Comparison of urinary and plasma malondialdehyde in preterm infants

Apex carnivores coping with metal(loid) pollution and oxidative stress: Biological and environmental drivers of variation in kidney of European brown bear

Induction of oxidative stress and the associated lipid peroxidation is a prevalent mechanism through which certain metal(loid)s exert nephrotoxic effects in mammals. Research on the toxic impacts of metal(loid)s in free-ranging large mammals at high trophic positions is exceedingly rare, yet crucial for understanding environmental exposure scenarios relevant to both human and animal risk assessment. Renal cortex tissues (N = 457) of free-ranging brown bears (Ursus arctos) from the Dinara-Pindos population sampled in Croatia were analysed herein for toxic metal(loid)s and the underlying biological and environmental drivers of variation, with their time trend monitored during the 2009-2022 period. In 28 individuals from the 2021-2022 period, we additionally investigated associations between metal(loid)s and oxidative stress and damage biomarkers in renal cortex cells. The principal generalized linear models used to approximate variations in biomarkers of oxidative stress and damage included non-essential As, Cd, Pb, Tl and U, and essential Co, Cu, Fe and Zn. Age class and season of sampling had no impact on biomarker levels, except for lipid peroxidation, LP (April ↑). Age, sex (females ↑), body condition index (↓) and season of sampling significantly influenced metal(loid)s levels. Non-specific mammalian thresholds were crossed for Cd and Pb toxicity in 1-16% and 2% of population, respectively. Renal levels of metal(loid)s did not exhibit a clear trend over the 13-year period. The levels found in this study were higher than in sympatric carnivorous and herbivorous species, but in line with findings in ursids worldwide. Potential adverse health effects from environmental exposure in brown bears may arise from disruption of oxidative balance, as evidence clearly indicated associated changes in catalase activity (↑), glutathione content (↑), LP (↓), reactive oxygen species (↓), total antioxidant capacity (↑) in the renal cortex due to the presence of the most toxicologically relevant Cd and Pb.

Paraoxonase and arylesterase activity of paraoxonase 1 and oxidative stress parameters in cervical intraepithelial neoplasia

Introduction

Paraoxonase 1 (PON1) is the enzyme that removes carcinogenic radicals from lipids. The aim of the study was to investigate the differences in PON1 activity and oxidation stress parameters between patients with cervical intraepithelial neoplasia (CIN) and healthy controls.

Materials and methods

The study included 65 women with CIN and 109 healthy women. Lipid parameters were determined on Cobas Integra 400 plus (Roche, Mannheim, Germany). Tiols and reduced glutathione (GSH) were determined spectrophotometric using Eliman reagent. Activity of PON1 was assessed with two substrates, paraoxon and phenylacetate by spectrophotometric method. Malondialdehyde (MDA) was determined by high performance liquid chromatography (Shimadzu Corporation, Kyoto, Japan). Mann-Whitney-test, t-test, χ2-test, correlation and logistic regression was used in statistical analysis. P < 0.05 was considered statistically significant.

Results

The basal (P = 0.929) and NaCl-stimulated (P = 0.985) PON1 activity and activities standardised on the concentration of high-density lipoprotein (HDL; P = 0.076; P = 0.065, respectively) and apolipoprotein AI (apo AI; P = 0.444; P = 0.499, respectively) as well as PON1 phenotypes (P = 0.842) did not differ significantly between the groups. The PON1 arylesterase activity (53±19 kU/L vs. 77±17 kU/L; P < 0.001) and HDL-standardized activity (37 (28-44) kU/mmol vs. 43 (37-50) kU/mmol; P < 0.001) and apoAI (29±11 kU/g vs. 44±11 kU/g; P < 0.001) was significantly reduced in the CIN group. The concentration of the thiol groups was similar (P = 0.519), of MDA was lower (0.39 (0.27-0.55) µmol/L vs. 0.76 (0.57-1.15) µmol/L; P < 0.001) and of GSH was higher (112.0 (66.0-129.6) µg/mL vs. 53.4 (34.8-134.4) µg/mL; P < 0.001) in the CIN group.

Conclusion

Reduced PON1 arylesterase activity, lower MDA and higher GSH concentration were observed in CIN patients.

Effect of Alpha Lipoic Acid Supplementation on Oxidative Stress and Lipid Parameters in Women Diagnosed with Low-Grade Squamous Intraepithelial Lesions (LSILs): A Double-Blind, Randomized, Placebo-Controlled Trial

Limited scientific evidence shows that alpha lipoic acid (ALA) can induce regression rates of low-grade squamous intraepithelial lesions (LSILs), but the mechanisms of these effects have not been elucidated. To gain a broader insight into its therapeutic potential and mechanisms of action, the effects of 3 months of supplementation with 600 mg of ALA on antioxidant and lipid status parameters in 100 patients with LSILs were investigated in a randomized, placebo-controlled study. The obtained results are discussed in terms of patients' initial metabolic status and diet quality (particularly nutritional intake of antioxidants). The obtained results showed that oxidative status biomarkers were not significantly affected by ALA supplementation. However, serum superoxide dismutase (SOD) activity was positively affected in the subgroup of patients with higher dietary antioxidant intake. Surprisingly, ALA supplementation resulted in a small but statistically significant increase in serum low density lipoprotein (LDL), and the observed effect was significantly affected by the initial lipid status of the participants. Larger studies are necessary to gain additional insights on the clinical significance of ALA as an antioxidant and hypolipemic agent and to optimize its potential application in LSIL treatment.

The effects of simvastatin and fenofibrate on malondialdehyde and reduced glutathione concentrations in the plasma, liver, and brain of normolipidaemic and hyperlipidaemic rats

The objective of study was to investigate the effects of different doses of simvastatin and fenofibrate on malondialdehyde (MDA) and reduced glutathione (GSH) in the plasma, liver, and brain tissue of male normolipidaemic and hyperlipidaemic rats. Normolipidaemic (Wistar) rats were receiving 10 or 50 mg/kg a day of simvastatin or 30 or 50 mg/kg a day of fenofibrate. Hyperlipidaemic (Zucker) rats were receiving 50 mg/kg/day of simvastatin or 30 mg/kg/day of fenofibrate. Control normolipidaemic and hyperlipidaemic rats were receiving saline. Simvastatin, fenofibrate, and saline were administered by gavage for three weeks. In normolipidaemic rats simvastatin and fenofibrate showed similar and dose-independent effects on plasma and brain MDA and GSH concentrations. Generally, plasma and brain MDA decreased, while brain GSH concentration increased. In hyperlipidaemic rats simvastatin did not affect plasma and brain MDA and GSH concentrations but significantly decreased liver GSH. Fenofibrate decreased plasma and liver MDA but increased brain MDA. In both rat strains fenofibrate significantly decreased liver GSH concentrations, most likely because fenofibrate metabolites bind to GSH. Our findings suggest that simvastatin acts as an antioxidant only in normolipidaemic rats, whereas fenofibrate acts as an antioxidant in both rat strains.

