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Chemical investigation of the leaves of Manniophyton fulvum led to the isolation of seven flavonoid glycosides: myricetin-3-O-β- Dd -rhamnoside (1), kaempferol-3-O-β- d -rhamnoside (2), quercetin-3-O-β- d -glucoside (3), quercetin-3-O-β- d -rhamnoside (4), quercetin-3-O-β- d -galactoside (5), rutin (6) and quercetin (7). The structures of the compounds were established by spectroscopic analyses as well as by comparison with published data. Some of the compounds showed strong antioxidant activity which validates the traditional use of the plant. An attempted correlation between the computed HOMO-LUMO energies and the measured antioxidant activities was established. We have also estimated the cardiotoxicity of the compounds by calculating the predicted logarithm of the human Ether-`a-go-go Related Gene (loghERG) using the QikProp program. These purified flavonoids are new potential lead compounds for the development of antioxidant drugs.

The World Health Organization has recommended performing at least 60 min a day of moderate-to-vigorous physical activity (MVPA) and reducing sedentarism in children and adolescents to offer significant health benefits and mitigate health risks. Physical fitness and sports practice seem to improve oxidative stress (OS) status during childhood. However, to our knowledge, there are no data regarding the influence of objectively-measured physical activity (PA) and sedentarism on OS status in children and adolescents. The present study aimed to evaluate the influence of moderate and vigorous PA and sedentarism on OS and plasma total antioxidant capacity (TAC) in a selected Spanish population of 216 children and adolescents from the GENOBOX study. PA (light, moderate, and vigorous) and sedentarism (i.e., sedentary time (ST)) were measured by accelerometry. A Physical Activity-Sedentarism Score (PASS) was developed integrating moderate and vigorous PA and ST levels. Urinary 8-hydroxy-20-deoxyguanosine (8-OHdG) and isoprostane F2 (F2-IsoPs), as markers of OS, were determined by ELISA; and TAC was estimated by colorimetry using an antioxidant kit. A higher PASS was associated with lower plasma TAC and urinary 8-OHdG and F2-IsoPs, showing a better redox profile. Reduced OS markers (8-OHdG and F2-IsoPs) in children with higher PASS may diminish the need of maintaining high concentrations of antioxidants in plasma during rest to achieve redox homeostasis., Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I + D + I), Instituto de Salud Carlos III-Health Research Funding (FONDOS FEDER) PI11/02042 PI11/02059 PI11/01425 PI16/00871 PI16/01301 PI16/01205, RETIC (Redes temáticas de investigación cooperativa) Red SAMID RD12/0026/0015, Instituto de Salud Carlos III European Commission IFI17/00048, Research Plan of the Vice-Rectorate of Research and Transfer of the University of Granada, Spain

International audience; In recent years there has been enormous interest in researching oxidative stress. Reactive oxygen species (ROS) are derived from the metabolism of oxygen as by-products of cell respiration, and are continuously produced in all aerobic organisms. Oxidative stress occurs as a consequence of an imbalance between ROS production and the available antioxidant defence against them. Nowadays, a variety of diseases and degenerative processes such as cancer, Alzheimer’s and autoimmune diseases are mediated by oxidative stress. Heat stress was suggested to be an environmental factor responsible for stimulating ROS production because of similarities in responses observed following heat stress compared with that occurring following exposure to oxidative stress. This manuscript describes the main mitochondrial sources of ROS and the antioxidant defences involved to prevent oxidative damage in all the mitochondrial compartments. It also deals with discussions concerning the cytotoxic effect of heat stress, mitochondrial heat-induced alterations, as well as heat shock protein (HSP) expression as a defence mechanism.