Differences In Malondialdehyde Levels Research Articles

Effects of vitamin E, selenium and vitamin C on various biomarkers following oxidative stress caused by diazinon exposure in rainbow trout

Biochemical parameters are appropriate biomarkers to assess the effects of pesticides on an aquatic ecosystem. Diazinon is an organophosphate pesticide whose metabolism in fish body produces reactive oxygen species that can cause oxidative stress. In this study, Oncorhynchus mykiss were allocated into four treatment groups (with three replicates): control; Diazinon; vitamin C + diazinon, and vitamin E,selenium + diazinon. Blood samples were obtained after two and four weeks and superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC), and malondialdehyde (MDA) were measured. SOD activity was significantly lower in diazinon-exposed fish than in the control group. However, there were no differences between the two supplemented groups and the control group in this regard. CAT activity was significantly higher in all three diazinon-exposed groups compared to the control group. However vitamin E, selenium had the least difference with the control group. Maximum and minimum TAC were observed respectively in fish supplemented with vitamin E, selenium and those only exposed to diazinon. The diazinon group also had the highest MDA levels. The two supplemented groups and the control group had no significant differences in MDA levels. These findings highlighted the antioxidant effects of supplementation with vitamin E, selenium or vitamin C against free radical produced during the metabolism of diazinon. Meanwhile, the combination of vitamin E, selenium had higher antioxidant effects than vitamin C. Moreover, SOD, the first defensive barrier against superoxide radicals, and MDA, an index of cellular damage induced by hydroxyl radicals, are the most suitable indicators to assess the effects of diazinon.

Effects of Vitamin E, Selenium and Vitamin C on Various Biomarkers Following Oxidative Stress Caused by Diazinon Exposure in Rainbow Trout

Biochemical parameters are appropriate biomarkers to assess the effects of pesticides on an aquatic ecosystem. Diazinon is an organophosphate pesticide whose metabolism in fish body produces reactive oxygen species that can cause oxidative stress. In this study, Oncorhynchus mykiss fish were allocated into four treatment groups (with three replicates): control; Diazinon (0.1 mg L 1); vitamin C (300 mg kg 1 in diet) plus diazinon (0.1 mg L 1) and vitamin E, selenium (selenium 0.5 & vitamin E 100 mg kg-1 in the diet) plus diazinon (0.1 mg L 1). Blood samples were obtained after two and four weeks and superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC) and malondialdehyde (MDA) were measured. SOD activity was significantly lower in diazinon-exposed fish than in the control group. However, there were no differences between the two supplemented groups and the control group in this regard. CAT activity was significantly higher in all three diazinon-exposed groups compared to the control group. However vitamin E, selenium had the least difference with the control group. Maximum and minimum TAC were observed respectively in fish supplemented with vitamin E, selenium and those only exposed to diazinon. The diazinon group also had the highest MDA levels. The two supplemented groups and the control group had no significant differences in MDA levels. These findings highlighted the antioxidant effects of supplementation with vitamin E, selenium or vitamin C against free radical produced during the metabolism of diazinon. Meanwhile, the combination of vitamin E, selenium had higher antioxidant effects than vitamin C. Moreover, SOD, the first defensive barrier against superoxide radicals and MDA, an index of cellular damage induced by hydroxyl radicals, are the most suitable indicators to assess the effects of diazinon.

Effect of Yeast Probiotic on Growth, Antioxidant Enzyme Activities and Malondialdehyde Concentration of Broiler Chickens.