Evaluation of Toxic Effects Induced by Sub-Acute Exposure to Low Doses of α-Cypermethrin in Adult Male Rats

To contribute new information to the pyrethroid pesticide α-cypermethrin toxicity profile, we evaluated its effects after oral administration to Wistar rats at daily doses of 2.186, 0.015, 0.157, and 0.786 mg/kg bw for 28 days. Evaluations were performed using markers of oxidative stress, cholinesterase (ChE) activities, and levels of primary DNA damage in plasma/whole blood and liver, kidney, and brain tissue. Consecutive exposure to α-cypermethrin affected the kidney, liver, and brain weight of rats. A significant increase in concentration of the thiobarbituric acid reactive species was observed in the brain, accompanied by a significant increase in glutathione peroxidase (GPx) activity. An increase in GPx activity was also observed in the liver of all α-cypermethrin-treated groups, while GPx activity in the blood was significantly lower than in controls. A decrease in ChE activities was observed in the kidney and liver. Treatment with α-cypermethrin induced DNA damage in the studied cell types at almost all of the applied doses, indicating the highest susceptibility in the brain. The present study showed that, even at very low doses, exposure to α-cypermethrin exerts genotoxic effects and sets in motion the antioxidative mechanisms of cell defense, indicating the potential hazards posed by this insecticide.

Long-term effects of melatonin and resveratrol on aging rats: A multi-biomarker approach

Aging-related impaired body structure and functions may be, at least partially, caused by elevated oxidative stress. Melatonin (MEL) and resveratrol (RSV) may act as antioxidant and anti-aging compounds, but these actions in experimental animals and humans are controversial. Herein, a rat model of aging was used to study the long-term sex-related effects of MEL and RSV treatment on body mass and blood/plasma parameters of DNA damage, oxidative status (glutathione and malondialdehyde levels), and concentrations of sex hormones. Starting from the age of 3mo, for the next 9mo or 21mo male and female Wistar rats (n = 4-7 per group) were given water to drink (controls) or 0.1 % ethanol in water (vehicle), or MEL or RSV (each 10 mg/L vehicle). DNA damage in whole blood cells was tested by comet assay, whereas in plasma, glutathione, malondialdehyde, and sex hormones were determined by established methods. Using statistical analysis of data by ANOVA/Scheffe post hoc, we observed a similar sex- and aging-dependent rise of body mass in both sexes and drop of plasma testosterone in control and vehicle-treated male rats, whose pattern remained unaffected by MEL and RSV treatment. Compared with controls, all other parameters remained largely unchanged in aging and differently treated male and female rats. We concluded that the sex- and aging-related pattern of growth and various blood parameters in rats were not affected by the long-term treatment with MEL and RSV at the estimated daily doses (300-400 μg/kg b.m.) that exceed usual moderate consumption in humans.

Assessment of Educational Intervention Effects on the Level of Oxidative Stress Parameters and Performance in Oncology Staff

Background: Occupational exposure to antineoplastic drugs causes the production of free radicals and their reaction with macromolecules in the body. Objectives: The present study was conducted to evaluate the effectiveness of the educational intervention by using urinary oxidative stress indices of the oncology staff in Iranian hospitals. Methods: Healthy full-time oncology and pharmacy staff (n = 45) participated in this prospective interventional study. The training of the personnel for proper handling of the antineoplastic drugs was given. During their work shift, their performance was recorded in a checklist. Urinary oxidative stress indices of the staff and scores of their performances were obtained before and after their training. Results: The mean performance score of all oncology staff was statistically higher than after 2 months of educational intervention (P < 0.001). The mean activity levels of Superoxide Dismutase and Catalase enzymes of all oncology staff was statistically lower than after 2 months of educational intervention (P < 0.001). The mean level of Malondialdehyde of all oncology staff was statistically lower than after 2 months of educational intervention (P < 0.05). Conclusions: Educational intervention increased oncology staff performance score and it affected the level of the oxidative stress parameters 2 months after the educational intervention by decreasing the activity of enzymes and the level of malondialdehyde.

Assessment of transplacental and lactational genotoxicity of tembotrione in Wistar rats at different developmental stages by alkaline comet assay

This paper assessed the potential of trans-placental and -lactational genotoxicity and oxidative stress induction of tembotrione, a naturally derived allelopathic herbicide. Several treatment protocols were applied to measure primary DNA damage by alkaline comet assay in leucocytes and liver. To address the oxidative stress induction, TBARS, ROS, SOD, CA, GSH-Px activity were recorded. The dams were treated from the first gestation day and pups sacrificed after birth. The second treatment protocol comprised treating the dams during gestation and lactation and sacrificing the pups at weaning. The third group of pups comprised offspring of dams that were treated in gestation and lactation and sacrificed in puberty. To address translactational genotoxicity, dams were treated in lactation only. Dams treated in gestation and lactation were sacrificed after reentering the estrous cycle and analyzed for DNA damage and oxidative stress. Tembotrione doses encountered in everyday human exposure, as estimated by the EFSA, were applied in dam treatment in consecutive days (ADI: 0.0004 mg/kg b.w./day, AOEL: 0.0007 mg/kg b.w./day, 1/500 LD₅₀ 4.0 mg/kg b.w./day). Although we observed mitigated DNA integrity at the dose of 4.0 mg/kg/b.w./day in female pubertal rats, we can conclude that at the conditions employed in the study low doses of tembotrione do not pose a risk for DNA damage of the offspring of treated dams. Contrary to this, the highest dose significantly affected all the oxidative stress parameters in the liver and plasma of pubertal females, CAT and GSH-Px in the liver of males and ROS and CAT of dams.

Effects of low-level imidacloprid oral exposure on cholinesterase activity, oxidative stress responses, and primary DNA damage in the blood and brain of male Wistar rats

Imidacloprid is a neonicotinoid insecticide that acts selectively as an agonist on insect nicotinic acetylcholine receptors. It is used for crop protection worldwide, as well as for non-agricultural uses. Imidacloprid systemic accumulation in food is an important source of imidacloprid exposure. Due to the undisputable need for investigations of imidacloprid toxicity in non-target species, we evaluated the effects of a 28-day oral exposure to low doses of imidacloprid (0.06 mg/kg b. w./day, 0.8 mg/kg b. w./day and 2.25 mg/kg b. w./day) on cholinesterase activity, oxidative stress responses and primary DNA damage in the blood and brain tissue of male Wistar rats. Exposure to imidacloprid did not cause significant changes in total cholinesterase, acetylcholinesterase and butyrylcholinesterase activities in plasma and brain tissue. Reactive oxygen species levels and lipid peroxidation increased significantly in the plasma of rats treated with the lowest dose of imidacloprid. Activities of glutathione-peroxidase in plasma and brain and superoxide dismutase in erythrocytes increased significantly at the highest applied dose. High performance liquid chromatography with UV diode array detector revealed the presence of imidacloprid in the plasma of all the treated animals and in the brain of the animals treated with the two higher doses. The alkaline comet assay results showed significant peripheral blood leukocyte damage at the lowest dose of imidacloprid and dose-dependent brain cell DNA damage. Oral 28-day exposure to low doses of imidacloprid in rats resulted in detectable levels of imidacloprid in plasma and brain tissue that directly induced DNA damage, particularly in brain tissue, with slight changes in plasma oxidative stress parameters.

Evaluation of oxidative stress responses and primary DNA damage in blood and brain of rats exposed to low levels of tembotrione

Tembotrione is a rather novel pesticide, usually used for post-emergence weed control. Even though its use is rapidly growing, it is not followed by an adequate flow of scientific evidence regarding its toxicity towards non-target organisms. We evaluated the potential of low doses of tembotrione to induce oxidative stress and cytogenetic damage in blood and brain cells of adult male Wistar rats. Parameters of lipid peroxidation, glutathione levels, activities of antioxidant enzymes and primary DNA damage were assessed following 28-day repeated oral exposure to doses comparable with the currently proposed health-based reference values. The results of the alkaline comet assay showed that such low doses of tembotrione have the potency to inflict primary DNA damage in both peripheral blood leukocytes and brain of treated rats, even with only slight changes in the oxidative biomarker levels. The DNA damage in blood and brain cells of Wistar rats significantly increased at all applied doses, suggesting that tembotrione genotoxicity is mainly a result of direct interaction with DNA while the induction of oxidative stress responses contributes to DNA instability in a lesser extent. The findings of the present study call for further research using other sensitive biomarkers of effect and different exposure scenarios.

