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Selenium (Se) is an essential trace element for human health, but its nutritional supply is insufficient in large parts of the world. Mushrooms can be enriched in selenium and can serve as alternative and natural source of selenium supplementation. In the present study, two common mushroom species (Pleurotus ostreatus and Ganoderma lucidum), were enriched with two selenium compounds (selenite and selenate) to test their suitability as natural sources of selenium supplementation. Sharp differences in the the metabolic patterns of the fortified selenium were observed. Selenium was effectively metabolized in P. ostreatus but remained in inorganic form in G. lucidum. However, mushrooms extracts were effective in enhancing selenoprotein expression in cell lines. The present study highlights the importance of employing selenium speciation analysis with an element-selective technique to examine the metabolic products following mushroom fortification for nutritional purposes due to the different toxicological profile and bioavailability of different selenium biotransformation products.

Biostimulants contain substances that regulate the secondary metabolism of plants. In addition to stimulating plant growth and development, they activate physiological and biochemical functions that help mitigate salt stress in plants. The objective of this study was to evaluate the mitigating effect of a commercial biostimulant on proline content, total protein and antioxidant enzymatic activity of three varieties of basil subjected to salinity stress with sodium chloride (NaCl). The design used was completely randomized with a factorial arrangement. Factor A were the varieties (Napoletano, Nufar and Emily), factor B the NaCl concentrations (0, 50, 100 and 150 mM) and factor C, the doses of the biostimulant (0 and 0.5 mL L −1 ) with four repetitions. Proline content, total protein, and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activity were determined in leaves and roots. The results showed that basil varieties increased proline, CAT, SOD and GPX concentrations as NaCl concentrations were moderate to severe (100 and 150 mM). The plants treated with 0.5 mL L−1 of the biostimulant significantly increased the variables studied, even in the presence of NaCl stress, determining the mitigating action of the biostimulant by promoting greater antioxidant enzymatic activity and an increase in osmoregulatory substances., Los bioestimulantes contienen sustancias que regulan el metabolismo secundario de las plantas. Además de estimular el crecimiento y el desarrollo vegetal, activan funciones fisiológicas y bioquímicas que ayudan a mitigar el estrés salino en las plantas. El objetivo de este estudio fue evaluar el efecto mitigador de un bioestimulante comercial en el contenido de prolina, proteínas totales y actividad enzimática antioxidante de tres variedades de albahaca sometidas a estrés por salinidad con cloruro de sodio (NaCl). El diseño utilizado fue completamente al azar con arreglo factorial. El factor A fueron las variedades (Napoletano, Nufar y Emily), el factor B las concentraciones de NaCl (0, 50, 100 y 150 mM) y el factor C, las dosis del bioestimulante (0 y 0.5 mL L−1 ) con cuatro repeticiones. El contenido de prolina, proteínas totales y la actividad de superóxido dismutasa (SOD), catalasa (CAT) y glutatión peroxidasa (GPX) se determinaron en hojas y raíces. Los resultados mostraron que las variedades de albahaca aumentaron las concentraciones de prolina, CAT, SOD y GPX conforme las concentraciones de NaCl fueron de moderadas a severas (100 y 150 mM). Las plantas tratadas con 0.5 mL L−1 del bioestimulante, incrementaron significativamente las variables estudiadas, aún en presencia del estrés por NaCl, determinándose la acción mitigadora del bioestimulante al promover una mayor actividad enzimática antioxidante y un aumento de sustancias osmorreguladoras

Structural and regulatory requirements of mammalian spermatozoa in both development and function make them extremely unique cells. Looking at the complexity of spermatozoon structure and its requirements for both motility and quick breakdown within the post-fertilization environment, as well as its functional needs as an extremely streamlined cell with high energy requirements, demonstrate the high importance of oxidative-reductive processes. The oxidative state of the testis and epididymis during sperm development and maturation highly influences sperm structure, with a high dependence on disulfide bond formation, facilitated by thiol mediated processes. However, once functionally active, sperm transition to a new high-risk functional paradigm requiring low levels of reactive oxygen species (ROS) while also being highly susceptible to oxidative damage due to the high proportion of polyunsaturated fatty acids within the lipid bilayer of the plasmalemma and the lack of cytosolic antioxidant defenses. This chapter highlights how glutathione and thioredoxin systems mediate the oxidative environment of the male reproductive tract and facilitate the successful development, maturation and function of mammalian spermatozoa.

Background: In sepsis, neutrophil respiratory bursts participate in endothelium damage, the first step to multiple organ failure. In plasma two antioxidant selenoenzymes, which protect the endothelium, decrease: selenoprotein-P, and to a lesser extent glutathione peroxidase (GPX3). Sodium selenite (Na2SeO3) is a Se donor, but also an oxidant chemotherapy drug depending on its concentration. In a previous published study, Na2SeO3 continuous infusion in septic shock patients at a pharmacological dose of 4 mg1 Se/day on day-1, followed by a high nutritional dose of 1 mg Se/day during 9 days, showed no beneficial effect on weaning of catecholamine nor on survival. In this ancillary study, we report clinical and biological effects of such continuous infusion of Na2SeO3. Methods: This was a multicenter, placebo-controlled, double-blind study on 60 patients. Na2SeO3 or placebo in continuous infusion as described above. Evolution with time of plasma Se, selenoprotein-P, GPX3, Organ dysfunction (sequential organ failure assessment SOFA scores, including PaO2/FiO2, for respiratory failure, and plasma lactate) and quality of life at 6 months (by SF36 scores) were analyzed using two-way (time, treatment) non-parametric repeated-measures analysis of variance (Friedman test). Main Results: At baseline, plasma Se was about a quarter of reference values. From baseline to day-4 plasma Se, selenoprotein-P and GPX3 significantly increased by 3.9, 2.7 and 1.8 respectively in the Na2SeO3 group as compared with placebo and remained elevated by 2.3, 2.7 and 2.1 at day-14 respectively (p < 0.001). Na2SeO3 did not affect global and organ by organ SOFA Scores and plasma lactate concentration at day-1 and later up to day-14. The evolution of PaO2/FiO2 until day-14 was similar in the two groups. Quality of life in the surviving patients at 6 months was similar between the two groups. Conclusion: Continuous infusion of Na2SeO3 at 4 mg Se at day-1 seems to have neither beneficial nor toxic effec, SCOPUS: ar.j, info:eu-repo/semantics/published

Introduction. Glutathione peroxidases are selenoenzymes which have a crucial role in the protection of animals against oxidative stress. Materials and Methods. From September 2017 to April 2018, a group of eight red-eared sliders were admitted at the Clinic for Small Animals, Faculty of Veterinary Medicine, University of Belgrade for elective diagnostic celioscopy. The turtles were of unknown age, weight from 1.20 kg to 1.86 kg. The anesthesia protocol involved using ketamine and medetomidine, both at a low dosage (10 mg kg-1 and 0.1 mg kg-1, respectively) as induction, after which anesthesia was maintained using isoflurane at 3% (vapor setting) in 100% oxygen (0.5 L min-1). Medetomidine was reversed with atipamezole (0.2 mg kg-1), given intramuscularly. The elective celioscopy was performed according to standard protocols. One day prior to anesthesia, heparinized blood samples were taken using the subcarapacial venous plexus for venipuncture. The second sampling took place three hours after the anesthetics were administered. Results and Conclusions. GPx3 activity in the blood plasmas (n=8) was measured by the coupled test as described by Günzler et al. (1974). Data were tested for normality by the Shapiro-Wilk normality test and the groups were compared using a paired t-test. Blood plasma GPx3 activity was significantly higher (p=0.009) after a three-hour recovery period from inhalation anesthesia performed for elective diagnostic celioscopy, than before anesthesia. The measured post-anesthesia GPx3 activities were, on average, 80% higher than the measurements prior to anesthesia. It can be concluded that the statistically significant increase in the activity of plasma GPx3 from 91.02±36.05 mKat L-1 prior to anesthesia to 160.21±58.94 mKat L-1 three hours after anesthesia is due to the change in oxygen saturation. This is increased to 100% during the procedure, thus exposing the turtles to conditions of high oxygen saturation., Uvod. Glutation peroksidaze su selenoenzimi koji igraju ključnu ulogu u zaštiti životinja od oksidativnog stresa. Materijal i metode. Od septembra 2017. do aprila 2018. godine, grupa od osam crvenouhih kornjača je primljena na Kliniku za male životinje, Fakulteta Veterinarske Medicine, Univerziteta u Beogradu zbog izvođenja elektivne dijagnostičke celioskopije. Kornjače su bile nepoznate starosti, mase između 1,20 kg i 1,86 kg. Anastetički protokol je uključivao primenu ketamina (10 mg kg-1) i medetomidina (0.1 mg kg-1) za indukciju, oba u niskim dozama, nakon čega je anestezija održavana primenom izoflurana u koncentraciji od 3% (podešen na isparavanje) u 100% kiseoniku (0.5 L min-1). Dejstvo medetomidina je neutralizovano atipamezolom (0.2 mg kg-1), aplikovanim intramuskularno. Elektivna celioskopija je izvedena u skladu sa standardnim protokolima. Heparinizovani uzorci krvi su uzeti jedan dan pre uvođenja u anesteziju venepunkcijom iz subkarapacijalnog venskog pleksusa. Drugo uzorkovanje krvi je uzvršeno tri sata nakon administracije anestetika. Rezultati i zaključak. GPx3 aktivnost u krvnoj plazmi (n=8) je izmerena primenom kuplovane reakcije, kao što su opisali Günzler i sar. (1974). Normalna distribucija podataka je testirana pomoću Shapiro - Wilk testa normalnosti (p>0,05), a grupe su poređene koristeći t test za zavisne uzorke. Aktivnost GPx3 u krvnoj plazmi je bila značajno viša (p=0.009) u uzorcima uzetim nakon trosatnog perioda oporavka od inhalacione anestezije aplikovane radi izvođenja elektivne celioskopije, nego u uzorcima uzetim pre aplikovanja anestezije. Vrednosti GPx3 izmerene nakon anestezije bile su u proseku 80% više od vrednosti pre anestezije. Može se zaključiti da je statistički značajan porast u aktivnosti GPx3 u plazmi od 91.02±36.05 mKat L-1, pre anestezije do 160.21±58.94 mKat L-1, tri sata nakon anestezije uzrokovan promenom u saturaciji kiseonika. Tokom intervencije saturacija kiseonika se povećava i do 100% čime se kornjače uvode u us

