1. Oxidative stress, potentially, is experienced by all aerobic life when antioxidant defenses are overcome by prooxidant forces, and is the basis of many physiological abberations. 2. Environmental contaminants may enhance oxidative stress in aquatic organisms, e.g. highly elevated rates of ideopathic lesions and neoplasia among fish inhabiting polluted environments is increasingly related to oxidative stress associated with environmental pollution. <em>3</em>. Metabolism of redox cycling xenobiotics in aquatic organisms is very similar to that of mammals suggesting similarities in the health consequences of exposure to such compounds. 4. The expression of specific lesions known to arise specifically from oxidative stress, e.g. lipid peroxidation, oxidized bases in DNA and accumulation of lipofuscin pigments are present in many aquatic animals exposed to contaminants. 5. Aquatic organisms contain the major antioxidant enzymes <em>SOD</em>, catalase and glutathione peroxidase, albeit there are marked quantitative differences among the various species reported.

Fibrosis of the glomerulus and the tubulointerstitium occurs in patients with hypertension. Studies have shown that renal oxidative stress appears in hypertensive kidney disease. The potential role of oxidative stress in renal fibrogenesis remains to be elucidated. Herein, we tested the hypothesis that oxidative stress contributes to the development of renal fibrosis during hypertension.Sprague-Dawley rats received angiotensin II (AngII; 9 microg/h s.c.) for 4 weeks with/without co-treatment of antioxidants, apocynin and tempol (120 mg/kg/day each, p.o.). Untreated rats served as controls. Appearance of renal oxidative stress and its effect on the expression of transforming growth factor (TGF)-beta(1), population of myofibroblasts, collagen synthesis/degradation and fibrosis in kidneys were examined. Chronic AngII infusion elevated systemic blood pressure (228 +/- 6 mm Hg), which was accompanied with extensive renal fibrosis and oxidative stress represented as upregulated NADPH oxidase and suppressed superoxide dismutase (<em>SOD</em>). Co-treatment with antioxidants led to: (1) markedly decreased renal NADPH oxidase; (2) significantly attenuated gene expression of TGF-beta(1), type I collagen, and tissue inhibitors of matrix metalloproteinase (TIMP)-I/-II in the kidney; (<em>3</em>) largely reduced population of myofibroblasts in both the cortex and medulla; (4) significantly reduced renal collagen volume, and (5) partially suppressed blood pressure (190 +/- 8 mm Hg). Thus, prolonged AngII administration promotes renal oxidative stress, which is associated with hypertensive renal disease. AngII induces renal oxidative stress by increasing NADPH oxidase and reducing <em>SOD</em> in the kidney, which, in turn, upregulates collagen synthesis, while suppressing collagen degradation, thereby promoting the development of fibrosis in kidneys of hypertensive rats.

Superoxide production by NADPH oxidases plays an important role in the development and progression of cardiovascular disease (CVD). However, measurement of superoxide (O(2)(-)), a marker of oxidative stress, remains a challenging task in clinical and translational studies. In this study we analyzed O(2)(-) production in cultured human lymphoblast cell lines by three different methods: (a) superoxide dismutase (<em>SOD</em>)-inhibitable cytochrome C reduction, (b) spin trapping of superoxide with 5-(ethoxycarbonyl)-5-methyl-1-pyrroline N-oxide (EMPO) and 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO), and (c) using electron spin resonance (ESR) with the cell-permeable spin probe 1-hydroxy-<em>3</em>-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (CMH). Lymphocytes were isolated and immortalized by an Epstein-Barr Virus (EBV)-transformation procedure. Superoxide was measured in cultured lymphoblast cell lines at baseline and upon stimulation with phorbol 12-myristate 1<em>3</em>-acetate (PMA). Cytochrome C and the spin traps EMPO and DEPMPO detected two to five times less superoxide compared to CMH. Thus, CMH provided the most quantitative measurement of superoxide generation in human lymphoblast cell lines. Superoxide detection with CMH was linear dependent on cell concentration and was inhibited by <em>SOD</em> but not by catalase. Both cell-permeable polyethylene glycol (PEG)-<em>SOD</em> and extracellular Cu,Zn-<em>SOD</em> inhibited O(2)(-) detection by 90% in PMA-stimulated cells, suggesting a predominantly extracellular O(2)(-) generation in human lymphoblasts. Our study describes a new technique for O(2)(-) measurement in cultured human lymphoblasts using ESR and CMH. A highly sensitive in vitro measurement of O(2)(-) in human cell lines would allow investigators to study genotype/phenotype interactions in translational studies.

