Chondroitin Sulfate from Oreochromis niloticus Waste Reduces Leukocyte Influx in an Acute Peritonitis Model.

Oreochromis niloticus (tilapia) is one of the most cultivated fish species worldwide. Tilapia farming generates organic waste from fish removal processes in nurseries. Visceral waste can damage natural ecosystems. Therefore, the use of this material as a source of biomolecules helps reduce environmental impacts and improve pharmacological studies. Tilapia viscera were subjected to proteolysis and complexation with an ion-exchange resin. The obtained glycosaminoglycans were purified using ion exchange chromatography (DEAE-Sephacel). The electrophoretic profile and analysis of 1H/13C nuclear magnetic resonance (NMR) spectra allowed for the characterization of the compound as chondroitin sulfate and its sulfation position. This chondroitin was named CST. We tested the ability of CST to reduce leukocyte influx in acute peritonitis models induced by sodium thioglycolate and found a significant reduction in leukocyte migration to the peritoneal cavity, similar to the polymorphonuclear population of the three tested doses of CST. This study shows, for the first time, the potential of CST obtained from O. niloticus waste as an anti-inflammatory drug, thereby contributing to the expansion of the study of molecules with pharmacological functions.

Antioxidant Activity of Fucoidan Modified with Gallic Acid Using the Redox Method.

Antioxidant compounds decrease the amount of intracellular reactive oxygen species (ROS) and, consequently, reduce the deleterious effects of ROS in osteoblasts. Here, we modified a 21 kDa fucoidan (FucA) with gallic acid (GA) using the redox method, to potentiate its antioxidant/protective capacity on pre-osteoblast-like cells (MC3T3) against oxidative stress. The 20 kDa FucA-GA contains 37 ± 3.0 mg GA per gram of FucA. FucA-GA was the most efficient antioxidant agent in terms of total antioxidant capacity (2.5 times), reducing power (five times), copper chelation (three times), and superoxide radical scavenging (2 times). Exposure of MC3T3 cells to H2O2 increased ROS levels and activated caspase-3 along with caspase-9. In addition, the cell viability decreased approximately 80%. FucA-GA also provided the most effective protection against oxidative damage caused by H2O2. Treatment with FucA-GA (1.0 mg/mL) increased cell viability (~80%) and decreased intracellular ROS (100%) and caspase activation (~80%). In addition, Fuc-GA (0.1 mg/mL) abolished H2O2-induced oxidative stress in zebra fish embryos. Overall, FucA-GA protected MC3T3 cells from oxidative stress and could represent a possible adjuvant for the treatment of bone fragility by counteracting oxidative phenomena.

Ocorrência de casos de raiva em animais silvestres no município de Caicó-RN no período de 2014 a 2019 / Occurrence of rabies cases in the wild animals, in Caicó/RN, from 2014 to 2019

A saúde humana está intimamente ligada à saúde do ambiente e dos animais, sendo de extrema importância a consideração dessa relação nas tomadas de decisão que impliquem em mudanças positivas nos determinantes sociais de saúde. Nesse contexto, a raiva é uma zoonose que tem ocorrido no município de Caicó/RN e tem colocado a cidade entre as primeiras em número de casos em animais silvestres do estado. O presente trabalho objetivou relatar a ocorrência de casos de raiva em animais silvestres nesse município, no período de janeiro de 2014 a julho de 2019. Realizou-se um estudo epidemiológico transversal e descritivo do tipo de série temporal, retrospectivo e quantitativo. Foram utilizados dados secundários, fornecidos pelo LACEN/RN e CCZ, referentes à casuística de raiva em animais silvestres capturados através da vigilância passiva da raiva e submetidos a provas de Imunofluorescência Direta e Inoculação Intracerebral em Camundongos. Foram confirmados 26 casos de raiva em animais silvestres, sendo 21 casos em morcegos (80,76%) e 5 em raposas (19,24%). Apenas essas duas espécies silvestres, morcegos e raposas, foram diagnosticadas positivamente para a doença. Uma variante silvestre comumente encontrada em raposas foi identificada em um cão. A confirmação de casos positivos de raiva em animais silvestres indica que existe a circulação do vírus rábico no município de Caicó, chamando atenção para o risco de exposição de animais domésticos e da população. Diante disso, é de suma importância que o poder público subsidie o funcionamento dos serviços de vigilância para evitar a propagação da doença.