Association of Uric Acid in Serum and Urine with Arterial Stiffness: Hanzhong Adolescent Hypertension Study

Background

Hyperuricemia has long been associated with increased cardiovascular risk, and arterial stiffness is proposed as a mediator. The present study is aimed at examining the associations of uric acid (UA) in blood and urine with arterial stiffness in a Chinese cohort.

Methods

A total of 2296 participants (mean age: 43.0 years) from our previously established cohort of Hanzhong Adolescent Hypertension Study were included. The participants were classified as subjects with or without arterial stiffness, which was defined as brachial-ankle pulse wave velocity (baPWV) ≥ 1400 cm/s and/or carotid intima-media thickness (CIMT) ≥ 0.9 mm. Multivariate regression analyses were used to examine the relationship between serum and urinary UA and the risk of arterial stiffness after adjusting for age, gender, systolic blood pressure, fasting glucose, BMI, heart rate, total cholesterol, and triglycerides.

Results

baPWV was positively correlated with urinary uric acid/creatinine ratio (uUA/Cre) (β = 0.061, P < 0.001), while CIMT was correlated with uUA/Cre (β = 0.085, P < 0.001) and fractional excretion of uric acid (FEUA) (β = 0.044, P = 0.033) in all subjects. In addition, uUA/Cre was significantly associated with the risk of high baPWV [1.032 (1.019-1.045)] and arterial stiffness [1.028 (1.016-1.040)].

Conclusion

Our study showed that urinary UA excretion was significantly associated with the risk of arterial stiffness in Chinese adults. These findings suggest that UA, especially urinary UA, may be used as a simple, noninvasive marker for early detection of arterial stiffness in otherwise healthy subjects.

Metal(loid) exposure assessment and biomarker responses in captive and free-ranging European brown bear (Ursus arctos)

We investigated the level of five non-essential metal(loid)s (As, Cd, Hg, Tl, Pb) and nine essential metals (Mg, Ca, Mn, Fe, Co, Cu, Zn, Se, Mo) in hair and blood components of captive and free-ranging European brown bear populations in Croatia and Poland. Metal(loid) associations with biomarkers of oxidative stress (superoxide dismutase, SOD; glutathione-peroxidase, GSH-Px; malondialdehyde, MDA) and metal exposure (metallothionein, MT) were estimated in this top predatory mammal. Lead was the most abundant non-essential metal(loid) in both blood and hair, with 4 of 35 individuals having blood levels over 100 μg/L. A positive association was found between Pb level and SOD activity in blood. Free-ranging bears had higher blood SOD activity, Mn, Zn and Cd levels, hair Co, Cd, Tl and Pb compared to captive individuals, while the opposite was true for Mg and hair Ca thereby reflecting habitat and diet differences. With increasing age, animals showed lower levels of SOD activity and certain essential metals. Females had higher SOD activity and blood levels of some essential metals than males. Hair showed a higher Fe and Co level when sampled during the growth phase and was not predictive of non-essential metal(loid) blood levels. The established metal(loid) baseline values will enable future risk assessment in both captive and wild European brown bear populations.

Sex-dependent expression of metallothioneins MT1 and MT2 and concentrations of trace elements in rat liver and kidney tissues: Effect of gonadectomy

Metallothioneins (MTs) exhibit binding affinity for several essential and toxic trace elements. Previous studies in rodents indicated sex differences in the hepatic and renal expression of MTs and concentrations of various elements. The mechanism responsible for these differences has not been resolved. Here, in the liver and kidney tissues of sham-operated and gonadectomized male and female rats we determined the expression of MT1 and MT2 (MT1&2) mRNA by RT-PCR, abundance of MT1&2 proteins by Western blotting and immunocytochemistry, concentrations of essential (Fe, Zn, Cu, Co) and toxic (Cd, Hg, Pb) elements by ICP-MS, and oxidative status parameters (SOD, GPx, MDA, GSH) by biochemical methods. In both organs, the expression of MT1&2 mRNA and MT1&2 proteins was female-dominant, upregulated by castration, and downregulated by ovariectomy. Concentrations of Fe in the liver and Co in the kidneys followed the same pattern. Most other elements (Zn, Cu, Cd, Hg) exhibited female- or male-dominant sex differences, affected by gonadectomy in one or both organs. Pb was sex- and gonadectomy-unaffected. GPx and MDA were elevated and associated with the highest concentrations of Fe only in the female liver. We conclude that the sex-dependent expression of MT1&2 mRNA and proteins in the rat liver and kidneys may include different mechanisms. In the liver, the female-dominant tissue concentrations of Fe may generate oxidative stress which is a potent enhancer of MTs production, whereas in kidneys, the female-dominant expression of MTs may be unrelated to Fe-mediated oxidative stress.

DNA Damaging Effects, Oxidative Stress Responses and Cholinesterase Activity in Blood and Brain of Wistar Rats Exposed to Δ9-Tetrahydrocannabinol

Currently we are faced with an ever-growing use of Δ9-tetrahydrocannabinol (THC) preparations, often used as supportive therapies for various malignancies and neurological disorders. As some of illegally distributed forms of such preparations, like cannabis oils and butane hash oil, might contain over 80% of THC, their consumers can become intoxicated or experience various detrimental effects. This fact motivated us for the assessments of THC toxicity in vivo on a Wistar rat model, at a daily oral dose of 7 mg/kg which is comparable to those found in illicit preparations. The main objective of the present study was to establish the magnitude and dynamics of DNA breakage associated with THC exposure in white blood and brain cells of treated rats using the alkaline comet assay. The extent of oxidative stress after acute 24 h exposure to THC was also determined as well as changes in activities of plasma and brain cholinesterases (ChE) in THC-treated and control rats. The DNA of brain cells was more prone to breakage after THC treatment compared to DNA in white blood cells. Even though DNA damage quantified by the alkaline comet assay is subject to repair, its elevated level detected in the brain cells of THC-treated rats was reason for concern. Since neurons do not proliferate, increased levels of DNA damage present threats to these cells in terms of both viability and genome stability, while inefficient DNA repair might lead to their progressive loss. The present study contributes to existing knowledge with evidence that acute exposure to a high THC dose led to low-level DNA damage in white blood cells and brain cells of rats and induced oxidative stress in brain, but did not disturb ChE activities.

