Physiological Effects of Five Different Marine Natural Organic Matters (NOMs) and Three Different Metals (Cu, Pb, Zn) on Early Life Stages of the Blue Mussel (Mytilus galloprovincialis)

Metals are present in aquatic environments as a result of natural and anthropogenic inputs, and may induce toxicity to organisms. One of the main factors that influence this toxicity in fresh water is natural organic matter (NOM) but all NOMs are not the same in this regard. In sea water, possible protection by marine NOMs is not well understood. Thus, our study isolated marine NOMs by solid-phase extraction from five different sites and characterized them by excitation-emission fluorescence analysis—one inshore (terrigenous origin), two offshore (autochthonous origin), and two intermediate in composition (indicative of a mixed origin). The physiological effects of these five NOMS alone (at 8 mg/L), of three metals alone (copper, lead and zinc at 6 µg Cu/L, 20 µg Pb/L, and 25 µg Zn/L respectively), and of each metal in combination with each NOM, were evaluated in 48-h exposures of mussel larvae. Endpoints were whole body Ca2++Mg2+-ATPase activity, carbonic anhydrase activity and lipid peroxidation. By themselves, NOMs increased lipid peroxidation, Ca2++Mg2+-ATPase, and/or carbonic anhydrase activities (significant in seven of 15 NOM-endpoint combinations), whereas metals by themselves did not affect the first two endpoints, but Cu and Pb increased carbonic anhydrase activities. In combination, the effects of NOMs predominated, with the metal exerting no additional effect in 33 out of 45 combinations. While NOM effects varied amongst different isolates, there was no clear pattern with respect to optical or chemical properties. When NOMs were treated as a single source by data averaging, NOM had no effect on Ca2++Mg2+-ATPase activity but markedly stimulated carbonic anhydrase activity and lipid peroxidation, and there were no additional effects of any metal. Our results indicate that marine NOMs may have direct effects on this model marine organism, as well as protective effects against metal toxicity, and the quality of marine NOMs may be an important factor in these actions

Physiological effects of five different marine natural organic matters (NOMs) and three different metals (Cu, Pb, Zn) on early life stages of the blue mussel (Mytilus galloprovincialis)

Metals are present in aquatic environments as a result of natural and anthropogenic inputs, and may induce toxicity to organisms. One of the main factors that influence this toxicity in fresh water is natural organic matter (NOM) but all NOMs are not the same in this regard. In sea water, possible protection by marine NOMs is not well understood. Thus, our study isolated marine NOMs by solid-phase extraction from five different sites and characterized them by excitation-emission fluorescence analysis—one inshore (terrigenous origin), two offshore (autochthonous origin), and two intermediate in composition (indicative of a mixed origin). The physiological effects of these five NOMS alone (at 8 mg/L), of three metals alone (copper, lead and zinc at 6 µg Cu/L, 20 µg Pb/L, and 25 µg Zn/L respectively), and of each metal in combination with each NOM, were evaluated in 48-h exposures of mussel larvae. Endpoints were whole body Ca2++Mg2+-ATPase activity, carbonic anhydrase activity and lipid peroxidation. By themselves, NOMs increased lipid peroxidation, Ca2++Mg2+-ATPase, and/or carbonic anhydrase activities (significant in seven of 15 NOM-endpoint combinations), whereas metals by themselves did not affect the first two endpoints, but Cu and Pb increased carbonic anhydrase activities. In combination, the effects of NOMs predominated, with the metal exerting no additional effect in 33 out of 45 combinations. While NOM effects varied amongst different isolates, there was no clear pattern with respect to optical or chemical properties. When NOMs were treated as a single source by data averaging, NOM had no effect on Ca2++Mg2+-ATPase activity but markedly stimulated carbonic anhydrase activity and lipid peroxidation, and there were no additional effects of any metal. Our results indicate that marine NOMs may have direct effects on this model marine organism, as well as protective effects against metal toxicity, and the quality of marine NOMs may be an important factor in these actions

Piceatannol Increases Antioxidant Defense and Reduces Cell Death in Human Periodontal Ligament Fibroblast under Oxidative Stress

