Mn Single-Atom Nanozymes with Superior Loading Capability and Superb Superoxide Dismutase-like Activity for Bioassay.

Single-atom nanozymes (SANs) with highly exposed active sites and remarkable catalytic activity have shown noteworthy practicability in heterogeneous catalysis-based bioassay. Nevertheless, most of them were reported with peroxidase-like activity and ordinary loading capability. It is still a challenge to prepare high-loading SANs with desirable superoxide dismutase (SOD)-like activity. In this work, Mn SAN was successfully confined in the frameworks of Prussian blue analogues formed on Ti3C2 MXene sheets with the assistance of massive surfactants, which show a superior loading efficiency of 13.5 wt % (typically <2.0 wt %). The prepared Mn SAN exhibits desirable superoxide radical anion elimination capability because of its SOD-like activity. Moreover, due to the wide-spectrum absorption behavior of the carriers, Mn SAN shows a synergistically quenching efficiency up to 98.89% on the emission of the reactive oxygen species-mediated chemiluminescent (CL) system. Inspired by these features, a CL quenching method was developed on a lateral flow test strip platform by utilizing Mn SAN as a signal quencher and acetamiprid as a model analyte. The method for detecting acetamiprid shows a detection range of 1.0-10,000 pg mL-1 and a limit of detection of 0.3 pg mL-1. Its accuracy has been validated by detecting acetamiprid in medicinal herbs with acceptable recoveries. This work opens an avenue for preparing SANs with a surfactant-assisted protocol and pioneers the study of SANs with SOD-like activity in bioassay.

Scavenging of Superoxide in Aprotic Solvents of Four Isoflavones That Mimic Superoxide Dismutase.

Isoflavones are plant-derived natural products commonly found in legumes that show a large spectrum of biomedical activities. A common antidiabetic remedy in traditional Chinese medicine, Astragalus trimestris L. contains the isoflavone formononetin (FMNT). Literature reports show that FMNT can increase insulin sensitivity and potentially target the peroxisome proliferator-activated receptor gamma, PPARγ, as a partial agonist. PPARγ is highly relevant for diabetes control and plays a major role in Type 2 diabetes mellitus development. In this study, we evaluate the biological role of FMNT, and three related isoflavones, genistein, daidzein and biochanin A, using several computational and experimental procedures. Our results reveal the FMNT X-ray crystal structure has strong intermolecular hydrogen bonding and stacking interactions which are useful for antioxidant action. Cyclovoltammetry rotating ring disk electrode (RRDE) measurements show that all four isoflavones behave in a similar manner when scavenging the superoxide radical. DFT calculations conclude that antioxidant activity is based on the familiar superoxide σ-scavenging mode involving hydrogen capture of ring-A H7(hydroxyl) as well as the π-π (polyphenol-superoxide) scavenging activity. These results suggest the possibility of their mimicking superoxide dismutase (SOD) action and help explain the ability of natural polyphenols to assist in lowering superoxide concentrations. The SOD metalloenzymes all dismutate O2•- to H2O2 plus O2 through metal ion redox chemistry whereas these polyphenolic compounds do so through suitable hydrogen bonding and stacking intermolecular interactions. Additionally, docking calculations suggest FMNT can be a partial agonist of the PPARγ domain. Overall, our work confirms the efficacy in combining multidisciplinary approaches to provide insight into the mechanism of action of small molecule polyphenol antioxidants. Our findings promote the further exploration of other natural products, including those known to be effective in traditional Chinese medicine for potential drug design in diabetes research.

Application of Spectroscopic Methods for the Identification of Superoxide Dismutases in Cyanobacteria.

Superoxide dismutases (SODs) belong to the group of metalloenzymes that remove superoxide anion radicals and they have been identified in three domains of life: Bacteria, Archaea and Eucarya. SODs in Synechocystis sp. PCC 6803, Gloeobacter violaceus CCALA 979, and Geitlerinema sp. ZHR1A were investigated. We hypothesized that iron (FeSOD) and/or manganese (MnSOD) dominate as active forms in these cyanobacteria. Activity staining and three different spectroscopic methods of SOD activity bands excised from the gels were used to identify a suitable metal in the separated samples. FeSODs or enzymes belonging to the Fe-MnSOD superfamily were detected. The spectroscopic analyses showed that only Fe is present in the SOD activity bands. We found FeSOD in Synechocystis sp. PCC 6803 while two forms in G. violaceus and Geitlerinema sp. ZHR1A: FeSOD1 and FeSOD2 were present. However, no active Cu/ZnSODs were identified in G. violaceus and Geitlerinema sp. ZHR1A. We have shown that selected spectroscopic techniques can be complementary to the commonly used method of staining for SOD activity in a gel. Furthermore, the occurrence of active SODs in the cyanobacteria studied is also discussed in the context of SOD evolution in oxyphotrophs.