The aim of the study was to determine the effect of yeast probiotic on body weight, and the activities of anti-oxidant enzymes: superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), and malondialdehyde (MDA) concentration of broiler chickens. The experiment was carried out on hybrid Hubbard broiler chickens (n = 200). Two-hundred day-old chicks were randomly selected and distributed into four groups of 50 day-old chicks each: Control, C, and treatment groups comprising T1, T2 and T3 administered with 0.25 mL, 0.5 mL and 1.0 mL yeast probiotic, respectively. Chicks were fed a commercial starter diet for the first 28 days of age, followed by pelleted finisher diet from 29 to 42 days. Chickens in T1 had a significantly (p < 0.01) higher body weight at 4th week of age when compared with the control. SOD activity in all treatment groups was not significantly (p > 0.05) different when compared with the control. GPx activity was significantly (p < 0.01) higher in T1, when compared with the control. GPx activity in T2 was higher (p < 0.01) when compared with the control. There was no significant (p > 0.05) difference in MDA level in all the treatment groups. In conclusion, administering yeast probiotic supplement increased body weight and enhanced serum anti-oxidant enzyme activities of broiler chickens.

EFEK KEFIR TERHADAP GAMBARAN HISTOLOGIS DAN KADAR MALONDIALDEHIDE HEPAR MENCIT PUTIH (MUS MUSCULUS) JANTAN GALUR BALB C DENGAN PAPARAN FORMALIN

Kefir is a probiotic drink act as therapeutic agents in liver damage caused by exposure of formaldehyde. Therapeutic activities were estimate based on the content of kefir like antioxidants, lactic acid bacteria with yeasts, and essential amino acids. The purpose of this study was to prove the influence of kefir on the histological and levels of malondialdehyde (MDA) in liver of white mice (Mus musculus) male Balb C strain that exposure by formalin. The method used is experimental method, with three treatment groups, namely: (1) normal group, (2) the induction of formaline without kefir therapy group, (3) the induction of formaline with kefir therapy group. Histological of liver viewed by HE staining and MDA levels were measured by TBARS method. There are differences in the average number of significant cell damage induced by formalin group (p = 0030, p &lt; 0.05). There are significant differences in MDA levels induced by formalin group (p = 0023, p &lt; 0.05). These results are based on the ability of vitamin C, E and carotene (antioxidant) against Reactive Oxygen Species (ROS) due to exposure of formaldehyde, thus preventing the MDA levels increasing. Lactic acid bacteria and yeasts can preclude the possibility of healthy cells to be attacked by ROS with increasing the body’s immunity. Essential amino acids can repairing damaged cells by stimulating cell regeneration. It can be concluded that kefir with a dose of 107 CFU / ml act as therapeutic agents in liver damage due to exposure to formaldehyde.

Oxidative stress is closely associated with insulin resistance in genotypes 1 and 3 chronic hepatitis C.

Chronic hepatitis C (CHC) infection is associated with insulin resistance and with oxidative stress, but the relationship between the two has not been thoroughly examined. To evaluate the association between insulin resistance and oxidative stress in CHC patients. In 115 CHC patients (68 with genotype 1 and 47 with genotype 3), the relationship between the serum concentration of malondialdehyde (MDA), a marker of oxidative stress and insulin resistance as defined by the homeostasis model (HOMA-IR) was examined. There was no significant difference in MDA levels between genotype 1- and genotype 3-infected subjects (12.882 vs. 12.426ng/mL, p=0.2). By univariate analysis, factors associated with HOMA-IR in both genotypes were oxidative stress as measured by MDA (p=0.002), body mass index (BMI), portal activity, and fibrosis. Genotype-specific differences in HOMA-IR association were steatosis and triglycerides (TG) for genotype 1, and age and glutathione (GSH) for genotype 3. In a stepwise multiple linear regression analysis in both genotypes, MDA was a significant and independent predictor of HOMA-IR (p=0.04). As expected, BMI and fibrosis were likewise independently correlated to HOMA-IR. In addition, MDA levels were higher (p<0.001) and GSH levels were lower (p=0.023) in insulin-resistant subjects compared to their insulin-sensitive counterparts. It is concluded that in CHC, oxidative stress is an independent predictor of HOMA-IR, irrespective of virus genotype. Further studies on the role of oxidative stress in the development of insulin resistance in CHC are warranted.

