title: In vitro neurotoxicity evaluation of piperazine designer drugs in differentiated human neuroblastoma SH-SY5Y cells.
abstract: 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.
authors.affiliation: REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: M D
authors.initials: MD
authors.lastname: Arbo
authors.affiliation: REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: R
authors.initials: R
authors.lastname: Silva
authors.affiliation: REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.|Cell Division Mechanisms Group, Institute for Molecular and Cell Biology - IBMC, Porto, Portugal.
authors.forename: D J
authors.initials: DJ
authors.lastname: Barbosa
authors.affiliation: REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: D
authors.initials: D
authors.lastname: Dias da Silva
authors.affiliation: Instituto Nacional de Saúde Dr. Ricardo Jorge (INSA), Porto, Portugal.
authors.forename: S P
authors.initials: SP
authors.lastname: Silva
authors.affiliation: Instituto Nacional de Saúde Dr. Ricardo Jorge (INSA), Porto, Portugal.
authors.forename: J P
authors.initials: JP
authors.lastname: Teixeira
authors.affiliation: REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: M L
authors.initials: ML
authors.lastname: Bastos
authors.affiliation: REQUIMTE, Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: H
authors.initials: H
authors.lastname: Carmo
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D015198:Designer Drugs / Q000633:toxicity*; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects; D009447:Neuroblastoma / Q000473:pathology; D020258:Neurotoxicity Syndromes / Q000209:etiology*; D000077489:Piperazine; D010879:Piperazines / Q000633:toxicity*
chemical_list: D015198:Designer Drugs; D010879:Piperazines; D000077489:Piperazine; D005978:Glutathione; D002118:Calcium
keywords: Ca2+ overload; apoptosis; cytotoxicity; mitochondrial hyperpolarization; piperazine designer drugs