ascorbic-acid and Asthma

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.

Topics: Animals; Ascorbic Acid; Asthma; Lung Neoplasms; Pneumonia; Pulmonary Disease, Chronic Obstructive; Respiratory Tract Diseases; Vitamins

Obesity in asthmatic patients has important relationships with asthma control, pulmonary function, and quality of life. The objective of this study was to conduct a systematic review of the literature on the effect of diet on asthma management in adults.. We searched PubMed, Embase, and Scopus (January 1948-October 2014) for randomized clinical trials that evaluated the effects of diet in adults with asthma.. Of 12,215 studies identified, 21 were included. A reduction in weight of at least 7.5% from baseline as a result of caloric restriction can be beneficial for improving disease control, quality of life, and pulmonary function in obese patients with asthma. A dietary pattern rich in foods with potential antioxidant effect had an impact in improving asthma control, but with little clinical significance. Studies involving antioxidant supplementation showed improvements in asthma control with magnesium supplementation and less decline in lung function with vitamin C supplementation. Studies of fatty acid supplementation demonstrated effects on weight loss and improvement of asthma control and lung function. Studies of supplementation with propolis and caffeine reported significant increases in FEV1. Conversely, studies of high dietary salt intake reported greater declines in lung function.. The evidence shows that, for obese adults with asthma, the best dietary intervention seems to be caloric restriction, regardless of specific dietary components.

Topics: Antioxidants; Ascorbic Acid; Asthma; Caloric Restriction; Diet; Dietary Supplements; Fatty Acids; Humans; Lung; Micronutrients; Obesity; Quality of Life; Randomized Controlled Trials as Topic; Weight Loss

Maternal smoking during pregnancy is the largest preventable cause of abnormal in-utero lung development. Despite well known risks, rates of smoking during pregnancy have only slightly decreased over the last ten years, with rates varying from 5-40% worldwide resulting in tens of millions of fetal exposures. Despite multiple approaches to smoking cessation about 50% of smokers will continue to smoke during pregnancy. Maternal genotype plays an important role in the likelihood of continued smoking during pregnancy and the degree to which maternal smoking will affect the fetus. The primary effects of maternal smoking on offspring lung function and health are decreases in forced expiratory flows, decreased passive respiratory compliance, increased hospitalization for respiratory infections, and an increased prevalence of childhood wheeze and asthma. Nicotine appears to be the responsible component of tobacco smoke that affects lung development, and some of the effects of maternal smoking on lung development can be prevented by supplemental vitamin C. Because nicotine is the key agent for affecting lung development, e-cigarette usage during pregnancy is likely to be as dangerous to fetal lung development as is maternal smoking.

Topics: Animals; Antioxidants; Ascorbic Acid; Asthma; Child; Disease Models, Animal; Epigenesis, Genetic; Female; Humans; Infant, Newborn; Lung; Nicotine; Nicotinic Agonists; Pregnancy; Prenatal Exposure Delayed Effects; Respiratory Tract Diseases; Smoking; Tobacco Smoke Pollution

Epidemiology of bronchial asthma (BA) indicates a marked paradox: rapid rise in the prevalence.Simultaneous decline in mortality is mostly related to improvement in the diagnosis and therapy. In many economically developed countries the BA affects more than 10 per cent of the population, while mortality related to this respiratory disorder is below 1/100,000. Factors favorably influencing mortality of BA include new more effective medications, decline in smoking and also improved nutrition, based on awareness of protective role of vitamins. Vitamin D deficiency has a number of biological effects that are potentially instrumental in the pathogenesis and severity of BA. Increased number of randomized, controlled, interventional studies is showing positive effects of vitamin D supplementation in pediatric and in adult BA. Oxidative stress is potentially an important pathogenic factor in the progression of BA. Vitamin C (ascorbic acid) belongs to the most effective nutritional antioxidants. By counteracting oxidants, reducing generation of reactive oxygen species, vitamin C may inhibit external attacks in the respiratory tract, thus modulating the development of BA (Fig. 2, Ref. 15).

Topics: Adult; Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Asthma; Child; Dietary Supplements; Humans; Oxidative Stress; Smoking; Vitamin D; Vitamin D Deficiency; Vitamins

The association between dietary antioxidants and asthma or exercise-induced bronchoconstriction (EIB) is not fully understood. Vitamin C and vitamin E are natural antioxidants that are predominantly present in fruits and vegetables; inadequate vitamin E intake is associated with airway inflammation. It has been postulated that the combination may be more beneficial than either single antioxidant for people with asthma and exercise-induced bronchoconstriction.. To assess the effects of supplementation of vitamins C and E versus placebo (or no vitamin C and E supplementation) on exacerbations and health-related quality of life (HRQL) in adults and children with chronic asthma. To also examine the potential effects of vitamins C and E on exercise-induced bronchoconstriction in people with asthma and in people without a diagnosis of asthma who experience symptoms only on exercise.. Trials were identified from the Cochrane Airways Review Group Specialised Register and from trial registry websites. Searches were conducted in September 2013.. We included randomised controlled trials of adults and children with a diagnosis of asthma. We separately considered trials in which participants had received a diagnosis of exercise-induced bronchoconstriction (or exercise-induced asthma). Trials comparing vitamin C and E supplementation versus placebo were included. We included trials in which asthma management for treatment and control groups included similar background therapy. Short-term use of vitamins C and E at the time of exacerbation or for cold symptoms in people with asthma is outside the scope of this review.. Two review authors independently screened the titles and abstracts of potential studies and subsequently screened full-text study reports for inclusion. We used standard methods as expected by The Cochrane Collaboration.. It was not possible to aggregate the five included studies (214 participants). Four studies (206 participants) addressed the question of whether differences in outcomes were seen when vitamin C and E supplementation versus placebo was provided for participants with asthma, and only one of those studies (160 children) included a paediatric population; the remaining three studies included a combined total of just 46 adults. An additional study considered the question of whether differences in outcomes were noted when vitamin C and E supplementation was compared with placebo for exercise-induced asthma; this trial included only eight participants. The randomisation process of the trials were unclear leading us to downgrade the quality of the evidence. Four of the studies were double blind while the other study was single blind.None of these studies provided data on our two prespecified primary outcome measures: exacerbations and HRQL. Lung function data obtained from the studies were inconclusive. The only studies that provided any suggestion of an effect, and only with some outcomes, were the paediatric study, especially for children with moderate to severe asthma, and the small study on exercise-induced asthma. Even so, this evidence was judged to be at moderate/low quality. Only one study contributed data on asthma symptoms and adverse events, reporting no evidence of an effect of the intervention for symptoms and that one participant in the treatment group dropped out due to cystitis.. It is not possible to draw firm conclusions from this review with respect to the comparison of vitamin C and E supplementation versus placebo in the management of asthma or exercise-induced bronchoconstriction. We found only one study relevant to exercise-induced bronchoconstriction; most included participants came from studies designed to assess the effect of vitamin supplementation on the impact of atmospheric pollutants (such as ozone). Evidence is lacking on the comparison of vitamin C and E supplementation versus placebo for asthma with respect to outcomes such as HRQL and exacerbations, which were not addressed by any of the included studies.When compared with lung function tests alone, HRQL scores and exacerbation frequency are better indicators of the severity of asthma, its impact on daily activities and its response to treatment in a patient population. These end points are well recognised in good quality studies of asthma management. However, clinical studies of vitamins C and E in the management of asthma using these important end points of exacerbations and effects on quality of life are not available, and evidence is insufficient to support robust conclusions on the role of vitamin C and E supplementation in asthma and exercise-induced breathlessness.

Topics: Adult; Antioxidants; Ascorbic Acid; Asthma; Asthma, Exercise-Induced; Bronchoconstriction; Child; Chronic Disease; Exercise; Humans; Randomized Controlled Trials as Topic; Vitamins

Dietary antioxidants, such as vitamin C, in the epithelial lining and lining fluids of the lung may be beneficial in the reduction of oxidative damage (Arab 2002). They may therefore be of benefit in reducing symptoms of inflammatory airway conditions such as asthma, and may also be beneficial in reducing exercise-induced bronchoconstriction, which is a well-recognised feature of asthma and is considered a marker of airways inflammation. However, the association between dietary antioxidants and asthma severity or exercise-induced bronchoconstriction is not fully understood.. To examine the effects of vitamin C supplementation on exacerbations and health-related quality of life (HRQL) in adults and children with asthma or exercise-induced bronchoconstriction compared to placebo or no vitamin C.. We identified trials from the Cochrane Airways Group's Specialised Register (CAGR). The Register contains trial reports identified through systematic searches of a number of bibliographic databases, and handsearching of journals and meeting abstracts. We also searched trial registry websites. The searches were conducted in December 2012.. We included randomised controlled trials (RCTs). We included both adults and children with a diagnosis of asthma. In separate analyses we considered trials with a diagnosis of exercise-induced bronchoconstriction (or exercise-induced asthma). We included trials comparing vitamin C supplementation with placebo, or vitamin C supplementation with no supplementation. We included trials where the asthma management of both treatment and control groups provided similar background therapy. The primary focus of the review is on daily vitamin C supplementation to prevent exacerbations and improve HRQL. The short-term use of vitamin C at the time of exacerbations or for cold symptoms in people with asthma are outside the scope of this review.. Two review authors independently screened the titles and abstracts of potential studies, and subsequently screened full text study reports for inclusion. We used standard methods expected by The Cochrane Collaboration.. A total of 11 trials with 419 participants met our inclusion criteria. In 10 studies the participants were adults and only one was in children. Reporting of study design was inadequate to determine risk of bias for most of the studies and poor availability of data for our key outcomes may indicate some selective outcome reporting. Four studies were parallel-group and the remainder were cross-over studies. Eight studies included people with asthma and three studies included 40 participants with exercise-induced asthma. Five studies reported results using single-dose regimes prior to bronchial challenges or exercise tests. There was marked heterogeneity in vitamin C dosage regimes used in the selected studies, compounding the difficulties in carrying out meaningful analyses.One study on 201 adults with asthma reported no significant difference in our primary outcome, health-related quality of life (HRQL), and overall the quality of this evidence was low. There were no data available to evaluate the effects of vitamin C supplementation on our other primary outcome, exacerbations in adults. One small study reported data on asthma exacerbations in children and there were no exacerbations in either the vitamin C or placebo groups (very low quality evidence). In another study conducted in 41 adults, exacerbations were not defined according to our criteria and the data were not available in a format suitable for evaluation by our methods. Lung function and symptoms data were contributed by single studies. We rated the quality of this evidence as moderate, but further research is required to assess any clinical implications that may be related to the changes in these parameters. In each of these outcomes there was no significant difference between vitamin C and placebo. No adverse events at all were reported; again this is very low quality evidence.Studies in exercise-induced bronchoconstriction suggested some improvement in lung function measures with vitamin C supplementation, but theses studies were few and very small, with limited data and we judged the quality of the evidence to be low.. Currently, evidence is not available to provide a robust assessment on the use of vitamin C in the management of asthma or exercise-induced bronchoconstriction. Further research is very likely to have an important impact on our confidence in the estimates of effect and is likely to change the estimates. There is no indication currently that vitamin C can be recommended as a therapeutic agent in asthma. There was some indication that vitamin C was helpful in exercise-induced breathlessness in terms of lung function and symptoms; however, as these findings were provided only by small studies they are inconclusive. Most published studies to date are too small and inconsistent to provide guidance. Well-designed trials with good quality clinical endpoints, such as exacerbation rates and health-related quality of life scores, are required.

Topics: Administration, Inhalation; Adult; Antioxidants; Ascorbic Acid; Asthma; Asthma, Exercise-Induced; Child; Health Status; Humans; Quality of Life; Randomized Controlled Trials as Topic

Topics: Antioxidants; Ascorbic Acid; Asthma; Dietary Supplements; Humans; Randomized Controlled Trials as Topic

Vitamin C is one of the key antioxidant vitamins which is abundant in the extracellular fluid lining the lung and low vitamin C intake has been associated with pulmonary dysfunction.. To evaluate the evidence for the efficacy of vitamin C in the treatment of asthma.. The Cochrane Airways Review Group asthma register was searched and bibliographies of studies identified were also checked for further trials. This review has been updated by searches to August 2008.. Only randomised controlled trials were eligible for inclusion. Studies were considered for inclusion if they dealt with the treatment of asthma using vitamin C supplementation. Two independent reviewers identified potentially relevant studies using pre-defined criteria and selected studies for inclusion.. Data were abstracted independently by two reviewers. Information on patients, methods, interventions, outcomes and results was extracted using standard forms.. Nine studies met the review entry criteria, randomising a total of 330 participants. Study design varied and the reporting was generally poor. Five trials contributed numerical data to the review. They provided outcome data on lung function, symptom scores, IgE levels and inhaled steroid use. One small study showed a significant difference in % drop in FEV1 post-exercise.. At present, evidence from randomised-controlled trials is insufficient to recommend a specific role for vitamin C in the treatment of asthma. Further methodologically strong and large-scale randomised controlled trials are needed in order to address the question of the effectiveness of vitamin C in children with asthma.

Topics: Antioxidants; Ascorbic Acid; Asthma; Dietary Supplements; Humans; Randomized Controlled Trials as Topic

Epidemiological studies suggest that dietary intake of vitamins A, C and E may be associated with the occurrence of asthma. A systematic review and meta-analysis was conducted in accordance with MOOSE guidelines to determine whether vitamins A, C and E, measured as dietary intakes or serum levels, are associated with asthma.. MEDLINE, EMBASE, CINAHL, CAB abstracts and AMED (up to November 2007), conference proceedings and bibliographies of papers were searched to identify studies of asthma, wheeze or airway responsiveness in relation to intakes and serum concentrations of vitamins A, C and E. Pooled odds ratios (OR) or mean differences (MD) with 95% confidence intervals (CI) were estimated using random effects models.. A total of 40 studies were included. Dietary vitamin A intake was significantly lower in people with asthma than in those without asthma (MD -82 microg/day, 95% CI -288 to -75; 3 studies) and in people with severe asthma than in those with mild asthma (MD -344 microg/day; 2 studies). Lower quantile dietary intakes (OR 1.12, 95% CI 1.04 to 1.21; 9 studies) and serum levels of vitamin C were also associated with an increased odds of asthma. Vitamin E intake was generally unrelated to asthma status but was significantly lower in severe asthma than in mild asthma (MD -1.20 microg/day, 95% CI -2.3 to -0.1; 2 studies).. Relatively low dietary intakes of vitamins A and C are associated with statistically significant increased odds of asthma and wheeze. Vitamin E intake does not appear to be related to asthma status.

Topics: Antioxidants; Ascorbic Acid; Asthma; Diet; Humans; Vitamin A; Vitamin E; Vitamins

It has been suggested that the rapid increase in asthma prevalence may in part be due to a decrease in the intake of dietary antioxidants, including vitamin C, vitamin E and beta-carotene. Epidemiological studies investigating the association between dietary antioxidant intake and asthma have generated inconsistent results. A meta-analysis was undertaken to examine the association between dietary antioxidant intake and the risk of asthma.. The MEDLINE database was searched for observational studies in English-language journals from 1966 to March 2007. Data were extracted using standardized forms. Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated using a random effects model. Ten studies were eligible for inclusion. Seven studies, comprising 13 653 subjects, used asthma or wheeze as their outcome; three studies explored the effect of antioxidant intake on lung function.. A higher dietary intake of antioxidants was not associated with a lower risk of having asthma. The pooled OR for having asthma were 1.06 (95% CI: 0.79-1.43) for subjects with a higher dietary vitamin C intake compared with those with a lower intake; 0.88 (95% CI: 0.61-1.25) for vitamin E; and 1.12 (95% CI: 0.77-1.62) for beta-carotene. There was no significant association between dietary antioxidant intake and lung function except for a positive association between vitamin C intake and an increase in FEV(1) (29.1 mL, 95% CI: -0.4-58.6, P = 0.05).. This meta-analysis does not support the hypothesis that dietary intake of the antioxidants vitamins C and E and beta-carotene influences the risk of asthma.

