Breath alkanes as a marker of oxidative stress in different clinical conditions

Volatilomes of human infection

The human volatilome comprises a vast mixture of volatile emissions produced by the human body and its microbiomes. Following infection, the human volatilome undergoes significant shifts, and presents a unique medium for non-invasive biomarker discovery. In this review, we examine how the onset of infection impacts the production of volatile metabolites that reflects dysbiosis by pathogenic microbes. We describe key analytical workflows applied across both microbial and clinical volatilomics and emphasize the value in linking microbial studies to clinical investigations to robustly elucidate the metabolic species and pathways leading to the observed volatile signatures. We review the current state of the art across microbial and clinical volatilomics, outlining common objectives and successes of microbial-clinical volatilomic workflows. Finally, we propose key challenges, as well as our perspectives on emerging opportunities for developing clinically useful and targeted workflows that could significantly enhance and expedite current practices in infection diagnosis and monitoring.

Identification of Volatile Markers of Colorectal Cancer from Tumor Tissues Using Volatilomic Approach

The human body releases numerous volatile organic compounds (VOCs) through tissues and various body fluids, including breath. These compounds form a specific chemical profile that may be used to detect the colorectal cancer CRC-related changes in human metabolism and thereby diagnose this type of cancer. The main goal of this study was to investigate the volatile signatures formed by VOCs released from the CRC tissue. For this purpose, headspace solid-phase microextraction gas chromatography-mass spectrometry was applied. In total, 163 compounds were detected. Both cancerous and non-cancerous tissues emitted 138 common VOCs. Ten volatiles (2-butanone; dodecane; benzaldehyde; pyridine; octane; 2-pentanone; toluene; p-xylene; n-pentane; 2-methyl-2-propanol) occurred in at least 90% of both types of samples; 1-propanol in cancer tissue (86% in normal one), acetone in normal tissue (82% in cancer one). Four compounds (1-propanol, pyridine, isoprene, methyl thiolacetate) were found to have increased emissions from cancer tissue, whereas eleven showed reduced release from this type of tissue (2-butanone; 2-pentanone; 2-methyl-2-propanol; ethyl acetate; 3-methyl-1-butanol; d-limonene; tetradecane; dodecanal; tridecane; 2-ethyl-1-hexanol; cyclohexanone). The outcomes of this study provide evidence that the VOCs signature of the CRC tissue is altered by the CRC. The volatile constituents of this distinct signature can be emitted through exhalation and serve as potential biomarkers for identifying the presence of CRC. Reliable identification of the VOCs associated with CRC is essential to guide and tune the development of advanced sensor technologies that can effectively and sensitively detect and quantify these markers.

Breath analysis combined with cardiopulmonary exercise testing and echocardiography for monitoring heart failure patients: the AEOLUS protocol

This paper describes the AEOLUS pilot study which combines breath analysis with cardiopulmonary exercise testing (CPET) and an echocardiographic examination for monitoring heart failure (HF) patients. Ten consecutive patients with a prior clinical diagnosis of HF with reduced left ventricular ejection fraction were prospectively enrolled together with 15 control patients with cardiovascular risk factors, including hypertension, type II diabetes or chronic ischemic heart disease. Breath samples were collected at rest and during CPET coupled with exercise stress echocardiography (CPET-ESE) protocol by means of needle trap micro-extraction and were analyzed through gas-chromatography coupled with mass spectrometry. The protocol also involved using of a selected ion flow tube mass spectrometer for a breath-by-breath isoprene and acetone analysis during exercise. At rest, HF patients showed increased breath levels of acetone and pentane, which are related to altered oxidation of fatty acids and oxidative stress, respectively. A significant positive correlation was observed between acetone and the gold standard biomarker NT-proBNP in plasma (r= 0.646,p< 0.001), both measured at rest. During exercise, some exhaled volatiles (e.g., isoprene) mirrored ventilatory and/or hemodynamic adaptation, whereas others (e.g., sulfide compounds and 3-hydroxy-2-butanone) depended on their origin. At peak effort, acetone levels in HF patients differed significantly from those of the control group, suggesting an altered myocardial and systemic metabolic adaptation to exercise for HF patients. These preliminary data suggest that concomitant acquisition of CPET-ESE and breath analysis is feasible and might provide additional clinical information on the metabolic maladaptation of HF patients to exercise. Such information may refine the identification of patients at higher risk of disease worsening.

Potential Role of Oxidative Stress in the Production of Volatile Organic Compounds in Obesity

Obesity is associated with numerous health issues such as sleep disorders, asthma, hepatic dysfunction, cancer, renal dysfunction, diabetes, cardiovascular complications, and infertility. Previous research has shown that the distribution of excess body fat, rather than excess body weight, determines obesity-related risk factors. It is widely accepted that abdominal fat is a serious risk factor for illnesses associated with obesity and the accumulation of visceral fat promotes the release of pro-oxidants, pro-inflammatory, and reactive oxygen species (ROS). The metabolic process in the human body produces several volatile organic compounds (VOCs) via urine, saliva, breath, blood, skin secretions, milk, and feces. Several studies have shown that VOCs are released by the interaction of ROS with underlying cellular components leading to increased protein oxidation, lipid peroxidation, or DNA damage. These VOCs released via oxidative stress in obese individuals may serves as a biomarker for obesity-related metabolic alterations and disease. In this review, we focus on the relationship between oxidative stress and VOCs in obesity.

Analysis of the volatile organic compounds of epidural analgesia-ameliorated metabolic disorder in pregnant women with gestational diabetes mellitus based on untargeted metabolomics

Gestational diabetes mellitus (GDM) is a metabolic disease with an increasing annual incidence. Our previous observational study found that pregnant women with gestational diabetes had mild cognitive decline, which may be related to methylglyoxal (MGO). This study aimed to investigate whether labor pain aggravates the increase in MGO and explored the protective effect of epidural analgesia on metabolism in pregnant women with GDM based on solid-phase microextraction gas chromatography/mass spectrometry (SPME/GC-MS). Pregnant women with GDM were divided into a natural birth group (ND group, n = 30) and epidural analgesia group (PD group, n = 30). After fasting for ≥ 10 h overnight, venous blood samples were collected pre- and post-delivery to detect MGO, interleukin-6 (IL-6), and 8-epi-prostaglandin F2 alpha (8-iso-PGF2α) by ELISA. Serum samples were analyzed for volatile organic compounds (VOCs) using SPME-GC-MS. MGO, IL-6, and 8-iso-PGF2α levels in the ND group increased significantly post-delivery (P < 0.05) and were significantly higher in this group than the levels in the PD group (P < 0.05). Compared to the PD group, VOCs in the ND group increased significantly post-delivery. Further results indicated that propionic acid may be associated with metabolic disorders in pregnant women with GDM. Epidural analgesia can effectively improve the metabolism and immune function in pregnant women with GDM.

