Our present study was conducted to investigate whether liquiritin (7-hydroxy-2-[4-[<em>3</em>,4,5-trihydroxy-6-(hydroxymethyl) oxan-2-yl] oxyphenyl]-chroman-4-one, 1), an active component of Glycyrrhiza uralensis Fisch., exerts a neuroprotective effect against focal cerebral ischemia/reperfusion (I/R) in male Institute of Cancer Research (ICR) mice. On the establishment of mice with middle cerebral artery occlusion (MCAO) for 2 h and reperfusion for 22 h, liquiritin at the doses of 40, 20, and 10 mg/kg was administered before MCAO once a day intragastrically for a subsequent <em>3</em> days. Neurological deficits and infarct volume were measured, respectively. The levels of malondialdehyde (MDA) and carbonyl, activities of superoxide anion (<em>SOD</em>), catalase (CAT) and glutathion peroxidase (GSH-Px) and reduced glutathione/oxidized disulfide (GSH/GSSG) ratio in brain were estimated spectrophotometrically. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) and terminal deoxynucleotidyl transferase-mediated DuTP-biotin nick end labeling (TUNEL)-positive cells were detected by immunohistochemical analysis. Our results showed that the neurological deficits, infarct volume, and the levels of MDA and carbonyl decreased, the ratio of GSH/GSSG and the activities of <em>SOD</em>, CAT, and GSH-Px were compensatorily up-regulated, and 8-OHdG and TUNEL-positive cells decreased after 22 h of reperfusion in liquiritin-treated groups. These findings suggest that liquiritin might be a potential agent against cerebral I/R injury in mice by its antioxidant and antiapoptosis properties.

The role of oxidative stress in the pathogenesis of liver disease in Wilson disease (WD), a genetic disorder characterized by excess hepatic deposition of copper that generates free radicals, remains unclear. This study investigates oxidative stress on the liver and hepatic antioxidant responses in WD using liver specimens from affected patients showing mild liver damage (group I, n = <em>3</em>), moderate or greater liver damage (group II, n = 5), and fulminant hepatic failure (group III, n = 5) and from asymptomatic carriers (n = 2). Decreased ratios of reduced glutathione (GSH) to oxidized glutathione (GSSG) and increased thiobarbituric acid reactive substance (TBARS), a lipid peroxidation product, were found in every affected patient, especially in group II and III patients. Activities and protein expressions of Mn-dependent superoxide dismutase (Mn-<em>SOD</em>), CuZn-dependent superoxide dismutase (CuZn-<em>SOD</em>), and catalase were decreased in all patients, especially in group III patients. Glutathione peroxidase (GPx) activity was decreased only in group III patients. Asymptomatic carriers without any clinical manifestations showed normal TBARS level and GSH/GSSG ratio with increases in both GSH and GSSG levels. Their CuZn-<em>SOD</em>, Mn-<em>SOD</em>, and catalase activities were increased. These results suggest that excessive copper-derived oxidants contribute to development and progression of liver disease in WD.

Since gastrointestinal mucosa is constantly exposed to reactive oxygen species from various sources, the presence of antioxidants may contribute to the body's natural defenses against inflammatory diseases.

OBJECTIVE

To define the polyphenols extracted from dried apple peels (DAPP) and determine their antioxidant and anti-inflammatory potential in the intestine. Caco-2/15 cells were used to study the role of DAPP preventive actions against oxidative stress (OxS) and inflammation induced by iron-ascorbate (Fe/Asc) and lipopolysaccharide (LPS), respectively.

RESULTS

The combination of HPLC with fluorescence detection, HPLC-ESI-MS TOF and UPLC-ESI-MS/MS QQQ allowed us to characterize the phenolic compounds present in the DAPP (phenolic acids, flavonol glycosides, flavan-<em>3</em>-ols, procyanidins). The addition of Fe/Asc to Caco-2/15 cells induced OxS as demonstrated by the rise in malondialdehyde, depletion of n-<em>3</em> polyunsaturated fatty acids, and alterations in the activity of endogenous antioxidants (<em>SOD</em>, GPx, G-Red). However, preincubation with DAPP prevented Fe/Asc-mediated lipid peroxidation and counteracted LPS-mediated inflammation as evidenced by the down-regulation of cytokines (TNF-α and IL-6), and prostaglandin E2. The mechanisms of action triggered by DAPP induced also a down-regulation of cyclooxygenase-2 and nuclear factor-κB, respectively. These actions were accompanied by the induction of Nrf2 (orchestrating cellular antioxidant defenses and maintaining redox homeostasis), and PGC-1α (the "master controller" of mitochondrial biogenesis).

CONCLUSIONS

Our findings provide evidence of the capacity of DAPP to reduce OxS and inflammation, two pivotal processes involved in inflammatory bowel diseases.