The so-called peroxidatic cysteines and selenocysteines in proteins reduce hydroperoxides through a dual attack to the peroxide bond in a two-step mechanism. First, a proton dislocation from the thiol/selenol to a close residue of the enzymatic pocket occurs. Then, a nucleophilic attack of the anionic cysteine/selenocysteine to one O atom takes place, while the proton is shuttled back to the second O atom, promoting the formation of a water molecule. In this computational study, we use a molecular model of GPx to demonstrate that the enzymatic environment significantly lowers the barrier of the latter SN2 step. Particularly, in our Se-based model the energy barriers for the two steps are 29.82 and 2.83 kcal mol−1, both higher than the corresponding barriers computed in the enzymatic cluster, i. e., 21.60 and null, respectively. Our results, obtained at SMD-B3LYP-D3(BJ)/6-311+G(d,p), cc-pVTZ//B3LYP-D3(BJ)/6-311G(d,p), cc-pVTZ level of theory, show that the mechanistic details can be well reproduced using an oversimplified model, but the energetics is definitively more favorable in the GPx active site. In addition, we pinpoint the role of the chalcogen in the peroxide reduction process, rooting the advantages of the presence of selenium in its acidic and nucleophilic properties.

[EN] Feeding 3.9 and 6.7 mg Hg/kg (Se/Hg molar ratios of 0.8 and 0.4, respectively) for 14 days negatively affected Dicentrarchus labrax growth and total DNTB- and thioredoxin-reductase (TrxR) activities and the transcription of four redox genes (txn1, gpx1, txnrd3, and txnrd2) in the liver, but a diet with 0.5 mg Hg/kg (Se/Hg molar ratio 6.6) slightly increased both reductase activities and the transcription of txn1, gpx1, and txnrd2. Feeding 6.7 mg Hg/kg for 53 days downregulated the genes of the thioredoxin system (txn1, txnrd3, and txnrd2) but upregulated gpx1, confirming the previously proposed complementarity among the antioxidant systems. Substitution of 20% of the feed by thawed white fish (hake) slightly counteracted the negative effects of Hg. The effects were not statistically significant and were dependent, in a non-linear manner, on the Se/Hg molar ratio of the feed but not on its Hg concentration. These results stress the need to consider the Se/Hg molar ratio of the feed/ food when evaluating the toxicity of Hg.

Introduction. Glutathione peroxidases are selenoenzymes which have a crucial role in the protection of animals against oxidative stress. Materials and Methods. From September 2017 to April 2018, a group of eight red-eared sliders were admitted at the Clinic for Small Animals, Faculty of Veterinary Medicine, University of Belgrade for elective diagnostic celioscopy. The turtles were of unknown age, weight from 1.20 kg to 1.86 kg. The anesthesia protocol involved using ketamine and medetomidine, both at a low dosage (10 mg kg-1 and 0.1 mg kg-1, respectively) as induction, after which anesthesia was maintained using isoflurane at 3% (vapor setting) in 100% oxygen (0.5 L min-1). Medetomidine was reversed with atipamezole (0.2 mg kg-1), given intramuscularly. The elective celioscopy was performed according to standard protocols. One day prior to anesthesia, heparinized blood samples were taken using the subcarapacial venous plexus for venipuncture. The second sampling took place three hours after the anesthetics were administered. Results and Conclusions. GPx3 activity in the blood plasmas (n=8) was measured by the coupled test as described by Günzler et al. (1974). Data were tested for normality by the Shapiro-Wilk normality test and the groups were compared using a paired t-test. Blood plasma GPx3 activity was significantly higher (p=0.009) after a three-hour recovery period from inhalation anesthesia performed for elective diagnostic celioscopy, than before anesthesia. The measured post-anesthesia GPx3 activities were, on average, 80% higher than the measurements prior to anesthesia. It can be concluded that the statistically significant increase in the activity of plasma GPx3 from 91.02±36.05 mKat L-1 prior to anesthesia to 160.21±58.94 mKat L-1 three hours after anesthesia is due to the change in oxygen saturation. This is increased to 100% during the procedure, thus exposing the turtles to conditions of high oxygen saturation., Uvod. Glutation peroksidaze su selenoenzimi koji igraju ključnu ulogu u zaštiti životinja od oksidativnog stresa. Materijal i metode. Od septembra 2017. do aprila 2018. godine, grupa od osam crvenouhih kornjača je primljena na Kliniku za male životinje, Fakulteta Veterinarske Medicine, Univerziteta u Beogradu zbog izvođenja elektivne dijagnostičke celioskopije. Kornjače su bile nepoznate starosti, mase između 1,20 kg i 1,86 kg. Anastetički protokol je uključivao primenu ketamina (10 mg kg-1) i medetomidina (0.1 mg kg-1) za indukciju, oba u niskim dozama, nakon čega je anestezija održavana primenom izoflurana u koncentraciji od 3% (podešen na isparavanje) u 100% kiseoniku (0.5 L min-1). Dejstvo medetomidina je neutralizovano atipamezolom (0.2 mg kg-1), aplikovanim intramuskularno. Elektivna celioskopija je izvedena u skladu sa standardnim protokolima. Heparinizovani uzorci krvi su uzeti jedan dan pre uvođenja u anesteziju venepunkcijom iz subkarapacijalnog venskog pleksusa. Drugo uzorkovanje krvi je uzvršeno tri sata nakon administracije anestetika. Rezultati i zaključak. GPx3 aktivnost u krvnoj plazmi (n=8) je izmerena primenom kuplovane reakcije, kao što su opisali Günzler i sar. (1974). Normalna distribucija podataka je testirana pomoću Shapiro - Wilk testa normalnosti (p>0,05), a grupe su poređene koristeći t test za zavisne uzorke. Aktivnost GPx3 u krvnoj plazmi je bila značajno viša (p=0.009) u uzorcima uzetim nakon trosatnog perioda oporavka od inhalacione anestezije aplikovane radi izvođenja elektivne celioskopije, nego u uzorcima uzetim pre aplikovanja anestezije. Vrednosti GPx3 izmerene nakon anestezije bile su u proseku 80% više od vrednosti pre anestezije. Može se zaključiti da je statistički značajan porast u aktivnosti GPx3 u plazmi od 91.02±36.05 mKat L-1, pre anestezije do 160.21±58.94 mKat L-1, tri sata nakon anestezije uzrokovan promenom u saturaciji kiseonika. Tokom intervencije saturacija kiseonika se povećava i do 100% čime se kornjače uvode u us

Background:Barium selenate is an inorganic source of selenium (Se) used in prolonged-release preparations to treat selenium deficiency in bovines. Objective: To evaluate serum concentrations of triiodothyronine (T3) and thyroxine (T4) hormones in newborn calves from mothers supplemented with barium selenate during prepartum. Methods: Six black Frisian pregnant cows were supplemented with barium selenate subcutaneously during the last two months of gestation, until calving. Six cows were used as controls. All cows were subjected to a low Se diet, consisting of hay from natural pasture and commercial concentrate lacking Se. The Se balance was measured through the activity of erythrocyte glutathione peroxidase (GPx). Serum concentration of T3 and T4 in calves was determined by electrochemiluminescence. Results: Se supplementation during prepartum increased GPx activity in cows from day 45 post-supplementation (p<0.05). Calves from supplemented mothers showed higher average serum Se concentration than calves from non-supplemented mothers. The average concentration of T3 in the calves from supplemented mothers was lower in the first hour of life (p<0.05) compared with calves from mothers of the non-supplemented group. A decrease (p<0.05) in T4 serum concentrations was observed in both groups at seven days of age. Conclusions: Administration of barium selenate to cows during prepartum generates a reduction in serum concentration of T3 in the first hour of life of calves., Antecedentes: O selenato de bário é uma fonte inorgânica de selênio (Se) usada em preparações de liberação prolongada para corrigir o status de deficiência de Se em bovinos. Objetivo: Avaliar as concentrações séricas de triiodotironina (T3) e tiroxina (T4) em bezerros recém-nascidos de mães suplementadas durante o pré-parto com selenato de bário. Métodos: Seis vacas friesianas negras aos 7 meses de gestação foram suplementadas com selenato de bário por via subcutânea dois meses antes do parto. Seis outras vacas permaneceram como controle. Todas as vacas foram mantidas em uma dieta cuja contribuição de Se foi inferior aos requeridos e consistiram em feno natural da pradaria e concentrado comercial sem Se. O balanço de Se foi medido usando a atividade eritrocitária das concentrações de glutationa peroxidase (GPx) e T3 e T4 em bezerros por eletroquimiluminescência. Resultados: A suplementação com atividade de GPx aumentou em vacas a partir do dia 45 após a suplementação (p<0,05). Os bezerros de mães suplementadas apresentaram uma concentração sérica média de Se maior que os bezerros de mães não suplementadas. A concentração média de T3 dos bezerros das mães suplementadas foi menor na primeira hora de vida (p<0,05) do que nos bezerros das mães não suplementadas. Aos 7 dias de idade houve uma diminuição (p<0,05) nas concentrações séricas de T4 nos dois grupos. Conclusão: A administração de selenato de bário em vacas de parto gera uma diminuição na concentração sérica de T3 na primeira hora de vida do bezerro., Antecedentes: El selenato de bario es una fuente inorgánica de selenio (Se) utilizada en preparaciones de liberación prolongada para corregir el estado de carencia de Se en bovinos. Objetivo: Evaluar las concentraciones séricas de triyodotironina (T3) y tiroxina (T4) en terneros recién nacidos de madres suplementadas durante el preparto con selenato de bario. Métodos: Seis vacas frisón negro con 7 meses de gestación fueron suplementadas vía subcutánea con selenato de bario dos meses previos a la fecha de parto. Otras seis vacas permanecieron como controles. Todas las vacas se mantuvieron con una dieta cuyo aporte de Se fue inferior a los requerimientos y consistió en heno de pradera natural y concentrado comercial sin Se. El balance de Se se midió usando la actividad eritrocitaria de glutatión peroxidasa (GPx) y las concentraciones de T3y T4 en terneros mediante electroquimioluminiscencia. Resultados: La suplementación con Se aumentó la actividad de GPx en vacas desde el día 45 post suplementación (p<0,05). Los terneros de madres suplementadas mostraron una concentración sérica promedio de Se mayor que los terneros de madres no suplementadas. La concentración promedio de T3 de terneros de madres suplementadas fue menor en la primera hora de vida (p<0,05) que en terneros de madres no suplementadas. A los 7 días de edad hubo una disminución (p<0,05) en las concentraciones séricas de T4 en ambos grupos. Conclusión: La administración de selenato de bario en vacas preparto genera una disminución en la concentración sérica de T3 en la primera hora de vida del ternero.