1. Structurally distinct superoxide dismutase (<em>SOD</em>) mimetics were examined for their ability to protect nitric oxide (NO) from destruction by oxidant stress in rabbit aorta. 2. These were the spin traps, PTIYO (4-phenyl-2,2,5,5-tetramethyl imidazolin-1-yloxy-5-oxide), tempol (4-hydroxy 2,2,6,6,-tetramethylpiperidine-1-oxyl) and tiron (4,5-dihydroxy-1,<em>3</em>-benzene-disulphonic acid), the metal salts, CuSO4 and MnCl2, and the metal-based agents CuDIPS (Cu (II)-[diisopropylsalicylate]2) and MnTMPyP (Mn (III) tetrakis [1-methyl-4-pyridyl]porphyrin). <em>3</em>. Oxidant stress was generated in isolated aortic rings by inactivating endogenous Cu/Zn <em>SOD</em> with diethyldithiocarbamate (DETCA; 60 min) either alone at <em>3</em> mM or at 0.<em>3</em> mM in combination with superoxide generation using xanthine oxidase (XO; 4.8 mu ml(-1)) and hypoxanthine (HX; 0.1 mM). 4. Acetylcholine (ACh)-induced relaxation was inhibited by DETCA (<em>3</em> mM, 60 min) and was not restored by exogenous <em>SOD</em> (250 u ml(-1)), suggesting the oxidant stress was intracellular. MnTMPyP (600 microM and 1 mM) and MnCl2 (100 microM) were the only agents to reverse the blockade of ACh-induced relaxation. 5. Addition of XO/HX to DETCA (0.<em>3</em> mM)-treated tissues powerfully impaired ACh-induced relaxation and exogenous <em>SOD</em> (250 u ml(-1)) fully reversed the blockade, suggesting the oxidant stress was extracellular. CuDIPS (0.1-<em>3</em> microM), CuSO4 (0.<em>3</em>-<em>3</em> microM), MnCl2 (1-100 microM) and MnTMPyP (100-600 microM) also reversed blockade powerfully, tempol (<em>3</em>0 microM-1 mM) and tiron (0.<em>3</em>-10 mM) reversed blockade weakly and PTIYO (10-<em>3</em>00 microM) enhanced the blockade. 6. Thus, MnTMPyP was the only <em>SOD</em> mimetic to restore NO-dependent relaxation in conditions of both extracellular and intracellular oxidant stress. This agent may, therefore, provide a lead in the development of <em>SOD</em> mimetics for the treatment of pathologies associated with oxidant stress.

The present study analyses the influence of hypertension and endothelium on the effect induced by hydrogen peroxide (H2O2) on basal tone in aortic segments from normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) of 6-month-old, as well as the possible mechanisms involved. Single (1 mM) or cumulative (100 nM-10 mM) concentrations of H2O2 produced a transient contraction or a concentration-dependent increase of basal tone, respectively, in segments from WKY and SHR. In both cases, the contractions were higher in intact segments from hypertensive than from normotensive rats, and increased by endothelium removal in both strains. Catalase (1000 u ml(-1), a H2O2 scavenger) abolished the contraction elicited by 1 mM H2O2 in both strains. Superoxide dismutase (<em>SOD</em>, 150 u ml(-1)) and dimethylsulphoxide (DMSO, 7 mM), scavengers of superoxide anions and hydroxyl radicals, respectively, did not alter H2O2-induced contractions in intact segments from both strains. However, L-NG-nitroarginine methyl ester (L-NAME, 100 microM, a nitric oxide synthase inhibitor) increased the response to H2O2 in normotensive rats, although the increase was less than that produced by endothelium removal. Incubation of segments with 1 mM H2O2 for 15 min and subsequent washout reduced the contractile responses induced by 75 mM KCl in intact segments from SHR and in endothelium-denuded segments from both strains; this effect being prevented by catalase (1000 u ml(-1)). Indomethacin (10 microM, a cyclo-oxygenase inhibitor) and SQ 29,548 (10 microM, a prostaglandin H2/thromboxane A2 receptor antagonist) practically abolished the contractions elicited by H2O2 in normotensive and hypertensive rats. We conclude that: (1) the oxidant stress induced by H2O2 produces contractions mediated by generation of a product of the cyclo-oxygenase pathway, prostaglandin H2 or more probably thromboxane A2, in normotensive and hypertensive rats; (2) oxygen-derived free radicals are not involved in the effect of H2O2; (<em>3</em>) in normotensive rats, endothelium protects against H2O2-mediated injury to contractile machinery, determined by the impairment of KCl-induced contractions; and (4) endothelial nitric oxide has a protective role on the contractile effect induced by H2O2, that is lost in hypertension.

1. The role of endothelium-derived relaxing factor (EDRF) in the action of vasodilator (acetylcholine, histamine, nitroprusside) and vasoconstrictor (noradrenaline, vasopressin) drugs on vascular resistance in the isolated perfused kidney and mesentery of the rat was studied. 2. Acetylcholine (EC50 = 0.18 +/- 0.05 nmol and <em>3</em>.1 +/- 0.06 nmol, n = 8) and histamine (EC50 = <em>3</em>1.2 +/- 4.9 nmol and 46.2 +/- <em>3</em>.9 nmol, n = 8) produced dose-related vasodilatation in noradrenaline-preconstricted (i.e. 'high tone') rat renal and mesenteric blood vessels. The response to both vasodilators (but not nitroprusside) was abolished by infusion of CHAPS (4.7 mg ml-1, <em>3</em>0 s). By use of an immunocytochemical staining procedure CHAPS was demonstrated to remove vascular endothelial cells lining intrarenal blood vessels. <em>3</em>. Gossypol (<em>3</em> microM), metyrapone (10 microM) and nordihydroguaiaretic acid, (NDGA, <em>3</em>0 microM), presumed inhibitors of EDRF biosynthesis, reduced or abolished the response to acetylcholine and histamine in perfused kidney and mesentery of the rat without affecting vasodilatation due to nitroprusside. Mepacrine (10 microM) similarly abolished the response to acetylcholine and histamine but in addition, reduced the response to nitroprusside in both preparations. 4. Methylene blue (100 microM), a presumed antagonist of the effect of EDRF, abolished vasodilatation due to acetylcholine and histamine and reduced the response to nitroprusside in perfused rat kidney and mesentery. Superoxide dismutase, <em>SOD</em> (15 u ml-1), was without effect. 5. While CHAPS treatment significantly augmented the vasoconstrictor response to both noradrenaline and vasopressin in perfused renal and mesenteric vessels this effect was not mimicked by metyrapone or gossypol suggesting that the enhanced effect of vasopressor agents in CHAPSperfused rat organs is due to the removal of a permeability barrier rather than impaired EDRF formation. 6. Responses to vasoconstrictor and vasodilator drugs in the perfused kidney and mesentery were obtained in the presence of indomethacin (8 microM) which produced in excess of 90% inhibition of prostacyclin (PGI2) release as measured by radioimmunoassay of 6-oxo-prostaglandin F1 alpha,. (6-oxo- PGF1 alpha) in the Krebs effluent. 7. We provide evidence that EDRF mediates the vasodilator response to acetylcholine and histamine in resistance blood vessels in perfused rat kidney and mesentery. The possibility that EDRF has a physiological role to play in regulating the calibre of resistance blood vessels is discussed.

