Vitamin C prevents cigarette smoke-induced pulmonary emphysema in mice and provides pulmonary restoration

Chronic Obstructive Pulmonary Disease: The Role of Healthy and Unhealthy Dietary Patterns-A Comprehensive Review

Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible disease affecting many people worldwide. Recent evidence suggests that diet and lifestyle play a vital role in COPD progression. We aimed to provide a comprehensive review of the effect of healthy and unhealthy dietary patterns on preventing and treating COPD. For this reason, Scopus, EMBASE, Web of Science, and PubMed were searched. Based on our findings, it appears that adhering to a healthy dietary pattern rich in vegetables, legumes, fruit, nuts, and whole grains may have advantageous impacts on preventing and treating COPD while following an unhealthy dietary pattern rich in red and processed meat, saturated fats, sweets, and sugary drinks affect COPD negatively. Adhering to Mediterranean, dietary approaches to stop hypertension (DASH), Prudent, Ketogenic, and High-protein diet may be related to a lower risk of COPD and improved pulmonary function. Conversely, Western and Ramadan Intermittent Fasting diets may elevate the prevalence of COPD. Proposing a nutritious diet that enhances pulmonary function could potentially be an effective approach to preventing and managing COPD. A comprehensive knowledge of the relationship between dietary factors and COPD can provide healthcare professionals with properly supported approaches to advise patients and empower individuals to make informed lifestyle decisions that are beneficial to improve their pulmonary health.

The Associations Between Serum Vitamins and Carotenoids with Chronic Obstructive Pulmonary Disease: Results from the NHANES

Purpose

Vitamins and carotenoids are essential in preventing and treating chronic obstructive pulmonary disease (COPD). This study investigated the associations between serum vitamins, carotenoids, and COPD in adults aged ≥ 40 years in the United States.

Methods

We selected 3487 participants aged ≥40 from the NHANES (2017-2018) and used demographic analysis, sensitivity tests, and different weighted multivariate regression models to investigate the relationship between serum vitamins, carotenoids, and COPD.

Results

Subjects in the highest tertile of serum vitamin C, vitamin E (α-tocopherol), α-carotene, trans-β-carotene, and cis-β-carotene had a 50%, 35%, 51%, 54%, and 51% lower risk of COPD than those in the lowest tertile (P for trend: P=0.0005, <0.0001, 0.0054, 0.0066, and 0.0049). Unfortunately, no significant correlation was found for serum vitamin D levels.

Conclusion

Our analysis of nationally representative data from 3487 participants showed that serum levels of vitamin C, vitamin E (α-tocopherol), α-carotene, and β-carotene were negatively associated with the incidence of COPD in adults over 40 years of age in the US The findings highlighted the importance of antioxidant vitamins and carotenoids in respiratory health, while the data showed no significant correlation between vitamin D (25-OHD) and the incidence of COPD.

Maternal consumption of l-malic acid enriched diets improves antioxidant capacity and glucose metabolism in offspring by regulating the gut microbiota

Maternal diets during pregnancy and lactation are key determinants that regulate the development of metabolic syndrome (MetS) in offspring. l-malic acid (MA) was previously reported to improve antioxidant capacity and aerobic metabolism. However, the effects of maternal MA consumption on the metabolic features of offspring remain largely unexplored. Herein, through pig models consuming MA-enriched diets during late pregnancy and lactation, we found that maternal MA consumption potentiated the anti-inflammatory and antioxidant capacity of sows, thereby improving their reproductive performance and the growth performance of piglets. Maternal MA consumption also induced a transition of slow-twitch to fast-twitch fibers in the early life of offspring. Along with muscle growth and fiber-type transition, insulin sensitivity and glucose metabolism, including aerobic metabolism and glycolysis, were improved in the skeletal muscle of offspring. An untargeted metabolomic analysis further revealed the contribution of modified amino acid metabolism to the improved aerobic metabolism. Mechanistically, maternal MA consumption remodeled colonic microbiota of their offspring. Briefly, the abundance of Colidextribacter, Romboutsia, and Family_XIII_AD3011_group increased, which were positively associated with the antioxidant capacity and glucose metabolism of skeletal muscles. A decreased abundance of Prevotella, Blautia, Prevotellaceae_NK3B31_group, and Collinsella was also detected, which were involved in less insulin sensitivity. Notably, milk metabolites, such as ascorbic acid (AA) and granisetron (GS), were found as key effectors regulating the gut microbiota composition of piglets. The properties of AA and GS in alleviating insulin resistance, inflammation, and oxidative stress were further verified through mice treated with high-fat diets. Overall, this study revealed that maternal MA consumption could modulate the inflammatory response, antioxidant capacity, and glucose metabolism by regulating the gut microbiota of offspring through the vertical transmission of milk metabolites. These findings suggest the potential of MA in the prevention and treatment of MetS in early life.

The effects of vitamin C on respiratory, allergic and immunological diseases: an experimental and clinical-based review

Vitamin C is used in modern medicine supplements for treatment of various disorders associated with oxidative stress, inflammation and immune dysregulation. In this review article, experimental and clinical results regarding the effects of vitamin C on respiratory immunologic, and allergic diseases are reviewed. Various databases and appropriate keywords are used to search the effect of vitamin C on respiratory diseases until the end of May 2022. Books, theses and articles were included. These studies assessed the effects of vitamin C on respiratory disorders including asthma, chronic obstructive pulmonary disease (COPD), lung infection and lung cancer. Vitamin C showed relaxant effect on tracheal smooth muscle via various mechanisms. The preventive effects of vitamin C were mediated by antioxidant, immunomodulatory and anti-inflammatory mechanisms in the experimental animal models of different respiratory diseases. Some clinical studies also indicated the effect of vitamin C on lung cancer and lung infections. Therefore, vitamin C could be used a preventive and/or relieving therapy in respiratory diseases.