Human health is closely linked to the health of the environment and animals, and it is extremely important to consider this relationship in decision-making that imply positive changes in social determinants of health. In this context, rabies is a zoonosis that has occurred in the municipality of Caicó-RN and has placed the city among the first in number of cases in wild animals in the state. This study aimed to report the occurrence of cases of rabies in wild animals in this municipality, from January 2014 to July 2019. A cross-sectional and descriptive epidemiological study of the type of time series, retrospective and quantitative, was carried out. Secondary data provided by LACEN / RN and CCZ regarding rabies casuistry in wild animals captured through passive rabies surveillance and subjected to Direct Immunofluorescence and Intracerebral Inoculation in Mice tests were used. 26 cases of rabies in wild animals were confirmed, 21 cases in bats (80.76%) and 5 in foxes (19.24%). Only these two wild species have been positively diagnosed for the disease. A wild variant commonly found in foxes, has been identified in a dog. The confirmation of positive cases of rabies in wild animals indicates that the circulation of the rabies virus exists in the municipality of Caicó, calling attention to the risk of exposure of domestic animals and the population. In view of this, it is of utmost importance that the public authorities subsidize the operation of surveillance services to prevent the spread of the disease.

Antioxidant Sulfated Polysaccharide from Edible Red Seaweed Gracilaria birdiae is an Inhibitor of Calcium Oxalate Crystal Formation.

The genus Gracilaria synthesizes sulfated polysaccharides (SPs). Many of these SPs, including those synthesized by the edible seaweed Gracilaria birdiae, have not yet been adequately investigated for their use as potential pharmaceutical compounds. Previous studies have demonstrated the immunomodulatory effects of sulfated galactans from G. birdiae. In this study, a galactan (GB) was extracted from G. birdiae and evaluated by cell proliferation and antioxidant tests. GB showed no radical hydroxyl (OH) and superoxide (O2-) scavenging ability. However, GB was able to donate electrons in two further different assays and presented iron- and copper-chelating activity. Urolithiasis affects approximately 10% of the world's population and is strongly associated with calcium oxalate (CaOx) crystals. No efficient compound is currently available for the treatment of this disease. GB appeared to interact with and stabilize calcium oxalate dihydrate crystals, leading to the modification of their morphology, size, and surface charge. These crystals then acquired the same characteristics as those found in healthy individuals. In addition, GB showed no cytotoxic effect against human kidney cells (HEK-293). Taken together, our current findings highlight the potential application of GB as an antiurolithic agent.

In Vitro Studies Reveal Antiurolithic Effect of Antioxidant Sulfated Polysaccharides from the Green Seaweed Caulerpa cupressoides var flabellata.

Urolithiasis affects approximately 10% of the world population and is strongly associated with calcium oxalate (CaOx) crystals. Currently, there is no efficient compound that can be used to prevent this disease. However, seaweeds' sulfated polysaccharides (SPs) can change the CaOx crystals surface's charge and thus modify the crystallization dynamics, due to the interaction of the negative charges of these polymers with the crystal surface during their synthesis. We observed that the SPs of Caulerpa cupressoides modified the morphology, size and surface charge of CaOx crystals. Thus, these crystals became similar to those found in healthy persons. In the presence of SPs, dihydrate CaOx crystals showed rounded or dumbbell morphology. Infrared analysis, fluorescence microscopy, flow cytometry (FITC-conjugated SPs) and atomic composition analysis (EDS) allowed us to propose the mode of action between the Caulerpa's SPs and the CaOx crystals. This study is the first step in understanding the interactions between SPs, which are promising molecules for the treatment of urolithiasis, and CaOx crystals, which are the main cause of kidney stones.

In Vivo Evaluation of the Antioxidant Activity and Protective Action of the Seaweed Gracilaria birdiae.

