Turmeric has been in use since ancient times as a condiment and due to its medicinal properties. Curcumin, the yellow colouring principle in turmeric, is polyphenolic and major active constituent. Besides anti-inflammatory, thrombolytic and anticarcinogenic activities, curcumin also possesses strong antioxidant property. In view of the novel combination of properties, neuroprotective efficacy of curcumin was studied in rat middle cerebral artery occlusion (MCAO) model. Rats were subjected to 2 h of focal ischemia followed by 72 h of reperfusion. They were pre-treated with curcumin (100 mg/kg, po) for 5 days prior to MCAO and for another <em>3</em> days after MCAO. The parameters studied were behavioural, biochemical and histological. Treatment with curcumin could significantly improve neurobehavioral performance compared to untreated ischemic rats as judged by its effect on rota-rod performance and grid walking. A significant inhibition in lipid peroxidation and an increase in superoxide dismutase (<em>SOD</em>) activity in corpus striatum and cerebral cortex was observed following treatment with curcumin in MCAO rats as compared to MCAO group. Intracellular calcium levels were decreased following treatment with curcumin in MCAO rats. Histologically, a reduction in the infarct area from <em>3</em><em>3</em>% to 24% was observed in MCAO rats treated with curcumin. The study demonstrates the protective efficacy of curcumin in rat MCAO model.

The aim of the present study was to evaluate the effects of Quercetin (Qctn), a plant based flavonol, on retinal oxidative stress, neuroinflammation and apoptosis in streptozotocin-induced diabetic rats. Qctn treatment (25- and 50 mg/kg body weight) was given orally for six months in diabetic rats. Retinal glutathione (GSH) and antioxidant enzymes [superoxide dismutase (<em>SOD</em>) and catalase (CAT)] were estimated using commercially available assays, and inflammatory cytokines levels [tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β)] were estimated by ELISA method. Immunofluorescence and western blot studies were performed for nuclear factor kappa B (NF-kB), caspase-<em>3</em>, glial fibrillary acidic protein (GFAP) and aquaporin-4 (AQP4) expressions. Structural changes were evaluated by light microscopy. In the present study, retinal GSH levels and antioxidant enzyme (<em>SOD</em> and CAT) activities were significantly decreased in diabetic group as compared to normal group. However, in Qctn-treated rats, retinal GSH levels were restored close to normal levels and positive modulation of antioxidant enzyme activities was observed. Diabetic retinas showed significantly increased expression of pro-inflammatory cytokines (TNF-α and IL-1β) as compared to that in normal retinas, while Qctn-treated retinas showed significantly lower levels of cytokines as compared to diabetic retinas. Light microscopy showed significantly increased number of ganglion cell death and decreased retinal thickness in diabetic group compared to those in normal retina; however, protective effect of Qctn was seen. Increased apoptosis in diabetic retina is proposed to be mediated by overexpression of NF-kB and caspase-<em>3</em>. However, Qctn showed inhibitory effects on NF-kB and caspase-<em>3</em> expression. Microglia showed upregulated GFAP expression, and inflammation of Müller cells resulted in edema in their endfeet and around perivascular space in nerve fiber layer in diabetic retina, as observed through AQP4 expression. However, Qctn treatments inhibited diabetes-induced increases in GFAP and AQP4 expression. Based on these findings, it can be concluded that bioflavonoids, such as Qctn can be effective for protection of diabetes induced retinal neurodegeneration and oxidative stress.

BACKGROUND

Antioxidant, antiproliferative and apoptosis inducing activities of a natural polyphenolic compound, ellagic acid, were studied.

METHODS

DPPH radical scavenging and lipid peroxidation inhibitory activities were observed. Activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) were measured in ellagic acid-treated V79-4 cells. For apoptotic inducing activity, human osteogenic sarcoma (HOS) cell proliferation, chromosomal DNA degradation and changes in apoptosis-related protein levels were measured.

RESULTS

Ellagic acid showed high DPPH radical scavenging and lipid peroxidation inhibition activities. SOD, CAT and GPX activities were significantly increased in ellagic acid-treated V79-4 cells. Ellagic acid significantly reduced HOS cell proliferation, and induced apoptosis evidenced by chromosomal DNA degradation and apoptotic body appearance. Bax expression was induced and caspase-3 was activated by ellagic acid treatment.

CONCLUSIONS

Ellagic acid exhibited both antioxidant activity in V79-4 cells and apoptosis-inducing activity in HOS cells through the up-regulation of Bax and activation of caspase-3.

BACKGROUND

To investigate the cardiotoxic role of reactive oxygen species (ROS) and of products derived from catecholamines auto-oxidation, we studied: (1) the response of antioxidant cardiac cellular defence systems to oxidative stress induced by norepinephrine (NE) administration, (2) the effect of NE administration on cardiac beta1-adrenergic receptors by means of receptor binding assay, (<em>3</em>) the cellular morphological alterations related to the biologically cross-talk between the NE administration and cytokines [tumor necrosis factor-alpha (TNF-alpha), monocyte chemotactic protein-1 (MCP-1), interleukins IL6, IL8, IL10].

