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Different concentrations of Ni are found in agricultural soil released from various environmental sources. The responses of plants grown in such soil-substratum vary accordingly depending upon the concentration of metal present and plant species. To assess the toxic effects of Ni and extent of plant defensive strategies, increasing Ni doses (50, 100, and 150 mg kg-1) were used in sandy-loam soil-substratum at pH 7.9 to evaluate the performance of Vigna species ( V. cylindrica [L.] Skeels, V. mungo [L.] Hepper, and V. radiata [L.] R. Wilczek). The experiment was conducted in a complete randomized design. Nickel stress was induced by adding various concentrations of Ni chloride in soil substratum. Malondialdehyde (MDA) and antioxidant levels were determined in roots and leaves. Escalating levels of Ni in soil resulted in an affirmative relationship between MDA with that of antioxidants. A dose-dependent increase in the activity of Superoxide Dismutases (SOD), Catalase (CAT), and peroxidases (POD) suggested the existence of a sequence response of these enzymes to scavenge oxidative stress in the roots. However, inadequate production of SOD and CAT appeared to be compensated by the enhanced activity of POD, which acted as potent quencher to reactive oxygen species (ROS) in leaves. At the most elevated Ni dose, SOD, CAT and POD activities were insufficient to counteract ROS generated that led to membrane damage manifested by elevated MDA levels. Nevertheless, SOD and CAT alleviated Ni toxicity in roots while SOD, CAT and POD acted in a concurrent manner to protect leaves from oxidative damage in V. cylindrica. The study clearly indicated a Ni dependent antioxidant enzymes defense system in V. cylindrica.

