Copper-zinc Superoxide Dismutase Activity Research Articles

Low protein diet influences mineral absorption and utilization in medium-growing yellow-feathered broilers from 1 to 30 days of age

Reduced-protein diet can save protein ingredients and reduce nitrogen (N) losses. However, the effect of low protein diet on the mineral uptake and utilization in broilers needs to be explored. The aim of this study was to investigate the effect of low-protein diet on the growth performance, N deposition, mineral contents in serum, tissues and excreta, and the activities and gene expression of related enzymes in tissues of medium-growing yellow-feathered broilers, so as to elucidate the relationship between dietary protein level and the absorption and utilization of minerals in broilers. A total of 72 1-d-old Spotted-Brown male broilers were randomly allotted to 1 of 2 treatments with 6 replicate cages of 6 birds per cage for each treatment. The dietary crude protein (CP) levels for the two treatments were 21 % (the control treatment) and 19 % (low protein treatment), respectively. The experimental period was 30 d. The results showed that no differences (P > 0.05) were detected in average daily gain, average daily feed intake and feed: gain ratio of broilers during 1 to 30 d between the two treatments. However, low protein intake increased (P < 0.05) N retention rate, serum P, Cu and Mn, and excreta Cu, Mn and Zn, and decreased (P < 0.05) liver P and excreta P. In addition, birds fed low protein diet had higher (P < 0.05) manganese superoxide dismutase, and total superoxide dismutase activities in liver, and total antioxidant capacity and malondialdehyde content in heart, and lower (P < 0.05) copper-zinc superoxide dismutase (CuZnSOD) and succinate dehydrogenase activities in liver and CuZnSOD mRNA level in heart. In conclusion, the reduction of dietary CP content from 21 % to 19 % improved N retention, the absorption of P, Cu and Mn, as well as the antioxidant ability of liver and heart, and influenced metabolic utilization of P, Cu, Zn, Fe and Mn in medium-growing yellow-feathered broilers from 1 to 30 d of age.

In vitro anticancer and antimicrobial activities of copper-zinc superoxide dismutase purified from Cellana rota snail

In vitro anticancer and antimicrobial activities of copper-zinc superoxide dismutase purified from Cellana rota snail

Mannan oligosaccharides alleviate oxidative injury in the head kidney and spleen in grass carp (Ctenopharyngodon idella) via the Nrf2 signaling pathway after Aeromonas hydrophila infection

BackgroundMannan oligosaccharides (MOS) are recommended as aquaculture additives owing to their excellent antioxidant properties. In the present study, we examined the effects of dietary MOS on the head kidney and spleen of grass carp (Ctenopharyngodon idella) with Aeromonas hydrophila infection.MethodsA total of 540 grass carp were used for the study. They were administered six gradient dosages of the MOS diet (0, 200, 400, 600, 800, and 1,000 mg/kg) for 60 d. Subsequently, we performed a 14-day Aeromonas hydrophila challenge experiment. The antioxidant capacity of the head kidney and spleen were examined using spectrophotometry, DNA fragmentation, qRT-PCR, and Western blotting.ResultsAfter infection with Aeromonas hydrophila, 400–600 mg/kg MOS supplementation decreased the levels of reactive oxygen species, protein carbonyl, and malonaldehyde and increased the levels of anti-superoxide anion, anti-hydroxyl radical, and glutathione in the head kidney and spleen of grass carp. The activities of copper-zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione S-transferase, glutathione reductase, and glutathione peroxidase were also enhanced by supplementation with 400–600 mg/kg MOS. Furthermore, the expression of most antioxidant enzymes and their corresponding genes increased significantly with supplementation of 200–800 mg/kg MOS. mRNA and protein levels of nuclear factor erythroid 2-related factor 2 also increased following supplementation with 400–600 mg/kg MOS. In addition, supplementation with 400–600 mg/kg MOS reduced excessive apoptosis by inhibiting the death receptor pathway and mitochondrial pathway processes.ConclusionsBased on the quadratic regression analysis of the above biomarkers (reactive oxygen species, malondialdehyde, and protein carbonyl) of oxidative damage in the head kidney and spleen of on-growing grass carp, the recommended MOS supplementation is 575.21, 557.58, 531.86, 597.35, 570.16, and 553.80 mg/kg, respectively. Collectively, MOS supplementation could alleviate oxidative injury in the head kidney and spleen of grass carp infected with Aeromonas hydrophila.

