Cordycepin, (<em>3</em>'-deoxyadenosine), a bioactive compound of Cordyceps militaris, has been shown to exhibit many pharmacological actions, such as anti-inflammatory, antioxidative and anticancer activities. Little is known about the neuroprotective action of cordycepin as well as its molecular mechanisms. In this study, cordycepin was investigated for its neuroprotective potential in mice with ischemia following 15 min of the bilateral common carotid artery occlusion and 4h of reperfusion. The effect of cordycepin was also studied in mice brain slices treated with oxygen-glucose deprivation (OGD) injury. Our results showed that cordycepin was able to prevent postischemic neuronal degeneration and brain slice injury. Excitatory amino acids such as glutamate and aspartate in brain homogenized supernatant, which were increased in ischemia/reperfusion group, were detected by high performance liquid chromatography (HPLC). The results showed that cordycepin was able to decrease the extracellular level of glutamate and aspartate significantly. Moreover, cordycepin was able to increase the activity of superoxide dismutase (<em>SOD</em>) and decrease the level of malondialdehyde (MDA), ameliorating the extent of oxidation. Furthermore, matrix metalloproteinase-<em>3</em>(MMP-<em>3</em>), a key enzyme involved in inflammatory reactions, was markedly increased after ischemia reperfusion, whereas cordycepin was able to inhibit its expression obviously. In conclusion, our in vivo and in vitro study showed that cordycepin was able to exert a potent neuroprotective function after cerebral ischemia/reperfusion.

Oxidative stress is implicated as an important factor in the development of Alzheimer's disease (AD). In the present study, we have investigated the effects of edaravone (9mg/kg, <em>3</em>-methyl-1-phenyl-2-pyrazolin-5-one), a free radical scavenger, in a streptozotocin (STZ-<em>3</em>mg/kg) induced rat model of sporadic AD (sAD). Treatment with edaravone significantly improved STZ-induced cognitive damage as evaluated in Morris water maze and step-down tests and markedly restored changes in malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE) adducts, hydroxyl radical (OH), hydrogen peroxide (H2O2), total superoxide dismutase (T-<em>SOD</em>), reduced glutathione (GSH), glutathione peroxidase (GPx) and protein carbonyl (PC) levels. In addition, histomorphological observations confirmed the protective effect of edaravone on neuronal degeneration. Moreover, hyperphosphorylation of tau resulting from intracerebroventricular streptozotocin (ICV-STZ) injection was decreased by the administration of edaravone. These results provide experimental evidence demonstrating preventive effects of edaravone on cognitive dysfunction, oxidative stress and hyperphosphorylation of tau in ICV-STZ rats. Since edaravone has been used for treatment of patients with stroke, it represents a safe and established therapeutic intervention that has the potential for a novel application in the treatment of age-related neurodegenerative disorders associated with cognitive decline, such as AD.

Strenuous exercise is detrimental to athletes because of the overproduction of reactive oxygen species. Melatonin, a classic antioxidant, has been shown to exhibit beneficial effects regarding intense exercise and tissue repair. In this study, we evaluated the onset and resolution of inflammation in melatonin-treated and nontreated rats subjected to a strenuous exercise session. We also analyzed the formation of thiobarbituric acid reactive substances (TBARS) and the activities of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (<em>SOD</em>). Control and treated rats were subjected to exhaustive exercise after a period of 10 days of melatonin treatment (20 mg/dL). Plasma and muscle levels of tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), cytokine-induced neutrophil chemoattractant-2-alpha/beta (CINC-2α/β), l-selectin, macrophage inflammatory protein-<em>3</em>-alpha (MIP-<em>3</em>α), and vascular endothelial growth factor (VEGF) were measured prior to, immediately after, and 2 hr after exercise. Our data revealed decreases in the muscle concentrations of IL-1β (<em>3</em>5%), TNF-α (1<em>3</em>%), IL-6 (48%), and TBARS (40%) in the melatonin-treated group compared with the control group. We also observed decreases in the plasma concentrations of IL-1β (17%) in the melatonin-treated group. VEGF-α concentrations and <em>SOD</em> activity increased by 179% and 22%, respectively, in the melatonin-treated group compared with the control group. We concluded that muscle inflammation and oxidative stress resulting from exhaustive exercise were less severe in the muscles of melatonin-treated animals than in the muscles of control animals. Thus, melatonin treatment may reverse exercise-induced skeletal muscle inflammation and stimulate growth factor synthesis.

OBJECTIVE

The extracellular superoxide dismutase <em>3</em> (<em>SOD</em><em>3</em>) is an isoform of <em>SOD</em>. Extensive studies have been focused on role of <em>SOD</em><em>3</em> as an antioxidant. However, the role of <em>SOD</em><em>3</em> in the immune responses that contribute to the inhibition of allergic lung inflammation has not been investigated.

