Changes in blood ROS, e-NO, and some pro-inflammatory mediators in bronchial secretions following erdosteine or placebo: a controlled study in current smokers with mild COPD

[Acute bronchitis - modern possibilities of mucactive therapy]

AIM

Analysis of the clinical effectiveness and safety of erdosteine use in comparison with standard (real practice) mucoactive therapy in patients with acute bronchitis (АВ) in adults.

MATERIALS AND METHODS

The observational program included 100 adult patients with АВ, 50 of them (group 1) received erdosteine, the group 2 also included 50 patients who received acetylcysteine, bromhexine and other mucolytics (real clinical practice). The following were assessed: cough severity, average time for resolution of night and daytime cough, satisfaction with treatment, NO concentration in exhaled air, levels of C-reactive protein (CRP) and interleukin-6 (IL-6).

RESULTS

The average duration of relief of severe daytime cough requiring continued therapy was: in group 1 - 3.7±0.46 days, night cough - 1.14±0.94 days. In the second group, daytime cough was relieved in 3.8±0.4 days, night cough - 1.08±0.7 days. The duration of mucoactive therapy in group 1 was 5.32±0.82 days, in group 2 this figure was 8.5±1.4 days (p<0.05). The number of АВ patients with a significant reduction in the severity of productive cough (1 point on cough severity scale) on the 6th day from the beginning of treatment in group 1 (erdosteine) amounted to 32 (64%), in group 2 - 27 (54%). Satisfaction with the treatment was higher in the group receiving erdosteine: according to the indicators "very satisfied" and "extremely satisfied" the patients of the group 1 - 42 - were the leaders in comparison with the group 2, where these positions were marked by 28 patients. The level of CRP in patients with АВ in group 1 was 24.7±21.24 mg/l, in group 2 - 16.37±16.5 mg/l, which indicates the viral etiology of the process and no need in the prescription of antimicrobial drugs. For the first time in Russian practice, the following were determined: the level of IL-6, which in the group 1 was 10.3±6.7 pc/ml; in the group 2 - 10.03±3.94 pc/ml; the level of exhaled NO in group 1 was 16.5±5.1 ppb, in group 2 - 14.9±4.6 ppb (the norm is up to 25 ppb). These indicators, against the background of mucoactive therapy, decreased to normal values by 6th day.

CONCLUSION

The findings expand our understanding of АВ in adults. New results have been obtained on the role of CRP, IL-6 and NO in exhaled air during АВ. The use of erdosteine was accompanied by a significant mucoactive effect in the form of a pronounced regression of cough in patients with АВ compared to the comparison group in shorter term.

Use of thiols and implications for the use of inhaled corticosteroids in the presence of oxidative stress in COPD

BACKGROUND

Oxidative stress and persistent airway inflammation are thought to be important contributors to the development of chronic obstructive pulmonary disease (COPD). This review summarizes the evidence for targeting oxidative stress and inflammation in patients with COPD with mucolytic/antioxidant thiols and inhaled corticosteroids (ICS), either alone or in combination.

MAIN BODY

Oxidative stress is increased in COPD, particularly during acute exacerbations. It can be triggered by oxidant air pollutants and cigarette smoke and/or by endogenous reactive oxygen species (ROS) released from mitochondria and activated inflammatory, immune and epithelial cells in the airways, together with a reduction in endogenous antioxidants such as glutathione (GSH). Oxidative stress also drives chronic inflammation and disease progression in the airways by activating intracellular signalling pathways and the release of further inflammatory mediators. ICS are anti-inflammatory agents currently recommended for use with long-acting bronchodilators to prevent exacerbations in patients with moderate-to-severe COPD, especially those with eosinophilic airway inflammation. However, corticosteroids can also increase oxidative stress, which may in turn reduce corticosteroid sensitivity in patients by several mechanisms. Thiol-based agents such as erdosteine, N-acetyl L-cysteine (NAC) and S-carboxymethylcysteine (S-CMC) are mucolytic agents that also act as antioxidants. These agents may reduce oxidative stress directly through the free sulfhydryl groups, serving as a source of reducing equivalents and indirectly though intracellular GSH replenishment. Few studies have compared the effects of corticosteroids and thiol agents on oxidative stress, but there is some evidence for greater antioxidant effects when they are administered together. The current Global Initiative for Chronic Obstructive Lung Disease (GOLD) report supports treatment with antioxidants (erdosteine, NAC, S-CMC) in addition to standard-of-care therapy as they have been demonstrated to reduce COPD exacerbations. However, such studies have demonstrated that NAC and S-CMC reduced the exacerbation risk only in patients not treated with ICS, whereas erdosteine reduced COPD exacerbations irrespective of concomitant ICS use suggesting that erdosteine has additional pharmacological actions to ICS.

