Percorrer por autor "Silva, S.P."
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- In vitro neurotoxicity evaluation of piperazine designer drugs in differentiated human neuroblastoma SH-SY5Y cellsPublication . Arbo, M.D.; Silva, R.; Barbosa, D.J.; da Silva, D. Dias; Silva, S.P.; Teixeira, João Paulo; Bastos, M.L.; Carmo, H.Abuse of synthetic drugs is widespread worldwide. Studies indicate that piperazine designer drugs act as substrates at dopaminergic and serotonergic receptors and/or transporters in the brain. This work aimed to investigate the cytotoxicity of N-benzylpiperazine, 1-(3-trifluoromethylphenyl)piperazine, 1-(4-methoxyphenyl)piperazine and 1-(3,4-methylenedioxybenzyl)piperazine in the differentiated human neuroblastoma SH-SY5Y cell line. Cytotoxicity was evaluated after 24 h incubations through the MTT reduction and neutral red uptake assays. Oxidative stress (reactive oxygen and nitrogen species production and glutathione content) and energetic (ATP content) parameters, as well as intracellular Ca(2+) , mitochondrial membrane potential, DNA damage (comet assay) and cell death mode were also evaluated. Complete cytotoxicity curves were obtained after 24 h incubations with each drug. A significant decrease in intracellular total glutathione content was noted for all the tested drugs. All drugs caused a significant increase of intracellular free Ca(2+) levels, accompanied by mitochondrial hyperpolarization. However, ATP levels remained unchanged. The investigation of cell death mode revealed a predominance of early apoptotic cells. No genotoxicity was found in the comet assay. Among the tested drugs, 1-(3-trifluoromethylphenyl)piperazine was the most cytotoxic. Overall, piperazine designer drugs are potentially neurotoxic, supporting concerns on risks associated with the abuse of these drugs. Copyright © 2015 John Wiley & Sons, Ltd.
- Removal of polycyclic aromatic hydrocarbons by biosorbentsPublication . José, Sílvia S.; Cardoso, A.S.; Silva, S.P.; Mestre, A.S; Carvalho, A.P.Introduction: - Polycyclic aromatic hydrocarbons (PAHs) are a group of environmental carcinogens. They are formed during the incomplete combustion of organic matter. Humans are exposed to PAHs by various sources, including occupational environments, cigarette smoke, vehicle exhaust, and dietary sources as grilled and flame-broiled food. - In vivo studies in animals proved that PAHs are associated to cancer, and epidemiologic studies with exposed workers, especially in coke ovens and aluminium smelters, have shown clear excess of lung cancer and highly suggestive excesses of bladder cancer. - These compounds can enter in drinking water sources by precipitation and runoff on the earth’s surface. - Portuguese legislation for water for human consumption (DL 306/2007) proposes the determination of five PAHs; limits of the maximum concentration are 0.10 µg/L for total BghiP, BbF, BkF, IcdP, and 0.010 µg/L for BaP.