RESULTS

A total of 195 male rats was used in the experiment. All animals underwent electrocardiogram (EKG) before being sacrificed. The results obtained show that NE administration influences the antioxidant cellular defence system significantly increasing glutathione peroxidase (GPx) activity, glutathione reductase (GR) and superoxide dismutase (SOD). The oxidized glutathione (GSH/GSSG) ratio significantly decreases and malondialdehyde (MDA) levels increase showing a state of lipoperoxidation of cardiac tissue. We describe a significant apoptotic process randomly sparse in the damaged myocardium and the effect of ROS on the NE-mediated TNF-alpha, MCP-1, and IL6, IL8, IL10 production.

CONCLUSIONS

Our results support the hypothesis that catecholamines may induce oxidative damage through reactive intermediates resulting from their auto-oxidation, irrespective of their interaction with adrenergic receptors, thus representing an important factor in the pathogenesis of catecholamines-induced cardiotoxicity. The rise of the cardioinhibitory cytokines may be interpreted as the adaptive response of jeopardized myocardium with respect to the cardiac dysfunction resulting from NE injection.

The objective of this experiment was to investigate the influence of weaning stress and an antioxidant blend on gut health and free radical metabolism in postweaning pigs. A total of 96 pigs from 12 litters were randomly divided by litter to <em>3</em> groups with 4 litters each. The control group and the weaning group were fed the basal diet, and the antioxidant group was fed the basal diet supplemented with an antioxidant blend. The control group was suckling normally during the experimental period and the other 2 treatments were weaned at 21 d of age. Morphology in different parts of the intestines was used as a measure of intestinal barrier function. Activities of superoxide dismutase (<em>SOD</em>), glutathione peroxidase (GSH-Px), and the concentrations of malondialdehyde (MDA), NO, H(2)O(2), and O(2) were measured in serum. Activities of the digestive enzymes, including sucrase, maltase, amylase, lipase, and pepsin, were measured at 24 d of age for all treatments. Gene expressions of free radicals, digestive enzymes, or antioxidant enzymes were selected for quantitative reverse transcription-PCR analyses. Results showed that weaning resulted in reductions (P < 0.05) in the villus height and width, and activity of digestive enzymes. Activity of <em>SOD</em> decreased (P < 0.05) and the concentrations of MDA, NO, and H(2)O(2) increased (P < 0.05) after weaning. The expression results indicated that the genes related to the antioxidant enzymes and digestive enzymes were down regulated (P < 0.05) after weaning. Tumor protein 5<em>3</em>, which regulates reactive oxygen-species generation, tended to increase (P < 0.10) in the weaning group. The concentration of PPARγ coactivator-1α (PGC-1α), which plays an important protective role against oxidative stress by regulating the expression of mitochondrial antioxidants, was reduced (P < 0.05) in weaning pigs and increased (P < 0.01) in antioxidant pigs compared with the control pigs. Results indicated that intestinal dysfunction occurred after weaning and there was an inhibition of the antioxidant system. The antioxidant blend has the potential to prevent free radical-induced damage and suppress oxidative stress by modulating the expressions of tumor protein 5<em>3</em> and PGC-1α genes.

Aldosterone (Aldo) stimulates glomerular mesangial cell (MC) proliferation, in part, through an ERK1/2-dependent pathway. In this study, we examined whether Aldo activation of ERK1/2 in MC is mediated through redox-dependent EGF receptor (EGFR) transactivation, as well as the involvement of other signaling mechanisms in Aldo-induced MC proliferation. Aldo increased human MC proliferation, as determined by [(<em>3</em>)H]thymidine incorporation and cell counts. This increase in proliferation was blocked by inhibition of the mineralocorticoid receptor (MR). Continuing our observations downstream in the signaling pathway, we examined the ability of Aldo to activate both the Ras/MAPK and the PI<em>3</em>K signaling pathways. Aldo increased Ki-RasA and Ki-RasA:GTP levels, and sequentially phosphorylated c-Raf, MAPK kinase (MEK1/2), and ERK1/2. Ki-RasA small interfering RNA (siRNA), the c-Raf inhibitor GW5074, and the MEK1/2 inhibitor PD98059 reduced Aldo-induced cell proliferation by approximately 65%. Aldo also increased phosphorylation of PI<em>3</em>K, Akt, the mammalian target of rapamycin (mTOR), and the 70-kDa ribosomal S6 kinase (p70S6K1). Inhibition of the PI<em>3</em>K pathways by the selective PI<em>3</em>K inhibitor LY 294002, an Akt inhibitor, or the mTOR inhibitor rapamycin reduced cell proliferation by 51%. Combining LY 294002 and PD98059 completely blocked Aldo-induced MC proliferation. Next, we confirmed that Aldo exerts its effect on MAPK and PI<em>3</em>K activation, as well as on cell proliferation, by activating the EGFR. Pretreatment with the EGFR antagonist AG1478 inhibited MC proliferation, as well as the activation of Ras/MAPK and PI<em>3</em>K/Akt, suggesting that Ras/MAPK and PI<em>3</em>K/Akt activation occur downstream of EGFR activation. Finally, we examined the role of reactive oxygen species (ROS) in Aldo-induced transactivation of the EGFR. Aldo-induced ROS were predominantly generated by mitochondria. Pretreatment with the antioxidant N-acetyl-l-cysteine, catalase, <em>SOD</em>, mitochondrial respiratory chain complex I inhibitor rotenone (Rot), NADPH oxidase inhibitor apocynin, and DPI significantly inhibited Aldo-stimulated MC proliferation as well as EGFR transactivation. However, Rot reduced MC proliferation more potently than apocynin and DPI. In conclusion, Aldo stimulated cell proliferation through MR-mediated, redox-sensitive EGFR transactivation, which was dependent on the Ki-RasA/c-Raf/MEK/ERK and PI<em>3</em>K/Akt/mTOR/p70S6K1 signaling pathways in human MCs.