CONCLUSIONS

Further clinical trials of antioxidant agents with and without ICS are needed to better understand the place of thiol-based drugs in the treatment of patients with COPD.

Disruption of the Molecular Regulation of Mitochondrial Metabolism in Airway and Lung Epithelial Cells by Cigarette Smoke: Are Aldehydes the Culprit?

Chronic obstructive pulmonary disease (COPD) is a devastating lung disease for which cigarette smoking is the main risk factor. Acetaldehyde, acrolein, and formaldehyde are short-chain aldehydes known to be formed during pyrolysis and combustion of tobacco and have been linked to respiratory toxicity. Mitochondrial dysfunction is suggested to be mechanistically and causally involved in the pathogenesis of smoking-associated lung diseases such as COPD. Cigarette smoke (CS) has been shown to impair the molecular regulation of mitochondrial metabolism and content in epithelial cells of the airways and lungs. Although it is unknown which specific chemicals present in CS are responsible for this, it has been suggested that aldehydes may be involved. Therefore, it has been proposed by the World Health Organization to regulate aldehydes in commercially-available cigarettes. In this review, we comprehensively describe and discuss the impact of acetaldehyde, acrolein, and formaldehyde on mitochondrial function and content and the molecular pathways controlling this (biogenesis versus mitophagy) in epithelial cells of the airways and lungs. In addition, potential therapeutic applications targeting (aldehyde-induced) mitochondrial dysfunction, as well as regulatory implications, and the necessary required future studies to provide scientific support for this regulation, have been covered in this review.

Reactive Sulfur Compounds in the Fight against COVID-19

The SARS-CoV-2 coronavirus pandemic outbreak in 2019 resulted in the need to search for an effective and safe strategy for treating infected patients, relieving symptoms, and preventing severe disease. SARS-CoV-2 is an RNA virus that can cause acute respiratory failure and thrombosis, as well as impair circulatory system function. Permanent damage to the heart muscle or other cardiovascular disorders may occur during or after the infection. The severe course of the disease is associated with the release of large amounts of pro-inflammatory cytokines. Due to their documented anti-inflammatory, antioxidant, and antiviral effects, reactive sulfur compounds, including hydrogen sulfide (H₂S), lipoic acid (LA), N-acetylcysteine (NAC), glutathione (GSH), and some other lesser-known sulfur compounds, have attracted the interest of scientists for the treatment and prevention of the adverse effects of diseases caused by SARS-CoV-2. This article reviews current knowledge about various endogenous or exogenous reactive sulfur compounds and discusses the possibility, or in some cases the results, of their use in the treatment or prophylaxis of COVID-19.

Multifaceted Beneficial Effects of Erdosteine: More than a Mucolytic Agent

Erdosteine is a drug approved for the treatment of acute and chronic pulmonary diseases, originally developed as a mucolytic agent. It belongs to the thiol-based family of drugs that are known to also possess potentially important antioxidant and anti-inflammatory properties, and exhibit antibacterial activity against a variety of medically important bacterial species. Erdosteine is a prodrug that is metabolized to the ring-opening compound metabolite M1 (MET 1), which has mucolytic properties. Experimental studies have documented that erdosteine prevents or reduces lung tissue damage induced by oxidative stress and, in particular, that Met 1 also regulates reactive oxygen species production. The RESTORE study, which has been the only trial that investigated the effects of a thiol-based drug in chronic obstructive pulmonary disease (COPD) frequent exacerbators, documented that erdosteine significantly reduces the risk of acute exacerbations of COPD (AECOPDs), shortens their course, and also decreases the risk of hospitalization from COPD. The preventive action of erdosteine on AECOPDs was not affected by the presence or absence of inhaled corticosteroids (ICSs) or blood eosinophil count. These findings clearly contrast with the Global Initiative for Chronic Obstructive Lung Disease strategy’s approach to use erdosteine only in those COPD patients not treated simultaneously with an ICS. Furthermore, they support the possibility of using erdosteine in a step-down approach that in COPD is characterized by the withdrawal of the ICS.

