6-Methoxydihydrosanguinarine induces apoptosis and autophagy in breast cancer MCF-7 cells by accumulating ROS to suppress the PI3K/AKT/mTOR signaling pathway.

6-Methoxydihydrosanguinarine (6-MDS) is a natural benzophenanthridine alkaloid extracted from Hylomecon japonica (Thunb.) Prantl. It is the first time to explore the effect and mechanism of 6-MDS in breast cancer. Network pharmacology, molecular docking, and molecular dynamics simulation technology were adopted to identify the potential targets and pathways of 6-MDS in breast cancer. Besides, cell proliferation, apoptosis, and western blotting assays were conducted to investigate the effect of 6-MDS on MCF-7 cells. Network pharmacology, molecular docking, and molecular dynamics simulation results confirmed the effect of 6-MDS on resisting breast cancer via the PI3K/AKT/mTOR signaling pathway. In addition, the functional experiments results demonstrated that 6-MDS inhibited proliferation and induced apoptosis and autophagy. The autophagy inhibitor chloroquine and the silence of Atg5 augmented the effect of 6-MDS on promoting apoptosis. Furthermore, 6-MDS suppressed the PI3K/AKT/mTOR signaling pathway, and the PI3K inhibitor LY294002 enhanced these changes and promoted the 6-MDS pro-apoptotic and autophagy effects. 6-MDS triggered the generation of reactive oxygen species. The pretreatment with antioxidant N-acetyl-L-cysteine reversed the changes induced by 6-MDS, including increases in apoptosis and autophagy and inhibition of the PI3K/AKT/mTOR pathway. In conclusion, 6-MDS induces the apoptosis and autophagy of MCF-7 cells by ROS accumulation to suppress the PI3K/AKT/mTOR signaling pathway.