Induction Of Superoxide Dismutase Research Articles

Hepatoprotective properties of Curcuma longa L. extract in bleomycin-induced chronic hepatotoxicity.

Curcuma longa L. (CLL) extract has previously been reported to alleviate liver damage. The current study examined the antioxidant activity of CLL by which the extract protects the liver against bleomycin (BLM)-induced hepatotoxicity in mice. The hypothesis was that CLL extract would protect the liver by reducing oxidative stress (induced superoxide dismutase (SOD) and catalase (CAT) activity), inhibiting lipid peroxidation, lowering biochemical parameters, and decreasing ROS production. Hepatic toxicity was induced by intraperitoneal injection of mice once daily with BLM (0.069 U/mL; 0.29 U/kg bw.) for a period of 4 weeks. The CLL was administered once a day for 4 weeks, 2 h prior at dose (40 mg/mL; 0.187 mg/kg/day). CLL extract significantly protected the liver, it decreased plasma bilirubin (BL) and gamma glutamyl transpeptidase (GGT), and it reduced lipid peroxidation levels. BLM intoxication produced oxidative stress, in which the antioxidant system functioned incorrectly and ROS production significantly increased. The CLL extract provided significant hepatic protection against BLM toxicity by improving SOD, CAT (p < 0.05), and MDA levels and decreasing ROS in the group receiving BLM (p < 0.05), leading to reduced membrane lipid peroxidation. Throughout this study, the CLL extract facilitated recovery from BLM-induced hepatic injury by suppressing oxidative stress. Therefore, the CLL extract has the potential to serve as an antioxidant compound to treat chronic hepatotoxicity.

Cardioprotective Effect of Rhapontigenin in Isoproterenol-Induced Myocardial Infarction in a Rat Model

Background/Aims: Rhapontigenin (RPG) is a stilben derivative and is known to bear several effects such as antiallergic, anticoagulative, hypoglycemic, antiangiogenic, and purgative. The investigation was conducted to evaluate the cardioprotective efficacy of RPG in rats having acute myocardial infarction (MI) induced by isoproterenol (ISO). Methods: Animals were divided into 6 groups: group I (control group), group II (ISO-treated), group III (1.0 mg/kg/day RPG and ISO-treated), group IV (2.5 mg/kg/day RPG and ISO-treated), group V (5.0 mg/kg/day RPG and ISO-treated), and group VI (treated with RPG 5.0 mg/kg/day). Various cardiac stress markers, including infarct size and heart/body weight index, were investigated in animals with ISO-induced MI, such as inducible nitric oxide synthase (iNOS), creatinine kinase (CK), lactate dehydrogenase (LD), cardiac troponin-T (CTT), superoxide dismutase (SOD), and malondialdehyde. INOS, p38, caspase-3, and connexin 43 expressions were analyzed in animals. Inflammatory mediators, tissue necrosis factor-α (TNF-α) and interleukin-6 (IL-6), were detected in serum of experimental animals. Results: Group I animals indicated normal levels of biochemical parameters, whereas group II animals indicated high levels of these parameters and successful induction of MI. Pretreatment of animal groups III, IV, and V with RPG revealed amelioration of infarct size, heart/body weight index, CK, LD, CTT in rats, whereas group VI animals were treated only with RPG (5.0 mg/kg/day) and not with ISO. Levels of TNF-α, IL-6, MD, SOD, p38, and iNOS expressions were significantly downregulated by RPG administration (5.0 mg/kg/day). Conclusion: RPG ameliorates MI caused by ISO in rats and provides cardioprotective effect, via anti-inflammatory, antioxidant, and antiapoptotic effect.