RESULTS

Here, we report for the first time that <em>SOD</em><em>3</em> specifically inhibits dendritic cell maturation. Subsequently, <em>SOD</em><em>3</em> controls T cell activation and proliferation, and T helper 2 (Th2) and Th17 cell differentiation. As a consequence, the administration of <em>SOD</em><em>3</em> into mice alleviated Th2-cell-mediated ovalbumin (OVA)-induced allergic asthma. In addition, we demonstrated that <em>SOD</em><em>3</em> inhibits OVA-induced airway extracellular remodeling and Th2 cell trafficking. Through mass spectrometry analysis, the proteins interacting with <em>SOD</em><em>3</em> in the lung of asthma were identified. And it was revealed that signaling molecules, such as transforming growth factor (TGF) and epidermal growth factor (EGF) receptor, adhesion and adaptor molecules, kinases, phosphatases, NADPH oxidase, and apoptosis-related factor, were involved, which were altered by administration of <em>SOD</em><em>3</em>. Relatively severe asthma was observed in <em>SOD</em><em>3</em> KO mice and was ameliorated by both the administration of <em>SOD</em><em>3</em> and adoptive transfer of <em>SOD</em><em>3</em>-sufficient CD4 T cells. Moreover, the expression of endogenous <em>SOD</em><em>3</em> in the lung peaked early in OVA challenge and gradually decreased upon disease progression, while both <em>SOD</em>1 and <em>SOD</em>2 expression changed relatively little.

CONCLUSIONS

Thus, our data suggest that <em>SOD</em><em>3</em> is required to maintain lung homeostasis and acts, at least in part, as a controller of signaling and a decision maker to determine the progression of allergic lung disease.

We have described that the progression of thoracic aortic aneurysm in Marfan syndrome is accompanied with aortic vascular dysfunction. In the present study, we hypothesized that the impaired contractile function and endothelial-dependent relaxation could be resulted from oxidative stress in the thoracic aorta. Adrenergic contraction and cholinergic relaxation of thoracic aortae from mice (n=40; age=<em>3</em>, 6, 9 months) heterozygous for FBN1 allele (Fbn1(C10<em>3</em>9G/+)), a well-defined model of Marfan syndrome, were compared with those from control (n=40). The aortic 8-isoprostane level, an oxidative stress marker, was <em>3</em>2-50% greater in the Marfan group than in the control. Pre-incubation with superoxide dismutase (<em>SOD</em>) improved the phenylephrine-induced contraction and the sensitivity to acetylcholine in Marfan aortae, but not in controls. The phenylephrine-contraction in Marfan aortae was potentiated by 1400 W, an inducible nitric oxide synthase (iNOS) inhibitor, and allopurinol, a xanthine oxidase inhibitor. Acetylcholine-induced relaxation was restored by apocynin, an inhibitor of NAD(P)H oxidase. Protein expression of <em>SOD</em>-1 and <em>SOD</em>-2 was decreased in Marfan aortae, whereas that of xanthine oxidase, iNOS, and the enzymatic subunits of NAD(P)H oxidase was increased. The vasomotor dysfunction in Marfan thoracic aortae could be associated with accumulation of oxidative stress due to unbalanced protein expression of superoxide-producing and superoxide-eliminating enzymes.

The aim of this study was to investigate the synergistic hepatoprotective effect of lignans from Fructus Schisandrae chinensis (LFS) with Astragalus polysaccharides (APS) on chronic liver injury in male Sprague-Dawley rats. Subcutaneous injection of 10% CCl(4) twice a week for <em>3</em> months resulted in significantly (p<0.001) elevated serum alanine aminotransferase (ALT), asparate aminotransferase (AST), alkaline phosphatase (ALP) activities compared to controls. In the liver, significantly elevated levels (p<0.001) of malondialdehyde (MDA), lowered levels of reduced glutathione (GSH) (p<0.05) and catalase (CAT) (p<0.001), superoxide dismutase (<em>SOD</em>) (p<0.01)were observed following CCl(4) administration. 'LFS+ASP' treatment of rats at doses of 'LFS (45mg/kg)+APS (150mg/kg)' and 'LFS (1<em>3</em>5mg/kg)+APS (450mg/kg)' displayed hepatoprotective and antioxidative effects than the administration of either LFS or APS, as evident by lower (p<0.005 or 0.001) levels of serum ALT, AST, ALP and hepatic MDA (p<0.001) concentration, as well as higher <em>SOD</em> (p<0.05 or 0.005), CAT activities(p<0.01 or 0.005), GSH concentration (p<0.05 or 0.005) compared to the toxin treated group. Histopathological examinations revealed severe fatty degeneration in the toxin group, and mild damage in groups treated with 'LFS+APS' were observed. The coefficients drug interaction (CDI) between each individual drug and their combination (at the same dose of their single treatment) of these foregoing parameters were all less than 1, indicating that LFS and APS display hepatoprotective and antioxidant properties and act in a synergistic manner in CCl(4) induced liver injury in rats.