Gallium-arsenide (GaAs) and helium-neon (HeNe) lasers are the most commonly used low-energy lasers in physiotherapy for promoting wound healing and pain modulation. The aim of this study was investigate the effect of low-power laser irradiation (LPLI) at different wavelengths and doses on oxidative stress and fibrogenesis parameters in an animal model of wound healing. The animals were randomly divided into five groups (n=6): Controls (skin injured animals without local or systemic treatment), skin injury treated with HeNe 1 J/cm(2) (two seg); skin injury treated with HeNe <em>3</em> J/cm(2) (six seg); skin injury treated with GaAs 1 J/cm(2) (three seg); skin injury treated with GaAs <em>3</em> J/cm(2) (nine seg). A single circular wound measuring 8 mm in diameter was surgically created on the back of the animal. The rats were irradiated at 2, 12, 24, 48, 72, 96, and 120 h after skin injury. The parameters, namely hydroxyproline content, activities of the antioxidant enzymes superoxide dismutase (<em>SOD</em>) and catalase (CAT), and lipid (TBARS) and protein oxidation (carbonyl groups) measurements were assessed. In addition, wound size regression was also analyzed. The results showed an improvement in the wound healing reflected by the reduction in wound size and increased collagen synthesis. Moreover, a significant reduction in TBARS levels, carbonyl content, and <em>SOD</em> and CAT activities were observed after laser irradiation, particularly with the treatments HeNe laser 1 and <em>3</em> J/cm(2) dose and GaAs <em>3</em> J/cm(2) dose. The data strongly indicate that LPLI therapy is efficient in accelerating the skin wound healing process after wounding, probably by reducing the inflammatory phase and inducing collagen synthesis.

BACKGROUND

The mechanisms of particulate matter (PM)-induced health effects are believed to involve inflammation and oxidative stress. Increased intake of omega-<em>3</em> polyunsaturated fatty acids (n-<em>3</em> PUFA) appears to have anti-inflammatory effects.

OBJECTIVE

As part of a trial to evaluate whether n-<em>3</em> PUFA supplementation could protect against the cardiac alterations linked to PM exposure, we measured biomarkers of response to oxidative stimuli [copper/zinc (Cu/Zn) superoxide dismutase (SOD) activity, lipoperoxidation (LPO) products, and reduced glutathione (GSH)] and evaluated the impact of supplementation on plasma levels.

METHODS

We recruited residents from a nursing home in Mexico City chronically exposed to PM < or = 2.5 microm in aerodynamic diameter (PM(2.5)) and followed them from 26 September 2001 to 10 April 2002. We randomly assigned subjects in a double-blind fashion to receive either fish oil (n-<em>3</em> PUFA) or soy oil. We measured PM(2.5) levels indoors at the nursing home, and measured Cu/Zn SOD activity, LPO products, and GSH at different times during presupplementation and supplementation phases.

RESULTS

Supplementation with either fish or soy oil was related to an increase of Cu/Zn SOD activity and an increase in GSH plasma levels, whereas exposure to indoor PM(2.5) levels was related to a decrease in Cu/Zn SOD activity and GSH plasma levels.

CONCLUSIONS

Supplementation with n-<em>3</em> PUFA appeared to modulate the adverse effects of PM(2.5) on these biomarkers, particularly in the fish oil group. Supplementation with n-<em>3</em> PUFA could modulate oxidative response to PM(2.5) exposure.

