Urinary Malondialdehyde Levels Research Articles

Peroxinitrite and Malondialdehyde as Biomarkers for Overactive Bladder.

To measure urine malondialdehyde (MDA) and urine peroxynitrite (ONOO) levels in patients with overactive bladder (OAB), and compare them with healthy individuals; to determine the change of those markers in OAB patients prescribed antimuscarinic drugs. An observational study. The Department of Urology, School of Medicine, University of Gaziantep, Gaziantep, Turkey, between August 2021 and February 2022. Patients diagnosed with OAB (Group 1), and healthy controls (Group 2) were compared. Urinary MDA (µmol/L) and ONOO (µmol/L) levels were measured in all participants. The patients diagnosed with OAB were underwent antimuscarinic therapy with propiverine 30 mg. The levels of MDA (µmol/L) and ONOO (µmol/L) were reanalysed during the third month of antimuscarinic therapy. Patients with stress urinary incontinence, neurogenic bladder, pelvic organ prolapse stage ≥3 (POP-Q ≥3), interstitial cystitis (bladder pain syndrome), history of pelvic radiotherapy, symptoms of bladder outlet obstruction, Qmax <10 ml/sec for men and <15 ml/sec for women measured by uroflowmetry, and history of pelvic and incontinence surgery were excluded from the study. There was no difference in the mean age and or gender distribution of the two groups (p=0.166 and p=0.774, respectively). While the mean MDA levels were significantly higher in patients with OAB, (3.34 ± 1.06µmol/L vs. 2.62 ± 1.45µmol/L, p=0.036), no significant change was detected in ONOO levels between the groups (1.03 ± 0.75 µmol/L vs. 0.71 ± 022 µmol/L, p >0.05). Although no significant change was detected in MDA levels after antimuscarinic therapy (3.50 ± 1.19 µmol/L, p=0.529), there was a statistically significant increase in ONOO levels (1.49 ± 1.45 µmol/L, p=0.013). MDA might be used in the diagnosis of OAB, as a biomarker, similar to recent studies. ONOO was evaluated for the first time in the literature for the diagnosis of OAB, unfortunately, no significant outcomes were obtained. In addition, both MDA and ONOO had no role in monitoring antimuscarinic therapy. Overactive bladder, Peroxynitrite, Malondialdehyde.

Health risk assessment of phthalates exposure through lipid peroxidation in children with asthma

Background: Global prevalence of asthma in children has dramatically increased in the past decades. Recent studies revealed that Taiwanese children are still exposed to considerable amounts of phthalates after the 2011 incident of phthalates-tainted food products. Up-to-date findings indicated that phthalates may increase malondialdehyde (MDA), a lipid peroxidation marker, in asthma patients. The role of phthalates in the increased occurrence of childhood asthma through lipid peroxidation remains unclear. We want to assess the association between phthalates exposure and MDA in children with asthma. Methods: We recruited 125 children with clinically-diagnosed asthma and around 98 controls from Taipei Hospital since January 2019. Participants provided urine specimen and questionnaire. Eleven phthalate metabolites and MDA were analyzed by liquid chromatography tandem-mass spectrometry (LC-MS/MS) and ELISA, respectively. Pearson correlation and related statistical method were used to analyze the relationship of urinary phthalate metabolites or MDA in asthma children. Results: BMI in asthma children was significantly higher than that in control (p=0.005) whereas no similar phenomena was observed for other demographic factors. Mother ever had cigarette smoking in pregnancy and current burn incense at home in the case group were marginally significantly higher than those in control. Meanwhile, the median levels of urinary MEHP (72.18 v.s 68.81 ng/mL), MiNP (28.75 v.s 23.51 ng/mL), and MDA (6.87 v.s. 5.86) in asthma children were higher than those in control, though failed to reach statistical significance. Age was positively correlated with urinary MDA (r=0.159, p=0.018) and MEP (r=0.13, p=0.058). Urinary MEP was highly correlated with the other phthalate metabolites which indicated a common exposure source. Conclusion. Certain phthalates may increase lipid peroxidation markers in asthma children. Keyword: Phthalate metabolites; lipid peroxidation; asthma.

Passive smoking and urinary oxidative biomarkers: A pilot study of healthy travelers from Los Angeles to Beijing.