The red seaweed Gracilaria birdiae (GB) is farmed and used as food in northeast Brazil. However, the economic potential of this seaweed has been explored little. To enable direct consumption and/or product diversification from GB, it is necessary to evaluate its effect in vivo. In this study, the food of mice was improved with the addition of GB. After 21 days, the consumption of seaweed reduced the weight gain and blood glucose levels in mice. In addition, it increased the trolox equivalent antioxidant capacity and glutathione reductase and catalase levels compared to those of the control group. In addition, some mice also received carbon tetrachloride (CCl4). In this case, histological, enzymatic, and antioxidant tests showed that the seaweed could protect animals from damage caused by this toxic agent. In addition, GB aqueous extract (AE) inhibited 50% of 3T3-L1 cell differentiation into adipocytes, whereas GB ethanolic extract was not effective. AE is composed mainly of sulfated polysaccharides. The results of the present study indicate that the alga GB protected the mice from CCl4-induced damage, indicating that the seaweed exhibits protective action in vivo. In addition, GB decreased the animal weight gain, which was mainly due to the action of the sulfated polysaccharides synthesized by this seaweed.

Commercial Fucoidans from Fucus vesiculosus Can Be Grouped into Antiadipogenic and Adipogenic Agents.

Fucus vesiculosus is a brown seaweed used in the treatment of obesity. This seaweed synthesizes various bioactive molecules, one of them being a sulfated polysaccharide known as fucoidan (FF). This polymer can easily be found commercially, and has antiadipogenic and lipolytic activity. Using differential precipitation with acetone, we obtained four fucoidan-rich fractions (F0.5/F0.9/F1.1/F2.0) from FF. These fractions contain different proportions of fucose:glucuronic acid:galactose:xylose:sulfate, and also showed different electrophoretic mobility and antioxidant activity. Using 3T3-L1 adipocytes, we found that all samples had lipolytic action, especially F2.0, which tripled the amount of glycerol in the cellular medium. Moreover, we observed that FF, F1.0, and F2.0 have antiadipogenic activity, as they inhibited the oil red staining by cells at 40%, 40%, and 50%, respectively. In addition, they decreased the expression of key proteins of adipogenic differentiation (C/EBPα, C/EBPß, and PPARγ). However, F0.5 and F0.9 stimulated the oil red staining at 80% and increased the expression of these proteins. Therefore, these fucoidan fractions have an adipogenic effect. Overall, the data show that F2.0 has great potential to be used as an agent against obesity as it displays better antioxidant, lipolytic and antiadipogenic activities than the other fucoidan fractions that we tested.

Genotoxicity and osteogenic potential of sulfated polysaccharides from Caulerpa prolifera seaweed.

Marine algae are sources of novel bioactive molecules and present a great potential for biotechnological and biomedical applications. Although green algae are the least studied type of seaweed, several of their biological activities have already been described. Here, we investigated the osteogenic potential of Sulfated Polysaccharide (SP)-enriched samples extracted from the green seaweed Caulerpa prolifera on human mesenchymal stem cells isolated from Wharton jelly (hMSC-WJ). In addition, the potential genotoxicity of these SPs was determined by cytokinesis-block micronucleus (CBMN) assay. SP-enriched samples did not show significant cytotoxicity towards hMSCs-WJ at a concentration of up to 10µg/mL, and after 72h of exposure. SP enrichment also significantly increased alkaline phosphatase (ALP) activity, promoting calcium accumulation in the extracellular matrix. Among the SP-enriched samples, the CP0.5 subfraction (at 5µg/mL) presented the most promising results. In this sample, ALP activity was increased approximately by 60%, and calcium accumulation was approximately 6-fold above the negative control, indicating high osteogenic potential. This subfraction also proved to be non-genotoxic, according to the CBMN assay, as it did not induce micronuclei. The results of this study highlight, for the first time, the potential of these SPs for the development of new therapies for bone regeneration.

Baccharis trimera (Less.) DC Exhibits an Anti-Adipogenic Effect by Inhibiting the Expression of Proteins Involved in Adipocyte Differentiation.