Introduction. To avoid conceptual ambiguity, endurance training in this study is referred to as MICT, which reflects sustained efforts at moderate intensity (zone 2 of Seiler’s triphasic model). By contrast, HIIT is classified as vigorous intermittent exercise (zone 3). This differentiation is essential for comparing the physiological adaptations of both modalities (Seiler, 2010). Oxidative stress, arising from an imbalance between reactive oxygen species (ROS) production and antioxidant capacity, can cause cellular damage and contribute to chronic diseases. Biomarkers such as malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) are used to assess this imbalance. Physical exercise, particularly high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), modulates redox homeostasis, but their comparative effects remain underexplored. Objective. To compare the effects of a HIIT protocol versus an moderate-intensity continuous training (MICT) protocol on oxidative stress markers (MDA, CAT, SOD) in healthy athletes, enhancing understanding of exercise-induced physiological adaptations. Methodology. Twenty healthy male athletes (aged 18–35 years) were randomized into two groups (MICT, n=10; HIIT, n=10) following a 4-week training protocol (3 sessions/week, 60–80% VO₂max). MDA, CAT, and SOD levels were measured via colorimetry before and after exercise at the start and end of the program. Repeated-measures ANOVA assessed the effects of exercise, training program, and their interactions, with a significance threshold of p<0.05. Findings. Both training modalities increased CAT activity (MICT: +5.4% at rest, +10.0% post-exercise; HIIT: +6.4% at rest, +11.0% post-exercise) with no inter-group differences. SOD levels increased in the MICT group at rest (+5.3%) and post-exercise (+6.0%), but only post-exercise in the HIIT group (+8.4%). MDA levels decreased at rest in both groups (MICT: -15.2%; HIIT: -17.3%) and post-exercise in the HIIT group (-13.0%), but not in the MICT group post-exercise. Introducción. Para evitar ambigüedades conceptuales, en este estudio el entrenamiento de resistencia se denomina MICT, lo que refleja esfuerzos sostenidos de intensidad moderada (zona 2 del modelo trifásico de Seiler). En cambio, el HIIT se clasifica como ejercicio intermitente vigoroso (zona 3). Esta diferenciación es esencial para comparar las adaptaciones fisiológicas de ambas modalidades (Seiler, 2010). El estrés oxidativo, que surge de un desequilibrio entre la producción de especies reactivas de oxígeno (ROS) y la capacidad antioxidante, puede causar daño celular y contribuir a enfermedades crónicas. Se utilizan biomarcadores como el malondialdehído (MDA), la catalasa (CAT) y la superóxido dismutasa (SOD) para evaluar este desequilibrio. El ejercicio físico, particularmente el entrenamiento interválico de alta intensidad (HIIT) y el entrenamiento continuo de intensidad moderada (MICT), modula la homeostasis redox, pero sus efectos comparativos siguen poco explorados. Objetivo. Comparar los efectos de un protocolo de HIIT frente a un protocolo de entrenamiento continuo de intensidad moderada (MICT) sobre los marcadores de estrés oxidativo (MDA, CAT, SOD) en atletas sanos, para mejorar la comprensión de las adaptaciones fisiológicas inducidas por el ejercicio. Metodología. Veinte atletas varones sanos (18–35 años) fueron asignados aleatoriamente a dos grupos (MICT, n=10; HIIT, n=10) y siguieron un protocolo de entrenamiento de 4 semanas (3 sesiones/semana, 60–80 % del VO₂máx). Los niveles de MDA, CAT y SOD se midieron mediante colorimetría antes y después del ejercicio al inicio y al final del programa. Se utilizó un ANOVA de medidas repetidas para evaluar los efectos del ejercicio, del programa de entrenamiento y sus interacciones, con un nivel de significación de p<0,05. Resultados. Ambas modalidades de entrenamiento aumentaron la actividad de CAT (MICT: +5,4 % en reposo, +10,0 % post-ejercicio; HIIT: +6,4 % en reposo, +11,0 % post-ejercicio) sin diferencias intergrupales. Los niveles de SOD aumentaron en el grupo MICT en reposo (+5,3 %) y post-ejercicio (+6,0 %), pero solo post-ejercicio en el grupo HIIT (+8,4 %). Los niveles de MDA disminuyeron en reposo en ambos grupos (MICT: -15,2 %; HIIT: -17,3 %) y post-ejercicio en el grupo HIIT (-13,0 %), pero no en el grupo MICT post-ejercicio. Introdução. Para evitar ambiguidades conceptuais, neste estúdio o treino de resistência é designado por MICT, que reflete esforços sustentados de intensidade moderada (zona 2 do modelo trifásico de Seiler). Em mudança, o HIIT é classificado como exercício intermitente vigoroso (zona 3). Esta diferenciação é essencial para comparar as adaptações fisiológicas de ambas as modalidades (Seiler, 2010). O stress oxidativo, que surge do desequilíbrio entre a produção de espécies reativas de oxigénio (ROS) e a capacidade antioxidante, pode causar danos celulares e contribuir para doenças crónicas. São utilizados biomarcadores como o malondialdeído (MDA), a catalasa (CAT) e a superóxido dismutase (SOD) para avaliar este desequilíbrio. O exercício físico, especialmente o treino interválico de alta intensidade (HIIT) e o treino contínuo de intensidade moderada (MICT), modula a homeostasia redox, mas os seus efeitos comparativos são pouco explorados. Objetivo. Comparar os efeitos de um protocolo de HIIT face a um protocolo de treino contínuo de intensidade moderada (MICT) nos marcadores de stress oxidativo (MDA, CAT, SOD) em atletas saudáveis, para melhorar a compreensão das adaptações físicas induzidas pelo exercício. Metodologia. Veinte atletas varones sans (18–35 anos) foram aleatoriamente designados para dois grupos (MICT, n=10; HIIT, n=10) e seguiram um protocolo de treino de 4 semanas (3 sessões/semana, 60–80% do VO₂máx). Os níveis de MDA, CAT e SOD são medidos através de colorimetria antes e depois do exercício no início e no final do programa. Foi utilizada uma ANOVA de medidas repetidas para avaliar os efeitos do exercício, do programa de treino e das suas interações, com um nível de significância de p<0,05. Resultados. Ambas as modalidades de treino aumentaram a atividade da CAT (MICT: +5,4% em repouso, +10,0% pós-exercício; HIIT: +6,4% em repouso, +11,0% pós-exercício) sem diferenças intergrupais. Os níveis de SOD aumentaram no grupo MICT em repouso (+5,3%) e pós-exercício (+6,0%), mas apenas pós-exercício no grupo HIIT (+8,4%). Os níveis de MDA diminuíram em repouso em ambos os grupos (MICT: -15,2%; HIIT: -17,3%) e pós-ejercicio no grupo HIIT (-13,0%), mas não no grupo MICT pós-ejercicio.

The study examined the effect of refrigerated storage on antioxidant activities, lipid and protein oxidation, fatty acids (FAs), drip loss and color of semimembranosus (SM) muscle from goats. Samples of SM were obtained from carcasses of 15 Boer bucks (7 months old; body weight, 32.18 ± 0.81 kg) subjected to an 8 d storage at 4°C. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities were stable while carotenoid, tocopherol, water holding capacity and redness declCned (P < 0.05) as storage progressed. Carbonyl content increased from 1.85 to 4.73 nmol/mg protein while thiol content reduced from 54.22 to 42.82 nmol/mg protein. The TBARS value increased from 0.2 to 0.8 mg MDA/kg. SDS-PAGE expression of myosin heavy chain (MHC) decreased (P < 0.05) from 72.45 to 49.82 density/mm 2 while actin reduced (P > 0.05) from 14.00 to 13.08 density/mm 2 . The concentrations of n-3 and n-6 FA decreased while the saturated FA increased over storage. Correlations (P < 0.05) were found between antioxidant vitamins and quality indicators of chevon.