Mitochondrial superoxide disrupts the metabolic and epigenetic landscape of CD4+ and CD8+ T-lymphocytes

While the role of mitochondrial metabolism in controlling T-lymphocyte activation and function is becoming more clear, the specifics of how mitochondrial redox signaling contributes to T-lymphocyte regulation remains elusive. Here, we examined the global effects of elevated mitochondrial superoxide (O2-) on T-lymphocyte activation using a novel model of inducible manganese superoxide dismutase (MnSOD) knock-out. Loss of MnSOD led to specific increases in mitochondrial O2- with no evident changes in hydrogen peroxide (H2O2), peroxynitrite (ONOO−), or copper/zinc superoxide dismutase (CuZnSOD) levels. Unexpectedly, both mitochondrial and glycolytic metabolism showed significant reductions in baseline, maximal capacities, and ATP production with increased mitochondrial O2- levels. MnSOD knock-out T-lymphocytes demonstrated aberrant activation including widespread dysregulation in cytokine production and increased cellular apoptosis. Interestingly, an elevated proliferative signature defined by significant upregulation of cell cycle regulatory genes was also evident in MnSOD knock-out T-lymphocytes, but these cells did not show accelerated proliferative rates. Global disruption in T-lymphocyte DNA methylation and hydroxymethylation was also observed with increased mitochondrial O2-, which was correlated to alterations in intracellular metabolite pools linked to the methionine cycle. Together, these results demonstrate a mitochondrial redox and metabolic couple that when disrupted may alter cellular processes necessary for proper T-lymphocyte activation.

Antioxidant response to salinity stress in freshwater and marine Bangia (Bangiales, Rhodophyta)

Bangia is an ancient and genetically diverse red algae genus, containing one freshwater species. It has been reported that freshwater Bangia acclimates seawater and marine Bangia survives freshwater after gradual adaptation or one to several steps transfer. However, little is known about the acclimation mechanism. The present study revealed that marine Bangia tolerated moderate hyposalinity and freshwater Bangia endured seawater as indicated by the maximum quantum yield of PSII (Fv/Fm). Little reduction of Fv/Fm occurred in 100% seawater treated freshwater Bangia and there was no significant difference of Fv/Fm under different hypersalinity on the 5th day. The O2.− levels were lower than control while accumulation of H2O2 was observed in the hypersalinity-treated freshwater Bangia and hyposalinity-treated marine Bangia. There was a correlation between O2.− and superoxide dismutase induction, resulting in effective removal of O2.−. Mono- to multi-phasic induction of peroxidase occurred in hyposaline stressed marine Bangia and induction of catalase was present in hypersaline stressed freshwater Bangia. The Fv/Fm reduction was the highest in 100% freshwater-treated marine Bangia, while neither peroxidase nor catalase activity was enhanced. The glutathione reductase activities exhibited triphasic induction in 100% freshwater-treated marine Bangia and 100% seawater-treated freshwater Bangia, indicating that glutathione reductase played important roles under highly saline stress. In sum, the antioxidant enzymes activities were peroxidase > superoxide dismutase > glutathione reductase > catalase. The H2O2 and antioxidases was less induced and Fv/Fm was less reduced in seawater-stressed freshwater Bangia than in freshwater-stressed marine Bangia in most cases. The results suggested a higher capacity of freshwater Bangia endurance to seawater than marine Bangia endurance to freshwater.

Astaxanthin enhances the longevity of Saccharomyces cerevisiae by decreasing oxidative stress and apoptosis.

The budding yeast, Saccharomyces cerevisiae, is an efficient model for studying oxidative stress, programmed cell death and aging. The present study was carried out to investigate antioxidant, the anti-apoptotic and anti-aging activity of a natural compound, astaxanthin, in S. cerevisiae model. The survivability of yeast antioxidant-deficient strains (sod1Δ, sod2Δ, cta1Δ, ctt1Δ and tsa1Δ) increased by 20%-40% when cells were pre-treated with astaxanthin, compared to hydrogen peroxide alone, as demonstrated in spot and colony forming unit assays. Reduced reactive oxygen species (ROS) levels, increased glutathione, decreased lipid peroxidation and induced superoxide dismutase activity in astaxanthin-treated cells indicate that astaxanthin protected the cells from oxidative-stress-induced cell death. In addition, astaxanthin protected anti-apoptotic-deficient strains (pep4Δ and fis1Δ) against acetic acid and hydrogen peroxide-induced cell death that suggests anti-apoptotic property of astaxanthin, and it was further confirmed by acridine orange/ethidium bromide, annexin V and 4',6-diamidino-2-phenylindole staining. The yeast chronological lifespan assay results showed that astaxanthin extends the lifespan of antioxidant-deficient strains by scavenging ROS, and anti-apoptotic-deficient mutants by protecting from apoptotic cell death compared to their respective untreated cells and wild type. Our results suggest that astaxanthin enhances the longevity of yeast S. cerevisiae by reducing oxidative stress and apoptosis.