Topics: Antioxidants; Ascorbic Acid; Asthma; beta Carotene; Cross-Sectional Studies; Diet; Eating; Humans; Odds Ratio; Vitamin E

The influence of nutrition on chronic bronchial asthma has an important place in the management of this disease. Evidence suggests that specific inflammatory abnormalities exist in the airways of subjects suffering from mild-to-moderate persistent asthma, in whom an inflammatory state is often associated with increased generation of reactive oxygen species and the damaging effects of free radicals. For this reason oxidant stress may be an important pathogenic factor in the progress of the disease. The role of nutrition in bronchial asthma is related to antioxidant vitamins A, C, and E. By counteracting oxidants and reducing external attacks (bacteria, virus, toxins, xenobiotics) in the lung, antioxidant vitamins modulate the development of asthma and the impairment of pulmonary function. Dietary studies suggest relations between oxidative stress, bronchial inflammation, development of asthmatic symptoms, and reduction of cellular functions. Dietary interventions may reduce oxidant stress and prevent or minimize asthmatic symptoms. Such interventions may provide a cost-effective approach to asthma management that may supplement current pharmacological strategies, although this conclusion is not supported by many randomized, placebo-controlled studies. The aim of this short review is to summarize current knowledge regarding the relations between antioxidant vitamins and the treatment of bronchial asthma.

Topics: Antioxidants; Ascorbic Acid; Asthma; Dietary Supplements; Humans; Vitamin A; Vitamin E

Topics: Ascorbic Acid; Ascorbic Acid Deficiency; Asthma; Cardiovascular Diseases; Cataract; Common Cold; Humans; Nutrition Policy; Nutritional Requirements

For more than 50 years, the Food and Nutrition Board of the National Academy of Sciences has been reviewing nutrition research and defining nutrient requirements for healthy people, referred to as the Recommended Dietary Allowances (RDA). As new nutrition research is published, the importance of vitamins as vital nutrients is underscored, and new physiologic roles and applications to human health are examined and considered with regard to updating the RDA. Each year a substantial amount of new research is published on vitamins. This review examines recent research published on the importance of vitamin C with regard to general health.

Topics: Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Asthma; Cardiovascular Diseases; Diabetes Mellitus; Exercise; Humans; Hypersensitivity; Neoplasms

It has been hypothesized that decreasing antioxidant (fruit and vegetables), increased n-6 polyunsaturated fatty acid (PUFA; (margarine, vegetable oil), and decreased n-3 PUFA (oily fish) intakes have contributed to the recent increases in asthma and atopic disease. Epidemiologic studies in adults and children have reported beneficial associations between dietary antioxidants and lipids and parameters of asthma and atopic disease. The associations with n-6 and n-3 PUFA appear to be very complex and might differ between asthma and atopic dermatitis. Dietary antioxidants are probably exerting antioxidant and nonantioxidant immunomodulatory effects. Dietary lipids exert numerous complex effects on proinflammatory and immunologic pathways. It has also been suggested that atopic dermatitis is associated with an enzyme defect in lipid metabolism. In spite of this, the results of interventional supplementation studies in established disease have been disappointing, and there is now increasing interest in the possibility that dietary antioxidant and lipid intakes might be important in determining expression of disease during pregnancy and early childhood and that dietary interventions should be targeted at these groups. It also seems likely that there is individual variation in the responses of individuals to lipid, and probably antioxidant, supplementation. Further research to determine whether dietary intervention can reduce the risk of asthma and atopic disease is justified.

Topics: Animals; Antioxidants; Ascorbic Acid; Asthma; Child, Preschool; Clinical Trials as Topic; Diet; Dietary Fats; Dietary Supplements; Disease Models, Animal; Female; Fish Oils; Fruit; Humans; Hypersensitivity, Immediate; Lipid Metabolism; Lipids; Male; Pregnancy; Pregnancy Complications; Risk Factors; Selenium; Vegetables; Vitamin A; Vitamin E

Topics: Antioxidants; Ascorbic Acid; Asthma; Case-Control Studies; Copper; Cross-Sectional Studies; Diet; Diet Surveys; Environmental Exposure; Evidence-Based Medicine; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Flavonoids; Fruit; Humans; Longitudinal Studies; Magnesium; Risk Factors; Selenium; Sodium; Vegetables; Vitamin A; Vitamin E; Zinc

Vitamin C is one of the key antioxidant vitamins which is abundant in the extracellular fluid lining the lung and low vitamin C intake has been associated with pulmonary dysfunction.. To evaluate the evidence for the efficacy of vitamin C in the treatment of asthma.. The Cochrane Airways Review Group asthma register was searched and bibliographies of studies identified were also checked for further trials. This review has been updated by searches to January 2004.. Only randomised controlled trials were eligible for inclusion. Studies were considered for inclusion if they dealt with the treatment of asthma using vitamin C supplementation. Two independent reviewers identified potentially relevant studies using pre-defined criteria and selected studies for inclusion.. Data were abstracted independently by two reviewers. Information on patients, methods, interventions, outcomes and results was extracted using standard forms.. A total of 71 abstracts and titles were identified. Sixteen studies were selected for potential inclusion, eight met the inclusion criteria. All included studies were placebo-controlled and randomised. Only four provided data in a form that permitted further analysis and none could be aggregated in a meta analysis. The individual studies did not show a significant effect on any asthma outcome. The 2004 update for this review includes a large study in 201 adults on inhaled corticosteroids in which important benefit from the addition of vitamin C was excluded by the narrow confidence intervals of the lung function results.. At present, evidence from randomised-controlled trials is insufficient to recommend a specific role for vitamin C in the treatment of asthma. Further methodologically strong and large-scale randomised controlled trials are warranted in order to address the question of the effectiveness of vitamin C in children with asthma.

Topics: Antioxidants; Ascorbic Acid; Asthma; Dietary Supplements; Humans; Randomized Controlled Trials as Topic

Vitamin C is one of the key antioxidant vitamins which is abundant in the extracellular fluid lining the lung and low vitamin C intake has been associated with pulmonary dysfunction.. To evaluate the evidence for the effectiveness of vitamin C in the treatment of asthma.. The Cochrane Airways Review Group asthma register was searched and bibliographies of studies identified were also checked for further trials.. Only randomised controlled trials were eligible for inclusion. Studies were considered for inclusion if they dealt with the treatment of asthma using vitamin C supplementation. Two independent reviewers identified potentially relevant studies using pre-defined criteria and selected studies for inclusion.. Data were abstracted independently by two reviewers. Information on patients, methods, interventions, outcomes and results was extracted using standard forms.. A total of 65 abstracts and titles were identified. Ten studies were selected for potential inclusion, six met the inclusion criteria. All included studies were placebo-controlled and randomised. Only three provided data in a form that permitted further analysis and none could be aggregated in a meta analysis. The individual studies produced no significant effect on any asthma outcome.. At present, evidence from randomised-controlled trials is insufficient to recommend a specific role for vitamin C in the treatment of asthma. A methodologically strong and large-scale randomised controlled trial is warranted in order to address the question of the effectiveness of vitamin C in patients with asthma.

Topics: Ascorbic Acid; Asthma; Humans; Randomized Controlled Trials as Topic

Asthma is a syndrome that may have many causes resulting in airway inflammation and hyperresponsiveness. The search for the causes of asthma has led to the investigation of genetic, atopic, viral, and nutritional factors. For the last 2 decades, a number of studies have linked particular nutrients to asthma. The studies have examined both the suboptimal status of particular nutrients as causes of asthma and supplements of specific nutrients as therapy for asthma. We reviewed and analyzed data from these studies to determine the role of nutritional therapy in the management of asthma. The studies on food allergies reveal that IgE-mediated reactions to food are a minor cause of respiratory symptoms, affecting more children than adults. Currently, there are no available data to support the use of nutritional supplements in the treatment of chronic asthma.

Topics: Ascorbic Acid; Asthma; Fish Oils; Food Hypersensitivity; Humans; Magnesium; Nutritional Physiological Phenomena; Selenium; Sodium

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Allergens; Antioxidants; Ascorbic Acid; Asthma; Child; Clinical Trials as Topic; Diet; Fish Oils; Food Hypersensitivity; Humans; Middle Aged; Potassium; Pyridoxine; Selenium; Sodium; Trace Elements

To define what role vitamin C may or may not play in the treatment of asthma.. A comprehensive literature search of relevant English-language papers identified through a Medline search and from bibliographies of the identified papers.. We identified papers and studies pertaining to vitamin C in asthma and allergy and analyzed these studies according to their design, inclusion and exclusion criteria, population studied, variables or factors tested, method of intervention or treatment with vitamin C, and results and conclusions. We reviewed our data and divided it based on significant or insignificant roles of vitamin C in asthma and allergy.. From our review, we found a number of studies that support the use of vitamin C in asthma and allergy. Significant results include positive effects on pulmonary function tests, bronchoprovocation challenges with methacholine or histamine or allergens, improvement in white blood cell function and motility, and a decrease in respiratory infections. Our review also revealed several studies that did not support a beneficial role in vitamin C in asthma and allergy. These studies did not report improvements in pulmonary function tests or bronchoprovocation challenges. No benefit was noted in these studies when testing cutaneous reactivity or specific immunologic factors and levels.. Clearly from our review, the role of vitamin C in asthma and allergy is not well defined. The majority of the studies were short term and assessed immediate effects of vitamin C supplementation. Long term supplementation with vitamin C or delayed effects need to be studied. Although, the current literature does not support a definite indication for the use of vitamin C in asthma and allergy, the promising and positive studies revive curiosity and interest. With a large portion of health care dollars being spent on alternative medicine and vitamin C in particular, further studies are needed to define its role.

Topics: Ascorbic Acid; Asthma; Humans

Topics: Adrenal Glands; Animals; Ascorbic Acid; Asthma; Histamine; Humans; Lung; Prostaglandins

Vitamins are a group of organic compounds occurring naturally in food and are necessary for good health. Lack of a vitamin may lead to a specific deficiency syndrome, which may be primary (due to inadequate diet) or secondary (due to malabsorption or to increased metabolic need), and it is rational to use high-dose vitamin supplementation in situations where these clinical conditions exist. However, pharmacological doses of vitamins are claimed to be of value in a wide variety of conditions which have no, or only a superficial, resemblance to the classic vitamin deficiency syndromes. The enormous literature on which these claims are based consists mainly of uncontrolled clinical trials or anecdotal reports. Only a few studies have made use of the techniques of randomisation and double-blinding. Evidence from such studies reveals a beneficial therapeutic effect of vitamin E in intermittent claudication and fibrocystic breast disease and of vitamin C in pressure sores, but the use of vitamin A in acne vulgaris, vitamin E in angina pectoris, hyperlipidaemia and enhancement of athletic capacity, of vitamin C in advanced cancer, and niacin in schizophrenia has been rejected. Evidence is conflicting or inconclusive as to the use of vitamin C in the common cold, asthma and enhancement of athletic capacity, of pantothenic acid in osteoarthritis, and folic acid (folacin) in neural tube defects. Most of the vitamins have been reported to cause adverse effects when ingested in excessive doses. It is therefore worthwhile to consider the risk-benefit ratio before embarking upon the use of high-dose vitamin supplementation for disorders were proof of efficacy is lacking.

Topics: Acne Vulgaris; Ascorbic Acid; Asthma; Cardiovascular Diseases; Common Cold; Fibrocystic Breast Disease; Humans; Neoplasms; Osteoporosis; Vitamin A; Vitamin B Complex; Vitamin D; Vitamin E; Vitamin K; Vitamins

We previously reported that asthmatic children with GSTM1 null genotype may be more susceptible to the acute effect of ozone on the small airways and might benefit from antioxidant supplementation. This study aims to assess the acute effect of ozone on lung function (FEF(25-75)) in asthmatic children according to dietary intake of vitamin C and the number of putative risk alleles in three antioxidant genes: GSTM1, GSTP1 (rs1695), and NQO1 (rs1800566).. 257 asthmatic children from two cohort studies conducted in Mexico City were included. Stratified linear mixed models with random intercepts and random slopes on ozone were used. Potential confounding by ethnicity was assessed. Analyses were conducted under single gene and genotype score approaches.. The change in FEF(25-75) per interquartile range (60 ppb) of ozone in persistent asthmatic children with low vitamin C intake and GSTM1 null was -91.2 ml/s (p = 0.06). Persistent asthmatic children with 4 to 6 risk alleles and low vitamin C intake showed an average decrement in FEF(25-75) of 97.2 ml/s per 60 ppb of ozone (p = 0.03). In contrast in children with 1 to 3 risk alleles, acute effects of ozone on FEF25-75 did not differ by vitamin C intake.. Our results provide further evidence that asthmatic children predicted to have compromised antioxidant defense by virtue of genetic susceptibility combined with deficient antioxidant intake may be at increased risk of adverse effects of ozone on pulmonary function.

Topics: Age Factors; Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Asthma; Child; Cohort Studies; Dietary Supplements; Double-Blind Method; Environmental Exposure; Enzymes; Female; Gene-Environment Interaction; Genetic Predisposition to Disease; Glutathione S-Transferase pi; Glutathione Transferase; Humans; Linear Models; Lung; Male; Maximal Midexpiratory Flow Rate; Mexico; NAD(P)H Dehydrogenase (Quinone); Ozone; Phenotype; Polymorphism, Genetic; Risk Assessment; Risk Factors; Urban Health

Oxidative stress mediated by reactive oxygen species is known to contribute to the inflammatory process of bronchial asthma. Reactive oxygen species are released into the bronchial tree by activated inflammatory cells. In this study, we aimed to determine the effect of vitamin C administration on leukocyte vitamin C level as well as severity of asthma. In this double blind clinical trial study we evaluated 60 patients with chronic stable asthma. The patients were divided into two groups (A and B) including 30 patients in each group. Patients in these groups were matched according to their age, weight, height, gender, BMI and drug consumption. In addition to standard asthma treatment (according to stepwise therapy in 4th step of bronchial asthma) in which the patients were controlled appropriately, group A received 1000 mg vitamin C daily and group B received placebo. At the baseline and after one month treatment, non-fasting blood samples were drawn for laboratory evaluations. Asthmatic patient's clinical condition was evaluated through standard pulmonary function test (PFT). The mean (±SD) leukocyte vitamin C level in group A at the baseline and after one month treatment with 1000 mg/day vitamin C, were 0.0903 (±0.0787) µg/108 leukocytes and 0.1400 (±0.0953) µg/108 leukocytes respectively (P<0.05). The mean (±SD) leukocyte vitamin C level in group B at the baseline and after one month administration of placebo, were 0.0867 (±0.0629) µg/108 leukocytes and 0.0805(±0.0736) µg/108 leukocytes respectively. The leukocyte vitamin C level in group A was higher than those of group B after one month treatment with vitamin C and placebo and the difference was statistically significant (P<0.05). Comparing PFT (FEV1, FVC and FEV1/FVC) in group B during the study period showed a significant increase in FEV1 (P<0.05), while the other two parameters remained unchanged. In group A, who received 1000 mg/day vitamin C, none of the spirometry parameters changed after one month treatment, indicating no effect of vitamin C treatment in the spirometry parameters.