OBJECTIVE

Hepatic oxidative stress plays a key role in the development of non-alcoholic steatohepatitis (NASH). However, the protective effects of antioxidants on NASH are largely unknown. The aim of this study was to elucidate the effect and mechanism of antioxidants on NASH in mice.

METHODS

C57BL6/J mice were fed a methionine-choline-deficient (MCD) diet for 10 days or <em>3</em> weeks to induce steatohepatitis. Antioxidants (vitamin E, ABT, or vitamin E plus ABT) were supplemented in mice fed a MCD diet, respectively. The effect of antioxidants on oxidative stress and apoptosis was assessed, and activation of adiponectin and expressions of inflammatory factors, apoptosis-related genes, and fibrosis-related genes were assayed.

RESULTS

MCD feeding in mice showed increasing serum alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) levels, and progressive hepatic injury including hepatic steatosis and inflammatory infiltration. Administration of antioxidants vitamin E and/or ABT significantly lowered serum ALAT and ASAT levels (p<0.001) and ameliorated hepatic steatosis and necroinflammation. These effects were associated with repressed hepatic lipid peroxides through reducing hepatic MDA content and enhancing hepatic superoxide dismutase (SOD) activity; down-regulated inflammatory factor COX-2, lowered activity of NF-kappaB, up-regulated anti-apoptotic gene Bcl-2, and down-regulated pro-apoptotic gene Bax suppressed expression of the fibrotic genes TGF-beta1 and MMP2. Moreover, expression of the anti-inflammatory factor adiponectin was also induced by vitamin E or ABT. A combination of vitamin E and ABT showed an additive effect on preventing liver injury.

CONCLUSIONS

The present study provides morphological and molecular biological evidence for the protective role of the antioxidant vitamins E and ABT in ameliorating oxidative stress, hepatic apoptosis, and necroinflammation in experimental nutritional steatohepatitis.

We have examined the possible role of extracellular reduction-oxidation (redox) state in regulation of biological/biochemical features associated with prostate cancer cell invasion. DU145, PC-<em>3</em>, and RWPE1-derived human prostate cancer (WPE1-NB26) cell lines were used for the present in vitro analysis. Increasing levels of nitric oxide using S-nitroso-N-acetylpenicillamine resulted in a decrease in cell invasion ability, whereas increasing levels of extracellular superoxide radical (O(2)(*-)) using xanthine/xanthine oxidase resulted in an increase in cell invasion ability in these three cell lines. WPE1-NB26 cells exhibited an increased glutathione/glutathione disulfide ratio in the medium in comparison with RWPE1 cells (immortalized but nonmalignant prostate epithelial cells), suggesting an alteration of extracellular redox state of WPE1-NB26 cells. We hypothesized that O(2)(*-) production at or near the plasma membrane or in the adjacent extracellular matrix at least partially regulated prostate cancer cell invasion. Using adenovirus-mediated extracellular superoxide dismutase (EC-<em>SOD</em>) gene transduction to enzymatically decrease O(2)(*-) levels, we showed that in the presence of heparin, adenovirus EC-<em>SOD</em> gene transduction resulted in an increase in the expression of EC-<em>SOD</em> outside the cells with resultant inhibition of cell invasion ability. This inhibition correlated with reduced metalloproteinase [matrix metalloproteinase (MMP) 2/membrane type 1-MMP] activities and increased levels of extracellular nitrite. Our results suggest a prominent role of extracellular redox status in regulation of cell invasion, which may provide opportunities for therapeutic interventions.

In view of the antioxidant properties of melatonin, the effects of melatonin on the oxidative-antioxidative status of tissues affected by diabetes, e.g. liver, heart and kidneys, were investigated in streptozotocin (STZ)-induced diabetic rats in the present study. Concentrations of malondialdehyde (MDA) and reduced glutathione (GSH), and activities of superoxide dismutase (<em>SOD</em>) and glutathione peroxidase (GSH-Px) in the tissues were compared in three groups of 10 rats each (control non-diabetic rats (group I), untreated diabetic rats (group II) and diabetic rats treated with melatonin (group III)). In the study groups, diabetes developed <em>3</em> days after intraperitoneal (i.p.) administration of a single 60 mg kg(-1) dose of STZ. Thereafter, while the rats in group II received no treatment, the rats in group III began to receive a 10 mg kg(-1) i.p. dose of melatonin per day. After 6 weeks, the rats in groups II and III had significantly lower body weights and higher blood glucose levels than the rats in group I (p < 0.001 and p < 0.001, respectively). MDA levels in the liver, kidney and heart of group II rats were higher than that of the control group (p < 0.01, p < 0.05, p < 0.01, respectively) and diabetic rats treated with melatonin (p < 0.05). The GSH, GSH-Px and <em>SOD</em> levels increased in diabetic rats. Treatment with melatonin changed them to near control values. Our results confirm that diabetes increases oxidative stress in many organs such as liver, kidney and heart and indicate the role of melatonin in combating the oxidative stress via its free radical-scavenging and antioxidant properties.

