Plasma Thiobarbituric Acid Reactive Substances Research Articles

P35. Novel interaction of placental caveolin-1 expression with markers of oxidative stress and the renin-angiotensin system (RAS) in pre-eclampsia

Introduction Caveolin-1 (cav-1) is one of the major protein components of caveolae required for the coordination of some signalling pathways, including that of angiotensin II (AngII) with its Type 1 receptor (AT1R). We have previously reported decreased cav-1 and increased AT1R protein expression in placentae from women with pre-eclampsia (PE). Within the PE placenta, an increase in AngII acting via AT1R may lead to increased vasoconstriction, but possible functional effects of altered cav-1, and interactions with components of RAS and markers of oxidative stress have not been investigated. Objective To establish mechanistic interactions of placental cav-1 with RAS components and surrogate markers of oxidative stress and antioxidant concentrations. Methods Immunohistochemistry was performed on paraffin-embedded serial placental sections from 24 normotensive (NC) and 19 women with PE, using antibodies to cav-1, prorenin receptor (PRR), angiotensinogen (AGT), AT1R, AngII type 2 receptor (AT2R) and eNOS. Protein expression was semi-quantitatively assessed and also analysed with respect to previously measured maternal plasma TBARS (Thiobarbituric acid-reactive substances) concentration and placental glutathione peroxidase (GPx) activity. Results Positive correlations were observed between placental expression of cav-1 and the AT2R ( P = 0.003) and PRR ( P P > 0.7, P > 0.5). However, cav-1 was inversely correlated with eNOS expression in both NC and PE placentae ( P P = 0.003). No significant correlations were observed with AGT or AT1R. A negative correlation was observed between maternal TBARS and cav-1 protein ( P = 0.003), and between placental GPx activity and cav-1 protein ( P = 0.027) only in the PE placentae. Conclusions A complex cascade links activation of the AT1R with NADPH oxidase activation, generation of reactive oxygen species (ROS), the uncoupling of eNOS and subsequent modification of redox-sensitive caveolar proteins in vascular smooth muscle outside pregnancy. Our findings suggest that this cascade is altered in hypertensive pregnancy, in a direction which would lead to enhanced local vasoconstriction.

Nitric oxide and oxidative stress is associated with severity of diabetic retinopathy and retinal structural alterations.

The aim of the study was to determine plasma nitric oxide (NO) and lipid peroxide (LPO) levels in diabetic retinopathy and its association with severity of disease. Prospective observational study. A total of 60 consecutive cases and 20 healthy controls were included. Severity of retinopathy was graded according to early treatment diabetic retinopathy study (ETDRS) classification. Photoreceptor inner segment ellipsoid band (ISel) disruption and retinal pigment epithelium (RPE) alteration were graded using spectral domain optical coherence tomography. Data were statistically analyzed. Plasma thiobarbituric acid reactive substances, NO assay and reduced glutathione (GSH) were measured using standard protocol. Increased severity of diabetic retinopathy was significantly associated with increase in plasma levels of LPO (P < 0.05), NO (P < 0.001) and decrease in plasma levels of GSH (P < 0.0001), ISel disruption (P < 0.001) and RPE topographic alteration (P < 0.01). Increased plasma NO levels are associated with increased severity of diabetic retinopathy. For the first time, it has been demonstrated that increased plasma LPO, NO and decreased GSH levels are associated with in vivo structural changes in inner segment ellipsoid and RPE.

Effect of resistance training during the month of Ramadan on antioxidants and oxidative stress biomarkers in recreational bodybuilders

The aim of this study was to investigate the effect of a hypertrophic training program during Ramadan on levels of circulating antioxidants and oxidative stress biomarkers in trained bodybuilders. Eight male bodybuilders visited the laboratory two days before the start of Ramadan and on the 29th day of Ramadan (end-Ramadan), to undergo anthropometric measurement, to complete a dietary questionnaire, and to provide fasting blood and urine samples. Plasma thiobarbituric acid reactive substance and protein-bound carbonyl concentrations were measured in the plasma to indicate lipid and protein oxidation, respectively. These did not change significantly during Ramadan. Superoxide dismutase and glutathione peroxidase activities, indices of erythrocytes antioxidant status, increased by 24% (p = 0.011) and 12% (p = 0.01), respectively, from before to the end of Ramadan. However, erythrocyte catalase activity did not change significantly. Uric acid values increased by 17% (p < 0.001) from before to the end of Ramadan, but ferric-reducing ability and Vitamin E levels of the plasma remained unchanged. A significant correlation was found between uric acid values and urine specific gravity (r = 0.70; p < 0.05) only at the end of Ramadan. We conclude that continuing a hypertrophic training program during Ramadan fasting does not increase oxidative stress but does increase antioxidant status in bodybuilders.