There is a great heterogeneity in smoking prevalence and tobacco control policy across different countries. However, it is unknown whether this heterogeneity could cause increased passive smoking and adverse health effects among international travelers. In this pilot study, we collected 190 urine samples from 26 Los Angeles residents before (LA-before), during (Beijing), and after (LA-after) a 10-week visit to Beijing to measure biomarkers of passive smoking (cotinine), exposure to polycyclic aromatic hydrocarbons (OH-PAHs), and oxidative stress (malondialdehyde, 8-isoprostane, and uric acid). The geometric mean concentrations of urinary cotinine were 0.14, 1.52, and 0.22μg/g creatinine in LA-before, Beijing, and LA-after, respectively. Likewise, OH-PAH levels were significantly higher in Beijing as compared to LA-before or LA-after, in association with the urinary cotinine levels. One-fold increase in urinary cotinine levels was associated with 10.1% (95% CI: 5.53-14.8%), 8.75% (95% CI: 2.33-15.6%), and 25.4% (95%CI: 13.1-39.1%) increases in urinary levels of malondialdehyde, 8-isoprotane, and uric acid, respectively. OH-PAHs mediated 9.1-23.3% of the pro-oxidative effects associated with passive smoking. Taken together, our findings indicate that traveling to a city with higher smoking prevalence may increase passive smoking exposure, in association with pro-oxidative effects partially mediated by PAHs.

Biomarker of Urinary Malondialdehyde and Tumor Necrosis Factor-Alpha with Pain Progress in a Patient with Low Back Pain

Introduction: This study aims to determine the urine concentrations of malondialdehyde (MDA), and tumor necrosis factor-alpha (TNF-α) biomarkers with pain intensity in a patient with low back pain (LBP) compared to healthy controls. Also, the correlation between these biomarkers and clinical findings of pain intensity was determined during 25 weeks to find a molecular diagnostic factor of disease progression. Case Presentation: Participants in this case study are students at Shahed University, Iran. A 22‑year‑old man patient with a three-month history of progressive LBH and gait instability and an age, sex, and body mass index (BMI) matched healthy man was enrolled for 25 weeks. Spinal MRI (Siemens 1.5 T) revealed disc degeneration and displacement. LBP symptoms were diagnosed by a neurologist using ICD-9 diagnostic codes. Other diseases that affect the urine levels of MDA and TNF-α in the patient, such as allergic or infectious diseases, have been ruled out. After collecting demographic information, the facial pain scale (FPS) and numerical rating scale (NRS) for pain and 24-hour urine samples of a healthy person and a patient were collected weekly for 25 weeks. Samples were analyzed for MDA and TNF-α. Conclusions: During the experiment, urinary MDA levels were significantly elevated while TNF-α levels were not changed in LBP patients compared to control individuals (P ≤ 0.001). Furthermore, the assessment of LBP by the FPS and NRS pain scores was only correlated with urinary MDA levels, and urinary TNF-α levels did not change during the experiment. Pearson correlation analysis revealed a positive correlation between pain scores during 25 weeks and urine concentrations of MDA (r = 0.60, P-value &lt; 0.001). According to the present study, chronic LBP patients had higher levels of MDA in their urine than those who did not have chronic LBP. There was a significant positive association between urine MDA level and pain intensity progression.

Exposure assessment of children living in homes with hookah smoking parents to polycyclic aromatic hydrocarbons: urinary level, exposure predictors, and risk assessment.

Children are extremely liable to indoor air pollutants as their physiology and a few metabolic pathways are different from those of adults. The present cross-sectional study aimed to assess exposure of children living with parents who use hookah tobacco smoke to polycyclic aromatic hydrocarbons (PAHs) using a biomonitoring approach. The study was conducted on 25 children (7–13 years of age) exposed to hookah smoke at home and 25 unexposed age-matched children. Urinary levels of five metabolites of PAHs were quantified via headspace gas chromatography-mass spectrometry (GC–MS). Urinary malondialdehyde (MDA) was measured, as well. Information regarding the sociodemographic and lifestyle conditions was collected through interviews using managed questionnaires. The urinary 1-OH-NaP and 9-OH-Phe concentrations were respectively 1.7- and 4.6-folds higher in the case samples compared to the control group (p < 0.05). In addition, urinary MDA levels were 1.4 times higher in the exposed children than in the unexposed group, but the difference was not statistically significant (p > 0.05). Increasing the consumption of grilled and meat food in the diet increased the participants’ urinary 2-OH-Flu and 1-OH-Pyr levels, respectively. Moreover, sleeping in the living room instead of the bedroom at night was a significant predictor of high 1-OH-NaP and 2-OH-NaP concentrations in the children’s urine. Overall, the findings confirmed that children living in their homes with hookah-smoking parents were significantly exposed to naphthalene and phenanthrene. Hence, implementing protective measures is critical to reduce the exposure of this group of children.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-022-20589-0.