Methylglyoxal (MG) is a physiological metabolite, but it is known to be toxic, inducing stress and causing apoptosis. Our previous studies demonstrated that MG induced apoptosis in Jurkat cells by activating the c-Jun N-terminal kinase (JNK) signal transduction pathway, which induced an obvious decrease in mitochondrial membrane potential, followed by caspase-<em>3</em> activation. Here, we observed that MG-induced apoptosis was associated with both rapid production of superoxide anion (O(2)(-)) followed by a marked increase in ROS and striking and temporal activation of ASK1. Overexpression of wild-type ASK1 could enhance the rate of apoptosis induced by MG, whereas the expression of the kinase-inactive form of ASK1 notably prevented cells from MG-induced death. NAC and PDTC blocked the activation of ASK1 and MG-induced apoptosis completely. Moreover, nonthiol antioxidants <em>SOD</em>-mimic MnTBAP and catalase together obviously inhibited MG-induced ASK1 activation and apoptosis induction. Correspondingly, MG-mediated ASK1 activation was enhanced by diethyldithiocarbamate (DDC). Addition of antioxidant into the culture of cells at a later stage (4-8 h after the initial MG treatment) failed to prevent their death. These results suggest that activating ASK1 at the early stage linking to production of O(2)(-) is crucial for subsequent progression of apoptosis in MG-treated Jurkat cells.

When a defect occurs in the in vitro development of a pronuclear embryo, the interruption of the subsequent implantation limits the success of assisted conception. This common problem remains to be solved. In this study, we observed that melatonin at its physiological concentration (10(-7) m) significantly promoted the in vitro development of murine pronuclear embryos. This was indicated by the increased blastocyst rate, hatching blastocyst rate, and blastocyst cell number with melatonin treatment. In addition, when these blastocysts were implanted into female recipient mice, the pregnancy rates (95.0% versus control 67.8%), litter sizes (4.1 pups/litter versus control 2.7 pups/litter), and postnatal survival rates of offspring (96.84% versus control 81.24%) were significantly improved compared with their non-melatonin-treated counterparts. Mechanistic studies revealed that melatonin treatment upregulates gene expression of the antioxidant enzyme, superoxide dismutase (<em>SOD</em>), and the anti-apoptotic factor bcl-2 while downregulating the expression of pro-apoptotic genes p5<em>3</em> and caspase-<em>3</em>. Due to these changes, melatonin treatment reduces ROS production and cellular apoptosis during in vitro embryo development and improves the quality of blastocysts. The implantation of blastocysts with higher quality leads to more healthy offspring and increased pup survival.

Calcific aortic stenosis displays some similarities to atherosclerosis including evidence of endothelial dysfunction. Whether nitric oxide (NO), which is produced by valvular endothelium, has direct protective effects extending to calcification processes in aortic valve cells has not previously been examined. In vitro calcifying nodules in porcine aortic valve interstitial cell cultures, formed in response to transforming growth factor-beta1 (TGF-beta1) 5 ng/ml, were inhibited by NO donors DETA-NONOate 5-100 microM, and sodium nitroprusside (SNP) <em>3</em> microM. Raising intracellular cGMP concentrations, via 8-bromo cGMP 1 mM or via brain natiuretic peptide and C-type natiuretic peptide 0.1 microM, inhibited TGF-beta1-induced nodule formation, potentially implicating the cGMP pathway in the NO effect. Stimulation of interstitial cells with substance P or calcium ionophone (A2<em>3</em>187) caused NO release and increased intracellular cGMP respectively. However in the presence of TGF-beta1 basal levels of NO production via nitric oxide synthase (NOS) were insufficient to affect nodule formation. Increased dihydroethidium (DHE) fluorescence in response to TGF-beta1, which was inhibited by DETA-NONOate and TEMPOL, suggested a role for intracellular superoxide in TGF-beta1 signalling. Moreover, nodule formation was suppressed by superoxide scavengers TEMPOL, hydralazine and polyethylene glycol-superoxide dismutase (PEG-<em>SOD</em>), but not <em>SOD</em>. In conclusion, NO donors, or agents raising intracellular cGMP levels, may protect aortic valve interstitial cells from early events leading to calcification.