Topics: Adult; Antioxidants; Ascorbic Acid; Asthma; Chronic Disease; Double-Blind Method; Female; Forced Expiratory Volume; Humans; Iran; Leukocytes; Lung; Male; Middle Aged; Severity of Illness Index; Time Factors; Treatment Outcome; Vital Capacity

Oxidative stress plays a significant role in allergic airway inflammation. Supplementation with alpha-tocopherol (alone or combined with ascorbate/vitamin C) has been assessed as an intervention for allergic airway diseases with conflicting results. Enhancing levels of airway antioxidants with oral supplements has been suggested as an intervention to protect individuals from the effect of inhaled oxidants, although it is unclear whether supplementation changes tocopherol or vitamin C levels in both serum and airway fluids. Our objective was to obtain pilot safety and dosing data from 14 allergic asthmatic volunteers examining the effect of daily combination oral therapy with 500 mg alpha-tocopherol (alpha T) and 2 g vitamin C for 12 wk. We examined serum and airway fluid and cellular levels of alpha- and gamma-tocopherol (gamma T) and vitamin C to plan for future studies of these agents in asthma and allergic rhinitis. Six volunteers completed 12 wk of active treatment with alpha T and vitamin C and 8 completed placebo. Blood and sputum samples were obtained at baseline and at 6 wk and 12 wk of therapy and were analyzed for alpha T, gamma T, and vitamin C levels in the serum, sputum supernatant, and sputum cells. Combination treatment increased serum vitamin C and significantly decreased sputum alpha T and serum gamma T levels. No changes were found in sputum supernatant or sputum cell vitamin C or serum alpha T levels in the active treatment group. In conclusion, supplementation with alpha T and high-dose vitamin C does not augment vitamin C levels in the respiratory-tract lining fluid.

Topics: Administration, Oral; Adult; alpha-Tocopherol; Ascorbic Acid; Asthma; Capsules; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Drug Therapy, Combination; Female; Forced Expiratory Volume; gamma-Tocopherol; Humans; Male; Respiratory Mucosa; Serum; Sputum; Vitamins

Bronchial asthma is a chronic inflammatory airways disease. Nutritional intervention is an important tool to decrease the severity of many chronic inflammatory diseases including asthma. The aim of this study is to evaluate the role of omega-3 fatty acids, vitamin C and Zn in children with moderately persistent asthma.. Randomly assigned, placebo-self-controlled 60 children with moderate persistent asthma completed the study, were subjected to alternating phases of supplementation with omega-3 fatty acids, vitamin C and Zn either singly or in combination separated with washout phases. Childhood asthma control test (C-ACT), pulmonary function tests and sputum inflammatory markers were evaluated at the beginning of the study and at the end of each therapeutic phase.. There was a significant improvement of C-ACT, pulmonary function tests and sputum inflammatory markers with diet supplementation with omega-3 fatty acids, vitamin C and Zn (p < 0.001*). There was also significant improvement with the combined use of the three supplementations than single use of any one of them (p < 0.001*).. Diet supplementation with omega-3 fatty acids, Zn and vitamin C significantly improved asthma control test, pulmonary function tests and pulmonary inflammatory markers in children with moderately persistent bronchial asthma either singly or in combination.

Topics: Ascorbic Acid; Asthma; Biomarkers; Child; Cross-Over Studies; Dietary Supplements; Fatty Acids, Omega-3; Female; Humans; Inflammation Mediators; Male; Respiration; Respiratory Function Tests; Sputum; Zinc

Previous research has shown that diet can modify the bronchoconstrictor response to exercise in asthmatic subjects.. Determine the effect of ascorbic acid supplementation on pulmonary function and several urinary markers of airway inflammation in asthmatic subjects with exercise-induced bronchoconstriction (EIB).. Eight asthmatic subjects with documented EIB participated in a randomized, placebo controlled double-blind crossover trial. Subjects entered the study on their usual diet and were placed on either 2 weeks of ascorbic acid supplementation (1500 mg/day) or placebo, followed by a 1-week washout period, before crossing over to the alternative diet. Pre- and post-exercise pulmonary function, asthma symptom scores, fraction of exhaled nitric oxide (FENO), and urinary leukotriene (LT) C4-E4 and 9alpha, 11beta-prostagladin (PG) F2] were assessed at the beginning of the trial (usual diet) and at the end of each treatment period.. The ascorbic acid diet significantly reduced (p < 0.05) the maximum fall in post-exercise FEV1 (-6.4 +/- 2.4%) compared to usual (-14.3 +/- 1.6%) and placebo diet (-12.9 +/- 2.4%). Asthma symptoms scores significantly improved (p<0.05) on the ascorbic acid diet compared to the placebo and usual diet. Post-exercise FENO, LTC4-E4 and 9alpha, 11beta-PGF2 concentration was significantly lower (p<0.05) on the ascorbic acid diet compared to the placebo and usual diet.. Ascorbic acid supplementation provides a protective effect against exercise-induced airway narrowing in asthmatic subjects.

Topics: Adult; Anti-Asthmatic Agents; Ascorbic Acid; Asthma; Asthma, Exercise-Induced; Bronchoconstriction; Cross-Over Studies; Dietary Supplements; Double-Blind Method; Exercise Test; Female; Humans; Male; Respiratory Function Tests

The study aims to assess the a priori hypothesis that regular supplementation with vitamin C or magnesium will permit a reduction in the corticosteroid dose required to maintain asthma control in adults.. We invited all participants recruited from primary care centres who completed a parallel-group, randomised, placebo-controlled, 16-week supplementation trial of 1g/day vitamin C or 450 mg/day magnesium to continue and participate in a structured corticosteroid reduction protocol over 10 weeks.. A total of 92 participants (29 vitamin C, 31 magnesium and 32 placebo) entered the study. Assuming no reduction in corticosteroid dose in the 10 who subsequently withdrew, the geometric mean reductions in inhaled corticosteroid dose achieved with vitamin C, magnesium and placebo were 49, 13 and 11 microg, respectively. Relative to placebo, the unadjusted effect of vitamin C was significant, and remained at borderline significance after adjustment for baseline corticosteroid dose (relative reduction ratio=4.03, 95% CI 0.95 to 17.1, P=0.06).. We conclude that while vitamin C supplements may have modest corticosteroid sparing effects and hence the potential to reduce exposure to their side effects, magnesium supplements have no effect on the inhaled corticosteroid dose required to maintain asthma control.

Topics: Administration, Inhalation; Adolescent; Adult; Ascorbic Acid; Asthma; Beclomethasone; Double-Blind Method; England; Female; Glucocorticoids; Humans; Magnesium; Male; Middle Aged; Vitamins

Bronchial asthma is a chronic inflammatory disease of respiratory system, with disturbances in the dynamic balance of oxidant-antioxidant capacity of the lungs. Long-term administration of corticosteroids has been shown to result in mitochondrial dysfunction and oxidative damage of mitochondrial and nuclear DNAs. We previously documented decreased coenzyme Q(10) (CoQ(10)) and alpha-tocopherol concentrations in plasma and blood in corticosteroid-dependent bronchial asthma patients. In the present study we demonstrate that CoQ(10) supplementation reduces the dosage of corticosteroids in these patients.. This was an open, cross-over, randomized clinical study with 41 bronchial asthma patients (13 males, 28 females), ages 25-50 years. All patients suffered from persistent mild to moderate asthma. The patients were divided into two groups, one group receiving standard antiasthmatic therapy and clinically stabilized, and the second group receiving, in addition, antioxidants consisting of CoQ(10) as Q-Gel (120 mg) + 400 mg alpha-tocopherol + 250 mg vitamin C a day. The groups were crossed over at 16 weeks for a total duration of 32 weeks.. Data show that patients with corticosteroid-dependent bronchial asthma have low plasma CoQ(10) concentrations that may contribute to their antioxidant imbalance and oxidative stress. A reduction in the dosage of corticosteroids required by the patients following antioxidant supplementation was observed, indicating lower incidence of potential adverse effects of the drugs, decreased oxidative stress. This study also demonstrates the significant uptake of CoQ(10) by lung tissue in a rat model using hydrosoluble CoQ(10) (Q-Gel).

Topics: Adrenal Cortex Hormones; Adult; alpha-Tocopherol; Animals; Ascorbic Acid; Asthma; Coenzymes; Cross-Over Studies; Female; Humans; Lung; Male; Middle Aged; Mitochondria; Rats; Rats, Wistar; Ubiquinone

The inflammatory response to ozone in atopic asthma suggests that soluble mediators of inflammation are released in response to oxidant stress. Antioxidants may alleviate additional oxidative stress associated with photochemical oxidant pollution. This study investigates the impact of antioxidant supplementation on the nasal inflammatory response to ozone exposure in atopic asthmatic children. We conducted a randomized trial using a double-blinded design. Children with asthma (n = 117), residents of Mexico City, were given randomly a daily supplement of vitamins (50 mg/day of vitamin E and 250 mg/day of vitamin C) or placebo. Nasal lavages were performed three times during the 4-month follow-up and analysed for content of interleukin-6 (IL-6), IL-8, uric acid and glutathione (GSx). IL-6 levels in the nasal lavage were increased significantly in the placebo group after ozone exposure while no increase was observed in the supplement group. The difference in response to ozone exposure between the two groups was significant (P = 0.02). Results were similar for IL-8, but with no significant difference between the groups (P = 0.12). GSx decreased significantly in both groups. Uric acid decreased slightly in the placebo group. Our data suggest that vitamin C and E supplementation above the minimum dietary requirement in asthmatic children with a low intake of vitamin E might provide some protection against the nasal acute inflammatory response to ozone.

Topics: Air Pollutants; alpha-Tocopherol; Antioxidants; Ascorbic Acid; Asthma; Child; Dietary Supplements; Double-Blind Method; Environmental Exposure; Female; Glutathione; Humans; Interleukin-6; Interleukin-8; Male; Nasal Cavity; Oxidative Stress; Ozone; Uric Acid; Vitamin E

Epidemiological studies suggest that higher intakes of dietary vitamin C and magnesium may be associated with a reduced risk of asthma.. To determine whether vitamin C or magnesium supplements improve the clinical control of asthma in primary care patients.. A randomized, placebo-controlled, double-blind parallel group trial of 16 weeks supplementation with 1 g/day vitamin C, 450 mg/day magnesium chelate or matched placebo. Three hundred patients aged 18-60 years with physician-diagnosed asthma, controlled with at least one dose of an inhaled corticosteroid daily, were recruited from 24 primary care practices in Nottingham, UK. The main outcome measures were change in forced expiratory volume in 1 s, forced vital capacity, airway responsiveness to methacholine, mean morning and evening peak flow, symptom scores and bronchodilator use, both individually and as a combined summary statistic.. There was no evidence of any beneficial effect of either supplement on any outcome measure of asthma control in the primary intention-to-treat analysis, or in an analysis restricted to participants who completed the study.. Regular dietary supplementation with vitamin C or magnesium adds no clinical benefit to current standard therapy of asthma in primary care patients.

Topics: Adolescent; Adult; Ascorbic Acid; Asthma; Double-Blind Method; Female; Humans; Magnesium; Male; Middle Aged; Primary Health Care; Respiratory Mechanics; Treatment Outcome; Treatment Refusal

To explore the effects in normal and asthmatic adults of exposure to 200 ppb sulphur dioxide (SO2) and 200 microg/m3 and 2000 microg/m3 aerosols of ammonium bisulphate (AB) and sulphuric acid (SA) (MMD 0.3 microm).. Exposures were placebo controlled, for one hour at rest, double blind in random order. DeltaFEV1 was the primary outcome; secondary outcomes included symptoms, ventilation, exhaled nitric oxide (NO) concentrations, and nasal lavage fluid ascorbic (AA) and uric acid (UA) concentrations.. There were no significant changes in spirometry or symptoms with any exposure in either group. SO2 exposure was associated with an increased respiratory rate relative to air exposure in the asthmatic group (SO2: 958.9 breaths/hour; air: 906.8 breaths/hour) but the mean volume breathed did not differ significantly (SO2: 318.8 litres; air: 311.4 litres). AB exposures were associated with a significant rise in [NO] in the asthmatic (+1.51 ppb, and +1.39 ppb), but not in the normal group. Mean pre- and post-exposure [AA] tended to be higher in the normal than in the asthmatic group. Within each group, [AA] did not change significantly with any exposure. Post-exposure [UA] were greater than pre-exposure concentrations for all exposures, significantly so in the normal group for all exposures except SO2. There were no significant differences in the mean change in [UA] for any exposure relative to air.. The pollutant exposure concentrations employed in this study were generally much greater than ambient. It is unlikely that short lived exposures at lower concentrations would show significant effects, but effects of longer term lower concentration exposures cannot be ruled out.

Topics: Adult; Air Pollutants; Ammonium Sulfate; Antioxidants; Ascorbic Acid; Asthma; Double-Blind Method; Female; Forced Expiratory Volume; Humans; Male; Nasal Mucosa; Nitric Oxide; Sulfur Dioxide; Sulfuric Acids; Uric Acid

To evaluate whether acute effects of ozone, nitrogen dioxide, and particulates with mass median diameter less than 10 micro m could be attenuated by antioxidant vitamin supplementation, we conducted a randomized trial using a double-blinded design. Children with asthma (n = 158) who were residents of Mexico City were randomly given a daily supplement of vitamins (50 mg/day of vitamin E and 250 mg/day of vitamin C) or a placebo and were followed from October 1998 to April 2000. Pulmonary function tests were carried out twice a week in the morning. During the follow-up observation period, the mean 1-hour maximum ozone level was 102 ppb (SD = 47), and the mean 24-hour average PM(10) level was 56.7 micro g/m(3) (SD = 27.4). In children with moderate and severe asthma, ozone levels 1 day before spirometry were inversely associated significantly with forced expiratory flow (FEF(25-75)) (-13.32 ml/second/10 ppb; p = 0.000), FEV(1) (-4.59 ml/10 ppb; p = 0.036), and peak expiratory flow (PEF) (-15.01 ml/second/10 ppb; p = 0.04) in the placebo group after adjusting for potential confounding factors. No association between ozone and lung functions was observed in the supplement group. We observed significant differences in lung function decrements between groups for FEF(25-75) and PEF. Our results suggest that supplementation with antioxidants might modulate the impact of ozone exposure on the small airways of children with moderate to severe asthma.

Topics: Air Pollutants; Antioxidants; Ascorbic Acid; Asthma; Child; Dietary Supplements; Double-Blind Method; Female; Follow-Up Studies; Humans; Male; Nitrogen Dioxide; Ozone; Reference Values; Respiratory Function Tests; Severity of Illness Index; Treatment Outcome; Vitamin E

The air pollutant ozone induces both airway inflammation and restrictions in lung function. These responses have been proposed to arise as a consequence of the oxidizing nature of ozone, depleting endogenous antioxidant defenses with ensuing tissue injury. In this study we examined the impact of an environmentally relevant ozone challenge on the antioxidant defenses present at the surface of the lung in two groups known to have profound differences in their antioxidant defense network: healthy control (HC) and mild asthmatic (MA) subjects. We hypothesized that baseline differences in antioxidant concentrations within the respiratory tract lining fluid (RTLF), as well as induced responses, would predict the magnitude of individual responsiveness. We observed a significant loss of ascorbate (ASC) from proximal (-45.1%, p <.01) and distal RTLFs (-11.7%, p <.05) in healthy subjects 6 h after the end of the ozone challenge. This was associated (Rs, -0.71, p <.01) with increased glutathione disulphide (GSSG) in these compartments (p =.01 and p <.05). Corresponding responses were not seen in asthmatics, where basal ASC concentrations were significantly lower (p <.01) and associated with elevated concentrations of GSSG (p <.05). In neither group was any evidence of lipid oxidation seen following ozone. Despite differences in antioxidant levels and response, the magnitude of ozone-induced neutrophilia (+20.6%, p <.01 [HC] vs. +15.2%, p =.01 [MA]) and decrements in FEV(1) (-8.0%, p <.01 [HC] vs. -3.2%, p <.05 [MA]) did not differ between the two groups. These data demonstrate significant differences between the interaction of ozone with RTLF antioxidants in MA and HC subjects. These responses and variations in basal antioxidant defense were not, however, useful predictive markers of group or individual responsiveness to ozone.