Therapeutic potential of ixmyelocel-T, an expanded autologous multicellular therapy for treatment of ischemic cardiovascular diseases.

IntroductionBone marrow derived cellular therapies are an emerging approach to promoting therapeutic angiogenesis in ischemic cardiovascular disease. However, the percentage of regenerative cells in bone marrow mononuclear cells (BMMNCs) is small, and large amounts of BMMNCs are required. Ixmyelocel-T, an expanded autologous multicellular therapy, is manufactured from a small sample of bone marrow aspirate. Ixmyelocel-T contains expanded populations of mesenchymal stromal cells (MSCs) and M2-like macrophages, as well as many of the CD45+ cells found in the bone marrow. It is hypothesized that this expanded multi-cellular therapy would induce angiogenesis and endothelial repair.MethodsA rat model of hind limb ischemia was used to determine the effects of ixmyelocel-T on blood flow recovery. To further determine the effects on endothelial cells, ixmyelocel-T was co-cultured with human umbilical vein endothelial cells (HUVEC) in non-contacting Transwell® inserts.ResultsCo-culture of HUVECs with ixmyelocel-T resulted secretion of a variety of pro-angiogenic factors. HUVECs stimulated by ixmyelocel-T exhibited enhanced migration, proliferation, and branch formation. Ixmyelocel-T co-culture also resulted in increased endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) production. In tumor necrosis factor alpha (TNFα)-stimulated HUVECs, ixmyelocel-T co-culture decreased apoptosis and reactive oxygen species generation, increased super oxide dismutase activity, and decreased nuclear factor kappa B (NFκB) activation. Treatment with ixmyelocel-T in a rat model of hind limb ischemia resulted in significantly increased blood flow perfusion and capillary density, gene expression and plasma levels of the anti-inflammatory cytokine interleukin (IL)-10, plasma nitrates, plasma platelet-derived growth factor (PDGF)-BB, vascular endothelial growth factor (VEGF) expression, and significantly decreased plasma thiobarbituric acid reactive substances (TBARS).ConclusionsThis work demonstrates that ixmyelocel-T interacts with endothelial cells in a paracrine manner, resulting in angiogenesis and endothelial protection. This data suggests that ixmyelocel-T could be useful for promoting of angiogenesis and tissue repair in ischemic cardiovascular diseases. In conclusion, ixmyelocel-T therapy may provide a new aspect of therapeutic angiogenesis in this patient population where expanded populations of regenerative cells might be required.

Assessment of lipid and protein peroxidation markers in non-pregnant and pregnant female dogs.

The aim of the study was to investigate oxidative stress during normal pregnancy in female dogs based on an evaluation of plasma markers for lipid and protein peroxidation. Twenty clinically healthy female dogs (10 non-pregnant and 10 pregnant) were used in the study. Blood samples from the pregnant animals were collected at 19-21, 38-40, and 56-58 days of pregnancy. Blood samples from non-pregnant female dogs were obtained between 20 and 35 days after ineffective breeding. As indicators of oxidative stress, we measured the following using spectrophotometric and spectrof- luorimetric methods: thiobarbituric acid reactive substances (TBARS), radical cations of N,N, diethylparaphenylene diamine (RC-DEPPD), sulfhydryl groups (SH groups), bityrosine and formylkynurenine. The mean plasma TBARS concentration in the pregnant dogs (0.486 ± 0.071-0.581 ± 0.191 μmol/g protein) was significantly higher (p < 0.05) than that found in the non-pregnant animals (0.274 ± 0.111 μmol/g protein). A marked, although not significant, decrease in SH group content, as well as an increase in bityrosine and formylkynurenine concentration were concurrently observed in the pregnant dogs. No significant differences were found in terms of the studied markers in the pregnant animals when comparing the values obtained during the investigated periods of pregnancy, although there was a progressive decrease in TBARS concentration and a progressive increase in RC-DEPPD, bityrosine and formylkynurenine contents. Our findings suggest that normal pregnancy in female dogs is associated with oxidative stress. Further studies are necessary to establish the physiological ranges of antioxidative/oxidative profiles in pregnant dogs and to explain if and how the intensity of oxidative stress might contribute to the risk of the complications of pregnancy.

Pancreatic β-cell dysfunction in polycystic ovary syndrome: role of hyperglycemia-induced nuclear factor-κB activation and systemic inflammation.