Cloning of Mn-SOD gene and its mRNA expression difference and antioxidant enzyme activities under hypoxia stress of cobia Rachycentron canadum.

BACKGROUND: Environmental hypoxia affects the survival and development of organisms. It is also an important environmental factor that leads to oxidative damage. Hypoxia is a condition in which tissues are deprived of oxygen; reoxygenation is the phenomenon in which hypoxic tissues are exposed to oxygen. Hypoxia-reoxygenation is vital in pathogenesis, where the production of reactive oxygen species and antioxidant disparity significantly contribute to disease progression, and it is one of the most common physiological stressors in the aquaculture industry. METHODS AND RESULTS: In this study, the full length of complementary DNA (cDNA) of the manganese superoxide dismutase (Mn-SOD) gene of healthy cobia Rachycentron canadum was analysed using rapid amplification of cDNA ends. The real-time quantitative Polymerase Chain Reaction was used to measure the expression levels of Mn-SOD mRNAs in various tissues (heart, muscle, brain, liver, kidney, gill, intestine, and spleen). The 2-ΔΔCT method was used to performed the expression analysis. The experimental data were analysed using SPSS ver. 19.0 ( https://spss.software.informer.com/19.0/ ). P < 0.05 and P < 0.01 were set as significant differences. The values were articulated as mean ± standard deviation. The Mn-SOD gene cDNA sequence was 1209 bp long, including a 684 bp open reading frame, 42 bp 5'UTR and 483 bp 3'UTR, encoding 227 amino acids. Under hypoxia-reoxygen stress, the expression of Mn-SOD in brain tissue was significantly lower than in the control group after 8 h of reoxygenation and higher than the control group after 24 h. Hypoxia and subsequent reoxygenation triggered a disturbance in antioxidant homeostasis, displayed in the modification of GPx expression/activity in the liver: GPx was improved. CONCLUSIONS: These results provide valuable information on the role of Mn-SOD regulation in oxidative stress caused by hypoxia.

Antioxidant Activity in Rheum emodi Wall (Himalayan Rhubarb).

Using natural products as antioxidant agents has been beneficial to replace synthetic products. Efforts have been made to profile the antioxidant capacities of natural resources, such as medicinal plants. The polyphenol content of Himalayan rhubarb, Rheum emodi wall, was measured and the antioxidant activity was determined using DPPH and ABTS+ assay, and the oxidative stress was assessed using SOD enzymatic assay. Five different solvent fractions, n-hexane, n-butanol, ethyl acetate, dichloromethane, and water, were used for screening the antioxidant capacity in effort to determine the optimum extraction solvent. The total phenolic contents for R. emodi fractions ranged from 27.76 to 209.21 mg of gallic acid equivalents (GAE)/g of dry weight. DPPH and ABTS+ assay results are presented into IC50 values, ranged from 21.52 to 2448.79 µg/mL and 90.25 to 1718.05 µg/mL, respectively. The ethyl acetate fraction had the highest antioxidant activity among other fractions. Also, n-butanol and water fractions showed significantly lower IC50 values than the positive control in DPPH radical scavenging activity. The IC50 values of SOD assay of fractions ranged from 2.31 to 64.78 µg/mL. A similar result was observed with ethyl acetate fraction showing the highest SOD radical scavenging activity. The study suggests that the ethyl acetate fraction of R. emodi possess the strongest antioxidant activity, thus the most efficient in extracting antioxidant contents. Moreover, a highly significant correlation was shown between total polyphenol content and antioxidant activity screening assays. The compounds related to the antioxidant activity of R. emodi were identified to myricitrin, myricetin 3-galloyl rhamnoside, and myricetin, which have not been reported in studies about R. emodi before.

Molecular cloning, expression, and characterization of BmSOD3 in silkworm (Bombyx mori).