Topics: Adult; Antioxidants; Ascorbic Acid; Asthma; Bronchial Provocation Tests; Bronchoscopy; Double-Blind Method; Female; Glutathione Disulfide; Humans; Lung; Male; Middle Aged; Neutrophils; Ozone; Predictive Value of Tests; Respiratory Function Tests; Respiratory System

We investigated the effect of theophylline administration on circulating vitamin levels in children with asthma. Twenty-three asthmatic children, ranging in age from 7 to 15 with a mean of 10.8 years and including 16 patients who were treated with slow-release theophylline and 7 patients not receiving any type of theophylline preparation, were enrolled in this study. They all were inpatients who had been hospitalized for the control of asthma. Steady-state serum theophylline and vitamin A, B1, B2, B6, B12 and C levels were evaluated in these patients. Circulating vitamin B1 and B6 levels were depressed in asthmatic children treated with theophylline compared to those not receiving the agent (38.4 +/- 1.6 (mean +/- SEM) vs. 46.4 +/- 3.5 ng/ml and 7.1 +/- 0.5 vs. 11.8 +/- 2.1 ng/ml, respectively, p < 0.05). A significant negative correlation between theophylline and circulating levels of vitamin B6 was demonstrated in the subjects of this study (rs = -0.657, p < 0.001). In contrast, no relationship was noted between theophylline and circulating vitamin B1 levels. Theophylline did not affect circulating vitamin A, B2, B12 or C levels. We conclude that theophylline induces depression of circulating vitamin B1 and B6 levels in asthmatic children, although a dose-dependent interaction between theophylline and vitamin B1 would be unlikely.

Topics: Adolescent; Ascorbic Acid; Asthma; Bronchodilator Agents; Child; Female; Humans; Male; Theophylline; Vitamin A; Vitamin B Complex; Vitamins

Sixteen adult subjects with asthma in a clinical steady state were studied. On day 1, after baseline spirometry, they underwent four histamine inhalation tests with functional recovery between each test. The provocative concentration causing a 20% fall in FEV1 (PC20) was obtained after each test. On days 2, 3, and 4, after baseline spirometry, active and placebo ascorbic acid (2 gm) was administered orally, double-blind, according to a 4.3.1 two-treatment crossover study design. One hour later, spirometry was performed, and PC20 was reassessed. We found no significant changes in FEV1 and FVC after ascorbic acid as compared with placebo administration. There was no difference between PC20 on days 2, 3, and 4 and by standardizing for the four PC20 results obtained on day 1. We conclude that ascorbic acid has no acute bronchodilator effect and does not alter bronchial responsiveness to histamine in subjects with asthma.

Topics: Adult; Airway Resistance; Ascorbic Acid; Asthma; Double-Blind Method; Female; Forced Expiratory Volume; Histamine; Humans; Lung Volume Measurements; Male; Middle Aged; Random Allocation; Respiratory Function Tests

Sixteen White children with bronchial asthma were divided into two groups; one received standard anti-asthma chemoprophylaxis (SAC) and the other SAC supplemented with 1 g ascorbic acid (Redoxon) given as a single daily dose for a 6-month period. In 10 patients the effects of ascorbic acid on exercise-induced bronchoconstriction (EIB) were assessed by comparing the pre-ascorbic acid results with those obtained 2 1/2 hours after the intravenous injection of 1 g ascorbic acid. Immunological investigations performed on the two groups were assessment of polymorphonuclear leucocyte (PMNL) motility, phagocytosis and nitroblue tetrazolium reduction and measurement of secretory IgA, serum immunoglobulin and total haemolytic complement levels and levels of the components C3 and C4, alpha 1-antitrypsin, antistreptolysin O (ASO), C-reactive protein and antibodies to certain respiratory viruses. These investigations were performed before and 1, 3 and 6 months after the commencement of therapy. Radio-allergosorbent testing for sensitivity to four common allergens was carried out at the outset and after 6 months of therapy. Injection of ascorbic acid had no detectable effects on the degree of EIB. Slight but not significant immunological changes were observed in the SAC group over the 6-month study period. However, in the SAC plus ascorbic acid group significantly improved PMNL motility and decreased ASO levels and reduced (although not to a significant extent) IgE levels and titres of antibodies to the respiratory viruses were observed.

Topics: Adolescent; Ascorbic Acid; Asthma; Child; Clinical Trials as Topic; Drug Therapy, Combination; Female; Humans; Immunoglobulins; Male; Neutrophils; Respiratory Function Tests

In order to study the potential benefit of ascorbic acid in asthma we investigated its role in exercise-induced bronchospasm (EIB). Twelve asthmatic subjects were recruited on the basis of findings compatible with EIB. On two subsequent days the subjects ingested 500 mg. of ascorbic acid or a placebo. The study was performed in a double-blind randomized fashion. Partial and maximal expiratory flow volume (PEFV and MEFV) curves were used to determine pulmonary function changes. Pretreatment with ascorbic acid led to a significant attenuation of the bronchospasm seen five minutes after exercise compared to placebo, as measured by FVC (0.23 +/- 0.08 L decrease after ascorbic acid, 0.48 +/- 0.14 L decrease after placebo) and by FEV1 (0.24 +/- 0.06 decrease after ascorbic acid, 0.44 +/- 0.14 decrease after placebo) Mean +/- SE). These results suggest a mild antibronchospastic action of ascorbic acid in subjects with EIB.

Topics: Adult; Ascorbic Acid; Asthma; Asthma, Exercise-Induced; Female; Forced Expiratory Volume; Humans; Male; Maximal Expiratory Flow-Volume Curves; Placebos; Vital Capacity

Forty-one asthmatic patients in remission were randomly allocated to two treatment groups in a double-blind trial. One group took 1 g, of ascorbic acid as one effervescent tablet once daily and the second group took a matching placebo. The asthmatics were selected from those attending the Asthma Clinic. One criterion for selection was the increase in exacerbation during the rainy season. These exacerbations were precipitated by respiratory infection. After 14 weeks, an assessment of the severity and rate of attacks showed that those on ascorbic acid suffered less severe and less frequent attacks of asthma during the study period. Plasma ascorbic acid astimations showed a significant rise in the level in those taking ascorbic acid over those on placebo. (P < 0.01). Cessation of ascorbic acid in the group taking it increased attack rates. It is concluded that high dose ascorbic acid is probably a good prophylaxis in some bronchial asthmatics.

Topics: Adolescent; Adult; Ascorbic Acid; Asthma; Drug Evaluation; Female; Humans; Male; Nigeria

Topics: Animals; Ascorbic Acid; Asthma; Cell Differentiation; Cell Proliferation; Cells, Cultured; Cyclic AMP Response Element-Binding Protein; Disease Models, Animal; Embryonic Stem Cells; Gene Expression Regulation; Humans; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Stem Cell Niche

Airway inflammation and oxidative stress are the two major characteristics of asthma pathogenesis. Therefore, this study evaluated the protective effects of ascorbic acid in combination with calcitriol on the oxidative damages and inflammation in asthma model. All animals, except in the control group, were sensitized and challenged with ovalbumin. One day after the last challenge, samples of bronchoalveolar lavage fluid was collected for the assessment of total white blood cell counts and differential count of white blood cell and plasma was used for the measurement of pro-oxidant/antioxidant balance level. Lung tissue samples were also stored for examining peribronchial inflammatory cell infiltration, phosphorylated nuclear factor-kappa B expression and measurement of malondialdehyde level. Induction of asthma caused significant increases in total white blood cell counts, percentage of neutrophils and eosinophils and a decrease in the percentage of lymphocytes. Moreover, asthma resulted in significant increases of peribronchial inflammatory cell infiltration, phosphorylated nuclear factor-kappa B expression and malondialdehyde level. However, no significant changes were observed in pro-oxidant/antioxidant balance level with the induction of asthma. Co-administration of low doses of ascorbic acid and calcitriol returned all to the levels measured before sensitization and challenge. Combination of low doses of ascorbic acid with calcitriol improves mouse asthma model by a possible additive effects through the decrease of oxidative stress and inflammation.

Topics: Animals; Anti-Inflammatory Agents; Ascorbic Acid; Asthma; Bronchoalveolar Lavage Fluid; Calcitriol; Calcium Channel Agonists; Chronic Disease; Drug Therapy, Combination; Leukocyte Count; Lung; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Oxidative Stress; Vitamins

To determine the implications of supplemental vitamin C for pregnant tobacco smokers and its effects on the prevalence of pediatric asthma, asthma-related mortality, and associated costs.. A decision-analytic model built via TreeAge compared the outcome of asthma in a theoretical annual cohort of 480,000 children born to pregnant smokers through 18 years of life. Vitamin C supplementation (500 mg/day) with a standard prenatal vitamin was compared to a prenatal vitamin (60 mg/day). Model inputs were derived from the literature. Deterministic and probabilistic sensitivity analyses assessed the impact of assumptions.. Additional vitamin C during pregnancy would prevent 1637 cases of asthma at the age of 18 per birth cohort of pregnant smokers. Vitamin C would reduce asthma-related childhood deaths and save $31,420,800 in societal costs over 18 years per birth cohort.. Vitamin C supplementation in pregnant smokers is a safe and inexpensive intervention that may reduce the economic burden of pediatric asthma.

Topics: Adolescent; Ascorbic Acid; Asthma; Child; Child, Preschool; Cost-Benefit Analysis; Decision Support Techniques; Dietary Supplements; Female; Humans; Infant; Infant Health; Infant, Newborn; Pregnancy; Prenatal Care; Primary Prevention; Quality-Adjusted Life Years; Respiratory Function Tests; Respiratory Sounds; Risk Assessment; Smoking; United States; Young Adult

Topics: Ascorbic Acid; Asthma; Child; Cost-Benefit Analysis; Dietary Supplements; Female; Humans; Infant, Newborn; Pregnancy; Smokers

Few studies to date have investigated the antioxidant nutrients such as vitamin C (ascorbic acid), vitamin E (α-tocopherol), retinol and carotenoids in plasma from patients with pulmonary disease in Japan. To clarify the role of antioxidant nutrients such as vitamin C, vitamin E, retinol and various carotenoids in plasma of Japanese patients with chronic obstructive lung diseases (COPD), asthma-COPD overlap syndrome (ACOS) and/or bronchial asthma (BA), we compared to healthy elderly controls.. Ascorbic acid (AA), carotenoids (lutein, zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene and lycopene), retinol and α-tocopherol levels in plasma were determined by using a high performance liquid chromatography. Reduced glutathione (GSH), oxidised glutathione (GSSG) in whole blood and urinary 8-OHdG were also determined.. Plasma AA level of COPD subjects was significantly lower than that of healthy elderly people. Conversely, ACOS and BA subjects showed no significant difference from healthy elderly people. Moreover, plasma lycopene and total carotenoid levels and GSH content in blood were significantly lower in COPD subjects than these in healthy elderly people. However, other redox markers such as GSSG, GSH/GSSG ratio and urinary 8-OHdG found no significant differences between COPD, ACOS and BA compared to healthy elderly people.. These results suggested that COPD of Japanese patients may develop partly because of oxidative stress derived from a shortage of antioxidant nutrients, especially of AA and lycopene, as well as GSH while this may not be the case in both ACOS and BA.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; Asthma; Biomarkers; Carotenoids; Chromatography, Liquid; Female; Food; Glutathione; Humans; Japan; Lycopene; Male; Middle Aged; Oxidative Stress; Pulmonary Disease, Chronic Obstructive; Respiratory Function Tests; Smoking

This study aims to determine the systemic oxidant-antioxidant status in Tunisian patients with asthma.. We evaluated the levels of malondialdehyde (MDA) as thiobarbituric acid complexes, total protein carbonyls (PCs) and advanced oxidation protein products (AOPP). The levels of total thiols, protein sulfhydryls, glutathione (GSH), together with hydrogen peroxide, ascorbic acid, iron and total antioxidant status (TAS) were colorimetrically estimated. Glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) activities were assessed in plasma and erythrocytes by spectrophotometry. We also determined the levels of nitric oxide (NO) and peroxynitrite in plasma from asthmatic patients and healthy controls. The volume of fractionated exhaled NO (FeNO) was evaluated by the Medisoft HypAir method. Estimation of DNA damage was determined using the comet assay.. Asthmatic patients showed increased levels of MDA in comparison to healthy controls (p < 0.001), while no significant difference was found in protein carbonyls (p = 0.79) and AOPP (p = 0.98). Patients with asthma also had significantly lower levels of total thiols (355.9 ± 15.72 versus 667.9 ± 22.65, p < 0.001), protein sulfhydryls (333.99 ± 16.41 versus 591.95 ± 24.28, p < 0.001) and glutathione (p < 0.001). They also showed decreased GSH-Px activity (p < 0.001), whereas no significant differences in measurements of catalase and SOD enzyme activities were observed between the two groups (respectively, p = 0.06 and p = 0.55). In addition, ascorbic acid and nitric oxide levels were decreased in asthmatics in comparison to controls (p < 0.01).. Our findings highlight that oxidative stress and defective anti-oxidative status are major alterations in Tunisian patients with asthma.

Topics: Adult; Advanced Oxidation Protein Products; Ascorbic Acid; Asthma; Biomarkers; Catalase; Female; Glutathione; Glutathione Peroxidase; Humans; Hydrogen Peroxide; Male; Malondialdehyde; Middle Aged; Nitric Oxide; Oxidative Stress; Protein Carbonylation; Respiratory Function Tests; Severity of Illness Index; Superoxide Dismutase; Tunisia

Asthma is characterized by airway inflammation, and bronchial airways are particularly susceptible to oxidant-induced tissue damage.. To investigate the effect of dietary antioxidant intake and environmental tobacco smoke (ETS) on the risk of childhood asthma according to genotypes susceptible to airway diseases.. This cross-sectional study included 1124 elementary school children aged 7-12 years old. Asthma symptoms and smoking history were measured using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Intake of vitamin A (including retinol and β-carotene), C, and E was measured by a semi-quantitative food frequency questionnaire (FFQ). GSTP1 polymorphisms were genotyped from peripheral blood samples.. ETS was significantly associated with presence of asthma symptoms (adjusted odds ratio [aOR], 2.48; 95 % confidence interval [CI], 1.29-4.76) and diagnosis (aOR, 1.91; 95 % CI, 1.19-3.06). Dietary antioxidant intake was not associated with asthma symptoms, although ETS plus low vitamin A intake showed a significant positive association with asthma diagnosis (aOR, 2.23; 95 % CI, 1.10-4.54). Children with AA at nucleotide 1695 in GSTP1 who had been exposed to ETS and a low vitamin A intake have an increased risk of asthma diagnosis (aOR, 4.44; 95 % CI,1.58-12.52) compared with children who had not been exposed to the two risk factors. However, ETS exposure and low vitamin A intake did not significantly increase odds of asthma diagnosis in children with AG or GG genotypes.. Low vitamin A intake and ETS exposure may increase oxidative stress and thereby risk for childhood asthma. These relationships may be modified by gene susceptibility alleles of GSTP1.