Copper accumulation and toxicity in earthworms exposed to CuO nanomaterials: Effects of particle coating and soil ageing

Engineered nanomaterials (ENMs) may be functionalised with a surface coating to enhance their properties, but the ecotoxicity of the coatings and how hazard changes with ageing in soil is poorly understood. This study determined the toxic effect of CuO ENMs with different chemical coatings on the earthworm (Eisenia fetida) in fresh soil, and then after one year in aged soil. In both experiments, earthworms were exposed for 14 days to the CuO materials at nominal concentrations of 200 and 1000 mg Cu kg−1 dry weight and compared to CuSO4. In the fresh soil experiment, CuO-COOH was found to be the most acutely toxic of the nanomaterials (survival, 20 ± 50%), with tenfold increase of total Cu in the earthworms compared to controls. Sodium pump activity was reduced in most CuO ENM treatments, although not in the CuSO4 control. There was no evidence of glutathione depletion or the induction of superoxide dismutase (SOD) activity in any treatment. Histology showed a mild hypoplasia of mucous cells in the epidermis with some nanomaterials. In the aged soil, the CuO-NH4+ was the most acutely toxic ENM (survival 45 ± 3%) and Cu accumulation was lower in the earthworms than in the fresh soil study. Depletion of tissue Mn and Zn concentrations were seen in earthworms in aged soil, while no significant effects on sodium pump or total glutathione were observed. Overall, the study showed some coating-dependent differences in ENM toxicity to earthworms which also changed after a year of ageing the soil.

Gold Octahedra nanoparticles (Au_0.03 and Au_0.045): Synthesis and impact on marine clams Ruditapes decussatus

The increased use of gold nanoparticles (AuNPs) in several applications has led to a rise in concerns about their potential toxicity to aquatic organisms. In addition, toxicity of nanoparticles to aquatic organisms is related to their physical and chemical properties. In the present study, we synthesize two forms of gold octahedra nanoparticles (Au_0.03 and Au_0.045) in 1.3-propandiol with polyvinyl-pyrrolidone K30 (PVPK30) as capping agent using polyol process. Shape, size and optical properties of the particles could be tuned by changing the molar ratio of PVP K30 to metal salts. The anisotropy in nanoparticles shape shows strong localized surface plasmon resonance (SPR) in the near infrared region of the electromagnetic spectrum.Environmental impact of Oct-AuNPs was determined in the marine bivalve, Ruditapes decussatus exposed to different concentrations of Au_0.03 and Au_0.045. The dynamic light scattering showed the stability and resistance of Au_0.03 and Au_0.045 in the natural seawater. No significant modification in vg-like proteins, MDA level and enzymatic activities were observed in treated clams with Au_0.03 even at high concentration. In contrast, Au_0.045 induced superoxide dismutase (SOD), catalase (CAT), glutathione transferase (GST) activities, in a concentration dependent manner indicating defense against oxidative stress. Enhanced lipid peroxidation represented by malondialdehyde content confirmed oxidative stress of Au_0.045 at high concentration.These results highlight the importance of the physical form of nanomaterials on their interactions with marine organisms and provide a useful guideline for future use of Oct-AuNPs. In addition, Vitellogenin is shown not to be an appropriate biomarker for Oct-AuNPs contamination even at high concentration. We further show that Oct-AuNPs exhibit an important antioxidant response without inducing estrogenic disruption.