Emerging evidence has shown that acute heat exposure affects metabolic characteristics and causes oxidative damage to skeletal muscle in birds. Little is known, however, about such phenomena under chronic heat stress conditions. To address this, we designed the present study to determine the influence of cyclic (<em>3</em>2 to 24 to <em>3</em>2 degrees C: <em>3</em>2 degrees C for 8 h/d, <em>3</em>2-24-<em>3</em>2HS ), and constant (<em>3</em>2 and <em>3</em>4 degrees C, <em>3</em>2HS and <em>3</em>4HS, respectively) heat exposure on the metabolic and peroxide status in skeletal muscle of 4-wk-old male broiler chickens. Heat stress, particularly in the <em>3</em>2HS and <em>3</em>4HS groups, depressed feed intake and growth, while cyclic high temperature gave rise to a less severe stress response in performance terms. Malondialdehyde (MDA) levels in skeletal muscle were enhanced (P<0.05) by constant heat treatment; the degree of enhancement was not as large as the changes observed in our previous 'acute' heat stress model. The <em>3</em>HADH (<em>3</em>-hydroxyacyl CoA dehydrogenase related to fatty acid oxidation) and CS (citrate synthase) enzyme activities were lowered (P<0.05) by both the cyclic and constant <em>3</em>4HS treatments, and constant <em>3</em>4HS group, respectively. These results suggest that chronic heat exposure decreases metabolic oxidation capacity in skeletal muscle of broiler chickens. On exposure to chronic heat stress, GPx activity remained relatively constant, though a temperature-dependent elevation in Cu/Zn-<em>SOD</em> activity was observed, implying that anti-oxidation ability was disturbed by the chronic stress condition. From these results it can be concluded that chronic heat stress did not induce oxidative damage to a major extent. This may probably be due to a decrease in metabolic oxidation capacity or due to a self-propagating scavenging system, though the system was not fully activated.

Electron spin resonance spin trapping was utilized to investigate free radical generation from cobalt (Co) mediated reactions using 5,5-dimethyl-1-pyrroline (DMPO) as a spin trap. A mixture of Co with water in the presence of DMPO generated 5,5-dimethylpyrroline-(2)-oxy(1) DMPOX, indicating the production of strong oxidants. Addition of superoxide dismutase (<em>SOD</em>) to the mixture produced hydroxyl radical (.OH). Catalase eliminated the generation of this radical and metal chelators, such as desferoxamine, diethylenetriaminepentaacetic acid or 1,10-phenanthroline, decreased it. Addition of Fe(II) resulted in a several fold increase in the .OH generation. UV and O2 consumption measurements showed that the reaction of Co with water consumed molecular oxygen and generated Co(II). Since reaction of Co(II) with H2O2 did not generate any significant amount of .OH radicals, a Co(I) mediated Fenton-like reaction [Co(I) + H2O2->>Co(II) + .OH + OH-] seems responsible for .OH generation. H2O2 is produced from O2.- via dismutation, O2.- is produced by one-electron reduction of molecular oxygen catalyzed by Co. Chelation of Co(II) by biological chelators, such as glutathione or beta-ananyl-<em>3</em>-methyl-L-histidine alters, its oxidation-reduction potential and makes Co(II) capable of generating .OH via a Co(II)-mediated Fenton-like reaction [Co(II) + H2O2->>Co(III) + .OH + OH-]. Thus, the reaction of Co with water, especially in the presence of biological chelators, glutathione, glycylglycylhistidine and beta-ananyl-<em>3</em>-methyl-L-histidine, is capable of generating a whole spectrum of reactive oxygen species, which may be responsible for Co-induced cell injury.

Hydrophobic bile acids lead to generation of oxygen free radicals in mitochondria. Accordingly, this study investigated if gene delivery of superoxide dismutase (<em>SOD</em>) would reduce hepatic injury caused by experimental cholestasis. Rats were given adenovirus (Ad; <em>3</em> x 10(9) p.f.u., i.v.) carrying the bacterial control gene lacZ, mitochondrial Mn-<em>SOD</em> or cytosolic Cu/Zn-<em>SOD</em> genes <em>3</em> days before bile duct ligation. Both Mn- and Cu/Zn-<em>SOD</em> activity was increased in the liver about four-fold <em>3</em> days after viral infection. Serum alanine transaminase increased to about 710 U/l after bile duct ligation, which was blunted by about 70% in rats receiving Ad-Mn-<em>SOD</em>, but by only <em>3</em>0% in rats receiving Ad-Cu/Zn-<em>SOD</em>. Bile duct ligation caused focal necrosis, apoptosis and fibrosis in the liver and increased collagen alpha1 mRNA about 20-fold. These effects were reduced significantly by Ad-Mn-<em>SOD</em>, but not by Ad-Cu/Zn-<em>SOD</em>. In addition, bile duct ligation increased 4-hydroxynonenal, a product of lipid peroxidation, activated NF-kappaB and increased synthesis of TNF(alpha) and TGF-beta. These effects were also blunted significantly by Ad-Mn-<em>SOD</em>, but not by Ad-Cu/Zn-<em>SOD</em>. Taken together, it is concluded that cholestasis causes liver injury by mechanisms involving mitochondrial oxidative stress. Gene delivery of mitochondrial Mn-<em>SOD</em> blocks formation of oxygen radicals and production of toxic cytokines thereby minimizing liver injury caused by cholestasis.

