Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Integrated Pest Management on Crops in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China.
Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Integrated Pest Management on Crops in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China; Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
Pestic Biochem Physiol. 2019 Feb;154:67-77. doi: 10.1016/j.pestbp.2018.12.005. Epub 2018 Dec 18.
The β-carboline alkaloids are a large group of naturally occurring and synthetic indole alkaloids with remarkable pharmacological properties. Furthermore, these alkaloids have also been reported to be effective agents for controlling many pests and plant pathogenic nematodes. However, studies on these potential insecticidal components are scarce. The previous finding that these bioactive compounds can induce programmed cell death in cancer cell lines provided a new insight for exploration of their toxicological mechanisms on insects. In the present study, the cytotoxicity of five natural harmala alkaloids was measured, and the autophagy-inducing effect was confirmed in the Spodoptera frugiperda Sf9 cultured cell line. The results demonstrated that these alkaloids inhibited the proliferation of Sf9 cells in a dose- and time-dependent manner, and the unsaturated β-carboline alkaloids, harmine and harmol, exhibited stronger autophagy induction activity based on monodansylcadaverineand LysoTracker Red staining. Many autophagy-related genes were increased after β-carbolines treatment at the RNA level, and the protein expression of Sf-Atg8 was also confirmed to increase after treatment. In addition, the primary autophagic signaling pathway, the PI3K/Akt/mTOR pathway, was altered during the procedure. Furthermore, experiments with special inhibitors and activators were performed to confirm the effect of β-carbolines on this pathway. The results suggested that the PI3K/Akt/mTOR pathway primarily regulated harmine-induced autophagy in insect cells, and this finding may potentially benefit the application of these promising bioactivity components.
β-咔啉生物碱是一大类具有显著药理活性的天然和合成吲哚生物碱。此外，这些生物碱也被报道为控制许多害虫和植物病原线虫的有效药剂。然而，关于这些潜在杀虫成分的研究还很少。先前的研究发现，这些生物活性化合物可以诱导癌细胞系发生程序性细胞死亡，为探索其对昆虫的毒理学机制提供了新的思路。在本研究中，测定了 5 种天然骆驼蓬生物碱的细胞毒性，并在 Spodoptera frugiperda Sf9 培养细胞系中证实了其诱导自噬的作用。结果表明，这些生物碱以剂量和时间依赖的方式抑制 Sf9 细胞的增殖，不饱和β-咔啉生物碱哈尔明和哈尔醇基于单丹磺酰尸胺和 LysoTracker Red 染色显示出更强的自噬诱导活性。β-咔啉处理后，许多自噬相关基因在 RNA 水平上增加，并且处理后 Sf-Atg8 的蛋白表达也被证实增加。此外，在该过程中还改变了初级自噬信号通路，PI3K/Akt/mTOR 通路。此外，还进行了特殊抑制剂和激活剂的实验，以确认β-咔啉对该通路的影响。结果表明，PI3K/Akt/mTOR 通路主要调节昆虫细胞中哈尔明诱导的自噬，这一发现可能为这些有前途的生物活性成分的应用带来益处。
