RESUMO

The aim of this study was to evaluate the effects of forced molting using biochemical parameters and histopathological findings in laying hens. 36 Hyline W36 strain laying hens, 90 weeks old were chosen for this research. Eight of these chickens were randomly selected and placed in a cage as the control group before the molting program began. All the others 28 chickens were used for the forced molting program. Eight laying hens were slaughtered at the end of the molting program named as molting group. The remaining 20 hens were fed for 37 days, weighted and slaughtered when they reached the maximum egg production (80%) as postmolting group. Then, blood was analyzed for malondialdehyde, glutathione, catalase, glucose, calcium, phosphorus, albumin, globulin, total protein, triiodothyronine, thyroxine and Vitamin C. The malondialdehyde and glutathione levels of the thyroid and liver tissues were also analyzed along with an examination of the histopathological changes of the liver, ovarium and thyroid glands; and live body, liver, ovarium, thyroid weights and thyroid lengths. In conclusion, it was found that forced molting produces stress and notable side effects in hens, like the oxidant and antioxidant status of the organs, tissue weights and sizes, hormon profiles, blood biochemical and histopathological parameter changes. The activities of thyroid malondialdehyde (p 0.05), liver glutathione (p 0.01), plasma catalase (p 0.001) were significantly decreased in molting group compared to control values, while liver malondialdehyde levels were significantly increased (p 0.001) and thyroid glutathione levels had nonsignificant effect. These levels in molting hens were the first study for veterinary science.(AU)

Assuntos

Animais , Fenômenos Bioquímicos , Fenômenos Bioquímicos , Galinhas/metabolismo , Galinhas/fisiologia , Muda/fisiologia , Plumas/lesões , Antioxidantes/análise , Ovário/fisiologia , Glândula Tireoide/fisiologia , Coleta de Amostras Sanguíneas/veterinária , Testes Hematológicos/veterinária , Glutationa/análise , Malondialdeído/análise , Catalase/fisiologia , Glucose/fisiologia

RESUMO

The aim of this study was to evaluate the effects of forced molting using biochemical parameters and histopathological findings in laying hens. 36 Hyline W36 strain laying hens, 90 weeks old were chosen for this research. Eight of these chickens were randomly selected and placed in a cage as the control group before the molting program began. All the others 28 chickens were used for the forced molting program. Eight laying hens were slaughtered at the end of the molting program named as molting group. The remaining 20 hens were fed for 37 days, weighted and slaughtered when they reached the maximum egg production (80%) as postmolting group. Then, blood was analyzed for malondialdehyde, glutathione, catalase, glucose, calcium, phosphorus, albumin, globulin, total protein, triiodothyronine, thyroxine and Vitamin C. The malondialdehyde and glutathione levels of the thyroid and liver tissues were also analyzed along with an examination of the histopathological changes of the liver, ovarium and thyroid glands; and live body, liver, ovarium, thyroid weights and thyroid lengths. In conclusion, it was found that forced molting produces stress and notable side effects in hens, like the oxidant and antioxidant status of the organs, tissue weights and sizes, hormon profiles, blood biochemical and histopathological parameter changes. The activities of thyroid malondialdehyde (p 0.05), liver glutathione (p 0.01), plasma catalase (p 0.001) were significantly decreased in molting group compared to control values, while liver malondialdehyde levels were significantly increased (p 0.001) and thyroid glutathione levels had nonsignificant effect. These levels in molting hens were the first study for veterinary science.

Assuntos

Animais , Fenômenos Bioquímicos , Galinhas/fisiologia , Galinhas/metabolismo , Muda/fisiologia , Plumas/lesões , Antioxidantes/análise , Catalase/fisiologia , Coleta de Amostras Sanguíneas/veterinária , Glucose/fisiologia , Glutationa/análise , Glândula Tireoide/fisiologia , Malondialdeído/análise , Ovário/fisiologia , Testes Hematológicos/veterinária

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is directly associated with insulin resistance and oxidative stress. In NAFLD is established a reduction in n-3 LCPUFA (EPA + DHA) levels and hepatic activity of transcription factor PPAR-alpha. EPA and DHA inhibit lipogenesis and stimulate fatty acid oxidation in the liver. Extra virgin olive oil (EVOO) has important antioxidant properties. This study evaluated the prevention of insulin resistance and prevention of depletion of hepatic antioxidant defense inC57BL/6J mice fed high-fat diet (HFD), supplemented with n-3 LCPUFA plus EVOO. HFD generated insulin resistance and hepatic steatosis, together with significant reduction in i) n-3 LCPUFA hepatic levels, ii) DNA binding activity of PPAR-alpha, iii) activity of antioxidant enzymes (catalase and superoxide dismutase), respect to control group (fed with control diet). Supplementation with n-3 LCPUFA plus EVOO prevent development insulin resistance and attenuate increased of fat in liver (p < 0.05), together with a normalization of i) DNA binding activity of PPAR-á, ii) activity of antioxidant enzymes (catalase and superoxide dismutase) and iii) reducing depletion of n-3 LCPUFA levels in liver tissue, compared to the control group (p < 0.05). Supplementation with n-3 LCPUFA plus EVOO reduced hepatic steatosis and prevent development of insulin resistance, along with preserving the antioxidant defense in liver. Projecting the use of this mixture of AGPICL n-3 plus EVOO as a potential treatment of NAFLD.

