Anticancer Activity of Osthol Molecule is Mediated via Apoptosis and Autophagy Induction, G0/G1 Cell Cycle Arrest, and Downregulation of PI3K/AKT Signalling Pathway and MicroRNA 373

Liver cancer is one of the leading causes of cancer -related deaths and its incidence is increasing regularly. The currently used anticancer drugs used against liver cancer are not satisfactory and are loaded with serious side -effects. Therefore, the aim of the current study was to investigate the anticancer effects of a naturally occurring coumarin compound- osthol along with evaluating its effects on cellular apoptosis, autophagy, cell cycle and PI3K/AKT signalling pathway. WTS-1 assay was used to evaluate cell viability of Hep G2 human liver cancer cells. Apoptosis was evaluated by fluorescence microscopy using DAPI and annexin-v assay involving flow cytometry. Autophagy was evaluated by transmission electron microscopy and western blot method. Flow cytometry was used to assess effects on cell cycle while as effects on PI3K/AKT and microRNA-373 related protein expressions were examined by western blot method. Results indicated that osthol molecule led to significant and dose -dependent growth inhibitory effects on Hep G2 human liver cancer cells. Clonogenic assay showed significant decrease in Hep G2 cell colonies. DAPI and annexin v assays revealed that osthol induced significant apoptotic effects in these cells and showed dose -dependence. Electron microscopy revealed that osthol induced autophagy in Hep G2 cells by inducing autophagosomes and autophagic vacuoles. Osthol also triggered G0/G1 phase cell cycle arrest in a dose -dependent manner. Osthol also targeted PI3K/AKT signalling pathway by altering the expression of some key proteins along with up -regulating microRNA-373 expressions. In conclusion, the results indicate that osthol showed strong anticancer effects in Hep G2 human liver cancer cells by triggering apoptosis and autophagy, inducing G0/G1 cell cycle arrest, and targeting PI3K/AKT and microRNA-373 signalling pathway.