Correlation of Serum Nitric Oxide and Urine Malondialdehyde Levels in Non-Hemodialysis Chronic Kidney Disease Patients

Background: In 2017, about 1.2 million people died because of Chronic Kidney Disease (CKD). Patients with CKD are known to have increased levels of oxidative stress which leads to decrease in NO production. NO is a highly reactive signaling molecule and a major determinant of vascular homeostasis. Thus, the decreased NO can be a risk factor for the development of atherosclerosis and increased cardiovascular risk. Meanwhile, Malondialdehyde (MDA) is known as excellent biomarker for oxidative stress. This study aims to determine the correlation of serum total nitric oxide (NO) and urine MDA levels in non-hemodialysis CKD patients.Materials and Methods: This study was an observational clinical study with a cross sectional design. Fourty-nine CKD subjects were selected by consecutive sampling. The samples for laboratory tests were collected from urine. MDA concentration was measured using the High-Performance Liquid Chromatography (HPLC) kit. NO concentration was measured with Griess reaction method and Total Nitric Oxide Parameter kit. The data were analyzed using the Statistic Package for Social Science (SPPS) software version 16.Results: The data showed significant negative correlations between MDA with NO (r=-0.294; p=0.041).Conclusion: There was a correlation between serum total NO and urine MDA levels in non-hemodialysis CKD patients.Keywords: chronic kidney disease, malondialdehyde, nitric oxide, non-hemodialysis

Characterization of the L-Arginine/Nitric Oxide Pathway and Oxidative Stress in Pediatric Patients with Atopic Diseases.

Introduction: L-Arginine (Arg) is a semi-essential amino acid. Constitutive and inducible nitric oxide synthase (NOS) isoforms convert Arg to nitric oxide (NO), a potent vaso- and bronchodilator with multiple biological functions. Atopic dermatitis (AD) and bronchial asthma (BA) are atopic diseases affecting many children globally. Several studies analyzed NO in airways, yet the systemic synthesis of NO in AD and BA in children with BA, AD or both is elusive. Methods: In a multicenter study, blood and urine were obtained from 130 of 302 participating children for the measurement of metabolites of the Arg/NO pathway (BA 31.5%; AD 5.4%; AD + BA 36.1%; attention deficit hyperactivity disorder (ADHD) 12.3%). In plasma and urine amino acids Arg and homoarginine (hArg), both substrates of NOS, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), both inhibitors of NOS, dimethylamine (DMA), and nitrite and nitrate, were measured by gas chromatography–mass spectrometry. Malondialdehyde (MDA) was measured in plasma and urine samples to evaluate possible effects of oxidative stress. Results: There were no differences in the Arg/NO pathway between the groups of children with different atopic diseases. In comparison to children with ADHD, children with AD, BA or AD and BA had higher plasma nitrite (p < 0.001) and nitrate (p < 0.001) concentrations, suggesting higher systemic NO synthesis in AD and BA. Urinary excretion of DMA was also higher (p = 0.028) in AD and BA compared to patients with ADHD, suggesting elevated ADMA metabolization. Discussion/Conclusion: The Arg/NO pathway is activated in atopic diseases independent of severity. Systemic NO synthesis is increased in children with an atopic disease. Plasma and urinary MDA levels did not differ between the groups, suggesting no effect of oxidative stress on the Arg/NO pathway in atopic diseases.

Protein-Bound Uremic Toxins Induce Reactive Oxygen Species-Dependent and Inflammasome-Mediated IL-1β Production in Kidney Proximal Tubule Cells.