Nutritional and Hormonal Induction of Fatty Liver Syndrome and Effects of Dietary Lipotropic Factors in Egg-type Male Chicks.

This experiment was conducted with male chicks to investigate the influence of hormones and nutrients on the development of fatty liver syndrome (FLS) as well as the effects of dietary lipotropic factors on hepatic fat accumulation and lipogenic enzyme gene expression. A total of two-hundred sixteen 4-wk-old Hy-Line male chicks were divided into six groups and fed an experimental diet (T1, low-energy diet with low levels of lipotropic factors; T2, high-energy diet with low levels of lipotropic factors; T3 and T5, low-energy diet with high levels of lipotropic factors; T4 and T6, high-energy diet with high levels of lipotropic factors) for six weeks. The chicks in T5 and T6 groups were treated with intramuscular injections of estradiol benzoate for three days prior to biopsy and clinical analysis of FLS. Chicks treated with estrogen had significantly greater liver weights than untreated chicks. The abdominal fat contents were increased in chicks consuming high-energy diets as compared to those consuming low-energy diets. Treatment with estrogen significantly increased the concentrations of serum cholesterol, triacylglycerol and phospholipid (p<0.05). The hepatic triacylglycerol levels were tenfold higher in the estrogen treated chicks than in the untreated chicks. There were no significant differences in malondialdehyde levels between the treatment groups. Estrogen treatment dramatically increased the levels of fatty acid synthetase, acetyl-CoA carboxylase and ApoB mRNA. The results indicated that treatment with exogenous estrogen in growing male chicks induced hepatic fat accumulation, which might be partially due to increased lipogenic enzyme gene expression.

Lipid peroxidation/antioxidant activity in patients with alopecia areata

Aetiopathogenesis of alopecia areata (AA) is not fully understood and many factors have been assumed. Oxidant/antioxidant disequilibrium has been proposed with controversies between results. The aim of this study was to determine lipid peroxidation/antioxidant activity in patients with AA and to determine its clinical significance. Fifty non-obese patients with AA and 50 age-, gender- and body mass index-matched controls (25 patients with severe grade acne vulgaris representative of an oxidative stress condition and 25 healthy volunteers), were included. Levels of malondialdehyde (MDA), indicator of lipid peroxidation and antioxidant activity of superoxide dismutase (SOD), were spectrophotometrically measured in blood from all subjects and in scalp tissues from 10 patients with AA. No significant differences in MDA levels and SOD activity existed between patients with AA and those with acne. However, significantly higher MDA levels and lower SOD activity were found in patients with AA compared with healthy controls. Within patients with AA, lipid peroxidation/antioxidant parameters showed significant differences with disease duration, pattern and extent of lesions. Significant positive correlations also existed between tissue and blood SOD activity and between tissue and blood MDA levels of the 10 studied patients with AA. Increased lipid peroxidation and defective SOD activity exist in patients with AA. Addition of drugs with antioxidative effects seems to be valuable in treatment.

Serum Paraoxonase Activity and Oxidative DNA Damage in Patients With Laryngeal Squamous Cell Carcinoma

