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

Endogenous Nitric Oxide Can Enhance Oxidative Stress Caused by Air Pollutants and Explain Higher Susceptibility of Individuals with Inflammatory Disorders

Air pollution causes morbidity and excess mortality. In the epithelial lining fluid of the respiratory tract, air pollutants trigger a chemical reaction sequence that causes the formation of noxious hydroxyl radicals that drive oxidative stress. For hitherto unknown reasons, individuals with pre-existing inflammatory disorders are particularly susceptible to air pollution. Through detailed multiphase chemical kinetic analysis, we show that the commonly elevated concentrations of endogenous nitric oxide in diseased individuals can increase the production of hydroxyl radicals via peroxynitrite formation. Our findings offer a molecular rationale of how adverse health effects and oxidative stress caused by air pollutants may be exacerbated by inflammatory disorders.

Human exposure to diesel exhaust induces CYP1A1 expression and AhR activation without a coordinated antioxidant response

BACKGROUND

Diesel exhaust (DE) induces neutrophilia and lymphocytosis in experimentally exposed humans. These responses occur in parallel to nuclear migration of NF-κB and c-Jun, activation of mitogen activated protein kinases and increased production of inflammatory mediators. There remains uncertainty regarding the impact of DE on endogenous antioxidant and xenobiotic defences, mediated by nuclear factor erythroid 2-related factor 2 (Nrf2) and the aryl hydrocarbon receptor (AhR) respectively, and the extent to which cellular antioxidant adaptations protect against the adverse effects of DE.

METHODS

Using immunohistochemistry we investigated the nuclear localization of Nrf2 and AhR in the epithelium of endobronchial mucosal biopsies from healthy subjects six-hours post exposure to DE (PM10, 300 µg/m3) versus post-filtered air in a randomized double blind study, as a marker of activation. Cytoplasmic expression of cytochrome P450s, family 1, subfamily A, polypeptide 1 (CYP1A1) and subfamily B, Polypeptide 1 (CYP1B1) were examined to confirm AhR activation; with the expression of aldo-keto reductases (AKR1A1, AKR1C1 and AKR1C3), epoxide hydrolase and NAD(P)H dehydrogenase quinone 1 (NQO1) also quantified. Inflammatory and oxidative stress markers were examined to contextualize the responses observed.

RESULTS

DE exposure caused an influx of neutrophils to the bronchial airway surface (p = 0.013), as well as increased bronchial submucosal neutrophil (p < 0.001), lymphocyte (p = 0.007) and mast cell (p = 0.002) numbers. In addition, DE exposure enhanced the nuclear translocation of the AhR and increased the CYP1A1 expression in the bronchial epithelium (p = 0.001 and p = 0.028, respectively). Nuclear translocation of AhR was also increased in the submucosal leukocytes (p < 0.001). Epithelial nuclear AhR expression was negatively associated with bronchial submucosal CD3 numbers post DE (r = -0.706, p = 0.002). In contrast, DE did not increase nuclear translocation of Nrf2 and was associated with decreased NQO1 in bronchial epithelial cells (p = 0.02), without affecting CYP1B1, aldo-keto reductases, or epoxide hydrolase protein expression.

CONCLUSION

These in vivo human data confirm earlier cell and animal-based observations of the induction of the AhR and CYP1A1 by diesel exhaust. The induction of phase I xenobiotic response occurred in the absence of the induction of antioxidant or phase II xenobiotic defences at the investigated time point 6 h post-exposures. This suggests DE-associated compounds, such as polycyclic aromatic hydrocarbons (PAHs), may induce acute inflammation and alter detoxification enzymes without concomitant protective cellular adaptations in human airways.

Withania somnifera (L.) Dunal as Add-On Therapy for COPD Patients: A Randomized, Placebo-Controlled, Double-Blind Study

Background: The current gold-standard therapies for chronic obstructive pulmonary disease (COPD) lack disease-modifying potential and exert adverse side effects. Moreover, COPD patients are at a higher risk of severe outcomes if they get infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, the cause of the current epidemic. This is the first study to document clinical research on an adaptogenic and steroidal activity–containing herb as a complementary medicine for COPD treatment.

Objective: We aimed to evaluate the efficacy of Withania somnifera (L.) Dunal [Solanaceae] (WS) as an add-on therapy for COPD patients.