Protein bound-uremic toxins (PBUTs) are not efficiently removed by hemodialysis in chronic kidney disease (CKD) patients and their accumulation leads to various co-morbidities via cellular dysfunction, inflammation and oxidative stress. Moreover, it has been shown that increased intrarenal expression of the NLRP3 receptor and IL-1β are associated with reduced kidney function, suggesting a critical role for the NLRP3 inflammasome in CKD progression. Here, we evaluated the effect of PBUTs on inflammasome-mediated IL-1β production in vitro and in vivo. Exposure of human conditionally immortalized proximal tubule epithelial cells to indoxyl sulfate (IS) and a mixture of anionic PBUTs (UT mix) increased expression levels of NLRP3, caspase-1 and IL-1β, accompanied by a significant increase in IL-1β secretion and caspase-1 activity. Furthermore, IS and UT mix induced the production of intracellular reactive oxygen species, and caspase-1 activity and IL-1β secretion were reduced in the presence of antioxidant N-acetylcysteine. IS and UT mix also induced NF-κB activation as evidenced by p65 nuclear translocation and IL-1β production, which was counteracted by an IKK inhibitor. In vivo, using subtotal nephrectomy CKD rats, a significant increase in total plasma levels of IS and the PBUTs, kynurenic acid and hippuric acid, was found, as well as enhanced urinary malondialdehyde levels. CKD kidney tissue showed an increasing trend in expression of NLRP3 inflammasome components, and a decreasing trend in superoxide dismutase-1 levels. In conclusion, we showed that PBUTs induce inflammasome-mediated IL-1β production in proximal tubule cells via oxidative stress and NF-κB signaling, suggesting their involvement in disease-associated inflammatory processes.

Association of Particulate Matter from Cooking Oil Fumes with Heart Rate Variability and Oxidative Stress.

Many studies have reported various cardiovascular autonomic responses to ambient particulate matter (PM) pollution, but few have reported such responses to occupational PM exposures. Even fewer have demonstrated a relationship between PM pollution and oxidative stress in humans. This panel study evaluates the association between occupational exposure to PM in cooking oil fumes (COFs), and changes in both heart rate variability (HRV) and oxidative stress responses in 54 male Chinese cooks. Linear mixed-effects regression models were adopted to estimate the strength of the association between PM and HRV. Participants’ pre- and post-workshift urine samples were analyzed for 8-hydroxy-2′-deoxyguanosine (8-OHdG) and malondialdehyde (MDA). Exposure to PM in COFs from 15 min to 2 h were associated with a decrease in HRV and an increase in heart rate among cooks. The urinary 8-OHdG levels of cooks were significantly elevated after workshift exposure to COFs. The levels of PM2.5, PM1.0, and particulate benzo(a)pyrene in COFs were all positively correlated with cross-workshift urinary 8-OHdG levels. Furthermore, the levels of benzo(a)pyrene in COFs were positively correlated with cross-workshift urinary MDA levels. The effects of COFs on HRV were independent of cross-workshift urinary 8-OHdG levels. Exposure to COFs leads to disturbed autonomic function and an increased risk of oxidative DNA injury among cooks in Chinese restaurants.

The Interrelation of Environmental di-2-Ethylhexyl Phthalate (DEHP) and Melamine Exposure, Biomarkers of Oxidative Stress and Early Kidney Injury in Children and Adolescents Over Time-The 2011 Taiwan Food Scandal

Background: Exposure to di-(2-ethylhexyl) phthalate (DEHP)-tainted food from 2011 Taiwan food scandal increased children’s risk of microalbuminuria, possibly modified by melamine, was reported. This prospective cohort study is to investigate the temporal and interrelationship of exposure to DEHP-tainted foods, environmental DEHP exposure, and melamine, with markers of oxidative stress and renal injury over time. Methods: Children and adolescents possibly exposed to phthalate-tainted foodstuffs received surveys between August 2012 and October 2016 at first wave, second and third follow-up waves. Oxidative stress markers including malondialdehyde (MDA) and 8-oxo-2'-deoxyguanosine (8-OHdG), and renal injury markers including urine albumin/creatinine ratio (ACR) and N-acetyl-beta-D-glucosaminidase (NAG), were measured. Past DEHP exposure levels were categorized based on US EPA and European Food Safety Authority’s recommended tolerable daily intake levels, 20 and 50 μg/kg/day, respectively. Findings: Two hundred, 170, and 159 subjects were at the first, second, and third waves. General estimated equation modeling revealed significant main effects of past DEHP exposure and time on urinary ACR. When examining the temporal interaction of past DEHP exposure and time effect on urinary ACR, we found most of interaction variables were negative, but only the interaction of high past DEHP and second wave reached significant (P for interaction = 0.018). Current melamine exposure was significantly associated with urinary ACR, 8-OHdG, and MDA levels over time. Interpretation: DEHP-tainted food intake had its highest impact on increased urinary ACR at the beginning. This increase partially diminished over time. Environmental melamine exposure may increase urinary ACR and markers of oxidative stress over time. Funding: This work was financially supported by grants from Kaohsiung Medical University Hospital, (KMUH109-9R80); from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE), Kaohsiung Medical University Research Center Grant (KMU- TC109A01); from Ministry of Science and Technology (MOST109-2314-B-037- 066; 109-2314-B-037-072-; 107-2314-B-037-109-); from National Health Research Institutes ( NHRI-EX110-10703PI), all in Taiwan. None of these institutions played any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Declaration of Interest: All authors have declared that no competing interests exist. Ethical Approval: This study was dubbed the RAPIT cohort and was approved by the Institutional Review Boards (IRBs) of NHRI, MHWHs, and KMUH.