Assuntos

Masculino , Animais , Camundongos , Azeite de Oliva/uso terapêutico , /uso terapêutico , Dieta Hiperlipídica , Suplementos Nutricionais , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Azeite de Oliva/farmacologia , /farmacologia , Catalase , Catalase/fisiologia , Fígado , Estresse Oxidativo , Superóxido Dismutase

RESUMO

Background: The unavoidable consequence of ageing process is oxidative stress which is harmful to cells. Muscles asa post-mitotic cells are especially susceptible for it. They are protected by antioxidants. One of the main antioxidantenzymes is catalase (CAT). Although muscles were extensively examined for antioxidant defense, there is a lack of comparative study regarding CAT activity in skeletal muscles, heart muscle and diaphragm in cows. The aim of present studywas investigate the link between age related alterations and antioxidant defense system and confirmation that CAT activitydepends on age and type of muscle tissue dependent on metabolic rate.Materials, Methods & Results: Samples of skeletal muscles, heart and diaphragm were collected from healthy HolsteinFriesian cows aged between 14 and 27 months (n = 12; sexually mature) and female calves aged between 2 weeks and 2months (n = 9; sexually immature) in slaughterhouse. The enzyme activity was measured by spectrophotometric method.Additionally the presence of CAT was confirmed by SDS-PAGE separation and detected by zymography. In current investigation CAT activity in heart and diaphragm showed significantly higher (P < 0.05) values than in skeletal muscles.Moreover, CAT activity was higher in cows than in calves in heart (0.28 ± 0.044 U /mg protein vs. 0.4 ± 0.035) as well asin diaphragm (0.27 ± 0.047 vs 0.37 ± 0.077), however in skeleton muscles there were no significant differences betweenexamined animals (0.076 ± 0.016 vs 0.084 ± 0.0197). According to received results CAT activity increased during agingin heart and diaphragm while in skeleton muscles age-related changes were not observed.Discussion: Skeletal muscles are particularly vulnerable to oxidative stress because...(AU)

Assuntos

Animais , Bovinos , Fatores Etários , Catalase/fisiologia , Músculos/fisiologia , Metabolismo Basal , Diafragma , Envelhecimento/fisiologia , Estresse Oxidativo

RESUMO

Background: The unavoidable consequence of ageing process is oxidative stress which is harmful to cells. Muscles asa post-mitotic cells are especially susceptible for it. They are protected by antioxidants. One of the main antioxidantenzymes is catalase (CAT). Although muscles were extensively examined for antioxidant defense, there is a lack of comparative study regarding CAT activity in skeletal muscles, heart muscle and diaphragm in cows. The aim of present studywas investigate the link between age related alterations and antioxidant defense system and confirmation that CAT activitydepends on age and type of muscle tissue dependent on metabolic rate.Materials, Methods & Results: Samples of skeletal muscles, heart and diaphragm were collected from healthy HolsteinFriesian cows aged between 14 and 27 months (n = 12; sexually mature) and female calves aged between 2 weeks and 2months (n = 9; sexually immature) in slaughterhouse. The enzyme activity was measured by spectrophotometric method.Additionally the presence of CAT was confirmed by SDS-PAGE separation and detected by zymography. In current investigation CAT activity in heart and diaphragm showed significantly higher (P < 0.05) values than in skeletal muscles.Moreover, CAT activity was higher in cows than in calves in heart (0.28 ± 0.044 U /mg protein vs. 0.4 ± 0.035) as well asin diaphragm (0.27 ± 0.047 vs 0.37 ± 0.077), however in skeleton muscles there were no significant differences betweenexamined animals (0.076 ± 0.016 vs 0.084 ± 0.0197). According to received results CAT activity increased during agingin heart and diaphragm while in skeleton muscles age-related changes were not observed.Discussion: Skeletal muscles are particularly vulnerable to oxidative stress because...

Assuntos

Animais , Bovinos , Catalase/fisiologia , Diafragma , Fatores Etários , Metabolismo Basal , Músculos/fisiologia , Envelhecimento/fisiologia , Estresse Oxidativo

RESUMO

Several biological processes are involved in the oxidative stress present in diabetes mellitus; among them we can find glucose autooxidation, proteins glycation and decreased antioxidant defenses. Free radicals yielded at mitochondrial level could be a trigger to unchain the vicious circle of the oxidative stress in diabetes mellitus. Aims: to determine antioxidant system’s alterations and indicators of oxidative damage on lipids and proteins in patients with type II Diabetes and a control group. Materials and Methods: It was analyzed 120 serum samples; 60 from patients that suffer type II diabetic from endocrinology surgery belonging “Casa de atención al paciente diabético”in Santa Clara, Villa Clara and 60 samples from healthy individuals used as control group. Spectrofotometric techniques were used to assess levels of Superoxide dismutase and Catalase activity as well as concentrations of reduced glutathione, malonildialdehide and advanced products of proteins Oxidation. Results were compared using the statistical software SPSS. Results: Diabetes type 2 patients showed decreased of Superoxide Dismutase and Catalase enzymatic activity (p = 0,003) and (p = 0,013) respectively as well as and reduced Glutathione levels (p = 0,038). Malondialdehide and Advanced Products of Proteins Oxidation were increased (p = 0,000) in diabetics patients compared with control group. Conclusions: it was found redox alterations in patients that suffer type 2 Diabetes. These alterations are evidenced by a reduced antioxidant enzymatic system and damage on macromolecules such as lipids and proteins...

