Cellular Dysfunction in Diabetes as Maladaptive Response to Mitochondrial Oxidative Stress

Oxidative stress has been implicated in diabetes long-term complications. In this paper, we summarize the growing evidence suggesting that hyperglycemia-induced overproduction of superoxide by mitochondrial electron transport chain triggers a maladaptive response by affecting several metabolic and signaling pathways involved in the pathophysiology of cellular dysfunction and diabetic complications. In particular, it is our goal to describe physiological mechanisms underlying the mitochondrial free radical production and regulation to explain the oxidative stress derived from a high intracellular glucose concentration and the resulting maladaptive response that leads to a cellular dysfunction and pathological state. Finally, we outline potential therapies for diabetes focused to the prevention of mitochondrial oxidative damage

Adipose Tissue Mitochondrial Factors Profile after Dietary Bioactive Compound Weight Reduction Treatments in a Mice Obesity Model

Prolonged caloric intake above energy needs disturbs the body’s ability to store and manage the excess of energy intake, leading to the onset of chronic degenerative diseases. This study aimed to compare the effect of three foods, which contain demonstrated bioactive compounds in the treatment of obesity and as an adjuvant in obesity energy restriction treatments. In a mice obesity model induced through a high-fat diet; fish oil, soluble fibre, and soy were incorporated to evaluate its capacity to modulate metabolic factors in adipose tissue during a continued fat intake or weight reduction through a normocaloric diet. As a result, fish oil improved mitochondrial related, adipose tissue hormone expression, and oxidation products when high-fat diets are consumed; while soluble fibre improved glucose and inflammation pathways during high-fat diet intake. In weight reduction treatments few differential features, as a treatment adjuvant, were observed for fish oil and soy; while soluble fibre was able to improve the weight reduction effects induced by a normocaloric diet. As a conclusion, soluble fibre supplementation compared to an energy reduction program, was the only treatment able to induce a significant additional effect in the improvement of weight loss and adipose tissue metabolism.</jats:p

Beverage Type and Hydration Parameters in Older Persons Following a Texture-Modified Diet and Living in Long-term Care Residences

Abstract Background: Dehydration due to insufficient fluid intake is a common feature in older adults, a situation that is exacerbated in those who follow a texture modified diet. Most studies have been focused on the total amount of fluid intake without taking into consideration hydration capacities from different beverages. This study aimed to evaluate which is the relationship between the intake of different beverage types and their relationship with hydration parameters in older adults. Methods: A prospective observational study in 22 volunteers that followed a texture-modified diet and thickened liquids with a monthly follow-up for 4 months was performed with older people living in long-term care residences. Beverage intake was assessed daily, and hydration parameters were determined at the end of each month. Results: 50% of the volunteers presented an inadequate fluid intake (&lt; 90% of the recommended daily intake of 30 mL/kg of body weight). Gelatine was the preferred hydration drink, providing 54% of the water intake outside the diet, while water and fruit juices constituted approximately 18% of the intake each, and other beverages such as milk and yogurt, the remaining 10%. No correlation was observed between the total amounts of liquids taken during the day with any of the biomarkers of hydration analysed. Contrary, plain water intake inversely correlated with blood levels of sodium (r= -0.25), and Angiotensin-Converting-Enzyme (ACE) activity (r= -0.29); while gelatine directly correlated with haematocrit (r= 0.25). Since different beverages were consumed during the day, cluster analysis was performed to determine patterns of beverage intake. Three patterns of beverage intake were identified, mainly high in plain water, high in gelatine, and mixed beverage intake. The pattern with a higher intake of gelatine, as a source of water, reported the worst parameters of hydration. Similarly, it was observed that a pattern with high plain water intake showed higher levels of fluid intake. Conclusions: It was concluded that besides the focus on total fluid intake, an appropriate selection of beverages is another important criterion that should be taken into consideration for hydration in older people.</jats:p

Effect of Dietary Bioactive Compounds on Mitochondrial and Metabolic Flexibility

Metabolic flexibility is the capacity of an organism to adequately respond to changes in the environment, such as nutritional input, energetic demand, etc. An important player in the capacity of adaptation through different stages of metabolic demands is the mitochondrion. In this context, mitochondrial dysfunction has been attributed to be the onset and center of many chronic diseases, which are denoted by an inability to adapt fuel preferences and induce mitochondrial morphological changes to respond to metabolic demands, such as mitochondrial number, structure and function. Several nutritional interventions have shown the capacity to induce changes in mitochondrial biogenesis/degradation, oxidative phosphorylation efficiency, mitochondrial membrane composition, electron transfer chain capacity, etc., in metabolic inflexibility states that may open new target options and mechanisms of action of bioactive compounds for the treatment of metabolic diseases. This review is focused in three well-recognized food bioactive compounds that modulate insulin sensitivity, polyphenols, ω-3 fatty acids and dietary fiber, by several mechanism of action, like caloric restriction properties and inflammatory environment modulation, both closely related to mitochondrial function and dynamics

Characterization of antioxidant properties and metabolite profile of Agave atrovirens extracts

Agave spp. is widely analyzed because several functional properties have been described. Some minor bioactive compounds such as polyphenols, saponins and Maillard compounds produced during extraction procedures have been reported to exert antioxidant properties. The objective of this study was to elucidate the antioxidant properties of three different Agave atrovirens extracts in a HepG2 cell culture assay. The three extracts analyzed mostly showed antioxidant properties with an increase in NRF2 content in nuclear extracts. However, a differential response was observed in the reduction of protein oxidative damage in the three extracts analyzed, the crude extract being the one that mainly induced a reduction in oxidative damage. Metabolomic analysis was performed to elucidate the potential molecules responsible for the antioxidant properties, where 2-amino-4-methylphenol could be the main candidate responsible for inducing the transcription of cellular antioxidant response elements. It could be concluded that crude extract of Agave atrovirens may increase the cellular antioxidant defense system, with a reduction in oxidative damage.</jats:p

Double-edged sword behaviour of gallic acid and its interaction with peroxidases in human microvascular endothelial cell culture (HMEC-1). Antioxidant and pro-oxidant effects.

A previous report from our group had shown in vitro a direct interaction between peroxidases and dietary antioxidants at physiological concentrations, where in the absence of H(2)O(2), the antioxidants could serve as oxidizing substrates for the peroxidases. However, the physiological relevance of those findings had not been evaluated. The main objective of this study was to determine whether the oxidizing products produced in the interaction between peroxidase and gallic acid at a physiological concentration of 1 microM may promote cell death or survival in a human microvascular endothelial cell line (HMEC-1). Our findings suggested that gallic acid may show a double-edged sword behaviour, since in the absence of H(2)O(2) it may have a pro-oxidant effect which may promote cell injury (evidenced by LDH, Crystal Violet and calcein AM viability/citotoxicity assays), while in the presence of H(2)O(2), gallic acid may act as an antioxidant inhibiting oxidative species produced in the peroxidase cycle of peroxidases. These observations were confirmed with several oxidative stress biomarkers and the evaluation of the activation of cell survival pathways like AKT and MAPK/ERK.</jats:p