Piceatannol is a resveratrol metabolite that is considered a potent antioxidant and cytoprotector because of its high capacity to chelate/sequester reactive oxygen species. In pathogenesis of periodontal diseases, the imbalance of reactive oxygen species is closely related to the disorder in the cells and may cause changes in cellular metabolism and mitochondrial activity, which is implicated in oxidative stress status or even in cell death. In this way, this study aimed to evaluate piceatannol as cytoprotector in culture of human periodontal ligament fibroblasts through in vitro analyses of cell viability and oxidative stress parameters after oxidative stress induced as an injury simulator. Fibroblasts were seeded and divided into the following study groups: control, vehicle, control piceatannol, H2O2 exposure, and H2O2 exposure combined with the maintenance in piceatannol ranging from 0.1 to 20 µM. The parameters analyzed following exposure were cell viability by trypan blue exclusion test, general metabolism status by the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method, mitochondrial activity through the ATP production, total antioxidant capacity, and reduced gluthatione. Piceatannol was shown to be cytoprotective due the maintenance of cell viability between 1 and 10 µM even in the presence of H2O2. In a concentration of 0.1 µM piceatannol decreased significantly cell viability but increased cellular metabolism and antioxidant capacity of the fibroblasts. On the other hand, the fibroblasts treated with piceatannol at 1 µM presented low metabolism and antioxidant capacity. However, piceatannol did not protect cells from mitochondrial damage as measured by ATP production. In summary, piceatannol is a potent antioxidant in low concentrations with cytoprotective capacity, but it does not prevent all damage caused by hydrogen peroxide

Effects of long-term fluoride exposure are associated with oxidative biochemistry impairment and global proteomic modulation, but not genotoxicity, in parotid glands of mice

Fluoride has become widely used in dentistry because of its effectiveness in caries control. However, evidence indicates that excessive intake interferes with the metabolic processes of different tissues. Thus, this study aimed to investigate the effects of long-term exposure to F on the parotid salivary gland of mice, from the analysis of oxidative, proteomic and genotoxic parameters. The animals received deionized water containing 0, 10 or 50 mg/L of F, as sodium fluoride, for 60 days. After, parotid glands were collected for analysis of oxidative biochemistry, global proteomic profile, genotoxicity assessment and histopathological analyses. The results revealed that exposure to fluoride interfered in the biochemical homeostasis of the parotid gland, with increased levels of thiobarbituric acid reactive species and reduced glutathione in the exposed groups; as well as promoted alteration of the glandular proteomic profile in these groups, especially in structural proteins and proteins related to oxidative stress. However, genotoxic assessment demonstrated that exposure to fluoride did not interfere with DNA integrity in these concentrations and durations of exposure. Also, it was not observed histopathological alterations in parotid gland

Mecanismos de acumulação do cobre em células branquiais do marisco Mesodesma mactroides

Dissertação (mestrado)-Universidade Federal do Rio Grande, Programa de Pós-Graduação em Ciências Fisiológicas – Fisiologia Animal Comparada, Instituto de Ciências Biológicas, 2009.No presente estudo, a cinética de acumulação do cobre foi caracterizada em células branquiais isoladas do marisco Mesodesma mactroides usando duas técnicas diferentes de medida da concentração de cobre: espectrometria de absorção atômica (EAA) e fluorescência. Em uma concentração ambientalmente relevante de cobre (1 uM Cu), avaliou-se o envolvimento de diferentes mecanismos de transporte (canais de Na+, K+ e Cl-, co-transportadores Na+/K+2Cl- e Na+/Cl-, trocadores Na+/Ca2+, Cl-/HCO3- e Na+/H+) e enzimas associadas (Na+/K+-ATPase, V-ATPase e anidrase carbônica) através de diferentes ferramentas farmacológicas. Os resultados mostraram que uma cinética de acumulação do cobre do tipo saturação (mediada por transportadores) ocorre em baixas e concentrações ambientais relevantes de cobre (0-5 uM Cu), enquanto uma cinética do tipo linear (difusão) é observada em maiores concentrações de cobre (4-40 uM Cu). A toxicidade do cobre em células branquiais também é demonstrada quando ocorre uma saturação dos sítios de ligação e o influxo difusivo de cobre acontece. Além disso, as células branquiais se mostraram sensíveis aos bloqueadores dos canais de Na+ e Cl- e do trocador Na+/H+, sugerindo a importante participação destes mecanismos de transporte na regulação do volume, da concentração iônica e/ou do pH celular. Os dados do presente estudo oferecem evidências indiretas que o cobre entra nas células branquiais do marisco M. mactroides através do trocador Na+/H+, atraído pela eletronegatividade citoplasmática

Effects of sublethal Cd, Zn, and mixture exposures on antioxidant defense and oxidative stress parameters in early life stages of the purple sea urchin Strongylocentrotus purpuratus