In this study were evaluated the effects of the chronic consumption of agraz (Vaccinium meridionale) on antioxidant status and oxidative stress markers in 40 women with metabolic syndrome (MetS) (47.2 ± 9.4 years) through a double-blind, crossover design study, in which participants consumed daily agraz or placebo during 4 weeks, separated by a 4-wk washout period. At the end of each intervention period, endogenous antioxidant enzymes activity, serum total antioxidant capacity (TAC) (ferric reducing ability of plasma [FRAP]; Oxygen Radical Absorbance Capacity [ORAC] and 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) [ABTS]), and oxidative stress markers (Oxo-2ʹ-deoxyguanosine (8-OHdG) and F2-isoprostane) were determined. Women who increased endogenous antioxidant enzymes activity and serum TAC after agraz consumption, compared to placebo, significantly reduced oxidative stress markers, total cholesterol, LDL-cholesterol (LDL-c) levels, and waist circumference, demonstrating beneficial effects in the group of women in whom antioxidant parameters increased after agraz consumption, evidencing an individual variability in response to the beverage consumed.

Fungi, with all their biological and enzymatic qualities, could have great potential being implemented in industrial processes. In this study, filamentous fungi from Sonsón-Antioquia region were isolated and characterized. A morphological characterization was carried out using taxonomic keys and additionally a biochemical characterization qualitatively evaluated the amylolytic, cellulolytic, lipolytic, proteolytic, catalase, peroxidase, and laccase capacity of the strains. Furthermore, isolated fungi were molecularly identified using the LSU region of the rDNA (28S). Among the strains identified, Trichoderma sp., Penicillium sp., Mucor sp. Aspergillus sp. and Lecythophora sp. genera were found and it was observed that the analyzed fungi present at least one of the seven enzymatic activities evaluated and some genera such as Trichoderma sp. and Aspergillus sp. present even six of them. Therefore, the isolated strains show desirable characteristics in food, paper, cosmetic, and textile industries, and in areas such as bioremediation and biological control.

Different concentrations of Ni are found in agricultural soil released from various environmental sources. The responses of plants grown in such soil-substratum vary accordingly depending upon the concentration of metal present and plant species. To assess the toxic effects of Ni and extent of plant defensive strategies, increasing Ni doses (50, 100, and 150 mg [kg.sup.-1]) were used in sandy-loam soil-substratum at pH 7.9 to evaluate the performance of Vigna species (V cylindrica [L.] Skeels, V. mungo [L.] Hepper, and V radiata [L.] R. Wilczek). The experiment was conducted in a complete randomized design. Nickel stress was induced by adding various concentrations of Ni chloride in soil substratum. Malondialdehyde (MDA) and antioxidant levels were determined in roots and leaves. Escalating levels of Ni in soil resulted in an affirmative relationship between MDA with that of antioxidants. A dose-dependent increase in the activity of Superoxide Dismutases (SOD), Catalase (CAT), and peroxidases (POD) suggested the existence of a sequence response of these enzymes to scavenge oxidative stress in the roots. However, inadequate production of SOD and CAT appeared to be compensated by the enhanced activity of POD, which acted as potent quencher to reactive oxygen species (ROS) in leaves. At the most elevated Ni dose, SOD, CAT and POD activities were insufficient to counteract ROS generated that led to membrane damage manifested by elevated MDA levels. Nevertheless, SOD and CAT alleviated Ni toxicity in roots while SOD, CAT and POD acted in a concurrent manner to protect leaves from oxidative damage in V. cylindrica. The study clearly indicated a Ni dependent antioxidant enzymes defense system in V. cylindrica.

Spontaneous necrotic lesions were found in a lesion mimic mutant brown leaf spot 2 (bl2) without pathogenic infection. Small spots in the seedlings appeared at the four leaves stage and gradually grew into a large round and black area with a gray center on the leaf surfaces. Lower growth habit and lower agronomic trait values with reduced stature, tiller, and panicle number, as well as lower yield potential were noted in the mutants relative to the trait values of the wild-type plants. Microscopic analysis revealed that mesophyll chloroplast was severely damaged or absent in the spotted area of the mutant leaves. Total chlorophyll content, hydrogen peroxide level, and catalase activity were increased at up to 45 days after germination and were dropped at 60 d in the mutant leaves. However, the total protein contents were reduced slightly with a growth period of up to 45 days and were increased at 60 days after germination. A gradual increment of the total ascorbic acid contents in the mutants were observed with advanced plant age, but increased until 45 days and dropped comparatively at 60 days in the wild-type leaves. Increased gene transcriptions of OsPDI and OsGPX1 were noted in the spotted leaves as compared to the non-spotted leaves of the mutant and wild-type leaves, whereas transcripts of OsTPX were transcribed at lower levels in the spotted leaves as compared to the non-spotted leaves. The genetic nature of the bl2 mutant indicated that the F₁ plants evidenced the wild-type phenotype and that bl2 was governed by a single recessive gene.