Topics: Ascorbic Acid; Asthma; beta Carotene; Child; Cross-Sectional Studies; Diet; Female; Gene-Environment Interaction; Genetic Predisposition to Disease; Glutathione S-Transferase pi; Humans; Male; Odds Ratio; Polymorphism, Genetic; Tobacco Smoke Pollution; Vitamin A; Vitamin E; Vitamins

Respiratory allergic disease is an inflammatory condition accompanied by oxidative stress. Supplementation of an anti-inflammatory agent with antioxidants may have a therapeutic effect. In this study, the effects of choline chloride in combination with antioxidants were evaluated via the intranasal route in a mouse model of allergic airway disease. Balb/c mice were sensitized on days 0, 7, and 14 and challenged on days 25-30 with cockroach extract (CE) and with a booster challenge on day 38. They were treated with choline chloride (ChCl; 1mg/kg), vitamin C (Vit C; 308.33 mg/kg), and selenium (Se; 1mg/kg) alone or in combination via the intranasal route on days 31, 33, 35, 37, and 39. The mice were sacrificed on day 40 to collect blood, bronchoalveolar lavage fluid, lungs, and spleen. Mice immunized with CE showed a significant increase in airway hyperresponsiveness (AHR), lung inflammation, Th2 cytokines, and the oxidative stress markers intracellular reactive oxygen species and 8-isoprostanes compared to the phosphate-buffered saline control group. A significant decrease was observed in these parameters with all the treatments (p<0.01). The highest decrease was noticed in the ChCl+Vit C+Se-treated group, with AHR decreased to the normal level. This group also showed the highest decrease in airway inflammation (p<0.001), IL-4 and IL-5 (p<0.001), IgE and IgG1 (p<0.001), NF-κB (p<0.001), and 8-isoprostane levels (p<0.001). Glutathione peroxidase activity, which was decreased significantly in CE-immunized mice, was restored to normal levels in this group (p<0.001). IL-10 level was decreased in CE-immunized mice and was restored to normal by combination treatment. The combination treatment induced FOXP3(+) cells in splenocyte culture, responsible for the upregulation of IL-10. In conclusion, the combination of choline chloride, vitamin C, and selenium via the intranasal route reduces AHR, inflammation, and oxidative stress, probably by causing IL-10 production by FOXP3(+) cells, and possesses therapeutic potential against allergic airway disease.

Topics: Administration, Intranasal; Animals; Anti-Inflammatory Agents; Antioxidants; Ascorbic Acid; Asthma; Bronchoalveolar Lavage Fluid; Choline; Cockroaches; Dinoprost; Drug Combinations; Eosinophil Peroxidase; Glutathione Peroxidase; Immunoglobulin E; Immunoglobulin G; Inflammation; Interleukin-10; Interleukin-4; Interleukin-5; Lipotropic Agents; Lung; Mice; Mice, Inbred BALB C; Oxidative Stress; Reactive Oxygen Species; Respiratory Hypersensitivity; Selenium; Spleen; Th2 Cells; Transcription Factor RelA

One hundred eighty-four asthmatic children were selected from 8 schools in Tainan City (high PM(10) [particulate matter with aerodynamic diameter <10 μm] exposure) and Hualien County (low PM(10) exposure) in Taiwan, and completed records of dietary consumption, daily peak expiratory flow rate (PEFR), and daily respiratory symptoms for 1 week. The higher prevalence of PEFR less than 80% predicted was found in children of high-exposure district than of low-exposure one, as well as in subjects with high intake of vitamin E than those who took less vitamin E. Furthermore, the risk of declining PEFR appeared to significantly decrease for subjects with both high intake of vitamins C and E and residing in area of low PM(10) levels as compared with those with low intake of vitamins C and E and residing in high-exposure area. The beneficiary effect of vitamin C and E intake on PEFR improvement for asthmatic children with low air pollution is suggested.

Topics: Air Pollutants; Ascorbic Acid; Asthma; Child; Diet; Environmental Exposure; Female; Humans; Inhalation Exposure; Male; Particle Size; Particulate Matter; Peak Expiratory Flow Rate; Surveys and Questionnaires; Taiwan; Vitamin E

Increasing childhood asthma rates may be due to changing dietary lifestyle. We investigated the association of dietary intake of antioxidant vitamins and fatty acids with asthma in Japanese pre-school children.. Cross-sectional study.. School-based survey on lifestyle/diet and health status in children in Japan.. Parents of 452 children aged 3-6 years completed a questionnaire on the children's and parents’ lifestyle and demographics. Children were classified into asthma cases and non-asthma cases in accordance with the ATS-DLD(American Thoracic Society and Division of Lung Diseases of the National Heart, Lung, and Blood Institute) questionnaire. Children's diet was assessed using a 3 d dietary record completed by parents. Children's age, sex, BMI, history of food allergy, maternal age, parental history of allergy, maternal education,family size and second-hand smoking were included as covariates. Logistic regression models were used to examine the association between children's diet and asthma.. Compared with children with the lowest intake tertile for vitamin C and vitamin E, those in the highest were significantly inversely associated with asthma; adjusted OR (95% CI) were 0?35 (0?14, 0?88) and 0?32 (0?12, 0?85),respectively. A statistically significant trend was also observed. Fruit intake showed an inverse but insignificant association with asthma. There were no associations of any type of fatty acids with asthma.. These data suggest that children with high intakes of vitamins C and E may be associated with a reduced prevalence of asthma.

Topics: Antioxidants; Ascorbic Acid; Asthma; Child; Child, Preschool; Cross-Sectional Studies; Diet; Fatty Acids; Feeding Behavior; Female; Fruit; Humans; Male; Vitamin E; Vitamins

Antioxidant intake may reduce the risk of allergic disease by protecting against oxidative tissue damage. Major sources of antioxidants in the Western world are fruits, vegetables (vitamin C, β-carotene, α-tocopherol), meat and milk (selenium, magnesium, zinc). Children may exclude or eat less of some fruits and vegetables due to cross-reactivity between pollen and these foods, complicating assessment of causal relationships.. To investigate the association between dietary antioxidant intake and allergic disease, taking potential reverse causation into account.. Data on 2442 8-year-old children from the Swedish birth cohort study BAMSE were analysed. Children with completed parental questionnaires on exposures and health, including a food-frequency questionnaire and who provided a blood sample were included. Associations between antioxidant intake during the past year and current allergic disease were analysed using logistic regression.. An inverse association was observed between intake of β-carotene and rhinitis (OR(adj), highest vs. lowest quartile, 0.67, 95% CI 0.49-0.93). Magnesium intake was inversely related to asthma (OR(adj), 0.65, 95% CI 0.42-1.00) and atopic sensitisation (OR(adj), 0.78, 95% CI 0.61-1.00). Following exclusion of children who avoided certain fruits, vegetables or milk due to allergic symptoms (n = 285), the inverse association remained between magnesium intake and asthma (OR(adj), 0.58, 95% CI 0.35-0.98), whereas all other associations became non-significant.. Diet modifications due to allergy may affect the antioxidant intake and needs to be considered when investigating the relationship between diet and allergic disease. Magnesium intake seems to have a protective effect on childhood asthma.

Topics: alpha-Tocopherol; Antioxidants; Ascorbic Acid; Asthma; beta Carotene; Child; Cohort Studies; Diet; Female; Humans; Hypersensitivity, Immediate; Magnesium; Male; Rhinitis, Allergic, Perennial; Surveys and Questionnaires; Sweden

In this study, combinations of Ginkgo biloba leaf extract (EGb761) plus the carotenoid antioxidant astaxanthin (ASX) and vitamin C were evaluated for a summative dose effect in the inhibition of asthma-associated inflammation in asthmatic guinea-pigs. Ovalbumin-sensitized Hartley guinea-pigs challenged with ovalbumin aerosol to induce asthma, were administered EGb761, ASX, vitamin C or ibuprofen. Following killing, bronchoalveolar lavage (BAL) fluid was evaluated for inflammatory cell infiltrates and lung tissue cyclic nucleotide content. Each parameter measured was significantly altered to a greater degree by drug combinations, than by each component acting independently. An optimal combination was identified that included astaxanthin (10 mg/kg), vitamin C (200 mg/kg) and EGb761 (10 mg/kg), resulting in counts of eosinophils and neutrophils each 1.6-fold lower; macrophages 1.8-fold lower, cAMP 1.4-fold higher; and cGMP 2.04-fold higher than levels in untreated, asthmatic animals (p < 0.05). In conclusion, EGb761, ASX and vitamin C are shown here to interact summatively to suppress inflammation with efficacy equal to or better than ibuprofen, a widely used non-steroidal antiinflammatory drug (NSAID). Such combinations of non-toxic phytochemicals constitute powerful tools for the prevention of onset of acute and chronic inflammatory disease if consumed regularly by healthy individuals; and may also augment the effectiveness of therapy for those with established illness.

Topics: Animals; Anti-Inflammatory Agents; Ascorbic Acid; Asthma; Drug Therapy, Combination; Ginkgo biloba; Guinea Pigs; Ibuprofen; Male; Plant Extracts; Xanthophylls

Dental erosion is a multifactorial disease and is associated with dietary habits in infancy and adolescence.. To investigate possible associations among dental erosion and diet, medical history and lifestyle habits in Brazilian schoolchildren.. The sample consisted of a random single centre cluster of 414 adolescents (12- and 16-years old) of both genders from private and public schools in Bauru (Brazil). The O'Brien [Children's Dental Health in the United Kingdom, 1993 (1994) HMSO, London] index was used for dental erosion assessment. Data on medical history, rate and frequency of food and drinks consumption, and lifestyle habits were collected by a self-reported questionnaire. Odds ratios with 95% confidence intervals were used to assess the univariate relationships between variables. Analysis of questionnaire items was performed by multiple logistic regression analysis. The statistical significance level was set at 5%.. The erosion present group comprised 83 subjects and the erosion absent group 331. There were no statistically significant correlations among dental erosion and the consumption of food and drinks, medical history, or lifestyle habits.. The results indicate that there was no correlation between dental erosion and the risk factors analysed among adolescents in Bauru/Brazil and further investigations are necessary to clarify the multifactorial etiology of this condition.

Topics: Adolescent; Ascorbic Acid; Asthma; Beverages; Brazil; Carbonated Beverages; Child; Cross-Sectional Studies; Diabetes Mellitus; Drinking Behavior; Drug Therapy; Feeding Behavior; Female; Food; Gastrointestinal Diseases; Humans; Life Style; Male; Risk Factors; Tooth Erosion; Vitamins; Vomiting

β(2)-agonists are the most effective bronchodilators for the rapid relief of asthma symptoms, but for unclear reasons, their effectiveness may be decreased during severe exacerbations. Because peroxidase activity and nitrogen oxides are increased in the asthmatic airway, we examined whether salbutamol, a clinically important β(2)-agonist, is subject to potentially inactivating nitration. When salbutamol was exposed to myeloperoxidase, eosinophil peroxidase or lactoperoxidase in the presence of hydrogen peroxide (H(2)O(2)) and nitrite (NO(2)(-)), both absorption spectroscopy and mass spectrometry indicated formation of a new metabolite with features expected for the nitrated drug. The new metabolites showed an absorption maximum at 410 nm and pK(a) of 6.6 of the phenolic hydroxyl group. In addition to nitrosalbutamol (m/z 285.14), a salbutamol-derived nitrophenol, formed by elimination of the formaldehyde group, was detected (m/z 255.13) by mass spectrometry. It is noteworthy that the latter metabolite was detected in exhaled breath condensates of asthma patients receiving salbutamol but not in unexposed control subjects, indicating the potential for β(2)-agonist nitration to occur in the inflamed airway in vivo. Salbutamol nitration was inhibited in vitro by ascorbate, thiocyanate, and the pharmacological agents methimazole and dapsone. The efficacy of inhibition depended on the nitrating system, with the lactoperoxidase/H(2)O(2)/NO(2)(-) being the most affected. Functionally, nitrated salbutamol showed decreased affinity for β(2)-adrenergic receptors and impaired cAMP synthesis in airway smooth muscle cells compared with the native drug. These results suggest that under inflammatory conditions associated with asthma, phenolic β(2)-agonists may be subject to peroxidase-catalyzed nitration that could potentially diminish their therapeutic efficacy.

Topics: Adrenergic beta-2 Receptor Agonists; Albuterol; Ascorbic Acid; Asthma; Breath Tests; Bronchi; Catalysis; Child; Cyclic AMP; Dapsone; Humans; Hydrogen Peroxide; Mass Spectrometry; Methimazole; Nitrites; Peroxidases; Receptors, Adrenergic, beta-2; Thiocyanates

Asthma is a chronic inflammatory airway disorder associated with recruitment of inflammatory cells. This study aims to clarify the role of oxidative stress and antioxidant status in the deterioration accompanied asthma.. Vitamin E, Vitamin C, superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH), total antioxidant status together with the concentrations of lipid peroxides, total nitrates and oxidative DNA damage (8-oxodeoxyguanine) were determined in plasma or whole blood of 47 Saudi asthmatic patients and compared to age-matching control samples.. The present study showed that asthmatic patients have significantly decreased levels of GSH, α-tocopherol, GPx, total antioxidant status and higher levels of SOD, lipid peroxides, total nitrate and 8-oxo-dG. Vitamin C recorded more or less similar levels in both groups.. Alteration of the selected measured parameters confirms that oxidative stress and defective antioxidant status could represent the primary causative factor in the pathogenesis of asthma.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adolescent; Adult; Aged; Aged, 80 and over; alpha-Tocopherol; Antioxidants; Ascorbic Acid; Asthma; Deoxyguanosine; DNA Damage; Female; Glutathione; Humans; Lipid Peroxidation; Lipid Peroxides; Male; Malondialdehyde; Middle Aged; Nitrates; Nitrites; Oxidative Stress; Saudi Arabia; Superoxide Dismutase; Young Adult

The rise of asthma prevalence in children observed the last years might be related to several dietary factors/components as suggested by several researchers. We aimed to evaluate the potential relationship between certain nutrients intake and asthma occurrence in a population of pre-school children. In the framework of the cross-sectional study 'Growth, Exercise and Nutrition Epidemiological Study In pre-schoolers', data were collected from 1964 children, aged 24-72 months, living in five different counties in Greece. The International Study of Asthma and Allergies in Childhood questionnaire was used to assess asthma related outcomes. Dietary intake was assessed with 3 days diet records. The prevalence of ever wheeze, current wheeze and diagnosed asthma was 37.7%, 27.5% and 10.5% respectively. Dietary intake of magnesium had a 0.5% and 0.6% increase in the reported risk of current wheeze and diagnosed asthma respectively. On the contrary a decrease in the prevalence of ever (OR: 0.997, 95% CI: 0.995-1.000) and current wheeze (OR: 0.996, 95% CI: 0.993-0.999) was associated with vitamin C intake. Calcium intake slightly decreased the risk of current wheeze (OR: 0.999, 95% CI: 0.998-0.999). An increase of 2% of the risk of reporting ever or current wheeze was associated with mono-unsaturated fatty acid intake. Magnesium intake was the only independent predictor for doctor's diagnosed asthma. We conclude that dietary intake of vitamin C and calcium seem to have a protective effect on the incidence of wheeze in pre-school children, whereas magnesium and mono-unsaturated fatty acid may have a harmful role.

