Superoxide dismutases and their impact upon human health

Proteomic profiling of dog urine after European adder (Vipera berus berus) envenomation by two-dimensional difference gel electrophoresis

Between April and September every year, many dogs in Finland are bitten by Vipera berus berus, also known as the European adder, the only venomous snake in the area. Exposure to snake bite venom causes local and systemic symptoms and in severe cases can lead to death. Urine samples were collected from four dogs bitten by V. berus berus and treated in the intensive care unit of the Veterinary Teaching Hospital at the University of Helsinki. The inclusion criteria were a strong suspicion of an adder bite no more than two days before admission and clinical signs of an adder bite. Exclusion criteria were defined as ongoing treatment with glucocorticoids or a known history of liver or kidney diseases. Six privately owned, healthy dogs were obtained as controls. Samples were subjected to 2D-DIGE analysis. Image analysis was performed with DeCyder 7.0 2D software, and protein spots demonstrating a minimum 1.5-fold difference in average spot volume ratios between envenomed and control dogs with a Student's t-test p-value of less than 0.05 were picked and identified using LC-MS/MS. In 2D-DIGE analysis, seven proteins were significantly (p < 0.05) over-expressed in the urine of dogs bitten by V. berus berus compared to the control group. From these, five proteins were identified: beta-2-microglobulin (b2MG), alpha-1-antitrypsin (AAT), albumin, fetuin-B and superoxide dismutase (SOD1). Results indicate that envenomation by V. berus berus alter the urinary protein profile in dogs.

Evaluation of serum oxidant/antioxidant balance in multiple sclerosis

The total oxidative status (TOS)/total anti-oxidative status (TAS) ratio can provide information on an individual's absolute oxidative stress index (OSI). We investigated the alterations in the oxidant-antioxidant balance by measuring the oxidant parameters OSI, TOS, and malondialdehyde (MDA) together with the antioxidant parameters such as TAS, and superoxide dismutase (SOD) in patients with relapsing remitting multiple sclerosis (MS). To our knowledge, this is the first study to evaluate OSI in patients with relapsing remitting MS. 35 ambulatory patients with relapsing-remitting MS (35.8 ± 8.7 years) and 32 age- and activity-matched healthy control subjects (35.1 ± 3.7 years) that participated in the study. Serum TAS and TOS levels were determined using new automated methods. MS patients had higher concentrations of MDA (151.5 ± 51.1 vs. 111.3 ± 27.4 nmol/g protein, respectively; p < 0.001), TOS (148.1 ± 162.5 vs. 48.3 ± 46.4 mmol H(2)O(2) Equiv./g protein, respectively; p = 0.002), OSI (21124 ± 32543 vs. 5294 ± 5562, respectively; p = 0.008), and SOD (4.5 ± 0.7 vs. 3.4 ± 0.6 U/L, respectively; p < 0.001) compared with healthy controls. On the other hand, MS patients had lower concentrations of NO (12.3 ± 6.9 vs. 17.4 ± 2.5 μmol/g protein, respectively; p < 0.001) and TAS (0.82 ± 0.27 vs. 0.26 ± 0.15, respectively; p = 0.011) compared with healthy controls. In conclusion, these findings indicate that the oxidative stress plays an important role in the pathogenesis of MS.

Upregulation of superoxide dismutase activity in the intestinal tract mucosa of germ-free mice

Superoxide dismutase (SOD) catalyzes the breakdown of superoxide into hydrogen peroxide and oxygen in the antioxidant defense system. We had reported that the SOD activities in the ceca of germ-free (GF) mice were significantly higher than those in conventional (CV) mice. In this study, we confirmed the location where SOD activity and protein expression increased in the ceca of GF mice. An immunohistochemical analysis and total SOD activity assay were conducted using the mucosa and other remaining tissues in the ceca. In addition to SOD activity in the ceca, 4 sites of intestinal (duodenal, jejunal, ileal and colonic) mucosae in GF mice were compared with those of CV mice. Total SOD activity in the cecal mucosa of GF mice was significantly higher than that in CV mice (P<0.01), and the intensity of CuZnSOD-positive cells in cecal mucosa was increased in all GF mice. Total and CuZnSOD activities in the duodenal, jejunal, ileal, cecal and colonic mucosae of GF mice were significantly higher than those in CV mice (P<0.05, or P<0.01). Furthermore, CuZnSOD mRNA showed similar tendencies with respect to these activities. Our results suggest for the first time that upregulation of SOD activity occurs in the entire intestinal mucosa of GF mice.

Age-related oxidative stress compromises endosomal proteostasis

A hallmark of aging is an imbalance between production and clearance of reactive oxygen species and increased levels of oxidatively damaged biomolecules. Herein, we demonstrate that splenic and nodal antigen-presenting cells purified from aging mice accumulate oxidatively modified proteins with side-chain carbonylation, advanced glycation end products, and lipid peroxidation. Furthermore, we show that the endosomal accumulation of oxidatively modified proteins interferes with the efficient processing of exogenous antigens and degradation of macroautophagy-delivered proteins. In support of a causative role for oxidized products in the inefficient immune response, a decrease in oxidative stress improved the adaptive immune response to immunizing antigens. These findings underscore a previously unrecognized negative effect of age-dependent changes in cellular proteostasis on the immune response.

Oxidant stress and skeletal muscle microvasculopathy in the metabolic syndrome

The evolution of the metabolic syndrome in afflicted individuals is, in part, characterized by the development of a severely pro-oxidant state within the vasculature. It has been previously demonstrated by many investigators that this increasingly pro-oxidant state can have severe negative implications for many relevant processes within the vasculature, including the coordination of dilator/constrictor tone or reactivity, the structural adaptations of the vascular wall or distal networks, as well as the integrated regulation of perfusion resistance across and throughout the vascular networks. The purpose of this review article is to present the different sources of oxidant stress within the setting of the metabolic syndrome, the available mechanism for attempts at regulation and the vascular outcomes associated with this condition. It is anticipated that this overview will help readers and investigators to more effectively design experiments and interpret their results within the extremely complicated setting of metabolic syndrome.

Clinical value of decreased superoxide dismutase 1 in patients with epilepsy

PURPOSE

Our previous study using proteomic analysis showed that superoxide dismutase 1 (SOD1) was significantly decreased in cerebrospinal fluid (CSF) of patients with epilepsy. However, the relevance of CSF-SOD1 alterations for the pathophysiology of epilepsy is currently unknown. The present study was intended to add to our understanding of this issue by measuring SOD1 levels in the CSF of patients with resistant epilepsy and non-resistant epilepsy.

METHODS

A total of 52 patients with epilepsy were recruited. 29 were non-resistant, 23 drug-resistant. 20 individuals with no evidence of any neurological diseases were used as control. The concentration of CSF and serum SOD1 was measured by enzyme-linked immunosorbent assay.

RESULTS

The concentration of CSF-SOD1 was decreased in both the drug-resistant (0.13 ± 0.12 ng/ml) and the non-resistant epilepsy subgroups (0.29 ± 0.23 ng/ml) compared to the control group (0.40 ± 0.35 ng/ml). SOD1 was significantly lower in the drug-resistant than the non-resistant epilepsy subgroup (P<0.05).

CONCLUSION

SOD1 levels are decreased in the CSF of patients with epilepsy, especially of patients with intractable epilepsy. Low CSF-SOD1 levels may be a predictor of antiepileptic drug resistance in patients with epilepsy.