Assuntos

Humanos , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , /enzimologia , /metabolismo , Estresse Oxidativo/fisiologia , Antioxidantes/fisiologia , Estudos de Casos e Controles , Catalase/fisiologia , /sangue , Radicais Livres , Glutationa/sangue , Malondialdeído/sangue , Superóxido Dismutase/fisiologia

RESUMO

Antioxidant enzymes seem to play roles in controlling the luteal function and the luteolytic action of prostaglandin F2 α (PGF). The aim of this study was to clarify the roles of catalase (CAT) and glut athione peroxidase (GPx) in the luteolytic action of PGF in both corpus luteum (CL) and cultured luteal cells. Corpora lutea were collected at the early ( days 2 - 3), developing ( days5 - 6), mid ( days8 - 12), late ( days15 - 17) and regressed ( days19 - 21) luteal stages (n = 5 CL/stage) and at 0 , 2 and 24 h after luteolytic PGF administration (0 h) on d ay 10 (n = 5 cows / time point ) . Catalase protein and the activities of CAT and GPx increased from the early to mid - luteal stage, then all decreased (P < 0.05), reaching their lowest levels at the regressed luteal stage. The levels of GPx1 protein were lower in the regressed luteal stage than in other stages (P < 0.05). Immunohistochemical examination also revealed the expression of CAT and GPx1 protein in the bovine C L tissue. Injection of a luteolytic dose of PGF increased luteal GPx1 protein and GPx activities at 2 h but suppressed them at 24 h. Catalase protein and CAT activity did not change at 2 h but CAT activity decreased (P < 0.05) at 24 h. Prostagla ndin F2α (1 μ M ) and H 2 O 2 (10 μ M ) decreased CAT and GPx1 protein expression and activity at 24 h in cultured luteal cells isolated from mid - luteal stage CL (n = 3 CL per each experiment). Interestingly, CAT protein and activity did not change while GPx1 protein and activity increased at 2 h in luteal cells treated with PGF and H 2 O 2 (P < 0.05). The down - regulation of CAT and GPx, and their activities during structural luteolysis might enhance the accumulation of reactive oxygen species, which would result in both increasing luteal PGF production and cell death to complete CL regression in cattle. (AU)

Assuntos

Animais , Feminino , Bovinos , Corpo Lúteo/enzimologia , Células Cultivadas/enzimologia , Células Lúteas/enzimologia , Dinoprosta/fisiologia , Glutationa Peroxidase/fisiologia , Catalase/fisiologia , Antioxidantes/metabolismo , Ciclo Estral

RESUMO

Antioxidant enzymes seem to play roles in controlling the luteal function and the luteolytic action of prostaglandin F2 α (PGF). The aim of this study was to clarify the roles of catalase (CAT) and glut athione peroxidase (GPx) in the luteolytic action of PGF in both corpus luteum (CL) and cultured luteal cells. Corpora lutea were collected at the early ( days 2 - 3), developing ( days5 - 6), mid ( days8 - 12), late ( days15 - 17) and regressed ( days19 - 21) luteal stages (n = 5 CL/stage) and at 0 , 2 and 24 h after luteolytic PGF administration (0 h) on d ay 10 (n = 5 cows / time point ) . Catalase protein and the activities of CAT and GPx increased from the early to mid - luteal stage, then all decreased (P < 0.05), reaching their lowest levels at the regressed luteal stage. The levels of GPx1 protein were lower in the regressed luteal stage than in other stages (P < 0.05). Immunohistochemical examination also revealed the expression of CAT and GPx1 protein in the bovine C L tissue. Injection of a luteolytic dose of PGF increased luteal GPx1 protein and GPx activities at 2 h but suppressed them at 24 h. Catalase protein and CAT activity did not change at 2 h but CAT activity decreased (P < 0.05) at 24 h. Prostagla ndin F2α (1 μ M ) and H 2 O 2 (10 μ M ) decreased CAT and GPx1 protein expression and activity at 24 h in cultured luteal cells isolated from mid - luteal stage CL (n = 3 CL per each experiment). Interestingly, CAT protein and activity did not change while GPx1 protein and activity increased at 2 h in luteal cells treated with PGF and H 2 O 2 (P < 0.05). The down - regulation of CAT and GPx, and their activities during structural luteolysis might enhance the accumulation of reactive oxygen species, which would result in both increasing luteal PGF production and cell death to complete CL regression in cattle.