Topics: Ascorbic Acid; Asthma; Body Mass Index; Calcium; Child; Child, Preschool; Cross-Sectional Studies; Diet; Energy Intake; Fatty Acids, Unsaturated; Female; Greece; Health Surveys; Humans; Magnesium; Male; Prevalence; Respiratory Sounds; Surveys and Questionnaires

To determine the oxidant - antioxidant imbalance in asthmatic children, by measuring the levels of malondialdehyde (MDA) as an oxidant marker of lipid peroxidation as well as antioxidant compounds like vitamin C, vitamin E and uric acid and to investigate whether their concentrations are associated with more severe asthma.. This case controlled prospective study was conducted on 219 children aged 1-12 years, attending Basra Maternity and Children Hospital. Included were 98 asthmatic children during acute attack and 121 nonasthmatic, apparently healthy children. Serum malondialdehyde (MDA) as an oxidant marker of lipid peroxidation, and vitamin C, vitamin E and uric acid (as antioxidants) were estimated in asthmatic children during acute attack and compared with non-asthmatic children.. Asthmatic children during exacerbation of their asthma have significant lower serum levels of antioxidant compounds like vitamin C, vitamin E and uric acid (p < 0.001) and significantly high malondialdehyde as compared with the controls. MDA was significantly elevated (P < 0.001), while that of vitamin C, vitamin E and uric acid were significantly decreased with increasing severity of asthmatic attack (P < 0.001). A significant negative correlation between MDA with vitamin C (P < 0.05, r = - 0.44) was observed in severe asthmatic attacks.. Asthmatic patients during acute attack suffer a high degree of reactive oxygen species formation causing considerable oxidative stress that is indicated by the high level of oxidants (MDA) and low level of antioxidants.

Topics: Acute Disease; Antioxidants; Ascorbic Acid; Asthma; Biomarkers; Case-Control Studies; Child; Child, Preschool; Female; Humans; Infant; Lipid Peroxidation; Male; Malondialdehyde; Oxidative Stress; Prospective Studies; Reactive Oxygen Species; Uric Acid; Vitamin E

Vitamin C is traditionally regarded to be beneficial for asthma, however the benefit is still controversial. In the present study, high dose vitamin C was supplemented to ovalbumin (OVA)-sensitized and challenged mice to evaluate the effects of dietary vitamin C on allergic asthma. In this study, the experimental mice were divided into four groups, including nonsensitized control, dietary control, positive control (cured ip with dexamethasone), and high dose vitamin C supplementation (130 mg of vitamin C/kg bw/day by gavage for 5 weeks). Differential leukocyte counts, levels of inflammatory mediators, as well as type 1 T-helper lymphocytes (Th1)-type and type 2 T-helper lymphocytes (Th2)-type cytokines in the bronchoalveolar lavage fluid (BALF) were determined. The results showed that both high dose vitamin C supplementation and dexamethasone treatments significantly (P < 0.05) decreased eosinophilic infiltration into BALF. High dose vitamin C supplementation significantly increased the secretion ratio of interferon (IFN)-gamma/interleukin (IL)-5 cytokines. This study suggests that high dose vitamin C supplementation might attenuate allergic inflammation in vivo via modulating the Th1/Th2 balance toward the Th1 pole during the Th2-skewed allergic airway inflammation and decreasing eosinophilic infiltration into BALF.

Topics: Animals; Ascorbic Acid; Asthma; Bronchoalveolar Lavage Fluid; Cytokines; Dietary Supplements; Disease Models, Animal; Dose-Response Relationship, Drug; Eosinophils; Female; Humans; Leukemic Infiltration; Mice; Mice, Inbred BALB C; Ovalbumin; Random Allocation; T-Lymphocytes, Helper-Inducer; Th1 Cells; Th2 Cells

Topics: Adult; Aged; Ascorbic Acid; Asthma; beta Carotene; Clinical Trials as Topic; Clinical Trials, Phase I as Topic; Coronary Disease; Disease; Disease Susceptibility; Epidemiologic Factors; Female; Heart Transplantation; Humans; Incidence; Male; Men; Middle Aged; Neoplasms; Pregnancy; Prognosis; Pulmonary Disease, Chronic Obstructive; Risk Factors; Sex Factors

Secretory phospholipases A2 (sPLA2) have functions relevant to asthmatic inflammation, including eicosanoid synthesis and effects on dendritic cells and T cells. The aim of this study was to measure sPLA2 activity in patients with stable and acute asthma and to assess potential associations with body mass index (BMI), and plasma cholesterol and vitamin C concentrations.. Plasma sPLA2 activity and concentrations of cholesterol and vitamin C were measured in 23 control subjects and 61 subjects with stable asthma (42 mild to moderate, 19 severe). In addition, sPLA2 activity was measured in 36 patients experiencing acute asthma and in 22 of these patients after recovery from the acute attack.. sPLA2 activity was not significantly greater in severe (499.9 U; 95% confidence interval (CI) 439.4 to 560.4) compared with mild to moderate asthmatic subjects (464.8; 95% CI 425.3 to 504.3) or control subjects (445.7; 95% CI 392.1 to 499.4), although it was higher in patients with acute asthma (581.6; 95% CI 541.2 to 622.0; p<0.001). Male gender, high plasma cholesterol, increased BMI and atopy were associated with increased sPLA2 activity, while plasma vitamin C was inversely correlated with sPLA2 activity in patients with stable asthma and in control subjects. There were significant interactions between gender and plasma cholesterol and between gender and vitamin C in relation to sPLA2 activity.. Plasma sPLA2 may provide a biological link between asthma, inflammation, increased BMI, lipid metabolism and antioxidants. Interactions among these factors may be pertinent to the pathophysiology and increasing prevalence of both asthma and obesity.

Topics: Acute Disease; Adult; Ascorbic Acid; Asthma; Body Mass Index; Cholesterol; Female; Humans; Male; Middle Aged; Phospholipases A2, Secretory

Even though there is ample evidence on the oxidative stress in asthma, there is limited information on the antioxidant defense systems.. To conduct a comprehensive evaluation of various components of both enzymatic and nonenzymatic antioxidants in a large group of children with asthma.. A total of 164 children with mild asthma and 173 healthy children were included in the study. Levels of the enzymes glutathione peroxidase and superoxide dismutase were measured by using ELISA, whereas reduced glutathione, ascorbic acid, alpha-tocopherol, lycopene, beta-carotene, amino acids participating in glutathione synthesis, and amino acids susceptible to oxidation were measured by HPLC. All comparisons were adjusted for atopy, body mass index, smoke exposure, and pet ownership.. Levels of the enzymes glutathione peroxidase and superoxide dismutase and of the nonenzymatic components of the antioxidant system including reduced glutathione, ascorbic acid, alpha-tocopherol, lycopene, and beta-carotene were significantly lower in children with asthma compared with healthy controls (P < .001 for each). Of the amino acids contributing to glutathione synthesis, glycine and glutamine were significantly lower in children with asthma (P < .001). The majority of the amino acid susceptible to oxidative stress displayed lower levels in children with asthma (P < .05).. Childhood asthma is associated with significant decreases in various components of both enzymatic and nonenzymatic antioxidant defenses.

Topics: Adolescent; alpha-Tocopherol; Amino Acids; Antioxidants; Ascorbic Acid; Asthma; beta Carotene; Carotenoids; Child; Female; Glutathione; Glutathione Peroxidase; Humans; Lycopene; Male; Malondialdehyde; Oxidative Stress; Superoxide Dismutase

Collective evidences reveal that malondialdehyde (MDA), reduced glutathione (GSH) and ascorbic acid can modulate protein glycation. We investigated the concentrations of MDA, GSH, ascorbic acid and protein glycation in asthma patients to delineate the possible association among these parameters.. Blood was collected from 18 asthma patients and 16 age and sex matched control subjects. Glycated hemoglobin (HbA1C), GSH, MDA, vitamin C, fructosamine and glucose were assessed in both groups. The effect of H2O2 on glycation of hemoglobin was studied by incubating normal healthy erythrocytes with either 5 or 50 mmol/l glucose concentration.. Plasma of asthma patients revealed significantly higher concentrations of lipid peroxides and fructosamine concentrations than the matched controls. Glycated hemoglobin concentrations were also found to be significantly increased. Ascorbic acid and GSH concentrations were decreased significantly in the test group when compared with the healthy control group. When the effects of fasting glucose, GSH and ascorbic acid on the concentrations of HbA1C and fructosamine were refuted by partial correlation analysis, MDA was found to be a significant determinant of HbA1c and fructosamine in patients with asthma. The in vitro model with human erythrocytes showed an enhancement of protein glycation by H2O2.. An increased glycation of proteins was found in asthma patients. These data also support the premise that lipid peroxides per se do have a role to play in glycation of hemoglobin and plasma proteins.

Topics: Adult; Ascorbic Acid; Asthma; Blood Glucose; Blood Proteins; Dose-Response Relationship, Drug; Erythrocytes; Female; Fructosamine; Glucose; Glutathione; Glycated Hemoglobin; Glycosylation; Hemoglobins; Humans; Hydrogen Peroxide; Lipid Peroxides; Male; Malondialdehyde; Middle Aged

Several antioxidant nutrients have been reported to be inversely associated with asthma. A study was undertaken to assess the independent associations of these nutrients with asthma in adults.. A nested case-control study was performed in 515 adults with physician diagnosed asthma and 515 matched controls using dietary data obtained from 7 day food diaries. The main outcome measures were physician diagnosed asthma and current symptomatic asthma (diagnosed asthma and self-reported wheeze within the previous 12 months).. Cases were similar to controls in age, sex, social class, and daily energy intake but had a lower median intake of fruit (132.1 v 149.1 g/day, p< or =0.05). 51.5% of the population reported zero consumption of citrus fruit; relative to these individuals, people who consumed >46.3 g/day had a reduced risk of diagnosed and symptomatic asthma (OR adjusted for potential confounders 0.59 (95% CI 0.43 to 0.82) and 0.51 (95% CI 0.33 to 0.79), respectively). In nutrient analysis, dietary vitamin C and manganese were inversely and independently associated with symptomatic asthma (adjusted OR per quintile increase 0.88 (95% CI 0.77 to 1.00) for vitamin C and 0.85 (95% CI 0.74 to 0.98) for manganese), but only manganese was independently associated with diagnosed asthma (OR 0.86 (95% CI 0.77 to 0.95)). Adjusted plasma levels of vitamin C were significantly lower in symptomatic cases than in controls (54.3 v 58.2 micromol/l, p = 0.003).. Symptomatic asthma in adults is associated with a low dietary intake of fruit, the antioxidant nutrients vitamin C and manganese, and low plasma vitamin C levels. These findings suggest that diet may be a potentially modifiable risk factor for the development of asthma.

Topics: Aged; Antioxidants; Ascorbic Acid; Asthma; Case-Control Studies; Cohort Studies; Diet; Energy Intake; Female; Humans; Male; Middle Aged; Risk Factors

There has been growing interest in the role of antioxidant function in controlling inflammatory disease states, such as allergy. This study investigated the relationship between antioxidant status, markers of airways inflammation [exhaled nitric oxide (eNO)], oxidative stress (F(2) isoprostanes) and immune responses in allergic adults.. Antioxidants (vitamins C, E, beta-carotene and selenium) and total antioxidant capacity (tAC) in serum were examined in relation to eNO, plasma F(2) isoprostanes and peripheral blood mononuclear cell (PBMC) cytokine and lymphoproliferative response to house dust mite (HDM) allergen, Staphylococcus enterotoxin B (SEB), phytohaemaglutinin (PHA) and lipopolysaccharide (LPS) in 54 allergic adults.. Firstly, levels of specific vitamins did not correlate with tAC. Secondly, we did not see any evidence that specific vitamin levels (or tAC) were associated with either polarization or attenuation of in vitro immune responses. If anything, there were positive correlations between antioxidant (vitamin C and selenium) levels and HDM allergen responses [lymphoproliferation (selenium; r=0.35, P=0.013) and both Th2 IL13 (vitamin C; tau=0.254, P=0.028) and Th1 IFN-gamma (vitamin C; tau=0.302, P=0.009) responses]. There were also significant positive relationships between antioxidant levels and IL-10 responses to polyclonal stimulation by SEB (r=0.292, P=0.036) and LPS (r=0.34, P=0.015) (beta-carotene) and PHA (r=0.34, P=0.021) (tAC). Thirdly, although airways inflammation (eNO) was associated with both in vitro and in vivo (skin test reactivity) to HDM, we did not see any correlation between eNO and oxidative stress (F(2)-isoprostanes). Finally, there were no consistent relationships between oxidative stress and immune responses.. There was no evidence that higher antioxidant levels were associated with reduced allergen responsiveness in allergic adults. If anything, antioxidant status was associated with increased immune responsiveness. The significance of this needs to be addressed in future intervention studies.

Topics: Adult; Allergens; Antigens, Dermatophagoides; Antioxidants; Ascorbic Acid; Asthma; beta Carotene; Biomarkers; Breath Tests; Enterotoxins; F2-Isoprostanes; Female; Humans; Hypersensitivity; Immunologic Tests; Interleukin-10; Lipopolysaccharides; Lymphocyte Activation; Male; Nitric Oxide; Oxidative Stress; Regression Analysis; Selenium; Vitamin E

Two thousand women were recruited for a prospective investigation of the influence of maternal antioxidant intake in pregnancy on the development of asthma and eczema in children. A food frequency questionnaire was used to characterize diet during pregnancy and blood antioxidant levels were measured. Postal questionnaires were used to follow up the 1,924 singleton children born to the cohort at 6, 12, and 24 months of age. There were no associations between maternal antioxidant intake and wheezing symptoms and eczema in the children's first year. In the children's second year, maternal vitamin E intake during pregnancy was negatively associated with wheeze in the absence of a "cold" (p for trend 0.010) and, in children whose mothers were atopic, there was a negative association between maternal vitamin E intake and childhood eczema (p for trend 0.024). Maternal vitamin C intake during pregnancy was positively associated with "ever wheeze" and eczema during the children's second year. This study suggests that maternal dietary antioxidant intakes during pregnancy may modify the risks of developing wheeze and eczema during early childhood. Further follow up of the cohort will determine whether maternal diet during pregnancy is associated with asthma and atopic disease in later childhood.

Topics: Adult; Antioxidants; Ascorbic Acid; Asthma; Dermatitis, Atopic; Diet; Eczema; Female; Humans; Infant; Infant, Newborn; Logistic Models; Multivariate Analysis; Pregnancy; Prenatal Care; Prevalence; Prospective Studies; Respiratory Sounds; United Kingdom; Vitamin E

The relationship of serum vitamin E, beta-carotene, vitamin C, and selenium to asthma was investigated among 7,505 youth (4-16 years old) in the Third National Health and Nutrition Examination Survey. Logistic regression models adjusted for potentially confounding variables, which generally had no effect on the coefficients for the antioxidants. Serum vitamin E had little or no association with asthma. In separate models, a SD increase in beta-carotene (odds ratio [OR], 0.9; 95% confidence interval [CI], 0.7, 1.0), vitamin C (OR, 0.8; 95% CI, 0.7, 0.9), and selenium (OR, 0.9; 95% CI, 0.7, 1.1) was associated with a 10-20% reduction in asthma prevalence. Serum cotinine was used to identify youth with no cigarette smoke exposure and passive exposure (7%): Active smokers were too few to be studied further. The selenium-asthma association was stronger in youth who were smoke exposed (p = 0.075). A SD increase in selenium was associated with a 50% reduction in asthma prevalence (OR, 0.5; 95% CI, 0.2, 1.4) in youth with passive smoke exposure compared with a 10% reduction in youth with no smoke exposure. The findings support an association of antioxidants with prevalent asthma, which for some antioxidants is stronger among children exposed to cigarette smoke.