Dexmedetomidine protects against lipid peroxidation and erythrocyte deformability alterations in experimental hepatic ischemia reperfusion injury

Background

Hepatic ischemia–reperfusion injury is a common clinical problem in hepatic surgery and transplantation. Several cellular and tissue structural and functional alterations are observed in such injury. The aim of this study was to evaluate the effect of dexmedetomidine on lipid peroxidation and erythrocyte deformability during ischemia–reperfusion injury in rats.

Methods

Twenty-four Wistar Albino rats were randomly separated into three groups as control (C), ischemia–reperfusion injury (I/R) and dexmedetomidine group (I/R-D). Ischemia was induced with portal clampage for 45 min and reperfusion period was 45 min after declampage. Group I/R-D received dexmedetomidine 100 µg/kg i.p. 30 min before portal clampage. Serum malondialdehyde and superoxide dismutase activities to document lipid peroxidation and erythrocyte deformability index were investigated.

Results

Serum superoxide dismutase and malondialdehyde activity levels were significantly higher and erythrocyte deformability index was decreased in hepatic ischemia–reperfusion group. However, these changes were observed to be prevented with dexmedetomidine treatment when given before portal clampage.

Conclusion

These findings clearly indicate that erythrocyte deformability index is decreased in hepatic ischemia reperfusion injury and has a potential role to prevent these alterations. The protective effect of dexmedetomidine on hepatic I/R injury is also decreased lipid peroxidation. Further experimental and clinical investigations may clarify the molecular mechanisms and clinical significance of these findings.

The role of selenium in inflammation and immunity: from molecular mechanisms to therapeutic opportunities

Dietary selenium (]Se), mainly through its incorporation into selenoproteins, plays an important role in inflammation and immunity. Adequate levels of Se are important for initiating immunity, but they are also involved in regulating excessive immune responses and chronic inflammation. Evidence has emerged regarding roles for individual selenoproteins in regulating inflammation and immunity, and this has provided important insight into mechanisms by which Se influences these processes. Se deficiency has long been recognized to negatively impact immune cells during activation, differentiation, and proliferation. This is related to increased oxidative stress, but additional functions such as protein folding and calcium flux may also be impaired in immune cells under Se deficient conditions. Supplementing diets with above-adequate levels of Se can also impinge on immune cell function, with some types of inflammation and immunity particularly affected and sexually dimorphic effects of Se levels in some cases. In this comprehensive article, the roles of Se and individual selenoproteins in regulating immune cell signaling and function are discussed. Particular emphasis is given to how Se and selenoproteins are linked to redox signaling, oxidative burst, calcium flux, and the subsequent effector functions of immune cells. Data obtained from cell culture and animal models are reviewed and compared with those involving human physiology and pathophysiology, including the effects of Se levels on inflammatory or immune-related diseases including anti-viral immunity, autoimmunity, sepsis, allergic asthma, and chronic inflammatory disorders. Finally, the benefits and potential adverse effects of intervention with Se supplementation for various inflammatory or immune disorders are discussed.

Effect of nonylphenol on male reproduction: analysis of rat epididymal biochemical markers and antioxidant defense enzymes

The mechanism by which nonylphenol (NP) interferes with male reproduction is not fully elucidated. Therefore, the present study was conducted to evaluate the effect of NP on male reproductive organ's weight, sperm characteristics, and to elucidate the nature and mechanism of action of NP on the epididymis. Adult male Wistar rats were gavaged with NP, dissolved in corn oil, at 0, 100, 200 or 300mg/kg/day for 30 consecutive days. Control rats were gavaged with vehicle (corn oil) alone. Body weight did not show any significant change while, absolute testes and epididymides weights were significantly decreased. Sperm count in cauda and caput/corpus epididymides, and sperm motility was significantly decreased. Daily sperm production was significantly decreased in a dose-related manner. Sperm transit time in cauda epididymis was significantly decreased by 300mg/kg, while in the caput/corpus epididymis it was significantly decreased by 200 and 300mg/kg of NP. Plasma LDH was significantly increased while; plasma testosterone was significantly decreased in a dose-related pattern. In the epididymal sperm, NP decreased acrosome integrity, Δψm and 5'-nucleotidase activity. Hydrogen peroxide (H(2)O(2)) production and LPO were significantly increased in a dose-related pattern. The activities of SOD, CAT and GPx were significantly decreased in the epididymal sperm. In conclusion, this study revealed that NP treatment impairs spermatogenesis and has a cytotoxic effect on epididymal sperm. It disrupts the prooxidant and antioxidant balance. This leads oxidative stress in epididymal sperms of rat. Moreover, the reduction in sperm transit time may affect sperm quality and fertility potential.

Time- and dose-dependent differential regulation of copper-zinc superoxide dismutase and manganese superoxide dismutase enzymatic activity and mRNA level by vitamin E in rat blood cells

BACKGROUND

Vitamin E is the most important lipid-soluble antioxidant. Recently, it has been proposed as a gene regulator, and its gene modulation effects have been observed at different levels of gene expression and cell signaling. This study was performed to investigate the effects of vitamin E on the activity and expression of the most important endogenous antioxidant enzyme, superoxide dismutase (SOD), in rat plasma.

METHODS

Twenty-eight male Sprauge-Dawley rats were divided into four groups: control group and three dosing groups. The control group received the vehicle (liquid paraffin), and the dosing groups received twice-weekly intraperitoneal injections of 10, 30, and 100 mg/kg of vitamin E ((±)-α-Tocopherol) for 6 weeks. Quantitative real-time reverse transcription-polymerase chain reaction and enzyme assays were used to assess the levels of Cu/Zn-SOD and Mn-SOD mRNA and enzyme activity levels in blood cells at 0, 2, 4, and 6 weeks following vitamin E administration. Catalase enzyme activity and total antioxidant capacity were also assessed in plasma at the same time intervals.

RESULTS

Mn-SOD activity was significantly increased in the 100 and 30 mg/kg dosing groups after 4 and 6 weeks, with corresponding significant increase in their mRNA levels. Cu/Zn-SOD activity was not significantly changed in response to vitamin E administration at any time points, whereas Cu/Zn-SOD mRNA levels were significantly increased after longer time points with high doses (30 and 100 mg/kg) of vitamin E. Catalase enzyme activity was transiently but significantly increased after 4 weeks of vitamin E treatment in 30 and 100 mg/kg dosing groups. Total antioxidant status was significantly increased after 4 and 6 weeks in the 100 mg/kg dosing group.

CONCLUSION

Only the chronic administration of higher doses of alpha-tocopherol is associated with the increased activity and expression of Mn-SOD in rats. Cu/Zn-SOD activity and expression does not dramatically change in response to vitamin E.

Persistent oxidative stress in patients with chronic active hepatitis-C infection after antiviral therapy failure

BACKGROUND/AIMS

Oxidative stress and hepatocellular pathological changes are common associations with chronic hepatitis C virus (CHC) disease. The aim of this study was to assess serum antioxidant-oxidant (Redox) balance in patients with CHC infection before and after intake of the traditional antiviral therapy (pegylated interferon α-2b and oral ribavirin).

