The changes of superoxide dismutase, catalase and glutathione peroxidase activities in erythrocytes of active and passive smokers

Differential effects of environmental exposures on clinically relevant endophenotypes between sexes

Sex and gender differences play a crucial role in health and disease outcomes. This study used data from the National Health and Nutrition Examination Survey to explore how environmental exposures affect health-related traits differently in males and females. We utilized a sex-stratified phenomic environment-wide association study (PheEWAS), which allowed the identification of associations across a wide range of phenotypes and environmental exposures. We examined associations between 272 environmental exposures, including smoking-related exposures such as cotinine levels and smoking habits, and 58 clinically relevant blood phenotypes, such as serum albumin and homocysteine levels. Our analysis identified 119 sex-specific associations. For example, smoking-related exposures had a stronger impact on increasing homocysteine, hemoglobin, and hematocrit levels in females while reducing serum albumin and bilirubin levels and increasing c-reactive protein levels more significantly in males. These findings suggest mechanisms by which smoking exposure may pose higher cardiovascular risks and greater induced hypoxia for women, and greater inflammatory and immune responses in men. The results highlight the importance of considering sex differences in biomedical research. Understanding these differences can help develop more personalized and effective health interventions and improve clinical outcomes for both men and women.

Analysis of cantharidin-induced kidney injury and the protective mechanism of resveratrol in mice determined by liquid chromatography/mass spectrometry-based metabonomics

Cantharidin (CTD) is the main active component in the traditional Chinese medicine Mylabris and an effective anti-tumor agent. However, it is relatively toxic and exhibits nephrotoxicity, which limits its clinical use. However, its toxic mechanism is not clear. The toxic effects of CTD exposure on the kidney and the protective effect of resveratrol (RES) were studied in a mouse model, by determination of serum biochemical and renal antioxidant indicators, histopathological and ultrastructural observation, and metabonomics. After CTD exposure, serum uric acid, creatinine, and tissue oxidative stress indicators increased, and the renal glomerular and tubular epithelial cells showed clear pathological damage. Ultrastructure observation revealed marked mitochondrial swelling, endoplasmic reticulum dilation, and the presence of autophagy lysosomes in glomerular epithelial cells. RES ameliorated the renal injury induced by CTD. Metabonomics analysis indicated that CTD can induce apoptosis and oxidative damage in kidney cells, mainly by disrupting sphingolipid and glutathione metabolism, increasing sphingosine and sphingomyelin levels, and decreasing glutathione levels. RES counteracts these effects by regulating renal cell proliferation, the inflammatory response, oxidative stress, and apoptosis, by improving the levels of phosphatidylcholine (PC), LysoPC, and lysophosphatidyl glycerol in the glycerophospholipid metabolism pathway, thereby reducing CTD-induced nephrotoxicity. The mechanisms of CTD-induced renal injury and the protective effect of RES were revealed by metabonomics, providing a basis for evaluating clinical treatment regimens to reduce CTD-induced nephrotoxicity.

Serum heme oxygenase-1 as a prognostic biomarker in patients with acute exacerbation of interstitial lung disease

Serum heme oxygenase (HO)-1 level has been reported as a clinically reliable diagnostic biomarker for acute exacerbation of interstitial lung disease (ILD); however, its utility for predicting mortality among these patients is unclear. Serum HO-1 levels of patients newly diagnosed with acute exacerbation of ILD were measured at the time of initiating steroid pulse therapy. The relationship between serum HO-1 and various other serum biomarkers, change in HRCT findings, and disease prognosis at 12 weeks after diagnosis of acute exacerbation was evaluated in 51 patients, of whom 17 (33%) had idiopathic pulmonary fibrosis (IPF). Serum HO-1 was higher in patients with acute exacerbation of IPF than in patients with acute exacerbation of other ILDs. Serum HO-1 levels were higher in patients who died within these 12 weeks than in survivors. Among age, sex, comorbidities, IPF diagnosis, HRCT findings, and blood biomarkers, serum HO-1 was a primary predictor of 12-week mortality. In 41 patients who underwent repeat HRCT, serum HO-1 was higher in patients with honeycomb progression than in those without. Serum HO-1 measurement could be useful for evaluating disease mortality and morbidity of patients with acute exacerbation of ILDs.

Cigarette Smoke-Induced Reactive Oxygen Species Formation: A Concise Review

Smoking is recognized as a significant risk factor for numerous disorders, including cardiovascular diseases, respiratory conditions, and various forms of cancer. While the exact pathogenic mechanisms continue to be explored, the induction of oxidative stress via the production of excess reactive oxygen species (ROS) is widely accepted as a primary molecular event that predisposes individuals to these smoking-related ailments. This review focused on how cigarette smoke (CS) promotes ROS formation rather than the pathophysiological repercussions of ROS and oxidative stress. A comprehensive analysis of existing studies revealed the following key ways through which CS imposes ROS burden on biological systems: (1) ROS, as well as radicals, are intrinsically present in CS, (2) CS constituents generate ROS through chemical reactions with biomolecules, (3) CS stimulates cellular ROS sources to enhance production, and (4) CS disrupts the antioxidant system, aggravating the ROS generation and its functions. While the evidence supporting these mechanisms is chiefly based on in vitro and animal studies, the direct clinical relevance remains to be fully elucidated. Nevertheless, this understanding is fundamental for deciphering molecular events leading to oxidative stress and for developing intervention strategies to counter CS-induced oxidative stress.

