mRNA Expression Of Antioxidant Enzymes Research Articles

Bioaccumulation of decabromodiphenyl ether affects the antioxidant system in the clam Mactra veneriformis

Antioxidant enzymes play vital roles against oxidative stress induced by decabromodiphenyl ether (BDE-209), being widespread in marine environment. However, the effect of BDE-209 on antioxidant enzymes remains poorly understood in marine bivalves. In this study, the clams Mactra veneriformis were exposed to 0.1, 1, and 10 μg/L BDE-209 for 7 days and then maintained in clean seawater for 3 days as the depuration. The bioaccumulation of BDE-209 and the effects on superoxide dismutase, catalase, and glutathione peroxidase were investigated. BDE-209 accumulation was concentration-dependent and decreased by 36%–52% after recovery. Malondialdehyde contents increased in a time- and dose-dependent manner. mRNA expression and activity of antioxidant enzymes changed with different patterns and recovered after depuration. These results suggested that antioxidant systems were triggered to protect the clams from oxidative damage caused by BDE-209. Thus, this research is helpful in elucidating the effect of BDE-209 on antioxidant system in marine bivalves.

Purification and characterization of Inonotus hispidus exopolysaccharide and its protective effect on acute alcoholic liver injury in mice.

This study characterized the Inonotus hispidus extracellular exopolysaccharide (IHEPS) from fermentation broth and investigated its liver protective effect on acute alcoholic liver injury in mice. The characterization of IHEPS was analyzed by HPLC, UV-vis and FT-IR. To determine the liver protective effect of IHEPS, mice were administered with IHEPS once daily for 3 weeks, before ethanol induced acute alcoholic liver injury. Biochemical parameters of liver function, histopathological sections, mRNA and protein expression of related antioxidant enzymes were compared between with or without IHEPS administrated mice. As a result, IHEPS could extend the duration of righting reflex, shorten the durations of the recovery, and decrease the liver index in acute alcoholic liver mice. At the same time, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and malondialdehyde (MDA) levels were decreased in IHEPS mice. Moreover, increased alcohol dehydrogenase (ADH), catalase (CAT) and superoxide dismutase (SOD) levels were also found in IHEPS mice. Furthermore, IHEPS activated Nrf2 signaling pathway and increased the expression of downstream related antioxidant enzymes, such as NQO1, CAT and Cu-Zn SOD.

L-arginine inhibited apoptosis of fish leukocytes via regulation of NF-κB-mediated inflammation, NO synthesis, and anti-oxidant capacity

The increased apoptosis plays an important role in bacterial invasion. In addition, LPS can induce inflammation and apoptosis of leukocytes via the production of reactive oxygen and nitrogen species. In the present study, we investigated the potential protective role of l-arginine (L-Arg) against the apoptosis of fish leukocytes in vitro. The results of Annexin V-FITC/PI staining and TUNEL assay indicated that L-Arg significantly alleviated the apoptosis of fish leukocytes induced by LPS at 24 h and 72 h post incubation (hpi). High caspase-3 activities induced by LPS at 72 hpi were significantly inhibited by L-Arg. Moreover, L-Arg supplementation also significantly decreased the mRNA expression levels of caspases at most time points, which contributed to the anti-apoptotic roles of L-Arg. Further analysis showed that L-Arg significantly inhibited the expression of several pro-inflammatory cytokines including IL-8 and TNF-α, partially via the down-regulation of the genes involved in NF-κB/MyD88 including NF-κB, IKKα and IKKγ. The down-regulation of these pro-inflammatory cytokines by L-Arg supplementation led to the further decrease in the expression of death receptor FasL, contributing to the anti-apoptotic effect of L-Arg. In addition, L-Arg supplementation increased both iNOS mRNA expression and NO production. The mRNA expressions of several anti-oxidant enzymes including SOD, CAT and GSHPx were also significantly increased after L-Arg supplementation, which accelerated the clearance of reactive oxygen species. In all, L-Arg inhibited apoptosis of fish leukocytes both via the increased NO production and antioxidant capacity and via the inhibition of inflammation mediated by NF-κB/MyD88 pathway.