To determine the possible role of oxidants and antioxidants in the pathogenesis of in laryngeal squamous cell carcinoma. Our study involved patients with newly diagnosed laryngeal cancer (n = 29) and same age- and sex-matched healthy individuals (n = 21). Serum malondialdehyde (MDA) and paraoxonase (PON1) levels were measured by colorimetric methods and 8-hydroxy-2'-deoxyguanosine (8-OH-dG) was measured using enzyme-linked immunosorbent assay in fasting blood samples of participants. The levels of 8-OH-dG (control, 4.61 ± 1.27 ng/mL; patient, 11.70 ± 2.44 ng/mL; P < 0.001) and MDA (control, 4.16 ± 1.02 nmol/mL; patient, 8.74 ± 1.65 nmol/mL; P < 0.001) were significantly higher, and those of PON1 (control, 170.86 ± 72.46 U/mL; patient, 80.44 ± 29.81 U/mL; P < 0.001) were significantly lower in patients. There were no statistically significant differences in the 8-OH-dG, MDA levels, and PON1 activity in relation to T (tumor) staging of differentiation and different smoking/drinking status. There was a statistically significant difference in MDA levels (10.24 ± 0.64 nmol/mL) only in stage II laryngeal cancer. There were a statistically significant positive correlation between serum MDA and 8-OH-dG (r = 0.887, P < 0.001), a statistically significant negative correlation between serum MDA and serum PON1 (r = -0.477, P < 0.01), and a statistically significant negative correlation between serum 8-OH-dG and serum PON1 in patients (r = -0.420, P < 0.05). We conclude that, in patients with laryngeal squamous cell carcinoma, the oxidant/antioxidant balance was impaired in favor of lipid peroxidation and DNA damage.

The protection of the myocardium by amifostine against mitoxantrone-induced acute cardiotoxicity in rats.

Amifostine (AMI) has been used for the prevention of doxorubicin-induced cardiotoxicity in several experimental and a few clinical studies. The aim of this study was to investigate the effects of AMI on lipid peroxidation, protective enzymes, and mitoxantrone (MITO)-induced acute cardiotoxicity in the rat heart using biochemical tests and histopathological examinations. Thirty-six rats were divided into six groups (n=6 in each). Control rats were given intraperitoneal (i.p.) serum saline and AMI group rats were given 200 mg/kg AMI i.p. Rats received MITO-2.5 and 5 mg/kg i.p. in the MITO-2.5 and MITO-5 groups. AMI 200 mg/kg i.p. was administered 30 min. before the same doses of MITO in the MITO-2.5+AMI and MITO-5+AMI groups. The levels of cardiac enzymes such as creatinine phosphokinase-myocardial band and cardiac troponin T did not change. Malondialdehyde (MDA) levels increased in MITO groups compared to controls. Catalase and glutathione (GSH) levels in the MITO and MITO+AMI groups were higher than in controls. Superoxide dismutase and glutathione peroxidase levels were not different between MITO groups and controls. There was no difference in MDA levels between MITO+AMI groups and controls. Calcium deposition was not detected. The scores of fibrosis, apoptosis, inflammation, and degeneration in MITO groups were higher than in controls. The scores of fibrosis, degeneration and inflammation in MITO+AMI groups were lower. MITO caused lipid peroxidation and myocardial damage, and the myocardium increased catalase and GSH levels to prevent this damage. AMI can protect against MITO-induced acute cardiotoxicity, decreasing myocardial damage and lipid peroxidation.

Serum neuron specific enolase and malondialdehyde in patients after out-of-hospital cardiac arrest.

Sudden cardiac arrest (CA) is a leading cause of death in Europe. The victims of CA need immediate cardiopulmonary resuscitation (CPR). Patients resuscitated due to CA have high mortality rate. Prognostic evaluation based on clinical observation is uncertain and would benefit from the use of biochemical markers of hypoxic brain damage. Multiple factors of brain origin can be measured in blood. The purpose of this study was to validate the use of the serum neuron-specific enolase (NSE) and malondialdehyde (MDA) concentrations for predicting in-hospital death, after resuscitation from out-of-hospital CA. Neuronal damage and impairment of the blood-brain-barrier integrity can be detected by the release of NSE into cerebrospinal fluid and eventually into the blood. MDA represents a product of lipid peroxide decomposition reactions. In a prospective study of 35 consecutive survivors of out-of-hospital CA, serum samples were obtained within 24, 72 and 168 h after the CA. NSE and MDA concentrations were measured, relationship between concentration in group of in-hospital death and survived patients were examined. Results There was a significant difference in NSE concentration between survivors and dead group on 1st day of measurement, marginally significant difference on 3rd day and no statistically significant difference in NSE on 7th day of measurement. There was marginally significant difference in MDA levels in both groups in all days of measurements. Estimation serum concentrations of NSE but not MDA seems to be a predictor of fate of patients after CA. The exact nature of oxidative stress can only be resolved by further studies.