Urinary Malondialdehyde as a Biomarker of Type 2 Diabetes Mellitus Treatment in the Primary Care Unit of a Tertiary Care Hospital.

Introduction/ObjectivesThe examination of Urinary Malondialdehyde (UMDA) as a biomarker in the involvement of inflammatory response and oxidative stress, as a mechanism underlying the development of diabetes; in addition to complications in followed-up patients at a primary healthcare unit. The level of UMDA and its related factors in T2DM patients, between good and poor glycemic control was investigated.MethodsThis analytical cross-sectional study was conducted at the primary care unit, of Songklanagarind Hospital; from May 2020 to August 2020. The voluntary patients were divided into 2 groups, by using a percentage of HbA1c ≤7% as a good control T2DM group, and higher than 7% as a poor control T2DM group. The comparison statistics and logistic regression analysis were performed by using R Program.ResultsA total of 71 patients voluntarily participated in this study, and consisted of: 38 patients with poor glycemic control and 33 patients with good glycemic control. There were no significant differences between the patients; with the exception of smoking habits. The average levels of UMDA of the good control group (2.43 ± 0.91 μg/mL) were slightly lower than the poor control group (2.60 ± 0.96 μg/mL): P-value >.05. Patients who had underlying diseases, smoking, or drinking habits displayed significantly different levels of UMDA. Being a non-smoking patients, and having a higher level of HDL-C with significant protective factors, while having increased level of FBS and triglyceride were pointedly negative factors of oxidative stress status.ConclusionPatients who had good control of T2DM produced better health outcomes than the poor control group. UMDA, FBS, HDL-C, and triglyceride levels could be applied as follow-up criteria in T2DM patients within a primary healthcare setting.

Ambient particulate matter compositions and increased oxidative stress: Exposure-response analysis among high-level exposed population

BackgroundOxidative stress has been suggested to be one of the key drivers of health impact of particulate matter (PM). More studies on the oxidative potential of PM alone, but fewer studies have comprehensively evaluated the effects of external and internal exposure to PM compositions on oxidative stress in population. ObjectiveTo comprehensively investigate the exposure–response relationship between PM and its main compositions with oxidative stress indicators. MethodsWe conducted a cross-sectional study including 768 participants exposed to particulates. Environmental levels of fine particulate matter (PM2.5), polycyclic aromatic hydrocarbons (PAHs) and metals in PM were measured, and urinary levels of PAHs metabolites and metals were measured as internal dose, respectively. Multivariable linear regression models were used to analyze the correlations of PM exposure and urinary levels of 8-hydroxy-2́′-deoxyguanosine (8-OHdG), and 8-iso-prostaglandin-F2α (8-iso-PGF2α) and malondialdehyde (MDA). ResultsThe concentration of both PM2.5 and total PAHs was significantly correlated with increased urinary 8-OHdG, 8-iso-PGF2α and MDA levels (all p < 0.05). The levels of 4 essential metals all showed significant exposure–response increase in urinary 8-OHdG in both current and non-current smokers (all p < 0.05); ambient selenium, cobalt and zinc were found to be significantly correlated with urinary 8-iso-PGF2α (p = 0.002, 0.003, 0.01, respectively); only selenium and cobalt were significantly correlated with urinary MDA (p < 0.001, 0.01, respectively). Furthermore, we found each one-unit increase in urinary total OH-PAHs generated a 0.32 increase in urinary 8-OHdG, a 0.22 increase in urinary 8-iso-PGF2α and a 0.19 increase in urinary MDA (all p < 0.001). Furthermore, it was found that the level of 12 urinary metals all showed significant and positive correlations with three oxidative stress biomarkers in all subjects (all p < 0.001). ConclusionsOur systematic molecular epidemiological study showed that particulate matter components could induce increased oxidative stress on DNA and lipid. It may be more important to monitor and control the harmful compositions in PM rather than overall particulate mass.