Patients with intravenous heroin addiction are prone to recurrent infections and at times these infections are fatal. We evaluated the effect of morphine on the apoptosis of Jurkat cells and freshly isolated human T lymphocytes. Morphine promoted apoptosis of both the Jurkat cells and the freshly isolated T lymphocytes in a dose-dependent manner. DAGO, a specific mu receptor agonist, also promoted Jurkat cell apoptosis. DNA isolated from morphine-treated Jurkat cells and T lymphocytes also showed integer multiples of 200 base pairs. Superoxide dismutase (<em>SOD</em>) enhanced lymphocyte apoptosis; whereas catalase attenuated the morphine-induced apoptosis of Jurkat cells as well as of T lymphocytes. Morphine-treated Jurkat cells also showed a decreased expression of bcl-2 and an enhanced expression of bax. In addition, morphine-treated Jurkat cells showed activation of caspase-<em>3</em>. These results indicate that morphine-induced T lymphocyte apoptosis may be mediated through the generation of reactive oxygen species. The change in ratio of bax and bcl-2 seems to tilt the balance toward apoptosis, leading to the activation of caspase-<em>3</em>. This study provides further support for the hypothesis that morphine may be directly compromising immune function by enhancing apoptosis of T lymphocytes in patients with heroin addiction.

Lasting activations of toll-like receptors (TLRs), MAPK and NF-κB pathways can support influenza A virus (IAV) infection and promote pneumonia. In this study, we have investigated the effect and mechanism of action of emodin on IAV infection using qRT-PCR, western blotting, ELISA, Nrf2 luciferase reporter, siRNA and plaque inhibition assays. The results showed that emodin could significantly inhibit IAV (ST169, H1N1) replication, reduce IAV-induced expressions of TLR2/<em>3</em>/4/7, MyD88 and TRAF6, decrease IAV-induced phosphorylations of p<em>3</em>8/JNK MAPK and nuclear translocation of NF-κB p65. Emodin also activated the Nrf2 pathway, decreased ROS levels, increased GSH levelss and GSH/GSSG ratio, and upregulated the activities of <em>SOD</em>, GR, CAT and GSH-Px after IAV infection. Suppression of Nrf2 via siRNA markedly blocked the inhibitory effects of emodin on IAV-induced activations of TLR4, p<em>3</em>8/JNK, and NF-κB pathways and on IAV-induced production of IL-1β, IL-6 and expression of IAV M2 protein. Emodin also dramatically increased the survival rate of mice, reduced lung edema, pulmonary viral titer and inflammatory cytokines, and improved lung histopathological changes. In conclusion, emodin can inhibit IAV replication and influenza viral pneumonia, at least in part, by activating Nrf2 signaling and inhibiting IAV-induced activations of the TLR4, p<em>3</em>8/JNK MAPK and NF-κB pathways.

Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO) donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine). Activated macrophages were cytotoxic to Giardia trophozoites (approximately 60% dead trophozoites). The effect was inhibited >> 90%) by an NO synthase inhibitor (200 microM) and unaffected by superoxide dismutase (<em>SOD</em>, <em>3</em>00 U/ml). Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP) and sodium nitroprusside (SNP) in a dose-dependent manner (LD50 <em>3</em>00 and 50 microM, respectively). A dual NO-superoxide anion donor, <em>3</em>-morpholino-sydnonimine hydrochloride (SIN-1), did not have a killing effect in concentrations up to 1 mM. However, when <em>SOD</em> (<em>3</em>00 U/ml) was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (approximately <em>3</em>5% dead trophozoites at 1 mM). The mixtures of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (<em>3</em> mM). These results indicate that NO accounts for Giardia trophozoites killing and this effect is not mediated by peroxynitrite.

1. Myocardial injury caused by ischaemia and reperfusion comes from multiple pathogenic events, including endothelial damage, neutrophil extravasation into tissue, mast cell activation, and peroxidation of cell membrane lipids. These events are followed by myocardial cell alterations resulting eventually in cell necrosis. An enhanced formation of reactive oxygen species is widely accepted as a stimulus for tissue destruction and cardiac failure. 2. In this study, we have investigated the cardioprotective effects of M4040<em>3</em> in myocardial ischaemia-reperfusion injury. M4040<em>3</em> is a low molecular weight, synthetic manganese containing superoxide dismutase mimetic (<em>SOD</em>m) that selectively removes superoxide anion. Ischaemia was induced in rat hearts in vivo by ligating the left anterior descending coronary artery. Thirty minutes after the induction of ischaemia, the ligature was removed and reperfusion allowed to occur for at least 60 min. M4040<em>3</em> (0.1-1 mg kg(-1)) was given intravenously 15 min before ischaemia. <em>3</em>. The results obtained in this study showed that M4040<em>3</em> significantly reduced the extent of myocardial damage, mast cell degranulation and the incidence of ventricular arrhythmias. Furthermore, M4040<em>3</em> significantly attenuated, in a dose-dependent manner, neutrophil infiltration in the myocardium as well as the associated induction of lipid peroxidation. Calcium overload seen post-reperfusion of the ischaemic myocardium was also reduced by M4040<em>3</em>. 4. Immunohistochemical analysis for nitrotyrosine revealed a positive staining in cardiac tissue taken after reperfusion: this was attenuated by M4040<em>3</em>. Moreover reperfused cardiac tissue sections showed positive staining for P-selectin and for anti-intercellular adhesion molecule (ICAM-1) in the vascular endothelial cells. M4040<em>3</em> treatment markedly reduced the intensity and degree of P-selectin and ICAM-1 in these tissues. No staining for nitrotyrosine, P-selectin or ICAM-1 was found in cardiac tissue taken at the end of the ischaemic period. 5. Overall, M4040<em>3</em> treatment reduced the morphological signs of myocardial cell injury and significantly improved survival. 6. Taken together, these results clearly indicate that M4040<em>3</em> treatment exerts a protective effect against ischaemia-reperfusion-induced myocardial injury, supporting a key role for superoxide anion in reperfusion injuries. This suggests that synthetic enzymes of <em>SOD</em> such as M4040<em>3</em>, offer a novel therapeutic approach for the treatment of ischaemic heart disease where superoxide anion plays a dominant role.