The changes of cerebrospinal fluid non-protein-bound iron and malondialdehyde(MDA) in preterm infants with severe intraventricular hemorrhage (IVH) after serial lumbar punctures

Objective To investigate the changes and clinical significance of cerebrospinal fluid (CSF) non-protein-bound iron and malondialdehyde(MDA) in preterm infants with severe intraventricular hemorrhage (IVH) after serial lumbar punctures.Methods Non-protein-bound iron and MDA of CSF in twenty severe IVH preterm infants with first and end lumbar puncture were examined respectively.The control samples were determined for once from first to second week after birth.Results Both Non-protein-bound iron and MDA levels of the first CSF sample in twenty severe IVH preterm infants were higher than that in control[(0.66±0.38)μmol/L vs (0.24±0.12)μmol/L(P<0.01);(1.21±0.41)μmol/L vs (0.89±0.35)μmol/L(P<0.05)].Non-protein-bound iron levels of first and end CSF sample in severe IVH with posthemorrhagic ventricular dilatation (PHVD) were both higher than those without PHVD [(0.75±0.34)μmol/L vs (0.54±0.31)μmol/L;(0.57±0.21)μmol/L vs (0.35±0.18)μmol/L](P<0.05).However,there was no significant difference in MDA levels between both groups.The levels of non-protein-bound iron of end CSF in severe IVH with and without PHVD were significantly lower than those of the first CSF samples (P<0.05),while,there was no significant difference in MDA levels between the end and first CSF samples.Conclusion The non-protein-bound iron and MDA of CSF in severe IVH preterm infants were both significantly increased,non-protein-bound iron and oxygen free radicals may be involved in the preterm brain injury.Serial lumbar punctures can lower the levels of non-protein-bound iron in CSF. Key words: Intraventricular hemorrhage; Posthemorrhagic ventricular dilatation; Non-protein-bound iron; Malondialdehyde; Serial lumbar punctures; Preterm infant

Relationship between oxidative and occupational stress and aging in nurses of an intensive care unit.

Stressful conditions lead to formation of excessive reactive oxygen species (ROS) and cause oxidative stress and aging. The aim of this study was to determine superoxide dismutase (SOD) and catalase (CAT) activity, and malondialdehyde (MDA) levels in nurses of a hospital intensive care unit according to demographic and occupational parameters, and to analyse the relationship with aging. Thirty-two nurses working in an intensive care unit and 35 aged-matched healthy individuals of both sexes as a control group were surveyed. No significant variations with respect to sex were detected in SOD, CAT, MDA and burnout levels. MDA levels increased with age in both the control group and the nurses, and we observed significant differences in MDA levels between the control group and nurses for all age groups. Significant variations in MDA levels were detected between single (286.12 +/- 8.41) and married (318.82 +/- 6.02), people, between those who frequently practice some kind of sport (281.41 +/- 7.32) and those who never participate in sport (298.24 +/- 8.11) ,and between those who frequently eat fruit and greens (289.75 +/- 8.41) and those who never eat them (315.12 +/- 7.21). Significant differences were detected between smokers and nonsmokers in SOD, CAT and MDA, but not for alcohol, coffee, tea or cola consumption. Higher SOD activity and MDA levels were detected in nurses on evening and night shifts (P < 0.01); these nurses also scored significantly higher on burnout subscales. These results suggest that: (1) occupational stress increases oxidative stress levels as a response to elevated ROS generation; (2) occupational stress increases MDA levels as a response to an elevation in free radical generation and can lead to aging; (3) working evening and night shifts increases oxidative and burnout levels. It is evident that preventive changes in job conditions and lifestyle are necessary to improve the quality of life of nurses who work in intensive care units.