UV-induced apoptosis in keratinocytes is a highly complex process in which various molecular pathways are involved. These include the extrinsic pathway via triggering of death receptors and the intrinsic pathway via DNA damage and reactive oxygen species (ROS) formation. In this study we investigated the effect of catalase and CuZn-superoxide dismutase (<em>SOD</em>) overexpression on apoptosis induced by UVB exposure at room temperature or 4 degrees C on normal human keratinocytes. Irradiation at low temperature reduced UV-induced apoptosis by 40% in normal keratinocytes independently of any change in p5<em>3</em> and with a decrease in caspase-8 activation. Catalase overexpression decreased apoptosis by 40% with a reduction of caspase-9 activation accompanied by a decrease in p5<em>3</em>. Keeping cells at low temperature and catalase overexpression had additive effects. CuZn-<em>SOD</em> overexpression had no significant effect on UVB-induced apoptosis. UVB induced an increase in ROS levels at two distinct stages: immediately following irradiation and around <em>3</em> h after irradiation. Catalase overexpression inhibited only the late increase in ROS levels. We conclude that catalase overexpression has a protective role against UVB irradiation by preventing DNA damage mediated by the late ROS increase.

OBJECTIVE

We have demonstrated that copper-zinc superoxide dismutase (CuZn-SOD), a cytosolic isoenzyme of SODs, has a protective role in the pathogenesis of superoxide radical-mediated brain injury. Using mice bearing a disruption of the CuZn-SOD gene (Sod1), the present study was designed to clarify the role of superoxide anion in the pathogenesis of selective vulnerability after transient global ischemia.

METHODS

Sod1 knockout homozygous mutant mice (Sod1 -/-) with a complete absence of endogenous CuZn-SOD activity, heterozygous mutant mice (Sod1 +/-) with a 50% decrease in the activity, and littermate wild-type mice (male, 35 to 45 g) were subjected to global ischemia. Since the plasticity of the posterior communicating artery (PcomA) has been reported to influence the outcome of hippocampal injury, we assessed the relation between the plasticity of PcomAs and the decrease of regional cerebral blood flow in global ischemia.

RESULTS

The fluorescence intensity of hydroethidine oxidation, a measurement of ethidium fluorescence for superoxide radicals, was increased in mutant mice 1 day after both 5 and 10 minutes of global ischemia, compared with wild-type mice. Hippocampal injury in the PcomA hypoplastic brains showed significant exacerbation in mutant mice compared with wild-type littermates 3 days after 5 minutes of global ischemia, although a marked difference was not observed at 1 day.

CONCLUSIONS

These data suggest that superoxide radicals play an important role in the pathogenesis of delayed injury in the vulnerable hippocampal CA1 subregion after transient global ischemia.

Oxidative stress plays an important role in the pathogenesis of Alzheimer's disease. To determine which mechanisms cause the origin of oxidative damage, we analyzed enzymatic antioxidant defense (Cu/Zn-superoxide dismutase Cu/Zn-<em>SOD</em>, glutathione peroxidase GPx and glutathione reductase GR) and lipid peroxidation products malondialdehyde MDA and 4-hydroxynonenal HNE in two different APP transgenic mouse models at <em>3</em>-4 and 12-15 months of age. No changes in any parameter were observed in brains from PDGF-APP695(SDL) mice, which have low levels of Abeta and no plaque load. In contrast, Thy1-APP751(SL) mice show high Abeta accumulation with aging and plaques from an age of 6 months. In brains of these mice, HNE levels were increased at <em>3</em> months (female transgenic mice) and at 12 months (both gender), that is, before and after plaque deposition, and the activity of Cu/Zn-<em>SOD</em> was reduced. Interestingly, beta-amyloidogenic cleavage of APP was increased in female Thy1-APP751(SL) mice, which also showed increased HNE levels with simultaneously reduced Cu/Zn-<em>SOD</em> activity earlier than male Thy1-APP751(SL) mice. Our results demonstrate that impaired Cu/Zn-<em>SOD</em> activity contributes to oxidative damage in Thy1-APP751(SL) transgenic mice, and these findings are closely linked to increased beta-amyloidogenic cleavage of APP.

Extended exposure (100s) of the macaque retina to blue light (400-500nm) produces a photochemical type or types of lesion. The basic mechanisms responsible for such photic damage are unknown but the toxic combination of light and oxygen leading to the free radicals O-.2, H2O2, OH., and O2(1 delta) have been suggested as a possible source of the phototoxicity. To test this hypothesis, the radiant exposure (J. cm-2) to short wavelength light (4<em>3</em>5-445nm) required for minimal damage in the macaque retina is under investigation as a function of oxygenation and after administration of substances known to either inhibit/scavenge radicals or act as anti-inflammatory/anti-oxidant agents. Substances under study include beta-carotene, steroids, catalase and <em>SOD</em>. Here we report radiant exposure in J.cm-2 needed to produce a minimal lesion vs oxygenation as measured by partial pressure of O2 in arterial blood (Po2). There is a sharp drop in the radiant exposure threshold with increase in the partial pressure of O2 in arterial blood, e.g. <em>3</em>0 J.cm-2 at 75 torr to 10 J.cm-2 at 271 torr, a factor of <em>3</em>. Methylprednisolone injected intravenously one hour before exposure (125 mg) has been shown to raise the threshold for retinal damage in two macaques by a factor of approximately 2. Another animal fed beta-carotene (7.5 mg daily) over a period of <em>3</em> months has been exposed to blue light at several levels of oxygenation. The results suggest a protective effect.