BACKGROUND

Huang-Lian-Jie-Du-Decotion (HLJDD, Hwangryun-Hae-Dok-Decotion in Japan), an ancient antipyretic and detoxifying traditional Chinese medicine formula, was reported to have protective effect on ischemic stroke.

UNASSIGNED

To investigate the therapeutic effect of HLJDD on ischemic stroke and explore its mode of action.

METHODS

A model of ischemic stroke in the rat was established after transient middle cerebral artery occlusion (MCAO) followed by reperfusion. Rats were assigned randomly to groups of control, sham, transient ischemia/reperfusion (I/R), and three treatment groups by HLJDD at 2.5, 5.0, 10.0mg/kg. The neurological deficit, the cerebral infarct size, morphology abnormality, biochemical parameters were examined, and the levels of relevant proteins were determined by immunoblotting analysis to evaluate the protective effects of HLJDD on ischemic stroke and explore the underlying mechanism.

RESULTS

Compared with I/R group, HLJDD significantly ameliorated neurological deficit and histopathology changes, decreased infarct area, and restored the levels of biochemical indicators including nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), glutathione disulfide (GSSG), total superoxide dismutase (T-<em>SOD</em>), Cu/Zn-<em>SOD</em>, Mn-<em>SOD</em> and glutathione peroxidase (GSH-PX). HLJDD also notably elevated the levels of microtubule-associated protein 1 light chain <em>3</em> (LC<em>3</em>), Beclin-1, and other autophagy related genes (Atgs), promoted the activation of extracellular signal-regulated kinases (ERK), protein kinase B (Akt), <em>3</em>-phosphoinositide-dependent kinase (PDK1), and inhibited the activation of mammalian target of rapamycin (mTOR), c-Jun N-terminal protein kinases (JNK), p<em>3</em>8, phosphatase and tensin homolog (PTEN).

CONCLUSIONS

HLJDD showed neuroprotective effects on ischemic stroke, at least in part to the induced protective autophagy via the regulation of mitogen-activated protein kinase (MAPK) signals. This Akt-independent protective autophagy is favorable in the treatment of stroke, avoiding unfavorable side-effects associated with the inactivation of Akt. The efficacy of HLJDD on ischemic stroke and its safety warranted by its long-term clinical use in traditional Chinese medicine favored further study to develop HLJDD as an effective therapeutic agent to treat ischemic stroke.

Extracellular superoxide dismutase (<em>SOD</em><em>3</em>) is highly expressed in renal tissues and a critical regulator of vascular function. We hypothesized that deletion of <em>SOD</em><em>3</em> would attenuate recovery of renal blood flow (RBF) and increase oxidative stress and injury following renal ischemia/reperfusion (I/R). To test this, we evaluated <em>SOD</em> expression and activity, basal superoxide production, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in kidneys from male and female wild-type (WT) and <em>SOD</em><em>3</em>-knockout mice. RBF, measured using an ultrasonic flow probe, and histological indices of oxidative stress and injury were assessed after 1 h of ischemia. Following ischemia, RBF was attenuated in kidneys from male, but not female, knockout mice compared with their WT counterparts. Total <em>SOD</em> activity was significantly reduced in male knockout compared with WT male mice but was similar in female mice of both genotypes, suggesting upregulated <em>SOD</em>1 activity. Basal superoxide production and NADPH oxidase activity were unrelated to the differences in RBF. After 24 h, kidneys from both genders of knockout mice were found to have more oxidative stress (<em>3</em>-nitrotyrosine immunohistochemistry) and renal cast formation than those from WT mice. Thus, our study found a key role for <em>SOD</em><em>3</em> in regulating renal I/R injury.