In polycystic ovary syndrome (PCOS), oxidative stress is implicated in the development of β-cell dysfunction. However, the role of mononuclear cell (MNC)-derived inflammation in this process is unclear. We determined the relationship between β-cell function and MNC-derived nuclear factor-κB (NF-κB) activation and tumor necrosis factor-α (TNF-α) secretion in response to a 2-h 75-g oral glucose tolerance test (OGTT) in normoglycemic women with PCOS (15 lean, 15 obese) and controls (16 lean, 14 obese). First- and second-phase β-cell function was calculated as glucose-stimulated insulin secretion (insulin/glucose area under the curve for 0-30 and 60-120 min, respectively) × insulin sensitivity (Matsuda Index derived from the OGTT). Glucose-stimulated NF-κB activation and TNF-α secretion from MNC, and fasting plasma thiobarbituric acid-reactive substances (TBARS) and high-sensitivity C-reactive protein (hs-CRP) were also assessed. In obese women with PCOS, first- and second-phase β-cell function was lower compared with lean and obese controls. Compared with lean controls, women with PCOS had greater change from baseline in NF-κB activation and TNF-α secretion, and higher plasma TBARS. β-Cell function was inversely related to NF-κB activation (1st and 2nd) and TNF-α secretion (1st), and plasma TBARS and hs-CRP (1st and 2nd). First- and second-phase β-cell function also remained independently linked to NF-κB activation after adjustment for body fat percentage and TBARS. In conclusion, β-cell dysfunction in PCOS is linked to hyperglycemia-induced NF-κB activation from MNC and systemic inflammation. These data suggest that in PCOS, inflammation may play a role in impairing insulin secretion before the development of overt hyperglycemia.

The lipid peroxidation and antioxidant status of type 2 diabetic patients in Kashmir (India)

The present study was to evaluate the redox balance in type 2 diabetes mellitus by measuring oxidative stress and antioxidant status along with lipid profile parameters in Kashmiri population. So far, no study has been undertaken on this aspect in Kashmiri population. We, therefore, aimed this maiden study in Kashmiri population to examine redox balance by measuring oxidative stress and antioxidant status along with lipid profile in 50 patients of diabetes mellitus type 2 and 30 matched normal subjects. Fifty patients of diabetes mellitus type 2 without any complications (mean age = 59.8 ± 10.4 years) and 30 normal subjects (mean age = 52.8 ± 12.8 years) were included in this study. Body mass index and waist/hip ratio was measured. Fasting blood sample was collected for the analysis of total antioxidant activity, plasma and urinary thiobarbituric acid reactive substances and lipid profile by standard procedures in both the groups. Total cholesterol, triglyceride, LDL cholesterol, plasma, and urinary thiobarbituric acid reactive substances (raised oxidative stress) were significantly raised, whereas plasma total antioxidant activity was significantly reduced in diabetes mellitus type 2 patients as compared to controls. The comparison of old and fresh cases revealed that though total antioxidant activity was lower and plasma thiobarbituric acid reactive substances and urinary thiobarbituric acid reactive substances were higher in patients, but did not attain the level of significance. W/H ratio is significantly higher in patients compared to normal subjects. But, no significant correlation of body mass index and waist/hip with lipid profile is observed in both control and patients. Raised oxidative stress in type 2 diabetes mellitus patients, along with deranged lipid profile, increased W/H ratio and decreased antioxidant activity could be the risk factors in the development of complications associated with diabetes mellitus.

Effects of ovariohysterectomy on oxidative stress markers in female dogs.

Numerous studies reported an increase of oxidative stress increases in both women and female laboratory animals after ovariectomy. However, there is little information about the evaluation of antioxidative/oxidative status in ovariectomized dogs. The purpose of this study was to examine the changes in oxidative stress markers after ovariohysterectomy (OHE) in female dogs. The study included eighteen healthy mongrel female dogs. Blood samples were collected immediately before surgery and 14 and 30days after surgery. Following parameters of oxidative stress intensity were determined: the erythrocyte activity of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) as well as the plasma concentrations of thiobarbituric acid reactive substances (TBARS), radical cations of N,N, diethylpara-phenylene diamine (RC-DEPPD), sulfhydryl groups (SH groups), bityrosine and formylkynurenine. The activity of GSH-Px increased markedly, although not significantly, 14days after OHE and then significantly decreased at 30days after OHE. A significant increase in plasma TBARS, bityrosine and formylkynurenine concentrations and a decrease in SH group content were concurrently noted at 30days after surgery. Acquired results suggested that a loss of control over ROS production occurred in female dogs after OHE, which could lead to oxidative stress in the late post-operative period. In conclusion, our findings indicated that OHE is related with the risk of oxidative stress in the late period after operations. Given that oxidative stress contributes to the pathogenesis of various diseases, this may suggest an increased risk of disorders in ovariectomized female dogs; however, further studies are necessary to confirm this hypothesis.