Reactive oxygen species (ROS) play a prominent role in early and later stages of the plant pathogenesis response, putatively acting as both cellular signaling molecules and direct antipathogen agents. A single-cell assay, based on the fluorescent probe dichlorofluorescein, was used to scrutinize the generation and movement of ROS in tobacco epidermal tissue. ROS, generated within cells, quickly moved apoplastically as H2O2 into neighboring cells. Two classes of rapidly elicited intracellular ROS, originating from distinct sources, were distinguished. Cryptogein, the fungal elicitor from Phytophthora cryptogea, induced ROS from a flavin-containing oxidase source. ROS accumulation could be inhibited by a number of pharmacological agents, suggesting induction through an active signal transduction pathway. The insensitivity of the increase in ROS to the external addition of enzymes that dissipate ROS suggests that this exidative increase is primarily intracellular. In contrast, amines and polyamines, compounds that form during wounding and pathogenesis, induced ROS at an apoplastic site from peroxidase- or amine oxidase-type enzyme(s). Salicylic acid, a putative inhibitor of cellular catalases and peroxidases, did not induce cellular ROS, as messured by dichlorofluorescein fluorescence. The physiological relevance of ROS-generated signals was indicated by the rapid alteration of the epidermal cell glutathione pool and the cellular redox state. In addition, induction of ROS by all elicitors was correlated with subsequent cell death

Earlier studies with Arabidopsis thaliana exposed to ultraviolet B (UV-B) and ozone (O3) have indicated the differential responses of superoxide dismutase and glutathione reductase. In this study, we have investigated whether A. thaliana genotype Landsberg erecta and its flavonoid-deficient mutant transparent testa (tt5) is capable of metabolizing UV-B- and O3-induced activated oxygen species by invoking similar antioxidant enzymes. UV-B exposure preferentially enhanced guaiacol-peroxidases, ascorbate peroxidase, and peroxidases specific to coniferyl alcohol and modified the substrate affinity of ascorbate peroxidase. O3 exposure enhanced superoxide dismutase, peroxidases, glutathione reductase, and ascorbate peroxidase to a similar degree and modified the substrate affinity of both glutathione reductase and ascorbate peroxidase. Both UV-B and O3 exposure enhanced similar Cu,Zn-superoxide dismutase isoforms. New isoforms of peroxidases and ascorbate peroxidase were synthesized in tt5 plants irradiated with UV-B. UV-B radiation, in contrast to O3, enhanced the activated oxygen species by increasing membrane-localized NADPH-oxidase activity and decreasing catalase activities. These results collectively suggest that (a) UV-B exposure preferentially induces peroxidase-related enzymes, whereas O3 exposure invokes the enzymes of superoxide dismutase/ascorbate-glutathione cycle, and (b) in contrast to O3, UV-B exposure generated activated oxygen species by increasing NADPH-oxidase activity

We investigated how salicylic acid (SA) enhances H2O2 and the relative significance of SA-enhanced H2O2 in Arabidopsis thaliana. SA treatments enhanced H2O2 production, lipid peroxidation, and oxidative damage to proteins, and resulted in the formation of chlorophyll and carotene isomers. SA-enhanced H2O2 levels were related to increased activities of Cu,Zn-superoxide dismutase and were independent of changes in catalase and ascorbate peroxidase activities. Prolonging SA treatments inactivated catalase and ascorbate peroxidase and resulted in phytotoxic symptoms, suggesting that inactivation of H2O2-degrading enzymes serves as an indicator of hypersensitive cell death. Treatment of leaves with H2O2 alone failed to invoke SA-mediated events. Although leaves treated with H2O2 accumulated in vivo H2O2 by 2-fold compared with leaves treated with SA, the damage to membranes and proteins was significantly less, indicating that SA can cause greater damage than H2O2. However, pretreatment of leaves with dimethylthiourea, a trap for H2O2, reduced SA-induced lipid peroxidation, indicating that SA requires H2O2 to initiate oxidative damage. The relative significance of the interaction among SA, H2O2 and H2O2-metabolizing enzymes with oxidative damage and cell death is discussed