PATIENTS AND METHODS

Blood samples from 50 biopsy-proven CHC patients, with no prior anti-viral treatment and persistently elevated serum transaminase levels for 6 months, as well as 15 age- and sex-matched healthy subjects were used for determination of the antioxidants: reduced glutathione (GSH), superoxide dismutase (SOD), α tocopherol and ascorbic acid as well as lipid peroxidation (LPO) index (malondialdehyde [MDA]). The measurements were repeated in the diseased group 25 weeks after pegylated interferon α-2b and ribavirin combination therapy.

RESULTS

Serum levels of bilirubin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were significantly higher in CHC patients than in the control group (P < 0.05). Pretreatment serum MDA values were significantly higher in patients with CHC infection than the control group (P < 0.001), while serum antioxidant levels were significantly lower (P < 0.001). Responders (10 patients) had lower pretreatment serum levels of MDA than non-responders (35 patients) (P < 0.001). Both groups were comparable for the antioxidant serum levels. There was significant negative correlation between serum MDA and serum SOD, GSH, α tocopherol, and ascorbic acid concentrations in CHC patients. On the other hand, there was no correlation between the studied parameters and serum bilirubin, albumin, ALT, and AST.

CONCLUSIONS

Redox imbalance was detected in patients with CHC. Responders had significantly lower levels of MDA than non-responders. Serum MDA may be used as a pretreatment predictor of response to antiviral treatment in patients with CHC.

Encapsulation of cardiac stem cells in superoxide dismutase-loaded alginate prevents doxorubicin-mediated toxicity

Anthracyclines are powerful drugs available for the treatment of neoplastic diseases. Unfortunately, these chemotherapy agents cause cardiomyopathy and congestive heart failure. Doxorubicin (DOX) is a widely used anthracycline and evidence indicates that DOX-induced cardiotoxicity can be viewed as a stem cell disease, whereby the formation of reactive oxygen species (ROS) by DOX is seen to predominantly hinder cardiac stem cell (CSC) regenerative capability. Acute, early-onset and late-onset cardiotoxicity have been described and this may be reversible by the local administration of CSCs, which regenerate myocardial tissue and rescue the failing heart. CSCs are, however, particularly sensitive to oxidative stress and die rapidly by apoptosis in such adverse conditions. Therefore, this study aims to enhance CSC survival by encapsulation in an alginate hydrogel formulation containing superoxide dismutase (SOD), a reactive oxygen species scavenger. Cell survival was qualitatively and quantitatively assessed by fluorescent microscopy and assays measuring metabolic activity, cell viability, cytotoxicity and apoptosis. CSCs were cultured in DOX-conditioned cell culture medium and displayed reduced live cell numbers as well as high levels of apoptosis. Encapsulation of CSCs in alginate alone failed to prevent apoptosis. Encapsulation in SOD-loaded alginate reduced apoptosis to near-normal levels, whilst metabolic activity was returned to baseline. In conclusion, this study demonstrates that encapsulation of CSCs in SOD-loaded alginate hydrogel enhances CSC survival in the presence of DOX, raising the possibility of its application as a novel therapy for the treatment of acute and early onset DOX-induced cardiotoxicity.

Antioxidant defenses in the ocular surface

The human eye is subjected constantly to oxidative stress due to daily exposure to sunlight, high metabolic activities, and oxygen tension. Reactive oxygen species generated from environmental insults and pathological conditions render the human eye particularly vulnerable to oxidative damage. The ocular surface composed of the tear film, the cornea, and the aqueous humor forms the first physical and biochemical barrier of the eye and plays a pivotal role in combating free radicals. These ocular compartments are enriched in certain antioxidants in the form of metabolic enzymes or small molecules. Such an antioxidant defense system in the ocular surface is essential for the maintenance of redox homeostasis in the eye and protection against oxidative damage. Herein, we review the properties and functions of key constituent antioxidants of the ocular surface.

Ultraviolet radiation: cellular antioxidant response and the role of ocular aldehyde dehydrogenase enzymes

Solar ultraviolet radiation (UVR) exposes the human eye to near constant oxidative stress. Evidence suggests that UVR is the most important environmental insult leading to the development of a variety of ophthalmoheliosis disorders. UVR-induced reactive oxygen species (ROS) are highly reactive with DNA, proteins, and cellular membranes, resulting in cellular and tissue damage. Antioxidant defense systems present in ocular tissues function to combat ROS and protect the eye from oxidative damage. Important enzymatic antioxidants are the superoxide dismutases, catalase, glutathione peroxidases, glutathione reductase, and members of the aldehyde dehydrogenase (ALDH) superfamily. Glutathione, ascorbic and uric acids, α-tocopherol, nicotinamide-adenine dinucleotide phosphate, and ferritin serve as small molecule, nonenzymatic antioxidants. Ocular tissues have high levels of these antioxidants, which are essential for the maintenance of reduction-oxidation homeostasis in the eye and protection against oxidative damage. ALDH1A1 and ALDH3A1, present abundantly in the cornea and lens, have been shown to have unique roles in the defense against UVR and the downstream effects of oxidative stress. This review presents the properties and functions of ocular antioxidants that play critical roles in the cellular response to UVR exposure, including a focused discussion of the unique roles that the ALDH1A1 and ALDH3A1 enzymes have as multifunctional ocular antioxidants.

Redox control of the survival of healthy and diseased cells

Abstract Cellular redox homeostasis is the first line of defense against diverse stimuli and is crucial for various biological processes. Reactive oxygen species (ROS), byproducts of numerous cellular events, may serve in turn as signaling molecules to regulate cellular processes such as proliferation, differentiation, and apoptosis. However, when overproduced ROS fail to be scavenged by the antioxidant system, they may damage cellular components, giving rise to senescent, degenerative, or fatal lesions in cells. Accordingly, this review not only covers general mechanisms of ROS production under different conditions, but also focuses on various types of ROS-involved diseases, including atherosclerosis, ischemia/reperfusion injury, diabetes mellitus, neurodegenerative diseases, and cancer. In addition, potentially therapeutic agents and approaches are reviewed in a relatively comprehensive manner. However, due to the complexity of ROS and their cellular impacts, we believe that the goal to design more effective approaches or agents may require a better understanding of mechanisms of ROS production, particularly their multifaceted impacts in disease at biochemical, molecular, genetic, and epigenetic levels. Thus, it requires additional tools of omics in systems biology to achieve such a goal. Antioxid. Redox Signal. 15, 2867-2908.

Chemoprotection of ethylene glycol monoethyl ether-induced reproductive toxicity in male rats by kolaviron, isolated biflavonoid from Garcinia kola seed

The present study investigated the protective effect of kolaviron, a biflavonoid from the seed of Garcinia kola, on ethylene glycol monoethyl ether (EGEE)-induced reproductive toxicity in male rats. The protective effect of kolaviron was validated using vitamin E, a standard antioxidant. EGEE was administered at a dose of 200 mg/kg. Other groups of rats were simultaneously treated with kolaviron (100 and 200 mg/kg) and vitamin E (50 mg/kg) for 14 days. EGEE treatment resulted in significant decrease in glutathione (GSH) level, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities but markedly increased the glutathione-S-transferase (GST) and lactate dehydrogenase (LDH) activities in the testes. In the spermatozoa, administration of EGEE caused significant decrease in the activities of CAT, GPx, GST and LDH as well as in the level of GSH but significantly increased SOD activity with concomitant increase in hydrogen peroxide and malondialdehyde levels in both testes and spermatozoa. EGEE-exposed rats showed marked testicular degeneration with concomitant decrease in spermatozoa quantity and quality. Overall, EGEE causes reproductive dysfunction in rats by altering antioxidant systems in the testes and spermatozoa. Kolaviron or vitamin E exhibited protective effects against EGEE-induced male reproductive toxicity by enhancement of antioxidant status and improvement in spermatozoa quantity and quality.