Assuntos

Feminino , Animais , Bovinos , Catalase/fisiologia , Corpo Lúteo/enzimologia , Células Cultivadas/enzimologia , Células Lúteas/enzimologia , Dinoprosta/fisiologia , Glutationa Peroxidase/fisiologia , Antioxidantes/metabolismo , Ciclo Estral

RESUMO

PURPOSE: To assess oxidative stress and the profile of fatty acids incorporated into the hepatic tissue of animals refed with high-fat (HF) diets after acute food restriction. METHODS: Fifty male Wistar rats were divided into five groups and fasting for 48 hours. One group was sacrificed without refeeding (NR), a control group (C) was refed with the standard AIN-93 diet and the remaining groups with HF diets respectively consisting of hydrogenated vegetable oil (PHVO), trans-free (TF) margarine and trans-free margarine enriched with ω-3 and ω-6 (O). After this period the animals were sacrificed for malondialdehyde (MDA), catalase and hepatic fatty acid determination. RESULTS: The groups refed with HF diets showed elevation of MDA levels compared to the C group (p<0.001 for GVH and p<0.01 for TF and O). Hepatic catalase activity was higher in the TF and O groups compared to group C (p<0.05 for both). The amount of saturated fatty acids was lower in the PHVO and O groups compared to the remaining ones (p<0.001). CONCLUSION: The consumption of high-fat diets after prolonged fasting favors oxidative imbalance in hepatic tissue.

Assuntos

Dieta Hiperlipídica , Jejum/fisiologia , Ácidos Graxos/análise , Fígado/metabolismo , Estresse Oxidativo/fisiologia , Animais , Catalase/fisiologia , Fígado Gorduroso/metabolismo , Fígado/química , Masculino , Malondialdeído/análise , Modelos Animais , Distribuição Aleatória , Ratos , Ratos Wistar , Valores de Referência , Fatores de Tempo

RESUMO

FUNDAMENTO: A menopausa pode levar a alterações na saúde feminina, com mudanças no estado oxidativo de mulheres pós-menopausadas, para as quais são limitadas as informações relativas à influência da hormonioterapia (HT) sobre as atividades das enzimas antioxidantes. OBJETIVO: Avaliar a influência da HT sobre a atividade da catalase, concentrações de lipídeos e lipoproteínas, proteína de transferência de colesteril éster, substâncias reativas ao ácido tiobarbitúrico, nitratos, proteína C-reativa ultrassensível e espessura da carótida em mulheres pós-menopausadas. MÉTODOS: Foram alocadas 94 mulheres para um de quatro grupos com ou sem HT. O último grupo foi subdividido em mulheres sendo tratadas com estrógeno e outras com estrógeno mais progestágeno. Foram realizadas medidas de parâmetros bioquímicos plasmáticos e da espessura da íntima-média da carótida. RESULTADOS: A HT antagonizou a redução na atividade da catalase após a menopausa, mas não teve efeito sobre os níveis da proteína de transferência de colesteril éster, substâncias reativas ao ácido tiobarbitúrico, peróxido lipídico, nitrato e proteína C reativa ultrassensível, nem sobre a espessura da íntima-média da carótida. A análise multivariada mostrou que a HT baseada em estrógeno atenuou a relação entre os fatores de risco cardiovasculares e a espessura da íntima-média da carótida comum. CONCLUSÃO: Este estudo mostra que a HT em mulheres pós-menopausadas produz efeitos antioxidantes e antiateroscleróticos benéficos por melhorar as concentrações séricas de lipídios e lipoproteínas, aumentar a atividade da catalase sérica e atenuar a associação entre os fatores de risco cardiovasculares e a aterosclerose precoce.

---

BACKGROUND: Menopause can lead to alterations in women's health, with changes in the oxidative status of postmenopausal women in whom information regarding the influence of hormone therapy (HT) on antioxidant enzyme activities is limited. OBJECTIVE: To evaluate the influence of HT on catalase activity; concentrations of lipids and lipoprotein, cholesteryl ester transfer protein, thiobarbituric acid-reactive substances, nitrates, high-sensitivity C-reactive protein and carotid thickness in postmenopausal women. METHODS: Ninety-four consecutive women were allocated to one of four groups, without HT and with HT. The latter group was subdivided into women using estrogen and those using estrogen plus progestogen therapy. Plasma biochemical parameters and common carotid intima-media thickness measurements were performed. RESULTS: HT antagonized the decrease in catalase activity after menopause, but had no effect on the levels of cholesteryl ester transfer protein, thiobarbituric acid-reactive substances, lipid peroxide, nitrate, high-sensitivity C-reactive protein, or on the common carotid intima-media thickness. Multivariate analysis showed that estrogen-based HT attenuated the relationship between cardiovascular risk factors and the intima-media thickness of the common carotid. CONCLUSION: This study indicates that HT in postmenopausal women produces beneficial antioxidant and anti-atherosclerotic effects by ameliorating the plasma lipid and lipoprotein profiles, increasing plasma catalase activity and attenuating the association between cardiovascular risk factors and early atherosclerosis.