Cough Remedies for Children and Adolescents: Current and Future Perspectives

Cough is a widespread symptom in children and adolescents. Despite advances in scientific knowledge about the neurophysiological mechanisms underlying the cough reflex, the best therapeutic approaches for children and adolescents who cough remain unclear, and many needs are still unmet. Many remedies for cough are self-prescribed, reflecting strong demand, but significant evidence of their efficacy and safety is missing in pediatric populations. Moreover, as most coughs are part of self-limited illnesses, treatment could be considered unnecessary in some patients. Drug therapy to relieve cough and other symptoms is an essential part of treating a child with cough. However, unfortunately, the number of studies in each category of cough medications is minimal, and dosing and treatment duration varies significantly among studies. Some treatments have been shown to be no more effective than placebo. Lack of clear indications for dosing and treatment duration, the number of available drugs, the numerous active ingredients in products, and multiple caregivers administering medication to children have been considered contributors to an increased risk of inappropriate prescribing, accidental overdosing, and adverse events. This review presents the most recent evidence on the safety and efficacy of available cough remedies, focusing on the pediatric age group, and includes H₁ receptor antagonists, mucolytics and expectorants, drugs acting peripherally on the cough reflex, drugs acting centrally on the cough reflex, drugs acting both peripherally and centrally on the cough reflex, and other compounds, including menthol, glycerol, honey, and medical devices composed of complex natural substances. Future perspectives on new therapeutic targets are also discussed.

The effect of erdosteine on airway defence mechanisms and inflammatory cytokines in the settings of allergic inflammation

INTRODUCTION

Mucoactive agent, erdosteine, besides mucolytic activity, is characterized by many other pharmacodynamic properties which could be beneficial in the management of inflammatory conditions.

BACKGROUND

Using guinea pig experimental model of allergic inflammation, we evaluated the ability of erdosteine to modulate airway defence mechanisms and inflammation after 10 days (10 mg/kg/day) administration.

METHODS

In vivo changes in specific airway resistance and amplitude of tracheal contraction were estimated to evaluate the bronchodilatory effect. The sensitivity of chemically induced cough reflex was estimated via in vivo method. The ciliary beat frequency assessed on brushed tracheal cells was used as an indicator of the mucociliary clearance rate. The concentrations of the inflammatory cytokines IL-4, IL-5, IL-13 and IL-10 were measured in BALF using multiplex detecting method.

RESULTS

Our data show that 10 days erdosteine administration resulted in bronchodilation and stimulation of ciliary beat frequency. Erdosteine did not affect the parameters of chemically induced cough reflex. Erdosteine demonstrated the modest decline in inflammatory cytokines IL-5, IL-13 and an increase in the concentration of IL-10, which is a potent regulator of inflammatory responses and plays a critical role in controlling allergic airway inflammation.

CONCLUSION

In summary, we can state, that erdosteine is multi-action drug and it seems to have many beneficial and complementary effect in the management of chronic inflammatory airway diseases complicated by viscous mucus.

Erdosteine: Drug exhibiting polypharmacy for the treatment of respiratory diseases

Mucoactive drugs are commonly used in the treatment of acute respiratory tract diseases, such as lower and acute respiratory infection and chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD) in which an increased mucus secretion is one of main clinical features. Indeed these drugs are designed to promote secretion clearance and to specifically alter the viscoelastic properties of mucus, restoring an effective mucociliary clearance and reducing broncho-obstructive symptoms. In association with mucolytics, these patients frequently also receive antibiotics to reduce the bacterial load, thus decreasing the release of infectious and pro-inflammatory products. Erdosteine is one of the most used mucoactive agents for the treatment of several respiratory diseases where the overlap of bacterial infection is frequent. Although the effectiveness in the reducing mucus in acute and chronic respiratory disease has been demonstrated for others mucolytic, some of them when given in combination with an antibiotic therapy, could reduce the antibiotic efficacy in some situation. Differently, erdosteine potentiates the antibiotic effect when given in combination with antibiotics. We have reviewed the literature available on both clinical and in vitro studies that have investigated this effect of erdosteine on the effect of antibiotics when used as combined therapy.

Effect of erdosteine on the rate and duration of COPD exacerbations: the RESTORE study

Oxidative stress contributes to chronic obstructive pulmonary disease (COPD) exacerbations and antioxidants can decrease exacerbation rates, although we lack data about the effect of such drugs on exacerbation duration.