This study aimed to evaluate, in vitro, the antioxidative potential of fruit wines produced from berry fruits (i.e., black chokeberry, blueberry, blackberry, and raspberry), cherry, and apple by different technological processes. For this purpose, the activities of antioxidant enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)) and malondialdehyde (MDA) content as a marker of membrane damage were determined in wine-treated synaptosomes with hydrogen peroxide-induced oxidative stress. All studied wines induced increased antioxidant enzyme activities and decreased MDA levels compared to hydrogen peroxide-treated synaptosomes (i.e., control). The highest SOD activity was observed in synaptosomes treated with blackberry wine (6.81 U/mg), whereas blueberry wine induced the highest catalase and glutathione peroxidase activities (0.058 U/mg and 0.017 U/mg, respectively). Black chokeberry proved to be the best in lipid peroxidation protection with the lowest MDA value (1.42 nmol/mg). Finally, principal component analysis and hierarchical cluster analysis additionally highlighted a higher antioxidant capacity of wines produced from dark-skinned fruits (i.e., blackberry, black chokeberry, and blueberry). The results suggest protective effects of the fruit wines against oxidative damage, and, accordingly, their promising application as functional food.

[EN] Feeding 3.9 and 6.7 mg Hg/kg (Se/Hg molar ratios of 0.8 and 0.4, respectively) for 14 days negatively affected Dicentrarchus labrax growth and total DNTB- and thioredoxin-reductase (TrxR) activities and the transcription of four redox genes (txn1, gpx1, txnrd3, and txnrd2) in the liver, but a diet with 0.5 mg Hg/kg (Se/Hg molar ratio 6.6) slightly increased both reductase activities and the transcription of txn1, gpx1, and txnrd2. Feeding 6.7 mg Hg/kg for 53 days downregulated the genes of the thioredoxin system (txn1, txnrd3, and txnrd2) but upregulated gpx1, confirming the previously proposed complementarity among the antioxidant systems. Substitution of 20% of the feed by thawed white fish (hake) slightly counteracted the negative effects of Hg. The effects were not statistically significant and were dependent, in a non-linear manner, on the Se/Hg molar ratio of the feed but not on its Hg concentration. These results stress the need to consider the Se/Hg molar ratio of the feed/ food when evaluating the toxicity of Hg.

The molecular basis for adaptations to extreme environments can now be understood by interrogating the ever-increasing number of sequenced genomes. Mammals such as cetaceans, bats, and highland species can protect themselves from oxidative stress, a disruption in the balance of reactive oxygen species, which results in oxidative injury and cell damage. Here, we consider the evolution of the glutathione peroxidase (GPX) family of antioxidant enzymes by interrogating publicly available genome data from 70 mammalian species from all major clades. We identified 8 GPX subclasses ubiquitous to all mammalian groups. Mammalian GPX gene families resolved into the GPX4/7/8 and GPX1/2/3/5/6 groups and are characterized by several instances of gene duplication and loss, indicating a dynamic process of gene birth and death in mammals. Seven of the eight GPX subfamilies (all but GPX7) were under positive selection, with the residues under selection located at or close to active sites or at the dimer interface. We also reveal evidence of a correlation between ecological niches (e.g. high oxidative stress) and the divergent selection and gene copy number of GPX subclasses. Notably, a convergent expansion of GPX1 was observed in several independent lineages of mammals under oxidative stress and may be important for avoiding oxidative damage. Collectively, this study suggests that the GPX gene family has shaped the adaption of mammals to stressful environments.

Background:Barium selenate is an inorganic source of selenium (Se) used in prolonged-release preparations to treat selenium deficiency in bovines. Objective: To evaluate serum concentrations of triiodothyronine (T3) and thyroxine (T4) hormones in newborn calves from mothers supplemented with barium selenate during prepartum. Methods: Six black Frisian pregnant cows were supplemented with barium selenate subcutaneously during the last two months of gestation, until calving. Six cows were used as controls. All cows were subjected to a low Se diet, consisting of hay from natural pasture and commercial concentrate lacking Se. The Se balance was measured through the activity of erythrocyte glutathione peroxidase (GPx). Serum concentration of T3 and T4 in calves was determined by electrochemiluminescence. Results: Se supplementation during prepartum increased GPx activity in cows from day 45 post-supplementation (p<0.05). Calves from supplemented mothers showed higher average serum Se concentration than calves from non-supplemented mothers. The average concentration of T3 in the calves from supplemented mothers was lower in the first hour of life (p<0.05) compared with calves from mothers of the non-supplemented group. A decrease (p<0.05) in T4 serum concentrations was observed in both groups at seven days of age. Conclusions: Administration of barium selenate to cows during prepartum generates a reduction in serum concentration of T3 in the first hour of life of calves., Antecedentes: O selenato de bário é uma fonte inorgânica de selênio (Se) usada em preparações de liberação prolongada para corrigir o status de deficiência de Se em bovinos. Objetivo: Avaliar as concentrações séricas de triiodotironina (T3) e tiroxina (T4) em bezerros recém-nascidos de mães suplementadas durante o pré-parto com selenato de bário. Métodos: Seis vacas friesianas negras aos 7 meses de gestação foram suplementadas com selenato de bário por via subcutânea dois meses antes do parto. Seis outras vacas permaneceram como controle. Todas as vacas foram mantidas em uma dieta cuja contribuição de Se foi inferior aos requeridos e consistiram em feno natural da pradaria e concentrado comercial sem Se. O balanço de Se foi medido usando a atividade eritrocitária das concentrações de glutationa peroxidase (GPx) e T3 e T4 em bezerros por eletroquimiluminescência. Resultados: A suplementação com atividade de GPx aumentou em vacas a partir do dia 45 após a suplementação (p<0,05). Os bezerros de mães suplementadas apresentaram uma concentração sérica média de Se maior que os bezerros de mães não suplementadas. A concentração média de T3 dos bezerros das mães suplementadas foi menor na primeira hora de vida (p<0,05) do que nos bezerros das mães não suplementadas. Aos 7 dias de idade houve uma diminuição (p<0,05) nas concentrações séricas de T4 nos dois grupos. Conclusão: A administração de selenato de bário em vacas de parto gera uma diminuição na concentração sérica de T3 na primeira hora de vida do bezerro., Antecedentes: El selenato de bario es una fuente inorgánica de selenio (Se) utilizada en preparaciones de liberación prolongada para corregir el estado de carencia de Se en bovinos. Objetivo: Evaluar las concentraciones séricas de triyodotironina (T3) y tiroxina (T4) en terneros recién nacidos de madres suplementadas durante el preparto con selenato de bario. Métodos: Seis vacas frisón negro con 7 meses de gestación fueron suplementadas vía subcutánea con selenato de bario dos meses previos a la fecha de parto. Otras seis vacas permanecieron como controles. Todas las vacas se mantuvieron con una dieta cuyo aporte de Se fue inferior a los requerimientos y consistió en heno de pradera natural y concentrado comercial sin Se. El balance de Se se midió usando la actividad eritrocitaria de glutatión peroxidasa (GPx) y las concentraciones de T3y T4 en terneros mediante electroquimioluminiscencia. Resultados: La suplementación con Se aumentó la actividad de GPx en vacas desde el día 45 post suplementación (p<0,05). Los terneros de madres suplementadas mostraron una concentración sérica promedio de Se mayor que los terneros de madres no suplementadas. La concentración promedio de T3 de terneros de madres suplementadas fue menor en la primera hora de vida (p<0,05) que en terneros de madres no suplementadas. A los 7 días de edad hubo una disminución (p<0,05) en las concentraciones séricas de T4 en ambos grupos. Conclusión: La administración de selenato de bario en vacas preparto genera una disminución en la concentración sérica de T3 en la primera hora de vida del ternero.