The Prognostic Value of Derivatives-Reactive Oxygen Metabolites (d-ROMs) for Cardiovascular Disease Events and Mortality: A Review

Oxidative stress participates in the development and exacerbation of cardiovascular diseases (CVD). The ability to promptly quantify an imbalance in an individual reductive-oxidative (RedOx) state could improve cardiovascular risk assessment and management. Derivatives-reactive oxygen metabolites (d-ROMs) are an emerging biomarker of oxidative stress quantifiable in minutes through standard biochemical analysers or by a bedside point-of-care test. The current review evaluates available data on the prognostic value of d-ROMs for CVD events and mortality in individuals with known and unknown CVD. Outcome studies involving small and large cohorts were analysed and hazard ratio, risk ratio, odds ratio, and mean differences were used as measures of effect. High d-ROM plasma levels were found to be an independent predictor of CVD events and mortality. Risk begins increasing at d-ROM levels higher than 340 UCARR and rises considerably above 400 UCARR. Conversely, low d-ROM plasma levels are a good negative predictor for CVD events in patients with coronary artery disease and heart failure. Moreover, combining d-ROMs with other relevant biomarkers routinely used in clinical practice might support a more precise cardiovascular risk assessment. We conclude that d-ROMs represent an emerging oxidative-stress-related biomarker with the potential for better risk stratification both in primary and secondary cardiovascular prevention.

Volatilomic Signatures of AGS and SNU-1 Gastric Cancer Cell Lines

In vitro studies can help reveal the biochemical pathways underlying the origin of volatile indicators of numerous diseases. The key objective of this study is to identify the potential biomarkers of gastric cancer. For this purpose, the volatilomic signatures of two human gastric cancer cell lines, AGS (human gastric adenocarcinoma) and SNU-1 (human gastric carcinoma), and one normal gastric mucosa cell line (GES-1) were investigated. More specifically, gas chromatography mass spectrometry has been applied to pinpoint changes in cell metabolism triggered by cancer. In total, ten volatiles were found to be metabolized, and thirty-five were produced by cells under study. The volatiles consumed were mainly six aldehydes and two heterocyclics, whereas the volatiles released embraced twelve ketones, eight alcohols, six hydrocarbons, three esters, three ethers, and three aromatic compounds. The SNU-1 cell line was found to have significantly altered metabolism in comparison to normal GES-1 cells. This was manifested by the decreased production of alcohols and ketones and the upregulated emission of esters. The AGS cells exhibited the increased production of methyl ketones containing an odd number of carbons, namely 2-tridecanone, 2-pentadecanone, and 2-heptadecanone. This study provides evidence that the cancer state modifies the volatilome of human cells.

Effects of long-term vegan diet on breath composition

The composition of exhaled breath derives from an intricate combination of normal and abnormal physiological processes that are modified by the consumption of food and beverages, circadian rhythms, bacterial infections, and genetics as well as exposure to xenobiotics. This complexity, which results wide intra- and inter-individual variability and is further influenced by sampling conditions, hinders the identification of specific biomarkers and makes it difficult to differentiate between pathological and nominally healthy subjects. The identification of a "normal" breath composition and the relative influence of the aforementioned parameters would make breath analyses much faster for diagnostic applications. We thus compared, for the first time, the breath composition of age-matched volunteers following a vegan and a Mediterranean omnivorous diet in order to evaluate the impact of diet on breath composition. Mixed breath was collected from 38 nominally healthy volunteers who were asked to breathe into a two-liter handmade Nalophan bag. Exhalation flow rate and carbon dioxide values were monitored during breath sampling. An aliquot (100 mL) of breath was loaded into a sorbent tube (250 mg of Tenax GR, 60/80 mesh) before being analyzed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Breath profiling using TD-GC-MS analysis identified five compounds (methanol, 1-propanol, pentane, hexane, and hexanal), thus enabling differentiation between samples collected from the different group members . Principal component analysis showed a clear separation between groups, suggesting that breath analysis could be used to study the influence of dietary habits in the fields of nutrition and metabolism. Surprisingly, one Italian woman and her brother showed extremely low breath isoprene levels (about 5 ppbv), despite their normal lipidic profile and respiratory data, such as flow rate and pCO2. Further investigations to reveal the reasons behind low isoprene levels in breath would help reveal the origin of isoprene in breath.

Secondary electrospray ionization-high resolution mass spectrometry (SESI-HRMS) fingerprinting enabled treatment monitoring of pulmonary carcinoma cells in real time

Lung cancer is one of the leading causes of cancer related deaths in the United States. A novel volatile analysis platform is needed to complement current diagnostic techniques and better elucidate chemical signatures of lung cancer and subsequent treatments. A systems biology bottom-up approach using cell culture volatilomics was employed to identify pathological volatile fingerprints of lung cancer in real time. An advanced secondary electrospray ionization (SESI) source, named SuperSESI was used in this study and directly attached to a Thermo Q-Exactive high-resolution mass spectrometer (HRMS). We performed a series of experiments to determine if our optimized SESI-HRMS platform can distinguish between cancer types by sampling their in vitro volatilome profiles. We detected 60 significant volatile organic compound (VOC) features in positive mode that were deemed of cancer cell origin. The cell derived features were used for subsequent analyses to distinguish between our two studied lung cancer types, non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Partial least squares-discriminant analysis (PLS-DA) model revealed a good separation of the two cancer types, suggesting unique chemical composition of their headspace profiles. A receiver operating characteristic (ROC) curve using 10 prominent features was used to predict disease type, with an area under the curve (AUC) of 0.811. Cultures were also treated with cisplatin to determine the feasibility of classifying drug treatment from expelled gases. A PLS-DA model revealed independent clustering based on their headspace profiles. An ROC curve using the top features driving separation of PLS-DA model suggested good accuracy with an AUC of 1. It is thus possible to benefit from the advantages of this platform to distinguish the unique volatile fingerprints of cancers to uncover potential biomarkers for cancer type differentiation and treatment monitoring.

