The aim of this work was to examine the mechanisms involved in the in vivo antioxidant effects of epicatechin (EC), a major flavonoid in the human diet. The influence of EC in different oxidative biomarkers (reactive oxygen species (ROS) production, intracellular glutathione, activity of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD)) was studied in the model organism Caenorhabditis elegans . Under thermal stress condition, exposure of the worms (wild type N2 strains) to EC (200 μM) significantly reduced ROS levels (up to 28%) and enhanced the production of reduced glutathione (GSH). However, no significant changes were appreciated in the activities of GPx, CAT, and SOD, suggesting that further activation of these antioxidant enzymes was not required once the concentration of ROS in the EC-treated worms was restored to what could be considered physiological levels.
Dietary flavonoids have been associated with a lower incidence of some chronic diseases. However, the mechanisms behind the in vivo biological activity of flavonoids are still mostly unknown. Flavonoids are metabolized in the human body to conjugated forms (methylated, sulphated and glucuronidated derivatives) that should play a role in flavonoid activity. In this study, the anti-proliferative effects of conjugated metabolites of quercetin and (epi)catechin, major flavonoids in the diet, have been evaluated against three different cancer cell lines from breast (MCF-7), colon (Caco-2) and pancreas (BxPC-3) and one normal cell line of human foreskin fibroblasts (HFF-1), and compared with the effect of their unconjugated forms. Quercetin showed anti-proliferative activity on the three assayed cell models, whereas catechin and epicatechin were not active. Methylation on ring-B of quercetin decreased the anti-proliferative effects, especially when the methylation occurred in position 3' (isorhamnetin), although methylated metabolites still showed significant anti-proliferative activity. As to catechins, 4'-O-methyl-epicatechin and 3'-O-methyl-epicatechin were the only ones to show some activity on MCF-7 and BxPC-3 cell lines, respectively. Conjugation of quercetin with glucose or glucuronic acid eliminated the anti-proliferative effects of aglycones. Sulphated metabolites were also tested and found to be inactive in most of the explored cell lines, although quercetin-4'-O-sulphate and epicatechin-3'-O-sulphate still showed some anti-proliferative activity on MCF-7 and Caco-2 cells, respectively.
Enhanced surveillance, such as the one shown in this study, would help the early identification of nonindigenous Plasmodium species and also of resistant Plasmodium strains with a potential to spread locally. Population mobility and imported malaria cases may add to the magnitude of malaria burden in some regions of Latin America. Furthermore, malaria treatment guidelines at local and national levels need to incorporate imported malaria cases in their treatment algorithms and into chemoprophylactic recommendations for travelers.
Climate Change is the most important threat to our society and all species on Earth. Large alterations in the climate are affecting every aspect of our society and in order to limit this impact we must decarbonize the economy before 2050. Although science presents solid evidence on the magnitude of the problem and outlines precisely the consequences, people do not act accordingly and do not consider this issue a priority for their survival. The reason behind this paradox might be a non-appropriate Social Representation of Climate Change in society as the Social Representation conditions and forms the response of the society. In this paper, we extend previous investigations of how this Social Representation is formed in order to find ways to improve it through a Massive Online Open Course on the Science of Climate Change. Using a validated questionnaire, we investigated the knowledge dimension of the Social Representation of Climate Change in a group of students of a MOOC on Climate Change. A pre- and posttest revealed general improvements in all the categories that were considered in this study. A detailed analysis showed different degrees of improvement for different groups, providing new insights in the efficiency of knowledge-based online courses. Well designed Massive Online Open Courses, based on scientific evidence, targeted to the general public might improve the Social Representation of Climate Change, which may in turn trigger awareness and an effective mobilization to address this important and urgent topic.
The Semantic Life of Proper Names * 1 Introduction Historically, theorizing on proper names has had the tendency of oscillating between two extremes: thinking of proper names as unambiguous individual constants in the formal language, and thinking of proper names as definite descriptions. Since Kripke, the orthodoxy has been to treat names as individual constants. However, the orthodoxy faces two anomalies: on the one hand, proper names can have multiple bearers. But multiple bearerhood is (prima facie) a problem to the idea that proper names have just one individual as referent. On the other hand, as Burge (1973) noted, proper names can have predicative uses. But the view that proper names are singular terms arguably does not have the resources to deal with Burge's cases. * An earlier version of substantial part of this paper were already present in my Bphil dissertation "Between Singularity and Generality: The Semantic Life of Proper Names"
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.