Nuclear transport: a switch for the oxidative stress-signaling circuit?

Imbalances in the formation and clearance of reactive oxygen species (ROS) can lead to oxidative stress and subsequent changes that affect all aspects of physiology. To limit and repair the damage generated by ROS, cells have developed a multitude of responses. A hallmark of these responses is the activation of signaling pathways that modulate the function of downstream targets in different cellular locations. To this end, critical steps of the stress response that occur in the nucleus and cytoplasm have to be coordinated, which makes the proper communication between both compartments mandatory. Here, we discuss the interdependence of ROS-mediated signaling and the transport of macromolecules across the nuclear envelope. We highlight examples of oxidant-dependent nuclear trafficking and describe the impact of oxidative stress on the transport apparatus. Our paper concludes by proposing a cellular circuit of ROS-induced signaling, nuclear transport and repair.

Interrelationships between cadmium, zinc and antioxidants in the liver of the rat exposed orally to relatively high doses of cadmium and zinc

Zinc (Zn) reduces cadmium (Cd)-induced toxicity in the liver although it increases Cd tissue burden in some conditions; hence, the present study is designed to study the relationships between Cd, Zn and antioxidants in the liver of rats exposed to Cd. Livers of male rats which received orally relatively high doses of Cd (200 mg Cd/L as Cd chloride or Cd (200 mg/L)+Zn (500 mg Zn as Zn chloride) during five weeks, were investigated. Cd induced an accumulation of Cd and Zn in parallel to depletion in important variables (GSH, GSH/GSSG, CuZn-SOD and GPx activities) and to elevation in others (Cd/Zn and GSSG). Cd, did not affect CuZn SOD/GPx, nor Mn-SOD in the liver. Cd accumulation, Cd/Zn, CuZn SOD activity and CuZn SOD/GPx, was increased remarkably under Zn action. Zn supply ameliorated GSH level and partially reversed the decrease in GSH/GSSG, but it did not ameliorate GPx activity. Analysis showed high correlations between Cd and the majority of the variables, while Zn was positively correlated with only GSSG. We suggest from our results that Zn has indirect ameliorative effects on Cd-induced toxicity in the liver and that the increase in Cd retention is probably the key mechanism modulating, in the case of relatively high doses of Cd, the antioxidant response during exposure to Cd and Zn.

Loss of parietal cell superoxide dismutase leads to gastric oxidative stress and increased injury susceptibility in mice

Mitochondrial superoxide dismutase (SOD2) prevents accumulation of the superoxide that arises as a consequence of oxidative phosphorylation. However, SOD2 is a target of oxidative/nitrosative inactivation, and reduced SOD2 activity has been demonstrated to contribute to portal hypertensive gastropathy. We investigated the consequences of gastric parietal cell-specific SOD2 deficiency on mitochondrial function and gastric injury susceptibility. Mice expressing Cre recombinase under control of the parietal cell Atpase4b gene promoter were crossed with mice harboring loxP sequences flanking the sod2 gene (SOD2 floxed mice). Cre-positive mice and Cre-negative littermates (controls) were used in studies of SOD2 expression, parietal cell function (ATP synthesis, acid secretion, and mitochondrial enzymatic activity), increased oxidative/nitrosative stress, and gastric susceptibility to acute injury. Parietal cell SOD2 deficiency was accompanied by a 20% (P < 0.05) reduction in total gastric SOD activity and a 93% (P < 0.001) reduction in gastric SOD2 activity. In SOD2-deficient mice, mitochondrial aconitase and ATP synthase activities were impaired by 36% (P < 0.0001) and 44% (P < 0.005), respectively. Gastric tissue ATP content was reduced by 34% (P < 0.002). Basal acid secretion and peak secretagogue (histamine)-induced acid secretion were reduced by 43% (P < 0.0001) and 40% (P < 0.0005), respectively. There was a fourfold (P < 0.02) increase in gastric mucosal apoptosis and 41% (P < 0.001) greater alcohol-induced gastric damage in the parietal cell SOD2-deficient mice. Our findings indicate that loss of parietal cell SOD2 leads to mitochondrial dysfunction, resulting in perturbed energy metabolism, impaired parietal cell function, and increased gastric mucosal oxidative stress. These alterations render the gastric mucosa significantly more susceptible to acute injury.

SOD1 overexpression improves features of the oligodendrocyte precursor response in vitro

Spinal cord injury (SCI) produces a significant loss of oligodendrocytes (OL) and demyelination. The oligodendrocyte precursor cells (OPCs) response includes a group of cellular changes in OPCs that are directed to replenish OL loss from the injury. However, this adaptive response is hampered and OPCs eventually die or fail to differentiate to mature and functional OL. In this study, we wanted to evaluate if overexpression of human superoxide dismutase 1 (hSOD1) in OPCs from the SOD1 transgenic rat could improve some of the features of the OPC response in vitro. We found that hSOD1 overexpression increases the proliferation of OPCs and accelerates their differentiation to mature OL in vitro. Furthermore, hSOD1 overexpression reduces oxidative stress-mediated death in OPCs. These results suggest hSOD1 as a therapeutic target to increase OPC response success and potentially, OL replacement and remyelination after SCI.

Oxidative stress, inflamm-aging and immunosenescence

Immunosenescence is characterized by a decreased ability of the immune system to respond to foreign antigens, as well as a decreased ability to maintain tolerance to self-antigens. This results in an increased susceptibility to infection and cancer and reduced responses to vaccination [1-5]. The mechanisms underlying immunosenescence comprise a series of cellular and molecular events involving alteration of several biochemical pathways and different cellular populations, and for the most part our understanding of these molecular mechanisms is still fragmentary. In this review we will focus on the process of senescence associated with oxidative stress, in particular how protein oxidation alters the functionality of immune cells and how oxidative stress contributes to a chronic inflammatory process often referred as inflamm-aging.

Hyperlipidemic versus healthy pancreases: a proteomic analysis using an animal model

Hyperlipidemia is associated with a variety of pancreatic diseases; however, the underlying pathophysiology and molecular mechanisms remain undefined. Here, we performed a comparative proteomic analysis of pancreatic tissue obtained from hyperlipidemic rats to identify proteins that may be involved in mediating hyperlipidemia-associated pancreatic injury. Rats were fed a high-fat diet to induce hyperlipidemia. Control rats were fed a diet with normal fat content. Pancreatic tissue samples were obtained after 6 or 12 weeks and comparative proteomic analysis, using gel electrophoresis and mass spectrometry, was conducted to identify proteins, the expression of which were altered in pancreases from hyperlipidemic compared with control rat pancreases. The expression levels of 3 of 13 proteins were significantly altered in pancreatic samples from hyperlipidemic rats. Alpha-amylase and arginase II were dysregulated by more than twofold. These modulations persisted in pancreatic tissue obtained from late-stage hyperlipidemic rats. The levels of alpha-amylase and arginase II were significantly altered in pancreases obtained from rats with hyperlipidemia. These enzymes may be putative biomarkers of hyperlipidemia-mediated pancreatic injury.