OBJECTIVE

Topotecan, a semisynthetic water-soluble derivative of camptothecin exerts its cytotoxic effect by inhibiting topoisomerase I and causes double-strand DNA breaks which inhibit DNA function and ultimately lead to cell death. In previous studies it was shown that camptothecin causes ROS formation. The aim of this study was to investigate if Topotecan like camptotecin causes oxidative stress in MCF-7 human breast cancer cell line. Determining the oxidant effect of Topotecan may elucidate a possible alternative mechanism for its cytotoxicity.

METHODS

MCF-7 cells were cultured and exposed to Topotecan for 24 h at <em>3</em>7 degrees C. The viability of the cells (% of control) was measured using the colorimetric <em>3</em>-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Lipid peroxidation (TBARS), protein oxidation (carbonyl content), sulfhydryl, glutathione (GSH) levels, superoxide dismutase (<em>SOD</em>), catalase (CAT) and glutathione peroxidase (GPx) activities were determined in MCF-7 cells with and without Topotecan incubation.

RESULTS

We found the IC(50) concentration of Topotecan as 0.218 microM in MCF-7 cells. This concentration of Topotecan was used in the incubations of the cells. Our data indicated increased oxidative status, as revealed by increased lipid peroxidation and protein oxidation, and decreased GSH and sulfhydryl levels in MCF-7 cells exposed to Topotecan compared to control cells. In contrast, there was a slight increase in SOD and a significant increase in GPx and catalase activity in MCF-7 cells incubated with Topotecan compared to the control.

CONCLUSIONS

These results support our hypothesis that Topotecan increases oxidative stress in MCF-7 cells.

OBJECTIVE

Oxidative stress is related to the carcinogenic pathway of reflux esophagitis to Barrett's metaplasia to esophageal adenocarcinoma (EAC). Recent studies have shown that a decreased manganese superoxide dismutase (MnSOD) level is associated with the increased incidences of Barrett's esophagus (BE) and EAC. The aim of this study was to investigate MnSOD supplementation as a chemopreventive agent to prevent oxidative injury and subsequent BE and EAC formation.

METHODS

Our esophagoduodenal anastomotic (EDA) model was done on rats according to our established procedure and treated with Mn(III)tetrakis(4-benzoic acid) porphyrin (MnTBAP; 10 mg/kg, i.p. every <em>3</em> days). Histologic changes were determined after the EDA model at 1, <em>3</em>, and 6 months. Lipid peroxidation and 8-hydroxy-deoxyguanosine for DNA oxidative damage were determined by thiobarbituric acid-reactive substance assay and immunohistochemical staining. Enzymatic activities of MnSOD and Cu/ZnSOD were evaluated, and the rate of proliferation was determined by proliferating cell nuclear antigen staining.

RESULTS

Severe esophagitis was seen in 100% of the EDA rats, and morphologic transformation within the esophageal epithelium was observed with intestinal metaplasia (40% of animals) and cancer (40% of animals) identified after <em>3</em> months. Decreased oxidative damage, along with the decreased degree of esophagitis and incidence of BE (20%) and EAC (0%), was found in MnTBAP-treated EDA rats comparing with the saline-treated EDA control. Decreased proliferation (46%) and increased SOD enzymatic activities (25%) were also found in the EDA rats treated with MnTBAP.

CONCLUSIONS

MnTBAP protected rat esophageal epithelium from oxidative injury induced by EDA, and it could prevent the transformation of esophageal epithelial cell to BE to EAC by preservation of antioxidants.

Cis-unsaturated fatty acids of both the n-6 and n-<em>3</em> series have been shown to be cytotoxic to a variety of tumor cells in vitro. Both gamma-linolenic acid (GLA) and eicosapentaenoic acid (EPA) can also augment the cytotoxicity of anticancer drugs. But, the effect of various cis-unsaturated fatty acids on the survival of tumor cells which are resistant to anticancer drugs has not been studied so far. Docosahexaenoic acid (DHA) and EPA of the n-<em>3</em> series and GLA and dihomo-GLA (DGLA) of the n-6 series were found to be cytotoxic to both vincristine-sensitive (KB-<em>3</em>-1) and resistant (KB-ChR-8-5) human cervical carcinoma (HeLa-variant) cells in vitro. KB-ChR-8-5 was found to be only marginally less sensitive to the cytotoxic actions of all the fatty acids tested except arachidonic acid (AA) compared to KB-<em>3</em>-1. Cyclo-oxygenase inhibitor, indomethacin; lipoxygenase inhibitor, nordihydroguiaretic (NDGA); and calmodulin antagonists, trifluoperazine (TFP) and chlorpromazine (CPZ) were found to be ineffective in blocking the cytotoxic action of GLA, EPA and DHA, the most effective fatty acids, on KB-<em>3</em>-1 cells. This suggests that prostaglandins, leukotrienes and calmodulin do not have any role in the cytotoxic action of GLA, EPA, and DHA. On the other hand, the anti-oxidant, vitamin E, and the superoxide anion quencher, superoxide dismutase (<em>SOD</em>), could completely inhibit the cytotoxic action of GLA, EPA and DHA indicating a role for free radicals and, in particular, the superoxide anion in this process. This was supported further by the observation that GLA, EPA, and DHA can enhance the formation of superoxide anion, hydrogen peroxide, and lipid peroxides in KB-<em>3</em>-1 cells. GLA, EPA, and DHA-induced free radical generation and lipid peroxidation were also inhibited by vitamin E and <em>SOD</em>. These results suggest that GLA, EPA, and DHA are cytotoxic to both vincristine-sensitive and resistant human cervical carcinoma cells and that it is a free radical dependent process.