Cadmium induces apoptotic program imbalance and cell cycle inhibitor expression in cultured human astrocytes

Cadmium is a highly neurotoxic heavy metal impairing neurogenesis and induces neurodegenerative disorders. Toxic concentrations of cadmium induce astrocytic apoptosis by depleting intracellular glutathione levels, elevating intracellular calcium levels, altering mitochondria membrane potentials, and activating JNK and PI3K/Akt signaling pathways. Cadmium suppresses cell proliferation in kidney epithelial cells, lung fibroblasts, and primary myelocytes; however, cadmium’s effects on proteins regulating oxidative stress, apoptosis, and cell proliferation in astrocytes are less known. The present study hypothesized that cadmium alters levels of antioxidant enzymes, apoptotic regulator proteins, and cell cycle inhibitor proteins, resulting in apoptosis and cell cycle arrest. Concentrations ≥20 μM cadmium induced apoptosis and led to intracellular changes including DNA fragmentation, reduced mRNA expression of antioxidant enzymes (i.e., catalase and glutathione S transferase-A4), downregulation of B-cell lymphoma 2 (Bcl-2), and upregulation of Bcl-2-associated X protein (Bax). Moreover, cadmium suppressed astrocytic proliferation by inducing S and G2/M phase cell cycle arrest and promoting p53, p21, and p27 expression. In conclusion, this study provides mechanistic insight into cadmium-induced cytotoxicity of astrocytes and highlights potential targets for prevention of cadmium-induced apoptosis and cell cycle arrest.

Trans10, cis12-conjugated linoleic acid exhibits a stronger antioxidant capacity than cis9, trans11-conjugated linoleic acid in primary cultures of laying hen hepatocytes

The objective of this study consisting of 2 trials was to investigate the antioxidant role of conjugated linoleic acid (CLA) isomers (c9, t11-CLA and t10, c12-CLA) and the underlying mechanism by which they act in modulating redox status in a primary laying hen hepatocyte culture. In trial 1, the cytotoxicity of CLA isomers or linoleic acid (LA) (0, 25, 50, 100, 200, 400, 800 μmol/L) was evaluated by 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay. The concentration of CLA isomers or LA (25, 50, 100 μmol/L) for proper antioxidant activity was evaluated by measuring the antioxidant enzyme activity. In trial 2, there were 5 groups: control group, cells were untreated; H2O2 group, cells were exposed to 4mmol/L H2O2 for 2h; c9, t11 or t10, c12 or LA group, cells were treated with c9, t11-CLA or t10, c12-CLA or LA for 24h and then exposed to 4mmol/L H2O2 for 2h. Trial 1 showed that the non-toxic dose range for CLA isomers was 0 to 200 μmol/L. The optimum concentration of c9, t11-CLA and t10, c12-CLA for trial 2 was 100 μmol/L. In trial 2, pretreatment with t10, c12-CLA but not c9, t11-CLA attenuated the increase in reactive oxygen species (ROS) compared to hydrogen peroxide (H2O2) group (P < 0.05). t10, c12-CLA elevated the superoxide dismutase (SOD) and catalase (CAT) activities compared with the H2O2 group (P < 0.05). In addition, t10, c12-CLA up-regulated the mRNA expression of nuclear factor E2-related factor-2 (Nrf2) as well as its target genes, Cu-Zn superoxide dismutase (SOD1) and CAT (P < 0.05). Pretreatment with t10, c12-CLA but not c9, t11-CLA decreased Nrf2 protein expression in the cytoplasm and increased Nrf2 protein expression in the nucleus compared with the H2O2 group (P < 0.05). The results indicate that t10, c12-CLA exhibits a stronger antioxidant capacity than c9, t11-CLA in primary cultured laying hen hepatocytes. t10, c12-CLA increases the activity and mRNA expression of antioxidant enzymes via facilitating nuclear translocation of Nrf2.