The effects of lead ingestion on parameters indicative of copper status, and particularly on the activity of the copper-dependent metalloenzyme superoxide dismutase (<em>SOD</em>) in erythrocytes, were investigated in weanling and neonatal rats. In a series of experiments, Sprague-Dawley or Long-Evans rats were fed a nutritionally adequate purified diet (AIN-'76). Lead acetate was given orally in the drinking water (0, 100, 250, or 500 ppm Pb) to groups of 2<em>3</em> to 26-day-old rats for 5 weeks or intragastrically (0, 5, 11, 22, or 45 mg Pb/kg body wt/day) to pups from postnatal Days 2 through 20. Lead ingestion (250 and 500 ppm Pb) by weanling rats resulted in decreased concentrations of copper in blood (erythrocytes and serum), liver, and spleen, in increased concentrations of iron in liver and spleen, in increased spleen weight, and in a small decrease in hemoglobin and hematocrit values. There was a significant decrease in the activities of the copper metalloproteins erythrocyte superoxide dismutase (<em>SOD</em>) and serum ceruloplasmin (Cp). In contrast, in the neonate we found no significant effects of lead on copper concentrations in blood or tissue or on other measures indicative of copper status. Despite high blood lead concentrations (1-<em>3</em> micrograms/ml), <em>SOD</em> activity was not decreased in the neonatal rat. In addition, lead had no direct effect in vitro on the activity of bovine blood superoxide dismutase. On the basis of both the in vitro and in vivo studies, it appears likely that the observed decrease in <em>SOD</em> in young rats is caused indirectly by a lead-induced copper deficiency rather than by a direct inhibitory effect of lead.

The purpose of this study was to investigate the effects of dietary NiCl2 on antioxidant function, apoptosis, and the protein expression, mRNA expression and contents of the bcl-2, bax and caspase-<em>3</em> in the cecal tonsil of broilers. 280 one-day-old avian broilers were divided into four groups and fed on a corn-soybean basal diet as control diet or the same basal diet supplemented with <em>3</em>00, 600 and 900 mg/kg of NiCl2 for 42 days. The activities of <em>SOD</em>, CAT and GSH-Px, and the ability to inhibit hydroxy radical, and GSH content were significantly decreased in all experimental groups. MDA content was significantly increased. The protein expression, mRNA expression and contents of bcl-2 were decreased, and bax and caspase-<em>3</em> were increased in all experimental groups. The percentages of apoptotic lymphocytes were significantly increased. In conclusion, dietary NiCl2 in excess of <em>3</em>00 mg/kg caused oxidative stress, and then induced decreased the protein expression, mRNA expression and the contents of bcl-2, and increased protein expression, mRNA expression and the contents of bax and caspase-<em>3</em> proteins in the cecal tonsil. The local intestinal mucosal immunity could finally be impaired due to the oxidative stress and apoptosis in the cecal tonsil caused by NiCl2.

BACKGROUND

Primary pathology underlying Parkinson's disease (PD) is the loss of dopaminergic neurons in the substantia nigra (SN). A variety of genetic and environmental factors underlie this loss of dopaminergic neurons. However, recent studies have highlighted the role of elevated oxidative stress and the pro-inflammatory responses contributing to or exacerbating the nigrostriatal degeneration.

METHODS

With the establishment of neuroinflammation as an important process involved in the PD pathogenesis, in the present study this pathogenic feature was replicated in animals using lipopolysaccharide (LPS) (5 ug/5 ul PBS) infused stereotaxically into the SN of rats.

RESULTS

LPS injected into the SN successfully replicated the pathogenic features of PD in rats as it elicited an inflammatory response via action of microglia. LPS infusion resulted in glial cell activation as depicted from immunohistochemistry (IHC) analysis of GFAP and Iba-1. Also, a significant increase in the mRNA expression of proinflammatory cytokines, i.e. TNF-α and IL-1β, was observed after 7 days of LPS infusion whereas the alterations in the oxidative stress markers, i.e ROS, lipid peroxidation, NO formation, NADPH oxidase activity, glutathione system, <em>SOD</em> and catalase, became highly significant after 14 days of infusion. As a consequence, after 21 days of LPS infusion we observed activation of apoptotic pathway indicated by increased expression of caspases <em>3</em> and caspase 9. This was followed by a significant decline in the expression of tyrosine hyroxylase (TH) as revealed by IHC. Further, there was a marked decrease in the level of dopamine and its metabolites enough for the production of behavioral abnormality in rats.

CONCLUSIONS

Hence, the present study provides extensive characterization of LPS induced model of PD. Study also confirms the co-existence and complex interplay between inflammation and oxidative stress contributing equally to the dopaminergic neuronal degeneration process in PD.

OBJECTIVE

The risk for cardiovascular disease is significantly high in diabetes mellitus. Experimental evidence suggests that oxidative stress plays a dominant role in the pathogenesis of diabetes mellitus. Caffeic acid phenethyl ester (CAPE), an active component of propolis, has several biological and pharmacological properties, including antioxidant, anti-inflammatory, anti-carcinogenic, antiviral, and immunomodulatory activities. In light of the antioxidant ability of CAPE, the effects of CAPE on the antioxidative status of cardiac tissue were investigated in streptozotocin (STZ)-induced diabetic rats.

METHODS

Twenty-six rats were randomly divided into three groups: group I, control, nondiabetic rats (n = 9); group II, STZ-induced, untreated diabetic rats (n = 7); and group III, STZ-induced, CAPE-treated diabetic rats (n = 10). In groups II and III, diabetes developed <em>3</em> days after intraperitoneal (ip) administration of a single <em>3</em>5 mg kg(-1) dose of STZ. Thereafter, while the rats in group II received no treatment, the rats in group III began to receive a 10 mumol kg(-1) ip dose of CAPE per day. After 8 weeks, the levels of malondialdehyde (MDA) and the activities of superoxide dismutase (<em>SOD</em>), catalase (CAT), and glutathione peroxidase (GSH-Px) in the cardiac tissues of all groups were analyzed.