Baccharis trimera (Less.) DC (gorse) is a plant popularly used for the treatment of obesity. In this study, we prepared three B. trimera extracts aqueous extract (AE), decoction (AE-D), and methanol extract (ME) and investigated their antioxidant effects in six different tests and their anti-adipogenic effect in 3T3-L1 cells. The extracts showed a dose-dependent antioxidant activity in all tests. AE was the most potent antioxidant in copper and ferric ion chelation assays, whereas AE-D was the most potent in superoxide and hydroxyl radical scavenging assays, reducing power assay, and total antioxidant capacity analysis. Only ME showed a cytotoxic effect against 3T3-L1 cells. Lipid accumulation decreased in 3T3-L1 adipocytes in the presence of AE and AE-D extracts (0.5 to 1.0 mg/mL). In addition, the extracts dramatically attenuated the levels of adipogenic transcriptional factors, including CCAAT enhancer-binding protein α (C/EBPα), CCAAT enhancer-binding protein ß (C/EBPß), and gamma receptors by peroxisome proliferators (PPARγ), during adipogenesis. AE-D (1.0 mg/mL) caused an approximately 90% reduction in the levels of these molecules. We propose that B. trimera has an anti-adipogenic effect and could be used in the development of functional foods.

Vivência integrada na comunidade: inserção longitudinal no Sistema de Saúde como estratégia de formação médica / Integrated experience in the community: longitudinal health care insertion as medical education strategy / Vivencia integrada en la comunidad: inserción longitudinal en el Sistema de Salud como estrategia de formación médica

Propostas inovadoras para o processo ensino-aprendizagem nos cursos de Medicina vêm sendo desenvolvidas em busca de uma formação profissional generalista, humanista e crítica. A partir da aprovação do Programa Mais Médicos (PMM), novas escolas foram criadas adotando metodologias de ensino ativas e promovendo maior integração ensinoserviço-comunidade. Este artigo é um relato de experiência sobre o desenvolvimento do módulo Vivência Integrada na Comunidade no curso de Medicina da Escola Multicampi de Ciências Médicas do Rio Grande do Norte, que oportuniza ao estudante uma inserção longitudinal no sistema de Saúde em municípios do interior do Nordeste. Essa proposta vem promovendo maior integração entre a universidade, os gestores e os trabalhadores da Saúde. A aposta é a de que este módulo poderá contribuir com a fixação do médico na região e fortalecer o sistema de Saúde no interior do Brasil.

Innovative teaching-learning process proposals for medical courses have been developed for generalist, humanistic, critical professional education. Beginning with approval of the More Doctors Program, new schools were created, adopting active teaching methodologies and promoting further community-service-teaching integration. This paper is an experience report on the development of the Integrated Experience in the Community module in the medical course at the Medical Sciences Multi-campuses College of Rio Grande do Norte, which provides students with longitudinal insertion opportunities in the healthcare system of the hinterland towns of the Northeast region. This proposed module has been promoting further integration between the university managers, and healthcare workers. The goal of this module is to contribute to securing physicians for in the region and strengthening the healthcare system in the Brazilian hinterland.

Se han desarrollado propuestas innovadoras para el proceso enseñanza-aprendizaje en los cursos de medicina a la búsqueda de una formación profesional generalista, humanista y crítica. A partir de la aprobación del Programa Más Médicos se crearon nuevas escuelas, adoptando metodologías de enseñanza activas y promoviendo una mayor integración enseñanza-serviciocomunidad. Este artículo es un relato de experiencia sobre el desarrollo del módulo "Vivencia integrada en la comunidad" en el curso de medicina de la Escuela Multicampi de Ciencias Médicas de Rio Grande do Norte que proporciona al estudiante una inserción longitudinal en el sistema de salud en municipios del interior del Nordeste de Brasil. Esta propuesta ha promovido una mayor integración entre la Universidad, los gestores y los trabajadores de la salud. La apuesta es que este módulo podrá contribuir con la fijación del médico en la región y fortalecer el sistema de salud en el interior de Brasil.

