Mangroves perform essential functions in biological cycles and are protected by law in Brazil. However, they are being degraded above their support limit, leading to a reduction in the areas around the world. The area...Mangroves perform essential functions in biological cycles and are protected by law in Brazil. However, they are being degraded above their support limit, leading to a reduction in the areas around the world. The area investigated in the present study is a potentially unpolluted mangrove ecosystem in the south of Rio de Janeiro state, Brazil. The aim of this work was to investigate the presence of metals and polycyclic aromatic hydrocarbons (PAHs) in mangrove sediment and to correlate them with mutagenic and genotoxic activity. Four seasonal samplings undertaken between 2009 and 2010 at five sites were analyzed. Dichloromethane extracts were obtained under sonication and subjected to mutagenicity assays using Salmonella microsuspension. Metal (Cd, Cr, Cu, Ni and Pb) contents were determined by atomic absorption spectrometry, while the quantification of PAHs was performed by gas chromatography-mass spectrometry. Goniopsis cruentata hemocytes were used to assess potential genotoxic damage (Micronucleus assay). The absence of mutagenicity was observed for all samples using Salmonella typhimurium strains TA97, TA98, TA100 and TA102, in the absence and presence of an exogenous mammalian metabolizing system. Among the metals, Cd and Cu were detected in autumn at values exceeding the threshold effect level and below the probable effect level. Benzo[a] pyrene was detected at levels above the threshold at one site, where small effects could be observed in the biota. Significant differences in the micronucleated cells observed suggest DNA damage had been induced by the PAHs identified.展开更多
Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory dis-turbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are...Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory dis-turbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with techne-tium-99m (99mTc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with 99mTc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with 99mTc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with 99mTc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with 99mTc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract.展开更多
基金the Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro(FAPERJ),Coordination for the improvement of Higher Education Personnel(Capes)and National Council of Technological and Scientific Development(CNPq)for fellowships and financial support.
文摘Mangroves perform essential functions in biological cycles and are protected by law in Brazil. However, they are being degraded above their support limit, leading to a reduction in the areas around the world. The area investigated in the present study is a potentially unpolluted mangrove ecosystem in the south of Rio de Janeiro state, Brazil. The aim of this work was to investigate the presence of metals and polycyclic aromatic hydrocarbons (PAHs) in mangrove sediment and to correlate them with mutagenic and genotoxic activity. Four seasonal samplings undertaken between 2009 and 2010 at five sites were analyzed. Dichloromethane extracts were obtained under sonication and subjected to mutagenicity assays using Salmonella microsuspension. Metal (Cd, Cr, Cu, Ni and Pb) contents were determined by atomic absorption spectrometry, while the quantification of PAHs was performed by gas chromatography-mass spectrometry. Goniopsis cruentata hemocytes were used to assess potential genotoxic damage (Micronucleus assay). The absence of mutagenicity was observed for all samples using Salmonella typhimurium strains TA97, TA98, TA100 and TA102, in the absence and presence of an exogenous mammalian metabolizing system. Among the metals, Cd and Cu were detected in autumn at values exceeding the threshold effect level and below the probable effect level. Benzo[a] pyrene was detected at levels above the threshold at one site, where small effects could be observed in the biota. Significant differences in the micronucleated cells observed suggest DNA damage had been induced by the PAHs identified.
基金Project supported by CAPES, CNPq and FAPERJ, Brazil
文摘Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory dis-turbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with techne-tium-99m (99mTc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with 99mTc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with 99mTc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with 99mTc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with 99mTc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract.
