Inhibition Effect of Walnut Leaf Polysaccharide on HepG2 Cells in vitro

In this study, the effect of Walnut Leaf Polysaccharides (WLP) on human liver tumor HepG2 cells was investigated. The results showed that WLP had dose-dependent and time-dependent inhibitory effects on HepG2 cell viability. Typical apoptosis characteristics were observed in WLP-treated HepG2 cells through 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-benzimidazolyl-carbocyanine iodide (DAPI) staining and Acridine Orange (AO)/Ethidium Bromide (EB) dual staining. Meanwhile, significant decrease in Mitochondrial Membrane Potential (MMP) and increase in intracellular Reactive Oxygen Species (ROS) levels of WLP-induced HepG2 cells were detected by 5,5',6,6'-Tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1) and 2',7'-Dichlorodihydrofluorescein Diacetate (DCFH-DA) fluorescent probes, respectively. Moreover, cell viability, MMP and ROS level of HepG2 cells were observed after intervention with antioxidant NAC. Thus, we speculated that WLP may induce apoptosis of HepG2 cells by decreasing MMP and increasing intracellular ROS levels. The results suggest that WLP could be developed as a promising natural anticancer active substance in the pharmaceutical and functional food industries.