A Escola Multicampi de Ciências Médicas da Universidade Federal do Rio Grande do Norte, Brasil, no contexto do Programa Mais Médicos: desafios e potencialidades / The Multicampi School of Medical Sciences of the Federal University of Rio Grande do Norte, Brazil, in the context of the More Doctors Program: challenges and potentialities / La Escuela Multicampi de Ciencias Médicas de La Universidad Federal de Riop Grande do Norte, Brasil, en el contexto del Programa Más Médicos: desafíos e potencialidades

A proposta deste artigo é relatar criticamente a experiência institucional e curricular de implantação do curso de Medicina da Escola Multicampi de Ciências Médicas do Rio Grande do Norte, da Universidade Federal do Rio Grande do Norte (UFRN). Este relato se coloca como forma de documentar, monitorar e refletir sobre o desenvolvimento das ações de expansão de vagas e criação de novos cursos de Medicina em universidades federais, no âmbito do Programa Mais Médicos. Para tanto, foram descritas de maneira crítica as ações de ensino, pesquisa e extensão já desenvolvidas, além de apresentar uma visão geral do curso e da integração ensino-serviço-comunidade, destacando os êxitos logrados e os desafios no desenvolvimento das ações de ensino, pesquisa e extensão. Por fim, são apresentadas as dificuldades inerentes à implantação de novos cursos fora dos centros urbanos no Brasil.

This paper reports on the institutional and curricular experience of launching the Medical Course of the Multicampi School of Medical Sciences of the Federal University of Rio Grande do Norte (UFRN). This report is a way of documenting, monitoring and reflecting on the development of actions of expansion of seats and creation of new medical courses in federal universities, within the framework of the More Doctors Program. To that end, the teaching, research and extension actions already developed are critically described, as well as it is presented an overview of the course and the teaching-service-community integration, highlighting the achievements and challenges in the development of teaching, research and extension. Finally, we describe the difficulties inherent in the implantation of new courses outside urban centers in Brazil.

El objetivo de este artículo es relatar la experiencia institucional y curricular de implantación del curso de Medicina de la Escuela Multicampi de Ciencias Médicas de la Universidad Federal de Rio Grande do Norte, de la Universidad Federal de Rio Grande do Norte (UFRN). Se presenta como una forma de comentar, monitorear y reflexionar sobre el desarrollo de las acciones de expansión de plazas y creación de nuevos cursos de Medicina en universidades federales, en el ámbito del Programa Más Médicos. Para ello, se describen de manera crítica las acciones de enseñanza, investigación y extensión ya desarrolladas, además de presentar una visión general del curso y de la integración enseñanza-servicio-comunidad, destacando los éxitos conseguidos y los desafíos en el desarrollo de las acciones de enseñanza, investigación y extensión. Finalmente se presentan las dificultades inherentes a la implantación de nuevos cursos fuera de los centros urbanos en Brasil.

Proteolysis, NaOH and ultrasound-enhanced extraction of anticoagulant and antioxidant sulfated polysaccharides from the edible seaweed, Gracilaria birdiae.

The sulfated polysaccharides (SP) from the edible red seaweed, Gracilaria birdiae, were obtained using five different extraction conditions: Gracilaria birdiae 1 (GB1)-water; GB1s-water/sonication; GB1sp-water/sonication/proteolysis; GB2s-NaOH/sonication; and GB2sp-NaOH/sonication/proteolysis. The yield (g) increased in the following order: GB2sp>GB1sp>GB2s>GB1s>GB1. However, the amount of SP extracted increased in a different way: GB2sp>GB1>GB1sp>GB1s>GB2s. Infrared and electrophoresis analysis showed that all conditions extracted the same SP. In addition, monosaccharide composition showed that ultrasound promotes the extraction of polysaccharides other than SP. In the prothrombin time (PT) test, which evaluates the extrinsic coagulation pathway, none of the samples showed anticoagulant activity. While in the activated partial thromboplastin time (aPTT) test, which evaluates the intrinsic coagulation pathway, all samples showed anticoagulant activity, except GB2s. The aPTT activity decreased in the order of GB1sp>GB2sp>GB1>GB1s>GB2s. The total capacity antioxidant (TCA) of the SP was also affected by extraction condition, since GB2s and GB1 showed lower activity in comparison to the other conditions. In conclusion, the conditions of SP extraction influence their biological activities and chemical composition. The data revealed that NaOH/sonication/proteolysis was the best condition to extract anticoagulant and antioxidant SPs from Gracilaria birdiae.