Superoxide dismutases (SODs) play an essential role in eliminating excess reactive oxygen species and maintaining the redox balance of the immune system. To study the function of BmSOD3 in silkworm, 543-bp full-length complementary DNA-encoding BmSOD3 was cloned from silkworm. The BmSOD3 amino acids were compared to their homologs, and several highly conserved regions were analyzed. We also carried out phylogenetic analyses of the SOD gene. Our results showed that the BmSOD3 gene belonged with the ecCu/Zn SOD gene. The BmSOD3 gene was transformed into the pET28a vector for functional expression in Escherichia coli. The sodium salt-polyacrylamide gel electrophoresis results showed that the molecular weight of recombinant BmSOD3 was about 22 kDa. The recombinant protein BmSOD3 was purified to detect its properties. After purification analyses, the enzyme activity showed Cu/Zn SOD activity, and the specific activity of the purified enzyme was 0.51 U/mg. The BmSOD3 transcripts showed tissue-specific expression in the midgut and malpighian tubule. The immune microarray data for BmSOD3 showed an expression signal that had a strong response to the induction of four pathogens (Bacillus bombyseptieus, Beauveria bassiana, E. coli, and nuclear polyhedrosis virus), particularly after infection for 24 h, which indicates that the BmSOD3 gene plays a key role in response to bacterial, fungal, and viral invasion. The fusion protein also showed antibacterial activity against E. coli in vitro. Thus, the fusion protein BmSOD3 exhibits antibacterial activity and may be used in production to combat diseases caused by bacteria in silkworm.

Strategies to expand the therapeutic potential of superoxide dismutase by exploiting delivery approaches.

The overproduction of free radicals can cause oxidative-stress damage to a range of biomolecules, and thus potentially contribute to several pathologies, from neurodegenerative disorders to cardiovascular diseases and metabolic disorders. Endogenous antioxidant enzymes, such as superoxide dismutase (SOD), play an important role in diminishing oxidative stress. SOD supplementation could therefore be an effective preventive strategy to reduce the risk of free-radical overproduction. However, the efficacy of SOD administration is hampered by its rapid clearance. Several different approaches to improve the bioavailability of SOD have been explored in recent decades. This review intends to describe the rationale that underlie the various approaches and chemical strategies that have led to the most recent advances in SOD delivery. This critical description includes SOD conjugates, SOD loaded into particulate carriers (micelles, liposomes, nanoparticles, microparticles) and the most promising and suitable formulations for oral delivery, with a particular emphasis on reports of preclinical/clinical results. Likely future directions are also considered and reported.

Serum and milk concentrations of oxidant and anti-oxidant markers in dairy cows affected with bloody milk.

This study was conducted to determine the serum and milk levels of thiobarbturic acid-reac- tive substances (TBARS), nitric oxide (NO), superoxide dismutase (SOD), glutathione peroxi- dase (GSH-Px), vitamin E and selenium, IL-4 and IL-6 in lactating dairy cows affected with bloody milk using commercially available ELISA kits. Milk and whole blood samples were collected from 60 cows affected with bloody milk and 20 apparently healthy cows for control. In the serum, levels of GSH-Px and SOD were significantly (p˂0.05) higher in healthy cows compared to cows affected with bloody milk while the levels of TBARS and NO were significantly (p˂0.05) higher in affected cows. In the milk, levels of SOD, TBARS and NO were significantly (p˂0.05) higher in affected cows. In the serum, levels of vitamin E were significantly (p˂0.05) lower in affected cows compared to healthy cows, while no significant changes were observed in the levels of this vitamin in the milk between healthy and affected cows. In the serum, levels of selenium were significantly (p˂0.05) lower in affected cows while in milk, selenium levels were significantly (p˂0.05) higher in affected cows compared to healthy ones. Levels of IL-4 were significantly (p˂0.05) lower in the serum and milk of affected cows compared to healthy cows while levels of IL-6 were significantly (p˂0.05) higher in both serum and milk of affected cows. Results of this study suggest a possible role of oxidative stress in the pathogenesis of bloody milk in dairy cows.

Function of hesperidin alleviating inflammation and oxidative stress responses in COPD mice might be related to SIRT1/PGC-1α/NF-κB signaling axis.