The RESTORE (Reducing Exacerbations and Symptoms by Treatment with ORal Erdosteine in COPD) study was a prospective randomised, double-blind, placebo-controlled study, enrolling patients aged 40–80 years with Global Initiative for Chronic Obstructive Lung Disease stage II/III. Patients received erdosteine 300 mg twice daily or placebo added to usual COPD therapy for 12 months. The primary outcome was the number of acute exacerbations during the study.

In the pre-specified intention-to-treat population of 445 patients (74% male; mean age 64.8 years, forced expiratory volume in 1 s 51.8% predicted) erdosteine reduced the exacerbation rate by 19.4% (0.91 versus. 1.13 exacerbations·patient⁻¹·year⁻¹ for erdosteine and placebo, respectively; p=0.01), due to an effect on mild events; the reduction in the rate of mild exacerbations was 57.1% (0.23 versus 0.54 exacerbations·patient⁻¹·year⁻¹ for erdosteine and placebo, respectively; p=0.002). No significant difference was observed in the rate of moderate and severe exacerbations (0.68 versus 0.59 exacerbations·patient⁻¹·year⁻¹ for erdosteine and placebo, respectively; p=0.054) despite a trend in favour of the comparison group. Erdosteine decreased the exacerbation duration irrespective of event severity by 24.6% (9.55 versus 12.63 days for erdosteine and placebo, respectively; p=0.023). Erdosteine significantly improved subject and physician subjective severity scores (p=0.022 and p=0.048, respectively), and reduced the use of reliever medication (p<0.001), but did not affect the St George's Respiratory Questionnaire score or the time to first exacerbation.

In patients with COPD, erdosteine can reduce both the rate and duration of exacerbations. The percentage of patients with adverse events was similar in both the placebo and erdosteine treatment groups.

RESTORE study: erdosteine reduces both rate and duration of COPD exacerbations with a placebo-like safety profilehttp://ow.ly/BbGI30dRdEt

Erdosteine reduces the exercise-induced oxidative stress in patients with severe COPD: Results of a placebo-controlled trial

BACKGROUND

Erdosteine (ER), a multimechanism, mucoactive agent with anti-oxidant and anti-inflammatory properties, has been shown to improve lung function, decrease plasma reactive oxygen species (ROS), and 8-isoprostane levels in patients with chronic obstructive pulmonary disease (COPD).

AIM

To assess vs. placebo the effect of ER on the exercise-induced oxidative stress by measuring and comparing the release of pro-inflammatory mediators in severe COPD patients.

METHODS

The double blind, placebo controlled study was carried out in 24 severe (GOLD Class III) COPD patients, aged >40 yr, randomized to receive either oral ER (600 mg/day, 8 males, mean age 70.5 yr) or placebo (9 males, mean age 70.8 yr) for 10 days. All patients performed a 6-min walking test (6MWT) before and after both treatments.

RESULTS

Mean ROS plasma levels increased significantly, but equally, in each group following the baseline 6MWT (p = ns). At the end of both treatments, a significant difference in mean plasma ROS increase from baseline became clear between the ER (+14.6% ± 2.7) and the placebo group (+24.4% ± 3.8) after the second 6MWT (p < 0.025). A similar significant trend was proved for the mean 8-isoprostane increase, which changed from baseline by +14.1% ± 2.6 in the ER, and by +26.3 ± 2.9 in the placebo group, respectively, after the second 6MWT (p < 0.006).

CONCLUSIONS

Data from the present study are suggesting that ER is effective in reducing the release of inflammatory mediators due to the exercise-induced oxidative stress in severe COPD patients.

Erdosteine reduces inflammation and time to first exacerbation postdischarge in hospitalized patients with AECOPD

Purpose

Mucolytics can improve disease outcome in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The objectives of this study were to investigate the effects of erdosteine (ER), a mucolytic agent with antioxidant activity, on systemic inflammation, symptoms, recurrence of exacerbation, and time to first exacerbation postdischarge in hospitalized patients with AECOPD.

Patients and methods

Patients admitted to hospital with AECOPD were randomized to receive either ER 900 mg daily (n=20) or a matching control (n=20). Treatment was continued for 10 days until discharge. Patients also received standard treatment with steroids, nebulized bronchodilators, and antibiotics as appropriate. Serum C-reactive protein levels, lung function, and breathlessness–cough–sputum scale were measured on hospital admission and thereafter at days 10 and 30 posttreatment. Recurrence of AECOPD-requiring antibiotics and/or oral steroids and time to first exacerbation in the 2 months (days 30 and 60) postdischarge were also assessed.