Radish (Raphanus sativus L.) Cultivar‐Specific Response to O3: Patterns of Biochemical and Plant Growth Characteristics

The sensitivity of four radish (Raphanus sativus L.) cultivars, Baladey “B,” Cherry Belle “CB,” Prinz Rotin “PR,” and Scarlet Globe “SG” to 80 nL L−1 ozone is assessed in fumigation chambers. O3 visible injury symptoms appears as brown spots to chlorotic areas, but the response is cultivar‐specific. O3 induces higher content of H2O2 and lipid peroxidation (it is estimated as malondialdehyde (MDA) content), leading to drastic visible injury symptoms in B compared to the other cultivars. Root and shoot dry weights, Chlorophyll a, net photosynthetic rates, and chlorophyll fluorescence are reduced in B to a greater extent than the other cultivars. On the other hand, stomatal conductance increased in B and CB (+52 and +24%, respectively) due to O3‐exposure, while it was decreased by 35% in PR and SG. Exposure to O3 generates oxidative stress leading to stimulation of antioxidative defense systems. SG shows the highest induction of catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR), while B had the lowest activities of these antioxidative enzymes, but had the highest H2O2 and MDA content. The higher accumulation of H2O2, poor induction of antioxidative enzymes, and increased stomatal conductance led to severe visible injury and drastic inhibition in photosynthetic rates and growth in B than other cultivars depicting its higher sensitivity toward O3. Therefore, it can be used as a bioindicator for O3 pollution worldwide.

Antioxidant enzymes and reactive oxygen species level of the Achromobacter xylosoxidans bacteria during hydrocarbons biotransformation.

The level of catalase and superoxide dismutase induction, as well as generation of superoxide anion radical in cells and accumulation of hydrogen peroxide in the culture medium were researched in three strains of oil-degrading bacteria Achromobacter xylosoxidans at cultivation in rich nutrient medium and in the media with hydrocarbons as the only source of carbon. The effects of pentane, decane, hexadecane, cyclohexane, benzene, naphthalene and diesel fuel were evaluated. It was determined that in the microbial cell on media with hydrocarbons, the generation of superoxide anion radical increases, accumulation of hydrogen peroxide and induction of superoxide dismutase synthesis occur, and catalase activity is reduced. Oxidative stress in the cells of A. xylosoxidans was caused by biotransformation of all the studied hydrocarbons. The most pronounced effect was observed at incubation of bacteria with cyclohexane, pentane, diesel fuel, benzene and naphthalene.

Melatonin levels in human diabetic dental pulp tissue and its effects on dental pulp cells under hyperglycaemic conditions.

To investigate melatonin (MEL) levels in human dental pulp tissue (hDP) in type 2 diabetic (T2D) participants and the underlying molecular mechanisms of its effects in human dental pulp cells (hDPCs) under hyperglycaemia. The study included 16 healthy and 16 T2D participants who underwent vital pulp extirpation for hDP and four healthy participants undergoing third molar extraction for hDPCs analyses. MTT and NRU were used as tests for cytotoxicity. The pulp tissue levels of MEL, inducible NO synthase (iNOS) and superoxide dismutase (SOD) activity, as well as iNOS, histone acetyltransferase p300 (p300) and SOD activity levels in hDPCs incubated with MEL (0.1 and 1.0mmolL-1 ) under normoglycaemia and hyperglycaemia were measured by enzyme-linked immunosorbent assay. Comparisons between the two groups were made by unpaired t-tests or Mann-Whitney test whilst the chi-square test was used for dichotomous variables. To compare more groups, the Kruskal-Wallis test with Dunn's multiple comparison was used, whilst Spearman correlation was used to assess association between two variables. Melatonin was decreased (124.30±21.6 vs. 240.0±19.1 pgmL-1 , P<0.01), whilst iNOS levels increased (0.92±0.08 vs. 0.32±0.09ngmL-1 , P<0.01) in hDP from T2D compared to nondiabetic participants. In hDPCs, MEL (0.1 and 1.0mmolL-1 ) had no cytotoxicity. Incubation with 1.0mmolL-1 of MEL (24h) decreased hyperglycaemia-induced increases of iNOS (0.34±0.01ngmL-1 vs. 0.40±0.01ngmL-1 , P<0.01) and p300 (11.59±0.58ngmL-1 vs. 16.12±0.39ngmL-1 , P<0.01), and also, increased SOD activity (87.11±3.10% vs. 68.56±3.77%, P<0.01) to the levels comparable to the normoglycaemic; iNOS and p300 protein expression levels showed strong positive correlation under hyperglycaemia (Spearman r=0.8242, P<0.001). Type 2 diabetic participants had decreased MEL in hDP. At pharmacological concentrations, MEL is not cytotoxic for hDPCs and normalizes iNOS and SOD activity levels in hyperglyceamic hDPCs suggesting its antioxidant and protective effects in human dental pulp tissue under hyperglycaemia.

