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Background and aims: Mycobacterium tuberculosis (Mtb), the main causative agent of human tuberculosis (TB), remains as a serious public health problem. The innate immune response following Mtb infection plays a crucial role in preventing the onset of active TB and limiting its spread. Since phagocytes-derived reactive oxygen/nitrogen species (ROS/RNS) during the oxidative burst can fight Mtb, we hypothesized that the use of antioxidants could increase the host's susceptibility to Mtb/TB. In that way, we investigated the effects of the nitroxide Tempol, an antioxidant with superoxide dismutase-like activity, on the response of neutrophils against Mtb. Methods: Human blood-derived neutrophils were isolated from healthy volunteers and incubated with Mtb (H37Ra) at different multiplicities of infection (MOIs), in the absence or presence of Tempol. The levels of ROS in neutrophils were evaluated using the cytochrome C reduction assay (extracellular O2•-) and luminol-(total intracellular and extracellular ROS) and isoluminol-(extracellular ROS) amplified chemiluminescence assay. The killing assay (two-step protocol) checked the mycobactericidal capacity of neutrophils, as calculated the phagocytosis (Kp) and intracellular killing (Kk) rates. Results: The levels of ROS and killing capacity in Mtb-stimulated neutrophils were significantly decreased by 450 μM Tempol (p < 0.05). Interestingly, Tempol decreased the kk of neutrophils, but did not affect their kp, demonstrating that a putative diminution in ROS levels, ultimately, affected the intracellular killing of Mtb. Conclusion: This study provides insights regarding the role of antioxidants on the neutrophil response toward Mtb, so that our findings deserve to be considered regarding further studies and clinical implications. [ABSTRACT FROM AUTHOR]

This study identified physiological and biochemical changes in 'Fuyu' persimmon buds during dormancy. Branches were collected between March and August 2015. Dormancy was evaluated by biological testing of isolated node cuttings at 25 °C and a photoperiod of 16 h. The variables analyzed were water content; reducing sugar content; respiratory activity; activity of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (POD) and polyphenol oxidase (PPO) enzymes; hydrogen peroxide content (H2O2) and lipid peroxidation. At the end of March 2015, the plants were already dormant, and the leaves and fruits present indicated a paradormancy effect. Induction of endodormancy may have occurred in June 2015, when chilling hours (CH) below 7.2 °C and higher CH below 12 °C began to accumulate, which coincided with the period in which there was a decrease in water content and respiratory activity, an increase in reducing sugars, a decrease in SOD, CAT, APX and PPO and an increase in H2O2. After an accumulation of 553 CH below 12 °C, the budburst capacity increased, and the buds presented increased water content, decreased reducing sugars content, increased respiratory activity, low activity in SOD, CAT, APX and POD and high levels of H2O2. [ABSTRACT FROM AUTHOR]

Aging is a natural process characterized by a progressive decline in the physiological integrity and regenerative capacity of the body. In pathological aging, decline is accelerated and is often associated with a systemic pro-inflammatory status. Reactive species of oxygen and other free radicals are produced naturally in metabolism and during inflammation, but in excess they cause oxidative stress and tissue damage. With aging, the accumulation of oxidative changes alters the structure and function of biomolecules and cellular components such as membranes and organelles, making the organism globally more susceptible to stressors and pathogens. This review will focus on the contribution of oxidative stress to the different molecular mechanisms of aging. Aging is the main risk factor for the development of chronic--degenerative diseases. Therefore, the understanding of its molecular mechanisms will contribute to the development of new therapeutic strategies aimed at increasing the quality of life in aging. [ABSTRACT FROM AUTHOR]

Post-harvest storage of fleshy fruit is a strategy used for improving seed quality. The aim of this study was to evaluate post-harvest storage of the fruit of C. baccatum var. baccatum (cumari pepper) and relate it to antioxidant enzyme activity and seed physiological potential. Red-colored fruit (65 days after anthesis) was gathered and stored at 20 °C for 0, 5, 10, 15, and 20 days. The seeds were removed and evaluated for moisture content, physiological quality, antioxidant enzyme activity, and protein content. The means were fitted to regression equations and then passed through multivariate analysis (PCA). Seed moisture and 100-seed weight decreased through post- harvest storage. The 5- and 10-days storage periods led to an increase in the germination. Electrical conductivity was greater for the 0- and 20-day storage periods. Dry matter and protein increased in the 5- and 10-days. Enzymes exhibited reductions of activity comparing 0 and 20 days. The post-harvest storage of C. baccatum fruit for 5 and 10 days improves seed physiological potential and is related to physiological maturity. The incomplete maturation of cumari seeds obtained from unstored fruit (0 days) is related to greater enzyme activity, greater oxidative stress, and low germination and vigor. The lack of post-harvest storage of fruit and storage of fruit for longer than 10 days contributes to a lower physiological potential of cumari pepper seeds. [ABSTRACT FROM AUTHOR]