Assuntos

Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Doenças Cardiovasculares/prevenção & controle , Catalase/metabolismo , Terapia de Reposição de Estrogênios , Pós-Menopausa/sangue , Biomarcadores/sangue , Pressão Sanguínea/efeitos dos fármacos , Proteínas Sanguíneas/análise , Doenças Cardiovasculares/metabolismo , Catalase/fisiologia , Lipídeos/sangue , Estresse Oxidativo/efeitos dos fármacos , Pós-Menopausa/efeitos dos fármacos , Fatores de Risco , Estatísticas não Paramétricas , Resultado do Tratamento

RESUMO

BACKGROUND: Menopause can lead to alterations in women's health, with changes in the oxidative status of postmenopausal women in whom information regarding the influence of hormone therapy (HT) on antioxidant enzyme activities is limited. OBJECTIVE: To evaluate the influence of HT on catalase activity; concentrations of lipids and lipoprotein, cholesteryl ester transfer protein, thiobarbituric acid-reactive substances, nitrates, high-sensitivity C-reactive protein and carotid thickness in postmenopausal women. METHODS: Ninety-four consecutive women were allocated to one of four groups, without HT and with HT. The latter group was subdivided into women using estrogen and those using estrogen plus progestogen therapy. Plasma biochemical parameters and common carotid intima-media thickness measurements were performed. RESULTS: HT antagonized the decrease in catalase activity after menopause, but had no effect on the levels of cholesteryl ester transfer protein, thiobarbituric acid-reactive substances, lipid peroxide, nitrate, high-sensitivity C-reactive protein, or on the common carotid intima-media thickness. Multivariate analysis showed that estrogen-based HT attenuated the relationship between cardiovascular risk factors and the intima-media thickness of the common carotid. CONCLUSION: This study indicates that HT in postmenopausal women produces beneficial antioxidant and anti-atherosclerotic effects by ameliorating the plasma lipid and lipoprotein profiles, increasing plasma catalase activity and attenuating the association between cardiovascular risk factors and early atherosclerosis.

Assuntos

Doenças Cardiovasculares/prevenção & controle , Catalase/metabolismo , Terapia de Reposição de Estrogênios , Pós-Menopausa/sangue , Idoso , Biomarcadores/sangue , Pressão Sanguínea/efeitos dos fármacos , Proteínas Sanguíneas/análise , Doenças Cardiovasculares/metabolismo , Catalase/fisiologia , Feminino , Humanos , Lipídeos/sangue , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Pós-Menopausa/efeitos dos fármacos , Fatores de Risco , Estatísticas não Paramétricas , Resultado do Tratamento

RESUMO

Most fungi have several monofunctional heme-catalases. Filamentous ascomycetes (Pezizomycotina) have two types of large-size subunit catalases (L1 and L2). L2-type are usually induced by different stressors and are extracellular enzymes; those from the L1-type are not inducible and accumulate in asexual spores. L2 catalases are important for growth and the start of cell differentiation, while L1 are required for spore germination. In addition, pezizomycetes have one to four small-size subunit catalases. Yeasts (Saccharomycotina) do not have large-subunit catalases and generally have one peroxisomal and one cytosolic small-subunit catalase. Small-subunit catalases are inhibited by substrate while large-subunit catalases are activated by H(2)O(2). Some small-subunit catalases bind NADPH preventing inhibition by substrate. We present a phylogenetic analysis revealing one or two events of horizontal gene transfers from Actinobacteria to a fungal ancestor before fungal diversification, as the origin of large-size subunit catalases. Other possible horizontal transfers of small- and large-subunit catalases genes were detected and one from bacteria to the fungus Malassezia globosa was analyzed in detail. All L2-type catalases analyzed presented a secretion signal peptide. Mucorales preserved only L2-type catalases, with one containing a secretion signal if two or more are present. Basidiomycetes have only L1-type catalases, all lacking signal peptide. Fungal small-size catalases are related to animal catalases and probably evolved from a common ancestor. However, there are several groups of small-size catalases. In particular, a conserved group of fungal sequences resemble plant catalases, whose phylogenetic origin was traced to a group of bacteria. This group probably has the heme orientation of plant catalases and could in principle bind NADPH. From almost a hundred small-subunit catalases only one fourth has a peroxisomal localization signal and in fact many fungi lack a peroxisomal catalase. Catalases have a deep buried active site and H(2)O(2) has to go through a long passage to reach it. In all known structures of catalases, the major channel has common features, particularly in the straight and narrow final section that is positioned perpendicular to the heme. Besides, other conserved channels are present in catalases whose function remains to be elucidated. One of these channels intercommunicates the major channels from the two R-related subunits. In three of the four known large-subunits catalase structures, the heme b is partially transformed into heme d. In Neurospora crassa, this occurs in vivo and is related to oxidative stress conditions in which singlet oxygen is produced. A pure source of singlet oxygen oxidizes catalases purified from different sources and singlet oxygen quenchers prevent oxidation. A second modification is observed in N. crassa catalase-1, in which the tyrosine that forms the fifth coordination bound to the heme iron makes a covalent bond with a vicinal cysteine, similarly to the tyrosine-histidine bonding found in Escherichia coli hydroperoxidase II. Molecular dynamics has been used to determine how H(2)O(2) reaches the enzyme active site and how products exit the protein. We found that the bottleneck of the major channel seems to disappear in water and is wide open in the presence of substrate. Amino acid residues exhibiting an increased residence time for H(2)O(2) are abundant at the protein surface and at the entrances to the major channel. The net effect of this is an increased H(2)O(2)/H(2)O ratio in the major channel. Once in the final section of this channel, H(2)O(2) is retained and tends to occupy specific sites while water molecules have a higher turnover rate and occupy different sites. Despite the intense study of catalases our knowledge of this enzyme is still limited and in need of new studies and different approaches.