Association of oxidative balance score and lung health from the National Health and Nutrition Examination Survey 2007-2012

Background

Oxidative stress is associated with outcomes of chronic lung disease. The oxidative stress-related exposures of diet and lifestyle can be evaluated by the oxidative balance score (OBS), and higher OBS scores indicate more significant antioxidant exposures. But the relationship between OBS and lung health is unknown.

Purpose

The aim of this study was to explore the association between OBS and lung health (respiratory symptoms, chronic lung disease, and lung function).

Methods

A series of models, including weighted linear models, weighted logistic regression, and weighted multinomial logistic regression, were performed to assess the associations of OBS with respiratory symptoms, chronic lung disease, and lung function. The models adjusted by age, race/ethnicity, gender, educational background, poverty-to-income ratio, and dietary energy were also performed.

Results

Cross-sectional data of 5,214 participants from the National Health and Nutrition Examination Survey for the years 2007-2012 were analyzed. For every one-unit increase in OBS, the odds of wheezing/chronic bronchitis decreased by 6%. Increased OBS was associated with higher percent-predicted forced expiratory volume in one second (FEV1) (adjusted mean difference (MD), 0.21%; 95% CI: 0.10-0.32) and percent-predicted forced vital capacity (FVC) (adjusted MD, 0.15%; 95% CI: 0.07-0.24). A significantly lower risk of wheezing/chronic bronchitis was found in participants in the second/third/fourth OBS quartile compared to those in the first OBS quartile (all P for trend < 0.05). Moreover, higher percent-predicted FEV1 and FVC were also found in the third quartile and fourth quartile (all P for trend < 0.05). Furthermore, both dietary and lifestyle components were tightly related to pulmonary outcomes. Many associations were maintained after stratified by sex or after sensitivity analyses.

Conclusion

Oxidative balance score was negatively correlated with the diagnosis of chronic bronchitis/wheezing/restrictive spirometry pattern and positively correlated with percent-predicted FVC and FEV1. It seems that the higher the OBS score, the better the pulmonary outcomes. The findings highlight the importance of adherence to an antioxidant diet and lifestyle and that it contributes to lung health.

Ascorbate Is a Primary Antioxidant in Mammals

Ascorbate (vitamin C in primates) functions as a cofactor for a number of enzymatic reactions represented by prolyl hydroxylases and as an antioxidant due to its ability to donate electrons, which is mostly accomplished through non-enzymatic reaction in mammals. Ascorbate directly reacts with radical species and is converted to ascorbyl radical followed by dehydroascorbate. Ambiguities in physiological relevance of ascorbate observed during in vivo situations could be attributed in part to presence of other redox systems and the pro-oxidant properties of ascorbate. Most mammals are able to synthesize ascorbate from glucose, which is also considered to be an obstacle to verify its action. In addition to animals with natural deficiency in the ascorbate synthesis, such as guinea pigs and ODS rats, three strains of mice with genetic removal of the responsive genes (GULO, RGN, or AKR1A) for the ascorbate synthesis have been established and are being used to investigate the physiological roles of ascorbate. Studies using these mice, along with ascorbate transporter (SVCT)-deficient mice, largely support its ability in protection against oxidative insults. While combined actions of ascorbate in regulating epigenetics and antioxidation appear to effectively prevent cancer development, pharmacological doses of ascorbate and dehydroascorbate may exert tumoricidal activity through redox-dependent mechanisms.

Intravenous Ascorbic Acid and Lung Function in Severely IllCOVID-19 Patients

Current evidence suggests that ascorbic acid improves the host’s immune system and, therefore, may play a role in reducing the severity of infectious diseases. Coronavirus disease 2019 (COVID-19) is a potentially life-threatening viral infection that mainly infects the lungs. The objective of this review was to synthesize the existing findings from studies related to the effect of intravenous ascorbic acid on lung function in COVID-19 patients. For this review, PubMed, Cochrane, SCOPUS, EMBASE, Clinical Trial Registry, and Google Scholar databases were searched from December 2019 to May 2022. There was a total of six studies that investigated the large dose of ascorbic acid infusion intravenously on lung function in severely ill subjects with COVID-19. Out of six, three studies found that high-dose intravenous ascorbic acid improved lung function markers, and three studies found null results. Infusions of 12 g/d and 24 g/d of intravenous ascorbic acid had shown a significant improvement in lung function markers in two clinical trials. Studies that administered 8 g/d, 2 g/d, and 50 mg/kg/d of intravenous ascorbic acid found no influence on mechanical ventilation need and other lung function markers in critically ill subjects with COVID-19. Overall, the effect of intravenous ascorbic acid on the lung function of subjects with COVID yielded equivocal findings. More double-blinded, randomized, clinical studies with a larger sample size are required to confirm the effect of ascorbic acid in ameliorating the lung pathologies associated with COVID infection.

Serum antioxidant vitamins and respiratory morbidity and mortality: a pooled analysis

BACKGROUND

Oxidative stress plays a key role in the pathogenesis of respiratory diseases; however, studies on antioxidant vitamins and respiratory outcomes have been conflicting. We evaluated whether lower serum levels of vitamins A, C, D, and E are associated with respiratory morbidity and mortality in the U.S. adult population.

METHODS

We conducted a pooled analysis of data from the 1988-1994 and 1999-2006 National Health and Nutrition Examination Survey (participants aged ≥ 20 years). We estimated covariate-adjusted odds ratios (aOR) per interquartile decrease in each serum vitamin level to quantify associations with respiratory morbidity, and covariate-adjusted hazard ratios (aHR) to quantify associations with respiratory mortality assessed prospectively through 2015. Vitamin supplementation and smoking were evaluated as potential effect modifiers.