Computational Design of MOF-Based Electronic Noses for Dilute Gas Species Detection: Application to Kidney Disease Detection

The diverse chemical composition of exhaled human breath contains a vast amount of information about the health of the body, and yet this is seldom taken advantage of for diagnostic purposes due to the lack of appropriate gas-sensing technologies. In this work, we apply computational methods to design mass-based gas sensor arrays, often called electronic noses, that are optimized for detecting kidney disease from breath, for which ammonia is a known biomarker. We define combined linear adsorption coefficients (CLACs), which are closely related to Henry's law coefficients, for calculating gas adsorption in metal-organic frameworks (MOFs) of gases commonly found in breath (i.e., carbon dioxide, argon, and ammonia). These CLACs were determined computationally using classical atomistic molecular simulation techniques and subsequently used to design and evaluate gas sensor arrays. We also describe a novel numerical algorithm for determining the composition of a breath sample given a set of sensor outputs and a library of CLACs. After identifying an optimal array of five MOFs, we screened a set of 100 simplified computer-generated, water-free breath samples for kidney disease and were able to successfully quantify the amount of ammonia in all samples within the tolerances needed to classify them as either healthy or diseased, demonstrating the promise of such devices for disease detection applications.

Volatile organic compounds (VOCs) in exhaled breath as a marker of hypoxia in multiple chemical sensitivity

In the history of diagnostics, breath analysis was one of the first method used until the breakthrough of biochemical testing technology. Today, breath analysis has made a comeback with the development of gas analyzers and e‐noses, demonstrating its power in its applicability for diagnosing a wide range of diseases. The physical basis of multiple chemical sensitivity (MCS), an emerging environmental disease, is difficult to understand because it is based on the scenario of chronic hypoxia, with a complex of chemical compounds that trigger the syndrome and result in multiple symptoms.

The aim of this study was to investigate MCS by analyzing exhaled volatile organic compounds (VOCs). The volatile, metabolic picture could be a putative gold standard for understanding and diagnosing the disease. The study was based on recording in resting condition using the noninvasive passive e‐nose contactless breath test, the Olfactory Real‐Time Volatile Organic Compounds (ORT‐VOC) test in MCS, and control samples. The VOCs profile distinguished between disease and health. It also distinguished the gender‐related volatile profile with significant robustness. The results trace a putative compensatory physiological pathway elicited by increased lactate, leading to acidosis, and hyperventilation, resulting in the production of specific VOCs. We conclude that breath testing is a valuable tool to investigate the hypoxia‐related VOC profile, facilitating MCS diagnosis.

Volatile Organic Compounds in Exhaled Breath as Fingerprints of Lung Cancer, Asthma and COPD

Lung cancer, chronic obstructive pulmonary disease (COPD) and asthma are inflammatory diseases that have risen worldwide, posing a major public health issue, encompassing not only physical and psychological morbidity and mortality, but also incurring significant societal costs. The leading cause of death worldwide by cancer is that of the lung, which, in large part, is a result of the disease often not being detected until a late stage. Although COPD and asthma are conditions with considerably lower mortality, they are extremely distressful to people and involve high healthcare overheads. Moreover, for these diseases, diagnostic methods are not only costly but are also invasive, thereby adding to people’s stress. It has been appreciated for many decades that the analysis of trace volatile organic compounds (VOCs) in exhaled breath could potentially provide cheaper, rapid, and non-invasive screening procedures to diagnose and monitor the above diseases of the lung. However, after decades of research associated with breath biomarker discovery, no breath VOC tests are clinically available. Reasons for this include the little consensus as to which breath volatiles (or pattern of volatiles) can be used to discriminate people with lung diseases, and our limited understanding of the biological origin of the identified VOCs. Lung disease diagnosis using breath VOCs is challenging. Nevertheless, the numerous studies of breath volatiles and lung disease provide guidance as to what volatiles need further investigation for use in differential diagnosis, highlight the urgent need for non-invasive clinical breath tests, illustrate the way forward for future studies, and provide significant guidance to achieve the goal of developing non-invasive diagnostic tests for lung disease. This review provides an overview of these issues from evaluating key studies that have been undertaken in the years 2010–2019, in order to present objective and comprehensive updated information that presents the progress that has been made in this field. The potential of this approach is highlighted, while strengths, weaknesses, opportunities, and threats are discussed. This review will be of interest to chemists, biologists, medical doctors and researchers involved in the development of analytical instruments for breath diagnosis.

Rats Sniff Off Toxic Air

Breathing air is a fundamental human need, yet its safety, when challenged by various harmful or lethal substances, is often not properly guarded. For example, air toxicity is currently monitored only for a single or a limited number of known toxicants, thus failing to warn against possible hazardous air fully. Here, we discovered that, within minutes, living rats emitted distinctive profiles of volatile organic compounds (VOCs) via breath when exposed to various airborne toxicants such as endotoxin, O₃, ricin, and CO₂. Compared to background indoor air, when exposed to ricin or endotoxin aerosols, breath-borne VOC levels, especially that of carbon disulfide, were shown to decrease, while their elevated levels were observed for exposure to O₃ and CO₂. A clear contrast in breath-borne VOC profiles of rats exposed to different toxicants was observed with a statistical significance. Differences in microRNA regulations such as miR-33, miR-146a, and miR-155 from rats' blood samples revealed different mechanisms used by rats in combating different air toxicant challenges. Similar to dogs, rats were found here to be able to sniff off toxic air by releasing a specific breath-borne VOC profile. The discovered science opens a new arena for online monitoring of air toxicity and health effects of pollutants.

Diagnosis of Human Echinococcosis via Exhaled Breath Analysis: A Promise for Rapid Diagnosis of Infectious Diseases Caused by Helminths

Background

Human echinococcosis is a neglected infectious disease affecting more than 1 million people globally. Its diagnosis is expensive and difficult because of lack of adequate resources in low-resource locations, where most cases occur.

Methods

A group of volunteers diagnosed with the 2 main types of echinococcosis and corresponding control groups were recruited from hospitals in Tunisia (32 patients with cystic echinococcosis and 43 controls) and Poland (16 patients with alveolar echinococcosis and 8 controls). Breath samples were collected from all patients and analyzed by gas chromatography coupled to mass spectrometry, and a specifically developed electronic nose system.

Results

The chemical analysis revealed statistically different concentrations of 2 compounds in the breath of patients with cystic echinococcosis compared to controls, and statistically different concentrations of 7 compounds in the breath of patients with alveolar echinococcosis compared to controls. The discrimination accuracy achieved by the electronic nose system was 100% for cystic echinococcosis and 92.9% for alveolar echinococcosis, while the discrimination accuracy between these 2 patient groups was 92.1%.

