Abstract

Abuse of new psychoactive substances is an emerging social problem. Several phenethylamines are internationally controlled substances as they are likely to be abused and have adverse effects. Phenethylamine analog 2-(4-iodo-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine (25I-NBOMe) has been reported as one of the most commonly abused psychoactive substance. However, the cardiotoxicity of this compound has not been extensively evaluated. Thus, in this study, we investigated the adverse cardiovascular effects of 25I-NBOMe, related to p21 (CDC42/RAC)-activated kinase 1 (PAK1). The cardiotoxicity of 25I-NBOMe was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, live/dead cytotoxicity assay, PAK1/CDC42 kinase assay, and in vivo electrocardiography (ECG). Also, we analyzed the expression level of PAK1, which is known to play key roles in the cardiovascular system. In the MTT assay, cell viability of 25I-NBOMe-treated H9c2 cells or primary cardiomyocytes of ICR mice decreased in a concentration-dependent manner. Results from the in vitro cytotoxicity assay in cardiomyocytes showed that 25I-NBOMe decreased the viability of H9c2 rat cardiomyocytes, and TC₅₀ of 25I-NBOMe was found to be 70.4 μM. We also observed that 25I-NBOMe reduced PAK1 activity in vitro. Surface ECG measurement revealed that intravenous injection of 25I-NBOMe (doses of 1.0 and 3.0 mg/kg, corresponding to serum concentrations of 18.1 and 28.6 ng/mL, respectively) prolonged the QTc interval in SD rats. Furthermore, treatment with 25I-NBOMe downregulated the expression of PAK1 in the hearts of SD rats and H9c2 cells. In summary, our findings indicate that PAK1-related adverse effects of 25I-NBOMe can cause toxicity to cardiomyocytes and induce an abnormal ECG pattern in animals.

摘要

滥用新的精神活性物质是一个新出现的社会问题。几种苯乙胺是国际管制物质，因为它们很可能被滥用并产生不利影响。据报道，苯乙胺类似物 2-(4-iodo-2,5-dimethoxyphenyl) -N- (2-methoxybenzyl)ethanamine (25I-NBOMe) 是最常被滥用的精神活性物质之一。然而，该化合物的心脏毒性尚未得到广泛评估。因此，在本研究中，我们调查了与 p21 (CDC42/RAC) 激活激酶 1 (PAK1) 相关的 25I-NBOMe 对心血管的不利影响。使用 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基溴化四唑 (MTT) 测定、活/死细胞毒性测定、PAK1/CDC42 激酶测定和体内评估 25I-NBOMe 的心脏毒性心电图（ECG）。此外，我们分析了已知在心血管系统中起关键作用的 PAK1 的表达水平。在 MTT 测定中，25I-NBOMe 处理的 H9c2 细胞或 ICR 小鼠的原代心肌细胞的细胞活力以浓度依赖性方式降低。心肌细胞体外细胞毒性试验结果表明，25I-NBOMe 降低了 H9c2 大鼠心肌细胞的活力，发现 25I-NBOMe 的 TC ₅₀为 70.4 μM。我们还观察到 25I-NBOMe在体外降低 PAK1 活性. 表面心电图测量显示，静脉注射 25I-NBOMe（剂量为 1.0 和 3.0 mg/kg，分别对应于 18.1 和 28.6 ng/mL 的血清浓度）延长了 SD 大鼠的 QTc 间期。此外，25I-NBOMe 治疗下调了 SD 大鼠心脏和 H9c2 细胞中 PAK1 的表达。总之，我们的研究结果表明，25I-NBOMe 的 PAK1 相关不良反应可对心肌细胞造成毒性并诱导动物心电图模式异常。