Topics: Adolescent; Age Factors; Antioxidants; Ascorbic Acid; Asthma; beta Carotene; Biomarkers; Child; Child, Preschool; Confidence Intervals; Cross-Sectional Studies; Female; Humans; Logistic Models; Male; Odds Ratio; Prevalence; Prognosis; Selenium; Sensitivity and Specificity; Severity of Illness Index; United States; Vitamin E

Dietary intake, especially of antioxidant vitamins A, C, E, and the carotenoids, has been linked with the presence and severity of asthma. From the Third National Health and Nutrition Examination Survey (NHANES III), conducted in the United States between 1988 and 1994, the authors selected 4,093 children (aged 6-17 years) for whom relevant medical, socioeconomic, and anthropometric data were complete. The children were 50.6% female, and 9.7% reported a diagnosis of asthma. Bivariate analyses showed that asthma diagnosis was associated with lower levels of serum vitamin C, alpha-carotene, beta-carotene, and beta-cryptoxanthin. However, antioxidant levels may be surrogate markers for socioeconomic variables such as race, poverty, tobacco exposure, or general nutritional status. In logistic models that included age, body mass index, socioeconomic variables, antioxidant levels, parental asthma, and household smoking, the only antioxidants significantly associated with asthma were vitamin C (odds ratio = 0.72 per mg/dl, 95% confidence interval = 0.55, 0.95) and alpha-carotene (odds ratio = 0.95 per micro g/dl, 95% confidence interval = 0.90, 0.99). The odds ratio for asthma in the highest quintile of serum vitamin C relative to the lowest was 0.65 (p < 0.05), whereas it was 0.74 for alpha-carotene (p = 0.066). The authors concluded that low vitamin C and alpha-carotene intakes are associated with asthma risk in children.

Topics: Adolescent; Ascorbic Acid; Asthma; Body Weight; Carotenoids; Child; Ethnicity; Female; Humans; Logistic Models; Male; Reference Values; Risk Assessment; Risk Factors; Socioeconomic Factors; Tobacco Smoke Pollution; United States; Urban Population; Vitamin A; Vitamin E; Vitamins

Antioxidants may protect the lungs of people with asthma against oxidative stress. Among participants aged > or = 20 years from the Third National Health and Nutrition Examination Survey (1988-1994), we examined serum antioxidant concentrations of 771 persons with current asthma, 352 persons with former asthma, and 15,418 persons without asthma. After adjustment for age, participants with current asthma had similar mean concentrations of vitamin A, retinyl esters, vitamin C, vitamin E, vitamin E/cholesterol ratio, vitamin E/triglyceride ratio, alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, lycopene, and selenium as participants without asthma. We repeated these analyses among participants who did not use vitamin or mineral supplements. After age adjustment, participants with current asthma had lower vitamin C and beta-cryptoxanthin concentrations and a lower mean vitamin E/triglyceride ratio than participants without asthma. In multiple linear regression models that included age, sex, race or ethnicity, education, smoking status, nonhigh-density lipoprotein cholesterol concentration, high-density lipoprotein cholesterol concentration, body mass index, physical activity, and alcohol use, asthma status was not significantly associated with any of the antioxidant concentrations. However, lower vitamin C concentrations were observed among people with current or former asthma than among people who never had asthma (p = 0.014). In the United States, people with asthma do not have manifest antioxidant deficiencies.

Topics: Adult; Antioxidants; Ascorbic Acid; Asthma; Case-Control Studies; Cross-Sectional Studies; Female; Humans; Male; Nutrition Surveys; Osmolar Concentration; United States

Childhood asthma may be affected by dietary changes and increased body mass related to a sedentary lifestyle, although the mechanisms are poorly understood. To test this hypothesis, we used data from the National Health and Nutrition Survey (NHANES III) from 1988-1994, including 7,904 children. We analyzed cross-sectional information on body mass index (BMI = weight/height2), physical activity (hr/day viewing television), dietary intake (24-hr recall), and vitamin C intake (60 mg/day). The probability of self-reported asthma or wheezing relating to risk factors was calculated by logistic regression. After controlling for dietary intake, physical activity, and sociodemographic variables, asthma risk was three times higher for children aged 6-16 years in the highest percentiles of BMI (>95th percentile) when compared to children in percentiles 25-49 (OR = 3.44; 95% CI, 1.49-7.96). No increase was observed in children aged 2-5 years. Low vitamin C intake was marginally related to self-reported current wheezing in children aged 6-16 years. Our results show that increased BMI may influence asthma prevalence in children, but further investigation is needed.

Topics: Adolescent; Age Distribution; Analysis of Variance; Ascorbic Acid; Asthma; Body Mass Index; Child; Child, Preschool; Confidence Intervals; Cross-Sectional Studies; Dietary Supplements; Female; Health Surveys; Humans; Male; Motor Activity; Nutrition Surveys; Odds Ratio; Prevalence; Probability; Prognosis; Risk Assessment; Severity of Illness Index; Sex Distribution

Asthma is primarily an airways inflammatory disease, and the bronchial airways have been shown to be particularly susceptible to oxidant-induced tissue damage. The antioxidant ascorbic acid (AA) plays an essential role in defending against oxidant attack in the airways. Decreased levels of AA have been reported in the plasma and BAL fluid of asthmatics, but not at the site directly proximal to asthma pathology, the bronchial airways. We investigated whether asthmatics have deficient levels of AA in the airways compared to healthy subjects. We performed induced sputum (IS) in a group of mild asthmatics (n = 16) and healthy controls (n = 18) in order to compare constitutive levels of antioxidants in the airways of these two groups. We report that asthmatics had significantly decreased AA in both the cellular (17 +/- 3 ng/10(6) cells vs. 40 +/- 4 ng/10(6) cells) and fluid-phase fraction (616 +/- 152 ng/ml vs. 937 +/- 161 ng/ml) of the IS sample compared to normals. No differences were found with glutathione (GSH) and alpha-tocopherol. These results suggest that AA deficiency may be either an underlying factor in the pathophysiology of asthma or a response to asthmatic airways inflammation.

Topics: Adult; Antioxidants; Ascorbic Acid; Asthma; Female; Humans; Male; Middle Aged; Oxidative Stress; Sputum

Earlier studies in adults have indicated that increased oxidative stress may occur in the blood and airways of asthmatic subjects. Therefore the aim of this study was to compare the concentrations of antioxidants and protein carbonyls in bronchoalveolar lavage fluid of clinically stable atopic asthmatic children (AA, n = 78) with our recently published reference intervals for nonasthmatic children (C, n = 124). Additionally, lipid peroxidation products (malondialdehyde) in bronchoalveolar lavage fluid and several antioxidants in plasma were determined. Bronchoalveolar lavage concentrations (median and interquartile range) of ascorbate [AA: 0.433 (0.294-0.678) versus C: 0.418 (0.253-0.646) micromol/L], urate [AA: 0.585 (0.412-0.996) versus C: 0.511 (0.372-0.687) micromol/L], alpha-tocopherol [AA: 0.025 (0.014-0.031) versus C: 0.017 (0.017-0.260) micromol/L], and oxidized proteins as reflected by protein carbonyls [AA: 1.222 (0.970-1.635) versus C: 1.243 (0.813-1.685) nmol/mg protein] were similar in both groups (p > 0.05 in all cases). The concentration of protein carbonyls correlated significantly with the number of eosinophils, mast cells, and macrophages in AA children only. Concentrations of oxidized proteins and lipid peroxidation products (malondialdehyde) correlated significantly in AA children (r = 0.614, n = 11, p = 0.044). Serum concentrations of ascorbate, urate, retinol, alpha-tocopherol, beta-carotene, and lycopene were similar in both groups whereas alpha-carotene was significantly reduced in asthmatics. Overall, increased bronchoalveolar lavage eosinophils indicate ongoing airway inflammation, which may increase oxidatively modified proteins as reflected by increased protein carbonyl concentrations.

Topics: alpha-Tocopherol; Antioxidants; Ascorbic Acid; Asthma; beta Carotene; Bronchoalveolar Lavage Fluid; Carotenoids; Child; Child, Preschool; Female; Humans; Lipid Peroxidation; Lycopene; Male; Malondialdehyde; Oxidative Stress; Uric Acid; Vitamin A

The most important pathological feature of asthma is airway inflammation, which results in airway hyper-responsiveness. We hypothesized that excessive oxidation is likely to contribute to airway inflammation in asthma. The aim of this study was to evaluate the effects of both acute exposure and a 30-day administration of ascorbic acid (AA), which has an antioxidant effect, on airway responsiveness in sensitized guinea pigs.. Guinea pigs sensitized to ovalbumin (OA), were given drinking water without AA (group 2) or with AA (group 3). The responses of tracheal chains of control animals (group 1) and both groups of sensitized guinea pigs (n = 10, for all groups) to cumulative concentrations of methacholine were measured, and the effective concentrations of methacholine causing 50% of maximum response (EC50 M) were obtained. The response of tracheal chains to 0.1% OA, relative to contraction obtained with 10 micro mol/L methacholine, was also measured. The tracheal responses to methacholine and OA were measured on tissues both incubated and not incubated with AA.. The tracheal responses of group 2 tissues were significantly greater than those of groups 1 and 3 to both OA and methacholine (P < 0.05). There were no significant differences in tracheal responses to OA and methacholine between groups 1 and 3. Acute incubation of tissues caused a reduction of tracheal response to methacholine in all groups, but this was only significantly differ-ent for group 3 (P < 0.05). Acute incubation of tissues did not change tracheal response to OA significantly.. These results showed that although short-term administration of AA had no major effect on tracheal responsiveness among sensitized animals, 30-day administration of AA could lead to a decrease in airway responsiveness of sensitized guinea pigs to both OA and methacholine.

Topics: Analysis of Variance; Animals; Antioxidants; Ascorbic Acid; Asthma; Bronchial Hyperreactivity; Drug Administration Schedule; Guinea Pigs; Male; Methacholine Chloride; Ovalbumin; Trachea

Serum antioxidant status of 50 (19M, 31F) adult asthmatic patients, aged 40 to 50 yr and attending the medical outpatient clinic of the University College Hospital, Ibadan, has been assessed, by measurement of serum ascorbic acid, copper, zinc, albumin, uric acid and magnesium levels, to determine the relationship between antioxidant status and severity of bronchial asthma. Twenty-five (25) age matched adults (10M, 15F) served as controls. The test subjects were classified into two groups (1&2) based on the degree of respiratory distress. Questionnaires were also used to obtain data on subjects' fruit and vegetable intake. Fruit and vegetable intake was similar in patients and controls, 96% and 100% respectively reporting adequate intake. Copper (Cu) level was not significantly different between patients and control subjects, but was significantly higher in female asthmatics than in males (p < 0.05). Magnesium (Mg) level was also lower in asthmatics than in control subject (p < 0.001). Plasma Zinc level was not different between patients and control (p > 0.05). The levels of the other antioxidants, vitamin C, uric acid and albumin were all lower in asthmatics than in controls (p < 0.05, p < 0.001, p < 0.001) respectively. The magnesium level of group 2 (severe asthmatics) was lower than in controls (p < 0.05) unlike moderate asthmatics (group 1) which do not differ significantly from controls. These findings support the emerging concept that antioxidants are consumed in this inflammatory disease and that a corresponding increase in antioxidant supply may improve prognosis for bronchial asthma.

Topics: Adult; Antioxidants; Ascorbic Acid; Asthma; Case-Control Studies; Copper; Female; Fruit; Humans; Magnesium; Male; Middle Aged; Nigeria; Prognosis; Serum Albumin; Severity of Illness Index; Sex Factors; Surveys and Questionnaires; Uric Acid; Vegetables; Zinc

Building on the work of the late John Myers, MD, the author has used an intravenous vitamin-and-mineral formula for the treatment of a wide range of clinical conditions. The modified "Myers' cocktail," which consists of magnesium, calcium, B vitamins, and vitamin C, has been found to be effective against acute asthma attacks, migraines, fatigue (including chronic fatigue syndrome), fibromyalgia, acute muscle spasm, upper respiratory tract infections, chronic sinusitis, seasonal allergic rhinitis, cardiovascular disease, and other disorders. This paper presents a rationale for the therapeutic use of intravenous nutrients, reviews the relevant published clinical research, describes the author's clinical experiences, and discusses potential side effects and precautions.

Topics: Administration, Oral; Adult; Aged; Ascorbic Acid; Asthma; Body Temperature; Calcium Gluconate; Child, Preschool; Depression; Drug Combinations; Fatigue; Female; Fever; Fibromyalgia; Heart Failure; Humans; Hydroxocobalamin; Infusions, Intravenous; Magnesium Chloride; Male; Middle Aged; Migraine Disorders; Pantothenic Acid; Pyridoxine; Respiratory Tract Infections; Vitamin B Complex

The aim of the present study is to evaluate the biochemical parameters in blood relevant to oxygen free radicals and antioxidant defenses in children with asthma. A total of 210 asthmatic children, aged 5-18 years, were studied at two different times, once during a severe episode of wheeze (during episode category) and the other after recovery (resting condition). A total of 180 healthy children participated in the study as age and sex matched healthy controls. Superoxide and hydroxyl radical assays were used as a measure of free radical formation. Antioxidant enzymes and free radical scavengers in blood were also assayed. Lipid peroxidation products were assayed in plasma and erythrocytes to evaluate the imbalance (if any) between oxidant (radical) formation and their inactivation. Serum IgE concentrations and peak expiratory flow rate (PEFR) were used as measures of allergic reactions and residual lung capacity, respectively. Excessive production of superoxide and hydroxyl radicals were noted in the blood cells in asthmatics and were correlated to the severity of disease measured as PEFR. Superoxide dismutase and free radical scavengers in blood were significantly lower in asthma, even during resting condition. The present observations endorse the correlation between disease severity and oxygen radical production in asthma subjects. Oxygen metabolites may play a direct or indirect role in the modulation of airway inflammation. Excessive superoxide and hydroxyl radical production may be used as a marker for susceptibility to asthma and for monitoring therapeutic measures.

Topics: Adolescent; Ascorbic Acid; Asthma; Child; Child, Preschool; Erythrocytes; Female; Free Radicals; Glutathione; Humans; Lipid Peroxidation; Male; Vitamin E

Evidence suggests that the antioxidant vitamin C may play a role in lung function and wheezing, although the data are limited to laboratory evaluation of pulmonary function.. To examine the relationship among serum vitamin C levels, wheezing episodes, and use of health care services.. Analysis of adult subjects (aged > or = 17 years) surveyed in the third National Health and Nutrition Examination Survey (1988-1994) (n = 19,760), including measurements of serum vitamin C levels and self-reports of wheezing episodes, ambulatory health care visits, and overnight hospitalizations for wheezing.. A large proportion of individuals (2377/19,760 [12.0%]) have received a diagnosis of asthma, chronic bronchitis, or emphysema. Among 874 individuals having an ambulatory visit for wheezing, 408 (46.7%) did not have a diagnosed respiratory conditions. Similarly, among 159 individuals hospitalized for wheezing, 61 (38.4%) did not have a diagnosed respiratory condition. Serum vitamin C level had no significant relationship with reported diagnosis of respiratory conditions, episodes of wheezing, or use of health care services for wheezing. In a model computed only with individuals with low or high serum vitamin C levels, after adjustment for potential confounders, no statistically significant relationship was found between serum vitamin C levels and ambulatory care (odds ratio, 0.78; 95% confidence interval, 0.58-1.05) or hospitalization for wheezing episodes (odds ratio, 1.21; 95% confidence interval, 0.67-2.21).. Serum vitamin C levels do not appear to be a marker for use of health care services for wheezing. Future investigations of the role of antioxidants in managing respiratory conditions should focus on the clinically important outcomes of health care use.

