Intracellular Superoxide Dismutase Activity Research Articles

Supernatants of Bifidobacterium longum and Lactobacillus plantarum Strains Exhibited Antioxidative Effects on A7R5 Cells.

Vascular reactive oxygen species (ROS) play an essential role in cardiovascular diseases and the antioxidative effects of probiotics have been widely reported. To screen the probiotic strains that may prevent cardiovascular diseases, we tested the antioxidative effects of supernatants of different Bifidobacterium and Lactobacillus strains on A7R5 cells. Preincubation with supernatants of B. longum CCFM752, L. plantarum CCFM1149, or L. plantarum CCFM10 significantly suppressed the angiotensin II-induced increases in ROS levels and increased catalase (CAT) activity in A7R5, whereas CCFM752 inhibited NADPH oxidase activation and CCFM1149 enhanced the intracellular superoxide dismutase (SOD) activity simultaneously. Treatment with CCFM752, CCFM1149, or CCFM10 supernatants had no significant impact on transcriptional levels of Cat, Sod1, Sod2, Nox1, p22phox, or p47phox, but altered the overall transcriptomic profile and the expression of genes relevant to protein biosynthesis, and up-regulated the 60S ribosomal protein L7a (Rpl7a). A positive correlation between Rpl7a expression and intracellular CAT activity implied that Rpl7a may participate in CAT synthesis in A7R5. Supernatant of CCFM752 could also down-regulate the expression of NADPH oxidase activator 1 (Noxa1) and angiotensinogen in A7R5. Collectively, the probiotic strains CCFM752, CCFM1149, and CCFM10 exhibited antioxidative attributes on A7R5 cells and might help to reduce the risk of cardiovascular diseases.

Characterization of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg Roots and their effects on antioxidant activity and H2O2-induced oxidative damage in RAW 264.7 cells

This work presents an investigation on the composition and structure of polysaccharides from the roots of Tetrastigma hemsleyanum (THP) and its associated antioxidant activity. It further explores the protective effect of THP on RAW264.7 cells against cytotoxicity induced by H2O2. Ion chromatography (IC) revealed that THP contained glucose, arabinose, mannose, glucuronic acid, galactose and galacturonic acid, in different molar ratios. Furthermore, gel permeation chromatography-refractive index-multiangle laser light scattering (GPC-RI-MALS) was employed to deduce the relative molecular mass (Mw) of the polysaccharide, which was 177.1 ± 1.8 kDa. Fourier transform infrared spectroscopy (FT-IR) and Congo red binding assay highlighted that the THP had a steady α-triple helix conformation. Similarly, assays of antioxidant activity disclosed that THP had reasonable concentration-dependent hydroxyl radical and superoxide radical scavenging activities, peroxidation inhibition ability and ferrous ion chelating potency, in addition to a significant 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity. Moreover, THP could protect RAW264.7 cells against H2O2-induced cytotoxicity by decreasing intracellular ROS levels, reducing catalase (CAT) and superoxide dismutase (SOD) activities, increasing lactate dehydrogenase (LDH) activity and increment in malondialdehyde (MDA) level. Data retrieved from the in vitro models explicitly established the antioxidant capability of polysaccharides from T. hemsleyanum root extracts.

Mesenchymal Stem Cell-Conditioned Medium Protects Hippocampal Neurons From Radiation Damage by Suppressing Oxidative Stress and Apoptosis.

