Organic grape juice intake improves functional capillary density and postocclusive reactive hyperemia in triathletes

OBJECTIVE: The aim of this study was to evaluate the effect of organic grape juice intake on biochemical variables and microcirculatory parameters in triathlon athletes. INTRODUCTION: The physiological stress that is imposed by a strenuous sport, such as a triathlon, together with an insufficient amount of antioxidants in the diet may cause oxidative imbalance and endothelial dysfunction. METHODS: Ten adult male triathletes participated in this study. A venous blood sample was drawn before (baseline) and after 20 days of organic grape juice intake (300 ml/day). Serum insulin, plasma glucose and uric acid levels, the total content of polyphenols, and the erythrocyte superoxide dismutase activity were determined. The functional microcirculatory parameters (the functional capillary density, red blood cell velocity at baseline and peak levels, and time required to reach the peak red blood cell velocity during postocclusive reactive hyperemia after a one-min arterial occlusion) were evaluated using nailfold videocapillaroscopy. RESULTS: Compared with baseline levels, the peak levels of serum insulin ( p = 0.02), plasma uric acid ( p = 0.04), the functional capillary density ( p = 0.003), and the red blood cell velocity (p < 0.001) increased, whereas the plasma glucose level (p,0.001), erythrocyte superoxide dismutase activity ( p = 0.04), and time required to reach red blood cell velocity during postocclusive reactive hyperemia ( p = 0.04) decreased after organic grape juice intake. CONCLUSION: Our data showed that organic grape juice intake improved glucose homeostasis, antioxidant capacity, and microvascular function, which may be due to its high concentration of polyphenols. These results indicate that organic grape juice has a positive effect in endurance athletes

Contribution of Yap 1 towards S. cervisiae adaptation to arsenic mediated oxidative stress

Post-PrintIn the budding yeast Saccharomyces cerevisiae arsenic detoxification involves the activation Yap8, a member of the Yap family of transcription factors, which in turn regulates ACR2 and ACR3, encoding an arsenate reductase and a plasma membrane arsenite efflux-protein, respectively. In addition, Yap1 is involved in the arsenic adaptation process through regulating the expression of the vacuolar-pump encoded by YCF1 and also contributing to the regulation of ACR genes. Here we show that Yap1 is also involved in the removal of ROS generated by arsenic compounds. Data on lipid peroxidation and intracellular oxidation indicate that deletion of YAP1 and YAP8 triggers cellular oxidation mediated by inorganic arsenic. In spite of the increased amounts of As(III) absorbed by the yap8 mutant, the enhanced transcriptional activation of the antioxidant genes such as GSH1, SOD1 and TRX2 may prevent protein oxidation. In contrast, the yap1 mutant exhibits high contents of protein carbonyl groups and the GSSG:GSH ratio is severely disturbed upon exposure to arsenic compounds in these cells. These results point to an additional level of Yap1 contribution to arsenic stress responses by preventing oxidative damage in cells exposed to these compounds. Transcriptional profiling revealed that genes of the functional categories related with sulphur and methionine metabolism and with the maintenance of the cell redox homeostasis are activated to mediate adaptation of the wild type strain to 2 mM arsenate treatmen

Saccharomyces cerevisiae geneticamente modificada e seu uso

DepositadaA inovação ora proposta diz respeito à levedura Saccharomyces cerevisiae geneticamente modificada por meio da inserção via plasmidial (pYEP-PGK) do gene xylA da bactéria Burkholderia cenocepacia, que proporciona à levedura modificada a expressão da enzima xilose isomerase. A presente invenção inclui ainda o uso das ditas leveduras geneticamente modificadas na fermentação de glicose e xilose de hidrolisados de biomassa, como o bagaço da cana-de-açúcar, para a produção de etanol

Stress modulation as a means to improve yeasts for lignocellulose bioconversion

The second-generation (2G) fermentation environment for lignocellulose conversion presents unique challenges to the fermentative organism that do not necessarily exist in other industrial fermentations. While extreme osmotic, heat, and nutrient starvation stresses are observed in sugar- and starch-based fermentation environments, additional pre-treatment-derived inhibitor stress, potentially exacerbated by stresses such as pH and product tolerance, exist in the 2G environment. Furthermore, in a consolidated bioprocessing (CBP) context, the organism is also challenged to secrete enzymes that may themselves lead to unfolded protein response and other stresses. This review will discuss responses of the yeast Saccharomyces cerevisiae to 2G-specific stresses and stress modulation strategies that can be followed to improve yeasts for this application. We also explore published –omics data and discuss relevant rational engineering, reverse engineering, and adaptation strategies, with the view of identifying genes or alleles that will make positive contributions to the overall robustness of 2G industrial strains