Efficacy of MCI-186, a free-radical scavenger and antioxidant, for resuscitation of nonbeating donor hearts

Oxygen-derived free radicals are responsible in part for reperfusion injury in globally ischemic myocardium. In this study, the efficacy for resuscitation of nonbeating donor hearts of MCI-186, a free-radical scavenger and antioxidant, was investigated in a pig transplantation model. Cardiac arrest was induced by asphyxiation. After 30 minutes of global ischemia, the hearts were excised and immediately reperfused from the aortic root with normoxemic blood cardioplegia (PO2 100 mm Hg) for 20 minutes, followed by perfusion with hyperoxemic blood (PO2 300 mm Hg). MCI-186 (3 mg/kg) was administered into the aortic root for the first 30 minutes of reperfusion in the treated group (n = 6), and untreated hearts were used as a control group (n = 6). Transplantation was performed with the heart beating. Posttransplantation recovery of cardiac output, end-systolic pressure-volume ratio, and first derivative of pressure of the left ventricle in the treated group were significantly better than those in the control group. The coronary sinus-aortic root difference in malondialdehyde levels remained low throughout reperfusion in the treated group but abruptly increased after initiation of oxygenated blood perfusion in the control group. The MCI-186-treated hearts showed low degree of edema and well-preserved ultrastructure with normal-appearing organelles, whereas the untreated hearts had marked swelling of mitochondria and scant glycogen granules. MCI-186 exerts a cardioprotective action at least partly by inhibition of lipid peroxidation. Antioxidant therapy at the initial reperfusion is essential to successful resuscitation of nonbeating hearts by continuous myocardial perfusion.

Circadian rhythm of malondialdehyde formation in healthy subjects

Objective:Malondialdehyde (MDA) is a common biologic marker of oxidative stress used in psychiatric research. Data regarding MDA levels in healthy subjects are controversial. One factor affecting MDA levels may stem from the existence of a circadian rhythm of MDA formation. The objective of this study consists of investigating whether MDA formation has a circadian rhythm of formation in healthy human subjects.Methods:The sample was comprised by 9 healthy male subjects. None of them had a history of medical or neurological disease and routine laboratory parameters were normal. The study was carried out in accordance with the Helsinki Declaration and all subjects gave written informed consent before their inclusion. Blood samples were extracted at 12:00 and 2:00 in December 2004. The same routine was followed during the two experimental sessions. Serum MDA was determined by the thiobarbituric acid reactive substance (TBARS) according to the method of Ohkaba et al (1979).Results:The sample was comprised by 9 male healthy subjects (age 33.0±11.7). There were significant differences in MDA levels between 12:00 and 2:00 (2.33±1.01 vs. 1.58±0.48, p<0.015).Conclusions:MDA has a circadian rhythm of formation with higher levels at 12:00 than 2:00. This variation in circadian MDA levels of formation should be accounted when researching in this field.

The influence of trehalose, taurine, cysteamine and hyaluronan on ram semen: Microscopic and oxidative stress parameters after freeze–thawing process