Peroxynitrite (ONOO(-)/ONOOH) is generally expected to be formed in vivo from the diffusion-controlled reaction between superoxide (O(2)) and nitric oxide ((*)NO). In the present paper we show that under aerobic conditions the nitroxyl anion (NO(-)), released from Angeli's salt (disodium diazen-1-ium-1,2,2-triolate, (-)ON=NO(2)(-)), generated peroxynitrite with a yield of about 65%. Simultaneously, hydroxyl radicals are formed from the nitroxyl anion with a yield of about <em>3</em>% via a minor, peroxynitrite-independent pathway. Further experiments clearly underline that the chemistry of NO(-) in the presence of oxygen is mainly characterized by peroxynitrite and not by HO( small middle dot) radicals. Quantum-chemical calculations predict that peroxynitrite formation should proceed via intermediary formation of (*)NO and O(2), probably by an electron-transfer mechanism. This prediction is supported by the fact that H(2)O(2) is formed during the decay of NO(-) in the presence of superoxide dismutase (Cu(II),Zn-<em>SOD</em>). Since the nitroxyl anion may be released endogenously by a variety of biomolecules, substantial amounts of peroxynitrite might be formed in vivo via NO(-) in addition to the "classical" ( small middle dot)NO + O(2)() pathway.

Coenzyme Q10 is a natural antioxidant and scavenging free radicals. In the present study, we examined antioxidative activities of coenzyme Q10 and possible protective effect of coenzyme Q10 on in vivo and in vitro lipid peroxidation, antioxidant enzymes activity and glomerulosclerosis in alloxan-induced type 1 diabetic rats. Thirty Sprague-Dawley male rats were divided into three groups randomly: group 1 as control, group 2 as diabetic untreatment, and group <em>3</em> as treatments with coenzyme Q10 by 15 mg/kg i.p. daily, respectively. Diabetes was induced in the second and third groups by alloxan injection subcutaneously. After 8 weeks, animals were anaesthetized, liver and kidney were then removed immediately and used fresh or kept frozen until their lipid peroxidation analysis. Blood samples were also collected before killing to measure the lipid peroxidation and antioxidant enzymes activity. Kidney paraffin sections were prepared and stained by periodic acid-Schiff method. Glomerular volume and leukocyte infiltration were estimated by stereological rules and glomerular sclerosis was studied semi-quantitatively. Coenzyme Q10 significantly inhibited leukocyte infiltration, glomerulosclerosis and the levels of malondialdehyde (MDA) serum and kidney content in treated group compared with the diabetic untreated group. Coenzyme Q10 significantly inhibited LDL oxidation in vitro. Coenzyme Q10 significantly increased the serum levels of glutathione (GSH) and serum activity of catalase (CAT) and superoxide dismutase (<em>SOD</em>) in treated group compared with the diabetic untreated group. Coenzyme Q10 alleviates leukocyte infiltration and glomerulosclerosis and exerts beneficial effects on the lipid peroxidation and antioxidant enzymes activity in alloxan-induced type 1 diabetic rats.

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by amyloid β (Aβ) deposits, elevated oxidative stress, and apoptosis of the neurons. Pseudoginsenoside-F11 (PF11), a component of Panax quinquefolium (American ginseng), has been demonstrated to antagonize the learning and memory deficits induced by scopolamine, morphine and methamphetamine in mice. In the present study, we investigated the effect of PF11 on AD-like cognitive impairment both in mice induced by intracerebroventricular injection of Aβ1-42 (410 pmol) and in Tg-APPswe/PS1dE9 (APP/PS1) mice. It was found that oral treatment with PF11 significantly mitigated learning and memory impairment in mice given Aβ1-42-treated mice for 15 days at doses of 1.6 and 8 mg/kg and APP/PS1 for 4 weeks at a dose of 8 mg/kg as measured by the Morris water maze and step-through tests. In APP/PS1 mice, PF11 8 mg/kg significantly inhibited the expressions of β-amyloid precursor protein (APP) and Aβ1-40 in the cortex and hippocampus, restored the activities of superoxide dismutase (<em>SOD</em>) and glutathione peroxidase (GSH-Px) and decreased the production of malondialdehyde (MDA) in the cortex. It also noticeably improved the histopathological changes in the cortex and hippocampus and downregulated the expressions of JNK 2, p5<em>3</em> and cleaved caspase <em>3</em> in the hippocampus. These findings suggested that the inhibitory effect on amyloidogenesis and oxidative stress and some beneficial effects on neuronal functions might contribute to the recognition improvement effect of PF11 in APP/PS1 mice. Cumulatively, the present study indicated that PF11 may serve as a potential therapeutic agent for the treatment of AD.