Conclusion

Here we advocate a noninvasive, fast, easy-to-operate and nonexpensive diagnostic tool for the diagnosis of human echinococcosis disease through exhaled breath analysis, suitable for early diagnosis and population screening.

A volatile biomarker in breath predicts lung cancer and pulmonary nodules

BACKGROUND

previous studies have reported volatile organic compounds (VOCs) in the breath as apparent biomarkers of lung cancer. We tested the hypothesis that a robust breath VOC biomarker of lung cancer should also predict pulmonary nodules in chest CT images.

METHODS

Biomarker discovery study (unblinded): 301 subjects were screened for lung cancer with low dose chest CT (LDCT), and donated duplicate samples of alveolar breath for analysis with gas chromatography mass spectrometry (GC MS). Monte Carlo analysis of breath chromatograms revealed a mass ion as a biomarker that identified biopsy-proven lung cancer as well as suspicious pulmonary nodules on LDCT. The biomarker was termed Mass Abnormalities in Gaseous Ions with Imaging Correlates (MAGIIC). The chemical structure of MAGIIC was tentatively identified from the NIST library of mass spectra; the best-fit compounds included C4 and C5 alkane derivatives that were consistent with metabolic products of oxidative stress. Blinded validation of MAGIIC: the abundance of the MAGIIC biomarker was determined in a different group of 161 subjects undergoing screening with LDCT. They donated duplicate alveolar breath VOC samples that were analyzed at two independent laboratories. The study was blinded and monitored with Good Clinical Practice. The abundance of MAGIIC in breath predicted biopsy-proven lung cancer with 84% accuracy, sensitivity = 75.4% and specificity = 85.0%. MAGIIC also predicted pulmonary nodules in LDCT with 80.5% accuracy, sensitivity = 80.1% and specificity = 75.0%. Breath MAGIIC abundance was not significantly affected by tobacco smoking history.

CONCLUSIONS

in a blinded study, breath VOC MAGIIC accurately predicted lung cancer confirmed on a tissue biopsy, as well as suspicious pulmonary nodules observed on LDCT. MAGIIC may have been a product of oxidative stress and it could potentially be employed as an ancillary to LDCT to predict the likelihood that a pulmonary nodule is malignant.

The potential of breath analysis to improve outcome for patients with lung cancer

Lung cancer remains the most common cause of cancer related death in both the UK and USA. Development of diagnostic approaches that have the ability to detect lung cancer early are a research priority with potential to improve survival. Analysis of exhaled breath metabolites, or volatile organic compounds (VOCs) is an area of considerable interest as it could fulfil such requirements. Numerous studies have shown that VOC profiles are different in the breath of patients with lung cancer compared to healthy individuals or those with non-malignant lung diseases. This review provides a scientific and clinical assessment of the potential value of a breath test in lung cancer. It discusses the current understanding of metabolic pathways that contribute to exhaled VOC production in lung cancer and reviews the research conducted to date. Finally, we highlight important areas for future research and discuss how a breath test could be incorporated into various clinical pathways.

Ligand-Capped Ultrapure Metal Nanoparticle Sensors for the Detection of Cutaneous Leishmaniasis Disease in Exhaled Breath

Human cutaneous leishmaniasis, although designated as one of the most neglected tropical diseases, remains underestimated due to its misdiagnosis. The diagnosis is mainly based on the microscopic detection of amastigote forms, isolation of the parasite, or the detection of Leishmania DNA, in addition to its differential clinical characterization; these tools are not always available in routine daily practice, and they are expensive and time-consuming. Here, we present a simple-to-use, noninvasive approach for human cutaneous leishmaniasis diagnosis, which is based on the analysis of volatile organic compounds in exhaled breath with an array of specifically designed chemical gas sensors. The study was realized on a group of n = 28 volunteers diagnosed with human cutaneous leishmaniasis and a group of n = 32 healthy controls, recruited in various sites from Tunisia, an endemic country of the disease. The classification success rate of human cutaneous leishmaniasis patients achieved by our sensors test was 98.2% accuracy, 96.4% sensitivity, and 100% specificity. Remarkably, one of the sensors, based on CuNPs functionalized with 2-mercaptobenzoxazole, yielded 100% accuracy, 100% sensitivity, and 100% specificity for human cutaneous leishmaniasis discrimination. While AuNPs have been the most extensively used in metal nanoparticle-ligand sensing films for breath sensing, our results demonstrate that chemical sensors based on ligand-capped CuNPs also hold great potential for breath volatile organic compounds detection. Additionally, the chemical analysis of the breath samples with gas chromatography coupled to mass spectrometry identified nine putative breath biomarkers for human cutaneous leishmaniasis.

Endogenous volatile organic compounds in acute myeloid leukemia: origins and potential clinical applications

Not unlike many cancer types, acute myeloid leukemia (AML) exhibits many metabolic changes and reprogramming, causing changes in lipid metabolism. Some of the distinct molecular abnormalities associated with AML also modify the metabolic changes. Both processes result in changes in the production of endogenous volatile organic compounds (VOCs). The increasing availability of highly sensitive methods for detecting trace chemicals provides the opportunity to investigate the role of patient-specific VOC finger-prints as biomarkers for detecting early relapse or minimal residual disease in AML. Since VOC production is reliant on metabolic activities, when combined with currently available methods, VOC analysis may identify within a group of patients with flow cytometric or molecular evidence of residual disease those most at risk for disease relapse.

Development of breath test for pneumoconiosis: a case-control study

Background

Lipid peroxidation plays an important role in the pathogenesis of pneumoconiosis. Volatile organic compounds (VOCs) generated from lipid peroxidation might be used to detect pneumoconiosis. The objective of this study was to develop a breath test for pneumoconiosis.

Methods

A case-control study was designed. Breath and ambient air were analysed by gas chromatography/mass spectrometry. After blank correction to prevent contamination from ambient air, we used canonical discriminant analysis (CDA) to assess the discrimination accuracy and principal component analysis (PCA) to generate a prediction score. The prediction accuracy was calculated and validated using the International Classification of Radiographs of the Pneumoconiosis criteria combined with an abnormal pulmonary function test as a reference standard. We generated a receiver operator characteristic (ROC) curve and calculated the area under the ROC curve (AUC) to estimate the screening accuracy of the breath test.

