The inhibitory effect of Osthole on A549 lung adenocarcinoma cells and its biomarker

Some natural compounds derived from medicinal plants show anti-tumor activity with high efficacy and safety, low toxicity and residual levels etc. The aim of this study was to select natural compounds and biomarkers having high inhibitory effects against A549 adenocarcinoma cells. A total of eight natural compounds having pure plant origin were initially screened, purchased, and their potential anti-cancer activities were comprehensively and systematically evaluated against A549 lung adenocarcinoma cells. The maximum non-cytotoxic concentration (MNTC) and 50% cytotoxic concentration (CC₅₀) of the eight compounds against A549 cells were obtained by cytopathological and MTT assays, respectively. Using Cisplatin as a positive control, the effect of selected compounds were elucidated on the proliferation, migration and invasion of A549 cells by MTT, wound healing and invasion assays, respectively. AnnexinV-FITC/PI, JC-1, ROS and Cell Cycle Kits were used to detect the pro-apoptotic mechanism of A549 cells induced by the tested compounds. qRT-PCR and RNA-seq were used to investigate the effective biomarkers involved in the inhibition process. The results showed that Curcumin, Osthole, Paeonol, Cepharanthine and Cisplatin significantly reduced the proliferation, migration and invasion abilities of A549 cells in a dose-dependent manner. Post 48 h of treatment, Osthole inhibited the metastatic ability of A549 cells by regulating mitochondrial apoptosis, arresting A549 cell in G1-phase and inhibiting release of ROS, while Curcumin, Paeonol and Cepharanthine did not showed the same response. It was therefore elucidated that Osthole was the optimal natural compound showing powerful anti-inhibitory properties against A549 cells. Moreover, the expressions of EGF, IL-2 and IL-10 genes were significantly decreased in Osthole treated group, while IL-6 gene was significantly increased. This study suggested that EGF gene has the potential to be used as a biomarker for Osthole treatment against A549 cells, involved in mitochondrial apoptosis and ROS down-regulation, inhibiting proliferation and epithelial mesenchymal transition (EMT), inflammation and immune processes in A549 cells providing a foundation to develop Osthole as a potential target drug to prevent the occurrence and development of lung adenocarcinoma.