RESULTS

In untreated diabetic rats, MDA markedly increased in the cardiac tissue compared with the control rats (P < 0.05). However, MDA levels were reduced to the control level by CAPE. The activities of SOD and CAT in the untreated diabetic group and the CAPE-treated diabetic group were higher than those of the control group (P < 0.05). Rats in the CAPE-treated diabetic group had reduced activities of SOD and CAT in comparison with the rats in the untreated diabetic group (P < 0.05). There were no significant differences in the activity of GSH-Px between the rats in the untreated diabetic group and the control group. However, the activity of GSH-Px was increased in CAPE-treated diabetic rats compared with the control and untreated diabetic rats (P < 0.05).

CONCLUSIONS

These results reveal that diabetes mellitus increases oxidative stress in cardiac tissue and CAPE has an ameliorating effect on the oxidative stress via its antioxidant property.

The effect of intermittent sprint cycle training on the level of muscle antioxidant enzyme protection was investigated. Resting muscle biopsies, obtained before and after 6 wk of training and <em>3</em>, 24, and 72 h after the final session of an additional 1 wk of more frequent training, were analyzed for activities of the antioxidant enzymes glutathione peroxidase (GPX), glutathione reductase (GR), and superoxide dismutase (<em>SOD</em>). Activities of several muscle metabolic enzymes were determined to assess the effectiveness of the training. After the first 6-wk training period, no change in GPX, GR, or <em>SOD</em> was observed, but after the 7th week of training there was an increase in GPX from 120 +/- 12 (SE) to 164 +/- 24 mumol.min-1.g dry wt-1 (P < 0.05) and in GR from 10.8 +/- 0.8 to 16.8 +/- 2.4 mumol.min-1.g dry wt-1 (P < 0.05). There was no significant change in <em>SOD</em>. Sprint cycle training induced a significant (P < 0.05) elevation in the activity of phosphofructokinase and creatine kinase, implying an enhanced anaerobic capacity in the trained muscle. The present study demonstrates that intermittent sprint cycle training that induces an enhanced capacity for anaerobic energy generation also improves the level of antioxidant protection in the muscle.

Dietary isoflavone intake has been linked to cancer prevention and their anti-inflammation activity was examined. Intraperitoneal lipopolysaccharide (LPS) injection in mice led to a decrease in the liver antioxidant glutathione level but this decrease was prevented in mice fed with an isoflavone-containing diet. Similarly, isoflavone diet prevented the inflammation-associated induction of metallothionein (MT) in the intestine; and the induction of manganese superoxide dismutase (Mn-<em>SOD</em>) in the liver. Results from the intestinal cell studies suggest that isoflavones suppress the intestinal response to inflammation by modulating the action of pro-inflammatory cytokine, IL-6. IL-6 secretion and the STAT<em>3</em> (signal transducer and activator of transcription protein <em>3</em>) nuclear translocation in response to IL-6 were both decreased by genistein.

The aim of the present study was to investigate the protective effects of (-)-epigallocatechin-<em>3</em>-gallate (EGCG), the main polyphenolic constituent of green tea, in aging mice induced by D-galactose (D-gal). The aging mice model was induced by subcutaneous (s.c.) injection of D-gal (150 mg/kg) once daily for 6 weeks. EGCG (2 mg/kg or 6 mg/kg) was administered intragastrically (i.g.) once daily for 4 weeks after 2-week D-gal injection. The water maze test was used to evaluate the learning and memory function of mice. The activities of total superoxide dismutase (T-<em>SOD</em>) and glutathione peroxidase (GSH-Px) and the contents of malondialdehyde (MDA) in the hippocampus were measured using different biochemical kits to estimate the changes in the antioxidative ability of mice. TdT-mediated dUTP-biotin nick end labeling (TUNEL) staining method was used to detect neuronal apoptosis, and the activation and expression of proapoptotic protein caspase-<em>3</em> in the hippocampus were observed and analyzed using immunohistochemical staining and the Western blot method to evaluate apoptosis in the brain. The results indicated that subcutaneous injection of D-gal induced learning and memory impairment in mice, decreased T-<em>SOD</em> and GSH-Px activities, increased MDA contents in the hippocampus, and increased the cell apoptosis index and cleaved caspase-<em>3</em> protein expression in the hippocampus. Oral administration of EGCG (2 mg/kg or 6 mg/kg) for 4 weeks significantly improved the cognitive deficits in mice and elevated T-<em>SOD</em> and GSH-Px activities, decreased MDA contents in the hippocampus, and reduced the cell apoptosis index and expression of cleaved caspase-<em>3</em> in the mouse hippocampus. The results suggest that EGCG has potent neuroprotective effects on aging mice induced by D-gal through antioxidative and antiapoptotic mechanisms, indicating that EGCG is worthy of further study in aging.