Purpose: Hesperidin has anti-inflammatory and anti-oxidant stress effects, but its functions in chronic obstructive pulmonary disease (COPD) remains unknown. This study analyzed the role of hesperidin in COPD mice, aiming to provide a basis for the hesperidin application.Materials and methods: Mice were injected with cigarette smoke extract (CSE) to construct COPD models and then treated with budesonide or hesperidin. Hematoxylin-eosin (HE) and TUNEL assays were used to observe the pathological changes and cell death of lung tissue. The levels of interleukin (IL)-6, IL-8, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) in bronchoalveolar lavage fluid (BLAF), as well as myeloperoxidase (MPO) content in lung tissues were confirmed. The expression levels of SIRT1, PGC-1α, and p65 proteins were measured by western blotting (WB) analysis.Results: CSE induced inflammatory cell infiltration and cell death in the lung tissues of mice, whereas budesonide and hesperidin effectively alleviated these pathological changes. The levels of IL-6, IL-8, and MDA in BLAF and pulmonary MPO content in the COPD mice were effectively increased, while the levels of SOD and CAT in BLAF were decreased, which could be reversed by budesonide and hesperidin. Moreover, the addition of budesonide or hesperidin reliably accelerated the expression levels of PGC-1α and SIRT1 but suppressed the phosphorylation of p65 in COPD mice. In general, high-dose hesperidin had a stronger regulatory effect on COPD mice.Conclusions: Hesperidin alleviated inflammation and oxidative stress responses in CES-induced COPD mice, associated with SIRT1/PGC-1α/NF-κB signaling axis, which might become a new direction for COPD treatment.

Anti-oxidative effects of superoxide dismutase 3 on inflammatory diseases.

Free radicals and other oxidants are critical determinants of the cellular signaling pathways involved in the pathogenesis of several human diseases including inflammatory diseases. Numerous studies have demonstrated the protective effects of antioxidant enzymes during inflammation by elimination of free radicals. The superoxide dismutase (SOD), an antioxidant enzyme, plays an essential pathogenic role in the inflammatory diseases by not only catalyzing the conversion of the superoxide to hydrogen peroxide and oxygen but also affecting immune responses. There are three distinct isoforms of SOD, which distribute in different cellular compartments such as cytosolic SOD1, mitochondrial SOD2, and extracellular SOD3. Many studies have investigated the anti-oxidative effects of SOD3 in the inflammatory diseases. Herein, in this review, we focus on the current understanding of SOD3 as a therapeutic protein in inflammatory diseases such as skin, autoimmune, lung, and cardiovascular inflammatory diseases. Moreover, the mechanism(s) by which SOD3 modulates immune responses and signal initiation in the pathogenesis of the diseases will be further discussed.

Antioxidant supplementation to medium for in vitro embryo production in Felis catus.

The development of in vitro embryo production (IVEP) techniques in Felis catus is a fitting model with potential application to the conservation of endangered felid species. To improve the quality of IVEP techniques an appropriate balance of pro- and antioxidants should be provided. Under in vitro conditions, high levels of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) mRNA provide a defence mechanism against oxidative stress for embryos. In order to improve the development of cat oocytes, the effects of SOD and CAT supplemented to in vitro maturation (IVM) medium and of GPx supplemented to in vitro fertilization (IVF) medium on development and embryo production in vitro were evaluated. Data showed an increase of 70 and 77 % of cleaved embryo and blastocyst formation, respectively, in the experiment with SOD and CAT addition to IVM medium; in the experiment with GPx addition to IVF medium the number of cleaved embryos doubled and the number of embryos increased by 96 %. Therefore, our results were positive and encourage us to continue studies on cat oocytes evaluating the effects of various dosages and combination of antioxidants.

A superoxide scavenging coating for improving tissue response to neural implants.

