Aconitine is one of the main bioactive and toxic ingredients of Aconitum species. Increasingly, aconitine has been reported to induce neurotoxicity. However, whether aconitine has effects on the dopaminergic nervous system remains unclear. In this study, zebrafish embryos at 6-days postfertilization were exposed to aconitine at doses of 0.5, 1, and 2 μM for 24 h, and SH-SY5Y cells were treated with 50, 100, and 200 μM of aconitine for 24 h. Results demonstrated that aconitine treatment induced deformities and enhanced the swimming behavior of zebrafish larvaes. Aconitine exposure suppressed cell proliferation and increased the number of reactive oxygen species and apoptosis in zebrafish larvaes and SH-SY5Y cells. Aconitine altered the levels of dopamine and its metabolites by regulating the expression of genes and proteins related to dopamine synthesis, storage, degradation, and reuptake in vivo and in vitro. Moreover, aconitine activated the AC/cAMP/PKA pathway by activating the dopamine D1 receptor (D1R) and inhibiting the dopamine D2 receptor (D2R) to disturb intracellular calcium homeostasis, eventually leading to the damage of nerve cells. Furthermore, the D1R antagonist SCH23390 and D2R agonist sumanirole pretreatment effectively attenuated the excitatory state of larvaes. Sumanirole and PKA antagonist H-89 pretreatment effectively decreased intracellular Ca2+ accumulation induced by aconitine in vivo. SCH23390 and sumanirole also reduced aconitine-induced cytotoxicity by inhibiting the AC/cAMP/PKA pathway in vitro. These results suggested that dopamine homeostasis imbalance and dopamine receptors (DRs)-mediated AC/cAMP/PKA pathway activation might be vital mechanisms underlying aconitine-induced neurological injury.

中文翻译：

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多巴胺稳态失衡和多巴胺受体介导的 AC/cAMP/PKA 通路激活与乌头碱诱导的斑马鱼和 SH-SY5Y 细胞神经损伤有关。

乌头碱是乌头属的主要生物活性和毒性成分之一。越来越多的报道称乌头碱会引起神经毒性。然而，乌头碱是否对多巴胺能神经系统有影响仍不清楚。在这项研究中，将受精后 6 天的斑马鱼胚胎以 0.5、1 和 2 μM 的剂量暴露于乌头碱 24 小时，并用 50、100 和 200 μM 的乌头碱处理 SH-SY5Y 细胞 24 小时。结果表明，乌头碱处理会引起畸形并增强斑马鱼幼虫的游泳行为。乌头碱暴露抑制细胞增殖并增加斑马鱼幼虫和 SH-SY5Y 细胞中活性氧和细胞凋亡的数量。乌头碱通过调节与体内和体外多巴胺合成、储存、降解和再摄取相关的基因和蛋白质的表达来改变多巴胺及其代谢物的水平。此外，乌头碱通过激活多巴胺 D1 受体 (D1R) 和抑制多巴胺 D2 受体 (D2R) 来扰乱细胞内钙稳态，从而激活 AC/cAMP/PKA 通路，最终导致神经细胞的损伤。此外，D1R 拮抗剂 SCH23390 和 D2R 激动剂 sumaniro 预处理有效地减弱了幼虫的兴奋状态。Sumanirole 和 PKA 拮抗剂 H-89 预处理有效地减少了体内乌头碱诱导的细胞内 Ca2+ 积累。SCH23390 和 sumaniro 还通过在体外抑制 AC/cAMP/PKA 通路来降低乌头碱诱导的细胞毒性。