Roles of the Zinc Ion and Water Molecule in the Active Site of the Copper-Zinc SOD Catalyst

In this work, we study the effect of a water molecule and a zinc ion on the catalytic activity of copper-zinc superoxide dismutase by computer simulation at the level of density functional theory using the PBE functional and the def2-SVPD and def2-TZVPD basis sets. Assessment is carried out in two directions. The first is a comparison of the main characteristics of electron transfer according to Marcus in the presence and absence of a water molecule in the active site. The second is the topological analysis of the electron density of the ligand environment of the copper ion according to Bader. It has been found that the presence of a water molecule and a zinc ion next to a copper ion has little effect on the primary stage of catalysis, the reduction of the copper ion. However, their presence significantly affects the course of the second stage of the catalytic cycle in the oxidation of copper. The water molecule is involved as a proton carrier. It may be present next to the copper ion during primary electron transfer. The water molecule leaves the first coordination sphere of copper after the initial electron transfer; otherwise, it forms a strong bond with the nitrogen atom, interrupting the electron transfer, according to the topological analysis. The presence of a water molecule near copper significantly impairs the secondary electron transfer, and the catalytic cycle is generally blocked.

Oxidative stress and impaired insulin secretion in cystic fibrosis pig pancreas

Cystic fibrosis-related diabetes (CFRD) is one the most common comorbidities in cystic fibrosis (CF). Pancreatic oxidative stress has been postulated in the pathogenesis of CFRD, but no studies have been done to show an association. The main obstacle is the lack of suitable animal models and no immediate availability of pancreas tissue in humans. In the CF porcine model, we found increased pancreatic total glutathione (GSH), glutathione disulfide (GSSG), 3-nitrotyrosine- and 4-hydroxynonenal-modified proteins, and decreased copper zinc superoxide dismutase (CuZnSOD) activity, all indicative of oxidative stress. CF pig pancreas demonstrated increased DHE oxidation (as a surrogate marker of superoxide) in situ compared to non-CF and this was inhibited by a SOD-mimetic (GC4401). Catalase and glutathione peroxidase activities were not different between CF and non-CF pancreas. Isolated CF pig islets had significantly increased DHE oxidation, peroxide production, reduced insulin secretion in response to high glucose and diminished secretory index compared to non-CF islets. Acute treatment with apocynin or an SOD mimetic failed to restore insulin secretion. These results are consistent with the hypothesis that CF pig pancreas is under significant oxidative stress as a result of increased O2●− and peroxides combined with reduced antioxidant defenses against reactive oxygen species (ROS). We speculate that insulin secretory defects in CF may be due to oxidative stress.

Zinc alleviates the heat stress of primary cultured hepatocytes of broiler embryos via enhancing the antioxidant ability and attenuating the heat shock responses.

Zinc (Zn) has been shown to attenuate the adverse effects of heat stress on broilers, but the mechanisms involving this process remain unclear. We aimed to investigate possible protective mechanisms of Zn on primary cultured hepatocytes of broiler embryos subjected to heat stress. Three experiments were conducted. In Exp. 1, hepatocytes were treated with 0, 50, 100, 200, or 400 μmol/L added Zn as inorganic Zn sulfate (iZn) for 12, 24 or 48 h. In Exp. 2, cells were exposed to 40 °C (a normal temperature [NT]) and 44 °C (a high temperature [HT]) for 1, 2, 4, 6, or 8 h. In Exp. 3, cells were preincubated with 0 or 50 μmol/L Zn as iZn or organic Zn lysine chelate (oZn) for 8 h under NT, and then incubated with the same Zn treatments under NT or HT for 4 or 6 h. The biomarkers of antioxidative status and heat stress in cells were measured. The results in Exp. 1 indicated that 50 μmol/L Zn and 12 h incubation were the optimal conditions for increasing antioxidant ability of hepatocytes. In Exp. 2, the 4 or 6 h incubation under HT was effective in inducing heat shock responses of hepatocytes. In Exp. 3, HT elevated (P < 0.01) malondialdehyde content and expressions of heat shock protein 70 (HSP70) mRNA and protein, as well as HSP90 mRNA. However, Zn supplementation increased (P < 0.05) copper zinc superoxide dismutase (CuZnSOD) activity and metallothionein mRNA expression, and effectively decreased (P < 0.05) the expressions of HSP70 mRNA and protein, as well as HSP90 mRNA. Furthermore, oZn was more effective (P < 0.05) than iZn in enhancing CuZnSOD activity of hepatocytes under HT. It was concluded that Zn (especially oZn) could alleviate heat stress of broiler hepatocytes via enhancing their antioxidant ability and attenuating heat shock responses.