MRNA expression of antioxidant and biotransformation enzymes in zebrafish (Danio rerio) embryos after exposure to the tricyclic antidepressant amitriptyline

Now-a-days, the occurrence of antidepressant residues in surface waters has become a major concern. Amitriptyline (AMI) has been described to treat depression and other disorders for decades. However, little is known about its effect on non-target organisms. The aim of this study was to assess the potential impact of AMI on the mRNA expression of antioxidant and detoxification enzymes during the early embryonic development of zebrafish (Danio rerio). Fertilized D. rerio embryos were exposed to AMI at concentrations of 300 ng/L and 30 μg/L and sampled 24, 48, 96, and 144 h post fertilization (hpf) to assess the mRNA expressions of cytochrome P450 1A1, glutathione-S-transferase, glutathione peroxidase, superoxide dismutase, and catalase.The time courses of the mRNA expressions of antioxidant and detoxification enzymes revealed characteristic changes during embryonic development causing generally transient changes post hatching; however, AMI did not cause any significant impact except in the case of CAT after 144 h, which was significantly upregulated by the AMI concentration of 30 μg/L. The results suggest that the antidepressant AMI causes only moderate to minor impacts on antioxidant and detoxification enzymes during early embryonic development of the non-target organism D. rerio and that CAT is the only biomarker affected by AMI.

Antioxidant defenses at enzymatic and transcriptional levels in response to acute lead administration in Oxya chinensis

Lead (Pb) is known to be toxic to many organisms. Oxidative stress is a major mechanism of its toxicity. This research aims to investigate the effects of Pb on hydrogen peroxide (H2O2) and malonedialdehyde (MDA) contents, activities and mRNA levels of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)) after Oxya chinensis were acutely treated with lead acetate for 24 h. The results showed that the LD50-24 h value of lead acetate to O. chinensis was 1541.89 (1431.19–1655.77) μg g−1 body H2O2 and MDA contents were elevated after Pb administration, which suggested that Pb induced the overproduction of ROS and caused oxidative stress. SOD activities were significantly inhibited 40.42% of the control by 280 μg μL−1 Pb. CAT activities were increased while GPx activities had no significant changes. Different types of antioxidant-related genes had various responses to Pb stress. The transcriptions of icCuZnSOD2 and ecCuZnSOD2 were significantly inhibited by different concentrations of Pb. MnSOD mRNA levels showed the concentration-dependent rise with the Pb concentrations increase. The expressions of ecCuZnSOD1, CAT1, and GPx were significantly up-regulated while the transcriptions of icCuZnSOD1 and CAT2 had no significant changes. Alteration of activities and mRNA expressions of antioxidant enzymes implied that Pb-induced antioxidant defenses were related to modifications at enzymatic and transcriptional levels. The profiles of antioxidant enzymes and H2O2 and MDA contents and relationships among the parameters indicated that the cooperation of multiple antioxidants rather than a single factor might be responsible for the antioxidant defenses against Pb stress.

Efficacy of linalool to ameliorate uremia induced vascular calcification in wistar rats

BackgroundUremia is the condition generally associated with the last stage of chronic kidney disease (CKD) due to highly reduced glomerular filtration rate. Mortality of the patients diagnosed with Uremia generally occurs due to cardiovascular involvement. This occurs due to the transdifferentiation of vascular smooth muscle cells (VSMCs) into osteogenic cells in hyperphosphatemic condition that is associated with kidney failure promoting extra-osseous calcification. PurposeLinalool is an essential oil that has been recently studied for its procardiovascular effects, thus the aim of the study involved to identify its potential role on vascular calcification (VC). MethodsUremia was induced in male wistar rats, weighing 250–350 gm by giving adenine diet for 4 weeks followed by phosphate diet for next 4 weeks. Linalool was given orally at two different doses (100 mg/kg bodyweight and 150 mg/kg bodyweight) daily for 4 weeks with phosphate diet. ResultsLinalool being a moderate antioxidant probably scavenged superoxide radicals (in vitro analysis). Deposition of calcium was observed by alizarin and von-kossa stains in aorta of uremic rats whereas linalool co-administration prevents calcium deposition in aorta of uremic rats. Elevated mRNA expression of calcification markers, increased lipid peroxidation levels and increased levels of catalase and superoxide dismutase (SOD) was found in aorta of uremic animals. However, with supplementation of linalool reduction in the mRNA expression of calcification markers, lipid peroxidation and antioxidant enzymes were observed. ConclusionTherefore it can be concluded that linalool could be a promising therapeutic candidate for exploring its clinical application in VC.

The Protective Roles of Dietary Selenium Yeast and Tea Polyphenols on Growth Performance and Ammonia Tolerance of Juvenile Wuchang Bream (Megalobrama amblycephala).