Introduction. Glutathione peroxidases are selenoenzymes which have a crucial role in the protection of animals against oxidative stress. Materials and Methods. From September 2017 to April 2018, a group of eight red-eared sliders were admitted at the Clinic for Small Animals, Faculty of Veterinary Medicine, University of Belgrade for elective diagnostic celioscopy. The turtles were of unknown age, weight from 1.20 kg to 1.86 kg. The anesthesia protocol involved using ketamine and medetomidine, both at a low dosage (10 mg kg-1 and 0.1 mg kg-1, respectively) as induction, after which anesthesia was maintained using isoflurane at 3% (vapor setting) in 100% oxygen (0.5 L min-1). Medetomidine was reversed with atipamezole (0.2 mg kg-1), given intramuscularly. The elective celioscopy was performed according to standard protocols. One day prior to anesthesia, heparinized blood samples were taken using the subcarapacial venous plexus for venipuncture. The second sampling took place three hours after the anesthetics were administered. Results and Conclusions. GPx3 activity in the blood plasmas (n=8) was measured by the coupled test as described by Günzler et al. (1974). Data were tested for normality by the Shapiro-Wilk normality test and the groups were compared using a paired t-test. Blood plasma GPx3 activity was significantly higher (p=0.009) after a three-hour recovery period from inhalation anesthesia performed for elective diagnostic celioscopy, than before anesthesia. The measured post-anesthesia GPx3 activities were, on average, 80% higher than the measurements prior to anesthesia. It can be concluded that the statistically significant increase in the activity of plasma GPx3 from 91.02±36.05 mKat L-1 prior to anesthesia to 160.21±58.94 mKat L-1 three hours after anesthesia is due to the change in oxygen saturation. This is increased to 100% during the procedure, thus exposing the turtles to conditions of high oxygen saturation., Uvod. Glutation peroksidaze su selenoenzimi koji igraju ključnu ulogu u zaštiti životinja od oksidativnog stresa. Materijal i metode. Od septembra 2017. do aprila 2018. godine, grupa od osam crvenouhih kornjača je primljena na Kliniku za male životinje, Fakulteta Veterinarske Medicine, Univerziteta u Beogradu zbog izvođenja elektivne dijagnostičke celioskopije. Kornjače su bile nepoznate starosti, mase između 1,20 kg i 1,86 kg. Anastetički protokol je uključivao primenu ketamina (10 mg kg-1) i medetomidina (0.1 mg kg-1) za indukciju, oba u niskim dozama, nakon čega je anestezija održavana primenom izoflurana u koncentraciji od 3% (podešen na isparavanje) u 100% kiseoniku (0.5 L min-1). Dejstvo medetomidina je neutralizovano atipamezolom (0.2 mg kg-1), aplikovanim intramuskularno. Elektivna celioskopija je izvedena u skladu sa standardnim protokolima. Heparinizovani uzorci krvi su uzeti jedan dan pre uvođenja u anesteziju venepunkcijom iz subkarapacijalnog venskog pleksusa. Drugo uzorkovanje krvi je uzvršeno tri sata nakon administracije anestetika. Rezultati i zaključak. GPx3 aktivnost u krvnoj plazmi (n=8) je izmerena primenom kuplovane reakcije, kao što su opisali Günzler i sar. (1974). Normalna distribucija podataka je testirana pomoću Shapiro - Wilk testa normalnosti (p>0,05), a grupe su poređene koristeći t test za zavisne uzorke. Aktivnost GPx3 u krvnoj plazmi je bila značajno viša (p=0.009) u uzorcima uzetim nakon trosatnog perioda oporavka od inhalacione anestezije aplikovane radi izvođenja elektivne celioskopije, nego u uzorcima uzetim pre aplikovanja anestezije. Vrednosti GPx3 izmerene nakon anestezije bile su u proseku 80% više od vrednosti pre anestezije. Može se zaključiti da je statistički značajan porast u aktivnosti GPx3 u plazmi od 91.02±36.05 mKat L-1, pre anestezije do 160.21±58.94 mKat L-1, tri sata nakon anestezije uzrokovan promenom u saturaciji kiseonika. Tokom intervencije saturacija kiseonika se povećava i do 100% čime se kornjače uvode u us

This study aimed to evaluate, in vitro, the antioxidative potential of fruit wines produced from berry fruits (i.e., black chokeberry, blueberry, blackberry, and raspberry), cherry, and apple by different technological processes. For this purpose, the activities of antioxidant enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)) and malondialdehyde (MDA) content as a marker of membrane damage were determined in wine-treated synaptosomes with hydrogen peroxide-induced oxidative stress. All studied wines induced increased antioxidant enzyme activities and decreased MDA levels compared to hydrogen peroxide-treated synaptosomes (i.e., control). The highest SOD activity was observed in synaptosomes treated with blackberry wine (6.81 U/mg), whereas blueberry wine induced the highest catalase and glutathione peroxidase activities (0.058 U/mg and 0.017 U/mg, respectively). Black chokeberry proved to be the best in lipid peroxidation protection with the lowest MDA value (1.42 nmol/mg). Finally, principal component analysis and hierarchical cluster analysis additionally highlighted a higher antioxidant capacity of wines produced from dark-skinned fruits (i.e., blackberry, black chokeberry, and blueberry). The results suggest protective effects of the fruit wines against oxidative damage, and, accordingly, their promising application as functional food.

To study the effect of resveratrol on the antioxidant system of Litopenaeus vannamei, resveratrol (0, 40, 80, 120 and 180 mg/kg) was added to the feed. After 7 days of culture, 10 tails of L. vannamei were randomly selected and exposure to ammonia stress at the sublethal concentration of ammonia (20 mg/L) for 24h. The results showed that the malondialdehyde (MDA) level in serum of shrimp fed with resveratrol decreased significantly compare to the control group (p< 0.05). After the ammonia stress, the MDA levels in serum in the Res 120 group and the Res 160 group was lower significantly than that in the control group (p< 0.05). The activities of superoxide dismutase (SOD) in the hepatopancreas and the serum, and glutathione peroxidase (GPX) in the serum of shrimps fed with resveratrol showed a decrease trend before the ammonia stress. Conversely, the activities of SOD and the total antioxidant competence (T-AOC) levels in the hepatopancreas in the Res 80 group and Res 120 group were significantly higher than that in the control group after the ammonia stress (p<0.05). Dietary resveratrol decreased oxidative damage, increased antioxidant enzyme activities under the ammonia stress. Our results demonstrated that resveratrol attenuated oxidative stress and improved the resistance to the ammonia stress.

This study aimed to evaluate, in vitro, the antioxidative potential of fruit wines produced from berry fruits (i.e., black chokeberry, blueberry, blackberry, and raspberry), cherry, and apple by different technological processes. For this purpose, the activities of antioxidant enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)) and malondialdehyde (MDA) content as a marker of membrane damage were determined in wine-treated synaptosomes with hydrogen peroxide-induced oxidative stress. All studied wines induced increased antioxidant enzyme activities and decreased MDA levels compared to hydrogen peroxide-treated synaptosomes (i.e., control). The highest SOD activity was observed in synaptosomes treated with blackberry wine (6.81 U/mg), whereas blueberry wine induced the highest catalase and glutathione peroxidase activities (0.058 U/mg and 0.017 U/mg, respectively). Black chokeberry proved to be the best in lipid peroxidation protection with the lowest MDA value (1.42 nmol/mg). Finally, principal component analysis and hierarchical cluster analysis additionally highlighted a higher antioxidant capacity of wines produced from dark-skinned fruits (i.e., blackberry, black chokeberry, and blueberry). The results suggest protective effects of the fruit wines against oxidative damage, and, accordingly, their promising application as functional food.

[EN] Feeding 3.9 and 6.7 mg Hg/kg (Se/Hg molar ratios of 0.8 and 0.4, respectively) for 14 days negatively affected Dicentrarchus labrax growth and total DNTB- and thioredoxin-reductase (TrxR) activities and the transcription of four redox genes (txn1, gpx1, txnrd3, and txnrd2) in the liver, but a diet with 0.5 mg Hg/kg (Se/Hg molar ratio 6.6) slightly increased both reductase activities and the transcription of txn1, gpx1, and txnrd2. Feeding 6.7 mg Hg/kg for 53 days downregulated the genes of the thioredoxin system (txn1, txnrd3, and txnrd2) but upregulated gpx1, confirming the previously proposed complementarity among the antioxidant systems. Substitution of 20% of the feed by thawed white fish (hake) slightly counteracted the negative effects of Hg. The effects were not statistically significant and were dependent, in a non-linear manner, on the Se/Hg molar ratio of the feed but not on its Hg concentration. These results stress the need to consider the Se/Hg molar ratio of the feed/ food when evaluating the toxicity of Hg.

Feeding 3.9 and 6.7 mg Hg/kg (Se/Hg molar ratios of 0.8 and 0.4, respectively) for 14 days negatively affected Dicentrarchus labrax growth and total DNTB- and thioredoxin-reductase (TrxR) activities and the transcription of four redox genes (txn1, gpx1, txnrd3, and txnrd2) in the liver, but a diet with 0.5 mg Hg/kg (Se/Hg molar ratio 6.6) slightly increased both reductase activities and the transcription of txn1, gpx1, and txnrd2. Feeding 6.7 mg Hg/kg for 53 days downregulated the genes of the thioredoxin system (txn1, txnrd3, and txnrd2) but upregulated gpx1, confirming the previously proposed complementarity among the antioxidant systems. Substitution of 20% of the feed by thawed white fish (hake) slightly counteracted the negative effects of Hg. The effects were not statistically significant and were dependent, in a non-linear manner, on the Se/Hg molar ratio of the feed but not on its Hg concentration. These results stress the need to consider the Se/Hg molar ratio of the feed/food when evaluating the toxicity of Hg.

This study aimed to evaluate, in vitro, the antioxidative potential of fruit wines produced from berry fruits (i.e., black chokeberry, blueberry, blackberry, and raspberry), cherry, and apple by different technological processes. For this purpose, the activities of antioxidant enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)) and malondialdehyde (MDA) content as a marker of membrane damage were determined in wine-treated synaptosomes with hydrogen peroxide-induced oxidative stress. All studied wines induced increased antioxidant enzyme activities and decreased MDA levels compared to hydrogen peroxide-treated synaptosomes (i.e., control). The highest SOD activity was observed in synaptosomes treated with blackberry wine (6.81 U/mg), whereas blueberry wine induced the highest catalase and glutathione peroxidase activities (0.058 U/mg and 0.017 U/mg, respectively). Black chokeberry proved to be the best in lipid peroxidation protection with the lowest MDA value (1.42 nmol/mg). Finally, principal component analysis and hierarchical cluster analysis additionally highlighted a higher antioxidant capacity of wines produced from dark-skinned fruits (i.e., blackberry, black chokeberry, and blueberry). The results suggest protective effects of the fruit wines against oxidative damage, and, accordingly, their promising application as functional food.