Concentration/activity of superoxide dismutase isozymes and the pro-/antioxidative status, in context of type 2 diabetes and selected single nucleotide polymorphisms (genes: INS, SOD1, SOD2, SOD3) – Preliminary findings

The alterations in concentration/activity of superoxide dismutase isozymes in the context of type 2 diabetes or obesity are well-described. Moreover, many hereditary factors, including single-nucleotide polymorphisms (SNPs) of genes for coding insulin, insulin receptors, or insulin receptor substrates (INS, INSR, IRS1, IRS2) or superoxide dismutase isozymes (SOD1, SOD2, SOD3), have been linked with the incidence of obesity and diabetes. However, the underlying changes in the plasma concentration/activity of superoxide dismutase isozymes and their potential connection with the said hereditary factors remain unexplored. Previously, we have observed that the plasma concentration/activity of superoxide dismutase isozymes differs in the context of obesity and/or rs2234694 (SOD1) and rs4880 (SOD2) and that the concentrations of SOD1, SOD2, SOD3 are correlated with each other. Intersexual variability of SOD1 concentration was detected regardless of obesity. In this study, the variability of concentration/activity of superoxide dismutase isozymes in plasma is considered in the context of type 2 diabetes and/or SNPs: rs2234694 (SOD1), rs5746105 (SOD2), rs4880 (SOD2), rs927450 (SOD2), rs8192287 (SOD3). Genotypic variability of SNP rs3842729 (INS), previously studied in the context of insulin-dependent diabetes, is investigated in terms of selected clinical parameters associated with type 2 diabetes. This study revealed higher SOD1 concentration in diabetic men compared to women, and extremely high SOD1 concentration, higher total superoxide dismutase, and copper-zinc superoxide dismutase activity, and lower superoxide dismutase and copper-zinc superoxide dismutase activity (when adjusted for the concentration of SODs) in the diabetic group regardless of sex. Multiple logistic regression, applied to explore possible links between the studied SNPs and other factors with the odds of type 2 diabetes or obesity, revealed that the genotypic variability of rs4880 (SOD2) could affect these odds, supporting the findings of several other studies.

Protein dynamics of [Cu-Zn] superoxide dismutase (SOD1): How protein motions at the global and local levels impact the reactivity of SOD1

This work explores the pivotal role that protein mobility plays in facilitating the catalytic activity of Copper-Zinc superoxide dismutase (SOD1). Through both localized active site distortions and correlated domain movement, these motions enable the enzyme to adopt the conformations necessary to achieve both substrate delivery and efficient catalytic transformation. Structural and computational studies of a biomimetic model complex are used to probe the localized interactions between substrate and secondary sphere residues that play a role in guiding substrate to the active site, as well as facilitating the conformational changes necessary for substrate turnover. Normal mode analysis (NMA) of SOD1 demonstrates how collective domain motion influences key residues of the electrostatic loop (ESL), guiding substrate to the active site and facilitating the delivery of the conserved water network necessary for proton transfer.

Antioxidant status and cytogenetic damage in hospital workers occupationally exposed to low dose ionizing radiation

The aim of the present study was to assess the oxidative stress level and chromosomal damage induced by occupational exposure to low dose ionizing radiation (LDIR). Two hundred and eighteen hospital workers occupationally exposed to LDIR were included in this study, along with 118 healthy age- and gender-comparable controls. Occupational dosimetry records were collected over the last year and revealed that the accumulated annual dose for each hospital worker was below the permissible limit of the International Commission on Radiological Protection (ICRP). The individuals’ oxidative and antioxidative status were determined by measuring the activities of copper zinc-superoxide dismutase (CuZn-SOD), glutathione peroxidase (GSH-Px), catalase (CAT) enzymes, and the levels of malondialdehyde (MDA) in erythrocytes. The effect of radiation on chromosomal integrity was measured by the frequency of micronuclei (MN) formation using the cytokinesis block technique. Our results showed that the activities of CuZn-SOD and CAT enzymes and MDA levels observed in the hospital workers were higher than those in the controls (p < 0.05). We did not find significant difference in GSH-Px enzyme activity between the two groups (p = 0.247). A higher frequency of MN was found in exposed groups than in the controls [3(1–5) ‰ versus 2(0.75–4) ‰; p<0.001]. The difference was significant for males (p = 0.012), but not females (p = 0.14). Multiple linear regression analysis showed differences in the oxidant activities and MN frequency between hospital workers and controls adjusted for age, gender, smoking status and drinking status. Correlation analysis indicated that the frequency of MN was positively associated with MDA levels (p < 0.05). Altogether, these results support the detrimental effects of chronic low dose radiation in humans, which involves the induction of oxidative stress and chromosomal damage.