Assuntos

Catalase/química , Catalase/fisiologia , Fungos/enzimologia , Ascomicetos/enzimologia , Catalase/genética , Domínio Catalítico , Diferenciação Celular , Simulação por Computador , Regulação Enzimológica da Expressão Gênica , Heme/química , Peróxido de Hidrogênio/química , Cinética , Conformação Molecular , Simulação de Dinâmica Molecular , Peroxidase/química , Filogenia , Conformação Proteica

RESUMO

Nitrogen-fixing bacteria collectively called rhizobia are adapted to live in polyphenol-rich environments. The mechanisms that allow these bacteria to overcome toxic concentrations of plant polyphenols have not been clearly elucidated. We used a crude extract of polyphenols released from the seed coat of the black bean to simulate a polyphenol-rich environment and analyze the response of the bean-nodulating strain Rhizobium etli CFN42. Our results showed that the viability of the wild type as well as that of derivative strains cured of plasmids p42a, p42b, p42c, and p42d or lacking 200 kb of plasmid p42e was not affected in this environment. In contrast, survival of the mutant lacking plasmid p42f was severely diminished. Complementation analysis revealed that the katG gene located on this plasmid, encoding the only catalase present in this bacterium, restored full resistance to testa polyphenols. Our results indicate that oxidation of polyphenols due to interaction with bacterial cells results in the production of a high quantity of H(2)O(2), whose removal by the katG-encoded catalase plays a key role for cell survival in a polyphenol-rich environment.

Assuntos

Proteínas de Bactérias/fisiologia , Catalase/fisiologia , Flavonoides/toxicidade , Viabilidade Microbiana , Fenóis/toxicidade , Plasmídeos , Rhizobium etli/enzimologia , Rhizobium etli/fisiologia , Proteínas de Bactérias/genética , Catalase/genética , Contagem de Colônia Microbiana , Fabaceae/microbiologia , Flavonoides/metabolismo , Teste de Complementação Genética , Fenóis/metabolismo , Extratos Vegetais/toxicidade , Polifenóis , Rhizobium etli/genética

RESUMO

Aiming to clarify the mechanisms by which eukaryotes acquire tolerance to oxidative stress, adaptive and cross-protection responses to oxidants were investigated in Saccharomyces cerevisiae. Cells treated with sub-lethal concentrations of menadione (a source of superoxide anions) exhibited cross-protection against lethal doses of peroxide; however, cells treated with H2O2 did not acquire tolerance to a menadione stress, indicating that menadione response encompasses H2O2 adaptation. Although, deficiency in cytoplasmic superoxide dismutase (Sod1) had not interfered with response to superoxide, cells deficient in glutathione (GSH) synthesis were not able to acquire tolerance to H2O2 when pretreated with menadione. These results suggest that GSH is an inducible part of the superoxide adaptive stress response, which correlates with a decrease in the levels of intracellular oxidation. On the other hand, neither the deficiency of Sod1 nor in GSH impaired the process of acquisition of tolerance to H2O2 achieved by a mild pretreatment with peroxide. Using a strain deficient in the cytosolic catalase, we were able to conclude that the reduction in lipid peroxidation levels produced by the adaptive treatment with H2O2 was dependent on this enzyme. Corroborating these results, the pretreatment with low concentrations of H2O2 promoted an increase in catalase activity.

Assuntos

Catalase/fisiologia , Glutationa/fisiologia , Peróxido de Hidrogênio/toxicidade , Estresse Oxidativo , Saccharomyces cerevisiae/metabolismo , Superóxido Dismutase/fisiologia , Vitamina K 3/toxicidade , Adaptação Fisiológica , Dissulfeto de Glutationa/fisiologia

RESUMO

Acidic mine waters have a marked influence on the surrounding environment and pose a serious threat through long-term environmental degradation. Therefore, it is important to improve and monitor water quality with the aim of decreasing the hazard presented by this effluent emission. The aim of this work was to evaluate the remediation of mining wastewater effluents by chitosan microspheres using biomarkers of exposure and effect. DNA damage (Comet assay) and several biomarkers of oxidative stress, such as lipoperoxidation levels (TBARS), superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) activities, and contents of reduced glutathione (GSH), were measured in blood and liver of tilapia (Oreochromis niloticus) exposed for 7, 15, and 30 days to dechlorinated tap water, 10% coal mining wastewater (CMW), and coal mining wastewater treated with chitosan microspheres (RCM). The results indicate that hepatic TBARS levels were significantly higher in fish exposed to CMW after 7, 15, and 30 days (100%, 86%, and 63%, respectively), and after remediation there was no significant difference in relation to the control group. Hepatic GSH concentrations were lower than control values for CMW after 7 and 15 days of exposure (34% decrease at both times), and this concentration was normalized by treatment with chitosan. SOD showed increased activity in liver after 15 and 30 days of exposure, 30% and 36%, respectively, and in fish exposed to RCM there was no change in this activity compared with the control group. Increased CAT activity in liver was observed during all experimental periods in fish exposed to CMW (46%, 50%, and 56% at 7, 15, and 30 days, respectively) compared with the control or treated-water groups. The highest increase in hepatic GST activity (106%) was observed only in fish exposed to CMW for 30 days. There was an increase in DNA damage in liver (50% at 7 and 15 days) and blood (79%, 77%, and 48% at 7, 15, and 30 days, respectively) after exposure to CMW. In contrast, the fish exposed to wastewater treated with chitosan microspheres exhibited DNA fragmentation indexes similar to the control group. The results obtained indicate the use of oxidative stress biomarkers as useful tools for the toxicity evaluation of coal mining effluents and also suggest that chitosan microspheres may be used as an alternative approach for remediation of coal mining wastewaters.