Atherosclerosis is a chronic inflammatory disease of the vasculature characterised by the infiltration of activated neutrophils and macrophages at sites of damage within the vessel wall, which contributes to lesion formation and plaque progression. Selenomethionine (SeMet) is an organic form of selenium (Se), an essential trace element that functions in the regulation of the immune response by both bolstering the endogenous thioredoxin and glutathione antioxidant defence systems and by directly scavenging damaging oxidant species. This study evaluated the effect of dietary SeMet supplementation within a high fat diet fed apolipoprotein E deficient (ApoE(-/-)) mouse model of atherosclerosis. Dietary supplementation with SeMet (2 mg/kg) increased the tissue concentration of Se, and the expression and activity of glutathione peroxidase, compared to non-supplemented controls. Supplementation with SeMet significantly reduced atherosclerotic plaque formation in mouse aortae, resulted in a more stable lesion phenotype and improved vessel function. Concurrent with these results, SeMet supplementation decreased lesion accumulation of M1 inflammatory type macrophages, and decreased the extent of extracellular trap release from phorbol myristate acetate (PMA)-stimulated mouse bone marrow-derived cells. Importantly, these latter results were replicated within ex-vivo experiments on cultured neutrophils isolated from acute coronary syndrome patients, indicating the ability of SeMet to alter the acute inflammatory response within a clinically-relevant setting. Together, these data highlight the potential beneficial effect of SeMet supplementation as a therapeutic strategy for atherosclerosis.

Selenium is a trace element, nutritionally classified as an essential micronutrient, involved in maintaining the correct function of several enzymes incorporating the selenocysteine residue, namely the selenoproteins. The human selenoproteome including 25 proteins is extensively described here. The most relevant selenoproteins, including glutathione peroxidases, thioredoxin reductases and iodothyronine deiodinases are required for the proper cellular redox homeostasis as well as for the correct thyroid function, thus preventing oxidative stress and related diseases. This review summarizes the main advances on oxidative stress with a focus on selenium metabolism and transport. Moreover, thyroid-related disorders are discussed, considering that the thyroid gland contains the highest selenium amount per gram of tissue, also for future possible therapeutic implication.

Atherosclerosis is a chronic inflammatory disease of the vasculature characterised by the infiltration of activated neutrophils and macrophages at sites of damage within the vessel wall, which contributes to lesion formation and plaque progression. Selenomethionine (SeMet) is an organic form of selenium (Se), an essential trace element that functions in the regulation of the immune response by both bolstering the endogenous thioredoxin and glutathione antioxidant defence systems and by directly scavenging damaging oxidant species. This study evaluated the effect of dietary SeMet supplementation within a high fat diet fed apolipoprotein E deficient (ApoE(-/-)) mouse model of atherosclerosis. Dietary supplementation with SeMet (2 mg/kg) increased the tissue concentration of Se, and the expression and activity of glutathione peroxidase, compared to non-supplemented controls. Supplementation with SeMet significantly reduced atherosclerotic plaque formation in mouse aortae, resulted in a more stable lesion phenotype and improved vessel function. Concurrent with these results, SeMet supplementation decreased lesion accumulation of M1 inflammatory type macrophages, and decreased the extent of extracellular trap release from phorbol myristate acetate (PMA)-stimulated mouse bone marrow-derived cells. Importantly, these latter results were replicated within ex-vivo experiments on cultured neutrophils isolated from acute coronary syndrome patients, indicating the ability of SeMet to alter the acute inflammatory response within a clinically-relevant setting. Together, these data highlight the potential beneficial effect of SeMet supplementation as a therapeutic strategy for atherosclerosis.

Cancer is considered one of the most serious diseases that threaten the society at present. Accordingly, some antioxidants have been studied about breast cancer during chemotherapy and the effect of this treatment on antioxidants that protect cells from oxidation and damage associated with cancer. This study was conducted on (92) Participants; (52) of which for patients with breast cancer who are aged between (25-80) year. Additionally, (40) healthy people aged between (22-75) year were enrolled. The samples were obtained from the Center for Oncology in Azadi Teaching Hospital in Kirkuk. This research deals with the study of glutathione peroxidase (GPx) using gel filtration (Sephadex-50) and the dimension column (28×1.5) cm. The serum from a patient with breast cancer was partially purified and compared with that from healthy female control. The effect of chemotherapy on GPx, Catalase (CAT), Glutathione (GSH) and Uric acid (U. A) has studied as an antioxidant. The results showed, A substantial decrease in the catalase enzyme in the different groups of chemical doses (A, B, C and D) Group (A) consists of patients undergoing chemotherapy from (1-3) Chemotherapy doses. Group (B) consists from (4-6) Chemotherapy doses, Group (C) consists from (7-9) Chemotherapy doses, Group (D) consists from (10-12) Chemotherapy doses at a Statistical level (p ?0.01). On the other hand, the group (E) consists from (13-16) Chemotherapy doses has found no considerable difference, the drugs that make up the chemotherapy given to patients (Adriamycin, Cytoxan, methotrexate, Fluorouracil). the level of enzyme activity (GPx) at a Statistical level (p ?0.01). (C, D and E) groups is decrease, either groups represented by (A and B) with no significant difference was recorded, the level of enzyme activity (GSH) at a Statistical level (p ?0.01). (A) group is decrease, either groups represented by (B,C,D,E) groups with no significant difference was recorded,.Lastly, in the Uric acid, there ar

The aim of this study was to determine the effects of dietary grape seed polyphenols (GSP) supplementation during the late gestation and lactation period on reproductive performance, antioxidative status in serum, nutrient composition, and Ig content in colostrum of multiparous sows. On day 80 of gestation, a total of 64 sows with similar body condition were allocated to a completely randomized block design with 4 dietary treatments (n = 16 sows per treatment): 1) basal diet (CON, control group); 2) basal diet supplemented with 200 IU/kg vitamin E (200VE, positive control group); 3) basal diet supplemented with 200 mg/kg GSP (200GSP); and 4) basal diet supplemented with 300 mg/kg GSP (300GSP). The trial lasted 56 d until the piglets were weaned on day 21 of lactation. Reproductive performance, parameters of antioxidative status, and levels of progesterone (P4) and estradiol (E2) in serum, nutrient composition, and Ig content in colostrum of sows were determined. The number of dead fetuses was reduced, and farrowing survival was significantly improved in the litters from 300GSP-fed (P < 0.05). Preweaning survivability significantly increased in the litters from sows fed 200GSP and 200VE (P < 0.05). The activity of superoxide dismutase and glutathione peroxidase (GSH-Px) in the serum was significantly increased in sows fed 200GSP and 300GSP (P < 0.05). The activity of GSH-Px in the serum also significantly increased in sows fed 200VE (P < 0.05). Sows fed 300GSP had the greatest levels of P4 and E2 in the serum, which was significantly greater than sows fed 200VE and CON (P < 0.05). No significant differences were found among treatments for the content of solids-not-fat, fat, protein, and lactose in colostrum (P > 0.05). However, sows fed GSP had greater IgM and IgG content in colostrum compared with sows fed 200VE and CON (P < 0.05). In conclusion, dietary GSP supplementation during late gestation and lactation improved the farrowing survival and

Telomere attrition is a hallmark of cellular aging and shorter telomeres have been reported in mood and anxiety disorders. Telomere shortening is counteracted by the enzyme telomerase and cellular protection is also provided by the antioxidant enzyme glutathione peroxidase (GPx). Here, telomerase, GPx, and telomeres were investigated in 46 social anxiety disorder (SAD) patients in a within-subject design with repeated measures before and after cognitive behavioral therapy. Treatment outcome was assessed by the Liebowitz Social Anxiety Scale (self-report), administered three times before treatment to control for time and regression artifacts, and posttreatment. Venipunctures were performed twice before treatment, separated by 9 weeks, and once posttreatment. Telomerase activity and telomere length were measured in peripheral blood mononuclear cells and GPx activity in plasma. All patients contributed with complete data. Results showed that social anxiety symptom severity was significantly reduced from pretreatment to posttreatment (Cohen's d = 1.46). There were no significant alterations in telomeres or cellular protection markers before treatment onset. Telomere length and telomerase activity did not change significantly after treatment, but an increase in telomerase over treatment was associated with reduced social anxiety. Also, lower pretreatment telomerase activity predicted subsequent symptom improvement. GPx activity increased significantly during treatment, and increases were significantly associated with symptom improvement. The relationships between symptom improvement and putative protective enzymes remained significant also after controlling for body mass index, sex, duration of SAD, smoking, concurrent psychotropic medication, and the proportion of lymphocytes to monocytes. Thus, indices of cellular protection may be involved in the therapeutic mechanisms of psychological treatment for anxiety.

