On Oxidative Stress Research Articles

GSTM1 null‐allele polymorphism, oxidative stress and HIV disease progression in an HIV‐infected population

ObjectiveTo examine the effects GSTM1 null‐allele polymorphism on oxidative stress (OS) and disease progression in HIV+ adults.MethodsGSTM1 genotype was determined by quantitative PCR. OS (mitochondrial 8‐oxo‐2′‐deoxyguanosine, and Complex I and IV) and HIV disease (CD4 count and viral load) markers were measured in 129 HIV+ adults. Those with BMI >;28kg/m2 were excluded. Gene copies were not quantified, thus the Hardy‐Weinberg formula was not applicable.ResultsFunctional GSTM1 occurred in 66% (62/94) Blacks, and 33% (11/33) of the Caucasians. Those with functional GSTM1 had higher CD4 count (β=5.55, p=0.04), and lower viral load (β=−1.11, p=0.001), and mitochondrial 8‐oxo‐2′‐deoxyguanosine (β−0.28, p=0.03). Complex I activity (β=7.53. p=0.04) was increased over time compared to those with null‐allele GSTM1, controlling for other variables affecting OS.ConclusionThe presence of a functional GSTM1 genotype is associated with improved antioxidant activity over time. GSTM1 null‐allele polymorphism appears to have a detrimental effect on immune function and viral load control, suggesting a potential benefit from antioxidants in HIV infected patients with the defective gene.Supported by NIDA

Seasonal variability of antioxidant biomarkers in mud crabs (Scylla serrata)

Studies on oxidative stress (OS) in crustacea are widely used as ecotoxicological indices to assess the environment risk produced by the impact of several stressor and pollutants. In the present study, effects of seasonality on OS physiology markers such as antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase), small antioxidant molecules (ascorbic acid and reduced glutathione), oxidative stress indices (lipid peroxidation, protein carbonylation and hydrogen peroxide) and total antioxidant capacity in hepatopancreas, gills and abdominal muscle of adult mud crab Scylla serrata, sampled from Chilika lagoon of India, were determined in winter, summer and rainy seasons. Results indicate that variations in enzymatic and non-enzymatic antioxidants with relation to season were not only tissue specific but also were gender specific. The levels of OS parameters were higher in hepatopancreas in comparison to gills and abdominal muscle of the crabs in all seasons. OS indices in tissues of the crabs were mainly higher in summer season when temperature and salinity of the lagoon were high with low oxygen content. Although OS was lower in winter season and moderate in rainy season in tissues of male crabs, it was higher in gills and hepatopancreas of females in rainy season. Correlation analyses between hydrological parameters of the lagoon (temperature, salinity and dissolved oxygen content) and OS physiology parameters in tissues of crabs suggest that abiotic factors influence the levels of antioxidant enzymes and, thereby the OS status in a tissue and sex specific manner. Collectively, the results of the present work suggest that further investigation is warranted before using OS parameters in S. serrata as biomarkers to monitor estuarine environment as these are influenced by gender, tissue and season.

Effects of Parboiled Rice Diet on Oxidative Stress Parameters in Kidney of Rats with Streptozotocin-Induced Diabetes

The effect of parboiled rice (PR) and white rice (WR) diets on oxidative stress (OS) parameters was investigated in the kidneys of rats with streptozotocin-induced diabetes (40 mg kg(-1), iv). The experimental groups (n=8) were control fed with PR (CPR), control fed with WR, diabetic fed with PR, and diabetic fed with WR. After 30 days of treatment, all animals were anesthetized and exsanguinated before removal of kidneys, which were used to determine thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides, carbonyl protein, superoxide dismutase, catalase, glutathione peroxidase (GPx), glutathione reductase, glutathione-S-transferase activities, and levels of glutathione (GSH). Total phenolic compounds were determined in WR and PR grains. Our data indicated that diabetes induced increase in TBARS and lipid hydroperoxides levels. Although PR has not prevented the rise in the levels of these measurements, its consumption by our animals resulted in higher GPx activity and GSH content than that of the CPR. Moreover, PR also presented concentration of total phenolic compounds 127% higher than WR grains. Thus, its consumption in this diabetic condition is suggested because this seems to confer greater protection against OS in the renal tissue of diabetic animals.