Oxidative stress as a mechanism of combined OTA and CTN toxicity in rat plasma, liver and kidney

Ochratoxin A (OTA) and citrinin (CTN) commonly coexist in grains. Aiming to evaluate oxidative stress in OTA + CTN toxicity, male Wistar rats were orally treated with two doses of OTA (0.125 and 0.250 mg kg−1 of body weight (b.w.)), CTN (2 mg kg−1 of b.w.) and resveratrol (RSV; 20 mg kg−1 of b.w.) and combined daily during 3 weeks. Protein carbonyl concentrations were measured in kidneys and liver; catalytic activity of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) level in plasma, kidneys and liver, while malondialdehyde (MDA) concentration was measured in plasma, kidneys, liver and urine. Mycotoxin treatment significantly increased MDA concentration in plasma and kidney and decreased SOD activity in the liver. Rats treated with CTN and OTA125 + CTN had lower plasma GPx activity. Concentration of GSH in the kidney and protein carbonyls in the kidney and liver as well as GPx activity in the kidney and liver, SOD activity in the kidney and CAT activity in the liver were not affected. Protective effect of RSV was observed on GSH in the kidney and plasma and MDA in the kidney, plasma and urine. Oxidative stress is involved in OTA + CTN toxicity in vivo because such treatment affects parameters of oxidative stress, particularly in plasma. RSV can reduce but not overcome oxidative stress induced by combined OTA and CTN treatment.

Differential expression of heat shock proteins and activation of mitogen-activated protein kinases in A549 alveolar epithelial cells exposed to cigarette smoke extract

NEW FINDINGS

What is the central question of this study? What is the effect of cigarette smoke on cell death, oxidative damage, expression of heat shock proteins (HSPs) and activation of mitogen-activated protein kinases (MAPKs) in A549 alveolar epithelial cells? What is the main finding and its importance? Cigarette smoke induces cytotoxicity and oxidative damage to A549 cells, increases expression of different HSPs and activates MAPK signalling pathways. This could be related to inflammatory response and apoptosis observed in lungs of patients with smoking-related diseases.

ABSTRACT

Cigarette smoking is one of the main risk factors for development of chronic obstructive pulmonary disease (COPD). We previously reported that cigarette smoke (CS) induces damage to proteins and their ineffective degradation. Here, we hypothesize that CS could induce oxidative stress and cytotoxicity in lung epithelial cells through alterations of heat shock protein (HSP) expression and mitogen-activated protein kinase (MAPK) signalling pathways. We exposed A549 alveolar epithelial cells to various concentrations of cigarette smoke extract (CSE). Higher concentrations of CSE caused apoptosis of A549 cells after 4 h, while after 24 h cell viability was decreased, and lactate dehydrogenase in cell culture medium was increased as well as the number of necrotic cells. Concentrations of malondialdehyde (MDA) were elevated, while total thiol groups were decreased. Changes in the expression of HSPs (HSP70, HSP32 and HSP27) were time-dependent. After 6 h, CSE caused an increase in the expression of HSP70 and HSP32, while after 8 h all examined HSPs were up-regulated and remained increased up to 48 h. Treatment of A549 cells with CSE stimulated phosphorylation of extracellular signal-regulated kinase and p38 in a dose-dependent manner, while c-Jun N-terminal kinase activation was not detected. By using specific inhibitors, we demonstrated that MAPKs and HSPs interplay in CSE effects. In conclusion, our results show that MAPKs and HSPs are involved in the mechanism underlying CSE-induced cytotoxicity and oxidative damage to A549 alveolar epithelial cells. These processes could be related to inflammatory response and apoptosis observed in lungs of patients with smoking-related diseases, such as COPD.

Effects of the chloro-s-triazine herbicide terbuthylazine on DNA integrity in human and mouse cells

Terbuthylazine belongs to the chloro-s-triazine group of herbicides and acts primarily as a photosynthesis inhibitor. The mechanisms of action related to its exposure, relevant both in animals and humans, are still insufficiently investigated. This comprehensive study focused on the outcomes of terbuthylazine exposure at cell level in vitro, and a mice model in vivo. Experiments in vitro were conducted on whole human peripheral blood, isolated lymphocytes, and HepG2 cells exposed for 4 h to terbuthylazine at 8.00, 0.80, and 0.58 ng/mL, which is comparable with current reference values set by the European Commission in 2011. Terbuthylazine cytotoxicity was evaluated using dual fluorescent staining with ethidium bromide and acridine orange on lymphocytes, and CCK-8 colorimetric assay on HepG2 cells. The levels of DNA damage were measured using alkaline and hOGG1-modified comet assays. The potency of terbuthlyazine regarding induction of oxidative stress in vitro was studied using a battery of standard oxidative stress biomarkers. The in vivo experiment was conducted on Swiss albino mice exposed to terbuthlyazine in the form of an active substance and its formulated commercial product Radazin TZ-50 at a daily dose of 0.0035 mg/kg bw for 14 days. Following exposure, the DNA damage levels in leukocytes, bone marrow, liver, and kidney cells of the treated mice were measured using an alkaline comet assay. In vitro results suggested low terbuthylazine cytotoxicity in non-target cells. The highest tested concentration (8.00 ng/mL) reduced lymphocyte viability by 15%, mostly due to apoptosis, while cytotoxic effects in HepG2 cells at the same concentration were negligible. Acute in vitro exposure of human lymphocytes and HepG2 cells to terbuthylazine resulted in low-level DNA instability, as detected by the alkaline comet assay. Further characterization of the mechanisms behind the DNA damage obtained using the hOGG1-modified comet assay indicated that oxidative DNA damage did not prevail in the overall damage. This was further confirmed by the measured levels of oxidative stress markers, which were mostly comparable to control. Results obtained in mice indicate that both the active substance and formulated commercial product of terbuthylazine produced DNA instability in all of the studied cell types. We found that DNA in liver and kidney cells was more prone to direct toxic effects of the parent compound and its metabolites than DNA in leukocytes and bone marrow cells. The overall findings suggest the formation of reactive terbuthylazine metabolites capable of inducing DNA cross-links, which hinder DNA migration. These effects were most pronounced in liver cells in vivo and HepG2 cells in vitro. To provide a more accurate explanation of the observed effects, additional research is needed. Nevertheless, the present study provides evidence that terbuthylazine at concentrations comparable with current reference values possesses toxicological risk because it caused low-level DNA instability, both at cellular and animal organism level, which should be further established in forthcoming studies.

Irinotecan and Δ⁸-Tetrahydrocannabinol Interactions in Rat Liver: A Preliminary Evaluation Using Biochemical and Genotoxicity Markers

There is growing interest regarding the use of herbal preparations based on Cannabis sativa for medicinal purposes, despite the poorly understood interactions of their main constituent Δ⁸-tetrahydrocannabinol (THC) with conventional drugs, especially cytostatics. The objective of this pilot study was to prove whether the concomitant intake of THC impaired liver function in male Wistar rats treated with the anticancer drug irinotecan (IRI), and evaluate the toxic effects associated with this exposure. IRI was administered once intraperitoneally (at 100 mg/kg of the body weight (b.w.)), while THC was administered per os repeatedly for 1, 3, and 7 days (at 7 mg/kg b.w.). Functional liver impairments were studied using biochemical markers of liver function (aspartate aminotransferase-AST, alanine aminotransferase-ALP, alkaline phosphatase-AP, and bilirubin) in rats given a combined treatment, single IRI, single THC, and control groups. Using common oxidative stress biomarkers, along with measurement of primary DNA damage in hepatocytes, the degree of impairments caused at the cellular level was also evaluated. THC caused a time-dependent enhancement of acute toxicity in IRI-treated rats, which was confirmed by body and liver weight reduction. Although single THC affected ALP and AP levels more than single IRI, the levels of liver function markers measured after the administration of a combined treatment mostly did not significantly differ from control. Combined exposure led to increased oxidative stress responses in 3- and 7-day treatments, compared to single IRI. Single IRI caused the highest DNA damage at all timepoints. Continuous 7-day oral exposure to single THC caused an increased mean value of comet tail length compared to its shorter treatments. Concomitant intake of THC slightly affected the levels of IRI genotoxicity at all timepoints, but not in a consistent manner. Further studies are needed to prove our preliminary observations, clarify the underlying mechanisms behind IRI and THC interactions, and unambiguously confirm or reject the assumptions made herein.