Oxidative stress parameters were evaluated during the first 72 h of embryonic development of purple sea urchin Strongylocentrotus purpuratus continuously exposed to control conditions, to cadmium alone (Cd, 30 μg/L), to zinc alone (Zn, 9 μg/L) or to a Cd (28 μg/L) plus Zn (9 μg/L) mixture. These sublethal concentrations represent ∼ 10% of the acute EC50. Bioaccumulation, antioxidant capacity against peroxyl radicals (ACAP), total glutathione (GSH) level, glutathione-S-transferase (GST), glucose-6-phosphate dehydrogenase (G6PDH) and superoxide dismutase (SOD) activity, and lipid peroxidation (LPO) were analyzed at 24 h (blastula), 48 h (gastrula), and 72 h (pluteus) stages of development. Zinc (an essential metal) was well-regulated, whereas Cd (non-essential) bioaccumulated and whole-body [Cd] increased from blastula to pluteus stage in sea urchin larvae. In controls, ACAP progressively declined from 24 h to 72 h, while LPO reciprocally increased, but other parameters did not change. Cd alone was more potent than Zn alone as a pro-oxidant, with the major effects being decreases in SOD activity and parallel increases in LPO throughout development; GST activity also increased at 24 h. Zn alone caused only biphasic disturbances of ACAP. In all cases, the simultaneous presence of the other metal prevented the effects, and there was no instance where the oxidative stress response in the presence of the Cd/Zn mixture was greater than in the presence of either Cd or Zn alone. Therefore the sublethal effects of joint exposures were always less than additive or even protective, in agreement with classical toxicity data. Furthermore, our results indicate that SOD and Zn can play important roles in protecting sea urchin embryos against Cd-induced lipid peroxidation. © 2019 Elsevier B.V

Oxidative damage in human periodontal ligament fibroblast (hPLF) after methylmercury exposure

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001. Lygia S. Nogueira was supported by Programa Nacional de Pós-Graduação (PNPD/CAPES).Universidade Federal do Pará. Laboratório de Biologia Estrutural e Funcional. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Citogenética e Cultura de Tecidos. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Citogenética e Cultura de Tecidos. Ananindeua, PA, Brasil.Universidade Federal do Pará. Laboratório de Cultura Celular. Belém, PA, Brazil.Universidade Federal do Pará. Laboratório de Cultura Celular. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Toxicologia. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Citogenética e Cultura de Tecidos. Ananindeua, PA, Brasil / Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Belém, PA, Brazil.Universidade Federal do Pará. Laboratório de Biologia Estrutural e Funcional. Belém, PA, Brazil.Human exposure to mercury (Hg) is primary associated with its organic form, methylmercury (MeHg), through the ingestion of contaminated seafood. However, Hg contamination is also positively correlated with the number of dental restorations, total surface of amalgam, and organic mercury concentration in the saliva. Among the cells existing in the oral cavity, human periodontal ligament fibroblast (hPLF) cells are important cells responsible for the production of matrix and extracellular collagen, besides sustentation, renewal, repair, and tissue regeneration. In this way, the present study is aimed at investigating the potential oxidative effects caused by MeHg on hPLF. Firstly, we analyzed the cytotoxic effects of MeHg (general metabolism status, cell viability, and mercury accumulation) followed by the parameters related to oxidative stress (total antioxidant capacity, GSH levels, and DNA damage). Our results demonstrated that MeHg toxicity increased in accordance with the rise of MeHg concentration in the exposure solutions (1-7 μM) causing 100% of cell death at 7 μM MeHg exposure. The general metabolism status was firstly affected by 2 μM MeHg exposure (43:8±1:7%), while a significant decrease of cell viability has arisen significantly only at 3 μM MeHg exposure (68:7±1:4%). The ratio among these two analyses (named fold change) demonstrated viable hPLF with compromised cellular machinery along with the range of MeHg exposure. Subsequently, two distinct MeHg concentrations (0.3 and 3 μM) were chosen based on LC50 value (4.2 μM). hPLF exposed to these two MeHg concentrations showed an intracellular Hg accumulation as a linear-type saturation curve indicating that metal accumulated diffusively in the cells, typical for metal organic forms such as methyl. The levels of total GSH decreased 50% at exposure to 3 μM MeHg when compared to control. Finally, no alteration in the DNA integrity was observed at 0.3 μM MeHg exposure, but 3 μM MeHg caused significant damage. In conclusion, it was observed that MeHg exposure affected the general metabolism status of hPLF with no necessary decrease on the cell death. Additionally, although the oxidative imbalance in the hPLF was confirmed only at 3 μM MeHg through the increase of total GSH level and DNA damage, the lower concentration of MeHg used (0.3 μM) requires attention since the intracellular mercury accumulation may be toxic at chronic exposures

Genotoxic effect of non-lethal concentrations of minocycline in human glial cell culture