The impact of acute lung injury, ECMO and transfusion on oxidative stress and plasma selenium levels in an ovine model

The purpose of this study was to determine the effects of smoke induced acute lung injury (S-ALI), extracorporeal membrane oxygenation (ECMO) and transfusion on oxidative stress and plasma selenium levels. Forty ewes were divided into (i) healthy control (n=4), (ii) S-ALI control (n=7), (iii) ECMO control (n=7), (iv) S-ALI+ECMO (n=8) and (v) S-ALI+ECMO+packed red blood cell (PRBC) transfusion (n=14). Plasma thiobarbituric acid reactive substances (TBARS), selenium and glutathione peroxidase (GPx) activity were analysed at baseline, after smoke injury (or sham) and 0.25, 1, 2, 6, 7, 12 and 24h after initiation of ECMO. Peak TBARS levels were similar across all groups. Plasma selenium decreased by 54% in S-ALI sheep (1.36±0.20 to 0.63±0.27μmol/L, p<0.0001), and 72% in sheep with S-ALI+ECMO at 24h (1.36±0.20 to 0.38±0.19, p<0.0001). PRBC transfusion had no effect on TBARS, selenium levels or glutathione peroxidase activity in plasma. While ECMO independently increased TBARS in healthy sheep to levels which were similar to the S-ALI control, the addition of ECMO after S-ALI caused a negligible increase in TBARS. This suggests that the initial lung injury was the predominant feature in the TBARS response. In contrast, the addition of ECMO in S-ALI sheep exacerbated reductions in plasma selenium beyond that of S-ALI or ECMO alone. Clinical studies are needed to confirm the extent and duration of selenium loss associated with ECMO.

Increased oxidative stress in patients with 3-hydroxy-3-methylglutaric aciduria.

3-hydroxy-3-methylglutaric aciduria (HMGA; OMIM 246450) is a rare autosomal recessive disorder, caused by the deficiency of 3-hydroxy-3-methylglutaryl-CoA lyase (4.1.3.4), which results in the accumulation of3-hydroxy-3-methylglutaric (HMG) and 3-methylglutaric (MGA) acids in tissues and biological fluids of affected individuals. Recent in vivo and in vitro animal studies have demonstrated that the accumulation of these metabolites can disturb the cellular redox homeostasis, which can contribute to the neurological manifestations presented by the patients. So, in the present work, we investigated oxidative stress parameters in plasma and urine samples from HMGA patients, obtained at the moment of diagnosis of this disorder and during therapy with low-protein diet and L-carnitine supplementation. It was verified that untreated HMGA patients presented higher levels of urinary di-tyrosine and plasma thiobarbituric acid-reactive substances (TBA-RS), which are markers of protein and lipid oxidative damage, respectively, as well as a reduction of the urinary antioxidant capacity. Treated HMGA patients also presented an increased protein oxidative damage, as demonstrated by their higher concentrations of plasma protein carbonyl groups and urinary di-tyrosine, as well as by the reduction of total sulfhydryl groups in plasma, in relation to controls. On the other hand, HMGA patients under therapy presented normal levels of TBA-RS and urinary antioxidant capacity, which can be related, at least in part, to the antioxidant and antiperoxidative effects exerted by L-carnitine. The results of this work are the first report showing that a redox imbalance occurs in patients with HMGA what reinforces the importance of the antioxidant therapy in this disorder.

Evaluation of antidiabetic, hypolipedimic and antioxidant activity of hydroalcoholic extract of leaves and fruit peel of Punica granatum in male Wistar albino rats.

