), and computed tomography (CT) images were evaluated at baseline and after treatment. The primary endpoint indicators were the changes in oxidative stress parameters (MDA, TAOC, SOD) and TNF-α after treatment in the NAC group compared with those in the non-NAC group. The secondary endpoint indicator was any difference in CT scores after treatment in the NAC group compared with the non-NAC group.Baseline levels of MDA, TAOC, SOD, and TNF-α were similar between the 2 groups before treatment. Plasma levels of MDA and TNF-α decreased more (P < .05 MDA:p 0.004, TNF-α:p <0.001) in the NAC group than the non-NAC group, and there was a reliable increase in TAOC content (p 0.005). There was no significant difference in increased plasma SOD activity between the groups (p 0.368), and the NAC group did not show a greater improvement from CT scores. No NAC-related adverse effects were observed.Addition of NAC therapy for CAP patients reduced MDA and TNF-α and increased TAOC. Treatment with NAC may help to reduce oxidative and inflammatory damage in pneumonia patients.

A Novel Compound, "FA-1" Isolated from Prunus mume, Protects Human Bronchial Epithelial Cells and Keratinocytes from Cigarette Smoke Extract-Induced Damage

Extract of the Japanese apricot (JAE) has biological properties as an antioxidant and anti-inflammatory agent. We hypothesized that JAE might exert therapeutic effects on cigarette smoke (CS)-induced DNA damage and cytotoxicity. In this study, we found that concentrated JAE protects against cigarette smoke extract (CSE)-induced cytotoxicity and DNA damage accompanied by increased levels of aldehyde dehydrogenase (ALDH)2, 3A1, and Werner's syndrome protein (WRN) in immortalized human bronchial epithelial cells (HBEC2) and normal human epidermal keratinocytes (NHEK). Using the centrifugal partition chromatography (CPC) method, we identified an undescribed compound, 5-hydroxymethyl-2-furaldehyde bis(5-formylfurfuryl) acetal (which we named FA-1), responsible for the protective effects against CSE. This chemical structure has not been reported from a natural source to date. Protective effects of isolated FA-1 against CSE were observed in both HBEC2 and NHEK cells. The studies described herein suggest that FA-1 isolated from JAE protects against CSE-induced DNA damage and apoptosis by augmenting multiple isozymes of ALDH and DNA repair and reducing oxidative stress.

N-acetyl cysteine reverts the proinflammatory state induced by cigarette smoke extract in lung Calu-3 cells

Chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF) are lethal pulmonary diseases. Cigarette consumption is the main cause for development of COPD, while CF is produced by mutations in the CFTR gene. Although these diseases have a different etiology, both share a CFTR activity impairment and proinflammatory state even under sterile conditions. The aim of this work was to study the extent of the protective effect of the antioxidant N-acetylcysteine (NAC) over the proinflammatory state (IL-6 and IL-8), oxidative stress (reactive oxygen species, ROS), and CFTR levels, caused by Cigarette Smoke Extract (CSE) in Calu-3 airway epithelial cells. CSE treatment (100 µg/ml during 24 h) decreased CFTR mRNA expression and activity, and increased the release of IL-6 and IL-8. The effect on these cytokines was inhibited by N-acetyl cysteine (NAC, 5 mM) or the NF-kB inhibitor, IKK-2 (10 µM). CSE treatment also increased cellular and mitochondrial ROS levels. The cellular ROS levels were normalized to control values by NAC treatment, although significant effects on mitochondrial ROS levels were observed only at short times (5´) and effects on CFTR levels were not observed. In addition, CSE reduced the mitochondrial NADH-cytochrome c oxidoreductase (mCx I-III) activity, an effect that was not reverted by NAC. The reduced CFTR expression and the mitochondrial damage induced by CSE could not be normalized by NAC treatment, evidencing the need for a more specific reagent. In conclusion, CSE causes a sterile proinflammatory state and mitochondrial damage in Calu-3 cells that was partially recovered by NAC treatment.

