da Silva Diana Dias, Silva Elisabete, Carmo Helena
Faculdade de Medicina, Universidade do Porto, 4200-319, Porto, Portugal; Institute for the Environment, Brunel University, Uxbridge, Middlesex, UB8 3PH, UK; REQUIMTE (Rede de Química e Tecnologia), Laboratório de Toxicologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, 4050-313, Porto, Portugal.
J Appl Toxicol. 2014 Jun;34(6):637-50. doi: 10.1002/jat.2889. Epub 2013 Jun 13.
Rise in body temperature is a life-threatening consequence of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) abuse. We evaluated the impact of hyperthermia on the cytotoxicity of combinations of MDMA and three other amphetamines, often co-ingested. For this, Hep G2 cells were exposed to MDMA, d-amphetamine, methamphetamine and 4-methylthioamphetamine, individually or combined, at 40.5 °C. The results were compared with normothermia data (37.0 °C). Mixture additivity expectations were calculated by independent action and concentration addition (CA) models. To delineate the mechanism(s) underlying the elicited effects, a range of stress endpoints was evaluated, including quantification of reactive oxygen/nitrogen species (ROS/RNS), lipid peroxidation, reduced/oxidized glutathione (GSH/GSSG), ATP and mitochondrial membrane potential (Δψm) changes. Our data show that, in hyperthermia, amphetamines acted additively and mixture effects were accurately predicted by CA. At 40.5 °C, even slight increases in the concentrations of each drug/mixture promoted significant rises in cytotoxicity, which quickly shifted from roughly undetectable to maximal mortality. Additionally, the increase of RNS/ROS production, decrease of GSH, ATP depletion and mitochondrial impairment were exacerbated under hyperthermia. Importantly, when equieffective cytotoxic concentrations of the mixture and individual amphetamines were compared for all tested stress endpoints, mixture effects did not deviate from those elicited by individual treatments, suggesting that these amphetamines have a similar mode of action, which is not altered in combination. Concluding, our data indicate that amphetamine mixtures produce deleterious effects, even when individual drugs are combined at negligible concentrations. These effects are strongly exacerbated in hyperthermia, emphasizing the potential increased risks of ecstasy intake, especially when hyperthermia occurs concurrently with polydrug abuse.
体温升高是3,4-亚甲基二氧甲基苯丙胺（摇头丸）滥用危及生命的后果。我们评估了体温过高对摇头丸与其他三种经常同时摄入的苯丙胺类药物组合的细胞毒性的影响。为此，将肝癌细胞系Hep G2细胞在40.5℃下单独或联合暴露于摇头丸、右旋苯丙胺、甲基苯丙胺和4-甲硫基苯丙胺。将结果与正常体温数据（37.0℃）进行比较。通过独立作用和浓度相加（CA）模型计算混合物相加性预期值。为了阐明所引发效应的潜在机制，评估了一系列应激终点，包括活性氧/氮物质（ROS/RNS）的定量、脂质过氧化、还原型/氧化型谷胱甘肽（GSH/GSSG）、三磷酸腺苷（ATP）以及线粒体膜电位（Δψm）变化。我们的数据表明，在体温过高情况下，苯丙胺类药物呈相加作用，且CA模型能准确预测混合物效应。在40.5℃时，即使每种药物/混合物的浓度略有增加也会导致细胞毒性显著升高，细胞毒性很快从几乎不可检测转变为最大死亡率。此外，在体温过高情况下，RNS/ROS生成增加、GSH减少、ATP耗竭以及线粒体损伤加剧。重要的是，当比较混合物和各单独苯丙胺类药物在所有测试应激终点的等效细胞毒性浓度时，混合物效应与单独处理所引发的效应并无偏差，这表明这些苯丙胺类药物具有相似的作用模式，联合使用时不会改变。总之，我们的数据表明，即使各单独药物以可忽略不计的浓度联合使用，苯丙胺类药物混合物也会产生有害影响。在体温过高情况下，这些影响会强烈加剧，这突出了服用摇头丸潜在增加的风险，尤其是当体温过高与多药滥用同时发生时。