Background:We investigated anti-diabetic, hypolipedimic and antioxidant activity of hydroalcoholic extract from leaves and fruit peel of Punica granatum.Materials and Methods:Streptozotocin induced diabetic Wister rats were used in this study consisting of seven groups of six animals each. Groups (1) normal control, (2) diabetic control, (3) leaves extract 100 mg/kg b.w. of P. granatum, (4) leaves extract 200 mg/kg b.w. of P. granatum, (5) fruit peel extract 100 mg/kg b.w. of P. granatum, (6) peel extract 200 mg/kg b.w. of P. granatum and (7) glibenclamide respectively. Fasting blood sugar was recorded on 1st, 7th, 14th, 21st and 28th day. At the end of the experiment Lipid profile and levels of antioxidants were determined. Safety profile of both extracts was evaluated using acute and chronic toxicity studies.Results:Higher dose of fruit peel extract of P. granatum (PEPG) and glibenclamide significantly lowered blood glucose level from 7th day onwards however glibenclamide was found to be more effective. Leaves extract at higher dose and fruit extract at lower dose also significantly lowered blood glucose level from 14th day onwards. Leaves extract at lower dose also significantly lowered blood glucose level from 21st day onwards. Glibenclamide and higher dose of fruit PEPG extract significantly reduced the total cholesterol, triglyceride levels and significantly increased the high density lipoprotein cholesterol level. Glibenclamide followed by higher dose was found more effective in reducing plasma thiobarbituric acid reactive substances and increasing levels of antioxidant enzymes (superoxide dismutase and catalase). No toxicity was observed even when both extracts were administered at 10 times of higher dose used in this study and no significant changes were seen when it were used chronically.Conclusion:Leaves and fruit PEPG possesses significant anti-diabetic, hypolipedimic and antioxidant properties. This study supports the traditional use of P. granatum in diabetes. Fruit peel which is normally thrown by many while eating pomegranate fruit is having anti-diabetic, hypolipedimic and Antioxidant activity. Furthermore high therapeutic index is safe for chronic use.

The Role of Matricaria recutita L. and Asparagus officinalis L. against the Neurotoxicity of Diazinon in Rats

Diazinon (DZN) is an organophosphate insecticide used mainly in agriculture and in sheep dips, and is designed as an irreversible acetylcholine esterase inhibitor [1,2]. It is classified as moderately hazardous class-II organophosphate insecticide [3]. Many systems could be affected by organophosphate intoxication are the immune system, urinary system, reproductive system, pancreas and haematological and biochemical changes [4-8]. In addition, showed that neonatal DZN exposure, at doses below the threshold for cholinesterase inhibition has been lasting effects on emotional responses, with preferential effects on males [9,10]. The microsomal enzymes in the liver oxidize DZN are generating more potent acetylcholinesterase inhibitors, such as diazoxon, hydroxydiazoxon and hydroxydiazinon [11]. Diazinon affects mitochondrial membrane transportation in rat liver [12]. Moreover, it interrupts cytochrome P450 system in human liver [13]. Oxidative stress can also be induced by pesticides, either by the overproduction of free radicals or by alteration in antioxidant defence mechanisms, including detoxification and scavenging enzymes [14]. Oxidative stress has been reported to play an important role in the toxicity of various pesticides, including organochlorines, carbamates and pyrethrods [15,16]. The higher oxidative stress in pesticide sprayers is evidenced by increased concentration of plasma and red blood cell thiobarbituric acid reactive substances (TBARS), changes in antioxidant status, and altered activities of cellular enzymes [17]. Treatment of rats with DZN significantly enhances renal lipid peroxidation, which is accompanied by a decrease in the activities of renal antioxidant enzymes (e.g. catalase (CAT), glutathione peroxidise, glutathione reductase (GSH-R), glucose- 6-phosphate dehydrogenase, glutathione-s-transferase (GST) and depletion in the level of glutathione reduced (GSH). In blood, normal erythrocyte function depends on the intactness of cell membrane, which is the target for many toxic factors, including pesticides. Erythrocyte GSH together with glutathione peroxidase (GSH-Px), GSH-R, GST, gamma-glutamyl transferase (γ-GT), superoxide dismutase (SOD) and CAT efficiently scavenge toxic free radicals and are partly responsible for protecting against lipid peroxidation due to acute/chronic pesticide exposure [18]. There is a relationship between pesticide exposure and the decrease of antioxidant enzymes [19]. Oxidative stress and genotoxic effects of DZN were documented through the changes in total antioxidant capacity (TAC), reduced GSH and oxidative DNA damage [20]. Exposure to low-level of pesticides is known to produce a variety of biochemical and molecular changes, some of which may be responsible for the adverse biological effects reported in human and experimental studies. Many studies have reported that DZN can induce molecular changes and alter gene expression. Jamshidi et al. have found that administration of DZN to rats at doses of 60 mg/ kg significantly decreased expression of glutamate dehydrogenase, the key enzyme of Langerhans islet for the secretion of insulin, gene 18- hour post-administration [21]. Other studies showed that DZN had affected the expression of neurotrophic factors that coordinate neuronal cell differentiation and brain assembly [22]. In addition, Timofeeva et al. found that persisting effect of developmental DZN cholinergic and serotonergic neurotransmitter systems and gene expression as well as behavioural function [9]. Matricaria recutita L. (family Asteraceae, commonly known as German chamomile) is one of the most widely used and welldocumented medicinal plants in the world [23]. Chamomile is also

Evaluation of the Anti-oxidant Effet of Spirulina on Marathon Runners in Cote D’ivoire