Oxidative stress in osteoarthritis and antioxidant effect of polysaccharide from angelica sinensis

This study aimed to investigate the oxidative stress in human osteoarthritis (OA) chondrocytes and the antioxidant effect of angelica sinensis polysaccharide (ASP) on it. Human OA chondrocytes and human normal chondrocytes induced by hydrogen peroxide (H2O2) alone or treated with ASP were cultured, then they were measured with cell viability, levels of reactive oxygen species (ROS), nitric oxide (NO) and malondialdehyde (MDA) production, activities of inducible nitric oxide synthase (iNOS), superoxide dismutase (SOD) and catalase (CAT), expression of related genes, such as collagen type II (Col2a1), Aggrecan, iNOS, SOD, CAT and peroxisome proliferator-activated receptor gamma (PPARγ). We found that the production of ROS, NO, and MDA and the activity of iNOS, SOD and CAT were significantly increased in OA chondrocytes compared with human normal chondrocytes. When treated with H2O2, human chondrocytes exhibited acute oxidative stress injure, which was similar to OA chondrocytes. Pretreatment with ASP before H2O2 alleviated oxidative stress and protected human chondrocytes. The activity of PPARγ was decreased in OA chondrocytes and increased when treated with ASP. In conclusion, oxidative stress is an important pathogenesis of OA, and ASP inhibits H2O2-mediated injury in human chondrocytes. Our data also suggest that PPARγ participates in oxidation and anti-oxidation of OA.

Possible protective effect of statins against renal ischemic‐reperfusion injury in diabetic rats: a biochemical and histochemical study

BackgroundAcute renal failure may complicate ischemic‐reperfusion injury (IRI) due to the production of reactive oxygen species. Atorvastatin (ATO) is well known for its antioxidant and antiinflammatory effects. It may be possible to protect against acute renal failure by preventing IRI.Aim of studyThe current study has been carried out to investigate the protective effect of ATO against renal IRI in diabetic rats.MethodsThe current study used 2 groups of rats, A and B, (18 rats each). Group A (non‐diabetic) was subdivided into: Group A1 (non‐diabetic sham), Group A2 (non‐diabetic IRI), Group A3 (non‐diabetic ATO‐treated + IRI). Group B (diabetic) was subdivided into: Group B1 (diabetic sham), Group B2 (diabetic IRI), and Group B3 (diabetic ATO‐treated + IRI). All rats were subjected to renal ischemia, bilaterally, for 45 minutes, followed by reperfusion for 24 hours. Rats in Groups A3 and B3 were injected with single doses of ATO (10 mg/kg), intraperitoneal, half hour before induction of renal ischemia. Serum kidney functions including blood urea nitrogen (BUN) and creatinine, and oxidative stress markers in renal tissue homogenate, including malondialdehyde (MDA), inducible nitric oxide synthase (iNOS), superoxide dismutase (SOD), and glutathione reductase (GR), were studied to measure renal IRI.ResultsGroups A2 and B2 revealed marked increase in BUN, creatinine, MDA, and iNOS and a decrease in SOD and GR. Corresponding results in Groups A3 and B3 suggested improvement in both, the kidney function tests and the oxidative stress markers. This improvement was more significant in Group A3 than Group B3. Study data were analyzed using SPSS and data were described as mean ± standard deviation (SD). Comparisons were performed using one‐way analysis of variance. Differences between mean values were assessed using a t test. A P&lt;.05 was considered statistically significant.ConclusionATO can improve renal IRI, both, in non‐diabetic and diabetic rats, however, its protective effect was less in diabetic rats.Support or Funding InformationThis study was self‐funded.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Neurotoxic Outcomes of Subchronic Manganese Chloride Exposure via Contaminated Water in Adult Male Rats and the Potential Benefits of Ebselen.

