Age-related sex differences in glutathione peroxidase and oxidative DNA damage in a healthy Mexican population

Pre-exercise cryotherapy reduces myoglobin and creatine kinase levels after eccentric muscle stress in young women

Introduction: The aim of this study was to investigate the effect of pre-exercise whole-body cryotherapy (WBC) on muscle damage indicators following eccentric treadmill exercise in young women. Methods: Twenty-seven participants underwent two 1-h downhill treadmill runs, replicating 60% of their maximal oxygen uptake, with a 4-week intermission for recovery and treatment application. In this intermission, one group underwent 20 sessions of WBC, delivered five times a week at -120°C for 3 min each, while the comparison group received no such treatment. Markers of muscle injury-serum myoglobin concentration, creatine kinase and lactate dehydrogenase activity and also uric acid, and cell-free DNA concentration-were measured before and after downhill runs. Results: The study observed a notable reduction in post-exercise myoglobin and CK levels in the WBC group after the second running session. Discussion: The results suggest that WBC can have a protective effects against muscle damage resulting from eccentric exercise.

Association between oxidative stress exposure and colorectal cancer risk in 98,395 participants: results from a prospective study

Background

The intricate role of oxidative stress (OS) in colorectal cancer (CRC) initiation is underscored by an imbalance between pro-oxidants and antioxidants. Utilizing the Oxidative Balance Score (OBS) as a metric, this study aims to investigate the association between OS exposure and CRC risk, while also examining potential sex-specific differences in a large U.S. cohort.

Methods

The study included 98,395 adults from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. To construct the OBS, 14 dietary and lifestyle factors intricately associated with oxidative stress were quantified. A higher OBS value indicated a more favorable oxidative balance pattern or diminished OS exposure. Due to sex-specific differences in OBS, associations were evaluated separately for men and women based on Cox regression analysis. Subgroup analyses were conducted to elucidate potential modifiers.

Results

During 867,963.4 person-years of follow-up, 1,054 CRCs occurred. The mean (SD) age and OBS were 65.52 (5.73) years and 14.09 (3.95) points, respectively. In the fully adjusted Cox model, we observed an inverse association between OBS and CRC incidence in women (HRQ5vsQ1: 0.72; 95% CI: 0.52, 0.99; P for trend = 0.018) but not men. Subgroup analyses revealed the inverse association was more pronounced among women without versus with a family history of CRC (HRQ5 vsQ1: 0.66, 95% CI: 0.47-0.93; P for trend = 0.001; P for interaction = 0.001). The results remained robust after several sensitivity analyses.

Conclusion

Higher OBS was associated with lower CRC risk in women but not men; this inverse association was stronger among women without a family history of CRC. These findings suggest exposure to OS may confer sex-specific CRC risk effects, especially for women without a family history of CRC.

Gender Differences in Oxidative Stress in Relation to Cancer Susceptibility and Survival

Genetic, developmental, biochemical, and environmental variables interact intricately to produce sex differences. The significance of sex differences in cancer susceptibility is being clarified by numerous studies. Epidemiological research and cancer registries have revealed over the past few years that there are definite sex variations in cancer incidence, progression, and survival. However, oxidative stress and mitochondrial dysfunction also have a significant impact on the response to treatment of neoplastic diseases. Young women may be more protected from cancer than men because most of the proteins implicated in the regulation of redox state and mitochondrial function are under the control of sexual hormones. In this review, we describe how sexual hormones control the activity of antioxidant enzymes and mitochondria, as well as how they affect several neoplastic diseases. The molecular pathways that underlie the gender-related discrepancies in cancer that have been identified may be better understood, which may lead to more effective precision medicine and vital information on treatment options for both males and females with neoplastic illnesses.

A comparative meta-analysis of peripheral 8-hydroxy-2'-deoxyguanosine (8-OHdG) or 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) levels across mood episodes in bipolar disorder

OBJECTIVE

Oxidative DNA damage has been associated with the pathophysiology of bipolar disorder (BD) as one of the common pathways between increased medical comorbidity and premature aging in BD. Previous evidence shows increased levels of oxidatively induced DNA damage markers, 8-hydroxy-2'-deoxyguanosine (8-OHdG) or its tautomer 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG), in patients with BD in comparison to healthy individuals. With the current research, we aim to analyze data on peripheral (blood or urine) 8-OHdG/8-oxo-dG levels across mood states of BD using a meta-analytical approach.