Assuntos

Quitosana/administração & dosagem , Minas de Carvão , Recuperação e Remediação Ambiental/métodos , Microesferas , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Animais , Biomarcadores , Catalase/fisiologia , Ciclídeos , Dano ao DNA , Glutationa/análise , Concentração de Íons de Hidrogênio , Peroxidação de Lipídeos , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo

RESUMO

The aim of the present study was to investigate the effects of daily intragastric administration of bullfrog oil (oleic, linoleic and palmitoleic acid-rich oil), corresponding to 0.4% of body weight for four weeks, on fatty acid composition and oxidative stress (lipid peroxidation and catalase activity) in mouse liver. The activities of aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT), biomarkers of tissue injury, were determined in liver homogenates and serum. The proportions of 18:2n-6, 20:4n-6, 20:5n-3, and 22:6n-3 (polyunsaturated fatty acids, from 37 to 60%) in the total fatty acid content were increased in the liver of the bullfrog oil-treated group (P < 0.05) compared to control. At the same time, a significant decrease in the relative abundance of 14:0, 16:0, and 18:0 (saturated fatty acids, from 49 to 25%) was observed. The hepatic content of thiobarbituric acid reactive substances (TBARS) was increased from 2.3 +/- 0.2 to 12.3 +/- 0.3 nmol TBA-MDA/mg protein and catalase activity was increased from 840 +/- 32 to 1110 +/- 45 micromol reduced H2O2 min-1 mg protein-1 in the treated group. Bullfrog oil administration increased AST and ALP activities in the liver (from 234.10 +/- 0.12 to 342.84 +/- 0.13 and 9.38 +/- 0.60 to 20.06 +/- 0.27 U/g, respectively) and in serum (from 95.41 +/- 6.13 to 120.32 +/- 3.15 and 234.75 +/- 11.5 to 254.41 +/- 2.73 U/l, respectively), suggesting that this treatment induced tissue damage. ALT activity was increased from 287.28 +/- 0.29 to 315.98 +/- 0.34 U/g in the liver but remained unchanged in serum, whereas the GGT activity was not affected by bullfrog oil treatment. Therefore, despite the interesting modulation of fatty acids by bullfrog oil, a possible therapeutic use requires care since some adverse effects were observed in liver.

Assuntos

Catalase/efeitos dos fármacos , Ácidos Graxos Insaturados/farmacologia , Ácidos Graxos/análise , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fosfatase Alcalina/análise , Animais , Biomarcadores/análise , Catalase/fisiologia , Fígado/metabolismo , Masculino , Camundongos , Rana catesbeiana , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Transaminases/análise , gama-Glutamiltransferase/análise

RESUMO

Catalase is an antioxidant enzyme that plays a very important role in the protection against oxidative damage by breaking down hydrogen peroxide. It is a very highly conserved enzyme that has been identified from numerous species including bacteria, fungi, plants and animals, but the information about catalase in crustaceans is very limited. A cDNA containing the complete coding sequence for catalase from the shrimp Penaeus (Litopenaeus) vannamei was sequenced and the mRNA was detected by RT-PCR in selected tissues. Catalase was detected in hepatopancreas crude extracts by Western blot analysis with anti-human catalase polyclonal antibodies. The nucleotide sequence is 1692 bp long, including a 72-bp 5'-UTR, a coding sequence of 1515 bp and a 104-bp 3'-UTR. The deduced amino acid sequence corresponds to 505 amino acids with high identity to invertebrate, vertebrate and even bacterial catalases and contains the catalytic residues His71, Asn144, and Tyr354. The predicted protein has a calculated molecular mass of 57 kDa; which coincides with the size of the subunit (approximately 55 kDa) and the tetrameric protein (approximately 230 kDa) detected in hepatopancreas extracts under native conditions. Catalase mRNA level was higher in hepatopancreas, followed by gills and was not detected in muscle.