Aerobic organisms continually face exposure to reactive oxygen species (ROS) and many have evolved sophisticated antioxidant systems to effectively remove them. Any increase in ROS production or weakening in this defense system may ultimately lead to oxidative stress and cellular damage. We investigated whether long-term cold exposure, which is known to lead to an elevation in metabolic rate, increased the activities of the ROS-scavenging enzymes, catalase (CAT), selenium-dependent glutathione peroxidase (GPx), and total superoxide dismutase (Total-<em>SOD</em>) in liver, cardiac muscle, kidney, skeletal muscle (vastus lateralis), and duodenum of short-tailed field voles (Microtus agrestis), born and maintained at either 8 +/- <em>3</em> degrees C or 22 +/- <em>3</em> degrees C. CAT, GPx, and Total-<em>SOD</em> activities were determined at age 61 +/- 1.9 days. An increase in CAT activity in voles maintained at 8 +/- <em>3</em> degrees C was observed in skeletal muscle (71%) and kidney (20%), with both CAT and GPx activities significantly elevated (by 40 and 4<em>3</em>%, respectively) in cardiac muscle, when compared to voles at 22 +/- <em>3</em> degrees C. Total-<em>SOD</em> activity and protein content did not differ significantly between groups in any tissue. We suggest that the compensatory increases in CAT (skeletal muscle, cardiac muscle, kidney) and GPx (cardiac muscle), but not Total-<em>SOD</em> activities, resulting from long-term cold exposure may reflect the elevated metabolic rate, and possibly also increased ROS production, at this time.

Exercise training ameliorates age-related impairments in endothelium-dependent vasodilation in skeletal muscle arterioles. Additionally, exercise training is associated with increased superoxide production. The purpose of this study was to determine the role of superoxide and superoxide-derived reactive oxygen species (ROS) signaling in mediating endothelium-dependent vasodilation of soleus muscle resistance arterioles from young and old, sedentary and exercise-trained rats. Young (<em>3</em> mo) and old (22 mo) male rats were either exercise trained or remained sedentary for 10 wk. To determine the impact of ROS signaling on endothelium-dependent vasodilation, responses to acetylcholine were studied under control conditions and during the scavenging of superoxide and/or hydrogen peroxide. To determine the impact of NADPH oxidase-derived ROS, endothelium-dependent vasodilation was determined following NADPH oxidase inhibition. Reactivity to superoxide and hydrogen peroxide was also determined. Tempol, a scavenger of superoxide, and inhibitors of NADPH oxidase reduced endothelium-dependent vasodilation in all groups. Similarly, treatment with catalase and simultaneous treatment with tempol and catalase reduced endothelium-dependent vasodilation in all groups. Decomposition of peroxynitrite also reduced endothelium-dependent vasodilation. Aging had no effect on arteriolar protein content of <em>SOD</em>-1, catalase, or glutathione peroxidase-1; however, exercise training increased protein content of <em>SOD</em>-1 in young and old rats, catalase in young rats, and glutathione peroxidase-1 in old rats. These data indicate that ROS signaling is necessary for endothelium-dependent vasodilation in soleus muscle arterioles, and that exercise training-induced enhancement of endothelial function occurs, in part, through an increase in ROS signaling.

We investigated the effect of dehydroascorbic acid (DHA), the oxidized form of vitamin C which is a superoxide scavenger, on manganese superoxide dismutase (Mn<em>SOD</em>), copper-zinc <em>SOD</em> (CuZn<em>SOD</em>), cyclooxygenase-2 (COX-2) and interleukin-1beta (IL-1beta) expression in a rat model of focal cerebral ischemia under normo- and hyperglycemic conditions. Edema formation was also assessed. Mn<em>SOD</em>, CuZn<em>SOD</em>, COX-2 and IL-1beta mRNA and protein expression were studied <em>3</em> h post-ischemia. No changes were observed in Mn<em>SOD</em> and CuZn<em>SOD</em> mRNA expression among the groups. COX-2 and IL-1beta mRNA expression were upregulated by ischemia but were not influenced by the glycemic state. At the protein level, hyperglycemic cerebral ischemia increased Mn<em>SOD</em> and CuZn<em>SOD</em> [Bémeur, C., Ste-Marie, L., Desjardins, P., Butterworth, R.F., Vachon, L., Montgomery, J., Hazell, A.S., 2004a. Expression of superoxide dismutase in hyperglycemic focal cerebral ischemia in the rat. Neurochem. Int. 45, 1167-1174] and IL-1beta expression compared to normoglycemic ischemia. COX-2 protein expression was also significantly higher following hyperglycemic ischemia compared to hyperglycemic shams. DHA administration did not change the pattern of COX-2 or IL-1beta mRNA expression, but normalized the increased protein expression following hyperglycemic ischemia. DHA administration also normalized Mn<em>SOD</em> and CuZn<em>SOD</em> protein expression to the levels observed in normoglycemic ischemic animals. Edema formation was significantly reduced by DHA administration in hyperglycemic ischemic animals. The DHA-induced post-transcriptional normalization of Mn<em>SOD</em>, CuZn<em>SOD</em>, COX-2 and IL-1beta levels and the decreased edema formation suggest that hyperglycemia accelerates superoxide formation and the inflammatory response, thus contributing to early damage in hyperglycemic stroke and strategies to scavenge superoxide should be an important therapeutic avenue.