In order to investigate protective roles of dietary selenium yeast (SY) and tea polyphenols (TPs) on growth of juvenile Wuchang bream (Megalobrama amblycephala) and its resistance under ammonia stress, juvenile Wuchang bream were randomly assigned into four groups: a control group fed basal diets and three treatment groups fed basal diets supplemented with 0.50 mg/kg SY, 50 mg/kg TPs and a combination of 0.50 mg/kg SY and 50 mg/kg TPs, respectively. After 60 days of feeding, growth parameters of Wuchang bream were measured along with serum hormones and the transcription of growth axis-related genes. Then fish were exposed to ammonia stress of 22.5 mg/L total ammonia nitrogen. Hepatic oxidative damage parameters, antioxidant responses and ultrastructure were evaluated before ammonia exposure (0 h) and at 3, 6, 12, 24, and 48 h after ammonia exposure. Results show that before ammonia exposure, the growth parameters, serum GH and IGF-1 levels as well as the growth axis-related gene expression (gh, ghr2 and igf-1) for the SY and combination groups were higher than those determined for the fish on the control diet. In contrast, the administration of TP alone didn’t have significant effects on the growth parameters and growth-related hormones. After ammonia exposure, compared with the control, remarkable increases in the activity and mRNA expression of hepatic antioxidant enzymes (glutathione peroxidase and catalase superoxide dismutase) in three treatment groups were observed along with decreases of hepatic malondialdehyde and protein carbonylation levels, indicating that the single and combined supplementation of SY and TPs could enhance antioxidant capacity to alleviate oxidative stress and damage by ammonia. Consistent with this finding, alterations of the liver ultrastructure in three treatment groups were less severe and faster recovery than in the control group after ammonia exposure. In conclusion, a basal diet supplemented with the combination of 0.50 mg/kg SY and 50 mg/kg TPs could has very beneficial effects on the whole aspects of the growth and ammonia resistance in Wuchang bream juveniles.

The Ethanol Fraction of White Rose Petal Extract Abrogates Excitotoxicity-Induced Neuronal Damage In Vivo and In Vitro through Inhibition of Oxidative Stress and Proinflammation.

Since oxidative stress and inflammation are involved in seizure-related neurotoxicity, the neuroprotective effect of a white rose (Rosa hybrida) petal extract (WRPE) in mice that are challenged with kainic acid (KA) were examined using behavioral epileptiform seizures as well as biochemical and morphological parameters of oxidative stress and inflammation. WRPE (50–200 mg/kg) was orally administered to male ICR mice for 15 days, and intraperitoneally challenged with KA (30 mg/kg). Seizure activity, lipid peroxidation, inflammatory cytokines, and related enzymes were analyzed in the brain tissue, in addition to the morphological alterations in the hippocampal pyramidal neurons. Separately, antioxidant ingredients in WRPE were analyzed, and antioxidant, anti-inflammatory, and neuroprotective activities of WRPE were investigated in HB1.F3 human neural stem cells (NSCs) to elucidate underlying mechanisms. Total polyphenol and flavonoid contents in WRPE were 303.3 ± 15.3 mg gallic acid equivalent/g extract and 18.5 ± 2.2 mg catechin/g extract, respectively. WRPE exhibited strong radical-scavenging activities and inhibited lipid peroxidation in vitro, and protected glutamate-induced cytotoxicity in NSCs by suppressing inflammatory process. Treatment with WRPE attenuated epileptiform seizure scores to a half level in KA-challenged mice, and decreased hippocampal pyramidal neuronal injury and loss (cresyl violet and DAPI staining) as well as astrocyte activation (GFAP immunostaining). Lipid peroxidation was inhibited, and mRNA expression of antioxidant enzymes (GPx, PHGPx, SOD1, and SOD2) were recovered in the brain tissues. Inflammatory parameters (cytokines and enzymes) including NF-kB, IL-1β, TNF-α, IL-6, HMGB1, TGF-β, iNOS, COX2, and GFAP mRNAs and proteins were also down-regulated by WRPE treatment. Taken together, the results indicate that WRPE could attenuate KA-induced brain injury through antioxidative and anti-inflammatory activities.