Resistance training prevents damage to the mitochondrial function of the skeletal muscle of rats exposed to secondary cigarette smoke

AIM

To analyze the consumption of oxygen and to quantify the mitochondrial respiratory chain proteins (OXPHOS) in the gastrocnemius muscle of rats exposed to cigarette smoke and/or RT practitioners.

MAIN METHODS

Wistar rats were divided into groups: Control (C), Smoker (S), Exercise (E) and Exercise Smoker (ES). Groups F and ES were exposed to the smoke of 4 cigarettes for 30 min, 2× a day, 5× a week, for 16 weeks. Groups E and ES performed four climbs with progressive load, 1× per day, 5× per week, for 16 weeks. The gastrocnemius muscle was collected for analysis of OXPHOS content and oxygen consumption. Groups S (vs. C) and ES (vs. C and E) showed lower body weight gain when observing the evolution curve.

KEY FINDINGS

The S rats showed a reduction in the NDUFB8 proteins of complex 1, SDHB of complex 2, MTC01 of complex 4 and ATP5A of complex 5 (ATP Synthase) compared to Group C. Additionally, S rats also showed increased consumption of O2 in Basal, Leak, Complex I and I/II combined measures compared to the other groups, suggesting that the activity of the mitochondria of these animals increased in terms of coupling and uncoupling parameters.

SIGNIFICANCE

Our data suggest that exposure to cigarette smoke for 16 weeks is capable of causing impairment of mitochondrial function with reduced expression of respiratory chain proteins in skeletal muscle. However, the RT was effective in preventing impairment of mitochondrial function in the skeletal muscle of rats exposed to secondary cigarette smoke.

A glyphosate-based herbicide disrupted hematopoiesis and induced organ toxicities, ameliorated by vitamin B12 in a mouse model

Glyphosate-based herbicides (GBH) are widely used worldwide. Their negative impact on human health is a matter of debate by regulatory bodies and the public. The present study sought to determine the impact of a GBH on the vital organs; and the potential protective effects of vitamin B12 (cyanocobalamin) supplementation. Sixty white Swiss mice were randomly assigned to five treatment groups, each containing twelve mice. Group one represented the normal control; Group two mice were treated with 375 mg/kg of GBH for 56 days; Group three mice received 10 mg/kg of cyanocobalamin for 56 days; Group four mice were administered with 375 mg/kg of GBH and 10 mg/kg cyanocobalamin for 56 days and Group five received 10 mg/kg cyanocobalamin first for 7 days, then continued thereafter co-administered together with 375 mg/kg of GBH for 56 days). Oral administration of GBH induced severe anemia in mice, which was attenuated by cyanocobalamin. Moreover, GBH resulted in a very significant alteration of platelets, WBCs, and its sub-types. Once again, cyanocobalamin stabilized the levels of platelets and WBCs in the presence of GBH. GBH-induced elevation of triglycerides and HDL was nullified by the administration of cyanocobalamin. Further studies showed evidence for GBH-induced inflammation represented by an imbalance in serum levels of the TNF-α: IL-10 and IFN-γ ratios. The GBH severely depleted GSH levels in the liver. A GBH-induced rise in GSH in the kidney, lungs and brain was noted; and is an indicator of antioxidant capacity enhancement in response to a GBH-induced oxidant challenge. Moreover, cyanocobalamin supplementation abrogated GBH-induced oxidative stress as depicted by stabilized GSH levels in the liver, kidney, lungs, and brain. In the presence of cyanocobalamin, the GBH-induced liver injury depicted by elevation of AST, ALT, and bilirubin, was attenuated. From the results, we conclude that the capacity of cyanocobalamin to assuage GBH-induced inflammatory responses, hepatotoxicity, and hematological alteration as well as oxidative stress may be attributable to its antioxidant and anti-inflammatory properties. The current findings provide a solid foundation for further scrutiny of this phenomenon, with vital implications in GBH exposure and the role of potent antioxidant supplementation in the management of GBH-induced toxicity.

Glutathione Peroxidase Activity Is Altered in Vascular Cognitive Impairment-No Dementia and Is a Potential Marker for Verbal Memory Performance

Background:

Coronary artery disease (CAD) increases risk for vascular cognitive impairment-no dementia (VCIND), a precursor to dementia, potentially through persistent oxidative stress.

Objective:

This study assessed peripheral glutathione peroxidase activity (GPX), which is protective against oxidative stress, in VCIND versus cognitively normal CAD controls (CN). GPX activity was also evaluated as a biomarker of cognition, particularly verbal memory.

Methods:

120 CAD patients with VCIND (1SD below norms on executive function or verbal memory (VM)) or without (CN) participated in exercise rehabilitation for 24 weeks. Neurocognitive and cardiopulmonary fitness (VO_2peak) assessments and plasma were collected at baseline and 24-weeks.

Results:

GPX was higher in VCIND compared to CN (F_1,119 = 3.996, p = 0.048). Higher GPX was associated with poorer baseline VM (β= –0.182, p = 0.048), and longitudinally with VM decline controlling for sex, body mass index, VO_2peak, and education (b[SE] = –0.02[0.01], p = 0.004). Only CN participants showed improved VM performance with increased fitness (b[SE] = 1.30[0.15], p < 0.005).

Conclusion:

GPX was elevated in VCIND consistent with a compensatory response to persistent oxidative stress. Increased GPX predicted poorer cognitive outcomes (verbal memory) in VCIND patients despite improved fitness.