BACKGROUND

The reported health benefits of Korean red ginseng (KRG) include antioxidant, antitumor, antimutagenic, and immunomodulatory activities; however, the effects on oxidative stress have not yet been evaluated. Therefore, we assessed the effect of KRG on antioxidant enzymes and oxidative stress markers in humans.

METHODS

We conducted a randomized, double-blind, placebo-controlled study with three groups, including placebo, low-dose (<em>3</em> g/day), and high-dose (6 g/day), which were randomly assigned to healthy subjects aged 20-65 years. Lymphocyte DNA damage, antioxidative enzyme activity, and lipid peroxidation were assessed before and after the 8-week supplementation.

RESULTS

Fifty-seven subjects completed the protocol. Plasma superoxide dismutase (SOD) activity after the 8-week KRG supplementation was significantly higher in the low-and high-dose groups compared to baseline. Plasma glutathione peroxidase (GPx) and catalase activities were also increased after the high-dose supplementation. Furthermore, the DNA tail length and tail moment were significantly reduced after the supplementation (low-dose and high-dose), and plasma oxidized low-density lipoprotein (LDL) levels were reduced in low-dose and high-dose groups, but increased in the placebo group. The net changes in oxidized LDL after the supplementation differed significantly between both KRG supplementation groups and the placebo group. Net changes in GPx, SOD and catalase activities, and DNA tail length and tail moment were significantly different between the high-dose group and the placebo group. Additionally, the net changes in urinary 8-epi-PGF(2α) were significantly different between the KRG supplementation groups and the placebo group.

CONCLUSIONS

KRG supplementation may attenuate lymphocyte DNA damage and LDL oxidation by upregulating antioxidant enzyme activity.

OBJECTIVE

To investigate the potential protective effects of amitriptyline and fluoxetine in a catecholamine cell model.

METHODS

Cultured rat pheochromocytoma (PC12) cells were pretreated with amitriptyline or fluoxetine for 24 or 48 hours and were then subjected to neurotoxic insult (200 micromol/L hydrogen peroxide). Cell viability was determined by measurement of the reduction product of <em>3</em>-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT). The enzyme activity of superoxide dismutase (<em>SOD</em>) was determined by a commercial <em>SOD</em> assay kit.

RESULTS

The decrease in cell viability induced by hydrogen peroxide was attenuated in PC12 cells pretreated with 100 micromol/L amitriptyline for 24 hours or with 50 micromol/L amitriptyline or 50 micromol/L fluoxetine for 48 hours. Pretreatment with either amitriptyline or fluoxetine was associated with increased SOD activity in PC12 cells. Inhibition of SOD activity with diethyldithiocarbamic acid reduced the cytoprotective action of fluoxetine.

CONCLUSIONS

These data suggest that the neuroprotective actions of some antidepressants include the upregulation of SOD activity.

Middle-aged and old left ventricles (LVs) are structurally and functionally very similar. Compared to a young LV, both show increased wall thickness and increased cavity size, with preserved cardiac function. However, when a stressor such as myocardial infarction occurs, striking differences are revealed between young and old LVs and there is a marked reduction in survival rates for the old group. The objective of this study was to investigate the proteomic basis of age-related changes in the LV of male mice in order to identify proteins that are differentially expressed between middle-aged and old groups and to gain mechanistic insight into effects of aging on the unstressed heart. Young (<em>3</em> months old; n = 6), middle-aged (MA; 15 months old; n = 6), and old (2<em>3</em> months old; n = 5) LVs were examined by echocardiography, homogenized, and separated into soluble and insoluble protein fractions using differential extraction. We found that the LV mass-to-tibia ratio increased from 6.4 +/- 0.2 mg/mm in young to 11.0 +/- 0.6 and 10.1 +/- 0.7 mg/mm in MA and old, respectively (both p < 0.05 vs young), which was caused by increases in both LV wall thickness and volume. Using two-dimensional gel electrophoresis, we detected age-related alterations in the levels of 7<em>3</em> proteins (all p < 0.05). Among these proteins were mortalin, peroxiredoxin <em>3</em>, epoxide hydrolase, and the superoxide dismutases <em>SOD</em>-1 (Cu/Zn<em>SOD</em>) and <em>SOD</em>-2 (Mn<em>SOD</em>), which have been previously associated with aging and/or cardiovascular disease. Together, these results reveal proteomic changes that occur in the LV with age. The proteins identified here may be useful markers of cardiac aging and may help in deducing mechanisms to explain the inability of the old heart to withstand challenge.

