Publications by authors named "Miriam M Chaves"

During aging, in addition to increased oxidative stress, inflammation also occurs. A chronic and low-grade inflammation - called "inflammaging" - develops, which contributes to the etiology of diseases related to aging. Resveratrol (Resv.

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Introduction: One of the markers of aging is oxidative stress, a condition characterized by an increase in free radicals concomitant with a reduction in antioxidant defenses. Within this, resveratrol is a compound that has been shown to act as a potent antioxidant. However, few studies highlight the cellular signaling pathways that are activated or inhibited during aging and that are responsible for this biological effect.

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One of the theories related to aging is the increase in oxidative stress. Given this, the objective of the study is to evaluate the cellular mechanisms responsible for the resveratrol antioxidant effect on leukocytes from donors aged between 20 and 80 years old. For this, leukocytes from donors of three age groups (20-39, 40-59 and 60-80) were isolated.

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In the elderly, there is an increase in oxidative and inflammatory activity. Resveratrol (RSV) is a polyphenol that has several proven biological activities, such as antioxidant and anti-inflammatory. Thus, the aim of our study was to verify the possible antioxidant and anti-inflammatory effects of RSV on human mononuclear cells (PBMCs) from donors aged between 40 and 59 and 60-80 years old.

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Currently, the important role of oxidative stress in the aging process and in neurodegenerative diseases has been highlighted, suggesting the beneficial effect of antioxidants as adjuvant therapy. Resveratrol (RSV) is a polyphenolic compound used in the clinic and has been shown as an antioxidant and anti-inflammatory. Therefore, the objective was to verify neuroprotective and modulating effects of RSV on N2-A cells, pre or post inserted into an oxidative stress environment.

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Background: One of the most studied theories about aging comes from the accumulation of free radical generation, leading to oxidative stress. Resveratrol (RSV) is a polyphenolic compound that has been shown to act as an antioxidant in medical practice.

Objective: To verify the antioxidant action of resveratrol (and its correlation with aging) in leukocytes from donors of different ages, mainly through the analysis of the three main enzymes of the antioxidant complex and the analysis of the SIRT1 signaling pathway.

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One of the causes for aging is free radical damage. Resveratrol (RSV), a polyphenolic compound has been shown to act as an antioxidant and anti-inflammatory. The objective this study was to verify in an oxidative stress environment in Human Mononuclear cells from Middle aged and Elderly donors, the existence of a change in the SIRT1 and AMPK signaling pattern by RSV.

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Aging is characterized by a progressive loss of physiological integrity. One common denominator is the increase of reactive oxygen species (ROS) caused by inhibition of important antioxidant pathways. Resveratrol is a polyphenol known for its potent antioxidant activity.

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Diabetes mellitus is a metabolic disorder that causes severe complications due to the increased oxidative stress induced by disease. Many plants are popularly used in the treatment of diabetes, e.g.

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Baccharis trimera, popularly known as "carqueja", is a native South-American plant possessing a high concentration of polyphenolic compounds and therefore high antioxidant potential. Despite the antioxidant potential described for B. trimera, there are no reports concerning the signaling pathways involved in this process.

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Background: Acetaminophen (APAP) is a commonly used analgesic and antipyretic. When administered in high doses, APAP is a clinical problem in the US and Europe, often resulting in severe liver injury and potentially acute liver failure. Studies have demonstrated that antioxidants and anti-inflammatory agents effectively protect against the acute hepatotoxicity induced by APAP overdose.

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Acetaminophen is a common analgesic and antipyretic compound which, when administered in high doses, has been associated with significant morbidity and mortality, secondary to hepatic toxicity. Although this may be due to a direct interaction of reactive acetaminophen metabolites with hepatocyte proteins, recent studies have suggested that reactive species produced by neutrophils also contribute to the pathophysiological process. Researches on the chemical composition of B.

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Objectives: To evaluate the correlation between reactive oxygen species (ROS) production and micronucleus formation induced by a vitamin complex in peripheral blood mononuclear cells from healthy people aged between 40 and 85 years old.

Methods: Peripheral blood mononuclear cells (PBMNCs) were purified utilizing ficoll-hypaque gradient. ROS production by PBMNCs was quantified by luminol-dependent chemiluminescence in the presence or in the absence of the vitamin complex.

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Background: Diabetic patients are exposed to increased oxidative stress due to several mechanisms, mainly hyperglycaemia. Pathological processes, such as those in type 1 diabetes, include diminished activity of the antioxidant defense system(s) or excessive oxidative generation resulting in an oxidative/antioxidant imbalance and development of oxidative stress.