Effect of dietary zinc pectin oligosaccharides chelate on growth performance, enzyme activities, Zn accumulation, metallothionein concentration, and gene expression of Zn transporters in broiler chickens1.

This study was to investigate the effect of zinc pectin oligosaccharides chelate (Zn-POS) on growth performance, serum enzyme activities, tissue zinc accumulation, metallothionein (MT) concentrations, and gene expression of zinc transporters (ZnT) in broilers. Five hundred forty 1-d-old Arbor Acres broiler chicks were randomly assigned to 5 dietary groups with 6 replicates of 18 birds per replicate. The diets were formulated with the same supplemental Zn level (80 mg/kg diet) but different amount of the Zn-POS: 0, 200, 400, 600, and 800 mg Zn-POS/kg diet. ZnSO4 was used to adjust to the desired amount of the Zn (80 mg/kg) in the Zn-POS diets. Broilers were fed with the experimental diets for 42 d including the starter (days 1 to 21) and grower (days 22 to 42) phases. Our results showed that dietary supplementation of Zn-POS linearly and quadratically increased (P < 0.05) the average daily gain and gain-to-feed ratio during 22 to 42 d and 1 to 42 d as well as body weight on day 42, whereas reduced (P < 0.05) the sum of mortality and lag abnormalities in broilers on day 42. Besides, serum alkaline phosphatase and copper-zinc superoxide dismutase activities increased (P < 0.05) linearly and quadratically in response to dietary Zn-POS supplemental level on day 42. Dietary Zn-POS supplementation increased Zn accumulation in serum (linear, P < 0.05), liver (linear, P < 0.05), and pancreas (linear and quadratic, P < 0.05). In addition, Zn-POS supplementation linearly and quadratically increased (P < 0.01, P < 0.05, respectively) MT concentrations in liver and pancreas of broilers. Pancreatic mRNA levels of MT, ZnT-1, and ZnT-2 increased (P < 0.05) linearly and quadratically, and the mRNA expression of metal response element-binding transcription factor-1 increased linearly (P < 0.05), in response to dietary Zn-POS supplementation. In conclusion, supplementation of Zn-POS in the diet increases Zn enrichment in the metabolic organs such as liver and pancreas and promotes productive performance in broilers.

The role of silver ions in the regulation of the senescence process in Triticum aestivum.

The control of senescence has economic importance due to its effects on parameters such as herbal product quality and shelf life. This study is on the control of induced senescence in Triticum aestivum L. 'Gün-91' plants with silver nitrate (AgNO3) treatments. It was observed that some changes that occurred with dark and indole-1-acetic acid (IAA) treatments could be reduced with AgNO3 treatments. After dark-induced senescence, it was observed in plants that seedling length, relative water content (RWC), chlorophyll, β-carotene, xanthophylls, total antioxidant capacity, soluble phenol, total soluble protein, catalase (CAT), total superoxide dismutase (SOD), copper-zinc superoxide dismutase (Cu/Zn-SOD) activities, and expression of genes encoding these enzymes declined. After IAA treatments, seedling length, RWC, chlorophyll, β-carotene, xanthophylls, total antioxidant capacity, soluble phenolics, and soluble protein levels declined, whereas activities of CAT, total SOD, and Cu/Zn-SOD enzymes and expression of Cu/Zn-SOD and CAT genes increased. AgNO3 (200 mg L-1 ) applied by spraying onto leaves led to an increase in seedling length, RWC, chlorophyll, β-carotene, xanthophylls, total antioxidant capacity, soluble phenolics, soluble protein levels, and expression of Cu/Zn-SOD, CAT genes, CAT, SOD, and Cu/Zn-SOD enzyme activities compared to controls. Findings obtained from this study showed that the senescence process was related to changes in the levels of antioxidant compounds and enzymes. It was defined that the role of silver ions in slowing senescence was related to antioxidant defense capacity.

Effects of Alpha-Lipoic Acid Supplementation on Oxidative Stress Status in Patients with Non-Alcoholic Fatty Liver Disease: A Randomized, Double Blind, Placebo-Controlled Clinical Trial