In this paper, the protective effect of the bioflavonoid quercetin on behaviors, antioxidases, and neurotransmitters in 1-methyl-4-phenyl-1, 2, <em>3</em>, 6-tetrahydropyridine-(MPTP-) induced Parkinson's disease (PD) was investigated. Quercetin treatment (50 mg/kg, 100 mg/kg and 200 mg/kg body weight) was orally administered for 14 consecutive days. The results show that quercetin treatment markedly improves the motor balance and coordination of MPTP-treated mice. Significant increases were observed in the activities of glutathione peroxidase (GPx), superoxide dismutase (<em>SOD</em>), and Na(+), K(+)-ATPase, AchE, the content of dopamine (DA) in the quercetin plus MPTP groups compared to those in the MPTP group. Significant reduction the 4-hydroxy-2-nonenal (4-HNE) immunoreactivity in striatum of brains was observed in the quercetin plus MPTP groups in comparison to the MPTP group. Taken together, we propose that quercetin has shown antiparkinsonian properties in our studies. More work is needed to explore detailed mechanisms of action.

The survival of pancreatic islet beta-cell xenografts and allografts may be affected by damaging reactive oxygen and nitrogen species generated during hypoxia-reoxygenation. Peroxynitrite, which is formed from superoxide and nitric oxide, appears to be an important mediator of beta-cell destruction. The intracellular antioxidant enzymes glutathione peroxidase-1 (Gpx-1) and copper-zinc superoxide dismutase (CuZn <em>SOD</em>) detoxify peroxynitrite and superoxide, respectively. The aim of this study was to examine whether enhanced expression of Gpx-1 and/or CuZn <em>SOD</em> protected NIT-1 mouse insulinoma cells from hypoxia-reoxygenation injury. Stable transfectants expressing human Gpx-1 or CuZn <em>SOD</em> were isolated and tested for their resistance to hydrogen peroxide (H(2)O(2)) and menadione, which generates superoxide intracellularly. Clones expressing one or both enzymes were subjected to hypoxia in glucose-free medium for 18 h, followed by reoxygenation in complete medium for 1.5 h. Cell viability was measured using the <em>3</em>-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) reduction assay. Increases of up to two fold in Gpx or total <em>SOD</em> activity protected NIT-1 cells from H(2)O(2) and menadione. Expression of Gpx-1 significantly increased NIT-1 survival following hypoxia-reoxygenation (viability 65 +/- 9% vs. control 15 +/- <em>3</em>%, P < 0.001) but CuZn <em>SOD</em> expression had no effect (15 +/- 1%). Expression of both enzymes was no more protective (60 +/- 6%) than expression of Gpx-1 alone. Genetic manipulation of islet beta cells to increase expression of Gpx-1 may protect them from oxidative injury associated with the transplantation procedure.

Plants of Najas indica bioaccumulated significantly higher amounts of Pb (<em>3</em>554 microg g(-1) dw) when, exposed to varying concentrations of Pb(NO(<em>3</em>))(2).This also led to increased malondialdehyde (MDA), electrical conductivity (EC) and H(2)O(2) content. In response to this, the activities of antioxidant enzymes such as superoxide dismutase (<em>SOD</em>), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT) and glutathione reductase (GR) were elevated along with the induction of various molecular antioxidants including GSH, cysteine, ascorbic acid and proline. Further, Pb exposed plants showed significantly increased cysteine synthase and glutathione-S-transferase activity. Visible symptoms of toxicity were evident at 50 microM after 4d showing chlorosis and fragmentation of leaves with mucilaginous discharge. It seems that bioaccumulated Pb is efficiently tolerated by Najas plants through activation of antioxidant system and thiolic pathways which was evident by the increased biomass up to 10 microM Pb. Therefore, it appears that due to metal tolerance characteristics with high concentration factor these plants can find use in phytoremediation of aquatic system highly contaminated by Pb.