Organophosphates are known primarily as neurotoxins. However, reactive oxygen species (ROS) caused by organophosphates may be involved in the toxicity of various pesticides. Therefore, in this study we aimed to examine how an organophosphate insecticide, chlorpyrifos-ethyl (CE) [0,0-diethyl 0 (<em>3</em>,5,6-trichloro-2-pyridyl) phosphorothioate], affects lipid peroxidation and the antioxidant defense system in vitro. For this purpose, four experiments were carried out. In experiment 1, erythrocyte packets obtained from six (three male, three female) volunteers were divided into six portions, and to each was added CE in both a high concentration range (0, 0.4, 2, 10, 50, 100 g/l) and a low concentration range (0, 0.01, 0.1 g/l). Additionally, each concentration group was divided into five tubes, and incubated at +4 degrees C for 0, <em>3</em>0, 60, 120, and 240 min. After incubation, the levels of malondialdehyde (MDA) and the activity of superoxide dismutase (<em>SOD</em>), glutathione peroxidase (GSH-Px), and catalase (CAT) were determined in the erythrocytes in all tubes. In experiment 2, to examine the effect of CE (or its main metabolites) on the activity of purified, commercially available enzymes, CE at concentrations of 0. 0.01, 0.1, 0.4, and 10 g/l was incubated with purified <em>SOD</em>, GSH-Px and CAT at the concentrations observed in control group at the 0 CE concentration level in experiment 1 for 1 h at room temperature (25 degrees C). In experiment <em>3</em>, the xanthine-xanthine oxidase system was used to determine whether the activities of <em>SOD</em>, GSH-Px and CAT were inactivated other than by CE, for example by superoxide radicals inducing lipid peroxidation in erythrocytes. Samples with xanthine and xanthine oxidase were mixed and incubated for 1 h at room temperature (25 degrees C). In experiment 4, to determine whether enzyme activities were still inhibited if lipid peroxidation was prevented by exogenous antioxidants, experiment 1 was repeated with the CE concentrations of 0.01, 0.1, 0.4, and 10 g/l by adding butylated hydroxytoluene and vitamin E to the medium. The MDA levels were determined spectrophotometrically. Enzymatic methods were used for the determination of <em>SOD</em>, GSH-Px, and CAT activities. The Friedman test and Wilcoxon's Signed Ranks test were used to compare paired groups. MDA values and GSH-Px activities increased with increasing CE concentration and incubation period (P<0.05), but <em>SOD</em> and CAT activities decreased with increasing CE concentration and incubation period (P<0.01). From these results, it can be concluded that in vitro administration of CE resulted in the induction of erythrocyte lipid peroxidation and significant changes in antioxidant enzyme activities, suggesting that ROS and/or free radicals may be involved in the toxic effects of CE.

OBJECTIVE

Stroke is a devastating disease. Both excitotoxicity and oxidative stress play important roles in ischemic brain injury, along with harmful impacts on ischemic cerebral tissue. As guanosine plays an important neuroprotective role in the central nervous system, the purpose of this study was to evaluate the neuroprotective effects of guanosine and putative cerebral events following the onset of permanent focal cerebral ischemia.

METHODS

Permanent focal cerebral ischemia was induced in rats by thermocoagulation. Guanosine was administered immediately, 1 h, <em>3</em> h and 6 h after surgery. Behavioral performance was evaluated by cylinder testing for a period of 15 days after surgery. Brain oxidative stress parameters, including levels of ROS/RNS, lipid peroxidation, antioxidant non-enzymatic levels (GSH, vitamin C) and enzymatic parameters (<em>SOD</em> expression and activity and CAT activity), as well as glutamatergic parameters (EAAC1, GLAST and GLT1, glutamine synthetase) were analyzed.

RESULTS

After 24 h, ischemic injury resulted in impaired function of the forelimb, caused brain infarct and increased lipid peroxidation. Treatment with guanosine restored these parameters. Oxidative stress markers were affected by ischemic insult, demonstrated by increased ROS/RNS levels, increased SOD expression with reduced SOD activity and decreased non-enzymatic (GSH and vitamin C) antioxidant defenses. Guanosine prevented increased ROS/RNS levels, decreased SOD activity, further increased SOD expression, increased CAT activity and restored vitamin C levels. Ischemia also affected glutamatergic parameters, illustrated by increased EAAC1 levels and decreased GLT1 levels; guanosine reversed the decreased GLT1 levels and did not affect the EAAC1 levels.

CONCLUSIONS

The effects of brain ischemia were strongly attenuated by guanosine administration. The cellular mechanisms involved in redox and glutamatergic homeostasis, which were both affected by the ischemic insult, were also modulated by guanosine. These observations reveal that guanosine may represent a potential therapeutic agent in cerebral ischemia by preventing oxidative stress and excitotoxicity.

The objective of this study is to evaluate the effect of allicin (10 mg/kg body weight, orally) in an experimental murine model of UC by administering 2.5% dextran sodium sulfate (DSS) in drinking water to BALB/c mice. DSS-induced mice presented reduced body weight, which was improved by allicin administration. We noted increases in CD68 expression, myeloperoxidase (MPO) activities, and Malonaldehyde (MDA) and mRNA levels of proinflammatory cytokines, such as tumor necrosis factor- (TNF-) α, interleukin- (IL-) 1β, IL-6, and IL-17, and decrease in the activities of enzymic antioxidants such as superoxide dismutase (<em>SOD</em>), Catalase (CAT), Glutathione reductase (GR), and Glutathione peroxidase (GPx) in DSS-induced mice. However, allicin treatment significantly decreased CD68, MPO, MDA, and proinflammatory cytokines and increased the enzymic antioxidants significantly (P < 0.05). In addition, allicin was capable of reducing the activation and nuclear accumulation of signal transducer and activator of transcription <em>3</em> (STAT<em>3</em>), thereby preventing degradation of the inhibitory protein IκB and inducing inhibition of the nuclear translocation of nuclear factor (NF)-κB-p65 in the colonic mucosa. These findings suggest that allicin exerts clinically useful anti-inflammatory effects mediated through the suppression of the NF-κB and IL-6/p-STAT<em>3</em>(Y705) pathways.