Effect of adjunctive use of systemic antioxidant therapy (N-acetylcysteine) on soluble receptor activator nuclear factor κB ligand levels in gingival crevicular fluid following surgical periodontal treatment for chronic periodontitis

N-acetylcysteine (NAC) is an anti-oxidant drug that has been used as a mucolytic agent and a paracetamol antidote for many years. This study was designed to determine the efficacy of the adjunctive use of NAC for periodontal treatment. Thirty subjects with moderate-to-severe chronic periodontitis were randomized to surgery with NAC (600 mg; S-NAC), surgery only (S-nonNAC), and healthy control groups. Gingival crevicular fluid (GCF) samples were obtained from all patients and sRANKL levels were determined by enzyme-linked immunosorbent assay at baseline, and 1, 3, and 7 months post-surgery. Plaque and gingival indices, probing depths, and clinical attachment levels were recorded at the same time. There was a significant reduction in probing depth at 3 months in the S-NAC group when compared to the S-nonNAC group (P < 0.05). However, no statistically significant differences in plaque and gingival indices, probing depths, clinical attachment levels, and sRANKL levels in GCF were noted between the surgical treatment groups at the end of 7 months. Hence, the use of adjunctive NAC resulted in a significant reduction in probing depths in the S-NAC group when compared to the S-nonNAC group at 3 months, but no statistically significant differences in GCF sRANKL levels were observed in the sites that underwent surgical treatment with or without NAC at different time intervals.

Effects of N-acetylcysteine on First-Line Sequential Therapy for Helicobacter pylori Infection: A Randomized Controlled Pilot Trial

Background/Aims

To evaluate the adjuvant effects of N-acetylcysteine (NAC) on first-line sequential therapy (SQT) for Helicobacter pylori infection.

Methods

Patients with H. pylori infections were randomly assigned to receive sequential therapy with (SQT+NAC group, n=49) or without (SQT-only group, n=50) NAC. Sequential therapy consisted of rabeprazole 20 mg and amoxicillin 1 g for the first 5 days, followed by rabeprazole 20 mg, clarithromycin 500 mg and metronidazole 500 mg for the remaining 5 days; all drugs were administered twice daily. For the SQT+NAC group, NAC 400 mg bid was added for the first 5 days of sequential therapy. H. pylori eradication was evaluated 4 weeks after the completion of therapy.

Results

The eradication rates by intention-to-treat analysis were 58.0% in the SQT-only group and 67.3% in the SQT+NAC group (p=0.336). The eradication rates by per-protocol analysis were 70.0% in the SQT-only group and 80.5% in the SQT+NAC group (p=0.274). Compliance was very good in both groups (SQT only/SQT+NAC groups: 95.2%/100%, p=0.494). There was no significant difference in the adverse event rates between groups (SQT-only/SQT+NAC groups: 26.2%/26.8%, p=0.947).

Conclusions

The H. pylori eradication rate was numerically higher in the SQT+NAC group than in the SQT-only group. As our data did not reach statistical significance, larger trials are warranted.

Oxidative Stress: A Potential Therapeutic Target in Placental Malaria

Placental malaria, characterized by sequestration of Plasmodium falciparum in the maternal placental blood space and associated inflammatory damage, contributes to poor birth outcomes and ~200,000 infant deaths annually. Specific mechanisms that contribute to placental damage and dysfunction during malaria are not completely understood. To investigate a potential role for oxidative stress, antioxidant genes and markers for oxidative damage were assessed by quantitative PCR and immunohistochemistry in Plasmodium chabaudi AS-infected pregnant mice. Widespread evidence of lipid peroxidation was observed and was associated with higher antioxidant gene expression in conceptuses of infected mice. To assess the extent to which this oxidative damage might contribute to poor birth outcomes and be amenable to therapeutic intervention, infected pregnant mice were treated with N-acetylcysteine, a free radical scavenger, or tempol, an intracellular superoxide dismutase mimetic. The results show that mice treated with N-acetylcysteine experienced malaria induced-pregnancy loss at the same rate as control animals and failed to mitigate placental oxidative damage. In contrast, tempol-treated mice exhibited subtle improvement in embryo survival at gestation day 12. Although lipid peroxidation was not consistently reduced in the placentas of these mice, it was inversely related to embryo viability. Moreover, reduced IFN-γ and CCL2 plasma levels in treated mice were associated with midgestational embryo viability. Thus, although oxidative stress is remarkable in placental malaria and its mitigation by antioxidant therapy may improve pregnancy outcomes, the underlying mechanistic basis and potential therapeutic strategies require additional investigation.