Evaluation of oxidative stress after treatment with low estrogen contraceptive either alone or associated with specific antioxidant therapy

BackgroundThe aim of the study is to analyze the effect of low estrogen contraceptives (OC) on oxidative stress (OS) and concomitantly also the changes produced by different treatments using physiological modulators (PMs) with antioxidant action. Study DesignSixty-four female volunteers using a low estrogen OC regimen were analyzed for their OS status through the reactive oxygen metabolites-derived compounds (d-ROMs) test, during 5 different cycles (Cycle I to V). Three experiments were performed. ResultsIn the first experiment (Cycle I), OS showed almost a constant 50% increase in all the determinations. In the second experiment (Cycles II and III), the participants were divided into two groups and treated double-blind with a placebo or with a PM (MF Templar®) that significantly reduced OS, on average by 69%, while the placebo had no effect. In the third experiment (Cycles IV and V), the placebo group was divided into three subgroups, A, B, C and treated, respectively, with MF Templar®, green tea containing the same amount of catechins present in MF Templar® or with MF Templar® devoid of catechins. Only the complete product, MF Templar®, was able to reduce OS levels, on average by 70%. ConclusionWe conclude that to control the OS generated by OC, specific types of PMs are needed. In particular MF Templar® was able to induce a significant reduction of OS levels.

Effect of a self-care program on oxidative stress and cognitive function in an older Mexican urban-dwelling population.

To determine the effect of a self-care program on oxidative stress (OxS) and cognitive function in an older, Mexican, urban-dwelling population. A longitudinal and pre-experimental study was carried out in a sample of 79 older healthy, urban-dwelling individuals residing in Mexico City, (62 females and 17 males), of which 71 of them (59 women and 12 males) complied with the entire self-care program. We measured OxS, cognitive function, the Nagi Disability Scale of physical task functioning, and Instrumental Activities of Daily Living (IADL) prior to and after 2 years of intervention with an active aging program. All older persons adopted healthy, self-care-based lifestyles according to the active aging program to which they were trained, which was associated with a statistically significant improvement of OxS and cognitive function markers on comparing pre- and post-community intervention data. Our findings suggest that self-care-based healthy lifestyles programs can improve the oxidative stress and cognitive function in urban-dwelling elderly population.

Influence of the placebo effect on oxidative stress in healthy older adults of Mexico City

The placebo effect has been widely recognized in the randomized clinical trials; nevertheless, this effect has not been evaluated in terms of antioxidant therapy on oxidative stress (OxS). The objective of this study was to determine the influence of the placebo effect on OxS in healthy older adults of Mexico City. We carried out a double-blind controlled clinical assay with the participation of 75 healthy older adults residents for the past 10 years of Mexico City; randomly distributed into three groups of 25 subjects each after previous informed consent; control group not received any treatment, placebo group received a placebo with a pharmaceutical presentation similar to that of the treatment, whereas treatment group were administered 1000 mg of ascorbic acid and 400 IU of alpha-tocopherol. All subjects ingested the treatment daily according to study group for 12 months. We measured before and after 12 months of treatment, lipoperoxides levels (LPO), erythrocyte superoxide dismutase, glutathione peroxidase and total plasma antioxidant status with Randox Laboratories Ltd kits. The concentration of ascorbic acid and alpha-tocopherol were measured using high-performance liquid chromatography. The placebo group subjects showed a statistically significant decrease in LPO concentration, in the same way as the treatment group subjects (P < 0.01), both in comparison with a control group. Our findings suggest that the placebo has a significant effect on OxS.