There is a lack of information regarding lipid peroxidation and antioxidant capacity in cryopreserved ram semen, and cryopreservation is associated with the production of reactive oxygen species (ROS) which lead to lipid peroxidation (LPO) of sperm membranes, resulting in a loss of motility, viability and fertility of sperm. The aim of this study was to determine the influence of certain additives and their different doses on standard semen parameters, lipid peroxidation and antioxidant activities after the cryopreservation/thawing of ram semen. Ejaculates collected from four Akkaraman rams, a native breed of sheep, were evaluated and pooled at 33 °C. Semen samples which were diluted with a Tris-based extender containing additives including trehalose (50, 100 mM), taurine (25, 50 mM), cysteamine (5, 10 mM), and hyaluronan (0.5, 1 mg/ml), and an extender containing no additives (control) were cooled to 5 °C and frozen in 0.25 ml French straws, being stored in liquid nitrogen. Frozen straws were thawed individually at 37 °C for 20 s in a water bath for evaluation. The use of a Tris-based extender supplemented with 50 mM trehalose, 25 mM taurine, and 5 and 10 mM cysteamine led to higher percentages of post-thaw motility, in comparison to the control group ( P < 0.01). No significant differences were observed in the percentages of acrosome and total abnormalities, and the hypoosmotic swelling test upon the supplementation of the freezing extender with antioxidants after the thawing of semen. In biochemical assays, the addition of antioxidants did not cause significant differences in levels of malondialdehyde (MDA), glutathione (GSH), and glutathione peroxidase (GSH-Px), after thawing, when compared to groups with no additives. In this study, catalase (CAT) activities were higher in the group that was applied 25 mM taurine as an antioxidant, than in all of the other groups ( P < 0.001). Compared to the controls, antioxidant treatment with 100 mM trehalose, 50 mM taurine, 5 mM cysteamine and 0.5 mg/ml hyaluronan, significantly elevated vitamin E (vit E) levels in samples ( P < 0.001).

Lipid peroxidation level and antioxidant enzyme activities in the blood of patients with acute and chronic fascioliasis

In this study, we investigated the relationship between fascioliasis and serum malondialdehyde (MDA) levels, superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) activities. We also investigated whether there are significant differences in MDA levels and antioxidant enzymatic activities between acute and chronic fascioliasis. Forty fascioliasis patients who were diagnosed by ES-ELISA positivity were included in this study. The patients were classified as 18 with acute and 22 with chronic fascioliasis. In patients with fascioliasis, levels of MDA were statistically higher and erythrocyte SOD and GPx activities were statistically lower than in healthy controls. MDA levels were found to be higher in patients with acute fascioliasis than in patients with chronic fascioliasis although MDA levels were significantly higher in patients with chronic fascioliasis than in controls. There was no statistically significant difference between the two groups for the antioxidant enzyme activities. The results of this study may indicate that fascioliasis produces specific effects on the antioxidant defense mechanisms due to its inflammatory character. Our results also allow us to suggest that oxidative stress has an important role in the pathogenesis of fascioliasis and the persistence of this oxidative stress can be one of the underlying factors in the pathogenesis of the chronic disease.

The protective effect of selenium on ipsilateral and contralateral testes in testicular reperfusion injury

This study was designed to investigate the effect of selenium on ipsilateral and contralateral testicular damage after unilateral testicular torsion/detorsion (T/D). Thirty-two male rats were divided into four groups, each containing eight rats. Torsion was created by rotating the right testis 720 degrees in a clockwise direction. Group 1 underwent sham operation to determine basal values for biochemical and histopathological evaluation. Sham operation was performed in group 2, and sodium selenate (0.2 mg/kg) was given intraperitoneally. Group 3 served as a T/D group, receiving 4-h torsion and 4-h detorsion. Similarly, in group 4 sodium selenate (0.2 mg/kg) was injected intraperitoneally 20 min before detorsion. Bilateral orchiectomies were performed for measurement of tissue malondialdehyde (MDA) levels and superoxide dismutase (SOD) activities and histopathologic examination. The results were compared statistically. The highest MDA and the lowest SOD values were determined in both testes in group 3. There were statistically significant differences in MDA levels and SOD activities in group 3 compared with group 4. Specimens from group 3 had a significantly greater histologic injury than other groups. These results suggest that ischemia-reperfusion injury occurred in both testes after unilateral testicular T/D and that selenium administration before detorsion prevents reperfusion injury in testicular torsion.