The advancement of neural prostheses requires implantable neural electrodes capable of electrically stimulating or recording signals from neurons chronically. Unfortunately, the implantation injury and presence of foreign bodies lead to chronic inflammation, resulting in neuronal death in the vicinity of electrodes. A key mediator of inflammation and neuronal loss are reactive oxygen and nitrogen species (RONS). To mitigate the effect of RONS, a superoxide dismutase mimic compound, manganese(III) meso-tetrakis-(N-(2-aminoethyl)pyridinium-2-yl) porphyrin (iSODm), was synthesized to covalently attach to the neural probe surfaces. This new compound showed high catalytic superoxide scavenging activity. In microglia cell line cultures, the iSODm coating effectively reduced superoxide production and altered expression of iNOS, NADPH oxidase, and arginase. After 1 week of implantation, iSODm coated electrodes showed significantly lower expression of markers for oxidative stress immediately adjacent to the electrode surface, as well as significantly less neurons undergoing apoptosis. STATEMENT OF SIGNIFICANCE: One critical challenge in the translation of neural electrode technology to clinically viable devices for brain computer interface or deep brain stimulation applications is the chronic degradation of the device performance due to neuronal degeneration around the implants. One of the key mediators of inflammation and neuronal degeneration is reactive oxygen and nitrogen species released by injured neurons and inflammatory microglia. This research takes a biomimetic approach to synthesize a compound having similar reactivity as superoxide dismutase, which can catalytically scavenge reactive oxygen and nitrogen species, thereby reducing oxidative stress and decreasing neuronal degeneration. By immobilizing the compound covalently on the surface of neural implants, we show that the neuronal degeneration and oxidative stress around the implants is significantly reduced.

Characterizations of intracellular copper/zinc superoxide dismutase from yellow drum (Nibea albiflora, Richardson 1846) and its gene expressions under the ammonia/nitrite stress.

Intracellular copper/zinc superoxide dismutase (icCuZnSOD) is a member of superoxide dismutase family that is capable of catalyzing the superoxide radicals into either hydrogen peroxide (H2O2) or ordinary molecular oxygen (O2). Unlike mammals, the study of icCuZnSOD in aquatic animals is still in the infancy stage. Here, we identified the cDNA of na-iccuznsod from yellow drum (Nibea albiflora, Richardson 1846) and obtained its fusion protein for the first time. The mRNA expressions of na-iccuznsod were investigated in different tissues, and the dominant distribution was found in head-kidney, followed by brain, liver, heart, and gill. The effects of ammonia-N/nitrite-N on the mRNA expressions of na-iccuznsod were investigated. Na-iccuznsod transcription levels showed a general tendency of an initial up-regulation followed by a down-regulation in liver, gill, and head-kidney when yellow drum were exposed to ammonia-N/nitrite-N at the lethal concentration 50 at 96 h post-treatment, suggesting the important role of Na-icCuZnSOD in eliminating reactive oxygen species (ROS) induced by ammonia-N/nitrite-N. In addition, the characteristics of Na-icCuZnSOD protein and its comparative analysis with Na-ecCuZnSOD were investigated. Na-icCuZnSOD protein showed high enzyme stabilities over a wide range of temperature (10 to 60 °C) and pH (4.9 to 11.0), indicating its broad in vitro applications in many industries. Furthermore, the comparative analysis of Na-icCuZnSOD and Na-ecCuZnSOD gives a new perspective for the study of their structure-function relationship. Collectively, the present study will advance our understanding of the toxicity of ammonia-N/nitrite-N on yellow drum through testing the mRNA expression of iccuznsod gene, and broaden our knowledge of the protein characteristics of icCuZnSOD from fish.

Alpha lipoic acid supplementation improved antioxidant enzyme activities in hemodialysis patients.

Background: Cardiovascular disease (CVD) is the main cause of death in hemodialysis (HD) patients and oxidative stress is an important risk factor for CVD. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) are primary antioxidant enzymes in human cells acting against toxic reactive oxygen species (ROS) and their reduced activity may contribute to oxidative disorders in HD patients. Alpha lipoic acid (ALA) as a potent strong antioxidant may affect these enzymes. Objective: We examined the effects of ALA supplementation on antioxidant enzyme activities in HD patients. Method: In this double-blinded, randomized clinical trial, 63 HD patients (43 males and 20 females; age range: 22-79 years) were assigned into the ALA group (n: 31), receiving a daily dose of ALA (600 mg), or a control group (n: 32), receiving placebo for 8 weeks. Body mass index (BMI), antioxidant enzymes, albumin (Alb) and hemoglobin (Hb) were determined before and after intervention. Results: At baseline, the mean blood activities of SOD, GPx, and CAT in ALA group were 1032±366, 18.9±5.09 and 191±82.7 U/gHb which increased at the end of study to 1149±502, 19.1±7.19 and 208±86.6 U/gHb respectively. However, only the increase of SOD was statistically significant in comparison with placebo group (P = 0.04). The mean levels of Alb, Hb, weight and BMI were not significantly changed in study groups (P>0.05). Conclusion: ALA may be beneficial for HD patients by increasing the activity of antioxidant enzymes; however, further studies are needed to achieve precise results.