Alagebrium Chloride Protects the Heart Against Oxidative Stress in Aging Rats

To investigate the possible effects of alagebrium chloride (ALT-711) on oxidative stress (OS) process in aging hearts, we examined the role of ALT-711 in cardiac function and OS in the heart of aging rats. Increased mitochondrial DNA (mtDNA) deletion as well as nearly a twofold increase in advanced glycation end products (AGEs) accumulation were observed in aging heart, whereas only about 50% of the superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities were seen. However, after treatment with ALT-711, preserved cardiac diastolic function accompanied with reduced mtDNA deletion and about 30% of AGEs decrease was observed in aging hearts. In addition, ALT-711 can increase SOD and GSH-PX activities in aging hearts as well as in cultured cardiomyocytes. In conclusion, our study suggests that AGEs accumulation and the abnormalities in the OS in aging hearts can be attenuated by ALT-711, and this might be a novel underlying mechanism for ALT-711 in the treatment of cardiovascular diseases that develop with aging.

Effects of Muscle Stress on Oxidative Stress

The purpose of this study was to examine the effect on oxidative stress (OS) of muscle stress caused by different training sets. Twenty-five healthy volunteers (22.0 ± 2.6 years old) with no past history of medication were recruited for this study. A free radical analytical system was used to measure OS (hydroperoxide consistency), and blood specimens were collected from volunteers' finger tips on three occasions: 1) at rest, 2) immediately after test completion, and 3) thirty minutes after test completion. Muscle Stress was assessed by an isokinetic testing and training system, and eccentric contraction was carried out in different training sets (10 times × 5 sets, 5R; and 10 times × 10 sets, 10R) for right knee extension. OS showed a significant increase under 10R (p<0.05), but OS values were changes within the normal range when averaged for the analysis. However, OS did not show an increase in 5R. Blood pressure (BP) and heart rate (HR) showed significant increases immediately after both 5R and 10R,compared to the rest period (p<0.001 for both). OS in muscle stress was affected by the training sets, but it was not the significantly related to BP or HR.

Free radicals in Parkinson's disease.

Although there are a number of hypotheses to explain the pathobiochemistry of Parkinson's disease (PD), the one on oxidative stress (OS) has gained major interest. The evidence for OS participation as a cause of PD can be summarized as follows: 1) OS is involved in physiological aging, 2) there is ample evidence that OS is significantly enhanced in PD compared to age-matched healthy persons, 3) OS is an early feature of PD because OS-dependent aggregation of proteins in the form of advanced glycation end products can be imaged in Lewy bodies at a time in a person's life, when no phenotype of a neurodegenerative disorder is evident, 4) Experimental models of PD show OS and degeneration of dopaminergic neurons. The toxin-induced neurodegeneration can be blocked by antioxidants, and 5) Activated microglia, known to release free radicals and inflammatory cytokines, are present in brains of Parkinsonian patients. In conclusion, a great body of evidence points to the view that OS is a major component underlying the pathobiochemistry of PD. Together a genetic disposition and endogenous/exogenous toxic events of various origins result in a synergistic cascade of toxicity which leads to dysfunction and finally to cell death of dopaminergic neurons. Again, OS plays a significant role in generating cell death signals including apoptosis.

A STUDY ON OXIDATIVE STRESS IN LEAD-EXPOSED WORKERS

To explore the possible oxidative stress induced by lead, heparinized whole blood and urine of 66 secondary smelter lead workers (46 for Comet assay) and 28 controls were collected. The concentrations of blood lead (BPb) and urinary lead (UPb) and alpha-aminolevulinic acid (-ALA), indices of lead exposure level of the body, were determined. Malondialdehyde (MDA) concentrations and superoxide dismutase (SOD) activity of plasma were also measured. Single-cell gel (SCG, Comet assay) was used to measure the DNA damage of peripheral blood cells. There was a positive correlation between the presence of Pb in blood and significant increases in MDA levels and SOD activity. Alcohol consumption and smoking with increased exposure to Pb was associated with enhanced DNA damage. A positive correlation was found between MDA and DNA damage.