Results

We enrolled 200 stone workers. After excluding 5 subjects with asthma and 16 subjects who took steroids or nonsteroidal anti-inflammatory drugs, a total of 179 subjects were used in the final analyses, which included 25 cases and 154 controls. By CDA, 88.8% of subjects were correctly discriminated by their exposure status and the presence of pneumoconiosis. After excluding the VOCs of automobile exhaust and cigarette smoking, pentane and C5-C7 methylated alkanes constituted the major VOCs in the breath of persons with pneumoconiosis. Using the prediction score generated from PCA, the ROC-AUC was 0.88 (95% CI = 0.80—0.95), and the mean ROC-AUC of 5-fold cross-validation was 0.90. The breath test had good accuracy for pneumoconiosis diagnosis.

Conclusion

The analysis of breath VOCs has potential in the screening of pneumoconiosis for its non-invasiveness and high accuracy. We suggest that a multi-centre study is warranted and that all procedures must be standardized before clinical application.

Breath Alkane as an index of severity for oral submucous fibrosis: A new perspective?

Oral submucous fibrosis (OSMF) is a devastating disease commonly seen in the Asian subcontinent that results in significant functional morbidity for patients and has a high potential for malignant transformation. Over the last three decades, different diagnostic methods have been described to quantify and grade OSMF severity. Some methods have been used with perceived favorable outcomes although recurrence and malignant transformation remains a problem in many cases, and OSMF presents a major therapeutic challenge. We present a simple, noninvasive and less time-consuming diagnostic method which measures the severity of OSMF, helping to predict its malignant transformation and monitoring the effect of medical therapy on this disease.

Significance of Exhaled Breath Test in Clinical Diagnosis: A Special Focus on the Detection of Diabetes Mellitus

Analysis of volatile organic compounds (VOCs) emanating from human exhaled breath can provide deep insight into the status of various biochemical processes in the human body. VOCs can serve as potential biomarkers of physiological and pathophysiological conditions related to several diseases. Breath VOC analysis, a noninvasive and quick biomonitoring approach, also has potential for the early detection and progress monitoring of several diseases. This paper gives an overview of the major VOCs present in human exhaled breath, possible biochemical pathways of breath VOC generation, diagnostic importance of their analysis, and analytical techniques used in the breath test. Breath analysis relating to diabetes mellitus and its characteristic breath biomarkers is focused on. Finally, some challenges and limitations of the breath test are discussed.

Using a chemiresistor-based alkane sensor to distinguish exhaled breaths of lung cancer patients from subjects with no lung cancer

BACKGROUND

Breath alkanes are reported to be able to discriminate lung cancer patients from healthy people. A simple chemiresistor-based sensor was designed to respond to alkanes by a change in resistance measured by a digital multimeter connected to the sensor. In preclinical experiments, the sensor response was found to have a strong positive linear relationship with alkane compounds and not responsive to water. This study aimed to determine the ability of the alkane sensor to distinguish the exhaled breaths of lung cancer patients from that of chronic obstructive pulmonary disease (COPD) patients and control subjects without lung cancer.

METHODS

In this cross-sectional study, 12 treatment-naive patients with lung cancer, 12 ex- or current smokers with COPD and 13 never-smokers without lung disease were asked to exhale through a drinking straw into a prototype breath-in apparatus made from an empty 125 mL Vitagen^® bottle with the chemiresistor sensor attached at its inside bottom to measure the sensor peak output (percentage change of baseline resistance measured before exhalation to peak resistance) and the time taken for the baseline resistance to reach peak resistance.

RESULTS

Analysis of multivariate variance and post-hoc Tukey test revealed that the peak output and the time to peak values for the lung cancer patients were statistically different from that for both the COPD patients and the controls without lung disease, Pillai's Trace =0.393, F=3.909, df = (4, 64), P=0.007. A 2.20% sensor peak output and a 90-s time to peak gave 83.3% sensitivity and 88% specificity in diagnosing lung cancer. Tobacco smoking did not affect the diagnostic accuracy of the sensor.

CONCLUSIONS

The alkane sensor could discriminate patients with lung cancer from COPD patients and people without lung disease. Its potential utility as a simple, cheap and non-invasive test for early lung cancer detection needs further studies.

Frequent sampling allows detection of short and rapid surges of exhaled ethane during cardiac surgery

During cardiopulmonary bypass (CPB), hypoperfusion and reperfusion may cause oxidative stress and lipid peroxidation that generates ethane. The aim of this pilot study was to assess the feasibility of frequent sampling of exhaled ethane during cardiac surgery. After approval of the Research Ethics Committee, 10 patients undergoing combined aortic valve and coronary artery bypass surgery were enrolled. Breath samples were drawn in the perioperative period and analyzed by a rapid, sensitive and validated gas-chromatographic method. Increased exhaled ethane was regularly seen following sternotomy, after the start of CPB and after aortic clamp removal, whereas no change was seen after termination of bypass. In one patient, the maximum increase in exhaled ethane was 30-fold. Peak durations lasted only 2–4 min. This study demonstrates that frequent sampling of breath ethane is feasible in a clinical setting, allowing detection of rapid ethane surges of short duration.

Oxidative Stress and DNA Damage: Implications in Inflammatory Bowel Disease

This review will focus on published human studies on oxidative stress and DNA damage in inflammatory bowel disease (IBD), both ulcerative colitis and Crohn's disease, assessing their role in the pathophysiology of these diseases. Search was performed over PubMed and ScienceDirect databases to identify relevant bibliography, using keywords including "oxidative stress," "DNA damage," "IBD," and "oxidative DNA damage." Whether as cause or effect, mechanisms underlying oxidative stress have the potential to condition the course of various pathologies, particularly those driven by inflammatory scenarios. IBDs are chronic inflammatory relapsing conditions. Oxidative stress has been associated with some of the characteristic clinical features exhibited in IBD, namely tissue injury and fibrosis, and also to the ulcerative colitis-associated colorectal cancer. The possible influence of oxidative stress over therapeutic behavior and response, as well as their contribution to the oxidative burden and consequences, is also addressed. Due to the high prevalence and incidence of IBD worldwide, and also to its associated morbidity, complications, and disease and treatment costs, it is of paramount importance to better understand the pathophysiology of these diseases.