Over-expression of mutant copper, zinc superoxide dismutase (<em>SOD</em>) in mice induces ALS and has become the most widely used model of neurodegeneration. However, no pharmaceutical agent in 20 years has extended lifespan by more than a few weeks. The Copper-Chaperone-for-<em>SOD</em> (CCS) protein completes the maturation of <em>SOD</em> by inserting copper, but paradoxically human CCS causes mice co-expressing mutant <em>SOD</em> to die within two weeks of birth. Hypothesizing that co-expression of CCS created copper deficiency in spinal cord, we treated these pups with the PET-imaging agent CuATSM, which is known to deliver copper into the CNS within minutes. CuATSM prevented the early mortality of CCSx<em>SOD</em> mice, while markedly increasing Cu, Zn <em>SOD</em> protein in their ventral spinal cord. Remarkably, continued treatment with CuATSM extended the survival of these mice by an average of 18 months. When CuATSM treatment was stopped, these mice developed ALS-related symptoms and died within <em>3</em> months. Restoring CuATSM treatment could rescue these mice after they became symptomatic, providing a means to start and stop disease progression. All ALS patients also express human CCS, raising the hope that familial <em>SOD</em> ALS patients could respond to CuATSM treatment similarly to the CCSx<em>SOD</em> mice.

1. The involvement of nitric oxide (NO) in the regulation of angiogenesis was examined in the in vivo system of the chorioallantoic membrane (CAM) of the chick embryo and in the matrigel tube formation assay. 2. Sodium nitroprusside (SNP) (0.<em>3</em>7-28 nmol/disc), which releases NO spontaneously, caused a dose-dependent inhibition of angiogenesis in the CAM in vivo and reversed completely the angiogenic effects of alpha-thrombin (6.7 nmol/disc) and the protein kinase C (PKC) activator 4-beta-phorbol-12-myristate-1<em>3</em>-acetate (PMA) (0.97 nmol/disc). In addition, SNP (28 x 10(-6) M) stimulated the release of guanosine <em>3</em>'-5'-cyclic monophosphate (cyclic GMP) from the CAM in vitro. <em>3</em>. In the matrigel tube formation assay, an in vitro assay of angiogenesis, both SNP (1-<em>3</em> x 10(-6) M) and the cell permeable cyclic GMP analogue, Br-cGMP (0.<em>3</em>-1.0 x 10(-<em>3</em>) M) reduced tube formation. 4. The inhibitors of NO synthase, NG-monomethyl-L-arginine (L-NMMA) (<em>3</em>.8-102 nmol/disc) and NG-nitro-L-arginine methylester (L-NAME) (1.<em>3</em>-<em>3</em>4.2 nmol/disc) stimulated angiogenesis in the CAM in vivo, in a dose-dependent fashion. D-NMMA and D-NAME on the other hand had no effect on angiogenesis in this system. 5. L-Arginine (10.9 nmol/disc), although it had a modest antiangiogenic effect by itself, was capable of abolishing the angiogenic effects of L-NMMA (<em>3</em>4.2 nmol/disc) and of L-NAME (<em>3</em>.8 nmol/disc). 6. Dexamethasone, an inhibitor of the induction of NO synthase, at 0.2-116.1 nmol/disc, stimulated angiogenesis in the CAM, whereas at <em>3</em>48.4-1161 nmol/disc it inhibited this process. Combination of <em>3</em>8.7 nmol/disc dexamethasone with L-NAME (9.<em>3</em> nmol/disc) resulted in a potentiation of the angiogenic effect of the former. It appears therefore that both the constitutive and the inducible NO synthase may contribute to the NO-mediated inhibition of angiogenesis. 7. Superoxide dismutase (<em>SOD</em>), which prevents the destruction of NO, at <em>3</em>00 i.u./disc had a modest antiangiogenic effect in the CAM, by itself. In addition, <em>SOD</em>, prevented alpha-thrombin (6.7 nmol/disc) and PMA (0.97 nmol/disc) from stimulating angiogenesis in the CAM.8. These results suggest that NO may be an endogenous antiangiogenic molecule of pathophysiological importance.

The main objective of the present study was to investigate possible links between biomarkers and swimming performance in the estuarine fish Pomatoschistus microps acutely exposed to metals (copper and mercury). In independent bioassays, P. microps juveniles were individually exposed for 96 h to sub-lethal concentrations of copper or mercury. At the end of the assays, swimming performance of fish was measured using a device specially developed for epibenthic fish (SPEDE). Furthermore, the following biomarkers were measured: lipid peroxidation (LPO) and the activity of the enzymes acetylcholinesterase (AChE), lactate dehydrogenase (LDH), glutathione S-transferases (GST), 7-ethoxyresorufin-O-deethylase (EROD), superoxide dismutase (<em>SOD</em>), catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GPx). LC(50)s of copper and mercury (dissolved throughout metal concentrations) at 96h were 568 microg L(-1), and 62 microg L(-1), respectively. Significant and concentration-dependent effects of both metals on swimming resistance and covered distance against water flow were found at concentrations equal or higher than 50 microg L(-1) for copper and <em>3</em> microg L(-1) for mercury (dissolved throughout metal concentrations). These results indicate that SPEDE was efficacious to quantify behavioural alterations in the epibenthic fish P. microps at ecologically relevant concentrations. Significant alterations by both metals on biomarkers were found including: inhibition of AChE and EROD activities, induction of LDH, GST and anti-oxidant enzymes, and increased LPO levels, with LOEC values ranging from 25 to 200 microg L(-1), for copper and from <em>3</em> to 25 microg L(-1) for mercury (dissolved throughout metal concentrations). Furthermore, significant and positive correlations were found between some biomarkers (AChE and EROD) and behavioural parameters, while negative correlations were found for others (LPO, anti-oxidant enzymes and LDH) suggesting that disruption of cholinergic function through AChE inhibition, decreased detoxification capability due to EROD inhibition, additional energetic demands to face chemical stress, and oxidative stress and damage may contribute to decrease the swimming performance of fish. Since a reduced swimming capability of fish may reduce their ability to capture preys, avoid predators, and interfere with social and reproductive behaviour, the exposure of P. microps to copper and/or mercury concentrations similar to those tested here may decrease the fitness of wild populations of this species.