Tissue levels of malondialdehyde after passive smoke exposure of rats for a 24‐week period

The present study was to evaluate the effects of chronic cigarette smoke exposure on lipid peroxidation in various organ tissues. Sprague-Dawley rats were exposed to passive smoking 2 hr per day, 6 days per week (Monday-Saturday), for 24 weeks. Malondialdehyde levels, as an index of lipid peroxidation, were measured by the thiobarbituric acid assay. Levels were significantly higher in tissues of passive-smoke-exposed groups (n=10) compared with normal-bred control groups (n=6), for red blood cells (2.17+/-0.22 vs. 1.80+/-0.39 nmol/mg), lung (1.39+/-0.32 vs. 1.03+/-0.35 nmol/mg), and spleen (1.75+/-0.33 vs. 1.42+/-0.15 nmol/mg); p<.05. No differences in malondialdehyde levels were found in plasma, heart, liver, stomach, and renal tissues. The results suggest that chronic environmental tobacco smoke exposure can increase lipid peroxidation in red blood cells and in lung and spleen tissue. This finding brings further investigative attention to the public health issue of the injurious effects of chronic passive smoke exposure.

Antioxidant Enzyme Activities and Malondialdehyde Levels in Patients with Obsessive-Compulsive Disorder

To examine the importance of free radicals in the pathogenesis of obsessive-compulsive disorder (OCD), we aimed to evaluate whether malondialdehyde (MDA), a product of lipid peroxidation, and antioxidant enzyme [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)] activity levels were associated with OCD. The patients were divided into two subgroups according to whether DSM-IV major depressive disorder (MDD) was accompanied (OCD + MDD) or not (OCD – MDD). The MDA and antioxidant enzyme levels both in patients and controls were determined. SOD activity levels were significantly higher in the OCD + MDD group compared with the control and the OCD – MDD group. Although the OCD – MDD group had slightly higher SOD activity levels as compared with the controls, the difference was not statistically significant. GSH-Px activity levels were statistically significantly higher in both groups compared with controls. Likewise, there was a significant difference in GSH-Px activity levels between the OCD + MDD and OCD – MDD group. CAT activity levels were slightly higher in the OCD + MDD group compared with the OCD – MDD and control group. MDA levels in both groups were significantly higher than in controls. In addition, the difference in MDA levels between both groups was statistically significant. In conclusion, our results suggest that OCD is associated with free radicals and that it may be a heterogeneous subtype including some biological indications of anxiety and affective disorders. More comprehensive and detailed studies are needed to decipher the exact role of free radicals in OCD.

Malondialdehyde: A Possible Marker of Ageing

Background: Numerous recent studies have suggested that oxidative damage may be important in the ageing process, and lipid peroxidation is an important biological consequence of oxidative cellular damage. Objective: The aim of this work was to analyze the activities of the two protective enzymes, superoxide dismutase (SOD) and catalase (CAT), and the levels of malondialdehyde (MDA) to examine the relationship between the ageing process and defence antioxidant and lipid peroxidation. Method: SOD activity was measured in red blood cells using the Minami and Yoshikawa method; CAT activity was measured in hemolysates by the Aebi method, and MDA levels were measured in erythrocytes by high-performance liquid chromatography. Results: SOD activity shows statistically significant differences between newborns and the rest of the sample (ANOVA p < 0.001; Student-Newman-Keuls test p < 0.001). CAT activity did not show significant differences between the age groups. We observed statistically significant differences in MDA levels between the different groups (ANOVA p < 0.001; Student-Newman-Keuls test p < 0.05). In the regression analysis and rectilinear/curvilinear adjustment compared to age, SOD and CAT showed coefficients close to zero (SOD linear = 0.16; SOD exponential = 0.15; CAT linear = 0.056; CAT exponential = 0.068), indicating in that way their independence from age. Only MDA obtained a regression coefficient superior to 0.75 (p < 0.05). The best adjustment was reached through an exponential expression, giving the following parametric relation: MDA = 103.117e^0.0021.AGE. No statistically significant variation in SOD and CAT activity and MDA levels, related to sex could be demonstrated. Conclusions: Our data show that old age is associated with an increase in systemic oxidative stress.