Background: Several mechanisms have been suggested to explain the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and its progression, one of which is increased oxidative stress. Objectives: This study aimed to evaluate the effect of alpha-lipoic acid (ALA) supplementation on anthropometric indices, dietary intake and oxidative stress-related parameters in obese patients with NAFLD. Methods: In this double-blind, placebo-controlled trial, 50 NAFLD patients were assigned to two groups of receiving 1200 mg ALA (two 600 mg capsules of ALA) and placebo (two 600 mg capsules of placebo) for 12 weeks. Serum liver enzymes, malondialdehyde (MDA) level, total antioxidant status (TAS), and the activities of copper-zinc superoxide dismutase (Cu/Zn-SOD) and glutathione peroxidase (GSH-Px) were assessed at baseline and after 12 weeks of intervention. Results: Serum concentrations of liver enzymes decreased significantly in the ALA group (P < 0.05 for all), while a noticeable decline was observed for alanine aminotransferase (ALT) in the placebo group (32.5 ± 18.9 vs. 25.9 ± 11.2; P = 0.034). Nonetheless, there were no significant differences between the study groups concerning serum liver enzymes concentrations post-intervention. Although ALA supplementation significantly reduced the serum concentration of MDA (2.52 ± 0.35 vs. 2.77 ± 0.49; P < 0.040) and increased serum TAS (1.73 ± 0.55 vs. 1.52 ± 0.34; P < 0.048), other oxidative stress-related parameters such as Cu/Zn-SOD and GSH-Px activities were not affected. Conclusions: These findings suggest that daily supplementation of 1200 mg alpha-lipoic acid (ALA) for 12 weeks improves oxidative stress markers in patients with nonalcoholic fatty liver disease (NAFLD) and it could be considered as adjunctive therapy for the prevention of NAFLD progression.

Effects of dietary arginine on intestinal antioxidant status and immunity involved in Nrf2 and NF-κB signaling pathway in juvenile blunt snout bream, Megalobrama amblycephala

The present study assessed the effects of dietary arginine on intestinal antioxidant status and immunity involved in Nrf2 and NF-κB signaling pathway in juvenile blunt snout bream. Fish were fed three practical diets with graded arginine levels (0.87%, 1.62% and 2.70%) for 8 weeks. Compared with the control group (0.87%), the counts of white blood cell (WBC), red blood cell (RBC) and hemoglobin (HGB) content were significantly improved at dietary arginine levels of 1.62% (P<0.05). Plasma albumin (ALB) levels and alkaline phosphatase (ALP) activities were significantly improved at dietary arginine levels of 1.62% and 2.70% (P < 0.05). Alanine transaminase (ALT) activity was decreased in fish fed with 1.62% dietary arginine level (P<0.05). Plasma glutathione peroxidase (GPx) activities, copper-zinc superoxide dismutase (Cu/Zn-SOD) activities, total antioxidant capacity (T-AOC) activities and glutathione (GSH) levels were significantly increased at dietary arginine levels of 1.62% and 2.70% (P<0.05). Plasma total superoxide dismutase (T-SOD) activities and catalase (CAT) activities were significantly improved in fish fed with 1.62% dietary arginine level. Significantly higher manganese superoxide dismutase (Mn-SOD) activity was observed in fish fed with 1.62% dietary arginine level compared with 2.70% dietary arginine level (P<0.05). 1.62% and 2.70% dietary arginine levels significantly lowered malondialdehyde (MDA) levels. The relative expression of nuclear factor erythroid 2-related factor 2 (Nrf2) was significantly increased in fish fed with 1.62% dietary arginine level, inversely, the relative expression of Kelch-like ECH-associated protein 1 (Keap1) showed a converse trend. 1.62% and 2.70% dietary arginine levels significantly improved the relative expressions of Cu/Zn-SOD, GPx and CAT. Furthermore, 2.70% dietary arginine level significantly lowered the relative expression of Mn-SOD compared with the control group and 1.62% dietary arginine levels. The relative expressions of Interleukin 1β (IL-1β), tumour necrosis factor-α (TNF-α) and nuclear factor-kappa B (NF-κB) were lowered in fish fed with 1.62% dietary arginine level. 1.62% and 2.70% dietary arginine levels significantly improved the relative expressions of transforming growth factor-β (TGF-β). Hematocrit (HCT), aspartate aminotransferase (AST) activities, interleukin 8 (IL-8) and interleukin 10 (IL-10) expressions were not significantly affected by the graded dietary arginine levels. These results suggest that the optimal dietary arginine level plays an important role in enhancing antioxidant and immune status to maintain the intestinal health of juvenile blunt snout bream.

Effects of oxidative stress induced by high dosage of dietary iron ingested on intestinal damage and caecal microbiota in Chinese Yellow broilers.