Results

Mean serum C-reactive protein levels were lower in both groups at days 10 and 30, compared with those on admission, with significantly lower levels in the ER group at day 10. Improvements in symptom score and forced expiratory volume in 1 second were greater in the ER than the control group, which reached statistical significance on day 10. ER was associated with a 39% lower risk of exacerbations and a significant delay in time to first exacerbation (log-rank test P=0.009 and 0.075 at days 30 and 60, respectively) compared with controls.

Conclusion

Results confirm that the addition of ER (900 mg/d) to standard treatment improves outcomes in patients with AECOPD. ER significantly reduced airway inflammation, improved the symptoms of AECOPD, and prolonged time to first exacerbation. The authors suggest ER could be most beneficial in patients with recurring, prolonged, and/or severe exacerbations of COPD.

Adipokine CTRP-5 as a Potential Novel Inflammatory Biomarker in Chronic Obstructive Pulmonary Disease

Local and systemic inflammation often present in chronic obstructive pulmonary disease (COPD). Adipokines are secretory protein mediators by adipose tissue, which have been found to involve in inflammatory responses in many chronic inflammatory diseases. Therefore, we performed this preliminary clinical study to investigate the possible association between 2 adipokines, C1q/tumor necrosis factor-related protein-3 and -5 (CTRP-3 and CTRP-5), with lung function and other markers of inflammation in COPD. Serum CTRP-3 and CTRP-5 levels were measured in 73 COPD patients and 54 health controls, together with lung function and levels of adiponectin, CRP, TNF-α, and MPO in both groups. Pearson's partial correlation was used to analyze the correlations between CTRPs and other serum markers or lung function. Serum CTRP-5 was significantly elevated in COPD patients (0.41 ± 0.35 versus 0.29 ± 0.28 μg/ml, P = 0.01) and correlated inversely with FEV1/FVC ratio in all patients (r = -0.31, P = 0.001). In COPD patients, CTRP-5 was also correlated negatively with FEV1% predicted (r = -0.464, P < 0.001) and had a positive association with CRP levels (r = 0.262, P = 0.04). However, serum CTRP-3 levels were not correlated with measures of lung function or systemic inflammation. In conclusion, circulating CTRP-5 was associated with the severity of airflow obstruction and systemic inflammation in patients with COPD, which suggests that it may be used as a potential novel inflammatory biomarker in COPD. Further studies should be performed to clarify the exact role of CTRP-5 on the pathogenesis and outcomes of COPD.

Protective effects of erdosteine against nephrotoxicity caused by gamma radiation in male albino rats

The aim of this study was focused on investigating the possible protective effect of erdosteine against gamma radiation-induced renal lesions in male albino rats. Twenty-eight albino rats were divided into four equal groups as follows: control group, irradiated group (animals subjected to whole-body gamma irradiation at a dose of 5 Gy), treated group (each rat received 100 mg/kg body weight once daily, orally by gastric tube, erdosteine for 1 week), and treated irradiated group (each rat received 100 mg/kg body weight once daily, orally by gastric tube, erdosteine for 1 week, then exposed to whole-body gamma irradiation at a dose of 5 Gy). The results revealed that the administration of erdosteine to rats before irradiation significantly ameliorated the changes occurred in kidney function (creatinine and urea) compared with irradiated group. Also the changes in serum tumor necrosis factor α, interleukin 1β, and interleukin 6 activities were markedly improved compared with the corresponding values of irradiated group. Kidney catalase and glutathione peroxidase (GPx) activities and reduced glutathione concentration showed approximately normal level when compared with the irradiated group. The histopathological results showed distinctive pattern of renal lesions in irradiated group, while in treated irradiated group the renal tissues showed relatively well-preserved architecture. Erdosteine acts in the kidney as a potent scavenger of free radicals to prevent or ameliorate the toxic effects of gamma irradiation as shown in the biochemical and histopathological changes and might provide substantial protection against radiation-induced inflammatory damage.