Drought and temperature will be increased by climatic change. Many crops will be affected, for example, "cacao" Theobroma cacao L. (Malvaceae). Both water stress and temperature increase can cause physiological and biochemical damages, which diminish the productivity of this species. Moreover, there are few studies about the effect of these abiotic stresses on cacao. Therefore, it is necessary to explore the genetic material that can be used in conditions of climate change. In this sense, this review tries to relate the existing works and to draw strategies on the importance of this crop in the studies that involve climate change. [ABSTRACT FROM AUTHOR]

Brown eye spot (BE) caused by Cercospora coffeicola is the main disease of coffee crop. A variation in symptoms of BE has been reported in the field, raising suspicion of occurrence of new species. However, information about coffee-C. coffeicola interaction is still limited. This research aimed to determine the difference between antioxidant metabolism of coffee plants cultivar Mundo Novo inoculated with a strain isolated from a common BE lesion (CML 2984) and a strain isolated from a black BE lesion (CML 2985). The enzyme activity of peroxidase (POX), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) and phenylalanine ammonia lyase (PAL) were determined. Activities of POX, APX, and PAL increased in plants inoculated with both strains compared to noninoculated plants at 12 and 24 hours post inoculation (hpi). CAT activity increased in inoculated plants with black BE strain at 24 hpi and both strains at 48 hpi. The SOD activity only increased in inoculated plants with both strains at 48 hpi. These results show that an elevated antioxidant response was observed when the plants were challenged with both strains of C. coffeicola. Both strains produced lesions of the common type, suggesting that other factors lead to the development of black BE lesion type under field conditions and further investigation is needed. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the neuroprotective effect of ω-conotoxin MVIIA (MVIIA) intralesional application in rats submitted to spinal cord injury. Male Wistar rats, weighing 300g±23.4, were distributed in five groups: negative control (SHAM), placebo (PLA), 5μM MVIIA, 10μM MVIIA and 20μM MVIIA MVIIA. After laminectomy of the 12th thoracic vertebra (SHAM), the PLA, 5μM MVIIA, 10μM MVIIA and 20μM MVIIA groups were subjected to acute compressive spinal cord trauma for five minutes, and then five minutes later, the animals received specific treatment in a standard total volume of 2μL, by intralesional route, using sterile PBS as placebo. Locomotor activity was assayed using Basso Beattie Bresnahan (BBB) scale to show the patterning of SCI. With 48 hours of injury, the animals were euthanized, the liquor sample was collected in atlantooccipital space, and also the spinal segment, including the epicenter and caudal region to injury. Assays were performed for mitochondrial viability, serum glutamate, production of reactive oxygen species (ROS) and lipid peroxidation (LP) were performed. The study design was randomized and the data submitted to ANOVA and comparison of means by SNK test, and data from BBB scale were evaluated using Kruskal-Wallis test (P<0.05). There was no significant difference between groups in BBB scores. The MVIIA did not promote decrease in the levels of glutamate, ROS, LP, and did not preserve the mitochondria in the intralesional application five minutes after spinal cord injury in rats. [ABSTRACT FROM AUTHOR]

This work aimed to compare two grapevine varieties grown in Portugal, Syrah and Touriga Nacional, in terms of their physiological and biochemical behavior in response to a cycle of severe water stress followed by rehydration. Vines were subjected to either continuous watering (FI) or not watered for 21 days and rehydrated after leaf water potential at predawn reach -1.1 MPa (NI). Observations took place at four stages: i) immediately before water withdrawal (day 0), ii) Maximum stress (day 21), iii) two days after rehydration (day 23) and iv) six days after rehydration (day 27). We measured leaf water potential at pre-dawn (Ψpd) and at midday (Ψmd), stomatal conductance to water vapor (gs), net photosynthesis (An), transpiration (E), the sub-stomatal CO2 concentration (ci) and chlorophyll a fluorescence. The contents of total chlorophyll content and hydrogen peroxide (H2O2) in leaves were determined as well. All parameters were negatively affected by water stress, except basal fluorescence (Fo). The recovery capacity in terms of water potential and leaf gas exchange was similar in both varieties but it proved incomplete, in particular for net photosynthesis. The variety ‘Touriga Nacional’ showed higher degradation of chlorophyll and higher levels of H2O2 in leaves than the ‘Syrah’ variety, which may explain the high susceptibility of Touriga to leaf senescence and leaf drop under water stress conditions in the field. [ABSTRACT FROM AUTHOR]