Recuperating Lung Decoction Attenuates the Oxidative Stress State of Chronic Obstructive Pulmonary Disease by Inhibiting the MAPK/AP-1 Signal Pathway and Regulating γ-GCS

Purpose/Objective. To evaluate the effects of Recuperating Lung Decoction (RLD) on the indices of oxidative stress in a rat model of COPD and detect the indices of the MAPK/AP-1/γ-GCS signal pathway for a further survey of the possible targeting site of RLD. Methods/Materials. The rats of COPD were treated with RLD. The protein levels of glutathione (GSH), oxidized glutathione (GSSG), 8-hydroxy-2-deoxyguanosine (8-OHdG), and 4-hydroxynonenal (4-HNE) were measured. In addition, the levels of key signaling molecules (extracellular signal-regulated kinases [ERK], the c-jun N-terminal kinase [JNKs signal pathway], and p38 MAP kinase [p38MAPK], AP-1 proteins [C-fos, C-jun], and γ-glutamyl-cysteine synthetase [γ-GCS-h]) of the MAPK/AP-1/γ-GCS-h signal pathway were assessed. Results. After treatment, the protein level of GSH and the ratio of GSH/GSSG were increased and the amounts of 8-OHdG and 4-HNE were decreased significantly in lung tissues when compared with the nontreated COPD group. Further results showed that the RLD could effectively inhibit the MAPK pathway by inactivation of p38MAPK and ERK and could also downregulate the AP-1 and the γ-GCS-h genes expressions in both protein and mRNA levels. Conclusion. RLD might improve the state of oxidative stress by downregulation of the expression of γ-GCS-h gene by inhibition of the MAPK/AP-1 pathway, thereafter enhancing the ability of antioxidation in COPD.

Pharmacological investigation on the anti-oxidant and anti-inflammatory activity of N-acetylcysteine in an ex vivo model of COPD exacerbation

Background

Oxidative stress is recognized to be one of predisposing factor in the pathogenesis of COPD. The oxidant/antioxidant imbalance is significantly pronounced in patients with COPD exacerbation. N-acetylcysteine (NAC) seems to be able to reduce COPD exacerbations by modulating the oxidative stress in addition to its well-known mucolytic activity, but there are discordant findings on the actual anti-oxidant activity of NAC.

Methods

The anti-oxidant effect of NAC and its impact on the inflammatory response have been pharmacologically characterized on a human ex vivo model of COPD exacerbation induced by lipopolysaccharide (LPS).

Results

NAC prevented the desensitization induced by LPS incubation on the contractile tone in linear concentration-response manner. Concentrations of NAC ≥1 μM reduced the pro-oxidant response (peroxidase activity, hydrogen peroxide, malondialdehyde, nitric oxide), and improved the anti-oxidant response (total anti-oxidant capacity, glutathione, superoxide dismutase) induced by LPS. Lower concentrations of NAC (<1 μM) did not modulate the bronchial oxidative imbalance. Concentrations of NAC ≥300 μM inhibited the inflammatory response (release of IL-1β, IL-8, and TNF-α) of human airways induced by the overnight stimulation with LPS, whereas lower concentrations of NAC (≥1 μM) were sufficient to reduce the release of IL-6 elicited by LPS. Both the anti-oxidant effect and the anti-inflammatory effect of NAC were inversely correlated with the release of NKA.

Conclusions

The findings of this study suggest that NAC may have a role in modulating the detrimental effect induced by LPS in course of COPD exacerbation. It may elicit both anti-oxidant and anti-inflammatory effects when administered at high concentrations.