Update on the pathological processes, molecular biology, and clinical utility of N-acetylcysteine in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common and morbid disease characterized by high oxidative stress. Its pathogenesis is complex, and involves excessive oxidative stress (redox imbalance), protease/antiprotease imbalance, inflammation, apoptosis, and autoimmunity. Among these, oxidative stress has a pivotal role in the pathogenesis of COPD by initiating and mediating various redox-sensitive signal transduction pathways and gene expression. The protective physiological mechanisms of the redox balance in the human body, their role in the pathogenesis of COPD, and the clinical correlation between oxidative stress and COPD are reviewed in this paper. N-acetylcysteine (NAC) is a mucolytic agent with both antioxidant and anti-inflammatory properties. This paper also reviews the use of NAC in patients with COPD, especially the dose-dependent properties of NAC, eg, its effects on lung function and the exacerbation rate in patients with the disease. Earlier data from BRONCUS (the Bronchitis Randomized on NAC Cost-Utility Study) did not suggest that NAC was beneficial in patients with COPD, only indicating that it reduced exacerbation in an “inhaled steroid-naïve” subgroup. With regard to the dose-dependent properties of NAC, two recent randomized controlled Chinese trials suggested that high-dose NAC (1,200 mg daily) can reduce exacerbations in patients with COPD, especially in those with an earlier (moderately severe) stage of disease, and also in those who are at high risk of exacerbations. However, there was no significant effect on symptoms or quality of life in patients receiving NAC. Further studies are warranted to investigate the effect of NAC at higher doses in non-Chinese patients with COPD.

Increased serum ox-LDL levels correlated with lung function, inflammation, and oxidative stress in COPD

Chronic obstructive pulmonary disease (COPD) is associated with abnormal inflammation and high oxidative stress. Studies suggest that oxidized low density lipoprotein (ox-LDL) is involved in diseases associated with oxidative stress and inflammation. However, no data on the possible relationship between COPD and ox-LDL are available. This study compared serum levels of ox-LDL in 48 COPD patients and 32 health controls and correlated them with lung function, systematic inflammation, and oxidative stress. Serum levels of ox-LDL, C-reactive protein (CRP), and oxidative stress (measured by reactive oxygen species, ROS) were analyzed using commercial kits. Mean levels of serum ox-LDL were significantly higher in COPD patients than in controls (18.62 ± 7.56 versus 12.57 ± 5.90 mU/L, P < 0.05). Serum levels of CRP and ROS were also significantly higher in COPD patients. Serum levels of ox-LDL in COPD patients correlated inversely with FEV₁% predicted, an index of lung function (r = −0.347, P = 0.016), while they correlated positively with CRP and ROS levels. These results suggest that serum levels of ox-LDL are increased in COPD patients and that these levels are associated with lung function, inflammation, and oxidative stress in COPD. Future studies are needed to determine whether and how ox-LDL plays a role in COPD.

Prevention of pulmonary complications of pneumoperitoneum in rats

Background

Carbon dioxide (CO₂) pneumoperitoneum facilitates the visualization of abdominal organs during laparoscopic surgery. However, the associated increase in intra-abdominal pressure causes oxidative stress, which contributes to tissue injury.

Objective

We investigated the ability of the antioxidant and anti-inflammatory drug Erdosteine to prevent CO₂ pneumoperitoneum-induced oxidative stress and inflammatory reactions in a rat model.

Methods

Fourteen female adult Wistar albino rats were divided into a control group (Group A, n = 7) and an Erdosteine group (Group B, n = 7). Group A received 0.5 cc/day 0.9% NaCl, and Group B received 10 mg/kg/day Erdosteine was administered by gavage, and maintained for 7 days prior to the operation. During the surgical procedure, the rats were exposed to CO₂ pneumoperitoneum with an intra-abdominal pressure of 15 mmHg for 30 min. The peritoneal gas was then desufflated. The rats were sacrificed following 3 h of insufflation. Their lungs were removed, histologically evaluated, and scored for intra-alveolar hemorrhage, alveolar edema, congestion, and leukocyte infiltration. The results were statistically analyzed. A value of P < 0.05 was considered statistically significant.

Results

Significant differences were detected in intra-alveolar hemorrhage (P < 0.05), congestion (P < 0.001), and leukocyte infiltration (P < 0.001) in Group A compared with Group B. However, the differences in alveolar edema were not statistically significant (P = 0.698).

Conclusions

CO₂ pneumoperitoneum results in oxidative injury to lung tissue, and administration of Erdosteine reduces the severity of pathological changes. Therefore, Erdosteine may be a useful preventive and therapeutic agent for CO₂ pneumoperitoneum-induced oxidative stress in laparoscopic surgery.

