Acute toxicity and environmental risk of teflubenzuron to Daphnia magna, Poecilia reticulata and Lemna minor in the absence and presence of sediment

This study aimed to estimate the acute toxicity of teflubenzuron (1-(3,5-dichloro-2,4-difluorophenyl)-3-(2,6-difluorobenzoyl)urea) (TFB) for Daphnia magna, Lemna minor and Poecilia reticulata, in the absence and presence of sediment; evaluate the effect of sediment on the TFB bioavailability; and to classify this insecticide according to its environmental poisoning risk for agricultural and aquaculture uses. The tests of TFB acute toxicity were conducted in static system in a completely randomized design with increasing TFB concentrations, and a control group. The TFB has been classified according to the estimated values of EC50 and LC50 by its acute toxicity and environmental risk. The sediment significantly reduced toxicity and bioavailability of TFB in water column. Therefore, the insecticide can be classified as being highly toxic to Daphnia magna, which means the agricultural and aquacultural uses of TFB pose a high risk of environmental toxicity to non-target organisms. However, it was practically non-toxic to L. minor and P. reticulata. © 2013 Copyright Taylor and Francis Group, LLC.

Toxicity of hydramethylnon to the leaf-cutting ant Atta sexdens rubropilosa forel (hymenoptera: Formicidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

PLA and Montmorilonite Nanocomposites: Properties, Biodegradation and Potential Toxicity

The concern related to solid waste increases efforts to develop products based on biodegradable materials. At present, PLA has one of the highest potentials among biopolyesters, particularly for packaging. However, its application is limited in some fields. In order to optimize PLA properties, organo-modified montmorilonites have been extensively used to obtain nanocomposites. Although PLA nanocomposites studies are widely reported in the literature, there is still few information about the influence of organoclays on de biodegradation process, which is a relevant information, since one of the main purposals related to the final disposal of biopolymers as PLA is composting. Besides, in the last years some research has been conducted in order to evaluate the potential toxicity of montmorilonite, unmodified or organo-modified. Since the use of montmorilonite is expanding in different applications, human exposure and risk assessment are important issues to be investigated. In this context, this review intends to compile available information related to common organoclays used for PLA nanocomposites, its properties, biodegradation analysis and potential toxicity evaluation of nanocomposites, focused on montmorilonite as filler. Two issues of relevance were pointed out. The first is food safety and quality, and the second consideration is the environmental effect. © 2013 Springer Science+Business Media New York.

Biochemical responses in armored catfish (Pterygoplichthys anisitsi) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends

Biodiesel fuel is gradually replacing petroleum-based diesel oil use. Despite the biodiesel being considered friendlier to the environment, little is known about its effects in aquatic organisms. In this work we evaluated whether biodiesel exposure can affect oxidative stress parameters and biotransformation enzymes in armored catfish (Pterygoplichthys anisitsi, Loricariidae), a South American endemic species. Thus, fish were exposed for 2 and 7d to 0.01mLL-1 and 0.1mLL-1 of pure diesel, pure biodiesel (B100) and blends of diesel with 5% (B5) and 20% (B20) biodiesel. Lipid peroxidation (malondialdehyde) levels and the activities of the enzymes glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were measured in liver and gills. Also, DNA damage (8-oxo-7, 8-dihydro-2'-deoxyguanosine) levels in gills and 7-ethoxyresorufin-O-deethylase activity in liver were assessed. Pure diesel, B5 and B20 blends changed most of the enzymes tested and in some cases, B5 and B20 induced a higher enzyme activity than pure diesel. Antioxidant system activation in P. anisitsi was effective to counteract reactive oxygen species effects, since DNA damage and lipid peroxidation levels were maintained at basal levels after all treatments. However, fish gills exposed to B20 and B100 presented increased lipid peroxidation. Despite biodiesel being more biodegradable fuel that emits less greenhouse gases, the increased lipid peroxidation showed that biofuel and its blends also represent hazards to aquatic biota. © 2013 Elsevier Ltd.

Aquatic Exercise is as Effective as dry Land Training to Blood Pressure Reduction in Postmenopausal Hypertensive Women

Background and Purpose: The evidence of the benefits from regular physical activity to hypertensives is based on dry land training studies. Therefore, the aim of this study is to compare the effect of aquatic exercise with dry land training on hypertensive women. Methods: This is a randomized controlled study with 52 post-menopausal hypertensive women. The patients were randomly allocated in three groups: water aerobic training group (n=19), dry land aerobic training group (n=19) and a non-intervention control group (n=14). The training protocol was performed by 12weeks. Results: There were no differences among the three groups concerning basal blood pressure (BP) and biochemical variables. In water group, there was a statistically significant reduction of systolic BP from 136±16mmHg at zero week to 124±18mm Hg at 11th week and 124±15mmHg at 12th week. In dry land training group, there was a statistically significant reduction of systolic BP from 138±15mmHg at zero week to 125±10mmHg at 7th week, 127±10mmHg at 10th week and 126±9mmHg at 12th week. The control group presented no change in any of the assessed variables. No changes were carried out in any antihypertensive medications during study. Discussion: This is a randomized controlled study that demonstrates the antihypertensive efficacy of aerobic aquatic exercise. © 2013 John Wiley & Sons, Ltd.