RESULTS

Lower serum vitamin C increased the odds of wheeze among all participants (overall aOR: 1.08, 95% CI: 1.01-1.16). Among smokers, lower serum α-tocopherol vitamin E increased the odds of wheeze (aOR: 1.11, 95% CI: 1.04-1.19) and chronic bronchitis/emphysema (aOR: 1.13, 95% CI: 1.03-1.24). Conversely, lower serum γ-tocopherol vitamin E was associated with lower odds of wheeze and chronic bronchitis/emphysema (overall aORs: 0.85, 95% CI: 0.79-0.92 and 0.85, 95% CI: 0.76-0.95, respectively). Lower serum vitamin C was associated with increased chronic lower respiratory disease (CLRD) mortality in all participants (overall aHR: 1.27, 95% CI: 1.07-1.51), whereas lower serum 25-hydroxyvitamin D (25-OHD) tended to increase mortality from CLRD and influenza/pneumonia among smokers (aHR range: 1.33-1.75). Mortality from influenza/ pneumonia increased with decreasing serum vitamin A levels in all participants (overall aHR: 1.21, 95% CI: 0.99-1.48). In pooled analysis, vitamin C deficiency and 25-OHD insufficiency were associated with mortality from influenza/pneumonia, increasing mortality risk up to twofold.

CONCLUSIONS

Our analysis of nationally representative data on over 34,000 participants showed that lower serum levels of vitamins A, C, D, and α-tocopherol vitamin E are associated with increased respiratory morbidity and/or mortality in U.S. adults. The results underscore the importance of antioxidant vitamins in respiratory health.

Chronic obstructive pulmonary disease and atherosclerosis: common mechanisms and novel therapeutics

Chronic obstructive pulmonary disease (COPD) and atherosclerosis are chronic irreversible diseases, that share a number of common causative factors including cigarette smoking. Atherosclerosis drastically impairs blood flow and oxygen availability to tissues, leading to life-threatening outcomes including myocardial infarction (MI) and stroke. Patients with COPD are most likely to die as a result of a cardiovascular event, with 30% of all COPD-related deaths being attributed to cardiovascular disease (CVD). Both atherosclerosis and COPD involve significant local (i.e. lung, vasculature) and systemic inflammation and oxidative stress, of which current pharmacological treatments have limited efficacy, hence the urgency for the development of novel life-saving therapeutics. Currently these diseases must be treated individually, with no therapies available that can effectively reduce the likelihood of comorbid CVD other than cessation of cigarette smoking. In this review, the important mechanisms that drive atherosclerosis and CVD in people with COPD are explained and we propose that modulation of both the oxidative stress and the inflammatory burden will provide a novel therapeutic strategy to treat both the pulmonary and systemic manifestations related to these diseases.

Molecular regulation of lung maturation in near-term fetal sheep by maternal daily vitamin C treatment in late gestation

BACKGROUND

In the fetus, the appropriate balance of prooxidants and antioxidants is essential to negate the detrimental effects of oxidative stress on lung maturation. Antioxidants improve respiratory function in postnatal life and adulthood. However, the outcomes and biological mechanisms of antioxidant action in the fetal lung are unknown.

METHODS

We investigated the effect of maternal daily vitamin C treatment (200 mg/kg, intravenously) for a month in late gestation (105-138 days gestation, term ~145 days) on molecular regulation of fetal lung maturation in sheep. Expression of genes and proteins regulating lung development was quantified in fetal lung tissue. The number of surfactant-producing cells was determined by immunohistochemistry.

RESULTS

Maternal vitamin C treatment increased fetal lung gene expression of the antioxidant enzyme SOD-1, hypoxia signaling genes (HIF-2α, HIF-3α, ADM, and EGLN-3), genes regulating sodium movement (SCNN1-A, SCNN1-B, ATP1-A1, and ATP1-B1), surfactant maturation (SFTP-B and ABCA3), and airway remodeling (ELN). There was no effect of maternal vitamin C treatment on the expression of protein markers evaluated or on the number of surfactant protein-producing cells in fetal lung tissue.

CONCLUSIONS

Maternal vitamin C treatment in the last third of pregnancy in sheep acts at the molecular level to increase the expression of genes that are important for fetal lung maturation in a healthy pregnancy.

IMPACT

Maternal daily vitamin C treatment for a month in late gestation in sheep increases the expression of gene-regulating pathways that are essential for normal fetal lung development. Following late gestation vitamin C exposure in a healthy pregnancy, an increase in lung gene but not protein expression may act as a mechanism to aid in the preparation for exposure to the air-breathing environment after birth. In the future, the availability/development of compounds with greater antioxidant properties than vitamin C or more specific targets at the site of oxidative stress in vivo may translate clinically to improve respiratory outcomes in complicated pregnancies at birth.

Whole genome sequence analysis of pulmonary function and COPD in 19,996 multi-ethnic participants

Chronic obstructive pulmonary disease (COPD), diagnosed by reduced lung function, is a leading cause of morbidity and mortality. We performed whole genome sequence (WGS) analysis of lung function and COPD in a multi-ethnic sample of 11,497 participants from population- and family-based studies, and 8499 individuals from COPD-enriched studies in the NHLBI Trans-Omics for Precision Medicine (TOPMed) Program. We identify at genome-wide significance 10 known GWAS loci and 22 distinct, previously unreported loci, including two common variant signals from stratified analysis of African Americans. Four novel common variants within the regions of PIAS1, RGN (two variants) and FTO show evidence of replication in the UK Biobank (European ancestry n ~ 320,000), while colocalization analyses leveraging multi-omic data from GTEx and TOPMed identify potential molecular mechanisms underlying four of the 22 novel loci. Our study demonstrates the value of performing WGS analyses and multi-omic follow-up in cohorts of diverse ancestry.

Effect of Intravenous Injection of Vitamin C on Postoperative Pulmonary Complications in Patients Undergoing Cardiac Surgery: A Double-Blind, Randomized Trial

Purpose

In this study, the effect of intravenous vitamin C during surgery on the incidence of postoperative pulmonary complications (PPCs) in patients undergoing cardiopulmonary bypass and cardiac surgery was observed, and its protective effect on the lungs was evaluated to provide a reference for clinical medication.

