Department of Biotechnology, Alagappa University [Science Campus], Karaikudi, Tamil Nadu, 630 003, India.
Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA.
Pharmacol Rep. 2021 Feb;73(1):240-254. doi: 10.1007/s43440-020-00171-6. Epub 2020 Oct 23.
Thymol is a monoterpene phenol found in thyme species plants. The present study was carried out to investigate the effect of thymol and its molecular mechanism on non-small lung cancer (A549) cells.
The cytotoxic effect of thymol on A549 cells was assessed via MTT assay. ROS production, macromolecular damage, apoptosis were determined using DCF-DA, PI, AO/EtBr stains, respectively. ROS-dependent effect of thymol was confirmed using NAC. The expression of caspase-9, Bcl-2, Bax and cell cycle profile was analyzed via western blot and FACS, respectively.
The antiproliferative effect of thymol on A549 cells was found to be both dose and time dependent with IC values of 112 μg/ml (745 μM) at 24 h. Thymol treatment favored apoptotic cell death and caused G0/G1 cell cycle arrest. It mediated cellular and nuclear morphological changes, phosphatidylserine translocation, and mitochondrial membrane depolarization. Additionally, upregulation of Bax, downregulation of Bcl-2, and apoptotic fragmented DNA were also observed. Thymol induced ROS by reducing the SOD level which was confirmed via in vitro and in silico analysis. Furthermore, the levels of lipid peroxides and protein carbonyl content were elevated in thymol-treated groups. Notably, N-acetyl cysteine pretreatment reversed the efficacy of thymol on A549 cells. Moreover, thymol-treated human PBMC cells did not show any significant cytotoxicity.
Overall, our results confirmed that thymol can act as a safe and potent therapeutic agent to treat NSCLC.
百里香酚是存在于百里香属植物中的单萜酚类化合物。本研究旨在探讨百里香酚及其分子机制对非小细胞肺癌（A549）细胞的影响。
通过 MTT 法评估百里香酚对 A549 细胞的细胞毒性作用。使用 DCF-DA、PI、AO/EtBr 染色分别测定 ROS 产生、大分子损伤和细胞凋亡。使用 NAC 确认 ROS 依赖性的百里香酚作用。通过 Western blot 和 FACS 分别分析 caspase-9、Bcl-2、Bax 的表达和细胞周期谱。
发现百里香酚对 A549 细胞的增殖抑制作用呈剂量和时间依赖性，24 小时时 IC 值为 112μg/ml（745μM）。百里香酚处理有利于细胞凋亡，并导致 G0/G1 细胞周期停滞。它介导细胞和核形态变化、磷脂酰丝氨酸易位和线粒体膜去极化。此外，还观察到 Bax 的上调、Bcl-2 的下调和凋亡的碎片化 DNA。百里香酚通过降低 SOD 水平诱导 ROS，这通过体外和计算机分析得到证实。此外，百里香酚处理组的脂质过氧化物和蛋白质羰基含量升高。值得注意的是，N-乙酰半胱氨酸预处理逆转了百里香酚对 A549 细胞的功效。此外，百里香酚处理的人 PBMC 细胞没有显示出任何显著的细胞毒性。
综上所述，我们的研究结果证实百里香酚可以作为一种安全有效的治疗非小细胞肺癌的药物。