This experimental intervention research, of the BEFORE-AFTER TYPE was conducted on a sample of ten marathon runners and was undertaken in two sessions of half-marathon separated by a 15-day interval. During this period, each marathon runner took in 5400 mg per day of Spirulina - a microscopic Cyanobacteria-seaweed that is rich in antioxidant substances. Their oxidative stress was assessed before and after each race with and without Spirulina intake using a spectrofluorometric measurement of the Thiobarbituric Acid Reactive Substances (TBARS), according to the Yagi method as modified by Sess. The results were as follows: • Race without Spirulina intake: TBARS before the race: 1.48 ± 0.631 nmol of malondialdehyde (MDA) per mL of plasma TBARS after the race: 2.96 ± 0.733 nmol of MDA per mL of plasma • Race with Spirulina intake: TBARS before the race: 0.66 ± 0.508 nmol of MDA per mL of plasma TBARS after the race: 1.46 ± 0.488 nmol of MDA per mL of plasma. We observed that the levels of secondary oxidation were reduced by half with the intake of Spirulina, a reduction that is significant at rest (p=0.027) as well as after the physical effort (p=0.001). At the hemodynamic and anthropometric levels, it was observed that the intake of Spirulina led to a significant increase in weight (65.96 Kg ± 4.16 v 65.49 Kg ± 4.16; p<0.01) and in arterial systolic blood pressure (12.8 mmHg ± 1.13 v 11.4 mmHg ± 0.51; p<0.01). Our results are supportive of the prescription of Spirulina in most pathological cases, in view of the implication of free radicals in pathogenic life cycles. This would translate into considerable public health benefits.

Ethanol withdrawal increases oxidative stress and reduces nitric oxide bioavailability in the vasculature of rats

We analyzed the effects of ethanol withdrawal on the vascular and systemic renin-angiotensin system (RAS) and vascular oxidative stress. Male Wistar rats were treated with ethanol 3–9% (v/v) for a period of 21 days. Ethanol withdrawal was induced by abrupt discontinuation of the treatment. Experiments were performed 48 h after ethanol discontinuation. Rats from the ethanol withdrawal group showed decreased exploration of the open arms of the elevated-plus maze (EPM) and increased plasma corticosterone levels. Ethanol withdrawal significantly increased systolic blood pressure and plasma angiotensin II (ANG II) levels without an effect on plasma renin activity (PRA), angiotensin converting enzyme (ACE) activity, or plasma angiotensin I (ANG I) levels. No differences in vascular ANG I, ANG II levels, and ACE activity/expression and AT1 and AT2 receptor expression were detected among the experimental groups. Plasma osmolality, as well as plasma sodium, potassium, and glucose levels were not affected by ethanol withdrawal. Ethanol withdrawal induced systemic and vascular oxidative stress, as evidenced by increased plasma thiobarbituric acid-reacting substances (TBARS) levels and the vascular generation of superoxide anion. Ethanol withdrawal significantly decreased plasma and vascular nitrate/nitrite levels. Major new findings of the present study are that ethanol withdrawal induces vascular oxidative stress and reduces nitric oxide (NO) levels in the vasculature. Additionally, our study provides novel evidence that ethanol withdrawal does not affect the vascular ANG II generating system while stimulating systemic RAS. These responses could predispose individuals to the development of cardiovascular diseases.

Vascular injury in diabetic db/db mice is ameliorated by atorvastatin: role of Rac1/2-sensitive Nox-dependent pathways.

Oxidative stress [increased bioavailability of reactive oxygen species (ROS)] plays a role in the endothelial dysfunction and vascular inflammation, which underlie vascular damage in diabetes. Statins are cholesterol-lowering drugs that are vasoprotective in diabetes through unknown mechanisms. We tested the hypothesis that atorvastatin decreases NADPH oxidase (Nox)-derived ROS generation and associated vascular injury in diabetes. Lepr(db)/Lepr(db) (db/db) mice, a model of Type 2 diabetes and control Lepr(db)/Lepr(+) (db/+) mice were administered atorvastatin (10 mg/kg per day, 2 weeks). Atorvastatin improved glucose tolerance in db/db mice. Systemic and vascular oxidative stress in db/db mice, characterized by increased plasma TBARS (thiobarbituric acid-reactive substances) levels and exaggerated vascular Nox-derived ROS generation respectively, were inhibited by atorvastatin. Cytosol-to-membrane translocation of the Nox regulatory subunit p47(phox) and the small GTPase Rac1/2 was increased in vessels from db/db mice compared with db/+ mice, an effect blunted by atorvastatin. The increase in vascular Nox1/2/4 expression and increased phosphorylation of redox-sensitive mitogen-activated protein kinases (MAPKs) was abrogated by atorvastatin in db/db mice. Pro-inflammatory signalling (decreased IκB-α and increased NF-κB p50 expression, increased NF-κB p65 phosphorylation) and associated vascular inflammation [vascular cell adhesion molecule-1 (VCAM-1) expression and vascular monocyte adhesion], which were increased in aortas of db/db mice, were blunted by atorvastatin. Impaired acetylcholine (Ach)- and insulin (INS)-induced vasorelaxation in db/db mice was normalized by atorvastatin. Our results demonstrate that, in diabetic mice, atorvastatin decreases vascular oxidative stress and inflammation and ameliorates vascular injury through processes involving decreased activation of Rac1/2 and Nox. These findings elucidate redox-sensitive and Rac1/2-dependent mechanisms whereby statins protect against vascular injury in diabetes.