Cancer is considered one of the most serious diseases that threaten the society at present. Accordingly, some antioxidants have been studied about breast cancer during chemotherapy and the effect of this treatment on antioxidants that protect cells from oxidation and damage associated with cancer. This study was conducted on (92) Participants; (52) of which for patients with breast cancer who are aged between (25-80) year. Additionally, (40) healthy people aged between (22-75) year were enrolled. The samples were obtained from the Center for Oncology in Azadi Teaching Hospital in Kirkuk. This research deals with the study of glutathione peroxidase (GPx) using gel filtration (Sephadex-50) and the dimension column (28×1.5) cm. The serum from a patient with breast cancer was partially purified and compared with that from healthy female control. The effect of chemotherapy on GPx, Catalase (CAT), Glutathione (GSH) and Uric acid (U. A) has studied as an antioxidant. The results showed, A substantial decrease in the catalase enzyme in the different groups of chemical doses (A, B, C and D) Group (A) consists of patients undergoing chemotherapy from (1-3) Chemotherapy doses. Group (B) consists from (4-6) Chemotherapy doses, Group (C) consists from (7-9) Chemotherapy doses, Group (D) consists from (10-12) Chemotherapy doses at a Statistical level (p ?0.01). On the other hand, the group (E) consists from (13-16) Chemotherapy doses has found no considerable difference, the drugs that make up the chemotherapy given to patients (Adriamycin, Cytoxan, methotrexate, Fluorouracil). the level of enzyme activity (GPx) at a Statistical level (p ?0.01). (C, D and E) groups is decrease, either groups represented by (A and B) with no significant difference was recorded, the level of enzyme activity (GSH) at a Statistical level (p ?0.01). (A) group is decrease, either groups represented by (B,C,D,E) groups with no significant difference was recorded,.Lastly, in the Uric acid, there ar

Cancer is considered one of the most serious diseases that threaten the society at present. Accordingly, some antioxidants have been studied about breast cancer during chemotherapy and the effect of this treatment on antioxidants that protect cells from oxidation and damage associated with cancer. This study was conducted on (92) Participants; (52) of which for patients with breast cancer who are aged between (25-80) year. Additionally, (40) healthy people aged between (22-75) year were enrolled. The samples were obtained from the Center for Oncology in Azadi Teaching Hospital in Kirkuk. This research deals with the study of glutathione peroxidase (GPx) using gel filtration (Sephadex-50) and the dimension column (28×1.5) cm. The serum from a patient with breast cancer was partially purified and compared with that from healthy female control. The effect of chemotherapy on GPx, Catalase (CAT), Glutathione (GSH) and Uric acid (U. A) has studied as an antioxidant. The results showed, A substantial decrease in the catalase enzyme in the different groups of chemical doses (A, B, C and D) Group (A) consists of patients undergoing chemotherapy from (1-3) Chemotherapy doses. Group (B) consists from (4-6) Chemotherapy doses, Group (C) consists from (7-9) Chemotherapy doses, Group (D) consists from (10-12) Chemotherapy doses at a Statistical level (p ?0.01). On the other hand, the group (E) consists from (13-16) Chemotherapy doses has found no considerable difference, the drugs that make up the chemotherapy given to patients (Adriamycin, Cytoxan, methotrexate, Fluorouracil). the level of enzyme activity (GPx) at a Statistical level (p ?0.01). (C, D and E) groups is decrease, either groups represented by (A and B) with no significant difference was recorded, the level of enzyme activity (GSH) at a Statistical level (p ?0.01). (A) group is decrease, either groups represented by (B,C,D,E) groups with no significant difference was recorded,.Lastly, in the Uric acid, there ar

In the United States of America and in Mexico, zinc deficiency is a common nutritional disorder in pecan trees [Carya illinoinensis (Wangenh.) C. Koch], especially in calcareous soils. This study in Chihuahua, northern Mexico, analyses the effects of zinc nutritional status on various physiological and nutritional indicators, on the metabolism of oxidative stress, and on the yield and fruit quality of pecan. The aim was to identify possible bioindicators of soil zinc deficiency. The experimental design was completely randomized with four nutritional conditions with respect to zinc: a control and three levels of zinc deficiency - slight, moderate and severe. Zinc deficiency is characterised by small leaves with interveinal necrosis and rippled leaf margins. The lowest values of leaf area, SPAD values, total N and NO3 concentration were observed under conditions of severe zinc deficiency. With worsening zinc deficiency, results indicate an increased enzymatic activity of superoxide dismutase, catalase and glutathione peroxidase. Interestingly, under severe zinc deficiency there are decreases in trunk cross-sectional area growth, in yield and in percentage kernel. Increased activity of superoxide dismutase, catalase and peroxidase enzymes is associated with detoxification of reactive oxygen species. The activity of enzymes detoxifying reactive oxygen species lessens the negative effects of zinc deficiency stress, and may be good bioindicators of zinc deficiency and its visual symptoms on pecan trees.

Docosahexaenoic acid (DHA) is an omega‑3 polyunsaturated fatty acid, derived mainly from fish oil. It is well known that DHA is present in high concentrations in nervous tissue and plays an important role in brain development and neuroprotection. However, the molecular mechanisms underlying its role remain to be fully elucidated. In this study, to enhance our understanding of the pathophysiological role of DHA, we investigated the possible neuroprotective mechanisms of action of DHA against hydrogen peroxide (H2O2)‑induced oxidative damage in a rat pheochromocytoma cell line (PC12). Specifically, we evaluated the viability, oxidation potential, and the expression and production of antioxidant/cytoprotective enzymes, and eventual apoptosis. We found that pre‑treatment with DHA (24 h) protected the cells from H2O2‑induced oxidative damage. In particular, pre‑treatment with DHA: i) Antagonized the consistent decrease in viability observed following exposure to H2O2 for 24 h; ii) reduced the high levels of intracellular reactive oxygen species (ROS) associated with H2O2‑induced oxidative stress; iii) increased the intracellular levels of enzymatic antioxidants [superoxide dismutase (SOD) and glutathione peroxidase (GSH‑Px)] both under basal conditions and following H2O2 exposure; iv) augmented the intracellular levels of reduced glutathione (GSH) and ascorbic acid, while it reduced the malondialdehyde (MDA) levels under conditions of oxidative stress; v) upregulated the expression of nuclear factor (erythroid‑derived 2)‑like 2 (NFE2L2) and its downstream target protein, heme‑oxygenase‑1 (HO‑1); and vi) induced an anti‑apoptotic effect by decreasing Bax and increasing Bcl2 expression. These findings provide evidence suggesting that DHA is able to prevent H2O2‑induced oxidative damage to PC12 cells, which is attributed to its antioxidant and anti‑apoptotic effects via the regulation NFE2L2/HO‑1 signaling. Therefore, DHA may play protective role in neurodegenerative diseas

Telomere attrition is a hallmark of cellular aging and shorter telomeres have been reported in mood and anxiety disorders. Telomere shortening is counteracted by the enzyme telomerase and cellular protection is also provided by the antioxidant enzyme glutathione peroxidase (GPx). Here, telomerase, GPx, and telomeres were investigated in 46 social anxiety disorder (SAD) patients in a within-subject design with repeated measures before and after cognitive behavioral therapy. Treatment outcome was assessed by the Liebowitz Social Anxiety Scale (self-report), administered three times before treatment to control for time and regression artifacts, and posttreatment. Venipunctures were performed twice before treatment, separated by 9 weeks, and once posttreatment. Telomerase activity and telomere length were measured in peripheral blood mononuclear cells and GPx activity in plasma. All patients contributed with complete data. Results showed that social anxiety symptom severity was significantly reduced from pretreatment to posttreatment (Cohen's d = 1.46). There were no significant alterations in telomeres or cellular protection markers before treatment onset. Telomere length and telomerase activity did not change significantly after treatment, but an increase in telomerase over treatment was associated with reduced social anxiety. Also, lower pretreatment telomerase activity predicted subsequent symptom improvement. GPx activity increased significantly during treatment, and increases were significantly associated with symptom improvement. The relationships between symptom improvement and putative protective enzymes remained significant also after controlling for body mass index, sex, duration of SAD, smoking, concurrent psychotropic medication, and the proportion of lymphocytes to monocytes. Thus, indices of cellular protection may be involved in the therapeutic mechanisms of psychological treatment for anxiety.

The present study was conducted to assess effects of selenium (Se)-yeast supplementation on glutathione peroxidase activity, Se levels in tissues, growth performance, carcass, and meat composition in broilers. A total of 275 one-d-old Cobb 500 broilers of both sexes were randomly allotted to 1 of 5 treatments during a 42-d period. The 5 treatments differed only in Se content: group 1 had no additional Se (background only); groups 2, 3, and 4 received 0.3 mg/kg of added Se from the beginning of the trial until d 21, whereas in the second half of the study (from d 22 to 42), these groups received 0.3, 0.6, and 0.9 mg/kg of added Se, respectively; and group 5 received 0.9 mg/kg of Se for the entire experimental period. At the end of the study, the control group showed significantly lower (P < 0.01) glutathione peroxidase activity in blood plasma compared to Se-supplemented groups. Regarding Se concentration in various tissues, the groups receiving Se yeast showed higher plasma, feces, and meat Se contents than the control group (P < 0.01). Supplementation of Se improved broilers body weight, weight gain and feed conversion ratio (P < 0.01). Dressing percentage was lower in the control group and the group with 0.3 mg/kg of added Se compared to other experimental groups (0.6 and 0.9 mg/kg of dietary Se). The proportion of less valuable carcass parts (wings and legs) was higher (P < 0.01) in the group fed the basal diet compared to groups supplemented with 0.9 mg/kg of Se. Initial and ultimate pH values differed among experimental groups (P < 0.05). Supplementation of Se improved the broilers antioxidative resistance, growth performance, carcass quality, and chemical composition of meat.

Selenoproteins containing the 21st amino acid selenocysteine (Sec) exist in all three kingdoms of life and play essential roles in human health and development. The distinct low p Ka, high reactivity, and redox property of Sec also afford unique routes to protein modification and engineering. However, natural Sec incorporation requires idiosyncratic translational machineries that are dedicated to Sec and species-dependent, which makes it challenging to recombinantly prepare selenoproteins with high Sec specificity. As a consequence, the function of half of human selenoproteins remains unclear, and Sec-based protein manipulation has been greatly hampered. Here we report a new general method enabling the site-specific incorporation of Sec into proteins in E. coli. An orthogonal tRNAPyl-ASecRS was evolved to specifically incorporate Se-allyl selenocysteine (ASec) in response to the amber codon, and the incorporated ASec was converted to Sec in high efficiency through palladium-mediated cleavage under mild conditions compatible with proteins and cells. This approach completely obviates the natural Sec-dedicated factors, thus allowing various selenoproteins, regardless of Sec position and species source, to be prepared with high Sec specificity and enzyme activity, as shown by the preparation of human thioredoxin and glutathione peroxidase 1. Sec-selective labeling in the presence of Cys was also demonstrated on the surface of live E. coli cells. The tRNAPyl-ASecRS pair was further used in mammalian cells to incorporate ASec, which was converted into Sec by palladium catalyst in cellulo. This robust and versatile method should greatly facilitate the study of diverse natural selenoproteins and the engineering of proteins in general via site-specific introduction of Sec.