Cajanus indicus leaf protein: Beneficial role in experimental organ pathophysiology. A review

The herb, Cajanus indicus L, has been and is popular for its medicinal value in India and other countries for long. The herb is mainly cultivated for the seeds which are used as pulses and are rich in proteins. People of rural India and some neighboring countries use the aqueous extract of the leaves of the herb against poor liver function and recently it has been found that the extract is not only useful against liver damage but also beneficial for renal failure and a number of other pathophysiological conditions. Intraperitoneal administration of the aqueous protein fraction of the leaves has shown hepatoprotective activity in mice. The protein fraction revealed the presence of a 43kDa protein having antioxidant and other protective properties in organ pathophysiology. The purified protein, CI-protein, scavenges free radicals generated by different free radical inducers and helps providing cytoprotection. Amino acid sequence of CI-protein has some structural similarity with plastocyanin, an electron carrier protein in photosynthesis. The protein has also been found to be active against a number of organ dysfunction inducer chemicals and drugs, like carbon tetrachloride, thioacetamide and acetaminophen. Signal transduction studies suggest that CI-protein exerts its protective action by free radical scavenging and antioxidative properties; it activates NF-κB and Akt without any involvement of ERK1/ERK2 and STAT-3 in acetaminophen induced hepatic pathophysiology. Besides, it reduces both drug and toxin induced cytotoxicity by decreasing the formation and/or scavenging of free radicals involving cytochrome P450, taking part in detoxification of xenobiotics.

Phytochemical Analysis and Antioxidant Property of Leaf Extracts of Vitex doniana and Mucuna pruriens

Oxidative stress and impaired antioxidant system have been implicated in the pathophysiology of diverse disease states. The phytochemical screening and antioxidant property of fresh leaves of Vitex doniana and Mucuna pruriens, used in the management and treatment of various diseases, were studied. The extracts (ethanol and distilled water) were screened for the presence of phytochemicals, and their inhibition of 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical was used to evaluate their free radical scavenging activity. Liver levels of malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) in carbon tetrachloride- (CCl₄) treated albino rats were also used to assess the antioxidant activity of the extracts. The animals were treated with 250 mg/kg body weight of the extracts for six consecutive days before a single dose (2.5 mL/kg body weight) of CCl₄. Vitamin C was used as the standard antioxidant. Phytochemical screening revealed the presence of saponins, tannins, anthraquinones, terpenoids, and flavonoids in all the extracts, while alkaloids were detected in extracts of Vitex doniana only, and cardiac glycosides occurred in extracts of Mucuna pruriens only. All the extracts inhibited DPPH radical in a concentration-dependent manner, water extract of Vitex doniana producing highest inhibition which was not significantly different (P > .05) from vitamin C. The extracts produced a significant decrease (P < .05) in liver MDA, while the levels of SOD and CAT significantly increased (P < .05) relative to the positive control. These results are an indication of antioxidant potential of the extracts and may be responsible for some of the therapeutic uses of these plants.

Cortico-striatal oxidative status, dopamine turnover and relation with stereotypy in the deer mouse

The deer mouse presents with spontaneous stereotypic movements that resemble the repetitive behaviours of obsessive-compulsive disorder (OCD), and demonstrates a selective response to serotonin reuptake inhibitors. OCD has been linked to altered redox status and since increased dopamine signalling can promote stereotypies as well as oxidative stress, we investigated whether the severity of deer mouse stereotypy may be associated with altered dopamine turnover and cortico-striatal redox status. Deer mice were separated into high (HSB), low (LSB) and non-stereotypy (NS) groups. Frontal cortical and striatal dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), as well as superoxide dismutase (SOD) activity, reduced (GSH) and oxidised (GSSG) glutathione and glutathione redox index, were analysed as markers for regional dopamine turnover and oxidative stress, respectively. Dopamine and its metabolites and SOD activity did not differ across the stereotypy groups. Significantly reduced GSH and GSSG and increased glutathione redox index were only observed in the frontal cortex of HSB animals. Frontal cortical GSH and GSSG were inversely correlated while glutathione redox index was positively correlated with stereotypy. Deer mouse stereotypy is thus characterised by a deficient glutathione system in the frontal cortex but not striatum, and provides a therapeutic rationale for using glutathione-active antioxidants in OCD. The evidence for a primary frontal lesion has importance for future OCD research.

Relationship between plasma carotenoids, fruit and vegetable intake, and plasma extracellular superoxide dismutase activity in women: different in health and disease?

Abstract Exogenous antioxidants may influence endogenous antioxidant enzyme activity. We observed in healthy women (n = 95) that higher plasma α-carotene, β-carotene, β-cryptoxanthin, sum of plasma carotenoids, and fruit and vegetable intake were associated with lower plasma extracellular-superoxide dismutase activity. In women with a history of cardiovascular disease, diabetes, or cancer (n = 62), we observed no associations. Our observation that plasma extracellular-superoxide dismutase activity was inversely associated with plasma carotenoids and fruit and vegetable intake in healthy women, but not in women with a history of cardiovascular disease, diabetes, or cancer, suggests that the associations between exogenous and endogenous antioxidants may differ in health and disease.

Effect of n-3 fatty acids and statins on oxidative stress in statin-treated hypercholestorelemic and normocholesterolemic women

INTRODUCTION

Although the combination of statins with n-3 fatty acids seems to be beneficial under the lipid profile aspect, there is little information about the interaction of these two compounds on oxidative stress.

OBJECTIVE

Evaluate the interaction between statins and n-3 fatty acids on oxidative stress in women, using a 2² factorial design.

METHODS

Forty-three women participated in this crossover design. They were separated into two groups in which 20 were under statin treatment for more than 6 months, and 23 were normolipidemic. Within each group, half of the patients received capsules containing 2.4 g/day of a mixture of EPA and DHA for 6 weeks, while the other half received a mixture of soya and corn oil. After a period of 90 days of washout, the groups were switched, and received the supplementation for 6 weeks more.

RESULTS

Statins reduced serum LDL and increased SOD expression. n-3 fatty acids increased the plasma malondialdehyde and SOD activity but reduced catalase expression (p<0.05). The interaction involving statins and n-3 fatty acids was nearly significant to the serum triacylglycerol reduction (p=0.054).

CONCLUSION

Combining statins and n-3 fatty acids is an excellent strategy to reduce plasma cholesterol and triacylglycerol concentration in women. However, n-3 fatty acids increased the oxidative stress and the pleiotropic effect of statins seemed to be not enough to counterbalance this result. Our data also suggested that the mechanism by which n-3 fatty acids interfere in oxidative stress can be associated with antioxidant enzymes expression and activity.

Influence of dietary vitamin E and zinc on performance, oxidative stability and some blood measures of broiler chickens reared under heat stress (35 °C)

This study was conducted to determine the effects of vitamin E (αTA; dL-α-Tocopheryl acetate) and zinc (Zn; ZnCl2) on performance, oxidative stability and some blood measures of broiler chickens under normal and hot temperatures. One hundred sixty 10-day-old male chicks were assigned to four groups in four replicates. The birds received two diets, control and enriched with two levels of vitamin E and Zn (100 and 50 mg/kg of diet, respectively) under two ambient temperatures (22 °C and 35 °C). Although the diets enriched with the antioxidant vitamin and element compared with un-enriched diets resulted in the better performance of the birds, significant differences were related to temperature conditions, as the lowest feed conversion ratio (FCR) and the highest body weight (BW) were observed in the group fed the enriched diet under normal temperature. The serum malondialdehyde (MDA), cholesterol (C), triglycerides (TG), glucose (G), total protein (TP), and hematocrit and heterophil: lymphocyte ratio levels were significantly lower in birds reared under 22 °C compared with the group under 35 °C but the hematocrit was not significantly lower in groups fed enriched diets and exposed to normal conditions (P>0.05). It was concluded that a combination of 100 mg of vitamin E and 50 mg of Zn provides the better performance and the least blood C and TG levels accompanying the better oxidative stability in male broilers under normal temperature (22 °C) and that this combination can be considered as a protective strategy in broiler diets for reducing the negative effects of heat stress.