The objective of this trial was to test the effects of oxidative stress induced by a high dosage of dietary iron on intestinal lesion and the microbiological compositions in caecum in Chinese Yellow broilers. A total of 450 1-day-old male chicks were randomly allotted into three groups. Supplemental iron (0, 700 and 1,400mg/kg) was added to the basal diet resulting in three treatments containing 245, 908 and 1,651mg/kg Fe (measured value) in diet respectively. Each treatment consisted of six replicate pens with 25 birds per pen. Jejunal enterocyte ultrastructure was observed by transmission electron microscopy. The results showed that a high dosage of dietary iron induced oxidative stress in broilers. Dilated endoplasmic reticulum (ER), autophagosome formation of jejunal enterocytes and decreased villi were caused by this oxidative stress. Compared to the control, concentration of the malondialdehyde (MDA) in jejunal mucosa in the 908 and 1,651mg/kg Fe groups increased by 180% (p<.01) and 155% respectively (p<.01); activity of copper-zinc superoxide dismutase (Cu/ZnSOD) increased in jejunum (p<.01); and the concentration of plasma reduced glutathione (GSH) decreased by 34.9% (p<.01) in birds fed 1,651mg/kg Fe. Gene expression of nuclear factor, erythroid-derived 2-like 2 (Nrf2) and zonula occludens-1 (ZO-1), in the higher dietary Fe groups was enhanced (p<.05). Species of microbial flora in caecum increased caused by oxidative stress. The PCR-DGGE (denaturing gradient gel electrophoresis) dendrograms revealed different microbiota (65% similarity coefficient) between the control and iron-supplemented groups (p<.05). These data suggest high dosage of iron supplement in feed diet can induce oxidative stress in Chinese Yellow broilers, and composition of microbiota in the caecum changed. It implied there should be no addition of excess iron when formulating diets in Chinese Yellow broilers.

Effect of dietary supplementation of organic zinc on laying performance, egg quality and some biochemical parameters of laying hens

This study was conducted to evaluate the effects of zinc methionine (Zn-Met) supplementation on the performance, egg quality, antioxidant status and some biochemical parameters of blood serum in laying hens from 22 to 34weeks of age. A total of 120 Hisex Brown laying hens of 22-week-old were randomly allocated into five treatments with six cage replicates for each (four hens/replicate). Dietary treatments consisted of the basal diet with no Zn-Met supplementation (control group) and basal diet supplemented with 25, 50, 75 or 100mg Zn-Met/kg diet. No significant differences were observed on body weight, body weight gain or feed conversion ratio due to dietary Zn-Met supplementation. However, highly significant impact was observed on daily feed intake. Egg number, egg weight and egg mass were increased in the group fed diet supplemented with the highest level of Zn-Met (100mg/kg of diet) as compared to other groups. All egg quality traits were statistically (p>.05 or .01) affected as a response to dietary Zn-Met supplementation except egg shape index, shell percentage and yolk index. In comparison with the control group, dietary supplementation of 25, 50, 75 or 100mg Zn-Met/kg decreased serum triglyceride and LDL-cholesterol levels. Serum cholesterol level was increased with all dietary levels of Zn-Met in comparison with the control group. Dietary Zn-Met supplementation increased the serum content of zinc, where the highest values were recorded with 50 and 100mg Zn-Met/kg diet. Dietary Zn-Met levels did not affect the antioxidant indices in blood serum except for the activity of copper-zinc superoxide dismutase (Cu-Zn-SOD). The activity of Cu-Zn-SOD was increased with Zn-Met supplementations with no differences among supplemental zinc levels. It is concluded that dietary Zn-Met supplementation reduced serum triglyceride, LDL-cholesterol and increased Zn status and resulted in promoting antioxidant ability of laying hens, and the addition of 100mg Zn-Met/kg to layer diet was appropriate for improving the above parameters in addition to egg production indices and Haugh unit score.

Effects of Maternal Zinc Glycine on Mortality, Zinc Concentration, and Antioxidant Status in a Developing Embryo and 1-Day-Old Chick.