Previous studies have shown that exposure of Swiss <em>3</em>T<em>3</em> cells to mainstream cigarette smoke (CS) trapped in phosphate-buffered saline (smoke-bubbled PBS) resulted in the expression of stress response genes, i.e. haem oxygenase and c-fos, partial inhibition of protein phosphatases 1 and 2A, as well as partial depletion of the cellular glutathione (GSH) pool. Using c-fos gene expression in Swiss <em>3</em>T<em>3</em> cells as an indicator for a cellular response against oxidative stress, the following observations are consistent with peroxynitrite as an active principal formed by CS in aqueous solutions: (i) sustained c-fos expression was obtained for smoke-bubbled PBS, peroxynitrite itself and a compound known to stoichiometrically release superoxide and nitric oxide (NO) (<em>3</em>-morpholino-sydnonimine, SIN-1); (ii) c-fos expression in cells exposed to aqueous smoke fractions was inhibited by either the superoxide-scavenging enzyme superoxide dismutase (<em>SOD</em>), in combination with catalase, or the NO-scavenger oxyhaemoglobin (HbO2); and (iii) activation of guanylate cyclase in rat lung cells was observed only when bubbling was performed with filtered smoke and with whole smoke in the presence of <em>SOD</em>/catalase. These results are consistent with a rapid NO-consuming reaction coupled with superoxide-generating properties of the particulate phase of CS. Moreover, (iv) the half-life of the c-fos-inducing activity in smoke-bubbled PBS was found to be <1 h which can be explained by a sustained peroxynitrite formation. Finally, depletion of intracellular thiol levels by smoke-bubbled PBS appears to favour the activation of a redox-sensitive component of the c-fos-inducing pathway.

Albumin induces oxidative stress and cytokine production in proximal tubular cells (PTECs). Albumin-bound fatty acids (FAs) enhance tubulopathic effects of albumin in vivo. We proposed that FA aggravation of albumin-induced oxidative stress in PTECs might be involved. We hypothesized that mitochondria could be a source of such stress. Using a fluorescent probe, we compared reactive oxygen species (ROS) production after exposure of PTECs to bovine serum albumin (BSA) alone or loaded with oleic acid (OA-BSA) (<em>3</em>-<em>3</em>0 g/l for 2 h). There was no difference in cellular albumin uptake, but OA-BSA dose-dependently induced more ROS than BSA alone (P<0.001). OA-BSA-induced ROS was significantly alleviated by mitochondrial inhibition, but not by inhibitors of nicotinamide adenine dinucleotide phosphate hydrogenase (NADPH) oxidase, xanthine oxidase, or nitric oxide synthase. Gene expression analysis showed that neither the NADPH oxidase component p22phox nor xanthine oxidase was induced by BSA or OA-BSA. OA-BSA, in contrast to BSA, failed to induce mitochondrial manganese superoxide dismutase 2 (<em>SOD</em>2) expression. OA-BSA showed a greater capacity than BSA to downregulate heme oxygenase-1 mRNA expression and accentuate inflammatory cytokine mRNA and protein. Supplementation of <em>SOD</em> activity with EUK-8 reduced ROS, and interleukin-6 protein expression was suppressed by both mitochondrial inhibition and <em>SOD</em> augmentation. Thus, in PTECs, FAs accentuate albumin-induced oxidative stress and inflammatory cytokine expression via increased mitochondrial ROS, while frustrating protective antioxidant responses.

Our objective was to test the hypothesis that short-term exercise training (STR) of pigs increases endothelium-dependent dilation (EDD) of coronary arteries but not coronary arterioles. Female Yucatan miniature swine ran on a treadmill for 1 h, at <em>3</em>.5 mph, twice daily for 7 days (STR; n = 28). Skeletal muscle citrate synthase activity was increased in STR compared with sedentary controls (Sed; n = 26). Vasoreactivity was evaluated in isolated segments of conduit arteries (1-2 mm ID, <em>3</em>-4 mm length) mounted on myographs and in arterioles (50-100 microm ID) isolated and cannulated with micropipettes with intraluminal pressure set at 60 cmH(2)O. EDD was assessed by examining responses to increasing concentrations of bradykinin (BK) (conduit arteries 10(-12)-10(-6) M and arterioles 10(-1<em>3</em>)-10(-6) M). There were no differences in maximal EDD or BK sensitivity of coronary arterioles from Sed and STR hearts. In contrast, sensitivity of conduit arteries (precontracted with PGF(2alpha)) to BK was increased significantly (P < 0.05) in STR (EC(50), 2.<em>3</em><em>3</em> +/- 0.62 nM, n = 12) compared with Sed animals (EC(50), <em>3</em>.88 +/- 0.62 nM, n = 1<em>3</em>). Immunoblot analysis revealed that coronary arteries from STR and Sed animals had similar levels of endothelial nitric oxide synthase (eNOS). In contrast, eNOS protein was increased in STR aortic endothelial cells. Neither protein nor mRNA levels of eNOS were different in coronary arterioles from STR compared with Sed animals. STR did not alter expression of superoxide dismutase (<em>SOD</em>-1) protein in any artery examined. We conclude that pigs exhibit increases in EDD of conduit arteries, but not in coronary arterioles, at the onset of exercise training. These adaptations in pigs do not appear to be mediated by alterations in eNOS or <em>SOD</em>-1 expression.