Objective:To investigate the effects of mesenchymal stem cell-conditioned medium (MSC-CM) on radiation-induced oxidative stress, survival and apoptosis in hippocampal neurons.Methods:The following groups were defined: Control, radiation treatment (RT), RT+MSC-CM, MSC-CM, RT + N-Acetylcysteine (RT+NAC), and RT + MSC-CM + PI3 K inhibitor (LY294002). A cell Counting Kit-8 (CCK-8) was used to measure cell proliferation. Apoptosis was examined by AnnexinV/PI flow cytometric analyses. Intracellular reactive oxygen species (ROS) were detected by DCFH-DA. Intracellular glutathione (GSH), malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity were detected by colorimetric assays. Protein levels of γ-H2AX, PI3K-AKT, P53, cleaved caspase-3, Bax, and BCl-2 were analyzed by Western blotting.Results:The proliferation of HT22 cells was significantly inhibited in the RT group, but was significantly preserved in the RT + MSC-CM group (P < 0.01). Apoptosis was significantly higher in the RT group than in the RT+ MSC-CM group (P < 0.01). MSC-CM decreased intracellular ROS and MDA content after irradiation (P < 0.01). GSH level and SOD activity were higher in the RT + MSC-CM group than in the RT group, as was MMP (P < 0.01). MSC-CM decreased expression of γ-H2AX, P53, Bax, and cleaved-caspase-3, but increased Bcl-2 expression (P < 0.01).Conclusion:MSC-CM attenuated radiation-induced hippocampal neuron cell line damage by alleviating oxidative stress and suppressing apoptosis.

Casein-maltodextrin Maillard conjugates encapsulation enhances the antioxidative potential of proanthocyanidins: An in vitro and in vivo evaluation

Practical application of proanthocyanidins (PAs) as antioxidants is limited because of their hard-to-maintained activities during the processes and storage and in severe gastrointestinal environments. To overcome this challenge, we have developed an easy and green method to encapsulate PAs based on casein-maltodextrin Maillard conjugates. The current work entails the systematic study on the antioxidative potentials of fabricated casein-maltodextrin-PAs nanoparticles (CMPNs). In vitro antioxidant activities of CMPNs remained well during storage in 28 days and treatments under 40–80 °C. In vivo Caenorhabditis elegans (C. elegans) model further showed that the CMPNs could prolong the lifespan of nematodes and protected nematodes from oxidative stress and heat shock. Analyses of intracellular superoxide dismutase and catalase activities also confirmed the existence of an antioxidant protective effect. Besides, in vitro release test showed that the encapsulation enhanced the bioaccessibility of PAs. These results have important implications for the development of novel antioxidants in nutraceutical industries.

Unconventionally Secreted Manganese Superoxide Dismutase VdSOD3 Is Required for the Virulence of Verticillium dahliae

Plant pathogens generally employ superoxide dismutase (SOD) to detoxify host defense reactive oxygen species (ROS), and to scavenge ROS derived from their own metabolism. However, the roles of SODs in an important vascular pathogen, Verticillium dahliae, are unclear. Our previous study has shown that a putative signal-peptide-lacking manganese superoxide dismutase (VdSOD3) is present in the exoproteome of V. dahliae cultured in tissues of host cotton, suggesting that VdSOD3 may be exported out of the fungal cells and contribute to the SOD activity extracellularly. Here, we confirm that the N-terminal of VdSOD3 is not a functional signal peptide by yeast signal trap assay. Despite lacking the signal peptide, the extracellular distribution of VdSOD3 was observed in planta by confocal microscopy during infection. Loss-of-function of VdSOD3 decreased extracellular and intracellular SOD activities of V. dahliae by 58.2% and 17.4%, respectively. Deletion mutant of VdSOD3 had normal growth and conidiation but showed significantly reduced virulence to susceptible hosts of cotton and Nicotiana benthamiana. Our data show that signal-peptide-lacking VdSOD3 is a dual function superoxide dismutase, localizing and functioning intracellularly and extracellularly. Whereas nonessential for viability, VdSOD3 plays a vital role in the virulence of V. dahliae.

The extract of Gnaphalium affine D. Don protects against H2O2-induced apoptosis by targeting PI3K/AKT/GSK-3β signaling pathway in cardiomyocytes