Patients and Methods

Patients undergoing cardiac surgery under cardiopulmonary bypass (CPB) were selected. The patients were divided into group A and group C by random sequence. Patients in group A received intravenous vitamin C 1 g 10 minutes after induction of anesthesia, 10 minutes before cardiac reanimation and at the moment of sternal closure. Patients in group C were intravenously injected with the same volume of saline at the same time. The primary outcome was the postoperative pulmonary complication severity score. Other outcomes were the incidence of PPCs, awakening time, extubation time, length of ICU stay, length of hospital stay, adverse events, oxygenation index (PaO₂/FiO₂), alveolar arterial oxygen partial pressure difference (A-aDO₂), dynamic lung compliance (Cd) and static lung compliance (Cs).

Results

Seventy patients completed the study. Compared to group C, the postoperative pulmonary complication score [2(2–3) vs 2(1–2); P=0.009] and the incidence of postoperative pulmonary complications (32.43% vs 12.12%; P =0.043) were lower in group A. There were no significant differences in awakening time, extubation time, length of ICU stay, length of hospital stay, adverse events, PaO₂/FiO₂, A-aDO₂, Cs, and Cd between the two groups (P>0.05).

Conclusion

In summary, this small randomized trial including low-risk cardiac surgery patients shows that intravenous vitamin C may safely be administered and may be helpful to prevent PPCs after cardiac surgery.

p19Arf Exacerbates Cigarette Smoke-Induced Pulmonary Dysfunction

Senescent cells accumulate in tissues during aging or pathological settings. The semi-genetic or pharmacological targeting of senescent cells revealed that cellular senescence underlies many aspects of the aging-associated phenotype and diseases. We previously reported that cellular senescence contributes to aging- and disease-associated pulmonary dysfunction. We herein report that the elimination of Arf-expressing cells ameliorates cigarette smoke-induced lung pathologies in mice. Cigarette smoke induced the expression of Ink4a and Arf in lung tissue with concomitant increases in lung tissue compliance and alveolar airspace. The elimination of Arf-expressing cells prior to cigarette smoke exposure protected against these changes. Furthermore, the administration of cigarette smoke extract lead to pulmonary dysfunction, which was ameliorated by subsequent senescent cell elimination. Collectively, these results suggest that senescent cells are a potential therapeutic target for cigarette smoking-associated lung disease.

The Beneficial Effects of Antioxidants in Health And Diseases

Reactive oxygen and nitrogen species can be generated endogenously (by mitochondria, peroxisomes, and phagocytic cells) and exogenously (by pollutions, UV exposure, xenobiotic compounds, and cigarette smoke). The negative effects of free radicals are neutralized by antioxidant molecules synthesized in our body, like glutathione, uric acid, or ubiquinone, and those obtained from the diet, such as vitamins C, E, and A, and flavonoids. Different microelements like selenium and zinc have no antioxidant action themselves but are required for the activity of many antioxidant enzymes. Furthermore, circulating blood proteins are suggested to account for more than 50% of the combined antioxidant effects of urate, ascorbate, and vitamin E. Antioxidants together constitute a mutually supportive defense against reactive oxygen and nitrogen species to maintain the oxidant/antioxidant balance. This article outlines the oxidative and anti-oxidative molecules involved in the pathogenesis of chronic obstructive lung disease. The role of albumin and alpha-1 antitrypsin in antioxidant defense is also discussed.

Plasma vitamin C concentrations and risk of incident respiratory diseases and mortality in the European Prospective Investigation into Cancer-Norfolk population-based cohort study

BACKGROUND/OBJECTIVES

Cancerous and non-cancerous respiratory diseases are common and contribute significantly to global disease burden. We aim to quantify the association between plasma vitamin C concentrations as an indicator of high fruit and vegetable consumption and the risk of incident respiratory diseases and associated mortality in a general population.

SUBJECTS/METHODS

Nineteen thousand three hundred and fifty-seven men and women aged 40-79 years without prevalent respiratory diseases at the baseline (1993-1997) and participating in the European Prospective Investigation into Cancer (EPIC)-Norfolk study in the United Kingdom were followed through March 2015 for both incidence and mortality from respiratory diseases.

RESULTS

There were a total of 3914 incident events and 407 deaths due to any respiratory diseases (excluding lung cancers), 367 incident lung cancers and 280 lung cancer deaths during the follow-up (total person-years >300,000 years). Cox's proportional hazards models showed that persons in the top quartiles of baseline plasma vitamin C concentrations had a 43% lower risk of lung cancer (hazard ratio (HR) 0.57; 95% confidence interval (CI): 0.41-0.81) than did those in the bottom quartile, independently of potential confounders. The results are similar for any non-cancerous respiratory diseases (HR 0.85; 0.77-0.95), including chronic respiratory diseases (HR 0.81; 0.69-0.96) and pneumonia (HR 0.70; 0.59-0.83). The corresponding values for mortality were 0.54 (0.35-0.81), 0.81 (0.59-1.12), 0.85 (0.44-1.66) and 0.61 (0.37-1.01), respectively. Confining analyses to non-smokers showed 42% and 53% risk reduction of non-smoking-related lung cancer incidence and death.

CONCLUSIONS

Higher levels of vitamin C concentrations as a marker of high fruit and vegetable consumption reduces the risk of cancerous and non-cancerous respiratory illnesses including non-smoking-related cancer incidence and deaths.

Regional heterogeneity in response of airway epithelial cells to cigarette smoke

Background

Cigarette smoke (CS) exposure causes an abnormal inflammatory response, which can result in chronic obstructive pulmonary disease (COPD). Previous studies show that this disorder predominantly occurs in peripheral or small-airway areas, whereas the same condition has not been identified in the larger airways during the course of COPD. However, the different biochemical and genetic alterations occurring in response to CS exposure among airway epithelial cells from different sites in the lungs have not been fully investigated.