How cells ensure correct metallation of a given protein and whether a degree of promiscuity in metal binding has evolved are largely unanswered questions. In a classic case, iron- and manganese-dependent superoxide dismutases (<em>SODs</em>) catalyze the disproportionation of superoxide using highly similar protein scaffolds and nearly identical active sites. However, most of these enzymes are active with only one metal, although both metals can bind in vitro and in vivo. Iron(ii) and manganese(ii) bind weakly to most proteins and possess similar coordination preferences. Their distinct redox properties suggest that they are unlikely to be interchangeable in biological systems except when they function in Lewis acid catalytic roles, yet recent work suggests this is not always the case. This review summarizes the diversity of ways in which iron and manganese are substituted in similar or identical protein frameworks. As models, we discuss (1) enzymes, such as epimerases, thought to use Fe(II) as a Lewis acid under normal growth conditions but which switch to Mn(II) under oxidative stress; (2) extradiol dioxygenases, which have been found to use both Fe(II) and Mn(II), the redox role of which in catalysis remains to be elucidated; (<em>3</em>) <em>SODs</em>, which use redox chemistry and are generally metal-specific; and (4) the class I ribonucleotide reductases (RNRs), which have evolved unique biosynthetic pathways to control metallation. The primary focus is the class Ib RNRs, which can catalyze formation of a stable radical on a tyrosine residue in their β2 subunits using either a di-iron or a recently characterized dimanganese cofactor. The physiological roles of enzymes that can switch between iron and manganese cofactors are discussed, as are insights obtained from the studies of many groups regarding iron and manganese homeostasis and the divergent and convergent strategies organisms use for control of protein metallation. We propose that, in many of the systems discussed, "discrimination" between metals is not performed by the protein itself, but it is instead determined by the environment in which the protein is expressed.

Reactive oxygen species (ROS), produced by cellular constituents of the arterial wall, provide a signaling mechanism involved in vascular remodeling. Because adventitial fibroblasts are actively involved in coronary remodeling, we examined whether the changes in the redox state affect their phenotypic characteristics. To this end, superoxide anion production and NAD(P)H oxidase activity were measured in porcine coronary arteries in vivo, and the effect of ROS generation on adventitial fibroblast proliferation was examined in vitro. Superoxide production (<em>SOD</em>- and Tiron-inhibitable nitro blue tetrazolium [NBT] reduction) increased significantly within 24 hours after balloon-induced injury, with the product of NBT reduction present predominantly in adventitial fibroblasts. These changes were NAD(P)H oxidase-dependent, because diphenyleneiodonium (DPI) abolished superoxide generation (P<0.001). Furthermore, the injury-induced superoxide production was associated with augmented NAD(P)H oxidase activity and upregulation of p47(phox) and p67(phox) in adventitial fibroblasts (immunohistochemistry). Serum stimulation of isolated adventitial fibroblasts produced time-dependent increases in ROS production (peak <em>3</em> to 6 hours). The inhibition of ROS generation with NAD(P)H oxidase inhibitor (DPI) or the removal of ROS with antioxidants (Tiron, catalase) abrogated proliferation of adventitial fibroblasts. These results indicate that vascular NAD(P)H oxidase plays a central role in the upregulation of oxidative stress after coronary injury, providing pivotal growth signals for coronary fibroblasts.

Oxidative stress and zinc release are both known to contribute to neuronal death after hypoglycemia; however, the cause-effect relationships between these events are not established. Here we found, using a rat model of profound hypoglycemia, that the neuronal zinc release and translocation that occur immediately after hypoglycemia are prevented by the nitric oxide synthase inhibitor 7-nitroindazole but not by overexpression of superoxide dismutase-1 (<em>SOD</em>-1). However, overexpression of <em>SOD</em>-1 prevented activation of poly(ADP-ribose) polymerase-1 (PARP-1) and neuronal death, suggesting that zinc release is upstream of superoxide production. Accordingly, zinc-induced superoxide production was blocked in neuronal cultures by the NADPH oxidase inhibitor apocynin and by genetic deficiency in the p47(phox) subunit of NADPH oxidase. A key role for the vesicular zinc pool in this process was suggested by reduced superoxide formation and neuronal death in mice deficient in zinc transporter <em>3</em>. Together, these findings suggest a series of events in which nitric oxide production triggers vesicular zinc release, which in turn activates NADPH oxidase and PARP-1. This sequence may also occur in other central nervous system disorders in which zinc, nitric oxide, and oxidative stress have been linked.

BACKGROUND

Copper is an essential element in various metabolisms. The investigation was carried out to evaluate acute gastroprotective effects of the Copper (II) complex against ethanol-induced superficial hemorrhagic mucosal lesions in rats.