Influence of magnesium on biochemical parameters of iron and oxidative stress in patients with type 2 diabetes.

Studies have shown that oxidative stress, found in patients with type 2 diabetes, may be due to changes in the metabolism of minerals, such as magnesium and iron. Data related to compartmentalization of these minerals in diabetes are scarce and controversial. This study assessed the influence of magnesium on biochemical parameters of iron and oxidative stress in patients with type 2 diabetes. A case-control study in male and female subjects aged 27-59 years, divided into two groups: type 2 diabetes (n=40) and control (n=48). Intake of magnesium and iron was assessed by three-day food record. Plasma, erythrocyte and urinary levels of magnesium, serum iron, ferritin, total iron binding capacity, fasting glucose, glycated hemoglobin, insulin, creatinine clearance and plasma thiobarbituric acid reactive substances (TBARS) were analyzed. Magnesium intake and plasma magnesium were lower in diabetic subjects. There was low urinary magnesium excretion, with no difference between groups. Although normal, the diabetic group had lower serum iron and ferritin concentrations compared to control subjects. Plasma TBARS in diabetic patients was higher than control while creatinine clearance was lower. An inverse correlation between erythrocyte magnesium and serum iron and ferritin was observed in the diabetes group. Diabetes induced hypomagnesemia and this, associated with chronic hyperglycemia, may have enhanced oxidative stress. Erythrocyte magnesium may have contributed to prevent iron overload and worsening of oxidative stress and hyperglycemic status.

The role of obesity in the immune response during sepsis.

Background/Objectives:Sepsis is one of the most important causes of mortality in the developed world, where almost two-thirds of the population suffer from obesity. Therefore, the coexistence of both conditions has become frequent in clinical practice and a growing number of clinical studies attempts to examine the potential effect of obesity on sepsis with controversial results up to now. The present study investigates how obesity influences the immune response of septic patients, by assessing the number and activation state of adipose tissue macrophages, serum and adipose tissue tumor necrosis factor-alpha (TNFα) levels and plasma oxidative stress markers.Subjects/methods:The study included 106 patients, divided into four groups (control n=26, obesity n=27, sepsis n=27 and sepsis and obesity n=26). The number of macrophages in subcutaneous and visceral adipose tissue (SAT and VAT) and their subtypes (M1 and M2) were defined with immunohistochemical staining techniques under light microscopy. TNFα mRNA levels were determined in SAT and VAT using real-time reverse transcription-PCR. Serum levels of TNFα were determined with sandwich enzyme-linked immunosorbent assay. Plasma oxidative stress was evaluated using selective biomarkers (thiobarbituric acid-reactive substances (TBARS), protein carbonyls and total antioxidant capacity (TAC)).Results:Sepsis increased the total number of macrophages and their M2 subtype in (VAT), whereas obesity did not seem to affect the concentration of macrophages in fat. Obesity increased TNFα mRNA levels (P<0.05) in VAT as well as the plasma TBARS (P<0.001) and protein carbonyls (P<0.001) in septic patients. The plasma TAC levels were decreased and the serum TNFα levels were increased in sepsis although they were not influenced by obesity.Conclusions:Obesity is associated with elevated TNFα adipose tissue production and increased oxidative stress biomarkers, promoting the proinflammatory response in septic patients.