Protective effects of garlic extract against hematological alterations, immunosuppression, hepatic oxidative stress, and renal damage induced by cyclophosphamide in rats.

Cyclophosphamide is an alkylating agent widely used as anticancer drug, reported to exert cytotoxic effects attributed to oxidative stress. Therefore, this study aimed to explore the protective effect of ethanolic extract of garlic (EEG) against cyclophosphamide (Cyp)-induced hematological disturbance and immunosuppressive and hepatotoxic effects. Forty male Wistar albino rats were randomized into four equal groups: the normal control one, the Cyp-treated group (50 mg/kg BW/IM, once weekly), the EEG-treated group (300 mg/kg BW, orally, daily), and the Cyp & EEG group. All rats received their relevant treatments for four consecutive weeks. This study revealed that Cyp significantly decreased erythrocyte count, hemoglobin (Hb), packed cell volume (PCV), and total leukocyte and lymphocyte counts. However, the counts of neutrophils, eosinophils, and toxic neutrophils were elevated. Additionally, hepatic malondialdehyde (MDA) and levels of liver and renal biomarkers were significantly elevated in the Cyp-treated group. Otherwise, hepatic catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD), and serum total antioxidant capacity (TAC) were significantly lower than the control rats. Furthermore, Cyp significantly reduced whole blood respiratory burst activity (NBT), serum lysozyme and bactericidal activities, interlukin-12 (IL-12), and interferon-γ. In contrast, the levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interlukin-1ß (IL-1ß) were elevated. Additionally, Cyp induced hepatic and renal histopathological alterations. Data in the present study demonstrated that EEG has immunomodulatory and antioxidant effects and has the ability to diminish the alterations induced by Cyp.

Cu/ZnSOD always responded stronger and rapider than MnSOD in Lymantria dispar larvae under the avermectin stress.

Metalloenzyme SODs play important roles in insects dealing with environmental stress. Here, we cloned the Cu/ZnSOD (LdCZS) and MnSOD (LdMS) mRNA of Lymantria dispar by rapid amplification of cDNA ends (RACE). Afterwards their expression patterns were detected by quantitative real-time polymerase chain reaction (qPCR) after bioinformatic analysis. We found that both LdCZS and LdMS were widely detected in all gypsy moth larvae and all five tissues that we analyzed, and both of them were up-regulated after larvae were fed with avermectin of sublethal concentration and LC10. The LdCZS expression value are always higher than LdMS after treating with avermectin of sublethal concentrations. In addition, temporal expression profile in avermectin treated larvae showed that LdCZS expressed highest at 2nd hour, and LdMS expressed highest at 6th hour. The cuticulas transcribed LdCZS and LdMS significantly higher than heads, fat bodies, Malpighian tubes, and midguts after spraying avermectin of sublethal concentration. These results suggested that both Cu/ZnSOD and MnSOD are important antioxidant enzymes in L. dispar defensing against pesticide stress, and LdCZS always responded rapider and stronger than LdMS.

CuZnSOD and MnSOD from freshwater planarian Dugesia japonica: cDNA cloning, mRNA expression and enzyme activity in response to environmental pollutants.