Effect of Occupational Exposure to Herbicides on Oxidative Stress in Sprayers.

BackgroundHerbicides such as glyphosate, paraquat, and 2,4-dichlorophenoxyacetic acid have been reported to cause adverse side effects through production of reactive oxygen species. However, there were no data representing the adverse effects of a mixture herbicide usage in farmers, especially the changes in oxidative marker and antioxidant defense. This study aimed to determine the urinary malondialdehyde (MDA) and glutathione (GSH) level in farmers using mixed herbicides.MethodsNinety-three farmers were recruited, and two spot urine samples (before and after work) were collected. The urinary MDA level was evaluated by thiobarbituric acid reactive substance assay, and the urinary GSH level was determined using the enzymatic recycling method.ResultsSixty-two percent of the participants were men, and 59% of the participants worked in a farm for 20–40 years. The common combinations of herbicide usage were glyphosate with 2,4-dichlorophenoxyacetic acid (36.5%). There was no significant difference between pre- and post-work urinary MDA and GSH levels among the 3 groups of herbicides. However, the urinary MDA levels in farmers using the combination of glyphosate and paraquat were significantly higher than those found in farmers using glyphosate alone. The associated factors with changes in MDA levels found that the exposure intensity index (B = 0.154), the cumulative exposure intensity index (B = 0.023), and wearing gloves while working (B = −2.347) were found to be significantly associated with MDA level.ConclusionThe results suggest that the combined use of glyphosate and paraquat caused a significant increase in urinary MDA levels. Moreover, intensity of exposure to herbicide and wearing gloves were associated with the level of MDA.

Effect of particulate matter 2.5 exposure to urinary malondialdehyde levels of public transport drivers in Jakarta.

Background People who work long hours on the road are intensively exposed to high levels of fine particulate matters (PM2.5) which may lead to oxidative stress mechanisms in the human body that cause deleterious health problems. Malondialdehyde (MDA) is the major metabolite produced during lipid peroxidation metabolism that serves as a reliable biomarker for oxidative stress in cells. Objectives To identify the association between PM2.5 exposure and other characteristics with urinary MDA levels among public transport drivers in Jakarta. Methods A cross-sectional design was implemented by involving 130 public transport drivers of nine trajectories from Kampung Melayu Terminal, Jakarta. The continuous PM2.5 data were collected in personal measurement during one round trip of driving. Weight and height measurements were obtained to calculate body mass index (BMI) and structured questionnaires were completed to identify other characteristics. MDA levels were examined from the driver's urine right after driving and evaluated using TBARS analysis. Results The average of PM2.5 exposure was 91.56±20.05μg/m3 and MDA levels were 2.23±1.57nmoL/mL. Drivers with overweight and obese BMI had significantly higher MDA levels (2.66±1.65nmoL/mL) compared to those with normal and underweight BMI status (1.97±1.47nmoL/mL). Multiple linear regression analysis demonstrated low PM2.5 exposure, normal and underweight BMI status, and a long period of working as drivers were associated with MDA levels (p<0.05). Contrary to the prior study, PM2.5 exposure was negatively associated with MDA levels due to most drivers' BMI status being normal and underweight. Conclusion Our study suggests that the drivers who were obese and overweight should lose weight to lower the risk of increased MDA levels. We also suggest the drivers to consider maintaining their vehicle's ventilation system or using personal protection equipment (PPE) to avoid high PM2.5 exposure while driving.

LC-MS Quantification of Malondialdehyde-Dansylhydrazine Derivatives in Urine and Serum Samples.