Reactive oxygen species and vascular biology: implications in human hypertension

Increased vascular production of reactive oxygen species (ROS; termed oxidative stress) has been implicated in various chronic diseases, including hypertension. Oxidative stress is both a cause and a consequence of hypertension. Although oxidative injury may not be the sole etiology, it amplifies blood pressure elevation in the presence of other pro-hypertensive factors. Oxidative stress is a multisystem phenomenon in hypertension and involves the heart, kidneys, nervous system, vessels and possibly the immune system. Compelling experimental and clinical evidence indicates the importance of the vasculature in the pathophysiology of hypertension and as such much emphasis has been placed on the (patho)biology of ROS in the vascular system. A major source for cardiovascular, renal and neural ROS is a family of non-phagocytic nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Nox), including the prototypic Nox2 homolog-based NADPH oxidase, as well as other Noxes, such as Nox1 and Nox4. Nox-derived ROS is important in regulating endothelial function and vascular tone. Oxidative stress is implicated in endothelial dysfunction, inflammation, hypertrophy, apoptosis, migration, fibrosis, angiogenesis and rarefaction, important processes involved in vascular remodeling in hypertension. Despite a plethora of data implicating oxidative stress as a causative factor in experimental hypertension, findings in human hypertension are less conclusive. This review highlights the importance of ROS in vascular biology and focuses on the potential role of oxidative stress in human hypertension.

Oxidation and age-related macular degeneration: insights from molecular biology

Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. It is a multifactorial disease, and current therapy predominantly limits damage only when it has already occurred. The macula is a source of high metabolic activity, and is therefore exposed to correspondingly high levels of reactive oxygen species (ROS). With age, the balance between production of ROS and local antioxidant levels is shifted, and damage ensues. Systemic ROS and antioxidant levels in AMD reflect these local processes. Genetic studies investigating mutations in antioxidant genes in AMD are inconclusive and further studies are indicated, especially to determine the role of mitochondria. Oral antioxidant supplements could be beneficial, and diet modification may help. Future treatments might either increase antioxidant capacity or reduce the production of ROS, using methods such as genetic manipulation. This article reviews the role of oxidative stress in AMD and the potential therapies that might have a role in preventing the blindness resulting from this disease.

Chromium III histidinate exposure modulates gene expression in HaCaT human keratinocytes exposed to oxidative stress

While the toxicity of hexavalent chromium is well established, trivalent chromium is an essential nutrient involved in insulin and glucose homeostasis. To study the antioxidant effects of Cr(III)His, cDNA arrays were used to investigate the modulation of gene expression by trivalent chromium histidinate (Cr(III)His) in HaCaT human keratinocytes submitted to hydrogen peroxide (H2O2). Array was composed by a set of 81 expressed sequences tags (ESTs) essentially represented by antioxidant and DNA repair genes. HaCaT were preincubated for 24 h with 50 microM Cr(III)His and were treated with 50 muM H2O2. Total RNAs were isolated immediately or 6 h after the stress. In Cr(III)His preincubated cells, transcripts related to antioxidant family were upregulated (glutathione synthetase, heme oxygenase 2, peroxiredoxin 4). In Cr(III)His preincubated cells and exposed to H2O2, increased expressions of polymerase delta 2 and antioxidant transcripts were observed. Biochemical methods performed in parallel to measure oxidative stress in cells showed that Cr(III)His supplementation before H2O2 stress protected HaCaT from thiol groups decrease and thiobarbituric acid reactive substances increase. In summary, these results give evidence of antioxidant gene expression and antioxidant protection in HaCaT preincubated with Cr(III)His and help to explain the lack of toxicity reported for Cr(III)His.

KRIT1 regulates the homeostasis of intracellular reactive oxygen species

KRIT1 is a gene responsible for Cerebral Cavernous Malformations (CCM), a major cerebrovascular disease characterized by abnormally enlarged and leaky capillaries that predispose to seizures, focal neurological deficits, and fatal intracerebral hemorrhage. Comprehensive analysis of the KRIT1 gene in CCM patients has suggested that KRIT1 functions need to be severely impaired for pathogenesis. However, the molecular and cellular functions of KRIT1 as well as CCM pathogenesis mechanisms are still research challenges. We found that KRIT1 plays an important role in molecular mechanisms involved in the maintenance of the intracellular Reactive Oxygen Species (ROS) homeostasis to prevent oxidative cellular damage. In particular, we demonstrate that KRIT1 loss/down-regulation is associated with a significant increase in intracellular ROS levels. Conversely, ROS levels in KRIT1^−/− cells are significantly and dose-dependently reduced after restoration of KRIT1 expression. Moreover, we show that the modulation of intracellular ROS levels by KRIT1 loss/restoration is strictly correlated with the modulation of the expression of the antioxidant protein SOD2 as well as of the transcriptional factor FoxO1, a master regulator of cell responses to oxidative stress and a modulator of SOD2 levels. Furthermore, we show that the KRIT1-dependent maintenance of low ROS levels facilitates the downregulation of cyclin D1 expression required for cell transition from proliferative growth to quiescence. Finally, we demonstrate that the enhanced ROS levels in KRIT1^−/− cells are associated with an increased cell susceptibility to oxidative DNA damage and a marked induction of the DNA damage sensor and repair gene Gadd45α, as well as with a decline of mitochondrial energy metabolism. Taken together, our results point to a new model where KRIT1 limits the accumulation of intracellular oxidants and prevents oxidative stress-mediated cellular dysfunction and DNA damage by enhancing the cell capacity to scavenge intracellular ROS through an antioxidant pathway involving FoxO1 and SOD2, thus providing novel and useful insights into the understanding of KRIT1 molecular and cellular functions.

Neutrophil gelatinase-associated lipocalin induces the expression of heme oxygenase-1 and superoxide dismutase 1, 2

Lipocalin-2 (Lcn2, NGAL) is a member of the lipocalin super family with diverse function such as the induction of apoptosis, the suppression of bacterial growth, and modulation of inflammatory response. Much interest has recently been focused on the physiological/pathological role of the lipocalin-2 that is considered to be a novel protective factor against oxidative stress. However, its precise biological roles in this protection are not fully understood. In this report we intended to test the effect of lipocalin-2 on the expression of heme oxygenase ((1, 2)) and superoxide dismutase ((1, 2)) which are two strong antioxidants. NGAL was cloned to pcDNA3.1 plasmid by using genetic engineering method. The recombinant vector was transfected to CHO and HEK293T to establish stable cell expressing NGAL and the expression of HO-1, 2 and SOD(1, 2) were compared with appropriate controls by RT-PCR and western blot. On the other hand, expression of NGAL was suppressed by siRNA transfection in order to study the effect of lipocalin-2 on mentioned genes/proteins. The results showed that the expression of HO-1 and SOD(1, 2) enzymes were higher in cells expressing recombinant lipocalin-2 compared with the control cells. Although the expression of HO-1 was lower in NGAL silencing cells, the expression of SOD(1) and SOD(2) were higher. Our data suggest that NGAL is a potent inducer of HO-1 and somewhat SOD(1) and SOD(2) and it appears that part of antioxidant property of NGAL could be attributed to the induction of HO-1 and SOD(1, 2).