METHOD

A literature search was conducted using the databases PubMed, Scopus, and Web of Science to identify eligible studies (January 1989 to July 2022). Relevant studies were systematically reviewed; a random-effects meta-analysis and a meta-regression analysis were conducted.

RESULTS

The current meta-analysis included 12 studies consisting of 808 BD patients (390 in euthymia, 156 in mania, 137 in depression, 16 in mixed episode, 109 not specified) and 563 healthy controls. BD patients that were currently depressed had significantly higher levels of 8-OHdG/8-oxo-dG than healthy controls, while euthymic or manic patients did not differ from healthy controls. A meta-regression analysis showed sex distribution (being female) and older age to be significantly related to increased 8-OHdG/8-oxo-dG levels.

CONCLUSION

Our findings suggest that 8-OHdG/8-oxo-dG may be a state-related marker of depression in BD and may be affected by older age and female gender.

Sex differences in markers of oxidation and inflammation. Implications for ageing

Sexual dimorphism is a key factor to consider in the ageing process given the impact that it has on life expectancy. The oxidative-inflammatory theory of ageing states that the ageing process is the result of the establishment of oxidative stress which, due to the interplay of the immune system, translates into inflammatory stress, and that both processes are responsible for the damage and loss of function of an organism. We show that there are relevant gender differences in a number of oxidative and inflammatory markers and propose that they may account for the differential lifespan between sexes, given that males display, in general, higher oxidation and basal inflammation. In addition, we explain the significant role of circulating cell-free DNA as a marker of oxidative damage and an inductor of inflammation, connecting both processes and having the potential to become a useful ageing marker. Finally, we discuss how oxidative and inflammatory changes take place differentially with ageing in each sex, which could also have an impact on the sex-differential lifespan. Further research including sex as an essential variable is needed to understand the grounds of sex differences in ageing and to better comprehend ageing itself.

Association between atmospheric pollutant levels and oxidative stress in pregnant women and newborns in Urumqi

BACKGROUND

Frequent heavy air pollution occurred during the winter heating season of northern China. Particulate air pollution is a serious concern in Urumqi during heating season. Exposure to air pollution is known to increase adverse health outcomes, particularly oxidative damage. This study aimed to evaluate the impact of air pollution on oxidative damage around pregnant women and newborns in Urumqi.

METHODS

This prospective observational study enrolled pregnant women in the Fifth Affiliated Hospital of Xinjiang Medical University between January 2019 and October 2019. Pregnant women and newborns were allocated into a heating season group (January - end of April 2019, October 2019) or non-heating season group (June 2019 - end of September) according to the specific delivery time. Venous blood, urine from the women and cord blood from their newborns were collected to measure the levels of PAHs and 8-deoxyguanosine (8-OHdG), a measure of oxidative stress.

RESULTS

A total of 200 pregnant women and newborns were enrolled, with 100 pregnant women and newborns in the heating season group. Compared to the non-heating season group, the total contents of 8-OHdG in maternal urine, PAHs and 8-OHdG in maternal plasma and neonatal cord blood were higher in the heating season group (all P < 0.001). The average values for AQI, PM_2.5, PM₁₀, SO₂, NO₂, and CO were higher in the heating season group (all P < 0.001). Maternal and neonatal PAHs were correlated with 8-OHdG measurements in maternal urine (r = 0.288, P < 0.001 and r = 0.336, P < 0.001) and neonatal umbilical cord blood (r = 0.296, P < 0.001 and r = 0.252, P < 0.001). There was also a positive relationship between PAHs, 8-OHdG levels in pregnant women and their newborns and proximate air pollutant concentrations (all P < 0.05). Based on the results of multiple linear regression analysis, it was found that air pollutants(PM₁₀, 0₃) had a great influence on the level of 8-OHdG in neonatal cord blood, and the contribution rate was high(R² = 0.320). Based on the epidemiological questionnaire, a multiple linear regression model was established(R² = 0.496). We found that 8-OHdG levels in neonatal umbilical cord blood were mainly affected by two aspects: (1) Biological samples collected during heating had higher levels of 8-OHdG in neonatal umbilical cord blood. (2) Study may suggest that in neonates, males are more sensitive to oxidative damage.