Methods

Human small airway epithelial cells (SAECs) and normal human bronchial epithelial cells (NHBEs) were exposed to CS extract (CSE), and microarray analysis was used to determine gene- and protein-expression profiles and identify alterations following CSE exposure in both cell types. An in vivo smoking experiment was also performed to confirm differential responses to CS between sites in the lung.

Results

Microarray analysis of SAECs and NHBEs following 24 h of CSE exposure showed that inflammatory related pathways and terms, including the tumor necrosis factor-signaling pathway, were overrepresented, especially in SAECs. Clustering analysis highlighted prostaglandin-endoperoxide synthase-2 [also known as cyclooxygenase (COX)-2] as a gene specifically upregulated in SAECs, with COX-2 mRNA and protein expression significantly elevated by CSE exposure in SAECs (3.1- and 3.1-fold, respectively), but not in NHBEs. Furthermore, time-course analysis of COX-2 expression revealed earlier increases in SAECs compared with NHBEs following CS exposure. Short-term exposure of mouse lungs to CS was found to predominantly induce COX-2 expression in the small airway.

Conclusions

The small airway is more susceptible to CSE than the large airway and could be the initial site of development of CS-related respiratory diseases, such as COPD.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0715-4) contains supplementary material, which is available to authorized users.

Combination of urea-crosslinked hyaluronic acid and sodium ascorbyl phosphate for the treatment of inflammatory lung diseases: An in vitro study

This in vitro study evaluated, for the first time, the safety and the biological activity of a novel urea-crosslinked hyaluronic acid component and sodium ascorbyl phosphate (HA-CL - SAP), singularly and/or in combination, intended for the treatment of inflammatory lung diseases. The aim was to understand if the combination HA-CL - SAP had an enhanced activity with respect to the combination native hyaluronic acid (HA) - SAP and the single SAP, HA and HA-CL components. Sample solutions displayed pH, osmolality and viscosity values suitable for lung delivery and showed to be not toxic on epithelial Calu-3 cells at the concentrations used in this study. The HA-CL - SAP displayed the most significant reduction in interleukin-6 (IL-6) and reactive oxygen species (ROS) levels, due to the combined action of HA-CL and SAP. Moreover, this combination showed improved cellular healing (wound closure) with respect to HA - SAP, SAP and HA, although at a lower rate than HA-CL alone. These preliminary results showed that the combination HA-CL - SAP could be suitable to reduce inflammation and oxidative stress in lung disorders like acute respiratory distress syndrome, asthma, emphysema and chronic obstructive pulmonary disease, where inflammation is prominent.

Effects of dietary antioxidant vitamins on lung functions according to gender and smoking status in Korea: a population-based cross-sectional study

OBJECTIVE

Cigarette smoke-induced oxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Dietary antioxidants are thought to prevent smoke-induced oxidative damage. The aim of this study was to investigate associations between lung function and the consumption of antioxidant vitamins in Korean adults.

METHODS

In total, 21 148 participants from the Korean National Health and Nutrition Examination Survey (2007-2014) were divided into four groups based on smoking history and gender. Multivariate regression models were used to evaluate associations between lung function and intake of dietary antioxidants.

RESULTS

Subjects in the highest intake quintile (Q5) of vitamin A, carotene and vitamin C intake had mean forced expiratory volume in 1 s (FEV₁) measurements that were 30 mL, 32 mL and 36 mL higher than those of individuals in the lowest intake quintile (Q1), respectively (p for trend; p=0.008, p=0.010 and p<0.001, respectively). The risks of COPD for male smokers in Q1 increased 7.60-fold (95% CI 5.92 to 9.76), 7.16-fold (95% CI 5.58 to 9.19) and 7.79-fold (95% CI 6.12 to 9.92), for vitamin A, carotene and vitamin C, respectively, compared with those of female non-smokers in Q5. Among patients with COPD, men who smoked >20 pack-years had mean FEV₁ measurements that were 192 mL, 149 mL and 177 mL higher than those of patients in Q1 (p for trend; p=0.018, p=0.024 and p=0.043, for vitamin A, carotene and vitamin C, respectively).

CONCLUSIONS

These findings indicate that the influence of antioxidant vitamins on lung function depends on gender and smoking status in the Korean COPD population.

Hydrogen-rich pure water prevents cigarette smoke-induced pulmonary emphysema in SMP30 knockout mice

Chronic obstructive pulmonary disease (COPD) is predominantly a cigarette smoke (CS)-triggered disease with features of chronic systemic inflammation. Oxidants derived from CS can induce DNA damage and stress-induced premature cellular senescence in the respiratory system, which play significant roles in COPD. Therefore, antioxidants should provide benefits for the treatment of COPD; however, their therapeutic potential remains limited owing to the complexity of this disease. Recently, molecular hydrogen (H₂) has been reported as a preventive and therapeutic antioxidant. Molecular H₂ can selectively reduce hydroxyl radical accumulation with no known side effects, showing potential applications in managing oxidative stress, inflammation, apoptosis, and lipid metabolism. However, there have been no reports on the efficacy of molecular H₂ in COPD patients. In the present study, we used a mouse model of COPD to investigate whether CS-induced histological damage in the lungs could be attenuated by administration of molecular H₂. We administered H₂-rich pure water to senescence marker protein 30 knockout (SMP30-KO) mice exposed to CS for 8 weeks. Administration of H₂-rich water attenuated the CS-induced lung damage in the SMP30-KO mice and reduced the mean linear intercept and destructive index of the lungs. Moreover, H₂-rich water significantly restored the static lung compliance in the CS-exposed mice compared with that in the CS-exposed H₂-untreated mice. Moreover, treatment with H₂-rich water decreased the levels of oxidative DNA damage markers such as phosphorylated histone H2AX and 8-hydroxy-2'-deoxyguanosine, and senescence markers such as cyclin-dependent kinase inhibitor 2A, cyclin-dependent kinase inhibitor 1, and β-galactosidase in the CS-exposed mice. These results demonstrated that H₂-rich pure water attenuated CS-induced emphysema in SMP30-KO mice by reducing CS-induced oxidative DNA damage and premature cell senescence in the lungs. Our study suggests that administration of molecular H₂ may be a novel preventive and therapeutic strategy for COPD.