The neurological effects of manganese (Mn) exposure on adults consuming contaminated water remain unclear. Accordingly, the current experiment was planned to explore the neurotoxic consequences of subchronic Mn exposure via contaminated water and to examine whether ebselen (Ebs) improved these outcomes. Rats exposed to oral MnCl2 (50mg/kg body weight) for 30 successive days exhibited reduced rearing and ambulation. Furthermore, Mn administration increased brain Mn concentrations and induced superoxide dismutase, catalase, and glutathione depletion. Mn administration also increased lipid peroxidation biomarker levels. Additionally, Mn increased interleukin1-β and prostaglandin E2 levels and altered caspase-3 and Bcl-2 expression. Mn intoxication also induced marked gliosis, numerous vacuolations, and disoriented and pyknotic Purkinje cells as well as marked vascular congestion in brain tissue. Meanwhile, intraperitoneal administration of Ebs (15mg/kg body weight) to Mn-intoxicated rats improved the behavioral performance and oxidative damage as well as inflammatory, apoptotic, and histopathological changes. The above results indicate that Ebs alleviated Mn neurotoxicity via its antioxidant, anti-inflammatory, and anti-apoptotic activities. Therefore, Ebs could represent a promising agent in the prevention of Mn-induced neurotoxicity.

Disulfiram/copper causes ROS levels alteration, cell cycle inhibition, and apoptosis in acute myeloid leukaemia cell lines with modulation in the expression of related genes

The majority of acute myeloid leukaemia (AML) patients will die from their disease or therapy-related complications. There is an inevitable need to improve the survival of AML patients. Previous studies show that disulfiram (DSF), an anti-alcoholism drug with a low toxicity profile, demonstrates anticancer behaviors. Here, we evaluated the cytotoxicity and mechanistic action of DSF on the AML cell lines KG-1, NB4, and U937. The microculture tetrazolium test revealed that DSF alone or in combination with copper (Cu) is highly toxic to the AML cells at concentrations lower than those achievable in the clinical setting, with Cu increasing the DSF-induced inhibition of metabolic activity. Flow cytometric analysis and QRT-PCR indicated that in the two cell lines, NB4 and U-937, DSF/Cu increased reactive oxygen species (ROS) levels in association with the induction of superoxide dismutase 2 (SOD2) expression and suppression of catalase (CAT). In the KG-1 cell line, DSF/Cu reduced the ROS levels in agreement with the induction of CAT expression. The cell cycle and apoptosis assessment by flow cytometry demonstrated that DSF/Cu induced G0/G1 cell cycle arrest and apoptosis. These were associated with the increased expression of FOXO tumor suppressors, decreased expression of the MYC oncogene and the modulation of their known target genes related to the cell cycle and apoptosis. Therefore, DSF/Cu caused the disturbance of the ROS balance, cell cycle arrest and apoptosis in AML cells in coordination with the modulation in expression of their related genes. These results propose the possible use of DSF in AML therapies.

Analysis of differential transcript expression in chickpea during compatible and incompatible interactions with Fusarium oxysporum f. sp. ciceris Race 4.

The present study reports the transcriptome analysis of resistance (WR315) and susceptible (JG62) genotypes of chickpea in response to Fusarium oxysporum f. sp. ciceris (Foc)race 4 using the method of suppression subtractive hybridization. Altogether, 162 chickpea-expressed sequence tags (ESTs) were identified from two libraries and analyzed to catalog eight functional categories. These ESTs could be assembled into 18 contigs and 144 singletons with 10 contigs and 68 singletons from compatible and 8 contigs and 70 singletons from incompatible interaction. The largest category consisted of ESTs which encode for proteins related to hypothetical proteins (22.8%), followed by energy and metabolism (20.3%)-related genes, defense and cell rescue-related genes (17.9%) and signal transduction-related genes (16%). Among them, 17.1 and 18.7% were defense-related genes in compatible and incompatible interaction, respectively. These ESTs mainly includes various putative genes related to oxidative burst, pathogenesis and secondary metabolism. Induction of putative superoxide dismutase, metallothionein, 4-coumarate-CoA ligase, heat shock proteins and cysteine proteases indicated oxidative burst after infection. The ESTs belonged to various functional categories which were directly and indirectly associated with defense signaling pathways. Quantitative and semi-quantitative polymerase chain reaction exhibited differential expression of candidate genes and detected higher levels in incompatible interaction compared to compatible interaction. The present study revealed partial molecular mechanism associated with the resistance in chickpea against Foc, which is the key to design a strategy for incorporation of resistance via either biotechnological means or introgression of resistance genes.