Serum catalase, thiol and myeloperoxidase levels in children passively exposed to cigarette smoke

Background

Free radicals found in cigarette smoke can harm all tissues and cellular structures in the human body. Passive smoking increases free radical production, leads to the depletion of antioxidants and increases oxidative stress which causes lipid peroxidation. Many studies have been conducted to determine the effects of passive smoking on antioxidant enzymes and lipid levels in adults, but pediatric studies on this topic are few. In our study, we compared the levels of antioxidants, oxidants, total and LDL cholesterol in children exposed to passive cigarette smoking with a healthy control group that was not exposed to passive smoking.

Methods

A total of 41 children (4–17 years of age, 24 girls and 17 boys) exposed to passive smoking and 18 healthy girls and 12 healthy boys were included in this study. Secondhand smoking was confirmed via measurement of the cotinine/creatinine ratio. Various sociodemographic characteristics of patients were recorded. The levels of catalase, thiol, myeloperoxidase were measured to determine the antioxidant and oxidant levels in children, while the levels of total cholesterol and LDL cholesterol were measured to determine the alterations in lipid profile.

Results

The groups were similar in regard to demographic characteristics. Myeloperoxidase levels were significantly higher in the passive cigarette smoking group compared to the non-exposure group; however, catalase and thiol levels were similar. In regard to lipid profile, the levels of total cholesterol and LDL cholesterol were also similar in those with and without exposure to passive smoking.

Conclusions

Our findings suggest that the effects of passive smoking initially influence oxidants (MPO), but not antioxidants (thiol and catalase). However, it is apparent that passive smoking adversely affects oxidative balance in children and this may lead to the development of various diseases which could cause significant morbidity and mortality.

How do glutathione antioxidant enzymes and total antioxidant status respond to air pollution exposure?

This study aims to investigate how antioxidant enzyme activity and overall antioxidant capacity respond to short-term changes in exposure to air pollution. 201 participants were recruited before- and followed up during- and after- the 2008 Beijing Olympics. Serum levels of antioxidant enzymes including glutathione S-transferases (GST), glutathione peroxidase (GPx), glutathione reductase (GR), and total antioxidant status (TAS) were measured. We used linear mixed-effects models to compare changes in antioxidant enzymes across the three periods after adjusting for potential confounding factors. Among all participants, glutathione peroxidase (GPx) levels decreased by 12.0% when air pollution dropped by 50-60% during the Olympics and increased by 6.5% when air pollution levels rose after the Olympics. The magnitude of increase among males, smokers, and older individuals was relatively smaller compared to females, nonsmokers, and younger individuals. Among all participants, total antioxidant status (TAS) significantly decreased by 6.23% during the games and continued to decrease by 4.41% after the games. However, among females, nonsmokers, and younger participants, there was an increase in TAS response to the elevated air pollution levels. Our study observed strong responses in GPx and TAS levels to the short-term decrease and increase of air pollution levels and responses varied among subgroups.

Effects of Tobacco on Salivary Antioxidative and Immunologic Systems

Background: Tobacco use is a harmful habit that causes adverse effects on oral health and plays a most important role in cancer development. Saliva is the first fluid that is exposed to tobacco and its antioxidant system plays an important role in anti-cancer potential; therefore, this study was designed to compare the antioxidant activity and immunologic system of saliva in tobacco users (smokers and smokeless tobacco users) and non-users. Materials and Methods: In this cross-sectional study, unstimulated saliva samples of 75 healthy individuals from three equal groups were investigated. Participants in group A had no periodontal disease and never smoked. Group B had no periodontal disease, never used smokeless tobacco, but had 3 years history of smoking at least 10 cigarettes daily. The twenty-five participants in group C had no periodontal disease and had 1 year history of chewing a 10-g tobacco packet daily. Activity of salivary superoxide dismutase (SOD), salivary glutathione peroxide, and salivary IgA concentration was evaluated. Data were analyzed using SPSS (version 18) and running Kruskal-Wallis test. Statistical significance was set at p<0.05. Results: There were significant differences in the activities of the two enzymes and salivary IgA levels among the three groups. Activity of glutathione peroxide was higher in smokeless tobacco users. (P<0.001) while that of superoxide dismutase was higher in non-tobacco users than users (P<0.001). Salivary IgA levels were higher among smokeless tobacco users (p=0.04). Conclusion: Based on the results of the present study, the use of tobacco products decreases the antioxidative activity of the saliva and increases salivary IgA levels at the same time.

Antioxidant responses following active and passive smoking of tobacco and electronic cigarettes

CONTEXT

It has been indicated that acute active and passive tobacco cigarette smoking may cause changes on redox status balance that may result in significant pathologies. However, no study has evaluated the effects of active and passive e-cigarette smoking on redox status of consumers.

OBJECTIVE

To examine the acute effects of active and passive e-cigarette and tobacco cigarette smoking on selected redox status markers.

METHODS

Using a randomized single-blind crossover design, 30 participants (15 smokers and 15 nonsmokers) were exposed to three different experimental conditions. Smokers underwent a control session, an active tobacco cigarette smoking session (smoked 2 cigarettes within 30-min) and an active e-cigarette smoking session (smoked a pre-determined number of puffs within 30-min using a liquid with 11 ng/ml nicotine). Similarly, nonsmokers underwent a control session, a passive tobacco cigarette smoking session (exposure of 1 h to 23 ± 1 ppm of CO in a 60 m(3) environmental chamber) and a passive e-cigarette smoking session (exposure of 1 h to air enriched with pre- determined number of puffs in a 60 m(3) environmental chamber). Total antioxidant capacity (TAC), catalase activity (CAT) and reduced glutathione (GSH) were assessed in participants' blood prior to, immediately after, and 1-h post-exposure.