Enhanced oxidative stress in smoking and ex-smoking severe asthma in the U-BIOPRED cohort.

Oxidative stress is believed to be a major driver of inflammation in smoking asthmatics. The U-BIOPRED project recruited a cohort of Severe Asthma smokers/ex-smokers (SAs/ex) and non-smokers (SAn) with extensive clinical and biomarker information enabling characterization of these subjects. We investigated oxidative stress in severe asthma subjects by analysing urinary 8-iso-PGF2α and the mRNA-expression of the main pro-oxidant (NOX2; NOSs) and anti-oxidant (SODs; CAT; GPX1) enzymes in the airways of SAs/ex and SAn. All the severe asthma U-BIOPRED subjects were further divided into current smokers with severe asthma (CSA), ex-smokers with severe asthma (ESA) and non-smokers with severe asthma (NSA) to deepen the effect of active smoking. Clinical data, urine and sputum were obtained from severe asthma subjects. A bronchoscopy to obtain bronchial biopsy and brushing was performed in a subset of subjects. The main clinical data were analysed for each subset of subjects (urine-8-iso-PGF2α; IS-transcriptomics; BB-transcriptomics; BBr-transcriptomics). Urinary 8-iso-PGF2α was quantified using mass spectrometry. Sputum, bronchial biopsy and bronchial brushing were processed for mRNA expression microarray analysis. Urinary 8-iso-PGF2α was increased in SAs/ex, median (IQR) = 31.7 (24.5–44.7) ng/mmol creatinine, compared to SAn, median (IQR) = 26.6 (19.6–36.6) ng/mmol creatinine (p< 0.001), and in CSA, median (IQR) = 34.25 (24.4–47.7), vs. ESA, median (IQR) = 29.4 (22.3–40.5), and NSA, median (IQR) = 26.5 (19.6–16.6) ng/mmol creatinine (p = 0.004). Sputum mRNA expression of NOX2 was increased in SAs/ex compared to SAn (probe sets 203922_PM_s_at fold-change = 1.05 p = 0.006; 203923_PM_s_at fold-change = 1.06, p = 0.003; 233538_PM_s_at fold-change = 1.06, p = 0.014). The mRNA expression of antioxidant enzymes were similar between the two severe asthma cohorts in all airway samples. NOS2 mRNA expression was decreased in bronchial brushing of SAs/ex compared to SAn (fold-change = -1.10; p = 0.029). NOS2 mRNA expression in bronchial brushing correlated with FeNO (Kendal’s Tau = 0.535; p< 0.001). From clinical and inflammatory analysis, FeNO was lower in CSA than in ESA in all the analysed subject subsets (p< 0.01) indicating an effect of active smoking. Results about FeNO suggest its clinical limitation, as inflammation biomarker, in severe asthma active smokers. These data provide evidence of greater systemic oxidative stress in severe asthma smokers as reflected by a significant changes of NOX2 mRNA expression in the airways, together with elevated urinary 8-iso-PGF2α in the smokers/ex-smokers group.Trial registration ClinicalTrials.gov—Identifier: NCT01976767

Inhibitory effects of Orostachys malacophyllus var. iwarenge extracts on reactive oxygen species production and lipid accumulation during 3T3-L1 adipocyte differentiation.

Orostachys malacophyllus var. iwarenge was extracted with water, 30 and 70% ethyl alcohol. The ethyl alcohol extracts showed higher total phenol contents and greater antioxidant effects than the water extract. Treatment with the 70% alcohol extract inhibited reactive oxygen species (ROS) production and lipid accumulation during 3T3-L1 adipogenesis. Furthermore, the 70% extract inhibited the mRNA and protein expressions of the pro-oxidant enzyme NADPH oxidase 4 and of the NADPH-producing enzyme glucose-6-phosphate dehydrogenase. The mRNA and protein expressions of antioxidant enzymes, such as copper-zinc superoxide dismutase and manganese superoxide dismutase increased in cells treated with the 70% alcohol extract. In addition, this extract suppressed the mRNA and protein levels of adipogenic transcription factors and of their marker genes. These results indicate that O. malacophyllus extracts inhibit lipid accumulation and ROS production by controlling adipogenic factors and pro-/anti-oxidant enzyme responses.