Oxidative stress, cholinesterase activity, and DNA damage in the liver, whole blood, and plasma of Wistar rats following a 28-day exposure to glyphosate

In this 28 day-study, we evaluated the effects of herbicide glyphosate administered by gavage to Wistar rats at daily doses equivalent to 0.1 of the acceptable operator exposure level (AOEL), 0.5 of the consumer acceptable daily intake (ADI), 1.75 (corresponding to the chronic population-adjusted dose, cPAD), and 10 mg kg-1 body weight (bw) (corresponding to 100 times the AOEL). At the end of each treatment, the body and liver weights were measured and compared with their baseline values. DNA damage in leukocytes and liver tissue was estimated with the alkaline comet assay. Oxidative stress was evaluated using a battery of endpoints to establish lipid peroxidation via thiobarbituric reactive substances (TBARS) level, level of reactive oxygen species (ROS), glutathione (GSH) level, and the activity of glutathione peroxidase (GSH-Px). Total cholinesterase activity and the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were also measured. The exposed animals gained less weight than control. Treatment resulted in significantly higher primary DNA damage in the liver cells and leukocytes. Glyphosate exposure significantly lowered TBARS in the liver of the AOEL, ADI, and cPAD groups, and in plasma in the AOEL and cPAD group. AChE was inhibited with all treatments, but the AOEL and ADI groups significantly differed from control. Total ChE and plasma/liver ROS/GSH levels did not significantly differ from control, except for the 35 % decrease in ChE in the AOEL and ADI groups and a significant drop in liver GSH in the cPAD and 100xAOEL groups. AOEL and ADI blood GSH-Px activity dropped significantly, but in the liver it significantly increased in the ADI, cPAD, and 100xAOEL groups vs. control. All these findings show that even exposure to low glyphosate levels can have serious adverse effects and points to a need to change the approach to risk assessment of low-level chronic/sub-chronic glyphosate exposure, where oxidative stress is not necessarily related to the genetic damage and AChE inhibition.

Phytosterols on growth performance, antioxidant enzymes and intestinal morphology in weaned piglets

BACKGROUND

Plant extracts have been used widely to improve growth, lower cholesterol, and exert antioxidative defense and antimicrobial activities in animal production. The present study aimed to investigate the effects of dietary phytosterols (PS) on growth performance, antioxidant enzymes and intestinal morphology in weaned piglets.

RESULTS

A total of 120 crossbred piglets, weighing 9.58 ± 0.26 kg, were randomly allocated to three treatments: control, PS (0.2 g kg^-1 ) and polymyxin E (0.04 g kg^-1 , antibiotic control). Compared to the control, PS or polymyxin E supplementation decreased diarrhea rate, serum cholesterol and malondialdehyde (MDA) of the piglets (P < 0.05). Liver MDA was significantly decreased in PS-fed piglets compared to the control (P < 0.05), although there was no difference between the control and polymyxin E-fed piglets. PS increased the villous height/crypt depth ratio of the duodenum and jejunum compared to the control (P < 0.05). Polymyxin E supplementation in piglets did not alter the villous height/crypt depth ratio but raised the villous height and crypt depth of the duodenum compared to the control (P < 0.05).

CONCLUSION

The results of the present study indicated that PS could decrease diarrhea rate, lower serum cholesterol, reduce lipid peroxidation and ameliorate intestinal morphology in weaned piglets. In addition, PS exerted better amelioration on intestinal morphology than polymyxin E in piglets. © 2017 Society of Chemical Industry.

Serum and Urinary Malondialdehyde (MDA), Uric acid, and Protein as markers of perinatal asphyxia

INTRODUCTION

Perinatal asphyxia (PA) is among the leading causes of neonatal morbidity and death in neonatal intensive care units (NICUs). The aims of this research were to determine the concentrations of malondialdehyde (MDA), urine MDA, uric acid, and protein in the cord blood of neonates with perinatal asphyxia and to determine their relationship with the severity of perinatal asphyxia.

METHODS

This matched case-control study was conducted from October 2012 to March 2013. All of the cases and controls were selected from the Gynecology & Obstetrics Department and the NICUs, at Qous Central Hospital in Qena, Egypt. We allocated 20 full-term neonates who had perinatal asphyxia to the case group. Also, we selected 20 healthy neonates for the control group. The subjects were matched with respect to age and gender. At birth and 48 hours later, measurements were made of MDA in cord blood and urine, and uric acid, protein, and creatinine also were measured in both groups. The data were analyzed by SPSS, version 17, using the independent-samples t-test, ANOVA, Tukey's test, and Spearman's correlation coefficient.

RESULTS

At birth and 48 hr later, the newborns' with PA had significantly higher levels of MDA in the cord blood, mean urinary uric acid/creatinine (UUA:Cr), protein/creatinine (UP:Cr), and MDA/creatinine ratio (UMDA:Cr) than the controls; their PA levels were correlated with the degree of hypoxic-ischemic encephalopathy (HIE). The babies who died due to PA had significantly higher levels of cord blood MDA, and they also had higher UUA:Cr, UP:Cr, and UMDA:Cr ratios than the babies who survived.

CONCLUSION

The concentration of MDA in cord blood can be used as a diagnostic marker of oxidative stress in asphyxiated neonates. The ratios of the urinary excretion rates of uric acid, protein, and MDA to creatinine increased as the severity of perinatal asphyxia and associated brain damage increased.

In female rats, ethylene glycol treatment elevates protein expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) without inducing hyperoxaluria

Aim

To investigate whether the sex-dependent expression of hepatic and renal oxalate transporter sat-1 (Slc26a1) changes in a rat model of ethylene glycol (EG)-induced hyperoxaluria.

Methods

Rats were given tap water (12 males and 12 females; controls) or EG (12 males and 12 females; 0.75% v/v in tap water) for one month. Oxaluric state was confirmed by biochemical parameters in blood plasma, urine, and tissues. Expression of sat-1 and rate-limiting enzymes of oxalate synthesis, alcohol dehydrogenase 1 (Adh1) and hydroxy-acid oxidase 1 (Hao1), was determined by immunocytochemistry (protein) and/or real time reverse transcription polymerase chain reaction (mRNA).

Results

EG-treated males had significantly higher (in μmol/L; mean ± standard deviation) plasma (59.7 ± 27.2 vs 12.9 ± 4.1, P < 0.001) and urine (3716 ± 1726 vs 241 ± 204, P < 0.001) oxalate levels, and more abundant oxalate crystaluria than controls, while the liver and kidney sat-1 protein and mRNA expression did not differ significantly between these groups. EG-treated females, in comparison with controls had significantly higher (in μmol/L) serum oxalate levels (18.8 ± 2.9 vs 11.6 ± 4.9, P < 0.001), unchanged urine oxalate levels, low oxalate crystaluria, and significantly higher expression (in relative fluorescence units) of the liver (1.59 ± 0.61 vs 0.56 ± 0.39, P = 0.006) and kidney (1.77 ± 0.42 vs 0.69 ± 0.27, P < 0.001) sat-1 protein, but not mRNA. The mRNA expression of Adh1 was female-dominant and that of Hao1 male-dominant, but both were unaffected by EG treatment.