We developed a robust analytical method for quantification of malondialdehyde (MDA) in urine and serum samples using dansylhydrazine (DH) as a derivatizing reagent. The derivatization procedure was partially carried out using an autosampler injection program to minimize errors associated with the low-volume addition of reagents and was optimized to yield a stable hydrazone derivative of MDA and its labeled d2-MDA analogue. The target MDA-DH derivatives were separated on an Agilent Zorbax Eclipse Plus Phenyl-Hexyl (3.0×100mm, 3.5μm) column. The mass-to-charge ratios of the target derivatives [(M+H)+ of 302 and 304 for MDA-DH and d2-MDA-DH, respectively] were analyzed in single ion monitoring mode using a single quadrupole mass spectrometer operated under positive electrospray ionization. The method limits of quantification were 5.63nM (or 0.405ng/mL) for urine analysis and 5.68nM (or 0.409ng/mL) for serum analysis. The quantification range for urine analysis was 5.63-500nM (0.405-36.0ng/mL) while the quantification range for serum analysis was 5.68-341nM (0.409-24.6ng/mL). The method showed good relative recoveries (98-103%), good accuracies (92-98%), and acceptable precisions (relative standard deviations 1.8-7.3% for inter-day precision; 1.8-6.1% for intra-day precision) as observed from the repeat analysis of quality control samples prepared at different concentrations. The method was used to measure MDA in individual urine samples (n=287) and de-identified archived serum samples (n=22) to assess the overall performance of the method. The results demonstrated that our method is capable of measuring urinary and serum levels of MDA, allowing its future application in epidemiologic investigations.

Copper\u2013zinc imbalance induces kidney tubule damage and oxidative stress in a population exposed to chronic environmental cadmium

PurposeThis cross-sectional study aimed to assess the effect of environmental cadmium (Cd) exposure and essential metal imbalance on renal tubular damage and oxidative stress in 979 adults living in a Cd-polluted area near an abandoned copper (Cu) refinery.MethodsWe analyzed urinary Cd concentrations, renal tubular damage and oxidative stress markers, such as beta-2 microglobulin (β2-MG) and N-acetyl-β-d-glucosaminidase (NAG) activity and urine malondialdehyde (MDA) levels. The serum copper-to-zinc ratio (CZR) was used as an essential metal imbalance indicator. We divided the subjects into two Cd exposure groups based on the reference level of urinary Cd for renal dysfunction (2 μg/g creatinine).ResultsThe geometric mean concentration of urinary Cd in all subjects was 2.25 μg/g creatinine. In both low and high Cd exposure groups, urinary Cd levels were positively correlated with urinary NAG activity, but not with serum CZR. After multivariate adjustment, serum CZR was strongly associated with urinary β2-MG levels in the low Cd exposure group (β = 1.360, P = 0.019) and was significantly associated with urinary MDA levels, regardless of Cd exposure level. In addition, the risk of renal tubular damage was significantly associated with urinary Cd level, particularly in the lowest or highest CZR tertile groups.ConclusionsEssential metal imbalance may be a determinant of oxidative stress and renal tubular damage in a chronically Cd-exposed population, and proper zinc supplementation will be effective in preventing adverse health effects due to Cd exposure.

Investigation of Blood and Urine Malondialdehyde Levels in Mice Exposed to Silica Dust

Background and Objectives:Occupational exposure to silica dust can lead to biochemical damage. Malondialdehyde (MDA) can be considered as a primary marker for measuring the level of oxidative stress in a living organism. This study was conducted in order to evaluate the level of MDA in blood and urine of mice exposed to silica dust.Material and Methods:In this experimental study, 72 mice (BALB/c) were randomly allocated to five exposed groups and 1 control group. Exposure of mice to pure 99% silica dust was done in closed containers. Blood sampling was performed from the heart of mice and urine sampling fulfilled by insertion into a metabolic cage. The RAOet al. method was used to measure MDA.Results:The highest level of plasma MDA in group 1 in the 4thmonth was 8.4±0.41 nmol/l and the lowest level of MDA was 1.3±0.2 nmol/l in the third sampling in the control group, also the highest amount of urine MDA in the first and second groups and 4 months after exposure was 1.16±0.51 nmol/l, and the lowest in the control group and in the third sampling was 0.48±0.06 nmol/l. A significant difference was found between the levels of MDA in all exposed groups at different times except for the 5thgroup with the lowest concentration (P&lt; 0.05).Conclusion:MDA in blood and urine could be proposed as a good biomarker for the evaluation of biochemical damages caused by silica dust. Measuring MDA is also a simple and inexpensive method that does not require complex equipment and can be used as an early detection test for biochemical damages caused by silica.