RESULTS

TAC, CAT and GSH remained similar to baseline levels immediately after and 1-h-post exposure (p > 0.05) in all trials.

CONCLUSIONS

Tobacco and e-cigarette smoking exposure do not acutely alter the response of the antioxidant system, neither under active nor passive smoking conditions. Overall, there is not distinction between tobacco and e-cigarette active and passive smoking effects on specific redox status indices.

Exercise intervention as a protective modulator against metabolic disorders in cigarette smokers

[Purpose] assess the impact of exercise intensity on desire to smoke, serum cotinine, stress hormones, total antioxidant capacity, and oxidative free radicals as potential markers of cardiopulmonary metabolic disorders were measured.in cigarette smokers. [Subjects and Methods] The participants (150 randomly selected healthy men, aged 18–55 years) were classified into 4 smoking groups: control (non-smokers; N= 30); mild (N = 33); moderate (N = 42), and heavy (N = 45). The participants were assigned to either moderate (8 weeks) or short-term (20–45 min) exercise training. The desire to smoke, Mood and Physical Symptoms Scale, and Subjective Exercise Experiences Scale scores, cotinine, stress hormones (cortisol and testosterone), free radicals (malondialdehyde, nitric oxide), and total antioxidant capacity were evaluated. [Results] Significant increases in serum cotinine, cortisol, testosterone, nitric oxide, and malondialdehyde levels and a reduction in total antioxidant capacity activity were observed in all smoker groups; heavy smokers showed a higher change in metabolites. In all smoker groups, both short and moderate- intensity exercises significantly reduce cotinine, cortisol, testosterone, and malondialdehyde and increased nitric oxide levels and total antioxidant capacity activity; further, the desire to smoke, Mood and Physical Symptoms Scale, and Subjective Exercise Experiences Scale scores were reduced. This supports the ability of exercise to increase nitric oxide bioavailability, enhance of blood vessels function and ultimately decrease the incidence of cardiopulmonary disorders. [Conclusion] Exercise interventions with varying intensities may be used as nicotine replacement therapy or protective aids against smoking-related cardiopulmonary disorders.

Effect of Cigarette Smoke on Salivary Total Antioxidant Capacity

Background and aims. Cigarette smoke can induce oral cancer by its free radicals and oxidative damage. Salivary anti-oxidants system is believed to have an important role in defense mechanisms against oxidative stress. This study was compared total antioxidant capacity (TAoC) of saliva in smokers and nonsmokers. Materials and methods . In this cross-sectional study, 30 male smokers with mean age of 45.23 years and 30 nonsmokers with mean age of 45.30 years participated. Unstimulated whole saliva samples were collected in the morning in two groups by spitting method. TAoC of saliva was measured with the special kit in two groups at the same time. Statistical analysis was performed by covariance test. Results. The mean salivary TAoC in nonsmokers (0.741±0.123 U/ml) was higher than that in smokers (0.529±0.167 U/ml). This difference was statistically significant (P<0.001). Conclusion. Smoking can alter salivary antioxidant capacity.

Increased sensitivity of DNA damage response-deficient cells to stimulated microgravity-induced DNA lesions

Microgravity is a major stress factor that astronauts have to face in space. In the past, the effects of microgravity on genomic DNA damage were studied, and it seems that the effect on genomic DNA depends on cell types and the length of exposure time to microgravity or simulated microgravity (SMG). In this study we used mouse embryonic stem (MES) and mouse embryonic fibroblast (MEF) cells to assess the effects of SMG on DNA lesions. To acquire the insight into potential mechanisms by which cells resist and/or adapt to SMG, we also included Rad9-deleted MES and Mdc1-deleted MEF cells in addition to wild type cells in this study. We observed significant SMG-induced DNA double strand breaks (DSBs) in Rad9^-/- MES and Mdc1^-/- MEF cells but not in their corresponding wild type cells. A similar pattern of DNA single strand break or modifications was also observed in Rad9^-/- MES. As the exposure to SMG was prolonged, Rad9^-/- MES cells adapted to the SMG disturbance by reducing the induced DNA lesions. The induced DNA lesions in Rad9^-/- MES were due to SMG-induced reactive oxygen species (ROS). Interestingly, Mdc1^-/- MEF cells were only partially adapted to the SMG disturbance. That is, the induced DNA lesions were reduced over time, but did not return to the control level while ROS returned to a control level. In addition, ROS was only partially responsible for the induced DNA lesions in Mdc1^-/- MEF cells. Taken together, these data suggest that SMG is a weak genomic DNA stress and can aggravate genomic instability in cells with DNA damage response (DDR) defects.

Oxidative stress status in recently abstinent methamphetamine abusers

AIM

Methamphetamine (METH) administration is associated with excessive oxidative stress. It is not known whether the systemic oxidative stress indices would alter during early abstinence in METH abusers with positive urine testing for recent METH exposure.

METHODS

Sixty-four non-treatment-seeking METH abusers enrolled from a controlled environment and 60 healthy controls participated in the study. Fasting serum malondialdehyde (MDA) levels and anti-oxidant indices, including superoxide dismutase (SOD) and catalase (CAT) activity, and glutathione (GSH) levels, were measured at baseline and 2 weeks after the first measurement. We compared the differences of these oxidative stress indices between METH abusers and controls and examined the changes of the indices 2 weeks after baseline in the METH group.