Background: Generally speaking, erythrocyte haemoglobin (Hb) is pro-oxidant in nature constantly generating superoxide (O2-) species in biological system of all Hb phenotypes. Sometimes, this reactive oxygen species (ROS) triggers lipid peroxidation with eventual rise in oxidative stress, particularly when the supposed self-sustaining antioxidant defence system is overwhelmed. Worse still, abnormal Hb generates multiple of O2- specie. Recent evidence has linked abnormal haemoglobins S and C in sickle cell diseases (SCD) to various complications with multiple pro-oxidant processes; however, similar studies in relation with abnormal haemoglobin traits are sparse. More so, reports on rate of activities of various antioxidant enzymes in SCDs are still contradictory. This study aimed to assess interplay between lipid peroxidation and antioxidant defence capacity in various haemoglobin variants. Method : A total number of 150 participants with different haemoglobin variants were recruited. Plasma levels of malondialdehyde (MDA), total antioxidant status (TAS), superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes were assayed using spectrophotometric method. Result: The results showed that plasma levels of MDA and erythrocytic SOD were significantly increased (P 0.05) in abnormal haemoglobins in that order of HbSS >HbSC >HbAC >HbAS, when compared with controls (HbAA). Conversely, plasma levels of GPx and TAS showed significant reductions (p 0.05), respectively. Conclusion: The results suggest that both sickle cell diseases and the carriers were relatively more vulnerable to systemic oxidative stress (in that order of HbSS> HbSC > HbAC >HbAS) contrary to normal haemoglobin phenotype, possibly owing to ineffective antioxidant mechanisms needed for keeping spontaneous generation of free radicals in control.

Background: Generally speaking, erythrocyte haemoglobin (Hb) is pro-oxidant in nature constantly generating superoxide (O2-) species in biological system of all Hb phenotypes. Sometimes, this reactive oxygen species (ROS) triggers lipid peroxidation with eventual rise in oxidative stress, particularly when the supposed self-sustaining antioxidant defence system is overwhelmed. Worse still, abnormal Hb generates multiple of O2- specie. Recent evidence has linked abnormal haemoglobins S and C in sickle cell diseases (SCD) to various complications with multiple pro-oxidant processes; however, similar studies in relation with abnormal haemoglobin traits are sparse. More so, reports on rate of activities of various antioxidant enzymes in SCDs are still contradictory. This study aimed to assess interplay between lipid peroxidation and antioxidant defence capacity in various haemoglobin variants. Method : A total number of 150 participants with different haemoglobin variants were recruited. Plasma levels of malondialdehyde (MDA), total antioxidant status (TAS), superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes were assayed using spectrophotometric method. Result: The results showed that plasma levels of MDA and erythrocytic SOD were significantly increased (P 0.05) in abnormal haemoglobins in that order of HbSS >HbSC >HbAC >HbAS, when compared with controls (HbAA). Conversely, plasma levels of GPx and TAS showed significant reductions (p 0.05), respectively. Conclusion: The results suggest that both sickle cell diseases and the carriers were relatively more vulnerable to systemic oxidative stress (in that order of HbSS> HbSC > HbAC >HbAS) contrary to normal haemoglobin phenotype, possibly owing to ineffective antioxidant mechanisms needed for keeping spontaneous generation of free radicals in control.

Major depressive disorder (MDD) has been linked to mitochondrial defects, which could manifest in mitochondrial DNA (mtDNA) polymorphisms or mutations. Additionally, copy number of mtDNA (mtDNA-cn) can be quantified in peripheral blood mononuclear cells (PBMC)s, indirectly reflecting cellular energetics, or in the circulating cell-free mtDNA (ccf-mtDNA) levels, which may reflect a fraction of the mitochondrial genome released during cellular stress. Few studies have examined ccf-mtDNA in MDD, and no studies have tested its relationship with intracellular mtDNA-cn or with antidepressant treatment response. Here, mtDNA levels were quantified in parallel from: (i) PBMCs and (ii) cell-free plasma of 50 unmedicated MDD subjects and 55 controls, in parallel with PBMC telomere length (TL) and antioxidant enzyme glutathione peroxidase (GpX) activity. MtDNA measures were repeated in 19 MDD subjects after 8 weeks of open-label SSRI treatment. In analyses adjusted for age, sex, BMI, and smoking, MDD subjects had significantly elevated levels of ccf-mtDNA (F = 20.6, p = 0.00002). PBMC mtDNA-cn did not differ between groups (p > 0.4). In preliminary analyses, we found that changes in ccf-mtDNA with SSRI treatment differed between SSRI responders and non-responders (F = 6.47, p = 0.02), with the non-responders showing an increase in ccf-mtDNA and responders not changing. Baseline ccf-mtDNA was positively correlated with GpX (r = 0.32, p = 0.001), and PBMC mtDNA correlated positively with PBMC TL (r = 0.38, p = 0.0001). These data suggest that plasma ccf-mtDNA and PBMC mtDNA-cn reflect different cellular processes and that the former may be more reflective of certain aspects of MDD pathophysiology and of the response to SSRI antidepressants.

BackgroundOxidative stress is responsible for some alterations in the chemical structure and, consequently, in the function of proteins, lipids, and DNA. Recent studies have linked oxidative stress to cancers, particularly thyroid cancer, but the mechanisms remain unclear. Here, we further characterize the role of oxidative stress in thyroid cancer by analyzing the expression of two selenium antioxidant molecules, glutathione peroxidase (GPx1) and thioredoxin reductase (TrxR1) in thyroid cancer cells.MethodsSamples of both healthy thyroid tissue and thyroid tumor were taken for analysis after total thyroidectomy. The expression of GPx1 and TrxR1 was revealed by Western blot analysis and quantified by densitometric analyses, while the evaluation of free radicals was performed by Electron Paramagnetic Resonance (EPR)-spin trapping technique.ResultsOur results show a decrease in the expression of GPx1 and TrxR1 (- 45.7 and - 43.2% respectively, p < 0.01) in the thyroid cancer cells compared to the healthy cells. In addition, the EPR technique shows an increase of free radicals in tumor tissue, significantly higher than that found in healthy thyroid tissue (+ 116.3%, p < 0.01).ConclusionsOur findings underscore the relationship between thyroid cancer and oxidative stress, showing the imbalance of the oxidant/antioxidant system in thyroid cancer tissue. These results suggest that either the inability to produce adequate antioxidant defense or an increased consumption of antioxidants, due to the hyper-production of free radicals, may play a crucial role in thyroid cancer.

Today, a few differing sources of selenium (Se), i.e. inorganic, organic, and nano forms of Se, are used as feed supplements for poultry. Published research indicates that nano-Se and organic Se possess comparable efficiency to inorganic Se in increasing GSH-Px activity of plasma and various tissues, but they deposit at higher rates in various tissues. However, there are principal differences in absorption mechanisms, metabolism, and efficiency of these three forms of Se. The aim of this review was to analyze the available literature on the effects of different Se sources and levels in the diet on glutathione peroxidase (GSH-Px) activity, tissue Se distribution and growth performance in poultry. Higher levels of Se increase GSH-Px activity in the body, but this reaches a plateau even if Se concentrations in diet increase further, while the deposition of Se in tissues increases as Se content in diet increases. In addition, many studies have shown the positive effects of adding Se to diet on growth performance in poultry. Optimal Se supplementation is necessary not only for good poultry health but also to ensure and preserve meat quality during storage and to provide human beings with this microelement.

The present study was conducted to assess effects of selenium (Se)-yeast supplementation on glutathione peroxidase activity, Se levels in tissues, growth performance, carcass, and meat composition in broilers. A total of 275 one-d-old Cobb 500 broilers of both sexes were randomly allotted to 1 of 5 treatments during a 42-d period. The 5 treatments differed only in Se content: group 1 had no additional Se (background only); groups 2, 3, and 4 received 0.3 mg/kg of added Se from the beginning of the trial until d 21, whereas in the second half of the study (from d 22 to 42), these groups received 0.3, 0.6, and 0.9 mg/kg of added Se, respectively; and group 5 received 0.9 mg/kg of Se for the entire experimental period. At the end of the study, the control group showed significantly lower (P < 0.01) glutathione peroxidase activity in blood plasma compared to Se-supplemented groups. Regarding Se concentration in various tissues, the groups receiving Se yeast showed higher plasma, feces, and meat Se contents than the control group (P < 0.01). Supplementation of Se improved broilers body weight, weight gain and feed conversion ratio (P < 0.01). Dressing percentage was lower in the control group and the group with 0.3 mg/kg of added Se compared to other experimental groups (0.6 and 0.9 mg/kg of dietary Se). The proportion of less valuable carcass parts (wings and legs) was higher (P < 0.01) in the group fed the basal diet compared to groups supplemented with 0.9 mg/kg of Se. Initial and ultimate pH values differed among experimental groups (P < 0.05). Supplementation of Se improved the broilers antioxidative resistance, growth performance, carcass quality, and chemical composition of meat.

The effects of chronic restraint stress (CRS, 2 h during 14 days) on gene expression of tyrosine hydroxylase (TH), catechol-O-methyltransferase (COMT), and glutathione peroxidase (GPx) were studied in the rat hippocampus. Changes in the dopamine (DA) concentration and activities of monoamine oxidases (MAO A and MAO B) and GPx in this cerebral structure of chronically stressed rats were also examined. The investigated parameters were quantified using real-time RT-PCR, Western blot analyses, and assay of enzymatic activity. We found that CRS decreased the TH protein level and DA concentration, which probably confirms the statement that de novo synthesis of DA is suppressed under stress conditions. The increased activities of MAO B, as well as the increased level of COMT protein, are believed to be related to intensified DA catabolism conditions. Also, a decreased activity of GPx in the hippocampus of chronically stressed animals was found. The increased enzymatic activity of MAO B negatively correlated with the reduced activity of GPx under the above-mentioned stress conditions. These events in the hippocampus of chronically stressed animals could synergistically cause oxidative damage to the mitochondria. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.