Ethnopharmacological relevanceGnaphalium affine D. Don is an important Traditional Chinese herbal Medicine (TCM) used to treat hyperuricemia, asthma, rheumatic arthritis, antitussive, expectorant and cardiovascular in folk medicine because of anti-inflammatory and anti-oxidant activity. The aim of this study was to investigate the potential beneficial effect of G. affine extract (GAE) on hydrogen peroxide (H2O2)-induced apoptosis and explore the possible underlying mechanism in cardiomyocyte. Materials and methodsThe ingredients of GAE were isolated and tentatively identified by HPLC-ESI-Q-Qribatrip-MS/MS. The cardioprotective and anti-oxidant effects of GAE were evaluated in the experimental model with H2O2 induced apoptosis in H9c2 cells. H9c2 cells were pretreated for 3 h with or without GAE or with GAE plus PX866 (PI3K inhibitor), then exposed to H2O2 for 6 h, H9c2 cells viability were detected by CCK8 kit, the content of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) and intracellular superoxide dismutase (SOD) activity were measured by the commercial biochemical kits, western blotting, immunohistochemical (IHC), immunofluorescence (IF) and reverse transcription-polymerase chain reaction (RT-PCR) assays were performed to evaluate the proteins and mRNA expression, propidium iodide (PI) staining was adopted to indicate H9c2 cells apoptosis. ResultsFirstly, seventeen polyphenols and flavonoids compounds with the characteristics of anti-inflammatory and anti-oxidant in GAE were tentatively identified by HPLC-ESI-Q-Qribatrip-MS/MS. In the experimental model, GAE not only significantly improved cells viability, but also showed anti-oxidant effects through improving SOD activity, up-regulating nuclear factor E2-related factor 2 (Nrf2), and decreasing intracellular concentration of ROS and MDA and the proteins expression of p47phox, p67phox and gp91phox. On the other hand, GAE revealed anti-apoptotic effect through up-regulating the expression of B-cell lymphoma-2 (Bcl-2), down-regulating Bcl2-associated X (BAX) and cleaved-caspase 3. Furthermore, GAE significantly facilitated phosphorylation of AKT and glycogen synthase kinase-3 beta (GSK-3β) but not AMPK, while the effects were blocked by PX866 (PI3K inhibitor). ConclusionsOur data suggested that GAE showed strong anti-oxidant effect to ameliorate oxidative stress and attenuate apoptosis induced by H2O2 in H9c2 cells by targeting PI3K/AKT/GSK-3β signaling pathway.

2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-Glucoside modulated human umbilical vein endothelial cells injury under oxidative stress.

Endothelial cell injury is a major contributor to cardiovascular diseases. The 2,3,5,4’-Tetrahydroxystilbene-2-O-β-D-Glucoside (TSG) contributes to alleviate human umbilical vein endothelial cells (HUVECs) injury through mechanisms still know a little. This study aims to clarify the TSG effects on gene expression (mRNA and microRNA) related to oxidative stress and endoplasmic reticulum stress induced by H2O2 in HUVECs. We found that TSG significantly reduced the death rate of cells and increased intracellular superoxide dismutase activity. At qRT-PCR, experimental data showed that TSG significantly counteracted the expressions of miR-9-5p, miR-16, miR-21, miR-29b, miR-145-5p, and miR-204-5p. Besides, TSG prevented the expression of ATF6 and CHOP increasing. In contrast, TSG promoted the expression of E2F1. In conclusion, our results point to the obvious protective effect of TSG on HUVECs injury induced by H2O2, and the mechanism may through miR16/ATF6/ E2F1 signaling pathway.

Selenoprotein T protects against cisplatin-induced acute kidney injury through suppression of oxidative stress and apoptosis.

Previously, selenoprotein T (SelT) expression was shown to be induced in nervous, endocrine, and metabolic tissues during ontogeneticand regenerative processes. However, whether SelT plays a critical role in renal diseases remains unclear. Here, we explored the role of SelT in cisplatin-induced acute kidney injury (AKI). Results revealed that SelT was highly expressed in renal tubules, but its expression was significantly reduced in cisplatin-induced AKI. Importantly, knocking down of SelT expression in kidney cells in vitro resulted in cisplatin-induced cell apoptosis, as indicated by the elevation of cleaved-PARP and Bax expression, Caspase-3 activity, and number of TUNEL-positive cells. Moreover, SelT silencing-induced reactive oxygen species (ROS) production, accompanied by a decrease in intracellular superoxide dismutase (SOD) and catalase (CAT) activity and increase in malondialdehyde (MDA) content. Notably, the protein and mRNA levels of Nox4 were increased in response to SelT downregulation. Furthermore, suppression of Nox4 expression by GKT137831 partially alleviated SelT knockdown-induced ROS generation and cell apoptosis in cisplatin-treated kidney cells. Taken together, our findings provide the first evidence that SelT protects against cisplatin-induced AKI by suppression of oxidative stress and apoptosis.