Conclusions

An increased expression of hepatic and renal oxalate transporting protein sat-1 in EG-treated female rats could protect from hyperoxaluria and oxalate urolithiasis.

In vivo evaluation of cholinesterase activity, oxidative stress markers, cyto- and genotoxicity of K048 oxime–a promising antidote against organophosphate poisoning

K048 is a member of K-oximes, a new oxime class that has recently been confirmed effective against poisoning by the nerve agent tabun and several pesticides. The toxicity profile of the K048 oxime has not been fully characterized and its optimal therapeutic dose has not yet been established. Earlier studies report excellent results with K048 in reactivating tabun-phosphorylated AChE and in the therapy of tabun-poisoned mice. It possesses a low acute toxicity and exerts an acceptable toxicity profile on isolated human peripheral blood lymphocytes in vitro. Intraperitoneal administration of K048 in rats resulted in an LD50 of 238.3 mg/kg. In this in vivo study, we investigated cholinesterase (ChE) activity and oxidative stress marker levels (lipid peroxidation and superoxide dismutase activity) in the plasma of exposed rats after administering the compound at 25% of its LD50. Lymphocyte viability was evaluated using an acridine orange/ethidium bromide in situ fluorescent assay. The levels of primary DNA damage in rat white blood cells were measured using the alkaline comet assay. The compound applied at 25% of its LD50 did not significantly affect ChE activity and lipid peroxidation and did not cause significant changes in the SOD activity in plasma. The cytotoxicity profile of K048 in the tested dose was also acceptable, and it did not possess significant DNA-damaging potential. The obtained results are promising for further evaluations of the K048 oxime, which should include tests on a broader concentration range and longer incubation times.

Plasma malondialdehyde levels in children on 12-hour cyclic parenteral nutrition: are there health risks?

In children undergoing total parenteral nutrition (PN), lipids provide a key source of calories preventing or correcting energy deficits and improving outcomes. However, some of these lipids may undergo oxidation leading to the formation of malondialdehyde (MDA), a cytotoxic byproduct found in these patients. This paper aims to describe a sensitive method for detecting MDA and discuss its role in certain diseases commonly found in children on regular PN. To quantify MDA levels in children benefitting from long-term cyclic PN, a reliable and sensitive high-performance liquid chromatographic method based on a 1-step derivatization/extraction procedure analysis with ultraviolet determination at 305 nm wavelength was achieved. In control children without PN, MDA levels were on average 3.30 ± 0.08 µM. However, in children nourished intravenously by fat emulsion for a long time, in which liver problems have been identified, the circulating concentrations of MDA ranged widely at both the start and the end of a session, 3- to 10-fold, respectively, in comparison with the levels measured in controls. This finding indicates that PN administrated long term raises plasma MDA levels, indicating chronic exposure and therefore a possible health risk, particularly liver damage. This preliminary study using a limited number of patients and controls showed that children undergoing long-term PN are strongly exposed to MDA, which must be considered as a potent toxic compound rather than a simple marker of lipid peroxidation.

Lipid peroxidation is essential for phospholipase C activity and the inositol-trisphosphate-related Ca²⁺ signal

Reactive oxygen species (ROS) are produced in enzymatic and non-enzymatic reactions and have important roles in cell signalling but also detrimental effects. ROS-induced damage has been implicated in a number of neurological diseases; however, antioxidant therapies targeting brain diseases have been unsuccessful. Such failure might be related to inhibition of ROS-induced signalling in the brain. Using direct kinetic measures of lipid peroxidation in astrocytes and measurements of lipid peroxidation products in brain tissue, we here show that phospholipase C (PLC) preferentially cleaves oxidised lipids. Because of this, an increase in the rate of lipid peroxidation leads to increased Ca(2+) release from endoplasmic reticulum (ER) stores in response to physiological activation of purinoreceptors with ATP. Both vitamin E and its water-soluble analogue Trolox, potent ROS scavengers, were able to suppress PLC activity, therefore dampening intracellular Ca(2+) signalling. This implies that antioxidants can compromise intracellular Ca(2+) signalling through inhibition of PLC, and that PLC plays a dual role - signalling and antioxidant defence.

Can urinary excretion rate of 8-isoprostrane and malonaldehyde predict postoperative cognitive dysfunction in aging?

Oxidative stress has been associated with mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, little is known about oxidative stress in postoperative cognitive dysfunction (POCD) in aging. The aim of this study was to investigate urinary excretion rate of 8-isoprostane:creatinine (U8-isoPG:Cr) and malonaldehyde:creatinine (UMDA:Cr) to predict short-term POCD in elderly patients undergoing general and orthopedic surgery. 72 patients aged above 65 years were enrolled in this prospective observational study. Each patient underwent cognitive testing to determine POCD performed by an investigator before surgery and 1 week after surgery. Morning urine was collected at baseline, 1, 2, and 7 days postoperatively. U8-isoPG was performed using enzymelinked immunosorbent assay (ELISA), and UMDA levels were measured by chemiluminescence detection. Creatinine levels were also analyzed if differences in the oxidative biomarkers were observed in the urine creatinine concentration. (1). Of 72 patients who completed cognitive testing, postoperative cognitive dysfunction was detected in 29.2 % (n = 21) of patients in 7 days. (2) U8-isoPG:Cr levels in 7 days postoperatively were significantly higher in POCD patients compared with the non-POCD group (p = 0.01). When measuring change from baseline, U8-isoPG:Cr levels were higher than that of control groups (p = 0.01). (3) UMDA:Cr levels were significantly elevated in 1 and 2 days postoperatively in both groups (p < 0.05). U8-isoPG:Cr level seems to be a valuable marker to detect lipid peroxidation early in POCD patients. However, it will also be important to take into account or reduce potential confounders to improve the identification of changes in the status of oxidative stress as a marker for POCD.

Malondialdehyde and heavy metal concentrations in tissues of wild boar (Sus scrofa L.) from central Croatia

The aim of this research was to assess the degree of heavy metal (cadmium, lead and mercury) contamination of wild boars from central Croatia and thereby conduct further tests to connect the contamination to oxidative stress occurrence. The highest cadmium concentration was noticed in the kidneys of older boars, the lead concentration was approximately the same in the liver and kidneys, but it was much higher than the concentration in the muscles, while the highest mercury concentration was measured in the kidneys of all wild boars. The correlation between the malondialdehyde (MDA) and the heavy metal concentrations was higher in tissue samples taken from younger animals (1 to 3 years of age) than in the tissue samples taken from older animals (5 to 6 years of age). In the kidneys of all wild boars there was a statistically significant connection between the MDA and cadmium concentration; in the kidneys of younger wild boars there was a statistically significant connection between the MDA and lead concentration. Further research on this topic should focus on MDA potential to find its use, not only as a contamination biomarker in the area of ecotoxicology, but also in the evaluation of the hygienic acceptability of animal products.

In vivo oxidative DNA damage and lipid peroxidation as a biomarker of oxidative stress in preterm low-birthweight infants

OBJECTIVES

To analyze the status of oxidative stress in relation to the degree of prematurity and birthweight of neonates.

MATERIALS AND METHODS

Umbilical cord blood samples were obtained at the time of delivery. 8-Hydroxy-2-deoxy guanosine (8-OHdG) has been measured as oxidative DNA damage marker in preterm low-birthweight (LBW) newborns by competitive in vitro enzyme-linked immunosorbent assay (ELISA) along with malondialdehyde (MDA) as marker of lipid peroxidation and total antioxidant status to study the oxidative stress.