The role of mitochondria is multidimensional and ranges in vast areas, including apoptosis, cellular response towards stress, metabolism, which is regulated by a plethora of proteins, acting together to maintain cellular and organellar homeostasis. In spite of the presence of mitochondrial DNA, most of the mitochondrial proteins are nuclear encoded and translocated inside the organelle through dedicated translocases present on outer and inner membrane of mitochondria. To fulfil the cellular energy demand, mitochondria efficiently generate ATP by oxidative phosphorylation, and thus are considered as "power house of cell." There occurs a transfer of electrons from various oxidizable substrates to oxygen, which is achieved by a series of redox reactions with generation of water as a byproduct. This process is coupled with ATP synthesis, involves five protein-complexes present in the inner mitochondrial membrane. During this process, it generates extremely reactive intermediate species of oxygen as a byproduct collectively referred as Reactive Oxygen Species (ROS) through partial reduction of oxygen. These intermediate metabolites of oxygen include superoxide anion (O2-º), H2O2 and highly reactive hydroxyl radicals (OHº). Although ROS are produced by different cellular sources, such as widely expressed and evolutionary conserved NADPH Oxidases, xanthine oxidase, cyclooxygenases, lipoxygenases and cytochrome P450 enzymes but mitochondria are one of the major contributors of cellular ROS. Earlier, reactive oxygen species were considered as harmful but for past few decades, the role ROS has been appreciated as signalling molecules. Because of their high reactivity, these species can cause redox mediated modifications to cellular components and thus have an ability to participate in signalling process. The regulation of signalling pathway by ROS is governed by either alterations in cellular redox conditions or by oxidative modifications of certain residues in proteins, whic

The present study was conducted to assess effects of selenium (Se)-yeast supplementation on glutathione peroxidase activity, Se levels in tissues, growth performance, carcass, and meat composition in broilers. A total of 275 one-d-old Cobb 500 broilers of both sexes were randomly allotted to 1 of 5 treatments during a 42-d period. The 5 treatments differed only in Se content: group 1 had no additional Se (background only); groups 2, 3, and 4 received 0.3 mg/kg of added Se from the beginning of the trial until d 21, whereas in the second half of the study (from d 22 to 42), these groups received 0.3, 0.6, and 0.9 mg/kg of added Se, respectively; and group 5 received 0.9 mg/kg of Se for the entire experimental period. At the end of the study, the control group showed significantly lower (P < 0.01) glutathione peroxidase activity in blood plasma compared to Se-supplemented groups. Regarding Se concentration in various tissues, the groups receiving Se yeast showed higher plasma, feces, and meat Se contents than the control group (P < 0.01). Supplementation of Se improved broilers body weight, weight gain and feed conversion ratio (P < 0.01). Dressing percentage was lower in the control group and the group with 0.3 mg/kg of added Se compared to other experimental groups (0.6 and 0.9 mg/kg of dietary Se). The proportion of less valuable carcass parts (wings and legs) was higher (P < 0.01) in the group fed the basal diet compared to groups supplemented with 0.9 mg/kg of Se. Initial and ultimate pH values differed among experimental groups (P < 0.05). Supplementation of Se improved the broilers antioxidative resistance, growth performance, carcass quality, and chemical composition of meat.

Today, a few differing sources of selenium (Se), i.e. inorganic, organic, and nano forms of Se, are used as feed supplements for poultry. Published research indicates that nano-Se and organic Se possess comparable efficiency to inorganic Se in increasing GSH-Px activity of plasma and various tissues, but they deposit at higher rates in various tissues. However, there are principal differences in absorption mechanisms, metabolism, and efficiency of these three forms of Se. The aim of this review was to analyze the available literature on the effects of different Se sources and levels in the diet on glutathione peroxidase (GSH-Px) activity, tissue Se distribution and growth performance in poultry. Higher levels of Se increase GSH-Px activity in the body, but this reaches a plateau even if Se concentrations in diet increase further, while the deposition of Se in tissues increases as Se content in diet increases. In addition, many studies have shown the positive effects of adding Se to diet on growth performance in poultry. Optimal Se supplementation is necessary not only for good poultry health but also to ensure and preserve meat quality during storage and to provide human beings with this microelement.

The effects of chronic restraint stress (CRS, 2 h during 14 days) on gene expression of tyrosine hydroxylase (TH), catechol-O-methyltransferase (COMT), and glutathione peroxidase (GPx) were studied in the rat hippocampus. Changes in the dopamine (DA) concentration and activities of monoamine oxidases (MAO A and MAO B) and GPx in this cerebral structure of chronically stressed rats were also examined. The investigated parameters were quantified using real-time RT-PCR, Western blot analyses, and assay of enzymatic activity. We found that CRS decreased the TH protein level and DA concentration, which probably confirms the statement that de novo synthesis of DA is suppressed under stress conditions. The increased activities of MAO B, as well as the increased level of COMT protein, are believed to be related to intensified DA catabolism conditions. Also, a decreased activity of GPx in the hippocampus of chronically stressed animals was found. The increased enzymatic activity of MAO B negatively correlated with the reduced activity of GPx under the above-mentioned stress conditions. These events in the hippocampus of chronically stressed animals could synergistically cause oxidative damage to the mitochondria. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.

Background: Selenium is an essential trace element and is suggested to play a role in the etiology of a number of chronic diseases. Genetic variation in genes encoding selenoproteins, such as selenoprotein P and the glutathione peroxidases, may affect selenium status and, thus, individual susceptibility to some chronic diseases. In the present study, we aimed to (1) investigate the effect of mussel and fish intake on glutathione peroxidase enzyme activity and (2) examine whether single nucleotide polymorphisms in the GPX1, GPX4, and SELENOP genes modify the effect of mussel and fish intake for 26 weeks on whole blood selenium, plasma selenoprotein P concentrations, and erythrocyte GPX enzyme activity in a randomized intervention trial in Denmark. Results: CC homozygotes of the SELENOP/rs3877899 polymorphism who consumed 1000 g fish and mussels per week for 26 consecutive weeks had higher levels of both selenoprotein P (difference between means - 4.68 ng/mL (95% CI - 8.49, - 0.871)) and whole blood selenium (difference between means - 5.76 (95% CI - 12.5, 1.01)) compared to fish and mussel consuming T-allele carriers although the effect in whole blood selenium concentration was not statistically significant. Conclusions: Our study indicates that genetically determined variation in SELENOP leads to different responses in expression of selenoproteins following consumption of selenium-rich foods. This study also emphasizes the importance of taking individual aspects such as genotypes into consideration when assessing risk in public health recommendations.

Major depressive disorder (MDD) has been linked to mitochondrial defects, which could manifest in mitochondrial DNA (mtDNA) polymorphisms or mutations. Additionally, copy number of mtDNA (mtDNA-cn) can be quantified in peripheral blood mononuclear cells (PBMC)s, indirectly reflecting cellular energetics, or in the circulating cell-free mtDNA (ccf-mtDNA) levels, which may reflect a fraction of the mitochondrial genome released during cellular stress. Few studies have examined ccf-mtDNA in MDD, and no studies have tested its relationship with intracellular mtDNA-cn or with antidepressant treatment response. Here, mtDNA levels were quantified in parallel from: (i) PBMCs and (ii) cell-free plasma of 50 unmedicated MDD subjects and 55 controls, in parallel with PBMC telomere length (TL) and antioxidant enzyme glutathione peroxidase (GpX) activity. MtDNA measures were repeated in 19 MDD subjects after 8 weeks of open-label SSRI treatment. In analyses adjusted for age, sex, BMI, and smoking, MDD subjects had significantly elevated levels of ccf-mtDNA (F = 20.6, p = 0.00002). PBMC mtDNA-cn did not differ between groups (p > 0.4). In preliminary analyses, we found that changes in ccf-mtDNA with SSRI treatment differed between SSRI responders and non-responders (F = 6.47, p = 0.02), with the non-responders showing an increase in ccf-mtDNA and responders not changing. Baseline ccf-mtDNA was positively correlated with GpX (r = 0.32, p = 0.001), and PBMC mtDNA correlated positively with PBMC TL (r = 0.38, p = 0.0001). These data suggest that plasma ccf-mtDNA and PBMC mtDNA-cn reflect different cellular processes and that the former may be more reflective of certain aspects of MDD pathophysiology and of the response to SSRI antidepressants.

Background:Oxidative stress is responsible for some alterations in the chemical structure and, consequently, in the function of proteins, lipids, and DNA. Recent studies have linked oxidative stress to cancers, particularly thyroid cancer, but the mechanisms remain unclear. Here, we further characterize the role of oxidative stress in thyroid cancer by analyzing the expression of two selenium antioxidant molecules, glutathione peroxidase (GPx1) and thioredoxin reductase (TrxR1) in thyroid cancer cells. Methods:Samples of both healthy thyroid tissue and thyroid tumor were taken for analysis after total thyroidectomy. The expression of GPx1 and TrxR1 was revealed by Western blot analysis and quantified by densitometric analyses, while the evaluation of free radicals was performed by Electron Paramagnetic Resonance (EPR)-spin trapping technique. Results:Our results show a decrease in the expression of GPx1 and TrxR1 (- 45.7 and - 43.2% respectively, p < 0.01) in the thyroid cancer cells compared to the healthy cells. In addition, the EPR technique shows an increase of free radicals in tumor tissue, significantly higher than that found in healthy thyroid tissue (+ 116.3%, p < 0.01). Conclusions:Our findings underscore the relationship between thyroid cancer and oxidative stress, showing the imbalance of the oxidant/antioxidant system in thyroid cancer tissue. These results suggest that either the inability to produce adequate antioxidant defense or an increased consumption of antioxidants, due to the hyper-production of free radicals, may play a crucial role in thyroid cancer.