Breathomics in lung disease

Volatile organic compounds (VOCs) are produced by virtually all metabolic processes of the body. As such, they have potential to serve as noninvasive metabolic biomarkers. Since exhaled VOCs are either derived from the respiratory tract itself or have passed the lungs from the circulation, they are candidate biomarkers in the diagnosis and monitoring of pulmonary diseases in particular. Good examples of the possibilities of exhaled volatiles in pulmonary medicine are provided by the potential use of VOCs to discriminate between patients with lung cancer and healthy control subjects and to noninvasively diagnose infectious diseases and the association between VOCs and markers of disease activity that has been established in obstructive lung diseases. Several steps are, however, required prior to implementation of breath-based diagnostics in daily clinical practice. First, VOCs should be studied in the intention-to-diagnose population, because biomarkers are likely to be affected by multiple (comorbid) conditions. Second, breath collection and analysis procedures need to be standardized to allow pooling of data. Finally, apart from probabilistic analysis for diagnostic purposes, detailed examination of the nature of volatile biomarkers not only will improve our understanding of the pathophysiologic origins of these markers and the nature of potential confounders but also can enable the development of sensors that exhibit maximum sensitivity and specificity toward specific applications. By adhering to such an approach, exhaled biomarkers can be validated in the diagnosis, monitoring, and treatment of patients in pulmonary medicine and contribute to the development of personalized medicine.

Breath analysis as a potential and non-invasive frontier in disease diagnosis: an overview

Currently, a small number of diseases, particularly cardiovascular (CVDs), oncologic (ODs), neurodegenerative (NDDs), chronic respiratory diseases, as well as diabetes, form a severe burden to most of the countries worldwide. Hence, there is an urgent need for development of efficient diagnostic tools, particularly those enabling reliable detection of diseases, at their early stages, preferably using non-invasive approaches. Breath analysis is a non-invasive approach relying only on the characterisation of volatile composition of the exhaled breath (EB) that in turn reflects the volatile composition of the bloodstream and airways and therefore the status and condition of the whole organism metabolism. Advanced sampling procedures (solid-phase and needle traps microextraction) coupled with modern analytical technologies (proton transfer reaction mass spectrometry, selected ion flow tube mass spectrometry, ion mobility spectrometry, e-noses, etc.) allow the characterisation of EB composition to an unprecedented level. However, a key challenge in EB analysis is the proper statistical analysis and interpretation of the large and heterogeneous datasets obtained from EB research. There is no standard statistical framework/protocol yet available in literature that can be used for EB data analysis towards discovery of biomarkers for use in a typical clinical setup. Nevertheless, EB analysis has immense potential towards development of biomarkers for the early disease diagnosis of diseases.

Umbelliferone β-d-galactopyranoside exerts an anti-inflammatory effect by attenuating COX-1 and COX-2

Umbelliferone β-d-galactopyranoside (UFG) is a coumarin found in many plants. This study examines the anti-inflammatory potential of UFG on chronic inflammation induced by Complete Freund Adjuvant (CFA) in experimental rats.

Quantitative analysis of volatile organic compounds released and consumed by rat L6 skeletal muscle cells in vitro

Knowledge of the release of volatile organic compounds (VOCs) by cells provides important information on the origin of VOCs in exhaled breath. Muscle cells are particularly important, since their release of volatiles during the exertion of an effort contributes considerably to breath concentration profiles. Presently, the cultivation of human skeletal muscle cells is encountering a number of obstacles, necessitating the use of animal muscle cells in in vitro studies. Rat L6 skeletal muscle cells are therefore commonly used as a model for studying the molecular mechanisms of human skeletal muscle differentiation and functions, and facilitate the study of the origin and metabolic fate of the endogenously produced compounds observed in breath and skin emanations. Within this study the production and uptake of VOCs by rat L6 skeletal muscle cells were investigated using gas chromatography with mass spectrometric detection, combined with head-space needle trap extraction as the pre-concentration technique (HS-NTE-GC-MS). Seven compounds were found to be produced, whereas sixteen species were consumed (Wilcoxon signed-rank test, p < 0.05) by the cells being studied. The set of released volatiles included two ketones (2-pentanone and 2-nonanone), two volatile sulphur compounds (dimethyl sulfide and methyl 5-methyl-2-furyl sulphide), and three hydrocarbons (2-methyl 1-propene, n-pentane and isoprene). Of the metabolized species there were thirteen aldehydes (2-propenal, 2-methyl 2-propenal, 2-methyl propanal, 2-butenal, 2-methyl butanal, 3-methyl butanal, n-pentanal, 2-methyl 2-butenal, n-hexanal, benzaldehyde, n-octanal, n-nonanal and n-decanal), two esters (n-propyl propionate and n-butyl acetate), and one volatile sulphur compound (dimethyl disulfide). The possible metabolic pathways leading to the uptake and release of these compounds by L6 cells are proposed and discussed. An analysis of the VOCs showed them to have huge potential for the identification and monitoring of some molecular mechanism and conditions.

Faecal gas analysis by electronic nose as novel, non-invasive method for assessment of active and quiescent paediatric inflammatory bowel disease: Proof of principle study

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) and its two phenotypes ulcerative colitis (UC) and Crohn's disease (CD) are essentially assessed by endoscopy, both in initial diagnostic work-up and during follow-up. This carries a high burden, especially on paediatric patients. Faecal volatile organic compounds (VOCs) are considered potential non-invasive biomarkers for intestinal diseases linked to gut microbiota alterations. We hypothesized that faecal VOC analysis by electronic nose allows discrimination of children with CD, UC and controls during active disease and remission.

METHODS

Faecal VOC patterns of children with newly diagnosed IBD and controls were studied by an electronic nose (Cyranose 320®), at baseline and upon achieving remission at 6-weeks of follow-up. Disease activity was assessed by global physician's assessment, substantiated by serum C-reactive protein and faecal calprotectin. Internally cross-validated receiver-operator-characteristic curves and corresponding sensitivity and specificity for detection of IBD were calculated RESULTS: Faecal VOC profiles of patients with UC (26) and CD (29) differed from controls (28); in active disease (AUC±95% CI, p-value, sensitivity, specificity: 1.00±0.00; p<0.001, 100%, 100%) and (0.85±0.05, p<0.001, 86%, 67%) and in clinical remission (0.94±0.06, p<0.001, 94%, 94%) and (0.94±0.06, p<0.001, 94%, 94%), respectively. Furthermore, CD-patients differed from UC-patients during active disease (0.96±0.03; p<0.001, 97%, 92%), and upon achieving clinical remission (0.81±0.08, p=0.002, 88%, 72%).