Methods: The purpose of this study was to evaluate the production of reactive oxygen species (ROS) (chemiluminescence) and reduction capacity (MTT dye reduction), the expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits, superoxide dismutase and catalase using quantitative reverse-transcriptase polymerase chain reaction, and the levels of cytokines [interleukin (IL)-6, tumour necrosis factor-α, IL-8, IL-10 and IL-4] by sandwich enzyme-linked immunosorbent assay in mononuclear cells from non-diabetic and diabetic donors treated with a vitamin complex (ascorbic acid, β-carotene and α-tocopherol) in two different concentrations ([A] = ascorbic acid = 0.

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Aim: To evaluate the antioxidant capacity and concentrations of vascular endothelial growth factor (VEGF) and interleukin 6 (IL-6) in aqueous humor from patients with type 2 diabetes mellitus (T2DM) with or without retinopathy.

Methods: Aqueous humor was obtained during elective cataract surgery from T2DM patients with or without retinopathy and from healthy subjects. Reducing response was evaluated by MTT dye reduction and the generation of reactive oxygen species (ROS) was determined by chemiluminescence assay.

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Objectives: The in vitro effect of a vitamin complex in generating and reducing oxidative species in peripheral blood mononuclear cells (PBMNC) and plasma of patients with Alzheimer's disease (AD) and healthy subjects (HS) was evaluated.

Methods: Two concentrations of a vitamin complex ([A] and [20A]) with ascorbic acid, alpha-tocopherol, and beta-carotene were incubated with either mononuclear cells or plasma. The generation of oxidizing species was measured in a luminol-dependent chemiluminescence assay and the reducing response by the MTT dye reduction assay.

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Annatto has been identified as carotenoids that have antioxidative effects. It is well known that one of the key elements in the development of diabetic complications is oxidative stress. The immune system is especially vulnerable to oxidative damage because many immune cells, such as neutrophils, produce reactive oxygen species and reactive nitrogen species as part of the body's defense mechanisms to destroy invading pathogens.

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Annatto (Bixa orellana L.) contains a mixture of orange-yellowish pigments due to the presence of various carotenoids that have antioxidant effect. The immune system is especially vulnerable to oxidative damage because many immune cells, such as neutrophils, produce reactive oxygen and nitrogen species (ROS and RNS) as part of the body's defence mechanisms to destroy invading pathogens.

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The aim of this study was to investigate the possible effects of captopril as a promoter in modulating the oxidant-antioxidant balance in rats with type 1 diabetes, and the influence of protein kinase C (PKC) pathways in the production of reactive oxygen species (ROS) induced by bradykinin in type 1 diabetic rats. This study evaluated the redox status in both the cardiac tissue and at the cellular level (neutrophils). Two concentrations of captopril were utilized: (i) 5 mg·(kg body mass)(-1), which was considered a therapeutic dose; and (ii) 10 mg·(kg body mass)(-1).

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Introduction: Despite advances in treatment of diabetes mellitus, its prevalence continues to rise globally. Medications available are unable to control the vascular complications. Proposals for new therapeutic targets must take into account the hyperglycemia-induced signaling pathways that give rise to the inflammatory profile of the disease.

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Peripheral blood mononuclear cells (PBMNC) from patients with type 2 diabetes (DM2) have generated higher levels of reactive oxygen species (ROS) that were higher than those in cells from healthy individuals. In the presence of a cAMP-elevating agent, ROS production was significantly activated in PBMNC from DM2 patients but it was inhibited in cells from healthy subjects. Higher levels of IL-6 has been detected in the supernatant of PBMNC cultures from DM2 patients in comparison with healthy controls.

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The aging of organisms is characterized by a gradual functional decline of all organ systems. An appropriate theory must explain four main characteristics of aging: it is progressive, endogenous, irreversible, and deleterious for the individual. The aging of the immune system, or immunosenescence, is manifested by an increased susceptibility to infections with increased morbidity and mortality.

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Ethnopharmacological Relevance: Baccharis trimera (Less.) (Asteraceae) is a native plant of Brazil. Also known as "carqueja", it has been popularly used to treat liver diseases, diabetes, as well as digestive disorders.

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Background: There is a large increase in the number of elderly people in modern societies. This demographic phenomenon has been paralleled by an epidemic of chronic diseases and inflammatory processes usually associated with advanced age.

Objective: We studied the role of protein kinase A (PKA), protein kinase B (Akt/PKB) and p38 mitogen-activated protein kinase (p38 MAPK) signaling pathways in ROS produced by neutrophils induced by pro-interferon-gamma (IFN-gamma) or anti-inflammatory interleukin 10 (IL-10) cytokines age-related.

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Background: Diabetes mellitus constitutes a serious public health problem. Recent advances in therapies are unable to control its vascular complications. New medications have been suggested but without comprehensive knowledge of the signaling pathways induced by hyperglycemia.

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