In vivo analgesic activity, toxicity and phytochemical screening of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine

Ethnopharmacological relevance: Psidium cattleianum Sabine is extensively used in Brazilian traditional medicine to treat several diseases including painful disorders. Aim of the study to investigate the toxicity and the possible analgesic activities of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine (ELPCS), to support its use in folk medicine. To screen the major phytochemical constituents of this extract and evaluate their antioxidant activity. Materials and methods: ELPCS was assessed for its antioxidant activity using the DPPH model. Its analgesic activity was examined using mouse models of acetic acid-induced writhing and hot plate paw licking models. The major phytochemical constituents of the extract were screened; their toxicity on LLC-MK2 mammalian cells was evaluated. Results: ELPCS exhibited significant peripheral analgesic activity at doses of 60, 80, 100, 200 and 400 mg/kg in mice, but it did not display central analgesic activity and not was toxic to LLC-MK2 cell (LD 50>400 μg/mL). The extract exhibited free radical scavenging activity as evidenced by IC 50 values (15.9 μg/mL) obtained by the DPPH method. Phytochemical screening detected flavonoids, saponins, cardiac glycosides, anthraquinones, and tannins. Conclusions: The results of the experimental studies proved the analgesic activity of ELPCS and supported the traditional use of this plant. © 2013 Elsevier B.V. All rights reserved.

Fish exposure to nano-TiO2 under different experimental conditions: Methodological aspects for nanoecotoxicology investigations

The ecotoxicology of nano-TiO2 has been extensively studied in recent years; however, few toxicological investigations have considered the photocatalytic properties of the substance, which can increase its toxicity to aquatic biota. The aim of this work was to evaluate the effects on fish exposed to different nano-TiO2 concentrations and illumination conditions. The interaction of these variables was investigated by observing the survival of the organisms, together with biomarkers of biochemical and genetic alterations. Fish (Piaractus mesopotamicus) were exposed for 96h to 0, 1, 10, and 100mg/L of nano-TiO2, under visible light, and visible light with ultraviolet (UV) light (22.47J/cm2/h). The following biomarkers of oxidative stress were monitored in the liver: concentrations of lipid hydroperoxide and carbonylated protein, and specific activities of superoxide dismutase, catalase, and glutathione S-transferase. Other biomarkers of physiological function were also studied: the specific activities of acid phosphatase and Na,K-ATPase were analyzed in the liver and brain, respectively, and the concentration of metallothionein was measured in the gills. In addition, micronucleus and comet assays were performed with blood as genotoxic biomarkers. Nano-TiO2 caused no mortality under any of the conditions tested, but induced sublethal effects that were influenced by illumination condition. Under both illumination conditions tested, exposure to 100mg/L showed an inhibition of acid phosphatase activity. Under visible light, there was an increase in metallothionein level in fish exposed to 1mg/L of nano-TiO2. Under UV light, protein carbonylation was reduced in groups exposed to 1 and 10mg/L, while nucleus alterations in erythrocytes were higher in fish exposed to 10mg/L. As well as improving the understanding of nano-TiO2 toxicity, the findings demonstrated the importance of considering the experimental conditions in nanoecotoxicological tests. This work provides information for the development of protocols to study substances whose toxicity is affected by illumination conditions. © 2013 Elsevier B.V..

Avaliação ecotoxicológica e risco ambiental dos inseticidas utilizados no controle da larva de Aedes aegypti para Daphnia magna, Lemna minor e peixes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Toxicidade aguda e risco ambiental do diflubenzuron para Daphnia magna, Poecilia reticulata e Lemna minor na ausência e presença de sedimento

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Toxidade aguda e risco ambiental do inseticida teflubenzuron para Daphnia magna, Lemna minor e Poecilia reticulata

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Toxicidade aguda e risco ecotoxicológico do fipronil para o guarú (Poecilia reticulata) e dissipação no ambiente aquático

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Degradação fotocatalítica de efluente simulado de refinaria de petróleo e monitoramento de sua toxicidade com microrganismos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Biomarcadores bioquímicos de contaminação em girinos de anfíbios anuros expostos a Regent®800WG (Fipronil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de biomarcadores bioquímicos em tilápias (Oreochromis niloticus) expostos a óleo diesel e biodiesel

Pós-graduação em Química - IBILCE

Aspectos ecotoxicológicos dos inseticidas diflubenzuron e teflubenzuron para o pacú (Piaractus mesopotamicus)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)