RESULTS

Significant elevation in the levels of 8-OHdG along with malondialdehyde has been noted in preterm LBW newborns. Serum 8-OHdG is found to be significantly and negatively correlated with birthweight (r = -0.834, p < 0.001) and gestational age of the newborn (r = -0.626, p < 0.001).

CONCLUSION

These results provide evidence of increased oxidative stress in the form of DNA damage and lipid peroxidation in premature LBW newborns, which may be responsible for different complications associated with prematurity.

Alterations of GSH and MDA levels and their association with bee venom-induced DNA damage in human peripheral blood leukocytes

Bee venom (BV) has toxic effects in a variety of cell systems and oxidative stress has been proposed as a possible mechanism of its toxicity. This study investigated the in vitro effect of BV on glutathione (GSH) and malondialdehyde (MDA) levels, and their association with BV-induced DNA strand breaks and oxidative DNA damage in human peripheral blood leukocytes (HPBLs). Blood samples were treated with BV at concentrations ranging from 0.1 to 10 μg/ml over different lengths of time, and DNA damage in HPBLs was monitored with the alkaline and formamidopyrimidine glycoslyase (FPG)-modified comet assays, while GSH and MDA levels were determined in whole blood. Results showed a significant increase in overall DNA damage and FPG-sensitive sites in DNA of HPBLs exposed to BV compared with HPBLs from controls. An increase in DNA damage (assessed with both comet assays) was significantly associated with changes in MDA and GSH levels. When pretreated with N-acetyl-L-cysteine, a source of cysteine for the synthesis of the endogenous antioxidant GSH, a significant reduction of the DNA damaging effects of BV in HPBLs was noted. This suggests that oxidative stress is at least partly responsible for the DNA damaging effects of BV.

Polycyclic aromatic hydrocarbon (1-OHPG and 2-naphthol) and oxidative stress (malondialdehyde) biomarkers in urine among Korean adults and children

Using the urinary biomarkers 1-hydroxypyrene-glucuronide (1-OHPG), 2-naphthol, and malondialdehyde (MDA), we evaluated seasonal and regional variations in polycyclic aromatic hydrocarbon (PAH) exposure and oxidative stress among Korean adults and children. In total, 322 children (175 male and 147 female) and 332 adults (47 male and 285 female) were recruited in two regions of Korea, one representing a metropolitan area (Seoul/Incheon) and the other an industrial (Pohang) area, from winter 2002 to spring 2003. The subjects voluntarily gathered their first morning urine void, which was immediately transported to our laboratory and stored at -20 °C. Urinary 1-OHPG was measured by synchronous fluorescence spectroscopy, 2-naphthol by HPLC, and urinary MDA by HPLC with a UV detector. The median urinary 1-OHPG concentration tended to be higher in the industrial region than in the metropolitan region (0.92 vs. 0.77 ng/mL; p=0.03), and higher in winter than in spring (0.95 vs. 0.73 ng/mL; p<0.001). The median 2-naphthol concentration was also higher in the industrial region than in the metropolitan region (21.0 vs. 12.3 ng/mL; p<0.0001), but was higher in spring than in winter (19.7 vs. 10.3 ng/mL; p<0.0001). The median MDA concentration was significantly higher in winter than in spring (2.19 vs. 1.03 μmol/L; p<0.0001), whereas regional variation in MDA was observed only in female adults (p=0.02). In winter, the level of 1-OHPG was higher in children exposed to environmental tobacco smoke than in unexposed children (0.94 vs. 0.86 ng/mL; p=0.02). Our results indicate that both region and season can significantly influence the levels of PAH exposure and oxidative stress biomarkers.

Effects of vitamin E ingestion on plasma and urinary risk factors for calcium oxalate urolithiasis in two population groups having different stone-risk profiles: evidence of different physiological handling mechanisms

It has been demonstrated that vitamin E supplementation reduces calciuria and oxaluria and that it may also prevent oxalate-mediated peroxidative injury, all of which reduce the risk of calcium oxalate urolithiasis. In view of the significant difference in stone occurrence in black (B) and white (W) South Africans, we undertook to investigate the effects of vitamin E supplementation in subjects from these two groups. Five healthy males from each group ingested one capsule (400 IU) of vitamin E daily for 60 days. Blood and 24 h urine samples were collected at baseline and on day 60; 24 h dietary questionnaires were simultaneously completed. Urine composition was determined by routine analyses. Urinary and plasma TBARS were determined using a commercially available assay kit while plasma vitamin E was determined by reverse phase HPLC. Plasma vitamin E increased significantly in W but not in B. Urinary and plasma TBARS did not increase in either group. Urinary citrate increased significantly in both groups but the percentage increase in W (169%) was greater than that in B (82%). No other urinary parameter changed significantly. The increase in plasma vitamin E in W but not in B suggests either that the mechanism by which it is packaged into chylomicrons, which are secreted into the systemic circulation, is suppressed in the latter group or that it is differentially absorbed in the two groups. Similarly, to explain the greater increase in citraturia in W compared to B, we speculate that inhibition of lipogenesis of arachidonic acid by vitamin E, ultimately leading to an increase in citraturia, occurs to a lesser extent in B than in W.

Fatty liver index as an indicator of metabolic syndrome

OBJECTIVE

The aim of this study was to find an early indicator of metabolic syndrome (MetS).

DESIGN AND METHODS

We measured several anthropometric, biochemical, haematological, and oxidative damage parameters in 128 middle-aged Caucasian men divided into two groups: patients with MetS (n=69) and healthy controls (n=59), and used Weka REPTree and SimpleCART algorithms to identify the most reliable predictor of MetS.

RESULTS

Oxidative damage parameters did not differ between the groups, suggesting that oxidative damage is less prominent at the early stage of MetS. The algorithms singled out fatty liver index (FLI) as the best variable for discriminating between healthy and MetS subjects. This finding was confirmed by the receiver-operating characteristic (ROC) curve analysis, which set FLI 68.53 as the threshold value for MetS diagnosis.

CONCLUSIONS

FLI is the most reliable tool for diagnosing MetS. The absence of oxidative damage does not rule out oxidative stress but may indicate that MetS is at an early stage.

Oxidative stress and antioxidant status in primary bone and soft tissue sarcoma

BACKGROUND

Oxidative stress is characterised by an increased level of reactive oxygen species (ROS) that disrupts the intracellular reduction-oxidation (redox) balance and has been implicated in various diseases including cancer. Malignant tumors of connective tissue or sarcomas account for approximately 1% of all cancer diagnoses in adults and around 15% of paediatric malignancies per annum. There exists no information on the alterations of oxidant/antioxidant status of sarcoma patients in literature. This study was aimed to determine the levels of oxidative stress and antioxidant defence in patients with primary bone and soft tissue sarcoma and to investigate if there exists any significant differences in these levels between both the sarcomas.

METHODS

The study cohort consisted of 94 subjects; 20 soft tissue sarcoma, 27 primary bone sarcoma and 47 healthy controls. Malondialdehyde (MDA) and protein carbonyls were determined to assess their oxidative stress levels while antioxidant status was evaluated using catalase (CAT), superoxide dismutase (SOD), thiols and trolox equivalent antioxidant capacity (TEAC).