This study was conducted to investigate the effects of maternal zinc glycine (Zn-Gly) supplementation as an alternative for zinc sulfate (ZnSO4) on mortality, zinc (Zn) concentration, and antioxidant status in a developing embryo and 1-day-old chick. Six hundred 39-week-old broiler breeders were randomly assigned to 6 treatments, each treatment including 5 replicates with 20 birds each. Six treatments received a basal diet (control, 24mg Zn/kg diet) or a basal diet supplemented with ZnSO4 (80mg Zn/kg) or Zn-Gly (20, 40, 60, or 80mg Zn/kg), respectively. The experiment lasted for 8weeks after a 4-week pre-experiment with a basal diet. At the last week, 100 eggs per replicate were randomly collected for incubation. Compared with the control treatment, Zn supplementation decreased (P<0.05) embryo mortalities of the late stage and the whole period, increased (P<0.05) liver Zn concentration in the embryo of d9, d19, and 1-day-old chick, and improved (P<0.05) antioxidant status in the embryo of d19 and 1-day-old chick. Compared with the ZnSO4 treatment, 80mg Zn/kg Zn-Gly treatment significantly decreased (P<0.05) the late stage embryo mortality and increased (P<0.05) liver Zn concentration in the embryo of d9, d19, and 1-day-old chick. The 80mg Zn/kg Zn-Gly treatment significantly increased (P<0.05) copper-zinc superoxide dismutase activity in d19 embryo and 1-day-old chick, total superoxide dismutase activity in 1-day-old chick, and copper-zinc superoxide dismutase messenger RNA (mRNA) abundance of d9 embryo and 1-day-old chick than that in ZnSO4 treatment. The liver metallothionein concentration of the developing embryo and 1-day-old chick and its mRNA abundance of d19 embryo were also significantly increased (P<0.05) in the 80mg Zn/kg Zn-Gly treatment in comparison with ZnSO4 treatment. In conclusion, maternal Zn supplementation decreased embryo mortalities of the late stage and the whole period by increasing liver Zn concentration and antioxidant status in d19 embryo and 1-day-old chick, and 80mg Zn/kg from Zn-Gly treatment was the optimum choice.

In vivo EPR pharmacokinetic evaluation of the redox status and the blood brain barrier permeability in the SOD1G93A ALS rat model

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder affecting the motor pathways of the central nervous system. Although a number of pathophysiological mechanisms have been described in the disease, post mortem and animal model studies indicate blood-brain barrier (BBB) disruption and elevated production of reactive oxygen species as major contributors to disease pathology. In this study, the BBB permeability and the brain tissue redox status of the SOD1G93A ALS rat model in the presymptomatic (preALS) and symptomatic (ALS) stages of the disease were investigated by in vivo EPR spectroscopy using three aminoxyl radicals with different cell membrane and BBB permeabilities, Tempol, 3-carbamoyl proxyl (3CP), and 3-carboxy proxyl (3CxP). Additionally, the redox status of the two brain regions previously implicated in disease pathology, brainstem and hippocampus, was investigated by spectrophotometric biochemical assays. The EPR results indicated that among the three spin probes, 3CP is the most suitable for reporting the intracellular redox status changes, as Tempol was reduced in vivo within minutes (t1/2 =2.0±0.5min), thus preventing reliable kinetic modeling, whereas 3CxP reduction kinetics gave divergent conclusions, most probably due to its membrane impermeability. It was observed that the reduction kinetics of 3CP in vivo, in the head of preALS and ALS SOD1G93A rats was altered compared to the controls. Pharmacokinetic modeling of 3CP reduction in vivo, revealed elevated tissue distribution and tissue reduction rate constants indicating an altered brain tissue redox status, and possibly BBB disruption in these animals. The preALS and ALS brain tissue homogenates also showed increased nitrilation, superoxide production, lipid peroxidation and manganese superoxide dismutase activity, and a decreased copper-zinc superoxide dismutase activity. The present study highlights in vivo EPR spectroscopy as a reliable tool for the investigation of changes in BBB permeability and for the unprecedented in vivo monitoring of the brain tissue redox status, as early markers of ALS.

Carbonate Anion Radical Generated by the Peroxidase Activity of Copper-Zinc Superoxide Dismutase: Scavenging of Radical and Protection of Enzyme by Hypotaurine and Cysteine Sulfinic Acid.

Copper-zinc superoxide dismutase (SOD) is considered one of the most important mammalian antioxidant defenses and plays a relevant role due to its main function in catalyzing the dismutation of superoxide anion to oxygen and hydrogen peroxide. However, interaction between SOD and H2O2 produced a strong copper-bound oxidant (Cu(II)•OH) that seems able to contrast the self-inactivation of the enzyme or oxidize other molecules through its peroxidase activity. The bicarbonate presence enhances the peroxidase activity and produces the carbonate anion radical (CO3•-). CO3•- is a freely diffusible reactive species capable of oxidizing several molecules that are unwieldy to access into the reactive site of the enzyme. Cu(II)•OH oxidizes bicarbonate to the CO3•-, which spreads out of the binding site and oxidizes hypotaurine and cysteine sulfinic acid to the respective sulfonates through an efficient reaction. These findings suggest a defense role for sulfinates against the damage caused by CO3•- . The effect of hypotaurine and cysteine sulfinic acid on the CO3•--mediated oxidation of the peroxidase probe ABTS to ABTS cation radical (ABTS•+) has been studied. Both sulfinates are able to inhibit the oxidation of ABTS mediated by CO3•-. The effect of hypotaurine and cysteine sulfinic acid against SOD inactivation by H2O2 (~42% protection of enzyme activity) has also been investigated. Interestingly, hypotaurine and cysteine sulfinic acid partially avoid the H2O2-mediated SOD inactivation, suggesting that the two sulfinates may have access to the SOD reactive site and preserve it by reacting with the copper-bound oxidant. In this way hypotaurine and cysteine sulfinic acid not only intercept CO3•- which could move out from the reactive site and cause oxidative damage, but also prevents the inactivation of SOD.