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior–Brazil (CAPES)–Finance Code 001 and supported by the Brazilian National Council for Scientific and Technological Development (CNPq).Federal University of Pará. Institute of Biological Science. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Federal University of Pará. Institute of Biological Science. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Federal University of Pará. Institute of Biological Science. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Science. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Science. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Experimental Neuroprotection and Neuroregeneration. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Science. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Minocycline has been proposed as a neuroprotective agent with pleiotropic effects on several experimental models of neurodegenerative diseases, including microglial inhibition. However, although most studies have focused on the central actions of minocycline in affecting microglial functions, other central nervous system (CNS) cell types may also be affected by this drug toxicity. Hence, considering that glial cells play a pivotal role on CNS physiology and are the main responsible for neuronal integrity, a comprehensive investigation on the effects of minocycline treatment on human glial cells is mandatory before translational studies to afford neuroprotection in humans. Therefore, we explored the cytotoxic and genotoxic effects of minocycline at different concentrations in glial cells using an in vitro model. To achieve this, U87 glial cell were exposed to 10–50 μg/mL for 24 h. After exposure, cell viability, general metabolic status and genotoxic assays were performed. No changes were observed in cell viability, however, the general metabolic status decreased over 20 μg/mL. In addition, although no chromossome aberrations were observed, evidences of genotoxicity, such as increase on micronucleus, buds and bridges, were observed from 10 μg/mL. These results suggest that minocycline may induce genotoxic effects even at concentrations considered previously safe and should be used with caution in translational studies

Non-lethal concentration of MeHg causes marked responses in the DNA repair, integrity, and replication pathways in the exposed human salivary gland cell line

Brazilian National Council for Scientific and Technological Development (CNPq); Brazilian Government/Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)-Finance Code 001 and Programa Nacional de Pós Doutorado/Capes (PNPD/CAPES). The APC was funded by Pró-Reitoria de Pesquisa e Pós-graduação da Universidade Federal do Pará (PROPESP-UFPA).Federal University of Pará. Laboratory of Functional and Structural Biology. Belém, PA, BrazilMinistério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, BrasilUniversity of São Paulo. Medical School. University Hospital of the Ribeirão Preto. Regional Blood Center. Ribeirão Preto, SP, BrazilFederal University of Pará. School of Dentistry. Belém, PA, BrazilFederal University of Pará. Laboratory of Functional and Structural Biology. Belém, PA, BrazilFederal University of Pará. School of Dentistry. Belém, PA, BrazilMinistério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, BrasilFederal University of Pará. Laboratory of Functional and Structural Biology. Belém, PA, BrazilIn Brazilian northern Amazon, communities are potentially exposed and vulnerable to methylmercury (MeHg) toxicity through the vast ingestion of fish. In vivo and in vitro studies demonstrated that the salivary glands as a susceptible organ to this potent environmental pollutant, reporting alterations on physiological, biochemical, and proteomic parameters. However, the alterations caused by MeHg on the gene expression of the exposed human salivary gland cells are still unknown. Therefore, the goal was to perform the transcriptome profile of the human salivary gland cell line after exposure to MeHg, using the microarray technique and posterior bioinformatics analysis. The cell exposure was performed using 2.5 µM MeHg. A previously published study demonstrated that this concentration belongs to a range of concentrations that caused biochemical and metabolic alterations in this linage. As a result, the MeHg exposure did not cause lethality in the human salivary gland cells line but was able to alter the expression of 155 genes. Downregulated genes (15) are entirety relating to the cell metabolism impairment, and according to KEGG analysis, they belong to the glycosphingolipid (GSL) biosynthesis pathway. On the other hand, most of the 140 upregulated genes were related to cell-cycle progression, DNA repair, and replication pathway, or cellular defenses through the GSH basal metabolism. These genomic changes revealed the effort to the cell to maintain physiological and genomic stability to avoid cell death, being in accordance with the nonlethality in the toxicity test. Last, the results support in-depth studies on nonlethal MeHg concentrations for biomarkers identification that interpret transcriptomics data in toxicological tests serving as an early alert of physiological changes in vitro biological models

Chronic Exposure to Sodium Fluoride Triggers Oxidative Biochemistry Misbalance in Mice: Effects on Peripheral Blood Circulation

The excessive fluoride (F) exposure is associated with damage to cellular processes of different tissue types, due to changes in enzymatic metabolism and breakdown of redox balance. However, few studies evaluate doses of F compatible with human consumption. Thus, this study evaluated the effects of chronic exposure to sodium fluoride (NaF) on peripheral blood of mice from the evaluation of biochemical parameters. The animals were divided into three groups (n=10) and received three concentrations of NaF in the drinking water for 60 days: 0 mg/L F, 10 mg/L F, and 50 mg/L F. The blood was then collected for trolox equivalent antioxidant capacity (TEAC), thiobarbituric acid reactive substances (TBARS), concentrations of nitric oxide (NO), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH). The results showed that doses of 10 mg/L F and 50 mg/L F were able to increase TBARS concentration and decrease NO levels and CAT activity in the blood, but there was no statistical difference for SOD levels. The 50 mg/L F group showed an increase in TEAC levels and a decrease in the GSH content when compared to the control group. In this way, oxidative changes in blood from chronic exposure to F, especially at the highest dose, indicate that F may be a toxic agent and, therefore, the long-term exposure to excessive doses should be avoided