The scarce fertility of the cryopreserved equine sperm has significantly limited its use in reproductive biotechnology. Oxidative stress is one of the facts that are related the most to this phenomenon, due to the increase in the levels of species that react to oxygen in the sperm as a result of the thermal shock, the toxicity of cryoprotectors and the alteration in the disposal and the functionality of the endogenous antioxidants during cryopreservation. This revision article analyzes the effect of oxidative stress on the cryopreserved equine sperm's fertility [ABSTRACT FROM AUTHOR]

The scarce fertility of the cryopreserved equine sperm has significantly limited its use in reproductive biotechnology. Oxidative stress is one of the facts that are related the most to this phenomenon, due to the increase in the levels of species that react to oxygen in the sperm as a result of the thermal shock, the toxicity of cryoprotectors and the alteration in the disposal and the functionality of the endogenous antioxidants during cryopreservation. This revision article analyzes the effect of oxidative stress on the cryopreserved equine sperm's fertility [ABSTRACT FROM AUTHOR]

Introdução: Os fibroblastos compõem as principais células da pele, sendo responsáveis pelo processo de cicatrização de lesões. O estresse oxidativo, causado pela produção excessiva de Espécies Reativas de Oxigênio (EROs), é responsável por agravar o processo de envelhecimento celular, prejudicando as funções de proliferação e cicatrização dos fibroblastos, contribuindo para o aparecimento de lesões teciduais. Desta forma, torna-se relevante a busca por compostos naturais que possam auxiliar no reparo destas lesões, como é o caso do barbatimão, planta do Cerrado, utilizada pela medicina tradicional como cicatrizante devido à sua potencial atividade antioxidante. Objetivo: Avaliar in vitro o efeito do barbatimão em marcadores de estresse oxidativo de fibroblastos humanos senescentes. Métodos: Células da linhagem de fibroblastos humanos (HFF-1) foram cultivadas em condições controladas até atingirem morfologia senescente via observação por microscopia confocal. As células senescentes foram expostas ao extrato de barbatimão nas concentrações de 0,49mg/mL e 0,99mg/mL. Após 72 horas de exposição, foram analisados espectrofotometricamente os níveis de carbonilação de proteínas e lipoperoxidação. Resultados: O barbatimão mostrou-se eficiente em reduzir os níveis dos marcadores oxidativos em ambas as concentrações utilizadas, diminuindo tanto o dano às proteínas como aos lipídeos. Conclusões: Apesar das limitações metodológicas inerentes aos estudos in vitro, nossos resultados indicam que o barbatimão desempenha atividade positiva no combate ao estresse oxidativo, podendo ser um poderoso aliado na prevenção do aparecimento de lesões por pressão, um grande problema de saúde pública no Brasil, principalmente entre idosos acamados. Entretanto, mais estudos precisam ser realizados para confirmação desta hipótese. [ABSTRACT FROM AUTHOR]

Introdução: O envelhecimento é um fator de risco para o desenvolvimento de doenças cardiovasculares, sendo a aterosclerose um exemplo destas patologias, a qual se caracteriza pelo acumulo de gordura, especialmente lipoproteínas de baixa densidade (LDL), nas artérias. Sabendo que o acumulo e a oxidação do LDL por espécies reativas de oxigênio (EROs) fazem parte do mecanismo de iniciação e progressão das placas de ateromas, e que fragmentos da placa podem se desprender, ocluindo as artérias e gerando falta de oxigênio e morte de tecidos, como ocorre no infarto do miocárdio, que é a principal causa de morte no mundo, se torna necessária a busca por alimentos que possam diminuir a oxidação do LDL. O cubiu (Solanum sessiliflorum), fruto amazônico conhecido por seu forte poder antioxidante, poderia ser utilizado no combate às EROs que oxidam o LDL. Objetivo: Investigar o efeito do cubiu sobre a oxidação do colesterol LDL. Métodos: Preparação do extrato hidroalcóolico do cubiu proveniente de Maués-AM. Sangue foi coletado e amostras de plasma contendo LDL foram incubadas com um agente oxidante e com o extrato hidroalcólico nas concentrações de 3 a 300 µg / mL. Resultados: Diferentes concentrações de cubiu foram capazes de controlar processos de oxidação de LDL no plasma in vitro. Conclusão: Nossos resultados sugerem que o extrato de cubiu tem potencial ação protetora frente a oxidação do LDL, indicando capacidade de prevenção da formação de ateromas. Mais estudos precisam ser realizados para a confirmação desta hipótese e possível indicação do cubiu como suplemento alimentar. [ABSTRACT FROM AUTHOR]