Anti-p-benzoquinone antibody level as a prospective biomarker to identify smokers at risk for COPD

Background and objective

Identification of smokers having predisposition to COPD is important for early intervention to reduce the huge global burden of the disease. Using a guinea pig model, we have shown that p-benzoquinone (p-BQ) derived from cigarette smoke (CS) in the lung is a causative factor for CS-induced emphysema. p-BQ is also derived from CS in smokers and it elicits the production of anti-p-BQ antibody in humans. We therefore hypothesized that anti-p-BQ antibody might have a protective role against COPD and could be used as a predictive biomarker for COPD in smokers. The objective of this study was to compare the serum anti-p-BQ antibody level between smokers with and without COPD for the evaluation of the hypothesis.

Methods

Serum anti-p-BQ antibody concentrations of current male smokers with (n=227) or without (n=308) COPD were measured by an indirect enzyme-linked immunoabsorbent assay (ELISA) developed in our laboratory. COPD was diagnosed by spirometry according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines.

Results and discussion

A significant difference was observed in the serum anti-p-BQ antibody level between smokers with and without COPD (Mann–Whitney U-test =4,632.5, P=0.000). Receiver operating characteristic (ROC) curve analysis indicated that the ELISA had significant precision (area under the curve [AUC] =0.934, 95% confidence interval [CI]: 0.913–0.935) for identifying smokers with COPD from their low antibody level. The antibody cutoff value of 29.4 mg/dL was constructed from the ROC coordinates to estimate the risk for COPD in smokers. While 90.3% of smokers with COPD had a low antibody value (≤29.4 mg/dL), the majority (86.4%) of smokers without COPD had a high antibody value (≤29.4 mg/dL); 13.6% of current smokers without COPD having an antibody level below this cutoff value (odds ratio [OR] =59.3, 95% CI: 34.15–101.99) were considered to be at risk for COPD.

Conclusion and future directions

Our results indicate that serum anti-p-BQ antibody level may be used as a biomarker to identify asymptomatic smokers at risk for COPD for early intervention of the disease.

Acerola (Malpighia emarginata DC.) Juice Intake Suppresses UVB-Induced Skin Pigmentation in SMP30/GNL Knockout Hairless Mice

BACKGROUND/AIMS

Acerola (Malpighia emarginata DC.) is a fruit that is known to contain high amounts of ascorbic acid (AA) and various phytochemicals. We have previously reported that AA deficiency leads to ultraviolet B (UVB)-induced skin pigmentation in senescence marker protein 30 (SMP30)/gluconolactonase (GNL) knockout (KO) hairless mice. The present study was undertaken to investigate the effects of acerola juice (AJ) intake on the skin of UVB-irradiated SMP30/GNL KO mice.

RESEARCH DESIGN/PRINCIPAL FINDINGS

Five-week old hairless mice were given drinking water containing physiologically sufficient AA (1.5 g/L) [AA (+)], no AA [AA (-)] or 1.67% acerola juice [AJ]. All mice were exposed to UVB irradiation for 6 weeks. UVB irradiation was performed three times per week. The dorsal skin color and stratum corneum water content were measured every weekly, and finally, the AA contents of the skin was determined. The skin AA and stratum corneum water content was similar between the AA (+) and AJ groups. The L* value of the AA (+) group was significantly decreased by UVB irradiation, whereas AJ intake suppressed the decrease in the L* value throughout the experiment. Moreover, in the AJ group, there was a significant decrease in the expression level of dopachrome tautomerase, an enzyme that is involved in melanin biosynthesis.

CONCLUSION

These results indicate that AJ intake is effective in suppressing UVB-induced skin pigmentation by inhibiting melanogenesis-related genes.

Pharmacological and genetic reappraisals of protease and oxidative stress pathways in a mouse model of obstructive lung diseases

Protease-antiprotease imbalance and oxidative stress are considered to be major pathophysiological hallmarks of severe obstructive lung diseases including chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF), but limited information is available on their direct roles in the regulation of pulmonary phenotypes. Here, we utilized βENaC-transgenic (Tg) mice, the previously established mouse model of severe obstructive lung diseases, to produce lower-mortality but pathophysiologically highly useful mouse model by backcrossing the original line with C57/BL6J mice. C57/BL6J-βENaC-Tg mice showed higher survival rates and key pulmonary abnormalities of COPD/CF, including mucous hypersecretion, inflammatory and emphysematous phenotypes and pulmonary dysfunction. DNA microarray analysis confirmed that protease- and oxidative stress-dependent pathways are activated in the lung tissue of C57/BL6J-βENaC-Tg mice. Treatments of C57/BL6J-βENaC-Tg mice with a serine protease inhibitor ONO-3403, a derivative of camostat methylate (CM), but not CM, and with an anti-oxidant N-acetylcystein significantly improved pulmonary emphysema and dysfunction. Moreover, depletion of a murine endogenous antioxidant vitamin C (VC), by genetic disruption of VC-synthesizing enzyme SMP30 in C57/BL6J-βENaC-Tg mice, exaggerated pulmonary phenotypes. Thus, these assessments clarified that protease-antiprotease imbalance and oxidative stress are critical pathways that exacerbate the pulmonary phenotypes of C57/BL6J-βENaC-Tg mice, consistent with the characteristics of human COPD/CF.