CONCLUSION

Particulate air pollution may increase PAHs exposure and oxidative DNA damage in pregnant women and newborns.

A study of the oxidative processes in human plasma by time-resolved fluorescence spectroscopy

The aim of this study was to examine the usefulness of time-resolved fluorescence spectroscopy in the evaluation of the oxidative processes in human plasma. To investigate the impact of oxidative stress on the fluorescence of plasma, five studied markers (thiobarbituric acid-reactive substances, ischemia modified albumin, carbonyl groups, hydrogen peroxide, advanced oxidation protein products) were chosen as oxidative damage approved markers. Our method presents several advantages over traditional methods as it is a direct, non-time-consuming, repeatable, and non-invasive technique that requires only simple pre-treatment of samples without additional reagents and the sample size needed for analysis is small. In principle, each modification of the protein in plasma can be expected to modify its fluorescence properties and hence its lifetime or intensity. The study involved 59 blood donors with no evidence of disease. The research was conducted at excitation wavelengths of 280 nm and 360 nm, and emission was measured at wavelengths of 350 nm and 440 nm, respectively. Our results, although preliminary, suggest that the application of fluorescence measurements can be considered as an effective marker of oxidative stress. Regression analyses showed that a notable growth in fluorescence intensity at 440 nm and a simultaneous decrease in fluorescence intensity and mean fluorescence lifetime at 350 nm are associated with higher levels of oxidative stress.

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.

[Deletion polymorphism of GSTT1 gene and lipid peroxidation hyperactivation in menopausal insomnia]

OBJECTIVE

A comparative analysis of the parameters of lipid peroxidation - antioxidant defense system in menopausal women with- and without insomnia, depending on the GSTT1 polymorphism.

MATERIAL AND METHODS

The study included 181 menopausal Caucasian women (ethnic group - Russians), who according to the results of the clinical-anamnestic examinations were divided into insomnia group (n=120, age 53.68±4.61 years, body mass index 26.47±3.73 kg/m²) and control group (n=61, age 52.64±4.91 years, body mass index 27.69±3.11 kg/m²). The insomnia group was formed according to the clinical guidelines for the diagnosis and treatment of chronic insomnia in adults, and scores of the Insomnia Severity Index. The study of the GSTT1 gene polymorphism was carried out using polymerase chain reaction. The lipid peroxidation - antioxidant system parameters were determined by spectrofluorophotometric methods.

RESULTS

In the insomnia group, carriers of the normal GSTT1 genotype had higher diene conjugates with lower glutathione peroxidase activity as compared to controls. When comparing groups of women with the deletion in GSTT1, an increase in the content of substrates and lipid peroxidation products was observed at all stages of lipid peroxidation, oxidized glutathione, glutathione S-transferase activity with a decrease in the content of reduced glutathione and retinol in the insomnia group as compared to controls. In the insomnia group, carriers of the deletion genotype had a higher content of ketodienes/conjugated trienes and active products of thiobarbituric acid, a lower content of retinol and α-tocopherol as compared to the patients with normal GSTT1 genotype. Conclusions. Insomnia in the menopausal women is accompanied with the intensification of lipid peroxidation only in the carriers of the GSTT1 deletion genotype.

Preliminary Study on the Tears Oxidative Stress Status and Sleep Disturbances in Irritable Bowel Syndrome Patients