Biochemical changes in mussels submitted to different time periods of air exposure.

Intertidal species face multiple stressors on a daily basis due to their particular habitat. The submergence at high tide in the aquatic environment and emergence at low tide to the aerial environment, associated with a wide variation of abiotic parameters, along with anthropogenic contamination are some of the daily stresses that these organisms are exposed to. With such a dynamic environment, organisms developed strategies that allow them to avoid or tolerate these stressors. Among these species, bivalves are some of the most hypoxia tolerant, being commonly used as abiomonitoring tool due to their capacity to accumulate pollutants from the environment and reflect the imposed toxic impacts. However, when evaluating the response ability of organisms to different stressors under laboratory conditions, it is not common to consider the fact that exposure to tides can act as a confounding factor. The present study assessed the effects of air exposure on the biochemical (metabolic capacity, energy reserves, and oxidative stress related biomarkers) performance of intertidal Mytilus galloprovincialis mussels. Specimens of M. galloprovincialis were submitted once every 24h to different periods of air exposure (3 and 6h) for 14days, under constant air and seawater temperature (19 ± 1°C). Results obtained revealed that air exposure can cause biochemical changes in mussels. The present findings demonstrated that individuals exposed to air induced superoxide dismutase (SOD) and catalase (CAT) activity as mechanisms to withstand the abiotic changes while mobilizing lipid content as the principal source of energy, and increasing protein content possibly as a result of an increase in the number of antioxidant defense enzymes. Moreover, individuals under air exposure suffered higher oxidative damage while showing higher metabolic rate. Results demonstrated that longer periods of air exposure induced moreinjuries, since individuals emerged during 6h presented higher oxidative stress than individuals under 3h of air exposure.

RNA interference in Fasciola gigantica: Establishing and optimization of experimental RNAi in the newly excysted juveniles of the fluke.

Fasciolosis caused by Fasciola gigantica is a neglected tropical disease but a constraint on the growth and productivity of cattle, buffaloes and sheep in the tropical countries of Asia and Africa. Resistance to commonly used anthelmintics in Fasciola has increased the need to search for alternative therapeutic targets. RNA interference is the current tool of choice in the search for such targets in Fasciola. The susceptibility of juvenile Fasciola hepatica to double stranded (ds) RNA induced RNAi has been established but in F. gigantica a single preliminary report on RNAi induced mRNA transcript knockdown is available. Here we optimized conditions for RNAi in the liver fluke F.gigantica targeting six genes including superoxide dismutase (SOD), σ class of glutathione-s-transferase (GST), cathepsin (Cat) L1-D, Cat B1, Cat B2 and Cat B3 that showed robust transcriptional silencing of the targets following exposure of the newly excysted juveniles (NEJs) to long (170–223 nt) dsRNA. Knockdown was shown to be concentration dependent with significant mRNA transcript suppression occurring at 5 ng / μl that showed further suppression with the increase in the dsRNA concentration. The dsRNA induced persistent silencing of the mRNA transcript of SOD and σGST up to 15 days of observation. Delivery of the long dsRNA and siRNA to the newly excysted juveniles by soaking method was found to be efficient by tracking the uptake and diffusion of Cy3 labelled siRNA and long dsRNA in the flukes. Off-target effects of dsRNA trigger on some of the non-target genes were detected in the present investigation on RNAi in F. gigantica. The dsRNA induced superoxide dismutase protein suppression while impact of RNAi on other target proteins was not studied. There is no in vitro culture system for prolonged survival of the F. gigantica and in the present study in vitro maintenance of the NEJs is reported for a period of 3 weeks. The present study is the first attempt on optimization of RNAi protocols in F. gigantica where long dsRNA allowed for an efficient and persistent gene silencing, opening prospects for functional validation of putative vaccine and therapeutic targets in this neglected parasite.