Beneficial effect of erdosteine on methotrexate-induced testicular toxicity in mice

Methotrexate is used to treat certain types of cancer of the breast, skin, head and neck, or lung. Methotrexate can cause serious or life-threatening side effects on liver, lungs, kidneys, and immune system. Methotrexate chemotherapy causes testicular damage in humans. The aim of this study was to investigate the possible protective role of erdosteine on testicular toxicity of methotrexate in mice. Twenty-six male mice were divided into four groups as follows: group 1, control; group 2, erdosteine-treated; group 3, methotrexate-treated; and group 4, methotrexate + erdosteine treated. On the first day of experiment, a single dose of methotrexate was intraperitoneally administered to groups 3 and 4, although a daily single dose of erdosteine was orally administered to group 2 and 4 for 7 days. At the end of the experiment, the testes of the animals were removed and weighed. The levels of total antioxidant capacity and total oxidative stress, and myeloperoxidase activity in the methotrexate group were higher than the control group (p<0.05). Lipid peroxidation levels were not changed in methotrexate group compared with control group. In conclusion, erdosteine could effectively protect the testes in methotrexate-induced toxicity.

Pharmacologic management of cough

This review is an update of recent advances in our understanding of cough suppressants and impairment of cough. Low-dose oral morphine has recently been shown to significantly suppress chronic cough, but the side effect profile of this opioid may limit its widespread utility. Several studies have demonstrated a dissociation between the efficacy of antitussives in some metrics of pathologic cough and their effects on cough sensitivity to inhaled irritants. The relevance of widely used inhaled irritants in understanding pathologic cough and its response to antitussives is questionable. A recent advance in the field is the identification and measurement of an index of sensation related to cough: the urge to cough. This measure highlights the potential involvement of suprapontine regions of the brain in the genesis and potential suppression of cough in the awake human. There are no new studies showing that mucolytic agents are of value as monotherapies for chronic cough. However, some of these drugs, presumably because of their antioxidant activity, may be of use as adjunct therapies or in selected patient populations. The term dystussia (impairment of cough) has been coined recently and represents a common and life-threatening problem in patients with neurologic disease. Dystussia is strongly associated with severe dysphagia and the occurrence of both indicates that the patient has a high risk for aspiration. No pharmacologic treatments ae available for dystussia, but scientists and clinicians with experience in studying chronic cough are well qualified to develop methodologies to address the problem of impaired cough.

Erdosteine: its relevance in COPD treatment

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a progressive condition characterized by airflow limitation, which is largely irreversible; the oxidant/antioxidant imbalance is important in the pathogenesis of this condition.

OBJECTIVE

To show that administration of erdosteine, a mucolytic agent with a prevalent antioxidant activity, could play a beneficial role in COPD.

METHODS

To review the experimental and clinical trials on erdosteine in COPD and chronic bronchitis.

RESULTS

Erdosteine is a thiol agent with a multifactorial mechanism of action, namely: mucolytic, antibacterial, antioxidant and anti-inflammatory activity. In the acute exacerbation of chronic bronchitis/COPD, addition of erdosteine 300 mg twice a day for 7 - 10 days to standard treatment improves the symptoms and reduces the time of disease. In clinically stable COPD, long-term treatment is associated with a reduction in acute exacerbation and hospitalization rate and a significant improvement of quality of life. Erdosteine could be most beneficial in patients who have repeated, prolonged or severe exacerbations of COPD.

Antioxidant therapeutic advances in COPD

Chronic obstructive pulmonary disease (COPD) is associated with a high incidence of morbidity and mortality. Cigarette smoke-induced oxidative stress is intimately associated with the progression and exacerbation of COPD and therefore targeting oxidative stress with antioxidants or boosting the endogenous levels of antioxidants is likely to have beneficial outcome in the treatment of COPD. Among the various antioxidants tried so far, thiol antioxidants and mucolytic agents, such as glutathione, N-acetyl-L-cysteine, N-acystelyn, erdosteine, fudosteine and carbocysteine; Nrf2 activators; and dietary polyphenols (curcumin, resveratrol, and green tea catechins/quercetin) have been reported to increase intracellular thiol status along with induction of GSH biosynthesis. Such an elevation in the thiol status in turn leads to detoxification of free radicals and oxidants as well as inhibition of ongoing inflammatory responses. In addition, specific spin traps, such as alpha-phenyl-N-tert-butyl nitrone, a catalytic antioxidant (ECSOD mimetic), porphyrins (AEOL 10150 and AEOL 10113), and a SOD mimetic M40419 have also been reported to inhibit cigarette smoke-induced inflammatory responses in vivo in the lung. Since a variety of oxidants, free radicals and aldehydes are implicated in the pathogenesis of COPD, it is possible that therapeutic administration of multiple antioxidants and mucolytics will be effective in management of COPD. However, a successful outcome will critically depend upon the choice of antioxidant therapy for a particular clinical phenotype of COPD, whose pathophysiology should be first properly understood. This article will review the various approaches adopted to enhance lung antioxidant levels, antioxidant therapeutic advances and recent past clinical trials of antioxidant compounds in COPD.