Free radicals, antioxidants and functional foods: Impact on human health

In recent years, there has been a great deal of attention toward the field of free radical chemistry. Free radicals reactive oxygen species and reactive nitrogen species are generated by our body by various endogenous systems, exposure to different physiochemical conditions or pathological states. A balance between free radicals and antioxidants is necessary for proper physiological function. If free radicals overwhelm the body's ability to regulate them, a condition known as oxidative stress ensues. Free radicals thus adversely alter lipids, proteins, and DNA and trigger a number of human diseases. Hence application of external source of antioxidants can assist in coping this oxidative stress. Synthetic antioxidants such as butylated hydroxytoluene and butylated hydroxyanisole have recently been reported to be dangerous for human health. Thus, the search for effective, nontoxic natural compounds with antioxidative activity has been intensified in recent years. The present review provides a brief overview on oxidative stress mediated cellular damages and role of dietary antioxidants as functional foods in the management of human diseases.

Oxidative stress mediates nephropathy in type Ia glycogen storage disease

Glycogen storage disease type Ia (GSD-Ia) patients, deficient in glucose-6-phosphatase-alpha, manifest disturbed glucose homeostasis with long-term renal disease. We have previously shown that renal fibrosis in GSD-Ia is mediated by the angiotensin/transforming growth factor-beta1 (TGF-beta1) pathway, which also elicits renal damage through oxidative stress. In this study, we further elucidate the mechanism of renal disease by showing that renal expression of Nox-2, p22(phox), and p47(phox), components of NADPH oxidase, are upregulated in GSD-Ia mice compared with controls. Akt/protein kinase B, a downstream mediator of angiotensin II and TGF-beta1, is also activated, leading to phosphorylation and inactivation of the Forkhead box O family of transcription factors. This in turn triggers downregulation of superoxide dismutase and catalase (CAT) activities that have essential roles in oxidative detoxification in mammals. Renal oxidative stress in GSD-Ia mice is shown by increased oxidation of dihydroethidium and by oxidative damage of DNA. Importantly, renal dysfunction, reflected by elevated serum levels of blood urea nitrogen, reduced renal CAT activity, and increased renal fibrosis, is improved in GSD-Ia mice treated with the antioxidant drug tempol. These data provide the first evidence that oxidative stress is one mechanism that underlies GSD-Ia nephropathy.

Boric acid: a potential chemoprotective agent against aflatoxin b(1) toxicity in human blood

Aflatoxin B(1) is the most potent pulmonary and hepatic carcinogen. Since the eradication of Aflatoxin B(1) contamination in agricultural products has been difficult, the use of natural or synthetic free radical scavengers could be a potential chemopreventive strategy. Boric acid is the major component of industry and its antioxidant role has recently been reported. The present study assessed, for the first time, the effectiveness of boric acid following exposure to Aflatoxin B(1) on human whole blood cultures. The biochemical characterizations of glutathione and some enzymes have been carried out in erythrocytes. Alterations in malondialdehyde level were determined as an index of oxidative stress. The sister-chromatid exchange and micronucleus tests were performed to assess DNA damages in lymphocytes. Aflatoxin B(1) treatment significantly reduced the activities of antioxidants by increasing malondialdehyde level (30.53 and 51.43%) of blood, whereas, the boric acid led to an increased resistance of DNA to oxidative damage induced by Aflatoxin B(1) in comparison with control values (P < 0.05). In conclusion, the support of boric acid was especially useful in Aflatoxin-toxicated blood. Thus the risk on tissue targeting of Aflatoxin B(1) could be reduced ensuring early recovery from its toxicity.

Energy metabolism in hypoxia: reinterpreting some features of muscle physiology on molecular grounds

An holistic approach for interpreting classical data on the adaptation of the animal and, particularly, of the human body to hypoxic stress was promoted by the discovery of HIF-1, the "master regulator" of cell hypoxic signaling. Mitochondrial production of ROS stabilizes the O(2)-regulated HIF-1α subunit of the HIF-1 dimer promoting transaction functions in a large number of potential target genes, activating transcription of sequences into RNA and, eventually, protein production. The aim of the present preliminary study is to assess whether adaptive changes in oxygen sensing and metabolic signaling, particularly in the control of energy turnover known to occur in cultured cells exposed to hypoxia, are detectable also in the muscles of animals and man. For the present analysis, data obtained from the proteome of the rat gastrocnemius and of the vastus lateralis muscle of humans together with functional measurements were compared with homologous data from hypoxic cultured cells. In particular, the following variables were assessed: (1) the role of stress response proteins in the maintenance of ROS homeostasis, (2) the activity of the PDK1 gene on the shunting of pyruvate away from the TCA cycle in rodents and in humans, (3) the COX-4/COX-2 ratio in hypoxic rodents, (4) the overall efficiency of oxidative phosphorylation in humans during exercise in hypoxia, (5) some features of muscle mitochondrial autophagy in humans undergoing subchronic and chronic altitude exposure. Despite the limited number of observations and the differences in the experimental approach, some initial interesting results were obtained encouraging to pursue this innovative effort.

Profiling of superoxide dismutase isoenzymes in compartments of the developing bovine antral follicles

The antral follicle constitutes a complex and regulated ovarian microenvironment that influences oocyte quality. Oxidative stress is a cellular state that may play a role during folliculogenesis and oogenesis, although direct supporting evidence is currently lacking. We thus evaluated the expression of the three isoforms (SOD1, SOD2, and SOD3) of the enzymatic antioxidant superoxide dismutase in all the cellular (granulosa cells, cumulus cells, and oocytes) and extracellular (follicular fluid) compartments of the follicle. Comparisons were made in bovine ovaries across progressive stages of antral follicular development. Follicular fluid possessed increased amounts of SOD1, SOD2, and SOD3 in small antral follicles when compared with large antral follicles; concomitantly, total SOD activity was highest in follicular fluids from smaller diameter follicles. SOD1, SOD2, and SOD3 proteins were expressed in granulosa cells without any fluctuations in follicle sizes. All three SOD isoforms were present, but were distributed differently in oocytes from small, medium, or large antral follicles. Cumulus cells expressed high levels of SOD3, some SOD2, but no detectable SOD1. Our studies provide a temporal and spatial expression profile of the three SOD isoforms in the different compartments of the developing bovine antral follicles. These results lay the ground for future investigations into the potential regulation and roles of antioxidants during folliculogenesis and oogenesis.

Raphanus sativus extract prevents and ameliorates zearalenone-induced peroxidative hepatic damage in Balb/c mice

Objectives

Raphanus sativus (radish) is a species of crucifer, which includes widely consumed vegetables, distributed in Asia, Africa and Europe. It is a rich source of bioactive molecules including anthocyanins, glucosinolates, isothiocyanates and other flavonoids, and miscellaneous phenolic substances. We have evaluated the hepatoprotection of R. sativus extract against zearalenone, an estrogenic mycotoxin initiating hepatotoxicity in male Balb/c mice.