Markers of inflammation and oxidative stress studied in adjuvant-induced arthritis in the rat on systemic and local level affected by pinosylvin and methotrexate and their combination

Oxidative stress (OS) is important in the pathogenesis of autoimmune diseases such as rheumatoid arthritis (RA) and its experimental model – adjuvant arthritis (AA). Antioxidants are scarcely studied in autoimmunity, and future analyses are needed to assess its effects in ameliorating these diseases. Although there are studies about antioxidants effects on the course of RA, their role in combination therapy has not yet been studied in detail, especially on extra-articular manifestations of AA. During the 28-d administration of pinosylvin (PIN) in monotherapy and in combination with methotrexate (MTX) to AA rats, we evaluated the impact of the treatment on selected parameters. The experiment included: healthy controls, untreated AA, AA administered 50 mg/kg b.w. of PIN daily p.o., AA administered 0.4 mg/kg b.w. of MTX twice weekly p.o. and AA treated with a combination of PIN+MTX. AA was monitored using: hind paw volume, C-reactive protein, monocyte chemotactic protein-1 (MCP-1), thiobarbituric acid reactive substances (TBARS) and F2-isoprostanes in plasma, γ-glutamyltransferase activity in spleen, activity of lipoxygenase (LOX) in lung, heme oxygenase-1 (HO-1) and nuclear factor kappa B (NF-κB) in liver and lung. PIN monotherapy significantly improved the activation of NF-κB in liver and lung, HO-1 expression and activity of LOX in the lung, MCP-1 levels in plasma (on 14th d) and plasmatic levels of F2-isoprostanes. An important contribution of PIN to MTX effect was the reduction of OS (an increase of HO-1 expression in lung and reduction of plasmatic TBARS) and decrease of LOX activity in the lung.

Modulation of antioxidant status in streptozotocin-induced diabetic male wistar rats following intake of red palm oil and/or rooibos

ObjectiveTo investigate the role of red palm oil (RPO), rooibos tea extract (RTE) and their combined treatment (RPO + RTE) on antioxidant status in streptozotocin (STZ)-induced diabetic rats. MethodsDiabetes mellitus was induced by a single administration of streptozotocin (50 mg/kg) and the rats were treated for 7 weeks. Antioxidant enzymes [catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD)], antioxidant capacity [trolox equivalence antioxidant capacity (TEAC), oxygen radical absorbance capacity (ORAC)] as well as total protein, albumin, globulin, total glutathione, conjugated diene and thiobarbituric acid reactive substances (TBARS) were investigated. ResultsTreatment with RPO, RTE and RPO + RTE significantly (p>0.05) improved liver SOD and plasma ORAC in the diabetic rats. Similarly, diabetic rats treated with RTE and RPO + RTE enhanced liver GPx. A significant (P<0.05) increase in the plasma TBARS in the diabetic control group was observed when compared with the normal control group. Treatment of diabetic rats with RTE and RPO + RTE reduced plasma TBARS to a level not significantly different at P<0.05 from the normal control group. ConclusionsThe results revealed the anti-oxidative potentials of red palm oil, rooibos and their combination in diabetic conditions and hence, they could be useful in the management of diabetes and its complications.

Effect of N-acetylcysteine on Cycling Performance after Intensified Training

This investigation examined the ergogenic effect of short-term oral N-acetylcysteine (NAC) supplementation and the associated changes in redox balance and inflammation during intense training. A double-blind randomized placebo-controlled crossover design was used to assess 9 d of oral NAC supplementation (1200 mg·d) in 10 well-trained triathletes. For each supplement trial (NAC and placebo), baseline venous blood and urine samples were taken, and a presupplementation cycle ergometer race simulation was performed. After the loading period, further samples were collected preexercise, postexercise, and 2 and 24 h after the postsupplementation cycle ergometer race simulation. Changes in total antioxidant capacity, ferric reducing ability of plasma, reduced glutathione, oxidized glutathione, thiobarbituric acid-reactive substances, interleukin 6, xanthine oxidase, hypoxanthine, monocyte chemotactic protein 1, nuclear factor κB, and urinary 15-isoprostane F2t concentration were assessed. The experimental procedure was repeated with the remaining supplement after a 3-wk washout. Eight participants completed both supplementation trials. NAC improved sprint performance during the cycle ergometer race simulation (P < 0.001, ηp = 0.03). Supplementation with NAC also augmented postexercise plasma total antioxidant capacity (P = 0.005, ηp = 0.19), reduced exercise-induced oxidative damage (plasma thiobarbituric acid-reactive substances, P = 0.002, ηp = 0.22; urinary 15-isoprostane F2t concentration, P = 0.010, ηp = 0.431), attenuated inflammation (plasma interleukin 6, P = 0.002, ηp = 0.22; monocyte chemotactic protein 1, P = 0.012, ηp = 0.17), and increased postexercise nuclear factor κB activity (P < 0.001, ηp = 0.21). Oral NAC supplementation improved cycling performance via an improved redox balance and promoted adaptive processes in well-trained athletes undergoing strenuous physical training.