N-Acetylcysteine Combined with Home Based Physical Activity: Effect on Health Related Quality of Life in Stable COPD Patients- A Randomised Controlled Trial

INTRODUCTION

Quality of life is adversely affected in Chronic Obstructive Pulmonary Disease (COPD), due to irreversible, progressive nature of the disease and limitations of current treatment options available. One of the important aim of treatment of COPD is to improve Quality of Life (QoL). Cigarette smoke contains numerous free radicals and other oxidants. Oxidative stress has been implicated in pathogenesis, progression of disease and exacerbation in COPD. Pulmonary tuberculosis, outdoor and indoor air pollution and many others are aetiologies of COPD in non-smokers. N-Acetylcysteine (NAC) is a precursor of endogenous anti-oxidant, Glutathione (GSH) and both agents act as free radical scavengers. Exercise limitation results in poor physical performance and eventually poor QoL in COPD.

AIM

To observe the combined effect of 600mg of NAC once daily and physical activity (home based) in addition to standard treatment for ten weeks, compared with placebo as control group with standard treatment.

MATERIALS AND METHODS

This randomised controlled trial was conducted at a tertiary care centre in Mumbai for two years from December 2011 to December 2013. Hundred patients diagnosed as stable COPD (as per Global Initiative against Obstructive Lung Disease (GOLD) 2010 guidelines) were enrolled in the study. There were 50 patients in study group and control group each. The QoL was assessed using Saint George Respiratory Questionnaire-C (SGRQ-C) initially and at the end of ten weeks. The study group was treated with NAC 600mg once a day combined with daily physical activity in addition to standard treatment. Control group patients were treated with placebo and standard treatment.

RESULTS

At the end of 10 weeks, it was observed that, mean change in SGRQ-C was significant in "study group" as compared to "control group". Mean change in score among study group was 4.72 and the same in control was 1.32, p-value=0.007. There was significant improvement in SGRQ-C score at the end of 10 weeks and QoL in the study group (p-value-0.0001 i.e., <0.05) while improvement in SGRQ-C score and QoL score in control group was not significant (p-value=0.118 i.e., >0.05). Overall, there was statistically significant improvement in SGRQ-C score and QoL (p-value=0.03 i.e., <0.05) in the study group.

CONCLUSION

From the current study, it can be concluded that N-acetylcysteine 600mg once a day and 20 minute daily walk in addition to regular treatment improves QoL in stable COPD patients.

N-acetylcysteine inhibits the up-regulation of mitochondrial biogenesis genes in livers from rats fed ethanol chronically

BACKGROUND

Chronic ethanol (EtOH) administration to experimental animals induces hepatic oxidative stress and up-regulates mitochondrial biogenesis. The mechanisms by which chronic EtOH up-regulates mitochondrial biogenesis have not been fully explored. In this work, we hypothesized that oxidative stress is a factor that triggers mitochondrial biogenesis after chronic EtOH feeding. If our hypothesis is correct, co-administration of antioxidants should prevent up-regulation of mitochondrial biogenesis genes.

METHODS

Rats were fed an EtOH-containing diet intragastrically by total enteral nutrition for 150 days, in the absence or presence of the antioxidant N-acetylcysteine (NAC) at 1.7 g/kg/d; control rats were administered isocaloric diets where carbohydrates substituted for EtOH calories.

RESULTS

EtOH administration significantly increased hepatic oxidative stress, evidenced as decreased liver total glutathione and reduced glutathione/glutathione disulfide ratio. These effects were inhibited by co-administration of EtOH and NAC. Chronic EtOH increased the expression of mitochondrial biogenesis genes including peroxisome proliferator-activated receptor gamma-coactivator-1 alpha and mitochondrial transcription factor A, and mitochondrial DNA; co-administration of EtOH and NAC prevented these effects. Chronic EtOH administration was associated with decreased mitochondrial mass, inactivation and depletion of mitochondrial complex I and complex IV, and increased hepatic mitochondrial oxidative damage, effects that were not prevented by NAC.