Methods: A randomized, placebo-controlled, and double-blind clinical study was conducted. A total of 150 patients were randomly assigned to three groups: control, placebo, and WS group. In addition to conventional medicines, WS root capsules or starch capsules were given twice a day to the WS group and the placebo group, respectively. Their lung functioning, quality of life, exercise tolerance, systemic oxidative stress (OS), and systemic inflammation were assessed before and after 12 weeks of intervention. WS root phytochemicals were identified by LC-ESI-MS. The inhibitory activity of these phytochemicals against angiotensin-converting enzyme 2 (ACE-2); the SARS-CoV-2 receptor; myeloperoxidase (MPO); and interleukin-6 (IL-6) was evaluated by in silico docking to investigate the mechanism of action of WS.

Results: The pulmonary functioning, quality of life, and exercise tolerance improved, and inflammation reduced notably the most in the WS group. Systemic oxidative stress subsided significantly only in the WS group. Although a minor placebo effect was observed in the SGRQ test, but it was not present in other tests. Withanolides found in the WS roots demonstrated substantial inhibitory activity against the proteins ACE-2, MPO, and IL-6, compared to that of a standard drug or known inhibitor. Moreover, FEV1% predicted had significant correlation with systemic antioxidative status (positive correlation) and malondialdehyde (MDA, negative correlation), suggesting that the antioxidative potential of WS has significant contribution to improving lung functioning.

Conclusion: Our study clinically demonstrated that WS root when given along with conventional drugs ameliorated COPD significantly more in comparison to the conventional drugs alone, in GOLD 2 and 3 categories of COPD patients. In silico, it has potent inhibitory activity against SARS-CoV-2 receptor, ACE-2, MPO, and IL-6.

The long-term outcomes of tobacco control strategies based on the cognitive intervention for smoking cessation in COPD patients

OBJECTIVE

To evaluate the long-term efficacy of tobacco control strategies based on cognitive intervention for smoking cessation in chronic obstructive pulmonary disease (COPD) patients, and to provide basis for clinical practice.

MATERIALS AND METHODS

102 COPD patients with a long-term history of smoking from the outpatient clinic were recruited in the study. These smokers were randomly divided into intervention group and control group. The intervention group received a cognitive intervention containing individual consultation, telephone follow-ups and self-help materials, etc. The prevalence of quitting smoking, acute exacerbation (AE), lung function and survival were compared in the groups in 10 years.

RESULTS

There were significant differences between the intervention group and the control group in the rate of persistent quitting smoking in half a year (17.6% vs 3.9%) (P < 0.05), the rate of quitting smoking at the 6th month (58.8% vs 33.3%) (P < 0.05). After 3 months (P < 0.01) and 6 months (P < 0.01), the difference in body weight between the intervention group and the control group was statistically significant. Intervention-group patients had fewer AE per year (P < 0.01) and higher FEV1/FVC ratio (P < 0.01) after 5-year and 10-year follow-up. Besides, the FEV1% predicted in the intervention patients was higher than that in control group after 10-year follow-up. The ages of patients in the death group were greater than those in the survival group. Death-group patients had longer smoking times, higher smoking index, and later onset of COPD symptoms. Death-group patients had lower FEV1% predicted (P < 0.05) and FEV1/FVC ratio (P < 0.01). During 10-year follow-up, 30 patient deaths were recorded (the control group: n = 48; 19 deaths, and intervention group: n = 46; 11 deaths), and patients in the control group had lower survival than those in the intervention group. (P < 0.05).

CONCLUSION

The method of quitting smoking based on cognitive intervention is an effective way for COPD patients to quit smoking successfully. Quitting smoking can slower deterioration in lung function and improve the survival of COPD patients.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR2000031239 (Chinese clinical trial registry).

Psychosocial work environment and oxidative stress among nurses'

Background:

Work stress among nurses has increased in recent years due to the demands of clinical nursing.

Objectives:

To investigate psychosocial work stress among nurses using the effort-reward imbalance (ERI) model with assessment malondialdehyde (MDA) as an oxidative stress marker and total antioxidants.