CONCLUSION

Faecal VOC analysis allowed discrimination of paediatric patients with IBD from controls, both during active disease and remission. It therefore has potential as non-invasive test, in both diagnostic work-up and assessment of disease activity in IBD.

Characterization of the biochemical effects of naphthalene on the mouse respiratory system using NMR-based metabolomics

Naphthalene is a ubiquitous environmental pollutant to which humans are exposed. Previous studies have demonstrated that naphthalene causes bronchiolar epithelial necrosis in the mouse distal airway, after parenteral administration. In this study, metabolic variations in the bronchoalveolar lavage fluid (BALF) and the lung tissues of naphthalene-treated mice and controls were examined using nuclear magnetic resonance (NMR)-based metabolomics to identify the toxic mechanism. Male ICR mice were treated with naphthalene [0, 50, 100 and 200 mg kg(-1), intraperitoneally (i.p.)]. After 24 h, BALF and lung tissues were collected and prepared for (1)H and J-resolved (JRES) NMR analysis after principal component analysis (PCA). PCA modeling of p-JRES spectra from the BALF, as well as hydrophilic and hydrophobic lung metabolites, enabled the high-dose group to be discriminated from the control group; increased levels of isopropanol, ethane, and acetone and lower levels of ethanol, acetate, formate, and glycerophosphocholine were detected in the BALF of mice treated with higher doses of naphthalene. Furthermore, increased isopropanol and phosphorylcholine-containing lipid levels and decreased succinate and glutamine levels were discovered in the lungs of naphthalene-exposed mice. These metabolic changes may be related to lipid peroxidation, disruptions of membrane components and imbalanced energy supply, and these results may partially explain the loss of cell membrane integrity in the airway epithelial cells of naphthalene-treated mice. We conclude that NMR-based metabolomic studies on BALF and lung tissues are a powerful tool to understand the mechanisms underlying respiratory toxicity.

Clinical application of volatile organic compound analysis for detecting infectious diseases

This review article introduces the significance of testing of volatile organic compounds (VOCs) in clinical samples and summarizes important features of some of the technologies. Compared to other human diseases such as cancer, studies on VOC analysis in cases of infectious diseases are limited. Here, we have described results of studies which have used some of the appropriate technologies to evaluate VOC biomarkers and biomarker profiles associated with infections. The publications reviewed include important infections of the respiratory tract, gastrointestinal tract, urinary tract, and nasal cavity. The results highlight the use of VOC biomarker profiles resulting from certain infectious diseases in discriminating between infected and healthy subjects. Infection-related VOC profiles measured in exhaled breath as well as from headspaces of feces or urine samples are a source of information with respect to disease detection. The volatiles emitted in clinical matrices may on the one hand represent metabolites of the infecting pathogen or on the other hand reflect pathogen-induced host responses or, indeed, a combination of both. Because exhaled-breath samples are easy to collect and online instruments are commercially available, VOC analysis in exhaled breath appears to be a promising tool for noninvasive detection and monitoring of infectious diseases.

Effects of dietary nutrients on volatile breath metabolites

Breath analysis is becoming increasingly established as a means of assessing metabolic, biochemical and physiological function in health and disease. The methods available for these analyses exploit a variety of complex physicochemical principles, but are becoming more easily utilised in the clinical setting. Whilst some of the factors accounting for the biological variation in breath metabolite concentrations have been clarified, there has been relatively little work on the dietary factors that may influence them. In applying breath analysis to the clinical setting, it will be important to consider how these factors may affect the interpretation of endogenous breath composition. Diet may have complex effects on the generation of breath compounds. These effects may either be due to a direct impact on metabolism, or because they alter the gastrointestinal flora. Bacteria are a major source of compounds in breath, and their generation of H₂, hydrogen cyanide, aldehydes and alkanes may be an indicator of the health of their host.

Detection of an extended human volatome with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry

BACKGROUND

Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOF MS) has been proposed as a powerful new tool for multidimensional analysis of complex chemical mixtures. We investigated GCxGC-TOF MS as a new method for identifying volatile organic compounds (VOCs) in normal human breath.

METHODS

Samples of alveolar breath VOCs and ambient room air VOC were collected with a breath collection apparatus (BCA) onto separate sorbent traps from 34 normal healthy volunteers (mean age = 40 yr, SD = 17 yr, male/female = 19/15). VOCs were separated on two serial capillary columns separated by a cryogenic modulator, and detected with TOF MS. The first and second dimension columns were non-polar and polar respectively.

RESULTS

BCA collection combined with GC×GC-TOF MS analysis identified approximately 2000 different VOCs in samples of human breath, many of which have not been previously reported. The 50 VOCs with the highest alveolar gradients (abundance in breath minus abundance in ambient room air) mostly comprised benzene derivatives, acetone, methylated derivatives of alkanes, and isoprene.

CONCLUSIONS

Collection and analysis of breath VOCs with the BCA-GC×GC-TOF MS system extended the size of the detectable human volatile metabolome, the volatome, by an order of magnitude compared to previous reports employing one-dimensional GC-MS. The size of the human volatome has been under-estimated in the past due to coelution of VOCs in one-dimensional GC analytical systems.

Volatile breath biomarkers for patient monitoring during haemodialysis

Patients with end-stage renal disease (ESRD) are at risk for a numerous complications. This study was intended to evaluate breath analysis for monitoring and therapy initiation under haemodialysis (HD). Exhaled alveolar air from 30 ESRD patients during 4 h thrice-weekly HD was analysed by means of HS-SPME-GC-MS. Venous blood samples were taken for determination of conventional serum parameters. Exhaled concentrations of isoprene (10-589 ppbV) were dropped at initiation of HD and increased at the end of HD. Isoprene concentration changes were similar to changes of serum LDH activities. Variation of exhaled acetone concentrations (59 to 8509 ppbV) was significantly lower in diabetic patients when compared to non-diabetics. Exhaled pentane (0.3 to 12 ppbV) increased at onset of HD and returned to baseline levels afterwards. Benzene concentrations showed typical washout characteristics. Ethanol and DMS concentrations remained constant during HD. Breath analysis can be used to recognize oxidative stress, metabolic conditions and haemolysis during HD. Hence, non-invasive breath testing could be used to monitor ESRD patients under HD and prevent them from being affected by well-known detrimental side effects of renal replacement therapy.