P1143REDOX PROFILING IN MESOTHELIAL CELLS IN EXPERIMENTAL PERITONEAL DIALYSIS

Abstract Background and Aims PD-fluids lead to generation of reactive oxygen species (ROS) in the peritoneal cavity. The caused oxidative stress, defined as a cellular oxidant-antioxidant imbalance impairs not only peritoneal cell viability but also contributes to progression of local and systemic PD-related pathomechanisms. We aim to analyze the impact and specific targets of ROS during PD and the anti-oxidative mechanism of supplementation of PD-fluid with alanyl-glutamine (AlaGln) on a global proteome-wide level. Method To establish a redox-proteomics workflow for studying oxidative stress in peritoneal mesothelial cells we used a gold-standard model of redox-stress (H2O2) and PD-fluid induced stress. Levels of oxidative stress were first validated by increased intracellular ROS and superoxide dismutase activity with PD-fluid and H2O2 treatment and a reduction of these parameters by the addition of AlaGln. To detect alterations of the redox proteome, cysteine residues were either directly or indirectly labeled with fluorescent dyes (redox-2D-DiGE) or isobaric tags (iodo-TMT). Results: The gel-based approach allowed global visualization of the reduced and oxidized cysteines and revealed redox profiles of 540 protein spots. Compared to control, we found an increase in oxidized and decrease in reduced cysteines in all PD treatments. The development of a highly sensitive LC/MS-based redox proteomics workflow allowed identification of ∼950 proteins affected by redox-stress in mesothelial cells and confirmed the quantitative levels seen on cysteine oxidation. The addition of AlaGln reduced the overall redox status (intracellular ROS and superoxide dismutase activity) but further showed different proteins to be affected by redox modifications. Conclusion: Redox proteomics of peritoneal cells could represent a novel approach for the identification of mediators of PD-induced pathomechanisms, but also to evaluate effects of novel anti-oxidant therapeutical or pharmacological interventions.

Improvement of the production of an Arctic bacterial exopolysaccharide with protective effect on human skin cells against UV-induced oxidative stress.

Although microbial exopolysaccharides (EPSs) are applied in different fields, no EPS has been used to protect human skin cells against UV-induced oxidative stress. The EPS produced by the Arctic bacterium Polaribacter sp. SM1127 has high moisture-retention ability and antioxidant activity, suggesting its good industrial potentials. In this study, we improved the EPS production of SM1127 and evaluated its protective effect on human dermal fibroblasts (HDFs) against UV-induced oxidative stress. With glucose as carbon source, the EPS yield was increased from 2.11 to 6.12g/L by optimizing the fermentation conditions using response surface methodology. To lower the fermentation cost and decrease corrosive speed in stainless steel tanks, whole sugar, whose price is only 8% of that of glucose, was used to replace glucose and NaCl concentration was reduced to 4g/L in the medium. With the optimized conditions, fed-batch fermentation in a 5-L bioreactor was conducted, and the EPS production reached 19.25g/L, which represents the highest one reported for a polar microorganism. Moreover, SM1127 EPS could maintain the cell viability and integrity of HDFs under UV-B radiation, probably via decreasing intracellular reactive oxygen species level and increasing intracellular glutathione content and superoxide dismutase activity. Therefore, SM1127 EPS has significant protective effect on HDFs against UV-induced oxidative stress, suggesting its potential to be used in preventing photoaging and photocarcinogenesis. Altogether, this study lays a good foundation for the industrialization of SM1127 EPS, which has promising potential to be used in cosmetics and medical fields.