Topics: Adult; Aged; Ambulatory Care; Ascorbic Acid; Asthma; Bronchitis; Emphysema; Female; Health Resources; Hospitalization; Humans; Male; Middle Aged; Nutrition Surveys; Odds Ratio; Respiratory Sounds; United States

Lung lining fluid ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) concentrations are low in patients with mild asthma even though blood levels are normal or increased. These findings, along with the presence of increased amounts of oxidised glutathione in their airways, indicate that patients with asthma are subject to increased oxidative stress.

Topics: Antioxidants; Ascorbic Acid; Asthma; Bronchoalveolar Lavage Fluid; Chromatography, High Pressure Liquid; Glutathione; Humans; Lung; Oxidation-Reduction; Reference Values; Vitamin E

A role for diet in the pathophysiology of asthma may be mediated by altered immune or antioxidant activity with consequent effects on airway inflammation. We evaluated associations between several dietary factors assessed by a semiquantitative food frequency questionnaire, and incidence of asthma over a 10-yr period in 77,866 women 34 to 68 yr of age. Women in the highest quintile of vitamin E intake from diet, but not from supplements, had a risk of 0.53 (95% confidence interval [CI] = 0.33 to 0.86) compared with women in the lowest quintile. This relationship, however, was attenuated when the contribution from nuts, a major source of vitamin E in these data and a possible allergen, was removed (relative risk = 0.74 [0.50 to 1.10], p for trend = 0.007). Positive associations were found for vitamins C and E from supplements, but appeared to be explained by women at high risk of asthma initiating use of vitamin supplements prior to diagnosis. A nonsignificant inverse association with carotene intake was noted, but no clear relations with asthma were demonstrated for intake of linoleic acid or omega-3 fatty acids. These data suggest that antioxidant supplementation and intake of various fats during adulthood are not important determinants of asthma, although vitamin E from diet may have a modest protective effect.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Asthma; Cohort Studies; Diet; Fatty Acids; Female; Humans; Middle Aged; Prospective Studies; Smoking; Vitamin A; Vitamin E

Reduced levels of glutathione peroxidase (GSH-Px) have been observed in adults with asthma. This study examines the antioxidant status in children with asthma compared with a control group in a cross-sectional analysis. Red blood cell GSH-Px, superoxide dismutase (SOD), and plasma concentrations of retinol, vitamin C, alpha tocopherol, and cholesterol were measured in 37 subjects (26 males) with stable controlled asthma. Thirty-five subjects (20 males) without eczema, hayfever, or recurrent respiratory symptoms were used as a control group. Children with asthma had significantly reduced red blood cell GSH-Px activity compared with controls [median (inter-quartile range) for asthma group, 10.25 (9.25-11.91); for control group, 11.75 (10.34-12.26) IU/g Hb; P = 0.006]. There were no significant differences in activity of SOD or vitamin C, retinol, or alpha tocopherol/cholesterol ratio. The reduction in GSH-Px activity may have therapeutic and etiological implications for asthma. The effects of disease activity and treatment on antioxidant status needs for further study.

Topics: Adolescent; Antioxidants; Ascorbic Acid; Asthma; Case-Control Studies; Child; Child, Preschool; Cross-Sectional Studies; Erythrocytes; Female; Glutathione Peroxidase; Humans; Infant; Male; Superoxide Dismutase; Vitamin A; Vitamin E

A novel antiasthmatic, 2-[(4-hydroxyphenyl)amino]-5-methoxybenzenemethanol (1), oxidizes to the corresponding iminoquinone in aqueous solutions. The reaction was monitored by a paired-ion reversed-phase HPLC method. The oxidation rate was highly dependent on the solution pH, with a large rate increase occurring above pH 6.1. In nonaqueous solution, the oxidation reaction was significantly slower. Ascorbic acid protects 1 from oxidation. The aqueous solution of the decomposed product is reduced to 1 in the presence of ascorbic acid.

Topics: Aminophenols; Ascorbic Acid; Asthma; Benzyl Alcohols; Chromatography, High Pressure Liquid; Hydrogen-Ion Concentration; Kinetics; Lactates; Oxidation-Reduction; Phosphates; Solutions; Spectrophotometry, Ultraviolet; Sulfites

Desensitization with HDM manufactured by Bencard was carried out in a group of 20 children with bronchial asthma showing hypersensitivity to Dermatophagoides pteronyssimus allergen in prick skin tests. Ten randomly selected children treated symptomatically and with climate served as a control group. Children were examined clinically before and after desensitization. Clinical improvement was observed 15 months after desensitization together with weakened delayed bronchial response to allergen inhalation. No significant difference in patency of airway was seen in both groups. Differences in serum IgE and IgG levels and mean eosinophilia in the peripheral blood were statistically insignificant.

Topics: Ascorbic Acid; Asthma; Child; Desensitization, Immunologic; Drug Combinations; Female; Humans; Immunoglobulin E; Immunoglobulin G; Male; Pulmonary Ventilation; Vitamin B Complex

The pharmacological therapy of asthmatic syndromes is based essentially on the programmed use of disodium cromoglycate, beta-2-stimulants, antimuscarinics, theophyllines and corticosteroids. However, the continual progress being made in pathogenesis and pharmacology suggests, to an ever-increasing extent, the application of new therapeutic approaches for these diseases, some of which are fairly interesting from a speculative point of view although they are as yet of limited practical value. Calcium antagonists and alpha-blockers have a mild anti-reactive effect but this is not sufficiently potent to justify use of these products in the treatment of asthma unless there are also cardiovascular disorders for which these drugs are particularly indicated. Despite the initial promising prospects, all attempts to obtain PGE analogues of therapeutic value as antiasthmatics have proved fruitless. Research into orally active chromone derivatives has proved equally unproductive. On the other hand, certain new inhalatory chromones are decidedly more promising. Specific antagonization of mediators (histamine, prostaglandin, leukotrienes) did not produce the effect hoped for in asthma, but this was foreseeable insofar as the major pathogenic mediators are too vast in number (and no doubt there are still many more to be discovered) to allow one to conceive it possible to achieve a satisfactory therapeutic effect by merely blocking some of them. Inflammation of the bronchial wall is currently considered to be one of the basic pathogenic factors provoking the recurrence of asthma: this is proved indirectly by the potent antiasthmatic effect of corticosteroids which are the most effective anti-inflammatory agents. As regards nonsteroidal anti-inflammatory drugs (NSAID), however, matters are more complicated.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adrenal Cortex Hormones; Adrenergic alpha-Agonists; Ascorbic Acid; Asthma; Bronchitis; Calcium Channel Blockers; Chromones; Cromolyn Sodium; Humans; Lung Diseases, Obstructive; Prostaglandins E

Topics: Arachidonic Acids; Ascorbic Acid; Asthma; Biological Transport, Active; Epidemiologic Methods; Evaluation Studies as Topic; Fatty Acids, Unsaturated; Humans; Lung; Prostaglandins; Respiratory Physiological Phenomena

We studied the effect of ascorbic acid in 14 mild asthmatic subjects. The effect of ascorbic acid (1.0 g orally) was assessed by the changes in concentration of methacholine required to decrease the specific airway conductance by 40% (pD40). Ascorbic acid increased pD40 from control values of 9.38 +/- 1.97 mg/ml (mean +/- SEM) to 12.59 mg/ml +/- 2.52 (p less than 0.05). Administration of 50 mg of indomethacin, orally, reversed the effect of ascorbic acid. Indomethacin alone had no effect on the mean pD40. The results suggest that ascorbic acid exerts its effect via alteration of arachidonic acid metabolism.

Topics: Adult; Airway Resistance; Ascorbic Acid; Asthma; Bronchial Provocation Tests; Dose-Response Relationship, Drug; Female; Humans; Indomethacin; Male; Methacholine Compounds

Twenty subjects with mild asthma took a short course of moderately high doses of Vitamin C (500 mg four times daily for 3 days and 1 g prior to spirometric evaluation). There were no differences in pulmonary functions just prior to and after therapy. There were no adverse reactions noted. If, as reported, Vitamin C has a beneficial effect in asthma, it does not appear to be due to a bronchodilatory effect.

Topics: Adult; Ascorbic Acid; Asthma; Bronchi; Female; Humans; Male; Middle Aged; Respiratory Function Tests

The stimulatory effects of ascorbate on neutrophil motility in vitro and in vivo and lymphocyte transformation to mitogens following ingestion or intravenous injection of ascorbate have been found to be related entirely to inhibition of the autooxidative effect of the myeloperoxidase/hydrogen peroxide/halide system (MPO/H2O2/halide system). Stimulation of neutrophil migration and lymphocyte transformation following a single intravenous injection of 1 g of ascorbate was associated with inhibition of the MPO/H2O2/halide system. The immunostimulatory activity and peroxidase inhibitory activity was related entirely to the serum ascorbate level. The relationship between inhibition of the peroxidase/h2O2/halide system and stimulation of neutrophil motility and lymphocyte mitogen-induced transformation was further established by using the horseradish peroxidase (HRP)/H2O2/halide system in vitro. Neutrophils and lymphocytes, exposed to this system, manifested markedly impaired chemotactic responsiveness and mitogen-induced transformation, respectively. However inclusion of ascorbate with the peroxidative system protected the neutrophils and lymphocytes from these inhibitory effects. Further studies in 3 patients with chronic granulomatous disease (CGD) and 10 patients with bronchial asthma suggested that ascorbate may be of value to improve the primary immunological abnormalities (neutrophil motility and antimicrobial activity) in CGD and the secondary abnormalities (neutrophil motility and lymphocyte transformation) found in some individuals with bronchial asthma.

Topics: Antibody Formation; Ascorbic Acid; Asthma; Child; Humans; Leprosy; Leukocytes; Lymphomatoid Granulomatosis; Neutrophils; Time Factors

Ten White children with bronchial asthma and exercise-induced bronchoconstriction were assessed immunologically before and 1, 3 and 6 months after the commencement of standard therapy supplemented with ascorbate 1 g/d. The tests of cellular immune function were neutrophil chemotaxis, phagocytosis and resting and stimulated nitroblue tetrazolium reduction, and lymphocyte mitogen-induced transformation. Humoral functions measured were secretory IgA, serum immunoglobulins, alpha 1-antitrypsin, C3, C4 and total haemolytic complement, antistreptolysin O (ASO) and C-reactive protein. Radio-allergosorbent testing to the common allergens Cynodon dactylon (grass), Dermatophagoides pteronyssinus (mite), house dust and cat epithelium was performed on each child before and 3 and 6 months after treatment. Two children had depressed neutrophil motility, 4 had depressed lymphocyte transformation, and 7 had elevated levels of ASO. These functions normalized after 6 months of ascorbate-supplemented therapy. Serum total IgE levels but not specific IgE levels were likewise reduced after 6 months of therapy. Reduced levels of serum alpha 1-antitrypsin were observed in 2 children, and remained unchanged throughout the study.

Topics: Antibody Formation; Ascorbic Acid; Asthma; Chemotaxis, Leukocyte; Child; Drug Therapy, Combination; Female; Humans; Immunity, Cellular; Immunoglobulins; Lymphocyte Activation; Male; Neutrophils; Pulmonary Ventilation; Time Factors

Plasma cholesterol, plasma and white blood cell ascorbic acid concentrations were estimated in 30 untreated, 32 salbutamol-treated patients with bronchial asthma and in 57 normal controls. Treated and untreated asthmatics had significantly higher plasma cholesterol but lower plasma and white cell ascorbic acid levels than normal controls. A negative correlation was found between white cell ascorbic acid level and plasma cholesterol concentration in both treated and untreated asthmatics. These findings are discussed.

Topics: Adult; Age Factors; Albuterol; Ascorbic Acid; Asthma; Body Weight; Cholesterol; Humans; Leukocyte Count; Leukocytes

Controlled standardised histamine inhalation tests were carried out in 21 asthmatics to determine the degree of non-specific bronchial hyperreactivity with and without prior treatment with several anti-asthmatic drugs. A significant protective effect was produced by inhaled salbutamol, 200 microgram, ingested salbutamol, 4 mg, inhaled Sch1000, 40 microgram inhaled atropine sulphate, 290 microgram, and ingested choline theophylinate (200 or 400 mg) producing serum theophylline levels over 10 mg/l. Inhaled salbutamol was consistently the most effective and was significantly better than the other drugs. The protective effect between the other four was not significantly different. Drug side-effects occurred only with the ingested drugs. No significant protection was detected after ingested choline theophyllinate producing serum theophylline levels of less than 10 mg/l, inhaled sodium cromoglycate, 20 mg given once or six-hourly for one week, or ingested ascorbic acid, 1 gram.

Topics: Albuterol; Ascorbic Acid; Asthma; Atropine; Choline; Cromolyn Sodium; Female; Histamine; Humans; Ipratropium; Male

Topics: Ascorbic Acid; Asthma; Constriction, Pathologic; Histamine; Theophylline

Topics: Ascorbic Acid; Aspirin; Asthma; Calcium; Citrates; Coronary Disease; Depression, Chemical; Diabetes Mellitus; Duodenal Ulcer; Dwarfism, Pituitary; Emphysema; Facial Paralysis; Gluconates; Histamine H1 Antagonists; Humans; Hypertension; Hyperthyroidism; Kidney Calculi; Liver Diseases, Parasitic; Magnesium; Oxalates; Phosphates; Pyridoxine; Schistosomiasis; Stimulation, Chemical; Terpenes; Tuberculosis, Pulmonary

Topics: Administration, Oral; Adult; Aged; Ascorbic Acid; Aspirin; Asthma; Drug Combinations; Female; Histamine H1 Antagonists; Humans; Male; Middle Aged; Piperazines; Respiratory Insufficiency; Rhinitis, Allergic, Seasonal; Triamcinolone

Topics: Ascorbic Acid; Aspirin; Asthma; Humans; Piperazines; Triamcinolone

Topics: Adolescent; Aerosols; Ascorbic Acid; Asthma; Biomedical Research; Bronchodilator Agents; Child; Drug Therapy; Geriatrics; Humans; Infant; Infant, Newborn; Isoproterenol; Placebos; Propylene Glycols

Topics: Ascorbic Acid; Aspirin; Asthma; Cell- and Tissue-Based Therapy; Child; Ephedrine; Immunotherapy, Active; Theophylline

Topics: Ammonium Compounds; Anti-Infective Agents, Local; Ascorbic Acid; Asthma; Bronchitis; Germany; Germany, West; Humans; Hydrocortisone; Hypercholesterolemia; Isoproterenol; Pentylenetetrazole; Pulmonary Emphysema; Quaternary Ammonium Compounds; Reserpine; Synephrine; Thyroxine

Topics: Anti-Allergic Agents; Ascorbic Acid; Asthma; Histamine H1 Antagonists; Prednisone; Vitamins

Topics: Adenosine Triphosphate; Adrenocorticotropic Hormone; Ascorbic Acid; Asthma; Vitamins

Topics: Adenosine Triphosphate; Adrenocorticotropic Hormone; Ascorbic Acid; Asthma; Humans; Vitamins

Topics: Adenosine Triphosphate; Adrenocorticotropic Hormone; Ascorbic Acid; Asthma; Humans; Vitamins

Topics: Acclimatization; Adaptation, Physiological; Ascorbic Acid; Asthma; Desoxycorticosterone; Vitamins

Topics: Airway Obstruction; Ascorbic Acid; Asthma; Humans; Vitamins

Topics: Ascorbic Acid; Asthma; Humans; Vitamins

Topics: Amyloid; Amyloidosis; Ascorbic Acid; Asthma; Cortisone; Nephrosis; Uremia; Vitamins

Topics: Ascorbic Acid; Asthma; Humans; Vitamins

Topics: Ascorbic Acid; Asthma; Calcium; Calcium Compounds; Calcium, Dietary; Gluconates