Salinity–induced modulations in the protective defense system and programmed cell death in Nostoc muscorum

To study the biochemical adaptive responses of the blue green algae Nostoc muscorum to the salinity- induced stress they were exposed to various concentrations (5, 10, 15, 20 or 200 mM) of sodium chloride (NaCl). A dose-dependent inhibition of total protein content showed an adverse effect of NaCl on the growth of N. muscorum. Four-day treatment of NaCl (5–20 mM) progressively increased the content of the total peroxide with subsequent increase of the superoxide dismutase (SOD) activity, proline and total phenol content only up to 10 mM NaCl. Higher concentrations of NaCl caused significant decrease in both the enzymatic and non-enzymatic antioxidants. Induction of two polypeptides of ~29.10 and 40.15 kD as well as upregulation of many polypeptides as compared to control indicates the induction of SOD and dehydrin-like proteins, which supports the theory of adaptation against the salt stress. Furthermore, adaptation of N. muscorum to lower concentrations (5–20 mM) of NaCl was also confirmed by no fragmentation of DNA while DNA fragmentation indicating programmed cell death (PCD) could only be seen at 200 mM NaCl for 12 hours. We hypothesized that proline may confer a positive role to combat salinity stress and the same was confirmed by treatment of the test blue green algae with exogenous proline (1 and 10 μM). The results exhibited 16% reduction in the level of total peroxides, which is a well known oxidative stress marker in the 10 μM proline-treated NaCl group as compared to direct exposure to NaCl.

Physiological and molecular responses of resistant and susceptible wheat cultivars to Fusarium graminearum mycotoxin extract

Fusarium graminearum, causing Fusarium head blight (FHB), is one of the most important diseases on cereals worldwide leading to a reduction in both grain yield and quality. Currently, there is limited knowledge about the physiological and molecular mechanisms involved in wheat resistance against F. graminearum mycotoxins. Crude culture extract of F. graminearum was used to determine the physiological and molecular responses of wheat cultivars ‘Falat’ and ‘Sumai3‘, susceptible and resistant to FHB, respectively. Point inoculation of crude extract in the wheat spikelets resulted in significant increases in hydrogen peroxide (H2O2) and malondialdehyde (MDA) content in both cultivars, most likely due to oxidative stress. A greater induction level and activity of H2O2, MDA, peroxidase (POX), phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) was observed in the resistant versus the susceptible cultivar. In addition, quantitative real-time PCR indicated earlier and greater induction of PAL, pleiotropic drug resistance (PDR) and cytochrome P450 (CYP) gene expression in ‘Sumai3‘ compared with ‘Falat’. Responses associated with the resistant interaction in ‘Sumai3‘ were higher induction of superoxide dismutase (SOD) and POX and decreased activity of catalase, while decreased SOD activity was observed in ‘Falat’. Our data suggest that these responses could explain the higher degree of tolerance of ‘Sumai3‘ against F. graminearum.

Regulation of Inflammation by Sucrose Isomer, Turanose, in Raw 264.7 Cells

Increased sugar consumption has been proposed to be a risk factor for obesity-related metabolic disorders. The objective of this study was to investigate the anti-inflammatory effect of turanose in Raw 264.7 macrophages. Turanose (3-O-α-D-glucosyl-D-fructose), an isomer of sucrose, naturally exists in honey. For these studies, macrophages were treated with total glucose (Glu), 50% Glu/50% turanose (T50), 25% Glu/75% turanose (T75), and 100% turanose (T100), each with a total concentration of 25 mM in cell media. Expressions of inflammatory enzymes and cytokines were analyzed. Cell viability was not affected in the turanose treated groups compared to the Glu group. Lipopolysaccharide and glucose-induced nitric oxide production, protein expression of inducible nitric oxide synthase, COX-2, and superoxide dismutase 2, and mRNA expression levels of interleukin (IL)-1β and IL-18 were significantly suppressed by turanose treatment. These results demonstrate that turanose exerts anti-inflammatory effects in vitro, and possesses potential to serve therapeutic functional sweetener for testing in vivo and in clinical trials.