Cytotoxicity of perfluorodecanoic acid on mouse primary nephrocytes through oxidative stress: Combined analysis at cellular and molecular levels

Long-chain perfluoroalkyl acids (PFAAs) such as perfluorodecanoic acid (PFDA) are toxic, persistent organic pollutants. This study investigated the harmful effect of PFDA on mouse primary nephrocytes and its mechanism at cellular and molecular levels. Cellular results showed that PFDA exhibited nephrotoxicity with decreased cell viability and increased apoptosis. The increase of intracellular reactive oxygen species (ROS) content and the decrease of intracellular superoxide dismutase (SOD) activity were significant (p < 0.01) when PFDA concentration exceeded 10 μM. Additionally, the molecular results indicated that PFDA bind with Val-A98 in the surface of Cu/Zn-SOD by a 3.11 Å hydrogen bond driven by Van der Waals’ force and hydrogen bonding force, which triggered the structural changes and decreased activity of Cu/Zn-SOD. Altogether, the intracellular oxidative stress is the main driver of nephrocyte apoptosis; and the interaction of PFDA and Cu/Zn-SOD exacerbated the oxidative stress in nephrocytes, which is also a nonnegligible reason of cytotoxicity induced by PDFA. This study represented a meaningful method to explore the toxic effect and mechanism of xenobiotics at cellular and molecular levels. The findings have implications for revealing the clearance of long-chain PFAAs in vivo.

Stilbene glucoside inhibits ultraviolet radiation B-induced photoaging in human skin fibroblasts

To study the effects of tetrahydroxy stilbene-2-O-β-D-glucoside (TSG) on stress-induced premature senescence of human skin fibroblasts (HSF) exposed to ultraviolet radiation B (UVB) and its possible mechanism. HSFs were repeatedly exposed to UVB at a subcytotoxic level. TSG treatment (0.02, 0.10 and 0.50 mmol/L) was given immediately after each irradiation. The HSFs were divided into six groups:blank control group, model group, UVB+0.02 mmol/L TSG group, UVB+0.10 mmol/L TSG group, UVB+0.50 mmol/L TSG and TSG group (0.50 mmol/L). Cell counting kit-8 (CCK-8) was used to evaluate the proliferative activity of cells; senescence-associated-β-galactosidase (SA-β-gal) staining was performed to estimate the degree of premature senescence in cells; TBA method and WST-1 method were used to detect intracellular malondialdehyde (MDA) and superoxide dismutase (SOD) activities; and ELISA was applied to quantify the secretion level of matrix metalloproteinase1 (MMP-1) in cultured supernatant. Compared with the blank control group, the proliferative activity and SOD level in the model group decreased (P<0.05), while the percentage of SA-β-gal-positive cells, MDA and MMP-1 levels increased (P<0.05 or P<0.01). Compared with the model group, the proliferative activity and SOD level increased in UVB+TSG groups (all P<0.05), and the percentage of SA-β-gal-positive cells, MDA and MMP-1 levels decreased (P<0.05 or P<0.01). TSG can inhibit UVB-induced premature senescence of HSF, which may be related to the inhibition of oxidative stress and high expression of MMP-1.

Relationship among intracellular superoxide dismutase activity, glutathione peroxidase activity, motility and morphology in human semen

Relationship among intracellular superoxide dismutase activity, glutathione peroxidase activity, motility and morphology in human semen

Apoptotic effects of rhein through the mitochondrial pathways, two death receptor pathways, and reducing autophagy in human liver L02 cells.