RESULTS

Rats were divided into 7 groups. Groups 1 and 2 were orally administered with Tween 20 (10% v/v). Group <em>3</em> was orally administered with 20 mg/kg omeprazole (10% Tween 20). Groups 4-7 received 10, 20, 40, and 80 mg/kg of the complex (10% Tween 20), respectively. Tween 20 (10% v/v) was given orally to group 1 and absolute ethanol was given orally to groups 2-7, respectively. Rats were sacrificed after 1 h. Group 2 exhibited severe superficial hemorrhagic mucosal lesions. Gastric wall mucus was significantly preserved by the pre-treatment complex. The results showed a significant increase in glutathione (GSH), superoxide dismutase (<em>SOD</em>), nitric oxide (NO), and Prostaglandin E2 (PGE(2)) activities and a decrease in malondialdehyde (MDA) level. Histology showed marked reduction of hemorrhagic mucosal lesions in groups 4-7. Immunohistochemical staining showed up-regulation of Hsp70 and down-regulation of Bax proteins. PAS staining of groups 4-7 showed intense stain uptake of gastric mucosa. The acute toxicity revealed the non-toxic nature of the compound.

CONCLUSIONS

The gastroprotective effect of the Copper (II) complex may possibly be due to preservation of gastric wall mucus; increase in PGE(2) synthesis; GSH, SOD, and NO up-regulation of Hsp70 protein; decrease in MDA level; and down-regulation of Bax protein.

Drug-induced acute liver failure (ALF) is a devastating and often fatal disease mainly caused by poisoning by acetaminophen (APAP). The toxic metabolite, N-acetyl-p-benzoquinone-imine (NAPQI), that leads to gluthatione depletion has been suspected to be the main effector of hepatocyte apoptosis during APAP-induced ALF. We have investigated whether reactive oxygen species (ROS) also play a role in APAP-induced ALF, and whether manganese III tetrakis (5,10,15,20 benzoic acid) (MnTBAP), a mimic of superoxide dismutase (<em>SOD</em>) with catalase-like activity, can treat the disease in mice. The effects of MnTBAP were tested on APAP-intoxicated mice and on isolated hepatocytes incubated with APAP. MnTBAP preventively and curatively administered significantly improved survival times, and dramatically reduced serum transaminase activity levels and parenchymal lesions in APAP-intoxicated mice. Whereas pretreatment with N-acetyl-L-cysteine (NAC) prevented ALF in a dose-dependent manner, the molecule was ineffective when curatively administered. The significant increase in glutathione peroxidase (Gpx) activity following APAP administration, and the beneficial effects of MnTBAP suggested that ROS were produced during APAP-induced ALF. A direct evidence of ROS generation was provided by flow cytometry of isolated hepatocytes incubated with APAP. In vitro, ROS production was associated with mitochondrial damage characterized by the collapse of transmembrane potential and the loss of cardiolipin content. In livers of intoxicated mice, ALF was associated with cytochrome c release that led to the activation of caspases-9 and -<em>3</em>. The capacity of MnTBAP to abrogate all those alterations suggests that ROS play a role in APAP-induced apoptosis of hepatocytes, and explains the beneficial effects of MnTBAP, which could be of interest in APAP-induced ALF in humans.

OBJECTIVE

We sought to develop a therapeutic agent that would permit prolongation of survival in rats subjected to lethal hemorrhagic shock (HS), even in the absence of resuscitation with asanguinous fluids or blood.

RESULTS

We synthesized a series of compounds that consist of the electron scavenger and superoxide dismutase mimic, 4-amino-2,2,6,6-tetramethylpiperidine-N-oxyl (4-NH2-TEMPO), conjugated to fragments and analogs of the membrane-active cyclopeptide antibiotic, gramicidin S. Using an in vivo assay, wherein isolated intestinal segments were loaded inside the lumen with various test compounds, we studied these compounds for their ability to prevent ileal mucosal barrier dysfunction induced by subjecting rats to profound HS for 2 hours. The most active compound in this assay, XJB-5-1<em>3</em>1, ameliorated peroxidation of the mitochondrial phospholipid, cardiolipin, in ileal mucosal samples from rats subjected to HS. XJB-5-1<em>3</em>1 also ameliorated HS-induced activation of the pro-apoptotic enzymes, caspases <em>3</em> and 7, in ileal mucosa. Intravenous treatment with XJB-5-1<em>3</em>1 (2 micromol/kg) significantly prolonged the survival of rats subjected to profound blood loss (<em>3</em><em>3</em>.5 mL/kg) despite administration of only a minimal volume of crystalloid solution (2.8 mL/kg) and the absence of blood transfusion.

CONCLUSIONS

These data support the view that mitochondrially targeted electron acceptors and SOD mimics are potentially valuable therapeutics for the treatment of serious acute conditions, such as HS, which are associated with marked tissue ischemia.