Allergic asthma exhaled breath metabolome: a challenge for comprehensive two-dimensional gas chromatography

Allergic asthma represents an important public health issue, most common in the paediatric population, characterized by airway inflammation that may lead to changes in volatiles secreted via the lungs. Thus, exhaled breath has potential to be a matrix with relevant metabolomic information to characterize this disease. Progress in biochemistry, health sciences and related areas depends on instrumental advances, and a high throughput and sensitive equipment such as comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GC×GC-ToFMS) was considered. GC×GC-ToFMS application in the analysis of the exhaled breath of 32 children with allergic asthma, from which 10 had also allergic rhinitis, and 27 control children allowed the identification of several hundreds of compounds belonging to different chemical families. Multivariate analysis, using Partial Least Squares-Discriminant Analysis in tandem with Monte Carlo Cross Validation was performed to assess the predictive power and to help the interpretation of recovered compounds possibly linked to oxidative stress, inflammation processes or other cellular processes that may characterize asthma. The results suggest that the model is robust, considering the high classification rate, sensitivity, and specificity. A pattern of six compounds belonging to the alkanes characterized the asthmatic population: nonane, 2,2,4,6,6-pentamethylheptane, decane, 3,6-dimethyldecane, dodecane, and tetradecane. To explore future clinical applications, and considering the future role of molecular-based methodologies, a compound set was established to rapid access of information from exhaled breath, reducing the time of data processing, and thus, becoming more expedite method for the clinical purposes.

Analysis of volatile organic compounds released from human lung cancer cells and from the urine of tumor-bearing mice

Backgrounds

A potential strategy for the diagnosis of lung cancer is to exploit the distinct metabolic signature of this disease by way of biomarkers found in different sample types. In this study, we investigated whether specific volatile organic compounds (VOCs) could be detected in the culture medium of the lung cancer cell line A549 in addition to the urine of mice implanted with A549 cells.

Results

Several VOCs were found at significantly increased or decreased concentrations in the headspace of the A549 cell culture medium as compared with the culture medium of two normal lung cell lines. We also analyzed the urine of mice implanted with A549 cells and several VOCs were also found to be significantly increased or decreased relative to urine obtained from control mice. It was also revealed that seven VOCs were found at increased concentrations in both sample types. These compounds were found to be dimethyl succinate, 2-pentanone, phenol, 2-methylpyrazine, 2-hexanone, 2-butanone and acetophenone.

Conclusions

Both sample types produce distinct biomarker profiles, and VOCs have potential to distinguish between true- and false-positive screens for lung cancer.

The analgesic and anti-rheumatic effects of Thladiantha dubia fruit crude polysaccharide fraction in mice and rats

ETHNOPHARMACOLOGICAL RELEVANCE

The fruit of Thladiantha dubia has been used in Chinese manchu nationality folk medicine for treatment of various pains, such as rheumatic pain, lumbocrural pain, and dysmenorrhea. The aim of the present study was to evaluate the anti-rheumatic effect of Thladiantha dubia fruit crude polysaccharide (TF-P) fraction in rats.

MATERIALS AND METHODS

TF-P was evaluated in mice for analgesic activity using acetic acid-induced abdominal contractions test and for anti-inflammatory activity using xylene-induced ear oedema model. Moreover, rheumatoid arthritis (RA) was induced by injection of CFA into the subplantar surface of the hind paw of the male Wistar rats. Joint swelling was measured. In order to evaluate the effect of TF-P on disease progression, proinflammatory mediators (TNF-α and IL-2), and antioxidant indicators (SOD, MDA, and NO) were determined in rats induced by CFA. Pathologic changes of RA in rats were also observed under light microscope.

RESULTS AND CONCLUSIONS

In the present study, TF-P at the dose of 200mg/kg (according to the clinical traditional dosage) significantly reduced writhings and stretchings induced by the acetic acid in mice. TF-P significantly inhibited xylene-induced ear oedema in mice, compared with control group. TF-P significantly inhibited inoculated and non-inoculated joint swellings in rats induced by CFA. TF-P had no effect of body weight in rats. The histopathological analysis suggested that TF-P obviously alleviated the degree of RA rats. TF-P treated rats preserved a nearly normal histological architecture of the joint. Results of the present study confirm the use of Thladiantha dubia traditionally for the treatment of painful and inflammatory conditions. Those results suggest TF-P has protective and therapeutic effects on RA rats induced by CFA.

The possibilities will take your breath away: breath analysis for assessing environmental exposure

Human breath is the gaseous exchange with the blood and thus contains trace organic contaminants and metabolites representative of environmental doses. Sampling and analysis of gaseous components in human breath offers a noninvasive and quick means of qualitatively and quantitatively assessing internalized doses of environmental contaminants. Although the humid and complex nature of breath is a challenge for detection of part-per-trillion to part-per-billion concentrations of environmental contaminants, recent advances in chemical analysis and instrumentation are allowing determination of environmental exposure and disease detection.

A whey-based glutathione-enhancing diet decreases allergen-induced airway contraction in a guinea-pig model of asthma

Since an allergen-induced early asthmatic reaction is likely to be accompanied by oxidative stress and since levels of the endogenous antioxidant glutathione can be enhanced by a whey-based diet (undenatured whey protein concentrate, UWPC), it was investigated whether UWPC could alleviate allergen-induced lung contractions. Guinea pigs were fed water or UWPC twice a day starting at day - 3 up to day 20. The animals were sensitised to ovalbumin or received saline on day 0. Serum samples were taken at several days after sensitisation to measure allergen-specific IgG. On day 20, lungs were isolated and perfused with buffer containing the allergen ovalbumin. Airway contractions were assessed, and mediators and indicators for oxidative stress were measured in the lung effluent. Moreover, glutathione levels were determined in the liver. The indicator of oxidative stress and airway contractile mediator, 8-iso-PGF(2α), was increased upon ovalbumin challenge in ovalbumin-sensitised groups. Furthermore, thiobarbituric acid-reactive substances (TBARS) were increased as well. Sensitisation with ovalbumin increased IgG levels from day 12 up to day 20, which were not influenced by the UWPC diet. In contrast, the UWPC diet significantly enhanced glutathione levels in the liver. Moreover, the UWPC diet significantly reduced the ovalbumin-induced anaphylactic response by 45 % and decreased PGE2 levels by 55 % in the effluent fluid. We show for the first time that during anaphylaxis, there is acute oxidative stress in the respiratory tract. The UWPC diet did not influence the sensitisation response to the allergen but did increase endogenous glutathione levels. The UWPC diet profoundly reduces allergen-induced airway constrictions, which opens new avenues for dietary management of allergic diseases.