The present study was conducted to evaluate in vitro and in vivo the antioxidant and anti-inflammatory properties of a cantaloupe melon (Cucumis melo LC., Cucurbitaceae) extract (CME) selected for its high superoxide dismutase activity. Peritoneal macrophages were pre-activated in vitro with <em>3</em>00 IU of interferon-gamma (IFN-gamma) and were then challenged in culture with IgGl/anti-IgG1 immune complexes (IgG1IC) in presence of various CME extracts. The subsequent production of free radicals (superoxide anion, nitric oxide, and peroxynitrite) and of pro-(TNF-alpha) and anti-(IL-10) inflammatory cytokines was evaluated. The CME inhibited in a dose-dependent manner the production of superoxide anion with a maximal effect at 100 microg/ml. This inhibitory effect of CME appeared to be closely linked to the <em>SOD</em> activity because it was dramatically decreased after heat inactivation of the <em>SOD</em> activity (HI-CME). In addition, the CME inhibited the production of peroxynitrite strengthening the antioxidant properties of this CME rich in <em>SOD</em> activity. The production of the pro- and anti-inflammatory cytokines, namely TNF-alpha and IL-10, being conditioned by the redox status of macrophages we also evaluated the effect of CME and HI-CME on the IgG1IC-induced cytokine production. When the <em>SOD</em> activity was present in the CME it promoted the IgG1IC-induced production of IL-10 instead of TNF-alpha. These data demonstrated that, in addition to its antioxidant properties, the anti-inflammatory properties of the CME extract were principally related to its capacity to induce the production of IL-10 by peritoneal macrophages. The particular properties of wheat gliadin (Triticum vulgare, Poaceae) for the oral delivery of functional proteins led us to test it in a new nutraceutical formula based on its combination with the CME thus monitoring the <em>SOD</em> activity release during the gastro-intestinal digestive process. In these experiments C57BL/6 mice were supplemented orally everyday during 28 days with: (1) the placebo, (2) the CME extract alone, (<em>3</em>) the gliadin, (4) the CME/gliadin combination, or (5) the HI-CME/gliadin combination (<em>SOD</em> inactivated). At the end of the supplementation period all the animals were injected intra-peritoneal (i.p.) with the pro-inflammatory cytokine IFN-gamma (<em>3</em>00 IU) and peritoneal macrophages were harvested 24 h after to test their capacities to produce free radicals, TNF-alpha and IL-10 after triggering with IgG1IC. We demonstrated that animals supplemented during 28 days with the CME/gliadin combination were protected against the pro-inflammatory properties of IFN-gamma while the other products were inefficient. These data did not only indicate that the <em>SOD</em> activity is important for the antioxidant and anti-inflammatory properties of the CME extract, but also demonstrated that when the <em>SOD</em> activity is preserved during the digestive process by its combination with wheat gliadin it is possible to elicit in vivo the pharmacological effects of this antioxidant enzyme.

High dietary fructose is an important causative factor in the development of metabolic syndrome-associated glomerular podocyte oxidative stress and injury. Here, we identified microRNA-<em>3</em>77 (miR-<em>3</em>77) as a biomarker of oxidative stress in renal cortex of fructose-fed rats, which correlated with podocyte injury and albuminuria in metabolic syndrome. Fructose feeding increased miR-<em>3</em>77 expression, decreased superoxide dismutase (<em>SOD</em>) expression and activity, and caused O2(-) and H2O2 overproduction in kidney cortex or glomeruli of rats. This reactive oxygen species induction increased p<em>3</em>8 MAPK phosphorylation and thioredoxin-interacting protein (TXNIP) expression and activated the NOD-like receptor pyrin domain-containing <em>3</em> (NLRP<em>3</em>) inflammasome to produce interleukin-1β in kidney glomeruli of fructose-fed rats. These pathological processes were further evaluated in cultured differentiated podocytes exposed to 5mM fructose, or transfected with miR-<em>3</em>77 mimic/inhibitor and TXNIP siRNA, or co-incubated with p<em>3</em>8 MAPK inhibitor, demonstrating that miR-<em>3</em>77 overexpression activates the O2(-)/p<em>3</em>8 MAPK/TXNIP/NLRP<em>3</em> inflammasome pathway to promote oxidative stress and inflammation in fructose-induced podocyte injury. Antioxidants pterostilbene and allopurinol were found to ameliorate fructose-induced hyperuricemia, podocyte injury, and albuminuria in rats. More importantly, pterostilbene and allopurinol inhibited podocyte miR-<em>3</em>77 overexpression to increase <em>SOD</em>1 and <em>SOD</em>2 levels and suppress the O2(-)/p<em>3</em>8 MAPK/TXNIP/NLRP<em>3</em> inflammasome pathway activation in vivo and in vitro, consistent with the reduction of oxidative stress and inflammation. These findings suggest that miR-<em>3</em>77 plays an important role in glomerular podocyte oxidative stress, inflammation, and injury driven by high fructose. Inhibition of miR-<em>3</em>77 by antioxidants may be a promising therapeutic strategy for the prevention of metabolic syndrome-associated glomerular podocyte injury.