Erdosteine enhances airway response to salbutamol in patients with mild-to-moderate COPD

Background: Oxidative stress is presumed to impair β-adenoceptor function and airway patency. Erdosteine (E), a mucomodulatory compound, has shown important antioxidant properties.

Methods: The objective was to assess the effect of antioxidant interventions on short-term airway response to salbutamol in non-reversible mild-to-moderate COPD patients. Thirty COPD patients (GOLD class 1—2), current smoker (≥10 pack/year), randomly received E 300 mg, N-acetylcysteine (NAC) 600 mg, or placebo, twice daily for ten days. Reversibility to salbutamol 200 μg was tested in baseline, after four and ten days of each treatment. ROS and 8-isoprostane blood levels were measured on the same days. Between-treatment comparison was performed by ANOVA and t-test or Wilcoxon test, and p<0.05 assumed. E enhanced FEV1 reversibility after four and ten days significantly (+5.1% and +5.0%; both p<0.01 vs. placebo), while NAC only showed a transient effect at day 4 (+3.0%, p<0.05), but not at day 10 (+1.3%, p = ns).

Results: E and NAC caused significant drops in ROS blood levels after four and ten days (p<0.001 and p<0.0001 vs. placebo). In contrast to NAC, E lowered 8-isoprostane levels substantially for ten days (p = 0.017 and p = 0.0004 vs. placebo, respectively). Only E restored significantly short-term reversibility in COPD patients previously unresponsive to β2-adrenergics.

Conclusions: This effect seems more related to the peculiar protection against lipid peroxidation rather than to the scavenging activity, which proves equal to that of NAC. E provides a sort of indirect bronchodilation through 're-sensitisation' of β 2-adrenoceptors. Once confirmed in further controlled studies, it may be useful in long-term treatment of COPD.

Erdosteine: antitussive and anti-inflammatory effects

Erdosteine is a multifactorial drug currently used in COPD for its rheologic activity on bronchial secretions and its positive effects on bacterial adhesiveness. Erdosteine produces an active metabolite (Met 1) which was shown to produce antioxidant effects during the respiratory burst of human PMNs, due to the presence of an SH group. The substantial antitussive effects of erdosteine were first documented in clinical trials even though mucolytic agents are regarded as not consistently effective in ameliorating cough in patients with bronchitis, although they may be of benefit to this population in other ways. Actually, a mucolytic drug could exert antitussive effects if it also affects mucus consistency and enhances ciliary function. In the last decade, data from several studies on animal models pointed to the possible antitussive and anti-inflammatory properties of erdosteine and an indirect anti-inflammatory mechanism of action was suggested. Recently, data from some controlled versus placebo studies documented the antioxidant properties of erdosteine in humans and in current smokers with COPD. The mechanism of action was described as related to erdosteine's ability to inhibit some inflammatory mediators and some pro-inflammatory cytokines that are specifically involved in oxidative stress. As oxidative stress is also presumed to impair beta-adrenoceptor function and contribute to airway obstruction, specific controlled studies recently investigated the effect of antioxidant intervention on short-term airway response to salbutamol in nonreversible COPD, according to a double-blind design versus placebo and NAC. Only erdosteine consistently restored a significant short-term reversibility in COPD subjects, previously unresponsive to beta(2) adrenergics. This peculiar activity of erdosteine (to our knowledge never previously assessed) proved related to the ROS scavenging activity (which actually proved equal to that of N), and its significant inhibiting effect on lipoperoxidation (8-isoprostane) proved discriminant between treatments, with antioxidant and anti-inflammatory effects the main determinants of the erdosteine multifactorial properties. In addition, antitussive effects may be regarded as related to its anti-inflammatory properties via the improvement of mucociliary clearance and the reduction of chemokines from epithelial cells. Finally, a sort of "sensitization" of 2-adrenoceptors can also be speculated due to the same mechanisms of action; if confirmed by further controlled studies, this particular property would suggest a novel therapeutic role of erdosteine in COPD.