Effects of Coriandrum Sativum Extract and Simvastatin in Isopreterenol Induced Heart Failure in Rats

Abstract Heart failure is a syndrome, caused due to structural and functional cardiac abnormalities, characterized by changes in the hemodynamic and neurohumoral mechanisms. It is becoming a major health burden worldwide. More effective therapies are desperately needed. Coriandrum sativum (C. sativum), a traditional spice crop has been known to possess many biological and medicinal properties. The present study was designed to investigate the cardioprotective efficacy of C. sativum in rat model of isoproterenol induced heart failure. Heart failure was produced by injecting isoproterenol subcutaneously (85 mg/kg twice at an interval of 24 h). Oral efficacy of seed extract was assessed on hemodynamic profile, antioxidant enzyme activities, lipid peroxidation, lipid profile, atherogenic indices, mRNA and protein expression of endothelin receptors (ETA and ETB) and histopathology. Treatment of heart failure rats with C. sativum orally (1g/kg b.wt) improved the altered hemodynamics, restored the cardiac antioxidant enzymes armory, attenuated oxidative stress, improved lipid profile, lowered atherogenic indices, decreased the levels of ETA and ETB receptor mRNA and protein, and restored the cardiac morphology. In conclusion, our results suggest C. sativum to be a cardioprotective agent in heart failure, possibly by the virtue of its ability to alleviate oxidative stress, improve lipid profile and endothelial dysfunction.

An in vivo analysis of Cr6+ induced biochemical, genotoxicological and transcriptional profiling of genes related to oxidative stress, DNA damage and apoptosis in liver of fish, Channa punctatus (Bloch, 1793)

Present study was designed to assess the hexavalent chromium (Cr6+) mediated oxidative stress that induces DNA damage and apoptosis in adult fish, Channa punctatus (35 ± 3.0 g; 14.5 ± 1.0 cm; Actinopterygii). Fishes were maintained in three groups for 15, 30 and 45 d of exposure periods. They were treated with 5% (Group T1) and 10% (Group T2) of 96 h-LC50 of chromium trioxide (Cr6+). Controls were run for the similar duration. A significant (p < 0.05) increment in the activities of antioxidant enzymes, SOD and CAT in liver tissues of the exposed fish evinces the persistence of oxidative stress. A significant (p < 0.05) increase in induction of micronuclei (MN) coupled with transcriptional responses of target genes related to antioxidant enzymes, DNA damage and apoptosis (sod, cat, gsr, nox-1, p53, bax, bcl-2, apaf-1 and casp3a) establishes the impact of oxidative stress due to in vivo, Cr6+ accumulation in liver as compared to control (0 mg/L), in a dose and exposure-dependent manner. Initially, the increased level of reactive oxygen species (ROS) in liver coincided with that of enhanced mRNA expression of antioxidant enzymes, sod, cat, gsr and nox-1 but, later, the overproduction of ROS, after 45 d of exposure of Cr6+, resulted in a significant (p < 0.05) up-regulation of p53. Our findings also unveil that the up-regulation of bax, apaf-1 and casp3a and down-regulation of bcl-2 are associated with Cr6+-induced oxidative stress mediated-apoptosis in liver of test fish. Aforesaid molecular markers can, thus, be efficiently utilized for bio-monitoring of aquatic regimes and conservation of fish biodiversity.

Dopaminergic dysregulation and impaired associative learning behavior in zebrafish during chronic dietary exposure to selenium