According to the latest gastrointestinal disorders diagnostic criteria (ROME IV), the irritable bowel syndrome (IBS) is mainly characterized by the presence of abdominal pain and changes in intestinal transit. However, both sleep impairments and oxidative status changes (in patients' sera, mucosal level, and other body fluids) were reported IBS. Thus, in this study, we aimed to evaluate several aspects regarding the oxidative stress status in patients' tears as well as sleep disturbances by comparison with the intensity of IBS symptoms, as assessed by the visual analogue scale for irritable bowel syndrome (VAS-IBS). Ten IBS patients and fourteen healthy sex- and age-matched volunteers were recruited from the Oftaprof Ophthalmological Clinic (Iași, Romania). Visual analogue scale for irritable bowel syndrome and the Pittsburgh Sleep Quality Index (PSQI) questionnaires were administered to all the patients. Tear samples were collected using the Schirmer test procedure and were subjected to biochemical analysis-superoxide dismutase and glutathione peroxidase activities, malondialdehyde, and total soluble proteins levels were determined. Standard statistical analysis was applied. We found significant differences in oxidative stress marker dynamics in IBS patients as compared to healthy age- and sex-matched controls: increased superoxide dismutase activity (p = 0.02), increased malondialdehyde (p = 0.007), and total soluble proteins levels (p = 0.019). We found no significant differences in tear glutathione peroxidase activity in IBS patients as compared to healthy age- and sex-matched controls (p = 0.55). Furthermore, we observed that the oxidative stress tear markers are correlated with gastrointestinal symptoms severity (as evaluated by VAS-IBS) but not correlated to the sleep quality index and items (as evaluated by PSQI), with significant differences according to patient sex and IBS subtype stratification. In this way, this study brings additional evidence of the oxidative stress role in IBS pathology alongside the evaluation of tear fluid molecular dynamics in IBS for the first time in our best knowledge.

Free Radical Oxidation and Sleep Disorders in Andro- and Menopause (Literature Review)

This review presents data on changes in the physiology of sleep during reproductive aging. It is noted that insomnia and obstructive sleep apnea syndrome (OSAS) are the main sleep disorders. The results of foreign and domestic studies in the field of free radical oxidation during sleep deprivation in animal models are presented, indicating the dependence of processes on the duration of sleep deprivation. The largest number of studies of free radical processes in a person with somnological pathology was carried out in the study of OSAS. Blood, urine, saliva, condensate of exhaled air can be biomaterial for determining the parameters of free radical oxidation. It was shown that the intensity of oxidative stress depends on the severity of OSAS, as evidenced by the positive correlation of the level of active products of thiobarbituric acid, the products of oxidation of proteins and carbonyl groups with the apnea/hypopnea index, determining the development of not only oxidative, but also carbonyl stress in patients with a severe degree OSAS. Biomarkers such as thioredoxin, malondialdehyde, superoxide dismutase, and reduced iron have shown a more stable relationship between increased oxidative stress and OSA. Despite the results obtained, the question of the association of oxidative stress and hypoxia in OSA remains debatable, which is associated with the opposite results of some studies. Insomnia, which occurs mainly in females, is accompanied by a high level of end products of lipid peroxidation with a decrease in the activity of antioxidants such as paraoxonase, an enzymatic component of the glutathione system. Along with this, menopausal women present low levels of uric acid, which correlates with high scores of the Pittsburgh sleep quality index questionnaire. Recent studies have identified an association between the activity of the «lipoperoxidation – antioxidants» system and the Clock 3111T/C gene polymorphism in menopausal Caucasian women, indicating the protective role of the minor allele.

Application of the comet assay in human biomonitoring: An hCOMET perspective

The comet assay is a well-accepted biomonitoring tool to examine the effect of dietary, lifestyle, environmental and occupational exposure on levels of DNA damage in human cells. With such a wide range of determinants for DNA damage levels, it becomes challenging to deal with confounding and certain factors are inter-related (e.g. poor nutritional intake may correlate with smoking status). This review describes the effect of intrinsic (i.e. sex, age, tobacco smoking, occupational exposure and obesity) and extrinsic (season, environmental exposures, diet, physical activity and alcohol consumption) factors on the level of DNA damage measured by the standard or enzyme-modified comet assay. Although each factor influences at least one comet assay endpoint, the collective evidence does not indicate single factors have a large impact. Thus, controlling for confounding may be necessary in a biomonitoring study, but none of the factors is strong enough to be regarded a priori as a confounder. Controlling for confounding in the comet assay requires a case-by-case approach. Inter-laboratory variation in levels of DNA damage and to some extent also reproducibility in biomonitoring studies are issues that have haunted the users of the comet assay for years. Procedures to collect specimens, and their storage, are not standardized. Likewise, statistical issues related to both sample-size calculation (before sampling of specimens) and statistical analysis of the results vary between studies. This review gives guidance to statistical analysis of the typically complex exposure, co-variate, and effect relationships in human biomonitoring studies.