Differences in seminal plasma and spermatozoa antioxidative systems and seminal plasma lipid and protein levels among boar breeds and hybrid genetic traits

The objectives of this study were to determine the influence of breed and hybrid genetic traits of boars on lipid and protein concentrations and antioxidative system variables in seminal plasma (SP) and spermatozoa and their correlations with semen quality variables. Semen samples from 27 boars: Swedish Landraces (SL), German Landraces (GL), Large Whites (LW), Pietrains (P) and Pig Improvement Company hybrids (PIC-hybrid), aged from 1.5 to 3 years old, were collected. SP was spectrophotometrically analyzed to determine total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triacylglycerol (TAG), total protein (TP), albumin, and zinc concentrations. The antioxidative system in SP and spermatozoa was established spectrophotometrically by determining total antioxidative status (TAS), total superoxide dismutase (TSOD) and glutathione peroxidase (GSH-Px) parameters, as well as copper-zinc superoxide dismutase (CuZnSOD) and manganese superoxide dismutase (MnSOD) activity in spermatozoa. The hybrid boars had higher (P<0.05) SP concentrations of: TC, LDL-C and TAG than P and GL; HDL-C than P, GL and SL; and TP than P and LW. PIC-hybrid had lower values (P<0.05) in spermatozoa of: TAS and CuZnSOD than SL; TSOD and GSH-Px than SL and P; and MnSOD than SL and LW. Differences in SP and spermatozoa antioxidative system variables and the significant differences in SP protein and lipid variables exist among boars of different breeds and hybrid. Novel data and observed differences in semen variables among boar breeds and hybrids and their correlations with semen quality parameters in this study could contribute to better assessment of boar semen quality.

Acute exercise stress promotes Ref1/Nrf2 signalling and increases mitochondrial antioxidant activity in skeletal muscle.

What is the central question of this study? How does acute exercise affect the redox effector factor-1 (Ref1) and nuclear factor erythroid 2-related factor 2 (Nrf2) signalling and its association with mitochondrial H(2)O(2) production and antioxidant capacity? What is the main finding and its importance? Ref1/Nrf2 signalling in skeletal muscles was activated by acute exercise, and this activation was correlated with increased mitochondrial H(2)O(2) content and antioxidant capacity (reduced glutathione and manganese superoxide dismutase). The finding indicates that the oxidative stress induced by acute exercise in skeletal muscle mitochondria is associated with the upregulation of Ref1/Nrf2 signalling and enhancement of antioxidant defense pathways. This mechanism may play a role in preventing cellular oxidative stress resistance during acute exercise. The molecular mechanism of exercise-induced oxidative stress and adaptive activation of antioxidant responses in skeletal muscle has not been fully elucidated. This study aimed to investigate the effect of acute exercise on redox effector factor-1 (Ref1) and nuclear factor erythroid 2-related factor 2 (Nrf2) signalling and associations with mitochondrial H(2)O(2) production and antioxidant mechanisms in skeletal muscles. Groups of male ICR/CD-1 mice were subjected to an acute exercise bout of different durations (45, 90, 120 or 150 min). Muscle tissues (gastrocnemius and quadriceps femoris) were harvested after exercise to measure mitochondrial manganese superoxide dismutase (MnSOD) and copper-zinc superoxide dismutase (CuZnSOD) activities, reduced glutathione (GSH) content and expression of Ref1/Nrf2 genes and Ref1/Nrf2 proteins. The acute exercise increased oxidative stress and activated Ref1/Nrf2 signalling in a time-dependent manner, with a linear correlation between the mitochondrial H(2)O(2) content and Ref1/Nrf2 expressions. The GSH content and MnSOD activity were also significantly increased, but CuZnSOD activity was not significantly affected. The findings indicate that the H(2)O(2) production induced by acute exercise in skeletal muscle mitochondria in the mouse is closely associated with upregulation of the Ref1/Nrf2 signalling pathway and enhancement of antioxidant defense components, including GSH and MnSOD. Activation of Ref1/Nrf2/antioxidant defense pathways may play a role in preventing cellular oxidative stress resistance during acute exercise.