Dietary vitamin C intake protects against COPD: the Korea National Health and Nutrition Examination Survey in 2012

BACKGROUND

Vitamin C, as an antioxidant, has recently been suggested to provide protection against COPD; however, only few national cohort studies have investigated these effects. We aimed to confirm the protective effects of vitamin C against COPD in Korean patients.

PATIENTS AND METHODS

We analyzed the data of 3,283 adults aged ≥40 years (representing 23,541,704 subjects) who underwent pulmonary function tests and responded to questionnaires on smoking history and vitamin C intake, with stratification variables and sampling weight designated by the Korea 2012 National Health and Nutrition Examination Survey.

RESULTS

Among all the subjects, 512 (representing 3,459,679 subjects; 15.6%) were diagnosed as having COPD based on pulmonary function test results. Male gender, old age, residence in suburban/rural regions, low household income, low educational level, an occupation in agriculture or fisheries, and heavy smoking were significantly associated with COPD. Low intake of nutrients, including potassium, vitamin A, carotene, retinol, and vitamin C, was significantly associated with COPD. The prevalence of COPD in heavy smokers with the lowest quartile (Q1, <48.50 mg; 63.0%) and low-middle quartile (Q2, 48.50-84.38 mg; 56.4%) of vitamin C intake was significantly higher than that in subjects with the high-middle quartile (Q3, 84.38-141.63 mg; 29.5%) and highest quartile (Q4, >141.63 mg; 32.6%) of vitamin C intake (P=0.015). In multivariate analysis, male gender, old age, heavy smoking, and a low intake of vitamin C were significant independent risk factors for COPD. A significant reduction of 76.7% in COPD risk was observed with a Q3 vitamin C intake compared to Q1 vitamin C intake (odds ratio, 0.233; 95% confidence interval, 0.094-0.576) in heavy smokers.

CONCLUSION

This large-scale national study suggests that dietary vitamin C provides protection against COPD, independent of smoking history, in the general Korean population.

Chronic Pseudomonas aeruginosa infection-induced chronic bronchitis and emphysematous changes in CCSP-deficient mice

The club cell secretory protein (CCSP) is a regulator of lung inflammation following acute respiratory infection or lung injury. Recently, the relationship between CCSP and COPD has been reported. Since COPD results from an abnormal inflammatory response, we hypothesized that CCSP could have a protective role against chronic inflammation-induced lung damage. To address this issue, the pathophysiology of chronic lung inflammation induced by Pseudomonas aeruginosa in CCSP-deficient mice was determined. A tube of 5 mm in length was soaked in a fluid containing P. aeruginosa (PAO01 strain) for 1 week and inserted into the trachea of CCSP-deficient mice. One week later, P. aeruginosa was administered into the trachea. Five weeks after insertion of tube, the mice were sacrificed. Bronchoalveolar lavage fluids were collected to determine the bacterial growth, and the lung histology and physiology were also examined. P. aeruginosa was continuously detected in bronchoalveolar lavage fluids during the study. Neutrophils were increased in the bronchoalveolar lavage fluids from the CCSP-deficient mice in comparison to wild-type mice. A histological study demonstrated chronic inflammation around bronchus, serious bronchial stenosis, and alveolar enlargement in the CCSP-deficient mice. The lung physiology study demonstrated an increase in the lung compliance of the CCSP-deficient mice. Chronic P. aeruginosa inflammation resulted in chronic bronchitis and emphysematous changes in the CCSP-deficient mice. CCSP could play an important role in protecting the host from the chronic inflammation-induced lung damage.

A Targeted Inhibitor of the Alternative Complement Pathway Accelerates Recovery From Smoke-Induced Ocular Injury

Purpose

Morphologic and genetic evidence exists that an overactive complement system driven by the complement alternative pathway (AP) is involved in pathogenesis of age-related macular degeneration (AMD). Smoking is the only modifiable risk factor for AMD. As we have shown that smoke-related ocular pathology can be prevented in mice that lack an essential activator of AP, we ask here whether this pathology can be reversed by increasing inhibition in AP.

Methods

Mice were exposed to either cigarette smoke (CS) or filtered air (6 hours/day, 5 days/week, 6 months). Smoke-exposed animals were then treated with the AP inhibitor (CR2-fH) or vehicle control (PBS) for the following 3 months. Spatial frequency and contrast sensitivity were assessed by optokinetic response paradigms at 6 and 9 months; additional readouts included assessment of retinal morphology by electron microscopy (EM) and gene expression analysis by quantitative RT-PCR.

Results

The CS mice treated with CR2-fH showed significant improvement in contrast threshold compared to PBS-treated mice, whereas spatial frequency was unaffected by CS or pharmacologic intervention. Treatment with CR2-fH in CS animals reversed thinning of the retina observed in PBS-treated mice as analyzed by spectral-domain optical coherence tomography, and reversed most morphologic changes in RPE and Bruch's membrane seen in CS animals by EM.

Conclusions

Taken together, these findings suggest that AP inhibitors not only prevent, but have the potential to accelerate the clearance of complement-mediated ocular injury. Improving our understanding of the regulation of the AP is paramount to developing novel treatment approaches for AMD.