Pinitol consumption improves liver health status by reducing oxidative stress and fatty acid accumulation in subjects with non-alcoholic fatty liver disease: A randomized, double-blind, placebo-controlled trial

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent cause of chronic hepatic injury in the world. One of the most important therapeutic strategies for this disease is modulating oxidative stress. This study hypothesized that supplementation of pinitol might exert hepatic protective effects, by modulating oxidative stress in subjects with NAFLD. A randomized, double-blind controlled trial was conducted in 90 subjects with ultrasonography-proven NAFLD, who were randomly assigned to the placebo, low-dose (300 mg/d), or high-dose (500 mg/d) of pinitol for 12 weeks. The outcome measures were liver fat content, liver enzymes, fasting and postprandial lipids, and oxidative stress levels. To understand the underlying mechanism, plasma metabolomic analysis based on a gas chromatography/time-of-flight mass spectrometry and urinary pinitol analysis were also performed. The pinitol group showed significantly lower levels in liver fat content, plasma liver enzymes, fasting/postprandial urinary malondialdehyde levels, and postprandial triglycerides concentrations, but significantly higher in glutathione peroxidase level compared with the placebo group. The metabolomic analysis identified 27 differential metabolites involved in glycine/serine/threonine metabolism, alanine/aspartate/glutamate metabolism, D-glutamine/D-glutamate metabolism, and fatty acid synthesis, implicating the role of pinitol in glutathione-related lipid and energy metabolism. These results suggest that pinitol may exert modulatory effects upon energy and metabolic pathways by reducing oxidative stress and fatty acid accumulation, which can lead to hepatoprotective benefits in NAFLD subjects.

By-products of lithotripsy: Are they related to abdominal fat and wave characteristics?

ObjectivesThis study aimed to evaluate the correlations between by-products of extracorporeal shock wave lithotripsy (ESWL) and some physical parameters such as abdominal fat, energy levels, and shock wave pulses.MethodsA total of 40 patients (20 men and 20 women), aged 37.18 ± 10.64 years, with renal or ureteral stones were recruited. All patients were treated with ESWL, and their abdominal fat was measured using an Omron body fat monitor and the body mass index (BMI). Parameters such as the levels of malondialdehyde (MDA), ketones, and protein in urine were measured before and after ESWL using a Bio Doctor Analyzer. The wave characteristics of the lithotripsy procedure and the wave pulses were determined.ResultsThe mean levels of urinary MDA and ketones showed statistically significant increases in post-ESWL compared with pre-ESWL values. The results showed significant elevations in MDA and ketones in both male and female patients. In addition, there was a significant correlation between MDA/ketones and energy levels and between ketones and BMI in female patients. The analysis also revealed that the shock wave pulse had an insignificant impact on the by-product parameters.ConclusionAn energy level of ≤4 J is recommended for overweight and obese patients undergoing ESWL. In addition, measurement of the post-ESWL MDA urinary level should be performed as a routine test, especially in obese male patients.

Effect of a Protein Supplement on the Gut Microbiota of Endurance Athletes: A Randomized, Controlled, Double-Blind Pilot Study.

Nutritional supplements are popular among athletes to improve performance and physical recovery. Protein supplements fulfill this function by improving performance and increasing muscle mass; however, their effect on other organs or systems is less well known. Diet alterations can induce gut microbiota imbalance, with beneficial or deleterious consequences for the host. To test this, we performed a randomized pilot study in cross-country runners whose diets were complemented with a protein supplement (whey isolate and beef hydrolysate) (n = 12) or maltodextrin (control) (n = 12) for 10 weeks. Microbiota, water content, pH, ammonia, and short-chain fatty acids (SCFAs) were analyzed in fecal samples, whereas malondialdehyde levels (oxidative stress marker) were determined in plasma and urine. Fecal pH, water content, ammonia, and SCFA concentrations did not change, indicating that protein supplementation did not increase the presence of these fermentation-derived metabolites. Similarly, it had no impact on plasma or urine malondialdehyde levels; however, it increased the abundance of the Bacteroidetes phylum and decreased the presence of health-related taxa including Roseburia, Blautia, and Bifidobacterium longum. Thus, long-term protein supplementation may have a negative impact on gut microbiota. Further research is needed to establish the impact of protein supplements on gut microbiota.