CONCLUSIONS

These results suggest that oxidative stress caused by chronic EtOH triggered the up-regulation of mitochondrial biogenesis genes in rat liver, because an antioxidant such as NAC prevented both effects. Because NAC did not prevent liver mitochondrial oxidative damage, extra-mitochondrial effects of reactive oxygen species may regulate mitochondrial biogenesis. In spite of the induction of hepatic mitochondrial biogenesis genes by chronic EtOH, mitochondrial mass and function decreased probably in association with mitochondrial oxidative damage. These results also predict that the effectiveness of NAC as an antioxidant therapy for chronic alcoholism will be limited by its limited antioxidant effects in mitochondria, and its inhibitory effect on mitochondrial biogenesis.

A selective review of glutamate pharmacological therapy in obsessive-compulsive and related disorders

Glutamate, an excitatory central nervous system neurotransmitter, is emerging as a potential alternative pharmacological treatment when compared to gamma-aminobutyric acid (GABA)-, dopamine-, and serotonin-modulating treatments for neuropsychiatric conditions. The pathophysiology, animal models, and clinical trials of glutamate modulation are explored in disorders with underlying inhibitory deficits (cognitive, motor, behavioral) including obsessive–compulsive disorder, attention deficit hyperactivity disorder, Tourette syndrome, trichotillomania, excoriation disorder, and nail biting. Obsessive–compulsive disorder, attention deficit hyperactivity disorder, and grooming disorders (trichotillomania and excoriation disorder) have emerging positive data, although only scarce controlled trials are available. The evidence is less supportive for the use of glutamate modulators in Tourette syndrome. Glutamate-modulating agents show promise in the treatment of disorders of inhibition.

Oxidative stress and respiratory system: pharmacological and clinical reappraisal of N-acetylcysteine

The large surface area for gas exchange makes the respiratory system particularly susceptible to oxidative stress-mediated injury. Both endogenous and exogenous pro-oxidants (e.g. cigarette smoke) trigger activation of leukocytes and host defenses. These mechanisms interact in a "multilevel cycle" responsible for the control of the oxidant/antioxidant homeostasis. Several studies have demonstrated the presence of increased oxidative stress and decreased antioxidants (e.g. reduced glutathione [GSH]) in subjects with chronic obstructive pulmonary disease (COPD), but the contribution of oxidative stress to the pathophysiology of COPD is generally only minimally discussed. The aim of this review was to provide a comprehensive overview of the role of oxidative stress in the pathogenesis of respiratory diseases, particularly COPD, and to examine the available clinical and experimental evidence on the use of the antioxidant N-acetylcysteine (NAC), a precursor of GSH, as an adjunct to standard therapy for the treatment of COPD. The proposed concept of "multilevel cycle" helps understand the relationship between respiratory diseases and oxidative stress, thus clarifying the rationale for using NAC in COPD. Until recently, antioxidant drugs such as NAC have been regarded only as mucolytic agents. Nevertheless, several clinical trials indicate that NAC may reduce the rate of COPD exacerbations and improve small airways function. The most plausible explanation for the beneficial effects observed in patients with COPD treated with NAC lies in the mucolytic and antioxidant effects of this drug. Modulation of bronchial inflammation by NAC may further account for these favorable clinical results.

Antioxidants: The new frontier for translational research in cerebroprotection

It is important for the anesthesiologist to understand the etiology of free radical damage and how free-radical scavengers attenuate this, so that this knowledge can be applied to diverse neuro-pathological conditions. This review will concentrate on the role of reactive species of oxygen in the pathophysiology of organ dysfunction, specifically sub arachnoid hemorrhage (SAH), traumatic brain injury (TBI) as well as global central nervous system (CNS) hypoxic, ischemic and reperfusion states. We enumerate potential therapeutic modalities that are been currently investigated and of interest for future trials. Antioxidants are perhaps the next frontier of translational research, especially in neuro-anesthesiology.