RESULTS

Sarcoma patients showed significant increase in plasma and urinary MDA and serum protein carbonyl levels (p < 0.05) while significant decreases were noted in TEAC, thiols, CAT and SOD levels (p < 0.05). No significant difference in oxidative damage was noted between both the sarcomas (p > 0.05).

CONCLUSIONS

In conclusion, an increase in oxidative stress and decrease in antioxidant status is observed in both primary bone and soft tissue sarcomas with a similar extent of damage. This study offers the basis for further work on whether the manipulation of redox balance in patients with sarcoma represents a useful approach in the design of future therapies for bone disease.

In vivo antioxidant potential of Sweet chestnut (Castanea sativa Mill.) wood extract in young growing pigs exposed to n-3 PUFA-induced oxidative stress

BACKGROUND

Farm animals in intensive farming systems are frequently exposed to oxidative stress, which demands adequate antioxidant protection. The aim of this study was to evaluate the antioxidant potential of different concentrations of Sweet chestnut wood extract (SCW; 0.75, 1.5 and 3 g kg⁻¹) in case of n-3 PUFA-induced oxidative stress in young pigs.

RESULTS

The highest concentration (3 g kg⁻¹) of SCW decreased malondialdehyde excretion in urine by 31.7%, but had no effect on plasma malondialdehyde. A linear trend towards decrease of urine isoprostanes iPF(2α)-VI was observed with the addition of SCW. All three concentrations of SCW efficiently protected blood lymphocytes from DNA damage and lowered plasma alanine aminotransferase levels. The antioxidative and antigenotoxic effect of 3 g SCW kg⁻¹ feed was comparable to the effect of 90.4 mg kg⁻¹ of added vitamin E.

CONCLUSION

The results from this study show that, besides being known as antihelmintic, antimicrobial and antiviral agent, Sweet chestnut wood extract could also be considered as a promising natural antioxidant in animal nutrition.

Evaluation of genome damage and its relation to oxidative stress induced by glyphosate in human lymphocytes in vitro

In the present study we evaluated the genotoxic and oxidative potential of glyphosate on human lymphocytes at concentrations likely to be encountered in residential and occupational exposure. Testing was done with and without metabolic activation (S9). Ferric-reducing ability of plasma (FRAP), thiobarbituric acid reactive substances (TBARS) and the hOGG1 modified comet assay were used to measure glyphosate's oxidative potential and its impact on DNA. Genotoxicity was evaluated by alkaline comet and analysis of micronuclei and other nuclear instabilities applying centromere probes. The alkaline comet assay showed significantly increased tail length (20.39 microm) and intensity (2.19%) for 580 microg/ml, and increased tail intensity (1.88%) at 92.8 microg/ml, compared to control values of 18.15 mum for tail length and 1.14% for tail intensity. With S9, tail length was significantly increased for all concentrations tested: 3.5, 92.8, and 580 microg/ml. Using the hOGG1 comet assay, a significant increase in tail intensity was observed at 2.91 microg/ml with S9 and 580 microg/ml without S9. Without S9, the frequency of micronuclei, nuclear buds and nucleoplasmic bridges slightly increased at concentrations 3.5 microg/ml and higher. The presence of S9 significantly elevated the frequency of nuclear instabilities only for 580 microg/ml. FRAP values slightly increased only at 580 microg/ml regardless of metabolic activation, while TBARS values increased significantly. Since for any of the assays applied, no clear dose-dependent effect was observed, it indicates that glyphosate in concentrations relevant to human exposure do not pose significant health risk.

Evaluation of DNA damage and lipoperoxidation of propofol in patients undergoing elective surgery

BACKGROUND AND OBJECTIVES

Inhaled anaesthetics have been studied regarding their genotoxic and mutagenic potential in vivo. Propofol differs from volatile anaesthetics because it does not show mutagenic effects and it has been reported to be an antioxidant. However, there are no studies with propofol and genotoxicity in vivo. The study aimed to evaluate the hypothesis that propofol is not genotoxic and it inhibits lipid peroxidation [malondialdehyde (MDA)] in patients undergoing propofol anaesthesia.

METHODS

ASA physical status I patients scheduled for elective surgery, lasting at least 90 min, were enrolled in this study. Initially, the estimated plasma concentration of propofol was targeted at 4 microg ml(-1) and then maintained at 2-4 microg ml(-1) until the end of surgery. Haemodynamic data were determined at baseline (before premedication) and in conjunction with target-controlled infusion of propofol: after tracheal intubation, 30, 60 and 90 min after anaesthesia induction and at the end of the surgery. Venous blood samples were collected at baseline, after tracheal intubation, at the end of the surgery and on the postoperative first day for evaluating DNA damage in white blood cells (WBCs), by comet assay, and MDA levels.

RESULTS

Haemodynamic data did not differ among times. No statistically significant differences were observed for the levels of DNA damage in WBCs, nor in plasma MDA, among the four times.

CONCLUSION

Propofol does not induce DNA damage in WBCs and does not alter MDA in plasma of patients.

Irinotecan side effects relieved by the use of HI-6 oxime: in vivo experimental approach

Some compounds, although not primarily designed as supportive drugs in chemotherapy, are promising candidates for clinical use. The ability of HI-6 oxime to relieve the side effects of irinotecan was recently determined in vitro. In this animal study, we investigated the efficacy of HI-6 in vivo, when given as a pre-treatment and concomitantly with irinotecan. We evaluated the cholinesterase (ChE)/acetylcholinesterase (AChE) activity, the levels of oxidative stress markers, DNA damage and the radical scavenging capacity of HI-6. Both HI-6 and irinotecan inhibited ChE/AChE activity but showed different levels of ChE inhibition in plasma and AChE inhibition in the liver and brain tissue. We also observed a weak antioxidant capacity of HI-6, undiscovered until now, and found an acceptable genotoxicity profile in three types of somatic cells in rats. The in vivo erythrocyte micronucleus assay showed that HI-6 did not significantly change either the frequency of micronuclei or the ratio of polychromatic and normorchromatic erythrocytes. Taken together, our results provide a good argument in favour of HI-6 as a promising molecule for further studies and eventual use in humans.

Early toxic effects of fumonisin B1 in rat liver

Mycotoxin fumonisin B1 (FB1) is hepatotoxic and carcinogenic in experimental animals. It is known that long-term exposure of experimental animals to FB1 causes apoptosis and lipid peroxidation. In this study, male adult Wistar rats were treated with single FB1 doses (5, 50, and 500 μg/kg b.w.) and sacrificed 4, 24, and 48 hours after treatment. Parameters of oxidative stress, histopathological changes, and DNA damage were monitored in the liver of treated and control animals. Parameters of oxidative stress were not affected by such treatment. A significant increase in apoptotic cells appeared in animals when 5 μg/kg b.w. dose was given and sacrificed after 24 hours with further increase at higher doses. In contrast to the number of mitotic figures and karyomegaly seen mostly at lower FB1 doses, necrosis was the prominent feature at higher doses. Significant increase in liver cells DNA mobility was observed 48 hours following treatment with 50 and 500 μg/kg b.w. as compared to control (tail length 15.2 ± 0.3, 16.4 ± 0.5, and 13.5 ± 0.1 μm, respectively). Tail intensity appeared to be more sensitive parameter for detecting DNA damage even at 5 μg/kg b.w. after 48 hours (1.69 ± 0.27% DNA; control 0.59 ± 0.11% DNA). This study proved that FB1-induced DNA damage is time- and dose-dependent, and that it could be caused in Wistar rats by a single dose.