Effect of age and sex on the level of DNA strand breaks and oxidatively damaged DNA in human blood cells

DNA damage measured by the comet assay is a well-established biomarker in studies on environmental and occupational exposures, dietary factors and clinical outcomes. Age and sex are typically regarded as confounding factors that are controlled by either selective inclusion criteria of subjects or adjustment in the statistical analysis. This review assesses the influence of age and sex on levels of DNA damage in leukocytes in study populations of healthy subjects. Analysis of unadjusted results in the studies indicates that the level of DNA strand breaks increases by 1% per year (95% CI: 0.9%-1.1%, linear regression analysis weighted for the number of subjects in the individual studies). The studies also show a slightly higher level of DNA strand breaks in men than women (8%, 95% CI: 0.4%-17%) in unadjusted analyses, which is not robust in studies with adjusted analyses. The attenuation of effect in adjusted analyses of DNA strand breaks in leukocytes indicates that the effect of age and sex may be driven by differences in lifestyle factors or other exposures. There do not appear to be differences related to age and sex on basal levels of oxidatively damaged DNA in leukocytes. In summary, the results indicate influences of both age and sex on DNA damage in the comet assay, which may be mediated by lifestyle factors or external exposures rather than direct effects of age and sex.

Intrauterine Hyperglycemia Is Associated with an Impaired Postnatal Response to Oxidative Damage

Hyperglycemia and other adverse exposures early in life that reprogram stem cells may lead to long-lasting phenotypic influences over the lifetime of an individual. Hyperglycemia and oxidative stress cause DNA damage when they exceed the protective capabilities of the cell, in turn affecting cellular function. DNA damage in response to hyperglycemia and oxidative stress was studied in human umbilical cord mesenchymal stem cells (hUC-MSCs) from large-for-gestational-age (LGA) infants of mothers with gestational diabetes mellitus (LGA-GDM) and control subjects. We tested the response of these cells to hyperglycemia and oxidative stress, measuring reactive oxygen species (ROS) levels and antioxidant enzyme activities. We find that hUC-MSCs from LGA-GDM infants have increased DNA damage when exposed to oxidative stress. With the addition of hyperglycemic conditions, these cells have an increase in ROS and a decrease in antioxidant glutathione peroxidase (GPx) activity, indicating a mechanism for the increased ROS and DNA damage. This study demonstrates that a memory of in utero hyperglycemia, mediated through downregulation of GPx activity, leads to an increased susceptibility to oxidative stress. The alteration of GPx function in self-renewing stem cells, can mediate the effect of intrauterine hyperglycemia to be propagated into adulthood and contribute to disease susceptibility.

DNA redox modulations and global DNA methylation in bipolar disorder: Effects of sex, smoking and illness state

DNA redox modulations and methylation have been associated with bipolar disorder (BD) pathophysiology. We aimed to investigate DNA redox modulation and global DNA methylation and demethylation levels in patients with BD during euthymia, mania or depression in comparison to non-psychiatric controls. The roles of sex and smoking as susceptibility factors for DNA redox modulations and global DNA methylation and demethylation were also explored. Levels of 5-methylcytosine (5-mC), 5-hydroxymethylcytosine (5-hmC) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were assessed in DNA samples of 75 patients with DSM-IV BD type I (37 euthymic, 18 manic, 20 depressive) in comparison to 60 non-psychiatric controls. Levels of 5-mC and 5-hmC were assessed using Dot Blot as a screening process, and verified using ELISA. Levels of 8-OHdG were assessed using ELISA. The levels of 8-OHdG significantly differed among non-psychiatric control, euthymia, mania and depression groups [F (3,110) = 2.771, p = 0.046], whereas there were no alterations in the levels of 5-hmC and 5-mC. Linear regression analyses revealed the significant effects of smoking (p = 0.031) and sex (p = 0.012) as well as state of illness on the levels of 8-OHdG (p = 0.025) in patients with BD. Our results suggest that levels of 8-OHdG may be affected by sex, illness states and smoking in BD.

