Lily Polysaccharide Nano-Selenium Promotes A549 Cells Apoptosis through Cell Cycle Inhibition

This study uses Lilium davidii var. unicolor (Lanzhou lily) polysaccharides extracted from bulbs to prepare nano-selenium (nano-Se) polysaccharide (LPS). Here, the study explores the molecular structure characterization, inhibition effects, and mechanisms of action of prepared LPS on A549 lung cancer cells. The LPS structure is characterized using Fourier-transform infrared spectroscopy (FTIR), UV spectroscopy (UV–vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), etc. Results show that selenized polysaccharides bonded through electrostatic adsorption, with an average LPS particle size of 243.75 nm and zeta potential of −38.3 mV, which can be stably preserved at 4 °C for more than 3 months. The in vitro antitumor activity experiment shows that the prepared LPS inhibited A549 cell proliferation while affecting cell migration. Cell cycle analysis shows that apoptosis is promoted by blocking the G1 phase, while during the late apoptosis stage cells accounted for 60%. RNA-Seq data analysis shows that the main mechanisms of action on A549 cells are to inhibit DNA replication initiation genes, block the cell cycle, and regulate the expression of apoptosis-related genes and proteins in promoting cell apoptosis.