Extract of Siberian fir terpenes Abisil demonstrates antioxidant activity and induces both mitophagy and autophagy

Background. Abisil is an extract of Siberian fir terpenes with antimicrobial and wound healing activities. Previous studies revealed that Abisil has geroprotective, anti-tumorigenic and anti-angiogenic effects. Abisil decreases expression of cyclin D1, E1, A2 and increases the phosphorylation rate of AMPK.Objective. In the present study, we analyzed the effect of Abisil on mito- and autophagy, mitochondrial potential. We evaluated its antioxidant activity and analyzed transcriptomic and proteomic effect of Abisil treatment.Results. Abisil treatment resulted in 2-fold decrease of mitochondrial potential, dose-dependent increase of autophagy and mitophagy rates (up to 10-fold; MRC5/SV40 and LECH-4 cells). Abisil reverted rotenone-induced elevation of ROS levels. Surprisingly, in oxidative stress assays, lower doses of Abisil (25 mkg/ml) showed better effect than high doses (50 or 125 mkg/ml).Abisil treatment (5 and 50 mkg/ml) of MRC5/SV40 cells induced strong transcriptomic shift spanning thousand genes (predominantly, expression decrease). Among downregulated genes, we noticed over-representation of genes involved in cell cycle progression, oxidative phosphorylation and fatty acid biosynthesis. Additionally, we observed predominant downregulation of genes encoding for kinases (especially at 5 mkg/ml). Proteome profiling also revealed that the content of hundreds of proteins is altered after Abisil treatment (mainly, decreased). These proteins were involved in cell cycle regulation, intracellular transport, RNA processing, translation, mitochondrial organization. Among top altered proteins with decreased level we noticed mTOR and RICTOR.Conclusions. Abisil, an extract of Abies Sibirica resins, demonstrated antioxidant, mito- and autophagy stimulating activity. Treatment with Abisil results in predominant downregulation of genes involved in cell cycle and oxidative phosphorylation. In general, treatment in a low concentration (5 or 25 mkg/ml) in several aspects gives a better effect than treatment in high doses (50 or 125 mkg/ml).

背景：Abisil是西伯利亚冷杉萜类提取物，具备抗菌与促伤口愈合的生物活性。既往研究表明，Abisil具有延缓衰老、抗肿瘤发生及抗血管生成的效应，可下调细胞周期蛋白D1、E1、A2（cyclin D1, E1, A2）的表达，并提升腺苷酸活化蛋白激酶（AMP-activated protein kinase, AMPK）的磷酸化水平。
目的：本研究旨在分析Abisil对线粒体自噬与细胞自噬、线粒体膜电位的影响，评估其抗氧化活性，并解析Abisil处理后的转录组与蛋白质组学效应。
结果：Abisil处理可使线粒体膜电位降低2倍，并呈剂量依赖性提升细胞自噬与线粒体自噬水平（在MRC5/SV40与LECH-4细胞中最高可达10倍）。Abisil可逆转鱼藤酮诱导的活性氧（Reactive Oxygen Species, ROS）水平升高。值得注意的是，在氧化应激实验中，低剂量Abisil（25 μg/ml）的效果优于高剂量组（50或125 μg/ml）。Abisil以5 μg/ml与50 μg/ml处理MRC5/SV40细胞，可诱导涵盖数千个基因的显著转录组变化（主要表现为基因表达下调）。在下调的基因中，参与细胞周期进程、氧化磷酸化与脂肪酸生物合成的基因显著富集。此外，我们观察到编码激酶的基因整体呈现下调趋势（在5 μg/ml处理组中尤为显著）。蛋白质组分析结果同样显示，Abisil处理后数百种蛋白质的含量发生改变（主要为含量降低），这些蛋白质参与细胞周期调控、细胞内运输、RNA加工、翻译过程及线粒体组织调控。在水平下调最显著的差异蛋白质中，我们发现了mTOR与RICTOR。
结论：Abisil作为西伯利亚冷杉（Abies sibirica）树脂提取物，展现出抗氧化、刺激线粒体自噬与细胞自噬的生物活性。Abisil处理可显著下调参与细胞周期与氧化磷酸化的基因表达。总体而言，低浓度（5或25 μg/ml）的Abisil处理在多个方面的效果优于高剂量组（50或125 μg/ml）。