OBJECTIVE

Ischaemic preconditioning may be mediated by oxygen free radicals generated during preconditioning. Conflicting results have been reported regarding the effect of superoxide dismutase (SOD) in attenuating the cardioprotective effect of preconditioning. The aim of the study was to reconcile this conflict by examining the effect of three different oxyradical scavengers on the infarct size limiting effect of preconditioning.

METHODS

Anaesthetised open chest rabbits were subjected to 30 min coronary occlusion and 48 h reperfusion. In the preconditioning groups, rabbits were subjected to a single 5 min occlusion and 5 min reperfusion before 30 min sustained ischaemia. In these groups, the oxyradical scavengers SOD (15,000 U.kg-1), N-2-mercaptopropionyl glycine (MPG, 20 mg.kg-1), and dimethylthiourea (DMTU, 500 mg.kg-1), or placebo saline, were infused before and during preconditioning. In the non-preconditioning groups, these agents were given in the same time frame before 30 min of ischaemia. After 2 d reperfusion, infarct size was measured microscopically.

RESULTS

In the saline treated controls, preconditioning markedly limited microscopical infarct size (percent of area at risk): 13(SEM 3)% (n = 9) v 49(9)% (n = 8), p < 0.05. Treatment of the preconditioning groups with SOD or MPG attenuated this cardioprotection [infarct size 31(5)% (n = 11) and 42(8)% (n = 11), respectively, p < 0.05 v the saline treated preconditioning group], but treatment with DMTU did not [infarct size 23(6)% (n = 11), p = NS v the saline treated preconditioning group]. In the non-preconditioning groups, none of the treatments modified infarct size: 50(9)% (n = 7), 56(5)% (n = 8), and 61(6)%, (n = 8), respectively, p = NS v saline treated control.

CONCLUSIONS

Cardioprotection by preconditioning is mediated, at least in part, by oxyradicals which are scavenged by SOD or MPG in rabbits.

1. Superoxide dismutase (<em>SOD</em>, 60 u ml-1) or ferricytochrome c (70 microM) significantly inhibited thrombin-stimulated platelet adhesion to gelatin-coated plastic, whereas catalase (1000 u ml-1) or mannitol (1 mM) had no effect. 2. The platelet aggregation induced by low concentrations of thrombin (causing less than 45% maximal change in light transmission) was inhibited by <em>SOD</em>. Catalase or mannitol had no effect on platelet aggregation. <em>3</em>. Pyrogallol (an O2- generator) enhanced both platelet adhesion to gelatin-coated plastic and platelet aggregation induced by thrombin; this enhancement was neutralized by <em>SOD</em>. 4. These results indicate that O2- increase both platelet adhesion and aggregation, whereas other free radicals such as hydrogen peroxide or hydroxyl radicals are not involved.

The roles of oxidative stress and renal superoxide dismutase (<em>SOD</em>) levels and their association with renal damage were studied in Dahl salt-sensitive (S) and salt-resistant (R)/Rapp strain rats during changes in Na intake. After <em>3</em> wk of a high (8%)-Na diet in S rats, renal medullary Cu/Zn <em>SOD</em> was 56% lower and Mn <em>SOD</em> was 81% lower than in R high Na-fed rats. After 1, 2, and <em>3</em> wk of high Na, urinary excretion of F(2)-isoprostanes, an index of oxidative stress, was significantly greater in S rats compared with R rats. Plasma F(2)-isoprostane concentration increased in the 2-wk S high Na-fed group. After <em>3</em> wk, renal cortical and medullary superoxide production was significantly increased in Dahl S rats on high Na intake, and urinary protein excretion, an index of renal damage, was 27<em>3</em> +/- <em>3</em>2 mg/d in S high Na-fed rats and <em>3</em>5 +/- 4 mg/d in R high Na-fed rats (P < 0.05). In conclusion, salt-sensitive hypertension in the S rat is accompanied by marked decreases in renal medullary <em>SOD</em> and greater renal oxidative stress and renal damage than in R rats.

BACKGROUND

Superoxide dismutase (<em>SOD</em>) <em>3</em> inhibits oxidative fragmentation of lung matrix components collagen I, hyaluronan, and heparan sulfate. Inherited change in <em>SOD</em><em>3</em> expression or function could affect lung matrix homeostasis and influence pulmonary function.

OBJECTIVE

To identify novel <em>SOD</em><em>3</em> polymorphisms that are associated with lung function or chronic obstructive pulmonary disease (COPD).

METHODS

Resequencing of 182 individuals identified two novel polymorphisms, E1 (rs8192287) and I1 (rs8192288), in a conserved region of the <em>SOD</em><em>3</em> gene of potential relationship to lung function. We next genotyped 9,09<em>3</em> individuals from the Copenhagen City Heart Study for the polymorphisms and recorded spirometry, and admissions and deaths due to COPD during 26-year follow-up. Finally, we validated our findings in a cross-sectional analysis of <em>3</em>5,6<em>3</em>5 individuals from the Copenhagen General Population Study.