Rheumatoid arthritis (RA) is a prevalent and debilitating autoimmune disease that affects the joints. RA is characterized by an infiltration of the affected joint by blood-derived cells. In response to activation, these cells generate reactive oxygen species, resulting in an oxidative stress situation. One approach to counteract this oxidative stress situation is the use of antioxidants as therapeutic agents. The free radical scavenger enzyme superoxide dismutase (<em>SOD</em>) may be used as a therapeutic agent in rheumatoid arthritis, but its rapid elimination from the circulation is a major limitation. Targeted delivery of <em>SOD</em> may overcome this limitation. In this study, the utility of PEGylated liposomes (PEG-liposomes) for targeting <em>SOD</em> to arthritic sites was explored. The targeting of <em>SOD</em> to arthritic sites following intravenous administration of both PEG-liposomes and positively charged liposomes lacking PEG but containing stearylamine (SA-liposomes) in rats with adjuvant arthritis was studied. At 24 h post injection, the blood levels of long circulating liposomes with a mean size of 0.11 micrometer and 0.20 micrometer were 8- and <em>3</em>-fold higher, respectively, as compared to the SA-liposomes. The majority of <em>SOD</em> administered in liposomal form remains within the liposomes when they circulate in the bloodstream. The highest target uptake was observed with PEG-liposomes with a mean size of 0.11 micrometer and the lowest uptake with the SA-liposomes. These results demonstrate that <em>SOD</em> can be targeted to inflamed sites most efficiently via small-sized PEG-liposomes. Small-sized PEG-coated liposomes are to be preferred if prolonged circulation and enhanced localization of <em>SOD</em> at arthritic sites are desired.

The lipid peroxidation (as malondialdehyde, MDA), activities of superoxide dismutase (<em>SOD</em>) and catalase (CAT), and benzo[a]pyrene (BaP) metabolites were investigated in sera and erythrocytes of male Sprague-Dawley rats treated with BaP (20 mg per rat). MDA levels were significantly increased in sera (16.98+/-<em>3</em>.29 nmol/ml serum, P<0.05) 12 h after BaP treatment and persisted up to 96 h (1<em>3</em>.80+/-1. 65 nmol/ml serum, P<0.05), but no significant change in NIDA levels was observed in erythrocytes. <em>SOD</em> and CAT activities were significantly increased in erythrocytes shortly after BaP exposure, and they were slightly decreased in sera, indicating an inverse correlation between lipid peroxidation and antioxidant enzyme activity. BaP and BaP-quinones (BaP-1,6-quinone and BaP-<em>3</em>,6-quinone) were measured in sera during the study period. A rapid increase of unmetabolized BaP was observed in sera (41.27+/-4.14 pmol/ml serum) <em>3</em> h after BaP treatment, reaching a peak at 6 h (48.56+/-4.62 pmol/ml serum) followed by a sharp decrease. Formation of the BaP-1, 6-quinone and BaP-<em>3</em>,6-quinone started in sera <em>3</em> h after BaP treatment, reached a peak at 24 h (7.2<em>3</em>+/-1.02 pmol/ml serum) and 12 h (9.20+/-0.98 pmol/ml serum), respectively, and then decreased gradually. The time-dependent pattern of serum lipid peroxidation and the level of erythrocyte antioxidant enzymes were shown to be related to the concentrations of the BaP-quinone metabolites. These results suggest that BaP treatment, probably via the formation of BaP-quinones, oxidatively altered lipids and antioxidant enzymes in the blood, and might be associated with BaP-related vascular toxicity including carcinogenesis.

To investigate the effects of selenium or beta-carotene supplementation in human immunodeficiency virus (HIV)-infected patients, who are known to have deficiencies of selenium and vitamin A, we evaluated the blood enzymatic antioxidant system, including superoxide dismutase (<em>SOD</em>), selenodependent glutathione peroxidase (GPX), and catalase (Cat); glutathione (GSH) status; and plasma selenium concentration. The placebo group consisted of 18 HIV-infected patients with no supplementation, the selenium group was composed of 14 patients receiving oral selenium treatment, and the beta-carotene group comprised 1<em>3</em> patients receiving oral beta-carotene supplementation. All groups were studied for 1 y. At the beginning of the study, a significantly higher <em>SOD</em> activity (P < 0.001) was observed in all HIV-infected patients compared with uninfected control subjects, and GPX activity at baseline was higher in the placebo (P < 0.004) and selenium (P < 0.014) groups than in the control subjects. These higher enzyme activities could be related to an increased synthesis of these enzymes in erythrocyte precursors under oxidative stress. Moreover, we observed significantly lower GSH values in all HIV-infected patients than in control subjects at the beginning of the study (P < 0.001). After selenium or beta-carotene supplementation, no significant difference was observed for <em>SOD</em> activity compared with baseline. On the contrary, GPX activity increased significantly after selenium treatment (P < 0.04 between <em>3</em> and 6 mo), whereas a slight increase was found after beta-carotene treatment. Similarly, a significant increase in GSH values was observed at 12 mo compared with baseline both after selenium supplementation (P < 0.001) and beta-carotene supplementation (P < 0.01). Because GPX and GSH play an important role in the natural enzymatic defense system in detoxifying hydrogen peroxide in water, selenium supplementation could be of great interest in protecting cells against oxidative stress. The lower efficiency of beta-carotene could be attributed to the seriousness of the pathology at the time of recruitment into the beta-carotene group.

OBJECTIVE

The aim of this study is to investigate the roles of SIRT1 and NF-κB in the pathogenesis of diabetes mellitus in rats with STZ-induced diabetes and determine the effects of hesperidin and quercetin on oxidative stress and on the levels of SIRT1 and NF-κB.