RESULTS

At baseline, the recently abstinent METH abusers had significantly higher MDA levels, lower SOD activity, and higher CAT activity and GSH levels compared to healthy controls. CAT and GSH values were positively correlated with MDA but negatively correlated with SOD. These oxidative stress indices did not significantly correlate with age, smoking amount, Alcohol Use Disorder Identification Test scores, or METH use variables. After 2 more weeks of abstinence, the indices did not alter nor normalize.

CONCLUSION

Compared to controls, we found that METH abusers have persistently higher systemic oxidative stress throughout early abstinence. The compromised SOD as well as elevated CAT activity and GSH levels may act together as a compensatory mechanism to counteract excessive oxidative stress induced by METH. Whether the oxidative stress could improve after a longer period of abstinence needs to be examined in future studies.

Maternal smoking does not influence vitamin A and E concentrations in mature breastmilk

OBJECTIVES

The aim of this study was to analyze the effects of maternal smoking on the total antioxidant status (TAS) and the concentrations of vitamins A and E in human breastmilk.

METHODOLOGY

The study group (n=20) comprised postpartum women who declared smoking more than five cigarettes per day (confirmed by urinalysis of the cotinine concentration). The control group included 25 nonsmoking postpartum women. Breastmilk samples were collected between day 30 and day 32 after delivery. TAS was determined by Rice-Evans and Miller method, whereas the amount of vitamins A and E was measured by high-performance liquid chromatography.

RESULTS

No significant differences were observed between breastmilk samples from smoking and nonsmoking mothers in terms of TAS and vitamin A and E concentrations. Additionally, no significant correlations were found between urinary cotinine and TAS (R=0.35, p=0.144) or vitamin A (R=0.14, p=0.571) and vitamin E (R=0.31, p=0.228) concentrations in breastmilk samples from smoking mothers.

CONCLUSIONS

Maternal smoking is not reflected by decreased TAS and vitamin A and E concentrations in mature milk.

Oxidative status in the lungs associated with tobacco smoke exposure

BACKGROUND

Oxidative stress has a critical role in inflammatory responce against tobacco smoke (TS). Testing exhaled breath condensate (EBC) samples is one of the methods used for assessment of airway inflammation caused by TS. We aimed to investigate oxidative stress in the lungs associated with TS and to evaluate the effect of this stress with pulmonary function tests (PFTs).

METHODS

We included 69 subjects as three groups into the study (Group I; 26 smokers, Group II; 21 passive smokers, Group III; 22 non-smokers without TS exposure). Levels of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), nitrite/nitrate [index of nitric oxide (NO) production], vitamin C, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were measured in EBC samples collected using a condenser and PFTs were performed.

RESULTS

The levels of MDA, 8-OHdG, SOD and GSH-Px were higher in smokers. NO levels gradually increased from Group I to Group III. MDA levels were lower in Group III than Group II. The levels of vitamin C were similar in all groups. We determined negative correlation between 8-OHdG levels and forced expiratory volume in one second (FEV₁), and maximum mean expiratory flow (MMEF), and a positive correlation between SOD levels and FEV₁.

CONCLUSIONS

TS exposure affected the balance between oxidative stress and antioxidant capacity of lungs. Preventing environmental TS exposure might decrease oxidative damage. Increased levels of 8-OHdG and SOD levels could be assessed as an early sign of airway damage.

GPX1 Pro(198)Leu polymorphism, erythrocyte GPX activity, interaction with alcohol consumption and smoking, and risk of colorectal cancer

GPX1 encoding the enzyme glutathione peroxidase 1 (GPX1) and hOGG1 encoding the 8-oxoguanine glycosylase 1 (OGG1) may counteract oxidative stress and resulting DNA damage associated with lifestyle-related exposures. We examined whether the polymorphisms GPX1 Pro(198)Leu and OGG1 Ser(326)Cys or low erythrocyte GPX enzyme activity in pre-diagnostic blood samples are associated with colorectal cancer risk, and assessed possible interactions between the polymorphisms or enzyme activity and various lifestyle factors in relation to colorectal cancer risk. Additionally, we studied whether the GPX1 Pro(198)Leu polymorphism and several lifestyle factors predict GPX activity in erythrocytes. The present study was nested within the prospective "Diet, Cancer and Health" study of 57,053 Danes including 375 colorectal cancer cases and a comparison group of 779 individuals matched on gender. Biomaterial was sampled and information on lifestyle factors was obtained from questionnaires filled in at enrolment in 1993-1997. GPX1 Pro(198)Leu, hOGG1 Ser(326)Cys and erythrocyte GPX enzyme activity were not associated with risk of colorectal cancer. We observed a higher risk associated with alcohol consumption and smoking among homozygous GPX1(198)Leu carriers, with incidence rate ratios for colorectal cancer of 1.45 (95% CI: 1.17-1.81, P=0.02) per 10g alcohol intake per day and 2.56 (95% CI: 0.99-6.61, P=0.02) among ever smokers compared with never smokers at enrolment. Erythrocyte GPX activity was influenced by the GPX1 Pro(198)Leu genotype, gender, smoking intensity, and intake of fruits and vegetables. Our results indicate that lifestyle-related oxidative stress may be a risk factor for colorectal cancer among subjects with a lowered defence.