Rhein (4,5-dihydroxyanthraquinone-2-carboxylic acid) is a major component of many medicinal herbs such as Rheum palmatum L. and Polygonum multiflorum. Despite being widely used, intoxication cases associated with rhein-containing herbs are often reported. Currently, there are no available reports addressing the effects of rhein on apoptosis in human liver L02 cells. Thus, the aim of this study is to determine the cytotoxic effects and the underlying mechanism of rhein on human normal liver L02 cells. In the present study, the methyl thiazolyl tetrazolium assay demonstrated that rhein decreased the viability of L02 cells in dose-dependent and time-dependent ways. Rhein was found to trigger apoptosis in L02 cells as shown by Annexin V-fluoresceine isothiocyanate (FITC) apoptosis detection kit and cell mitochondrial membrane potential (MMP) assay, with nuclear morphological changes demonstrated by Hoechst 33258 staining. Detection of intracellular superoxide dismutase activity, lipid oxidation (malondialdehyde) content, and reactive oxygen species (ROS) levels showed that apoptosis was associated with oxidative stress. Moreover, it was observed that the mechanism implicated in rhein-induced apoptosis was presumably via the death receptor pathway and the mitochondrial pathway, as illustrated by upregulation of TNF-α, TNFR1, TRADD, and cleaved caspase-3, and downregulation of procaspase-8, and it is suggested that rhein may increase hepatocyte apoptosis by activating the increase of TNF-α level. Meanwhile, rhein upregulates the expression of Bax and downregulates the expression of procaspase-9 and -3, and it is suggested that the mitochondrial pathway is activated and rhein-induced apoptosis may be involved. In addition, we also want to explore whether rhein-induced apoptosis is related to the autophagic changes induced by rhein. The results showed that rhein treatment increased P62 and decreased LC3-II and beclin-1, which means that autophagy was weakened. The results of our studies indicated that rhein induced caspase-dependent apoptosis via both the Fas death pathway and the mitochondrial pathway by generating ROS, and meanwhile the autophagy tended to weaken.

Effect of euphorbia factor L1 on oxidative stress, apoptosis, and autophagy in human gastric epithelial cells

BackgroundEuphorbia factor L1 (EFL1), a lathyrane-type diterpenoid from the medicinal herb Euphorbia lathyris L. (Euphorbiaceae), has been reported for many decades to induce gastric irritation, but the underlying mechanisms remain unclear. PurposeThe objective of this study was to investigate EFL1-induced cytotoxicity and the potential mechanisms of action on the human normal gastric epithelial cell GES-1. MethodsGES-1 cells were treated with EFL1 (12.5–200 μM) for different time intervals, and cell survival, LDH release, intracellular reactive oxygen species (ROS), malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity were detected. Mitochondrial membrane potential (MMP) assay, DAPI staining, DNA fragment assay, and annexin V-FITC/PI staining were performed. The interaction between EFL1 and Bcl-2, cytochrome c, caspase-9, caspase-3, PI3K, AKT, and mTOR proteins was simulated by molecular docking. The mRNA and protein expression of apoptosis and autophagy factors were detected by RT-qPCR and Western blotting. ResultsEFL1 decreased survival, increased LDH leakage, and induced abnormal production of ROS, MDA and SOD in GES-1 cells. Mitochondria-mediated apoptosis was characterized by decreased MMP, condensed nuclei, fragmented DNA, and increased apoptosis rate. EFL1 interacted with proteins via hydrogen bonding. The mRNA, total or phosphorylated protein expression of Bcl-2, mitochondrial cytochrome c, PI3K, AKT, mTOR and p62 were downregulated; in contrast, those of cytoplasmic cytochrome c, cleaved caspase-9, cleaved caspase-3, LC3-ll and Beclin-1 were upregulated. ConclusionThese findings indicated that EFL1 decreased the survival of GES-1 cells through EFL1-induced oxidative stress, activation of the mitochondria-mediated apoptosis as well as autophagy via inhibition of the PI3K/AKT/mTOR pathway.

170 The effects of linoleic and linolenic acid supplementation on the in vitro maturation of pig oocytes in a heat-stressed environment