Reactive oxygen species contribute to arsenic-induced EZH2 phosphorylation in human bronchial epithelial cells and lung cancer cells

Our previous studies suggested that arsenic is able to induce serine 21 phosphorylation of the EZH2 protein through activation of JNK, STAT3, and Akt signaling pathways in the bronchial epithelial cell line, BEAS-2B. In the present report, we further demonstrated that reactive oxygen species (ROS) were involved in the arsenic-induced protein kinase activation that leads to EZH2 phosphorylation. Several lines of evidence supported this notion. First, the pretreatment of the cells with N-acetyl-l-cysteine (NAC), a potent antioxidant, abolishes arsenic-induced EZH2 phosphorylation along with the inhibition of JNK, STAT3, and Akt. Second, H2O2, the most important form of ROS in the cells in response to extracellular stress signals, can induce phosphorylation of the EZH2 protein and the activation of JNK, STAT3, and Akt. By ectopic expression of the myc-tagged EZH2, we additionally identified direct interaction and phosphorylation of the EZH2 protein by Akt in response to arsenic and H2O2. Furthermore, both arsenic and H2O2 were able to induce the translocation of ectopically expressed or endogenous EZH2 from nucleus to cytoplasm. In summary, the data presented in this report indicate that oxidative stress due to ROS generation plays an important role in the arsenic-induced EZH2 phosphorylation.

Long-time treatment by low-dose N-acetyl-L-cysteine enhances proinflammatory cytokine expressions in LPS-stimulated macrophages

N-acetyl-L-cysteine is known to act as a reactive oxygen species scavenger and used in clinical applications. Previous reports have shown that high-dose N-acetyl-L-cysteine treatment inhibits the expression of proinflammatory cytokines in activated macrophages. Here, we have found that long-time N-acetyl-L-cysteine treatment at low-concentration increases phosphorylation of extracellular signal-regulated kinase 1/2 and AKT, which are essential for the induction of proinflammatory cytokines including interleukin 1β and interleukin 6 in lipopolysaccharide-stimulated RAW264.7 cells. Furthermore, long-time N-acetyl-L-cysteine treatment decreases expressions of protein phosphatases, catalytic subunit of protein phosphatase-2A and dual specificity phosphatase 1. On the other hand, we have found that short-time N-acetyl-L-cysteine treatment at low dose increases p53 expression, which inhibits expressions of proinflammatory cytokines. These observations suggest that long-time low-dose N-acetyl-L-cysteine treatment increases expressions of proinflammatory cytokines through enhancement of kinase phosphorylation.

Effect of high-dose N-acetylcysteine on airway geometry, inflammation, and oxidative stress in COPD patients

BACKGROUND

Previous studies have demonstrated the potential beneficial effect of N-acetylcysteine (NAC) in chronic obstructive pulmonary disease (COPD). However, the required dose and responder phenotype remain unclear. The current study investigated the effect of high-dose NAC on airway geometry, inflammation, and oxidative stress in COPD patients. Novel functional respiratory imaging methods combining multislice computed tomography images and computer-based flow simulations were used with high sensitivity for detecting changes induced by the therapy.

METHODS

Twelve patients with Global Initiative for Chronic Obstructive Lung Disease stage II COPD were randomized to receive NAC 1800 mg or placebo daily for 3 months and were then crossed over to the alternative treatment for a further 3 months.

RESULTS

Significant correlations were found between image-based resistance values and glutathione levels after treatment with NAC (P = 0.011) and glutathione peroxidase at baseline (P = 0.036). Image-based resistance values appeared to be a good predictor for glutathione peroxidase levels after NAC (P = 0.02), changes in glutathione peroxidase levels (P = 0.035), and reduction in lobar functional residual capacity levels (P = 0.00084). In the limited set of responders to NAC therapy, the changes in airway resistance were in the same order as changes induced by budesonide/formoterol.

CONCLUSION

A combination of glutathione, glutathione peroxidase, and imaging parameters could potentially be used to phenotype COPD patients who would benefit from addition of NAC to their current therapy. The findings of this small pilot study need to be confirmed in a larger pivotal trial.