Oxidative stress in mouse plasma and lungs induced by cigarette smoke and lipopolysaccharide

Short-term exposure to cigarette smoke (CS) or lipopolysaccharide (LPS) leads to acute lung inflammation through oxidant-antioxidant imbalance. We studied the response in mice exposed to smoke or LPS during five consecutive days, as measured by superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, as well as lipid peroxidation and nitric oxide levels in bronchoalveolar lavage fluid (BALF), lung homogenates, and plasma. Control mice were exposed to ambient air. Exposure to CS or LPS led to a similar influx of alveolar macrophages and neutrophils into the BALF; however, hydroxyproline levels were increased only in the CS group (p<0.001); SOD activity was increased in the BALF (p<0.001) and lung homogenates (p<0.05) of the CS group but was decreased in the BALF (p<0.05), lung homogenates (p<0.05) and plasma (p<0.01) of the LPS group. CAT activity was increased in the BALF (p<0.01), lung homogenates (p<0.001) and plasma (p<0.05) of the CS group but decreased in the BALF (p<0.001) and plasma (p<0.05) of the LPS group. GPx activity was reduced in the BALF (p<0.01) and plasma (p<0.01) of both the CS and LPS groups. Lipid peroxidation was increased in the BALF (p<0.001) and lung homogenates (p<0.001) of the CS group. Finally, the levels of nitrite were reduced in the CS (p<0.01) and LPS (p<0.001) groups. Our data show that the activity profiles of enzymes contributing to oxidant-antioxidant imbalance in the lungs differ depending on the inflammatory stimulus, and that SOD, CAT and GPx may be useful markers of oxidative stress in acute lung inflammation induced by exposure to CS.

Gene polymorphisms of oxidative stress enzymes: prediction of elderly renutrition

BACKGROUND

The free radical theory of aging suggests that damage caused by oxidative stress leads to impaired physiologic functions. This damage is stemmed by an adequate antioxidant status, which minimizes the occurrence of infection, thus potentially playing a role in improving nutritional status. The role played by genetic factors remains unknown.

OBJECTIVE

The aim of this study was to investigate whether a single nucleotide polymorphism (SNP) of a gene coding for endogenous antioxidant enzymes could influence either nutritional status or renutrition process in an elderly population.

DESIGN

Nutritional and inflammatory status were studied in 77 elderly outpatients and in 99 malnourished elderly inpatients over 6 wk of health care treatment. Renutrition efficiency was evaluated with use of the ratio between initial transthyretinemia and 6-wk variation. A genetic study was performed on superoxide dismutase (Ala-9Val), glutathione peroxidase (Pro197Leu), and catalase (from promoter to the first intron).

RESULTS

Among the SNPs studied, the G-844A, A-89T, and C-20T catalase SNPs could each be markers predicting renutrition efficiency. These catalase mutant alleles were associated with a lower efficiency of renutrition in malnourished elderly subjects, regardless of initial nutritional and inflammatory status. Genotyping one of these catalase SNPs could make it possible to identify a high-risk subpopulation of mutant allele carriers within the elderly polypathological population.

CONCLUSION

In a malnutrition setting, this subpopulation should be given personalized health care, including a strengthened refeeding program. Thus, catalase genotyping could enable earlier recovery of satisfactory nutritional status and thus avoid the consequences of malnutrition, which are especially deleterious in the elderly.

Superoxide dismutase protects against apoptosis and alveolar enlargement induced by ceramide

The molecular events leading to emphysema development include generation of oxidative stress and alveolar cell apoptosis. Oxidative stress upregulates ceramides, proapoptotic signaling sphingolipids that trigger further oxidative stress and alveolar space enlargement, as shown in an experimental model of emphysema due to VEGF blockade. As alveolar cell apoptosis and oxidative stress mutually interact to mediate alveolar destruction, we hypothesized that the oxidative stress generated by ceramide is required for its pathogenic effect on lung alveoli. To model the direct lung effects of ceramide, mice received ceramide intratracheally (Cer(12:0) or Cer(8:0); 1 mg/kg) or vehicle. Apoptosis was inhibited with a general caspase inhibitor. Ceramide augmentation shown to mimic levels found in human emphysema lungs increased oxidative stress, and decreased, independently of caspase activation, the lung superoxide dismutase activity at 48 h. In contrast to their wild-type littermates, transgenic mice overexpressing human Cu/Zn SOD were significantly protected from ceramide-induced superoxide production, apoptosis, and air space enlargement. Activation of lung acid sphingomyelinase in response to ceramide treatment was abolished in the Cu/Zn SOD transgenic mice. Since cigarette smoke-induced emphysema in mice is similarly ameliorated by the Cu/Zn SOD overexpression, we hypothesized that cigarette smoke may induce ceramides in the mouse lung. Utilizing tandem mass spectrometry, we documented increased lung ceramides in adult mice exposed to cigarette smoke for 4 wk. In conclusion, ceramide-induced superoxide accumulation in the lung may be a critical step in ceramide's proapoptotic effect in the lung. This work implicates excessive lung ceramides as amplifiers of lung injury through redox-dependent mechanisms.

Maternal active or passive smoking causes oxidative stress in cord blood

The aim of this study was to assess the influence of active and passive maternal smoking on cord blood total oxidant/antioxidant status at term. The levels of cord blood catalase (CAT), paraoxonase 1 (PON1), ceruloplasmin, total thiol and lipid hydroperoxide (LOOH), total antioxidant capacity (TAC), total oxidant status (TOS) and the oxidative stress index (OSI) were measured in samples of fetal cord blood serum from 29 nonsmokers who were not exposed to active or passive smoke, 30 passive smokers and 21 active smokers. The gestation period of all pregnancies was between 37 and 40 weeks, the pregnancies were uncomplicated and the infants were delivered vaginally. The weights of infants borne to the active smokers were significantly (P < 0.01) lower than those borne to the controls. Significantly lower concentrations of CAT, PON1 and TAC were found in the cord blood of the smokers than in that of the nonsmokers (P < 0.018). The cord blood levels of LOOH and TOS and OSI were significantly higher in the active and passive smokers than in the controls (P < 0.01). A significant positive correlation was found between maternal tobacco exposure and cord blood OSI (P < 0.001). Active or passive maternal smoking is associated with important alterations in the balance of oxidants and antioxidants in fetal cord blood and causes potent oxidative stress.