Elevated environmental temperatures induce heat stress, which can cause a depression in fertility and early embryonic development. Fatty acids initiate an endergonic reaction that is able to absorb cellular heat, causing a decrease in intracellular temperature. Supplementing linoleic and linolenic acids to the maturation medium of pig oocytes at elevated temperatures reduces the effects of heat stress-induced damage during fertilization and embryonic development. However, the mechanism of action of fatty acids during oocyte maturation is unknown. Therefore, the objective of this study was to minimize heat stress-induced damage and characterise the intracellular oocyte mechanisms. Oocyte maturation media was supplemented with linoleic and linolenic acid during oocyte maturation at either 38.5 or 41.5°C. Oocytes (n=3094, r=5) were supplemented with 50μM linoleic acid, 50μM linolenic acid, 25μM of both, or 50μM of both during 40 to 44h of maturation and then evaluated for the formation of reactive oxygen species (n=239), intracellular glutathione concentrations (n=1005), glutathione peroxidase (n=1005), catalase (n=987), and superoxide dismutase (n=863) activities. Data were analysed using ANOVA with the main effects including treatment, well, and replicate. There were no significant differences between the treatment groups matured at 38.5°C when comparing reactive oxygen species generation. Supplementation of linoleic or linolenic acid significantly decreased (P&amp;lt;0.05) reactive oxygen species generation in oocytes matured at 41.5°C compared with no supplementation at the same temperature. Supplementation of linoleic or linolenic acid or both significantly increased (P&amp;lt;0.05) intracellular glutathione concentrations compared with no supplementation at 38.5°C (23.37±1.23 pmol/oocyte) and 41.5°C (10.42±1.01 pmol/oocyte). There were no significant differences between the treatment groups matured at 38.5°C or 41.5°C when comparing glutathione peroxidase activity. Supplementation of linoleic or linolenic acid or both significantly increased (P&amp;lt;0.05) catalase and superoxide dismutase activities compared with no supplementation at 38.5°C and at 41.5°C. Superoxide dismutase activity was significantly higher (P&amp;lt;0.05) in oocytes matured at 41.5°C compared with those matured at 38.5°C. These results indicate that supplementing linoleic and linolenic acid to the maturation medium of pig oocytes at an elevated temperature reduces the effects of heat stress-induced damage by increasing intracellular glutathione concentrations and catalase and superoxide dismutase activities.

Antioxidant activities of four superoxide dismutases in Metarhizium robertsii and their contributions to pest control potential.

The superoxide dismutase (SOD) family of Metarhizium robertsii, a fungal insect pathogen, comprises six members functionally unknown yet, including Cu/ZnSODs (Sod1/5/6), MnSODs (Sod2/3), and FeSOD (Sod4). Here, we show a mitochondrial localization of Sod3 and Sod4 and a requirement of either sod4 or sod6 for the fungal life as suggested by an inability to be deleted. We found remarked roles of Sod1, Sod2, and Sod3 in sustaining antioxidant activity and the fungal potential against insect pests but no role of Sod5 in all examined phenotypes. Intracellular SOD activity decreased by 49% in Δsod1 and 22% in either Δsod2 or Δsod3. The decreased SOD activities concurred with altered enzymographs, in which one of two SOD-active bands in wild-type and rescued strains disappeared in Δsod1 rather than in Δsod2 and another band disappeared in Δsod3. Consequently, maximal cell sensitivity to superoxide anions generated by oxidant menadione occurred in Δsod1, followed sequentially by Δsod3 and Δsod2. The latter two mutants were more sensitive than Δsod1 to oxidant H2O2. Transcriptional analysis revealed partial compensation of one or two partner genes upregulated for the absence of sod1, sod2, or sod3 and full compensation of three partners largely upregulated for the absence of sod5, as well as differential expression of most catalase genes in each Δsod mutant. The three mutants also suffered defects in conidial thermotolerance, UVB resistance, and virulence. These findings unveil that, to adapt to different host spectra and habitats, some major SODs in M. roberstii are functionally differentiated from those known previously in Beauveria bassiana, a classic insect mycopathogen lacking Sod6.

Wild Andean blackberry (Rubus glaucus Benth) and Andean blueberry (Vaccinium floribundum Kunth) from the Highlands of Ecuador: Nutritional composition and protective effect on human dermal fibroblasts against cytotoxic oxidative damage