Methods:

The present study was conducted on 204 registered nurses worked at two tertiary hospitals in Menoufia governorate, Egypt through the period from the 1st of February to the end of July 2016. Two questionnaires were applied including general demographic and occupational histories as well as effort-reward questionnaire. Blood analysis was performed to assess MDA and total antioxidant levels.

Results:

ERI was prevalent among the study participants (72.5%). ERI was more prevalent among young married nurses who worked more than 10 years. Nurses that worked at ICUs complained more of ERI (43.2%) while nurses that worked at operation rooms complained more of overcommitment (62.5%). MDA levels were significantly positively correlated with E/R ratios (rho = 0.350, P ≤ 0.001).

Conclusions:

Work stress was prevalent among the studied nurses as revealed by the high ERI and MDA levels. Young married female nurses complained more of work stress. ICUs and operating rooms were the most stressful departments at the studied hospitals. Hence, implementing programs and strategies that eliminate stressful working conditions at hospitals is critical to the reduction and prevention of work stress among nurses.

Smoking cessation affects the natural history of COPD

Background

Cigarette smoking is the most commonly encountered and readily identifiable risk factor for COPD. However, it is not clear which quantitative factors related to smoking influence the prognosis of COPD patients.

Methods

A total of 204 patients with a long-term history of smoking were enrolled into this study and followed up for 5 years. Patients were divided into “death” or “survival” groups based on follow-up results and “quitting-smoking” or “continuing-smoking” groups based on whether they gave up smoking.

Results

Patients in the death group had a longer smoking time, lower prevalence of quitting smoking, later onset of COPD symptoms, older age at quitting smoking, lower forced expiratory volume in one second (FEV₁) % predicted, and lower ratio of FEV₁/forced vital capacity. Age, age at quitting smoking, and FEV₁% predicted were independently associated with mortality from COPD. Compared to the continuing-smoking group, the quitting-smoking group had a lower mortality rate, longer course of COPD, earlier onset of COPD symptoms, and lower residual volume percent predicted. During the 5-year follow-up, 113 deaths were recorded (quitting-smoking group: n=92; 40 deaths; continuing-smoking group: n=112; 73 deaths). The mortality risk remained significantly higher in the continuing-smoking group than the quitting-smoking group (log-rank test, 13.59; P=0.0002).

Conclusion

Smoking time may be related to the mortality rate from COPD. Smoking cessation has the greatest capacity to influence the natural history of COPD.

A prospective randomized controlled study: Theophylline on oxidative stress and steroid sensitivity in chronic obstructive pulmonary disease patients

Objective:

Oxidative stress is involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). Corticosteroid fails to suppress inflammation and oxidative stress due to steroid resistance. Theophylline has an effect on histone deacetylase (HDAC) activity and improves steroid sensitivity in COPD. Given changes in oxidative stress associated with diminished corticosteroid effects, a clinical study in which antioxidants and free radicals are estimated can suggest a correlation between antioxidants, theophylline, and corticosteroid sensitivity.

Materials and Methods:

A randomized controlled study was conducted in 60 participants divided into 4 groups: Group I (controls) - 15 normal healthy volunteers, Group II - COPD patients who received theophylline 300 mg + salbutamol 8 mg, Group III - patients who inhaled budesonide 400 μg + salbutamol 8 mg, and Group IV – theophylline 300 mg + inhaled budesonide 400 μg + salbutamol 8 mg 12 weeks. Blood samples were collected at the time of diagnosis and at 4-week interval for 3 months from all the groups and antioxidant parameters, spirometric % forced expiratory volume in 1 s (FEV₁) were measured.

Results:

The mean difference between groups was analyzed using one-way ANOVA. There was a significant increase in antioxidant enzymes such as catalase, glutathione (GSH) serum transferase, (P < 0.05), reduced GSH, and superoxide dismutase (P < 0.01) and a significant decrease in lipid peroxidation (P < 0.01) at 12 weeks of the study period. Postbronchodilator FEV₁ values have also shown a significant increase at 12 weeks (P < 0.01).

Conclusion:

Theophylline increases the expression and activity of HDAC and improves steroid sensitivity thereby decreases oxidative stress. Hence, novel therapeutic strategy is therefore the reversal of this corticosteroid resistance by increasing the expression and activity of HDAC achieved using corticosteroids along with theophylline.