Evaluation of sulfated polysaccharides from the brown seaweed Dictyopteris justii as antioxidant agents and as inhibitors of the formation of calcium oxalate crystals.

Oxalate crystals and other types of crystals are the cause of urolithiasis, and these are related to oxidative stress. The search for new compounds with antioxidant qualities and inhibitors of these crystal formations is therefore necessary. In this study, we extracted four sulfated polysaccharides, a fucoglucoxyloglucuronan (DJ-0.3v), a heterofucan (DJ-0.4v), and two glucans (DJ-0.5v and DJ-1.2v), from the marine alga Dictyopteris justii. The presence of sulfated polysaccharides was confirmed by chemical analysis and FT-IR. All the sulfated polysaccharides presented antioxidant activity under different conditions in some of the in vitro tests and inhibited the formation of calcium oxalate crystals. Fucan DJ-0.4v was the polysaccharide that showed the best antioxidant activity and was one of the best inhibitors of the crystallization of calcium oxalate. Glucan DJ-0.5v was the second most potent inhibitor of the formation of oxalate crystals, as it stabilized dehydrated oxalate crystals (less aggressive form), preventing them from transforming into monohydrate crystals (more aggressive form). The obtained data lead us to propose that these sulfated polysaccharides are promising agents for use in the treatment of urolithiasis.

Antioxidant and antiproliferative activities of heterofucans from the seaweed Sargassum filipendula.

Fucan is a term used to denominate a type of polysaccharide which contains substantial percentages of l-fucose and sulfate ester groups. We obtained five heterofucans from Sargassum filipendula by proteolytic digestion followed by sequential acetone precipitation. These heterofucans are composed mainly of fucose, glucose, glucuronic acid, galactose and sulfate. These fucans did not show anticoagulant activity in PT and aPTT tests. Their antioxidant activity was evaluated using the follow tests; total antioxidant capacity, scavenging hydroxyl and superoxide radicals, reducing power and ferrous ion [Fe(II)] chelating. All heterofucans displayed considerable activity, especially SF-1.0v which showed the most significant antioxidant potential with 90.7 ascorbic acid equivalents in a total antioxidant capacity test and similar activity when compared with vitamin C in a reducing power assay. The fucan antiproliferative activity was performed with HeLa, PC3 and HepG2 cells using MTT test. In all tested conditions the heterofucans exhibited a dose-dependent effect. The strongest inhibition was observed in HeLa cells, where SF-1.0 and SF-1.5 exhibited considerable activity with an IC50 value of 15.69 and 13.83 µM, respectively. These results clearly indicate the beneficial effect of S. filipendula polysaccharides as antiproliferative and antioxidant. Further purification steps and additional studies on structural features as well as in vivo experiments are needed to test the viability of their use as therapeutic agents.

Heterofucans from the brown seaweed Canistrocarpus cervicornis with anticoagulant and antioxidant activities.

Fucan is a term used to denominate a family of sulfated polysaccharides rich in sulfated l-fucose. We extracted six fucans from Canistrocarpus cervicornis by proteolytic digestion followed by sequential acetone precipitation. These heterofucans are composed mainly of fucose, glucuronic acid, galactose and sulfate. No polysaccharide was capable of prolonging prothrombin time (PT) at the concentration assayed. However, all polysaccharides prolonged activated partial thromboplastin time (aPTT). Four sulfated polysaccharides (CC-0.3/CC-0.5/CC-0.7/CC-1.0) doubled aPTT with only 0.1 mg/mL of plasma, only 1.25-fold less than Clexane, a commercial low molecular weight heparin. Heterofucans exhibited total antioxidant capacity, low hydroxyl radical scavenging activity, good superoxide radical scavenging efficiency (except CC-1.0), and excellent ferrous chelating ability (except CC-0.3). These results clearly indicate the beneficial effect of C. cervicornis polysaccharides as anticoagulants and antioxidants. Further purification steps and additional studies on structural features as well as in vivo experiments are needed to test the viability of their use as therapeutic agents.