As an important antioxidant enzyme, the superoxide dismutase (SOD) can protect aerobic organisms from oxidative damage through catalyzing the dismutation of superoxide into hydrogen peroxide and oxygen. The SODs have been cloned in some species and their dynamic expression or enzymatic activity in response to environmental stressors were investigated. In the current study, the full-length cDNA of two SODs from freshwater planarian Dugesia japonica were firstly cloned (named as DjCuZnSOD and DjMnSOD, respectively). The complete cDNA of DjCuZnSOD consists of 661 nucleotides encoding 186 amino acids while the 765 bp DjMnSOD encodes a polypeptide of 226 residues. Sequence analysis and multiple alignment showed that DjCuZnSOD possesses two CuZnSOD family signature motifs and an N-terminal signal peptide suggesting it is an extracellular secretory protein. DjMnSOD possesses the MnSOD family signature sequence and is predicted to be located in mitochondrion with a mitochondrial targeting sequence. Phylogenetic analysis based on CuZnSOD and MnSOD orthologs from representative species further verified that DjCuZnSOD is an extracellular CuZnSOD while DjMnSOD is a mitochondrial MnSOD. For the purpose of studying their potential role against environmental pollutants, D. japonica were exposed to glyphosate or 1-decyl-3-methylimidazolium bromide ([C10mim]Br), and the mRNA expression levels of DjCuZnSOD and DjMnSOD along with total SOD activity were measured. The results showed that DjCuZnSOD exhibited more sensitive expression profiles in response to environmental pollutants in contrast with DjMnSOD, and the total SOD activity in response to both pollutants was more related to the expression level of DjCuZnSOD than to DjMnSOD, indicating that the mRNA expression of CuZnSOD would be a more sensitive biomarker than MnSOD in monitoring the pollution of aquatic environment and CuZnSOD might play more important role than MnSOD in eliminating superoxide anions caused by pollutants in D. japonica.

Microwave-assisted extraction releases the antioxidant polysaccharides from seabuckthorn (Hippophae rhamnoides L.) berries.

Seabuckthorn berries are rich in various bioactive components and used as a traditional medicine for a long time. Until now, little information is available for the extraction of polysaccharides from seabuckthorn berries (PSB) by linking antioxidant activity and microwave power. In this study, microwave-assisted extraction, characterization, in vitro and in vivo antioxidant activities of PSB were explored. The maximum PSB extraction yield of 0.264±0.005% was obtained under the optimal conditions as follows: microwave power 600W, extraction time 6min, liquid to material ratio 10: 1mL/g, and extraction temperature 85°C. Meanwhile, effects of microwave power on antioxidant activity of PSB was investigated and found that microwave at power of 600W can facilitate the release of antioxidant PSB in a high yield. The main monosaccharides of PSB were Rha, Man, Glu, and Gal at a molar ratio of 1.00: 6.89: 1.62: 13.52, UV and FT-IR analysis coupled with molecular weight determination further indicated that PSB is a polydisperse polysaccharide. Moreover, PSB obtained under the optimal conditions equally exerted in vivo antioxidant activity through decreasing malonaldehyde and protein carbonyls and increasing superoxide dismutase and glutathione.

Targeting mitochondrial dysfunction and oxidative stress in heart failure: Challenges and opportunities.

Mitochondrial dysfunction characterized by impaired bioenergetics, oxidative stress and aldehydic load is a hallmark of heart failure. Recently, different research groups have provided evidence that selective activation of mitochondrial detoxifying systems that counteract excessive accumulation of ROS, RNS and reactive aldehydes is sufficient to stop cardiac degeneration upon chronic stress, such as heart failure. Therefore, pharmacological and non-pharmacological approaches targeting mitochondria detoxification may play a critical role in the prevention or treatment of heart failure. In this review we discuss the most recent findings on the central role of mitochondrial dysfunction, oxidative stress and aldehydic load in heart failure, highlighting the most recent preclinical and clinical studies using mitochondria-targeted molecules and exercise training as effective tools against heart failure.

Purification and properties of Manganese Superoxide Dismutase (MnSOD) from Tamarix aphylla L.

Superoxide dismutase (SOD) of the Tamarix aphylla leaves were detected at optimum conditions that collected in April, May and June. Results indicated the specific activity in the crude extract reaching to 36.76 unit/ mg protein. Crude SOD was purified by several techniques, precipitation with ammonium sulfate (50-75) %, Ion exchange chromatography using DEAE-cellulose and two steps of size exclusion chromatography on sephacryl S-200 column. The obtained specific activity (310 unit/mg protein) and purification fold 7.91. The purified enzyme revealed one band by SDS-polyacrylamide gel electrophoresis with molecular mass 85.703 kDa. while 89.125 kDa by Sephacryl S-200. The optimal pH and temperature for enzyme activity were 7.5, and 50ºC respectively. EDTA, SDS and NaN3 reduced activity, contrariwise of H2O2 and KCN, pointed to the studied SOD is MnSOD. Michalis constant Km and maximum velocity Vmax values were 0.016 mM and 55.86 mM/min, respectively by using Pyrogallol as substrate. According to the results, we conclude Tamarix aphylla produce MnSOD which can have purified by serial purification techniques for better activity and characterized for further studies.