METHODS

The experimental animals were divided into four groups, each group comprising ten rats designated as follows: group 1 served as control rats (C); group 2 served as diabetic rats (DM); group <em>3</em> served as diabetic rats administered hesperidin (DM+HSP) (100mg/kg b.w.) in aqueous suspension orally for 15 days; and group 4 served as diabetic rats administered quercetin (DM+Q) (100mg/kg b.w.) in aqueous suspension orally for 15 days.

RESULTS

In diabetic group, liver and kidney SIRT1, SOD and CAT activities were significantly lower than control group (p<0.05). Hesperidin and quercetin caused significant increase in the SIRT1, SOD and CAT activities of both DM+HP and DM+Q groups kidney tissues compared to DM group (p<0.05). Liver SOD activies were not found to differ significantly between DM, DM+Q and DM+HP groups (p>0.05). In DM+HP group, liver CAT activities were significantly higher than DM (p<0.05), but there was no significant difference in liver CAT activities between DM and DM+Q (p>0.05). In diabetic group, liver and kidney NF-κB and MDA levels were increased compared to control group (p<0.05), and groups of DM+HP and DM+Q had lower NF-κB and MDA levels than diabetic group (p<0.05).

CONCLUSIONS

As a conclusion, based on the results we obtained from this study and the literature data discussed above, we determined in STZ-induced diabetic rats that, increased glucose levels and liver and kidney damage markers decreased significantly after administration of hesperedin and quercetin, and that oxidative stress and NF-κB levels increased while SIRT1 levels decreased in the diabetic group.

The effects of selenium (Se) on antioxidant defense system in liver and kidneys of rats with cadmium (Cd)-induced toxicity were examined. Cd exposure (15 mg Cd/kg b.m./day as CdCl(2) for 4 weeks) resulted in increased lipid peroxidation (LP) in both organs (p<0.005 and p<0.01). Vitamin C (Vit C) was decreased in the liver (p<0.005), whereas vitamin E (Vit E) was increased in the liver and kidneys (p<0.005 and p<0.05) of Cd-exposed animals. Superoxide dismutase (<em>SOD</em>) and glutathione peroxidase (GSH-Px) activities were decreased in both tissues (p<0.05 and p<0.005), whereas catalase (CAT) activity was decreased only in liver (p<0.005). Glutathione S-transferase (GST) increased in both tissues (p<0.005 and p<0.01). Treatment with Se (0.5 mg Se/kg b.m./day as Na(2)SeO(<em>3</em>) for 4 weeks) significantly increased liver and kidneys <em>SOD</em> and GSH-Px activities (p<0.05 to p<0.005), as well as CAT and GST activities only in the liver (p<0.01). In animals exposed to Se, both the concentrations of Vit C (p<0.01) and Vit E (p<0.005) were increased in both tissues. Co-treatment with Se resulted in reversal of oxidative stress with significant decline in analyzed tissues Cd burden. Our results show that Se may ameliorate Cd-induced oxidative stress by decreasing LP and altering antioxidant defense system in rat liver and kidneys and that Se demonstrates the protective effect from cadmium-induced oxidative damage.

BACKGROUND

Cardiac failure is a leading cause of the mortality of diabetic patients. In part this is due to a specific cardiomyopathy, referred to as diabetic cardiomyopathy. Oxidative stress is widely considered to be one of the major factors underlying the pathogenesis of the disease. This study aimed to test whether the antioxidant alpha-lipoic acid (alpha-LA) could attenuate mitochondrion-dependent myocardial apoptosis through suppression of mitochondrial oxidative stress to reduce diabetic cardiomyopathy.

METHODS

A rat model of diabetes was induced by a single tail intravenous injection of streptozotocin (STZ) 45 mg/kg. Experimental animals were randomly assigned to <em>3</em> groups: normal control (NC), diabetes (DM) and DM treated with alpha-LA (alpha-LA). The latter group was administered with alpha-LA (100 mg/kg ip per day), the remainder received the same volume vehicle. At weeks 4, 8, and 12 after the onset of diabetes, cardiac apoptosis was examined by TUNEL assay. Cardiomyopathy was evaluated by assessment of cardiac structure and function. Oxidative damage was evaluated by the content of malondialdehyde (MDA), reduced glutathione (GSH) and the activity of manganese superoxide diamutase (Mn-<em>SOD</em>) in the myocardial mitochondria. Expression of caspase-9 and caspase-<em>3</em> proteins was determined by immunohistochemistry and mitochondrial cytochrome c release was detected by Western blotting.

RESULTS

At 4, 8, and 12 weeks after the onset of diabetes, significant reductions in TUNEL-positive cells, caspase-9,-<em>3</em> expression, and mitochondrial cytochrome c release were observed in the alpha-LA group compared to the DM group. In the DM group, the content of MDA in the myocardial mitochondria was significantly increased, and there was a decrease in both the mitochondrial GSH content and the activities of Mn-<em>SOD</em>. They were significantly improved by alpha-LA treatment. HE staining displayed structural abnormalities in diabetic hearts, while alpha-LA reversed this structural derangement. The index of cardiac function (+/-dp/dtmax) in the diabetes group was aggravated progressively from 4 weeks to 12 weeks, but alpha-LA delayed deterioration of cardiac function (P < 0.05).