A growing body of evidence indicates that exposure to selenium (Se) can cause neurotoxicity, and this can occur because of its interference with several neurotransmitter systems in humans and animals. Dopamine is a critical modulator of a variety of brain functions and a prime target for environmental neurotoxicants. However, effects of environmentally relevant concentrations of Se on dopaminergic system and its neurobehavioral effects are still largely unknown. For this purpose, we exposed zebrafish, a model organism, to different concentrations of dietary l-selenomethionine (control, 3.5, 11.1, 27.4, and 63.4 μg Se/g dry weight) for a period of 60 days. Cognitive performance of fish was evaluated using a plus maze associative learning paradigm. Oxidative stress, as the main driver of Se neurotoxicity, was assessed by measuring the ratio of reduced to oxidized glutathione (GSH:GSSG), lipid peroxidation (LPO) levels, and mRNA expression of several antioxidant enzymes in the zebrafish brain. Dopamine levels in the brain and the expression of genes involved in dopamine synthesis, storage, reuptake, metabolism, and receptor activation were examined. Moreover, transcription of several synaptic plasticity-related immediate-early and late response genes was determined. Overall, fish fed with the two highest concentrations of dietary Se displayed impaired associative learning. Se exposure also induced oxidative stress in the zebrafish brain, as indicated by a reduction in GSH:GSSG ratio, increased LPO levels, and up-regulation of antioxidant genes in fish treated with the two highest concentrations of Se. An increase in brain dopamine levels associated with altered expression of dopaminergic cell markers was evident in different treatment groups. Moreover, Se exposure led to the down-regulation of immediate-early and late response genes in fish that exhibiting learning impairment. Taken together, the results of this study imply that the induction of oxidative stress and dysregulation of dopaminergic neurotransmission may underlie Se-induced impairment of associative learning in zebrafish.

Effects of dietary lipid-coated zinc on the antioxidant defense system in the small intestine and liver of piglets

The purpose of the study was to investigate the effects of lipid-coated ZnO (LCZ) and the level of LCZ compared with ordinary zinc oxide (ZnO) on antioxidant defense system in the intestine and liver of piglets. A total of forty piglets (n=8) were fed a diet supplemented with 100 ppm Zn with ZnO (ZnO-1), 2,500 ppm Zn with ZnO (ZnO-2), 100 ppm Zn as LCZ (LCZ-1), 200 ppm Zn as LCZ (LCZ-2), or 400 ppm Zn as LCZ (LCZ-3) for 14-d, respectively. The LCZ-3 group resulted in higher (P<0.05) mRNA expressions and activities of CuZn-superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and glutathione S-transferase (GST) in jejunal mucosa compared with the ZnO-1 and LCZ-1 groups, while no difference was observed in the mRNA level of antioxidant genes between the ZnO-1 and ZnO-2 groups. Within the LCZ groups, the LCZ level linearly and quadratically (P<0.01) increased antioxidant enzymes in the jejunum. The maximum response of jejunal antioxidant enzymes to Zn supplementation was achieved by 400 ppm of LCZ. Hepatic mRNA expression of antioxidant enzymes was unaffected by Zn source and level, while hepatic SOD and GST activities were greater (P<0.05) in the LCZ-3 group than in the ZnO-1 group. No difference was observed in lipid peroxidation of the jejunum and liver and the total antioxidant power of plasma among groups. In conclusion, a supplementation with 400 ppm of LCZ resulted in a maximum increase in antioxidant enzymes, indicating that LCZ may affect antioxidant defense system more profoundly than ZnO.

Diphlorethohydroxycarmalol Attenuates Methylglyoxal-Induced Oxidative Stress and Advanced Glycation End Product Formation in Human Kidney Cells.

Diabetic nephropathy is the leading cause of end-stage renal disease in patients with diabetes mellitus. Oxidative stress has been shown to play an important role in pathogeneses of renal damage in diabetic patients. Here, we investigated the protective effect of diphlorethohydroxycarmalol (DPHC), which is a polyphenol isolated from an edible seaweed, Ishige okamurae, on methylglyoxal-induced oxidative stress in HEK cells, a human embryonic kidney cell line. DPHC treatment inhibited methylglyoxal- (MGO-) induced cytotoxicity and ROS production. DPHC activated the Nrf2 transcription factor and increased the mRNA expression of antioxidant and detoxification enzymes, consequently reducing MGO-induced advanced glycation end product formation. In addition, DPHC increased glyoxalase-1 mRNA expression and attenuated MGO-induced advanced glycation end product formation in HEK cells. These results suggest that DPHC possesses a protective activity against MGO-induced cytotoxicity in human kidney cells by preventing oxidative stress and advanced glycation end product formation. Therefore, it could be used as a potential therapeutic agent for the prevention of diabetic nephropathy.