BACKGROUND: Andean blackberries (Rubus glaucus Benth) and Andean blueberries (Vaccinium floribundum Kunth) are wild berries consumed and commercialised by the indigenous people of the Andean regions of Ecuador. OBJECTIVE: This study aims to determine the chemical composition and the ability of A. blackberries and A. blueberries to protect human dermal fibroblast (HDFa) against cytotoxic oxidative damage. METHODS: Total phenolic, flavonoid, anthocyanins and tannins content were determined spectrophotometrically, while vitamin C and carotenes were determined by HPLC. Total antioxidant capacity was determined by the Ferric Reducing Antioxidant Power (FRAP) assay, the hydrogen peroxide scavenging activity and the DPPH and superoxide radical scavenging capacity. HDFa was pre-treated with A. blackberries or A. blueberries crude extract, subjected to a model of oxidative stress using the stressor 2,2’-azobis(2-amidinopropane) dihydrochloride (AAPH) and the markers of cell cytotoxic damage (intracellular ROS levels, catalase, superoxide dismutase and glutathione activities, lipid peroxidation, protein oxidation and ATP and nitrite levels) were determined. RESULTS: A. blueberries showed significantly high values of total phenolic, flavonoid, anthocyanin, lutein tannin content, whilst A. blackberries showed the highest values of vitamin C and β-carotene. After HDFa was pre-incubated with crude extracts of A. blackberries and A. blueberries, the markers of oxidative damage were significantly improved compared with the stressed cells group. In all cases, crude extract of A. blueberries showed a higher protective effect compared to A. blackberries. CONCLUSION: A. blackberry and A. blueberry attenuated the oxidative damage in HDFa showing that both fruits may represent a relevant source of bioactive compounds with promising benefits for human health.

Toxicological assessment of multi-walled carbon nanotubes combined with nonylphenol in male mice

Carbon nanotubes have attracted increasing attention attributable to their widespread application. To evaluate the joint toxicity of multi-walled carbon nanotubes (MWCNTs) and nonylphenol (NP), we investigated the toxicological effects of NP, pristine MWCNTs, and MWCNTs combined with NP in male mice. After exposing male mice by gavage for 5 days, intracellular superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity, as well as malondialdehyde (MDA) and glutathione (GSH) levels in tissues were determined to evaluate in vivo oxidative stress. In addition, genotoxicity was assessed by examining DNA damage in mouse liver and sperm via the comet assay, and transmission electron microscopy (TEM) was used for direct visual observations of mitochondrial damage in the liver. Results from the oxidative damage and DNA damage experiments indicate that after adsorbing NP, MWCNTs at a high dose induce oxidative lesions in the liver and cause DNA damage in mouse sperm; these data offer new insights regarding the toxicological assessment of MWCNTs.

Ferulic acid protects against heat stress-induced intestinal epithelial barrier dysfunction in IEC-6 cells via the PI3K/Akt-mediated Nrf2/HO-1 signaling pathway

Purpose: Intestinal epithelial barrier dysfunction is crucial in the pathogenesis of intestinal and systemic diseases. Ferulic acid (FA) possesses promising antioxidant activities. In a previous study, we demonstrated potentially protective effects of FA against heat stress-induced intestinal epithelial barrier dysfunction in IEC-6 cells. However, the underlying mechanisms are unclear. The present study aimed to elucidate whether FA protects IEC-6 cells from heat stress-induced intestinal epithelial barrier dysfunction via antioxidative mechanisms.Materials and methods: IEC-6 cells were pretreated with FA prior to hyperthermia exposure at 42 °C for 6 h, and the levels of intracellular reactive oxygen species (ROS), malondialdehyde (MDA), nitrogen oxide (NO), and superoxide dismutase (SOD) activity were analyzed. The intestinal epithelial barrier function was determined by transepithelial electrical resistance (TER) values and 4-kDa fluorescein isothiocyanate-dextran (FD4) flux in IEC-6 cell monolayers. Expression of related proteins was detected by Western blotting.Results: FA suppressed heat stress-induced intestinal oxidative stress damage by reducing ROS, MDA and NO production, while enhancing SOD activity. Furthermore, FA treatment strengthened intestinal barrier function via increasing the phosphorylation levels of Akt, nuclear factor-erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1) protein expression, which was reversed by zinc protoporphyrin (an HO-1 inhibitor). Additionally, LY294002, a specific PI3K/Akt inhibitor, significantly suppressed FA-induced Nrf2 nuclear translocation and HO-1 protein expression and inhibited FA-induced occludin and ZO-1 protein expression.Conclusions: FA protected against heat stress-induced intestinal epithelial barrier dysfunction via activating the PI3K/Akt-mediated Nrf2/HO-1 signaling pathway in IEC-6 cells.