RESULTS

Genotyping the Copenhagen City Heart Study identified <em>3</em>5 E1/I1 homozygotes, 1,050 heterozygotes, and 8,008 noncarriers (Hardy-Weinberg equilibrium: P = 0.9<em>3</em>). Using quadruple lung function measurements, we found that E1/I1 homozygotes had 7% lower FVC % predicted (P = 0.006) and 4% lower FEV(1) % predicted (P = 0.12) compared with noncarriers. In the Copenhagen General Population Study, E1/I1 homozygotes also had lower FVC % predicted than noncarriers (P = 0.0<em>3</em>), confirming an association between E1/I1 genotype and reduced lung function. E1/I1 homozygotes had adjusted hazard ratios for COPD hospitalization and COPD mortality of 2.5 (95% confidence interval, 1.0-5.9) and <em>3</em>.7 (95% confidence interval, 0.9-15), respectively; the results were independent of influence from the R21<em>3</em>G allele of the <em>SOD</em><em>3</em> gene.

CONCLUSIONS

We identified two novel polymorphisms in a conserved region of the <em>SOD</em><em>3</em> gene and show that individuals that are homozygous for these polymorphisms have reduced FVC % predicted in two large, population-based studies.

Endothelial cells produce oxygen radicals spontaneously and this process is augmented by hypoxia/reoxygenation. Cu/Zn superoxide dismutase (<em>SOD</em>-1) is an important enzyme in cellular oxygen metabolism. To determine whether alterations in <em>SOD</em>-1 activity affect angiogenesis we used transgenic <em>SOD</em>-1 (Tg-<em>SOD</em>) mice with elevated level of <em>SOD</em>-1. Angiogenesis induced subcutaneously by bFGF in Tg-<em>SOD</em> mice was <em>3</em>-fold higher than in control non-transgenic (ntg) mice. Oral administration of disulfiram (DSF), an inhibitor of <em>SOD</em>-1, inhibited angiogenesis in Tg-<em>SOD</em> mice as well as in CD1 nude mice. Effects of DSF on cultured cells were also tested. Application of DSF to cultured bovine capillary endothelial (BCE) cells caused inhibition of DNA synthesis and induction of apoptosis. These effects were prevented by addition of antioxidants, further indicating involvement of reactive oxygen species. DSF also reduced the level of glutathione and the production of H(2)O(2) in BCE cells. Moreover, PC12-<em>SOD</em> cells with elevated <em>SOD</em>-1 were less sensitive to DSF treatment then control cells. These data indicate that the effects of DSF are mediated by inhibition of <em>SOD</em>-1 activity. Tumor development is known to largely depend on angiogenesis. We found that oral administration of DSF to mice caused significant inhibition of C6 glioma tumor development and marked reduction (by 10-19-fold) in metastatic growth of Lewis lung carcinoma. The data suggest a role for <em>SOD</em>-1 in angiogenesis, establish DSF as a potential inhibitor of angiogenesis and raise the possibility that attenuating <em>SOD</em>-1 activity may be important in treatment of angiogenesis-dependent pathologies.

This study was conducted to investigate serum amino acids profile in dextran sulfate sodium (DSS)-induced colitis, and impacts of graded dose of arginine or glutamine supplementation on the colitis. Using DSS-induced colitis model, which is similar to human ulcerative colitis, we determined serum profile of amino acids at day <em>3</em>, 7, 10 and 12 (5 days post DSS treatment). Meanwhile, effects of graded dose of arginine (0.4%, 0.8%, and 1.5%) or glutamine (0.5%, 1.0% and 2.0%) supplementation on clinical parameters, serum amino acids, colonic tight junction proteins, colonic anti-oxidative indicators [catalase, total superoxide dismutase (T-<em>SOD</em>), glutathione peroxidase (GSH-Px)], colonic pro-inflammatory cytokines [interleukin-1 beta (IL-1β), IL-6, IL-17 and tumor necrosis factor alpha (TNF-α)] in DSS-induced colitis were fully analyzed at day 7 and 12. Additionally, the activation of signal transduction pathways, including nuclear factor kappa B (NF-κB), mitogen-activated protein kinases (MAPK), phosphoinositide-<em>3</em>-kinases (PI<em>3</em>K)/PI<em>3</em>K-protein kinase B (Akt), and myosin light chain kinase (MLCK)-myosin light chain (MLC20), were analyzed using immunoblotting. Serum amino acids analysis showed that DSS treatment changed the serum contents of amino acids, such as Trp, Glu, and Gln (P<0.05). Dietary arginine or glutamine supplementation had significant (P<0.05) influence on the clinical and biochemical parameters (T-<em>SOD</em>, IL-17 and TNF-α) in colitis model. These results were associated with colonic NF-κB, PI<em>3</em>K-Akt and MLCK signaling pathways. In conclusion, arginine or glutamine could be a potential therapy for intestinal inflammatory diseases.