CONCLUSIONS

Our findings indicate that the antioxidant alpha-LA can effectively attenuate mitochondria-dependent cardiac apoptosis and exert a protective role against the development of diabetic cardiomyopathy. The ability of alpha-LA to suppress mitochondrial oxidative damage is concomitant with an enhancement of Mn-SOD activity and an increase in the GSH content of myocardial mitochondria.

The current study was performed to investigate mitochondrial protection and anti-aging activity of Astragalus polysaccharides (APS) and the potential underlying mechanism. Lipid peroxidation of liver and brain mitochondria was induced by Fe(2+)-Vit C in vitro. Thiobarbituric acid (TBA) colorimetry was used to measure the content of thiobarbituric acid reactive substances (TBARS). Mouse liver mitochondrial permeability transition (PT) was induced by calcium overload in vitro and spectrophotometry was used to measure it. The scavenging activities of APS on superoxide anion (O(2) (•-)) and hydroxyl radical (•OH), which were produced by reduced nicotinamide adenine dinucleotide (NADH)-N-Methylphenazonium methyl sulfate (PMS) and hydrogen peroxide (H(2)O(2))-Fe(2+) system respectively, were measured by 4-nitrobluetetrazolium chloride (NBT) reduction and Fenton reaction colorimetry respectively. The Na(2)S(2)O(<em>3</em>) titration method was used to measure the scavenging activities of APS on H(2)O(2). APS could inhibit TBARS production, protect mitochondria from PT, and scavenge O(2) (•-), •OH and H(2)O(2) significantly in a concentration-dependent manner respectively. The back of the neck of mice was injected subcutaneously with D-galactose to induce aging at a dose of 100 mg/kg/d for seven weeks. Moreover, the activities of catalase (CAT), surperoxide dismutase (<em>SOD</em>) and glutathione peroxidase (GPx) and anti-hydroxyl radical which were assayed by using commercial monitoring kits were increased significantly in vivo by APS. According to this research, APS protects mitochondria by scavenging reactive oxygen species (ROS), inhibiting mitochondrial PT and increasing the activities of antioxidases. Therefore, APS has the effect of promoting health.

Recent studies have shown that lead (Pb) could disrupt the prooxidant/antioxidant balance of tissue which leads to biochemical and physiological dysfunction. Epigallocatechin-<em>3</em>-gallate (EGCG), a catechin polyphenols component, is found to be an effective antioxidant. The present study investigated whether EGCG administration could reverse the changes on redox states in rat hippocampus caused by lead exposure. The association between redox status changes and long-term potentiation (LTP) in CA1 area of hippocampus were also examined. Wistar rats exposed to lead from postnatal day 1 were followed by 10 days of EGCG (10, 25 and 50 mg/kg) administration through intraperitoneally (ip), and the rats were sacrificed for experiments at the age of 21-2<em>3</em> days. The experimental results showed that glutathione (GSH) and superoxide dismutase (<em>SOD</em>) activity decreased accompanied with LTP amplitude decrease in CA1 area of hippocampus in the lead-exposed group. EGCG supplementation following lead intoxication resulted in increases in the GSH and <em>SOD</em> levels and increases in the LTP amplitude. Malondialdehyde (MDA) levels, a major lipid peroxidation byproduct, increased following lead exposure and decreased following EGCG treatment. In hippocampal neuron culture model, lead exposure (20 microM) significantly inhibited the viability of neurons which was followed by an accumulation of ROS and a decrease of mitochondrial membrane potential (delta Psi m). Treatment by EGCG (10-50 microM) effectively increased cell viability, decreased ROS formation and improved delta Psi m in hippocampal neurons exposed to lead. These observations suggest that EGCG is a potential complementary agent in the treatment of chronic lead intoxication through its antioxidative character.

Oxidative stress may play a key role in the pathogenesis of diabetic nephropathy. Propolis and its extract have antioxidant properties. The effect of ethanolic extract of propolis against experimental diabetes mellitus-associated changes was examined. Diabetes was induced experimentally in rats by i.p. injection of streptozotocin (STZ) in a dose of 60 mg/kg bwt for <em>3</em> successive days. Blood urea nitrogen (BNU), creatinine, glucose, lipid profile, malondialdehyde (MDA) and urinary albumin were measured. Superoxide dimutase (<em>SOD</em>), glutathione (GSH), catalase (CAT) and MDA were measured in the renal tissue. The results showed decreased body weight and increased kidney weight in diabetic animals. Compared to the control normal rats, diabetic rats had higher blood glucose, BNU, creatinine, total cholesterol, triglycerides, low-density lipoprotein-cholesterol (LDL-C), MDA and urinary albumin and lower high-density lipoprotein-cholesterol (HDL-C) levels. Moreover, renal tissue MDA was markedly increased while <em>SOD</em>, GSH and CAT were significantly decreased. Oral administration of propolis extract in doses of 100,200 & <em>3</em>00 mg/kg bwt improved the body and kidney weights, serum glucose, lipid profile, MDA and renal function tests. Renal GSH, <em>SOD</em> and CAT were significantly increased while MDA was markedly reduced. These results may suggest a strong antioxidant effect of propolis which can ameliorate oxidative stress and delay the occurrence of diabetic nephropathy in diabetes mellitus.