Methods

Animals were divided into seven treatment groups and treated orally each day for twenty eight days as follows: a control, an olive oil group, group I, group II, and group III treated with radish extract alone (5, 10 and 15 mg/kg, respectively), group IV treated with zearalenone (40 mg/kg), and group V treated with zearalenone plus the lowest dose of radish extract.

Key findings

Administration of zearalenone alone resulted in significant decreases in the levels of alkaline phosphatase, lactate dehydrogenase, alanine and aspartate aminotransferases in the liver, suggesting hepatic damage. Moreover, a marked increase in the level of lipid peroxide and concomitant decrease of glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, glutathione-S-transferase, RNA and DNA concentrations were also observed in the liver tissue of zearalenone-treated mice. Co-treatment with R. sativus extract plus zearalenone succeeded in reversing the condition back to normal levels for all studied parameters.

Conclusions

By itself R. sativus extract did not show any toxic effects and could be considered as a potent hepatoprotectant.

Preventive effects of a cocoa-enriched diet on gingival oxidative stress in experimental periodontitis

BACKGROUND

Oxidative stress affects the progression of periodontitis. Cocoa is a rich source of flavonoids with antioxidant properties, which could suppress gingival oxidative stress in periodontal lesions. The purpose of the present study was to investigate the effects of a cocoa-enriched diet on gingival oxidative stress in a rat-periodontitis model.

METHODS

In this 4-week study, rats were divided into three groups (n = 8/group): a control group (fed a regular diet) and two periodontitis groups (fed a regular diet or cocoa-enriched diet [10% of food intake]). Periodontitis was induced by ligature placement around the mandibular first molars. Serum levels for reactive oxygen metabolites were measured at baseline and 2 and 4 weeks. At 4 weeks, the levels of 8-hydroxydeoxyguanosine and reduced/oxidized glutathione ratio were determined to evaluate gingival oxidative damage and antioxidant status, respectively.

RESULTS

Rats with experimental periodontitis that were fed a regular diet showed an increase in the level of serum reactive oxygen metabolites in a time-dependent manner. These rats also had an increased 8-hydroxydeoxyguanosine level and decreased reduced/oxidized glutathione ratio in the gingival tissue, inducing alveolar bone loss and polymorphonuclear leukocyte infiltration. Although experimental periodontitis was induced in the rats fed a cocoa-enriched diet, they did not show impairments in serum reactive oxygen metabolite level and gingival levels for 8-hydroxydeoxyguanosine and reduced/oxidized glutathione ratio. Alveolar bone loss and polymorphonuclear leukocyte infiltration after ligature placement were also inhibited by cocoa intake.

CONCLUSION

Consuming a cocoa-enriched diet could diminish periodontitis-induced oxidative stress, which, in turn, might suppress the progression of periodontitis.

A novel manganese complex effective as superoxide anion scavenger and therapeutic agent against cell and tissue oxidative injury

Two cyclic polyamine-polycarboxylate ligands, 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (H(2)L3) and 4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (H(2)L4), and two noncyclic scaffolds, N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (H(3)L1) and ethylene-bisglycol-tetracetic acid (H(4)L2), form stable complexes with Mn(II) in aqueous solutions. Cyclic voltammograms show that the complexes with the most hydrophobic ligands, [MnL2](2-) and [MnL4], are oxidized at higher potential than [MnL1](-) and [MnL3]. The pharmacological properties of these molecules were evaluated as superoxide ion scavengers and anti-inflammatory compounds. Among the four complexes, [MnL4] was the most bioactive, being effective in the nanomolar/micromolar range. It abates the levels of key markers of oxidative injury on cultured cells and ameliorates the outcome parameters in animal models of acute and chronic inflammation. [MnL4] toxicity was very low on both cell cultures in vitro and mice in vivo. Hence, we propose [MnL4] as a novel stable oxygen radical scavenging molecule, active at low doses and with a low toxicity.

The impact of human superoxide dismutase 1 expression in a mouse model on the embryotoxicity of hydroxyurea

BACKGROUND

Oxidative stress is hypothesized to mediate embryotoxicity during organogenesis, yet the reactive oxygen species involved are not defined. The superoxide oxygen radical is converted to hydrogen peroxide, a less reactive species, by superoxide dismutases (SODs). If superoxide is important in mediating embryotoxicity, increased SOD expression should protect embryos against insult. Exposure to hydroxyurea during organogenesis causes brain defects, cleft palate, tail anomalies, and limb defects; administration of D-mannitol, a free radical scavenger, ameliorates hydroxyurea embryotoxicity, suggesting that oxidative stress is important. To elucidate the role of superoxide in mediating hydroxyurea embryotoxicity, we assessed the impact of human SOD1 expression in a murine model.

METHODS

hSOD1 hemizygous male mice, carrying the human SOD1 gene, were mated to wild-type or hSOD1 hemizygous females. Dams were treated on gestation day (GD) 9 with saline (control) or 400 (low) or 600 (high) mg/kg hydroxyurea (n = 8-13/group). Mice were euthanized on GD 18 and developmental toxicity was assessed.

RESULTS

Exposure to hydroxyurea caused a dose-dependent increase in fetal deaths that was not affected by hSOD1 expression; hydroxyurea decreased fetal weights in litters from wild-type but not hemizygous dams. Hydroxyurea increased the incidence of external and skeletal malformations; fetuses from hemizygous dams treated with high-dose hydroxyurea had fewer malformations compared to wild-type dams. There was no correlation between embryonic phenotype and genotype or SOD activity.

CONCLUSION

Maternal hSOD1 expression protected fetuses against malformations induced by hydroxyurea, providing evidence that superoxide plays a role in mediating the response of organogenesis stage embryos to this teratogen.

Telomeric DNA induces p53-dependent reactive oxygen species and protects against oxidative damage

BACKGROUND

Reactive oxygen species (ROS) are generated by cellular metabolism as well as by exogenous agents. While ROS can promote cellular senescence, they can also act as signaling molecules for processes that do not lead to senescence. Telomere homolog oligonucleotides (T-oligos) induce adaptive DNA damage responses including increased DNA repair capacity and these effects are mediated, at least in part, through p53.

OBJECTIVE

Studies were undertaken to determine whether such p53-mediated protective responses include enhanced antioxidant defenses.

METHODS

Normal human fibroblasts as well as R2F fibroblasts expressing wild type or dominant negative p53 were treated with an 11-base T-oligo, a complementary control oligo or diluents alone and then examined by western blot analysis, immunofluorescence microscopy and various biochemical assays.

RESULTS

We now report that T-oligo increases the level of the antioxidant enzymes superoxide dismutase 1 and 2 and protects cells from oxidative damage; and that telomere-based gammaH2AX (DNA damage) foci that form in response to T-oligos contain phosphorylated ATM and Chk2, proteins known to activate p53 and to mediate cell cycle arrest in response to oxidative stress. Further, T-oligo increases cellular ROS levels via a p53-dependent pathway, and these increases are abrogated by the NAD(P)H oxidase inhibitor diphenyliodonium chloride.

CONCLUSION

These results suggest the existence of innate telomere-based protective responses that act to reduce oxidative damage to cells. T-oligo treatment induces the same responses and offers a new model for studying intracellular ROS signaling and the relationships between DNA damage, ROS, oxidative stress, and cellular defense mechanisms.