Emerging treatment options for meibomian gland dysfunction

Meibomian gland dysfunction (MGD) is one of the most common diseases observed in clinics; it influences a great number of people, and is the leading cause of evaporative dry eye. Given the increased recognition of the importance of MGD, a great amount of attention has been paid to therapies targeting this condition. The traditional treatments of MGD consist of warm compresses and lid hygiene for removing an obstructed meibum, as well as antibiotics and anti-inflammatory agents to improve the quality of the meibum. However, each of these treatments has a different shortcoming and the treatment of MGD remains challenging. Despite the numerous possible treatment options for MGD, it is still difficult to obtain complete relief of signs and symptoms. This review focuses on current emerging treatment options for MGD including intraductal meibomian gland probing, emulsion eye drops containing lipids, the LipiFlow® thermal pulsation system, N-acetyl-cysteine, azithromycin, oral supplementation with omega-3 essential fatty acids, and cyclosporine A.

Effects of oral glutathione supplementation on systemic oxidative stress biomarkers in human volunteers

BACKGROUND

The tripeptide glutathione (GSH) is the most abundant free radical scavenger synthesized endogenously in humans. Increasing mechanistic, clinical, and epidemiological evidence demonstrates that GSH status is significant in acute and chronic diseases. Despite ease of delivery, little controlled clinical research data exist evaluating the effects of oral GSH supplementation.

OBJECTIVES

The study objectives were to determine the effect of oral GSH supplementation on biomarkers of systemic oxidative stress in human volunteers.

DESIGN

This was a randomized, double-blind, placebo-controlled clinical trial.

SETTING/LOCATION

The study was conducted at Bastyr University Research Institute, Kenmore, WA and the Bastyr Center for Natural Health, Seattle, WA.

SUBJECTS

Forty (40) adult volunteers without acute or chronic disease participated in this study.

INTERVENTION

Oral GSH supplementation (500 mg twice daily) was given to the volunteers for 4 weeks.

OUTCOME MEASURES

Primary outcome measures included change in creatinine-standardized, urinary F2-isoprostanes (F2-isoP) and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG). Changes in erythrocyte GSH concentrations, including total reduced glutathione (GSH), oxidized glutathione (GSSG), and their ratio (GSH:GSSG) were also measured by tandem liquid chromatography/mass spectrometry. Analysis of variance was used to evaluate differences between groups.

RESULTS

There were no differences in oxidative stress biomarkers between treatment groups at baseline. Thirty-nine (39) participants completed the study per protocol. Changes in creatinine standardized F2-isoP (ng/mg creatinine) (0.0±0.1 versus 0.0±0.1, p=0.38) and 8-OHdG (μg/g creatinine) (-0.2±3.3 versus 1.0±3.2, p=0.27) were nonsignificant between groups at week 4. Total reduced, oxidized, and ratio measures of GSH status were also unchanged.

CONCLUSIONS

No significant changes were observed in biomarkers of oxidative stress, including glutathione status, in this clinical trial of oral glutathione supplementation in healthy adults.

Efficacy of topical N-acetylcysteine in the treatment of meibomian gland dysfunction

PURPOSE

To evaluate the efficacy of topical N-acetyl-cysteine (NAC) therapy in patients with meibomian gland dysfunction (MGD).

METHODS

Twenty patients with MGD were prospectively randomized and assigned into 2 groups. The patients were instructed to use either NAC 5% or preservative-free artificial tear topically 4 times a day for a month. All patients were instructed to apply lid hygiene once daily. Preservative-free artificial tears treated group served as control. Paired sample Student's t-tests were used to detect differences between the baseline and 1 month after treatment initiation in mean ocular symptoms, fluorescein break-up time (FBUT) values, and Schirmer scores in each group. Difference in mean ocular symptoms, Schirmer's test scores, and FBUT values between the baseline and 1 month after treatment initiation were compared between the groups using Mann-Whitney U test.

RESULTS

One month of topical NAC therapy provided statistically significant improvements in FBUT and Schirmer scores as compared with the initial study visit. The average Schirmer increase rate was significantly better in the NAC group than in the control group. Significant improvements for the symptoms of ocular burning, foreign body sensation, and intermittent filmy or blurred vision were noted in both groups; and only NAC-treated group showed improvement for the symptom of itching, at 1 month as compared with 1 day. NAC provided significantly better improvement in itching symptom when compared with controls.

CONCLUSIONS

Topical administration of NAC is thought to be effective and well tolerated in patients with MGD.