Ascorbate attenuates pulmonary emphysema by inhibiting tobacco smoke and Rtp801-triggered lung protein modification and proteolysis

Cigarette smoking causes emphysema, a fatal disease involving extensive structural and functional damage of the lung. Using a guinea pig model and human lung cells, we show that oxidant(s) present in tobacco smoke not only cause direct oxidative damage of lung proteins, contributing to the major share of lung injury, but also activate Rtp801, a key proinflammatory cellular factor involved in tobacco smoke-induced lung damage. Rtp801 triggers nuclear factor κB and consequent inducible NOS (iNOS)-mediated overproduction of NO, which in combination with excess superoxide produced during Rtp801 activation, contribute to increased oxido-nitrosative stress and lung protein nitration. However, lung-specific inhibition of iNOS with a iNOS-specific inhibitor, N6-(1-iminoethyl)-L-lysine, dihydrochloride (L-NIL) solely restricts lung protein nitration but fails to prevent or reverse the major tobacco smoke-induced oxidative lung injury. In comparison, the dietary antioxidant, ascorbate or vitamin C, can substantially prevent such damage by inhibiting both tobacco smoke-induced lung protein oxidation as well as activation of pulmonary Rtp801 and consequent iNOS/NO-induced nitration of lung proteins, that otherwise lead to increased proteolysis of such oxidized or nitrated proteins by endogenous lung proteases, resulting in emphysematous lung damage. Vitamin C also restricts the up-regulation of matrix-metalloproteinase-9, the major lung protease involved in the proteolysis of such modified lung proteins during tobacco smoke-induced emphysema. Overall, our findings implicate tobacco-smoke oxidant(s) as the primary etiopathogenic factor behind both the noncellular and cellular damage mechanisms governing emphysematous lung injury and demonstrate the potential of vitamin C to accomplish holistic prevention of such damage.

Resolvin D1 prevents smoking-induced emphysema and promotes lung tissue regeneration

Purpose

Emphysema is an irreversible disease that is characterized by destruction of lung tissue as a result of inflammation caused by smoking. Resolvin D1 (RvD1), derived from docosahexaenoic acid, is a novel lipid that resolves inflammation. The present study tested whether RvD1 prevents smoking-induced emphysema and promotes lung tissue regeneration.

Materials and methods

C57BL/6 mice, 8 weeks of age, were randomly divided into four groups: control, RvD1 only, smoking only, and smoking with RvD1 administration. Four different protocols were used to induce emphysema and administer RvD1: mice were exposed to smoking for 4 weeks with poly(I:C) or to smoking only for 24 weeks, and RvD1 was injected within the smoking exposure period to prevent regeneration or after completion of smoking exposure to assess regeneration. The mean linear intercept and inflammation scores were measured in the lung tissue, and inflammatory cells and cytokines were measured in the bronchoalveolar lavage fluid.

Results

Measurements of mean linear intercept showed that RvD1 significantly attenuated smoking-induced lung destruction in all emphysema models. RvD1 also reduced smoking-induced inflammatory cell infiltration, which causes the structural derangements observed in emphysema. In the 4-week prevention model, RvD1 reduced the smoking-induced increase in eosinophils and interleukin-6 in the bronchoalveolar lavage fluid. In the 24-week prevention model, RvD1 also reduced the increased neutrophils and total cell counts induced by smoking.

Conclusion

RvD1 attenuated smoking-induced emphysema in vivo by reducing inflammation and promoting tissue regeneration. This result suggests that RvD1 may be useful in the prevention and treatment of emphysema.

Protective effects of acerola juice on genotoxicity induced by iron in vivo

Metal ions such as iron can induce DNA damage by inducing reactive oxygen species (ROS) and oxidative stress. Vitamin C is one of the most widely consumed antioxidants worldwide, present in many fruits and vegetables, especially inMalpighia glabra L., popularly known as acerola, native to Brazil. Acerola is considered a functional fruit due to its high antioxidant properties and phenolic contents, and therefore is consumed to prevent diseases or as adjuvant in treatment strategies. Here, the influence of ripe and unripe acerola juices on iron genotoxicity was analyzed in vivo using the comet assay and micronucleus test. The comet assay results showed that acerola juice exerted no genotoxic or antigenotoxic activity. Neither ripe nor unripe acerola juices were mutagenic to animals treated with juices, in micronucleus test. However, when compared to iron group, the pre-treatment with acerola juices exerted antimutagenic activity, decreasing significantly micronucleus mean values in bone marrow. Stage of ripeness did not influence the interaction of acerola compounds with DNA, and both ripe and unripe acerola juices exerted protective effect over DNA damage generated by iron.

Nutrition and respiratory health--feature review

Diet and nutrition may be important modifiable risk factors for the development, progression and management of obstructive lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). This review examines the relationship between dietary patterns, nutrient intake and weight status in obstructive lung diseases, at different life stages, from in-utero influences through childhood and into adulthood. In vitro and animal studies suggest important roles for various nutrients, some of which are supported by epidemiological studies. However, few well-designed human intervention trials are available to definitively assess the efficacy of different approaches to nutritional management of respiratory diseases. Evidence for the impact of higher intakes of fruit and vegetables is amongst the strongest, yet other dietary nutrients and dietary patterns require evidence from human clinical studies before conclusions can be made about their effectiveness.

Short-term cigarette smoke exposure leads to metabolic alterations in lung alveolar cells

Cigarette smoke (CS)-induced alveolar destruction and energy metabolism changes are known contributors to the pathophysiology of chronic obstructive pulmonary disease (COPD). This study examines the effect of CS exposure on metabolism in alveolar type II cells. Male A/J mice (8 wk old) were exposed to CS generated from a smoking machine for 4 or 8 weeks, and a recovery group was exposed to CS for 8 weeks and allowed to recover for 2 weeks. Alveolar type II cells were isolated from air- or CS- exposed mice. Acute CS exposure led to a reversible airspace enlargement in A/J mice as measured by the increase in mean linear intercept, indicative of alveolar destruction. The effect of CS exposure on cellular respiration was studied using the XF Extracellular Flux Analyzer. A decrease in respiration while metabolizing glucose was observed in the CS-exposed group, indicating altered glycolysis that was compensated by an increase in palmitate utilization; palmitate utilization was accompanied by an increase in the expression of CD36 and carnitine-palmitoyl transferase 1 in type II alveolar cells for the transport of palmitate into the cells and into mitochondria, respectively. The increase in palmitate use for energy production likely affects the surfactant biosynthesis pathway, as evidenced by the decrease in phosphatidylcholine levels and the increase in phospholipase A2 activity after CS exposure. These findings help our understanding of the mechanism underlying the surfactant deficiency observed in smokers and provide a target to delay the onset of COPD.