Assuntos

Catalase/fisiologia , Regiões 3' não Traduzidas , Regiões 5' não Traduzidas , Sequência de Aminoácidos , Animais , Antioxidantes/química , Sequência de Bases , Western Blotting , Catalase/metabolismo , Clonagem Molecular , DNA Complementar/metabolismo , Eletroforese em Gel de Poliacrilamida , Hepatopâncreas/metabolismo , Humanos , Dados de Sequência Molecular , Penaeidae , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos

RESUMO

Tardive dyskinesia, the most serious iatrogenic movement disorder, has been tentatively associated with nigrostriatal dopaminergic supersensitivity and with oxidative stress. It is also suggested that long-term neuroleptic treatment does not cause oral dyskinesia (OD), but interacts with some substrate of brain aging, resulting in the premature emergence of OD, that can occur spontaneously with aging. In order to investigate a possible role of nigrostriatal dopaminergic supersensitivity and of oxidative stress in aging- and reserpine-induced OD, the stereotyped behavior induced by dopaminergic agonists, a functional index of dopaminergic striatal activity, as well as the striatal antioxidant enzymes glutathione peroxidase and catalase were assessed. We demonstrate that, opposite to normotensive Wistar rats (NWR), spontaneously hypertensive rats (SHR) do not develop aging- or reserpine-OD. There were no differences between NWR and SHR in stereotyped behavior or in striatal glutathione peroxidase activity. Adult and old SHR presented higher striatal catalase activity relative to NWR, and aging increased it only in SHR. The catalase inhibitor aminotriazole reverted the absence of aging- and reserpine-induced OD in SHR. Our results suggest an important role of striatal catalase in the development of reserpine- and aging-induced OD.

Assuntos

Envelhecimento/fisiologia , Catalase/fisiologia , Discinesia Induzida por Medicamentos/fisiopatologia , Neostriado/enzimologia , Reserpina , Amitrol (Herbicida)/farmacologia , Animais , Catalase/antagonistas & inibidores , Agonistas de Dopamina/farmacologia , Inibidores Enzimáticos/farmacologia , Glutationa Peroxidase/antagonistas & inibidores , Glutationa Peroxidase/metabolismo , Masculino , Neostriado/fisiologia , Estresse Oxidativo/fisiologia , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Comportamento Estereotipado/efeitos dos fármacos

RESUMO

Las formulaciones disponibles actualmente para uso dermatológico, basadas en sustancias antioxidantes tales como vitaminas C y E, entre otras, abundan con promesas de revertir el envejecimiento cutáneo. En el presente trabajo se realiza una revisión de los sistemas antioxidantes cutáneos, de la relación entre envejecimiento y daño oxidativo, así como de la evidencia disponible en cuanto al tratamiento con antioxidantes. La intención de este artículo es que el dermatólogo comprenda las bases fisiológicas de acción de los antioxidantes, para poder juzgar su utilidad con una mirada crítica (AU)

Assuntos

Humanos , Animais , Envelhecimento da Pele , Antioxidantes/fisiologia , Ácido Ascórbico/uso terapêutico , Vitamina E/uso terapêutico , Pele/efeitos da radiação , Espécies Reativas de Oxigênio , Raios Ultravioleta/efeitos adversos , Antioxidantes/uso terapêutico , Antioxidantes/efeitos da radiação , Ácido Ascórbico/farmacologia , Ácido Ascórbico/fisiologia , Vitamina E/farmacologia , Vitamina E/fisiologia , Pele/efeitos dos fármacos , Fenômenos Fisiológicos da Pele , Superóxido Dismutase/fisiologia , Superóxido Dismutase/efeitos da radiação , Catalase/fisiologia , Catalase/efeitos da radiação , Peroxidase/fisiologia , Peroxidase/efeitos da radiação , Glutationa Peroxidase/fisiologia , Glutationa Peroxidase/efeitos da radiação , Glutationa Redutase/fisiologia , Glutationa Redutase/efeitos da radiação , Glutationa Transferase/fisiologia , Glutationa Transferase/efeitos da radiação , beta Caroteno/fisiologia , beta Caroteno/efeitos da radiação , Ubiquinona/fisiologia , Ubiquinona/efeitos da radiação , Ozônio/efeitos adversos , Administração Tópica , Cosméticos , Ensaios Clínicos como Assunto , Interleucinas/efeitos da radiação , Luz Solar/efeitos adversos

RESUMO

En condiciones fisiológicas las células aeróbicas producen cantidades de Especies Reactivas de Oxígeno. La supervivencia celular depende del balance entre los procesos oxidativos y las defensas antioxidantes. Esta interacción determina si la célula se encuentra en estrés oxidativo o no. Recientes estudios sugieren que una reducida capacidad en el metabolismo oxidativo así como estados proinflamatorios contribuyen a cambios neurodegenerativos relacionados con la edad en los humanos. Por tal motivo en el presente estudio nosotros comparamos los niveles séricos de la actividad de la superóxido dismutasa (SOD), Catalasa (CAT) y también los niveles de malonildialdehido (MDA) y el factor de necrosis tumoral a (TNFa) en primates no humanos jóvenes y viejos. Nuestros resultados sugieren relación entre las alteraciones del metabolismo oxidativo con los cambios neurodegenerativos que ocurren en los monos.

Assuntos

Animais , Envelhecimento/metabolismo , Sobrevivência Celular/fisiologia , Haplorrinos/metabolismo , Superóxido Dismutase/fisiologia , Catalase/fisiologia , Senescência Celular/fisiologia , Estresse Oxidativo/fisiologia