Antioxidant Activity and Upregulation of Antioxidant Enzymes of Phenolic Glycosides from Aquilaria crassna Leaves

The leaves of Aquilaria crassna Pierre ex Lecomte (Thymelaeaceae) have been used in the traditional medicine and consumed as a health-promoting tea in several Asian countries. This study investigated the antioxidant activity of three major bioactive constituents of A. crassna leaves, genkwanin 5- O-β-primeveroside (1), iriflophenone 3,5- C-β-D-diglucoside (2) and iriflophenone 3- C-β-D-glucoside (3) using DPPH and superoxide scavenging assays, as well as their effects on induction of mRNA and protein expressions of antioxidant enzymes in HEK-293 cells. The benzophenone glycoside 3 exhibited significant scavenging activity against both types of free radicals and increased the mRNA expression of antioxidant enzymes such as glutathione peroxidase-1, glutathione reductase and heme oxygenase-1 in HEK-293 cells. In addition, all three compounds also increased the protein expression of glutathione peroxidase-1. These findings revealed the effects of these compounds at cellular level, and might be useful for the development of A. crassna leaves as supplements for prevention of oxidative stress.

Protective Effect of Ginger (Zingiber officinale Roscoe) Extract against Oxidative Stress and Mitochondrial Apoptosis Induced by Interleukin-1β in Cultured Chondrocytes

Aims: The protective effects of ginger (Zingiber officinale Roscoe) extract on IL-1β-mediated oxidative stress and mitochondrial apoptosis were investigated in C28I2 human chondrocytes. Methods: The effects of various concentrations of ginger extract on C28I2 human chondrocyte viability were evaluated in order to obtain noncytotoxic concentrations of the drug by methylthiotetrazole assay. The cells were pretreated with 5 and 25 μg/mL ginger extract for 24 h, followed by incubation with IL-1β (10 ng/mL) for 24 h. The effects of ginger extract on IL-1β-induced intracellular reactive oxygen species (ROS) production and lipid peroxidation were examined. The mRNA expressions of antioxidant enzymes including catalase, superoxide dismutase-1, glutathione peroxidase-1, glutathione peroxidase-3, and glutathione peroxidase-4 were evaluated by reverse transcription polymerase chain reaction. The protein expressions of Bax, Bcl-2, and caspase-3 were analyzed by Western blotting. Results: No cytotoxicity was observed at any concentration of ginger extract in C28I2 cells. Ginger extract pretreatment remarkably increased the gene expression of antioxidant enzymes and reduced the IL-1β-induced elevation of ROS, lipid peroxidation, the Bax/Bcl-2 ratio, and caspase-3 activity. Conclusions: Ginger extract could considerably reduce IL-1β-induced oxidative stress and consequent mitochondrial apoptosis as the major mechanisms of chondrocyte cell death. These beneficial effects of ginger extract may be due to its antioxidant properties. It may be considered as a natural herbal product to prevent OA-induced cartilage destruction in the clinical setting.

Effect of different wavelengths of light on the antioxidant and immunity status of juvenile rock bream, Oplegnathus fasciatus, exposed to thermal stress

We investigated the effect of light wavelengths on antioxidant and immunity parameters in juvenile rock bream, Oplegnathus fasciatus, exposed to thermal stress (25 and 30°C). We exposed the fish to light emitting diodes (LEDs) emitting green (520 nm) and red light (630 nm) of 0.25 and 0.5 W/m2 intensity, and measured the activity, and mRNA and protein expression levels of the antioxidant enzymes, superoxide dismutase, catalase, and glutathione peroxidase. We also determined the levels of plasma hydrogen peroxide (H2O2), melatonin, and lysozyme. Furthermore, the mRNA and protein levels of caspase-3 were measured and terminal transferase dUTP nick end labeling (TUNEL) assays were performed. We observed that mRNA expression and activities of antioxidant enzymes and plasma H2O2 levels were significantly higher after exposure to high temperatures. However, increases in these parameters were significantly lower after exposure to green LED light. The plasma melatonin and lysozyme levels were significantly lower in the different groups after exposure to high temperatures; however, in groups exposed to green LED light, their levels were significantly higher than those in the control group. The expression pattern of caspase-3 mRNA was similar to that of H2O2. The TUNEL assay showed that apoptosis was markedly higher at higher water temperatures than that at 20°C. These results indicate that high water temperatures induce oxidative stress and decrease the immunity in juvenile rock bream but green LED light inhibits the rise in oxidative stress and combats the decrease in immunity and should, thus, be useful in the culture of rock bream.