Oxidative stress in women with insomnia in different stages of menopause

Aim. To investigate of a lipid peroxidation (LPO) process and the antioxidant defense system (ADS) in peri- and postmenopausal women with insomnia. Subjects and methods. 47 perimenopausal women and 71 postmenopausal ones were examined. Each group was divided into 2 subgroups: 1) individuals with insomnia and 2) controls. LPO-ADS spectrophotometric studies were used in the investigation. Results. There was an increase in the serum levels of ketodienes and conjugated trienes and a decrease in those of α-tocopherol and retinol in postmenopause versus in perimenopause. In insomnia, there was a rise in the level of ketodienes and conjugated trienes in perimenopause; LPO substrates with conjugated double bonds, diene conjugates, and thiobarbituric acid-active products in postmenopause. The indicators of ADS do not differ from those in the controls. The integral indicator of oxidative stress assessment suggests that there is a LPO-ADS imbalance in the menopausal women with insomnia, which is most pronounced in postmenopause. Conclusion. The findings suggest that the patients with insomnia develop oxidative stress that is more marked in postmenopause.

Oxidative stress response and Nrf2 signaling in aging

Increasing oxidative stress, a major characteristic of aging, has been implicated in a variety of age-related pathologies. In aging, oxidant production from several sources is increased, whereas antioxidant enzymes, the primary lines of defense, are decreased. Repair systems, including the proteasomal degradation of damaged proteins, also decline. Importantly, the adaptive response to oxidative stress declines with aging. Nrf2/EpRE signaling regulates the basal and inducible expression of many antioxidant enzymes and the proteasome. Nrf2/EpRE activity is regulated at several levels, including transcription, posttranslation, and interactions with other proteins. This review summarizes current studies on age-related impairment of Nrf2/EpRE function and discusses the changes in Nrf2 regulatory mechanisms with aging.

A Case–Control Study Examining the Effects of Active Versus Sedentary Lifestyles on Measures of Body Iron Burden and Oxidative Stress in Postmenopausal Women

Approximately half of the Canadian adults have sedentary lifestyles that increase their risk of developing cardiovascular disease (CVD). Women are 10 times more likely to die from CVD than from any other disease. Their risk almost doubles with the onset of menopause, which may result in increased body iron burden and oxidative stress in sedentary women. Body iron burden may catalyze the production of cytotoxic oxygen species in vivo. We hypothesized that postmenopausal women who engage in moderate forms of aerobic exercise for at least 30 min three or more times per week would have significantly (i) lower levels of body iron burden, (ii) increased glutathione peroxidase (GPx) activity, and (iii) decreased oxidative stress in comparison to sedentary controls. An age-matched, case–control study was employed to examine the effects of active ( N = 25) versus sedentary ( N = 25) lifestyles in women aged 55–65 years on measures of body iron burden as quantified by total serum iron, transferrin saturation, and serum ferritin levels; GPx activity; and oxidative stress as quantified by 4-hydroxynonenal, malondialdehyde, and hexanal. Measures of body iron burden were significantly elevated in sedentary women in comparison to active women ( p < .001). Red cell GPx activity was higher in active women compared to sedentary women ( p < .001). Measures of oxidative stress were significantly higher in sedentary versus active women ( p < .001). These findings suggest that aerobic forms of exercise may mitigate the risk of developing CVD in postmenopausal women by improving antioxidant capacity and decreasing body iron burden.

Quinocetone triggers oxidative stress and induces cytotoxicity and genotoxicity in human peripheral lymphocytes of both genders

BACKGROUND

Quinocetone has been widely used as an animal growth promoter in China. However, available data showed that QCT has potential genotoxicity. This study was conducted to investigate the cytotoxicity and genotoxicity of QCT in human lymphocytes.

RESULTS

CCK-8 assay demonstrated the severe inhibitory effects by QCT in a dose- and time-dependent manner. DNA damage analysis using alkalic Comet assay revealed a pronounced increase of DNA fragmentation in cells. In contrast, DNA damage was significantly decreased after incubation with S9 mix. This finding demonstrated that the intermediate metabolites of this drug exerted lower genotoxicity than its parent drugs. We further described chromosomal damage induced by this drug employing cytokinesis-block micronucleus assay. The micronucleus frequency was significantly increased in quinocetone groups as compared to controls. Similar to the observation in Comet assay, incorporation of S9 mix in the cytokinesis-block micronucleus assay could markedly alleviate the chromosomal damage. Moreover, QCT could invoke increase of reactive oxygen species generation in cells. Intriguingly, the toxicity of QCT was more prominent in samples from males than those from females under the same conditions.

CONCLUSION

QCT could induce potential cytotoxicity and genotoxicity in human lymphocytes.