Effects of melatonin on the oxidant/antioxidant status and lung histopathology in rabbits exposed to cigarette smoke

OBJECTIVES AND BACKGROUND

To evaluate the effects of cigarette smoking on the histopathology and the oxidant/antioxidant status of the lungs and to test the potential antioxidant benefits of melatonin on these induced changes.

METHODOLOGY

Rabbits were exposed to cigarette smoke in a glass chamber for 1 h daily for 1 month with or without intraperitoneal melatonin injection. A melatonin control group was given intraperitoneal melatonin only. A control group was exposed to clean air only. At the end of 1 month, animals were sacrificed and lung tissues were examined histopathologically. Blood levels of protein sulphydryls, carbonyls, prostaglandin F2alpha (PGF2alpha), malondialdehyde (MDA), glutathione peroxidase and superoxide dismutase (SOD) were measured.

RESULTS

Intraparenchymal vascular congestion and thrombosis, intraparenchymal haemorrhage, respiratory epithelial proliferation, number of macrophages in the alveolar and bronchial lumen, alveolar destruction, emphysematous changes and bronchoalveolar haemorrhage scores were significantly increased in rabbits exposed to cigarette smoke compared with the control group. Protein sulphydryls and SOD levels were significantly decreased; carbonyls, PGF2alpha and MDA levels were significantly increased in the smoke exposed rabbits. Administration of melatonin to rabbits exposed to cigarette smoke caused a reduction in the bronchoalveolar haemorrhage score and blood carbonyls levels. Other parameters were unaffected by melatonin.

CONCLUSION

Exposure to cigarette smoke causes severe histopathological changes and negatively affects the oxidant/antioxidant status in the lungs of rabbits. A low daily dose of melatonin has some protective effects on histopathological changes and oxidant/antioxidant status of the lungs in smoke exposed rabbits.

Oxidant–Antioxidant Balance in Patients with COPD

The goal of this study was to evaluate the role of oxidant-antioxidant balance in the pathogenesis of COPD. We included 30 healthy nonsmokers [24 male, 6 female; mean age (yr) +/- SD: 62.4 +/- 9.3], 30 healthy smokers [27 male, 3 female; mean age (yr) +/- SD: 58.7 +/- 6.0], 71 patients with stable COPD [68 male, 3 female; mean age (yr) +/- SD: 63.5 +/- 7.9], and 31 patients with COPD exacerbation [30 male, 1 female; mean age (yr) +/- SD: 64.2 +/- 7.3]. In all study groups the peripheral venous blood samples were taken for plasma malonyldialdehyde (MDA), a parameter of lipid peroxidation caused by the oxidants, and erythrocyte superoxide dismutase (SOD), an antioxidant enzyme. The mean plasma MDA level was higher in healthy smokers and in patients with COPD than in healthy nonsmokers (p < 0.05), and erythrocyte SOD enzyme activity in patients with COPD exacerbation (1048.2 +/- 226.5 Ug/Hb) was significantly higher than in healthy nonsmokers (947.9 +/- 198.0 Ug/Hb) (p < 0.05). Although mean erythrocyte SOD enzyme activity in healthy smokers and patients with stable COPD was higher than in healthy nonsmokers, the difference was not statistically significant. We found that healthy smokers and stable and exacerbated COPD patients had an impairment in oxidant-antioxidant balance. We suggested that new therapeutic interventions, which may repair the impaired oxidant-antioxidant balance in COPD, are needed to prevent the development of COPD.

Increased oxidative stress in infants exposed to passive smoking

The purpose of this study was to assess the effect of passive cigarette smoking on the oxidative and anti-oxidative status of plasma in infants. Eighty-four infants aged 6-28 weeks were divided into two groups: the study group included infants who had been exposed to passive smoking via at least five cigarettes per day for at least the past 6 weeks at home, while the control group included infants who had never been exposed to passive smoking. The antioxidative status of plasma was assessed by the measurement of individual antioxidant components: vitamin C, albumin, bilirubin, uric acid, thiol contents and total antioxidant capacity (TAC 1 and TAC 2). Oxidative status was assessed by the determination of total peroxide levels and the oxidative stress index (OSI 1 and OSI 2). Plasma vitamin C, thiol concentration and TAC 1 and TAC 2 levels were significantly lower, whereas plasma total peroxide levels and OSI 1 and OSI 2 were significantly higher, in passive smoking infants than in the controls (P<0.01). We conclude that passive smoking has a negative impact on numerous parts of the antioxidant defence system in infants, and exposes them to potent oxidative stress.

Secondhand smoke as an acute threat for the cardiovascular system: a change in paradigm

The evidence that active smoking is a risk factor for cardiovascular disease (CVD) and the leading cause of preventable death is overwhelming. However, numerous epidemiological findings indicate that even passive exposure to cigarette smoke may exert detrimental effects on vascular homoeostasis. Recent experimental data provide a deeper insight into the pathophysiological mechanisms linking secondhand smoke (SHS) to CVD. Importantly, most of these effects appear to be characterized by a rapid onset. For example, the relatively low doses of toxins inhaled by passive smoking are sufficient to elicit acute endothelial dysfunction, and these effects may be related, at least in part, to the inactivation of nitric oxide. Moreover, passive smoking may directly impair the viability of endothelial cells and reduce the number and functional activity of circulating endothelial progenitor cells. In addition, platelets of non-smokers appear to be susceptible to pro-aggregatory changes with every passive smoke exposure. Overall, SHS induces oxidative stress and promotes vascular inflammation. Apart from vasoconstriction and thrombus formation, however, the myocardial oxygen balance is further impaired by SHS-induced adrenergic stimulation and autonomic dysfunction. These data strongly suggest that passive smoking is capable of precipitating acute manifestations of CVD (atherothrombosis) and may also have a negative impact on the outcome of patients who suffer acute coronary syndromes.

Genotoxicity of environmental tobacco smoke: a review

Environmental tobacco smoke (ETS), or second-hand smoke, is a widespread contaminant of indoor air in environments where smoking is not prohibited. It is a significant source of exposure to a large number of substances known to be hazardous to human health. Numerous expert panels have concluded that there is sufficient evidence to classify involuntary smoking (or passive smoking) as carcinogenic to humans. According to the recent evaluation by the International Agency for Research on Cancer, involuntary smoking causes lung cancer in never-smokers with an excess risk in the order of 20% for women and 30% for men. The present paper reviews studies on genotoxicity and related endpoints carried out on ETS since the mid-1980s. The evidence from in vitro studies demonstrates induction of DNA strand breaks, formation of DNA adducts, mutagenicity in bacterial assays and cytogenetic effects. In vivo experiments in rodents have shown that exposure to tobacco smoke, whole-body exposure to mainstream smoke (MS), sidestream smoke (SS), or their mixture, causes DNA single strand breaks, aromatic adducts and oxidative damage to DNA, chromosome aberrations and micronuclei. Genotoxicity of transplacental exposure to ETS has also been reported. Review of human biomarker studies conducted among non-smokers with involuntary exposure to tobacco smoke indicates presence of DNA adducts, urinary metabolites of carcinogens, urinary mutagenicity, SCEs and hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutations (in newborns exposed through involuntary smoking of the mother). Studies on human lung cancer from smokers and never-smokers involuntarily exposed to tobacco smoke suggest occurrence of similar kinds of genetic alterations in both groups. In conclusion, these overwhelming data are compatible with the current knowledge on the mechanisms of carcinogenesis of tobacco-related cancers, occurring not only in smokers but with a high biological plausibility also in involuntary smokers.

Direct placental effects of cigarette smoke protect women from pre-eclampsia: the specific roles of carbon monoxide and antioxidant systems in the placenta

Pre-eclampsia is a hypertensive disorder of pregnancy characterized by shallow placentation, inadequate placental perfusion, localized placental oxidative stress, a heightened maternal inflammatory response and subsequent maternal endothelial dysfunction. This pathophysiology leads to an increase in maternal blood pressure, edema and proteinurea. Interestingly, women who smoke cigarettes throughout pregnancy are at a 33% reduced risk of developing this disorder. The exact mechanisms through which cigarette smoke reduces the risk of pre-eclampsia are not yet understood. We propose that cigarette smoke reduces the risk of developing pre-eclampsia via direct placental effects. In this review we will address, and provide evidence for, our specific hypotheses that: (a) CO increases trophoblast invasion and spiral arteriole remodeling; (b) CO decreases a localized inflammatory response at the level of the decidua; (c) CO increases utero-placental, intra-placental and feto-placental blood flow; (d) CO decreases hypoxia-induced apoptosis of the syncitiotrophoblast layer; (e) CO activates hemoproteins involved in normal endothelial functioning normally acted upon by NO; (f) compound(s) within cigarette smoke result in upregulation of antioxidant systems within the placenta. These various mechanisms of action must be further examined as they may provide valuable keys to novel therapeutic design in the realm of pre-eclampsia research.

An 18-month follow-up study on the influence of smoking on blood antioxidant status of teenage girls in comparison with adult male smokers in Korea

OBJECTIVES

The influence of cigarette smoking on blood antioxidant status in teenage girls with a history of short-term smoking was followed over 18 mo.

METHODS

Data obtained from female senior high school students (ages 14 to 18 y) in Korea were compared with data obtained from adult male smokers (ages 36 to 51 y) with a long history of smoking and living in the same geographic areas as the teenage subjects. A smoker was a person who had smoked at least three cigarettes a day for at least 1 y for teenagers (n = 35) or at least 10 cigarettes a day for at least 13 y for adults (n = 20). Serum, urine, and anthropometric data were obtained from teenagers every 6 mo over an 18-mo period. Samples were collected once from adults. Data were analyzed by Student's t test and Fisher's protected least significant difference test for comparing smokers and non-smokers and for analyzing period effects in each group.

RESULTS

Serum nicotine and cotinine concentrations were higher in smokers than in non-smokers. Blood pressures were higher in teenage (at 0 and 12 mo) and adult smokers than in non-smokers. Extracellular superoxide dismutase activities and concentrations of serum vitamin C and folate were lower in smokers in the teenage (at 0, 12, or 18 mo) and adult groups. Serum ceruloplasmin activities and thiobarbituric acid-reactive substance production were not influenced by smoking. In adults, serum copper concentrations were higher in smokers than in non-smokers. This parameter for teenagers did not change consistently throughout the study.

CONCLUSIONS

Similar to adults, cigarette smoking by teenagers has a negative effect on oxidant defense systems.