The Anti-Tumor Effect and Underlying Apoptotic Mechanism of Ginsenoside Rk1 and Rg5 in Human Liver Cancer Cells

Ginsenoside Rk1 and Rg5 are minor ginseng saponins that have received more attention recently because of their high oral bioavailability. Each of them can effectively inhibit the survival and proliferation of human liver cancer cells, but the underlying mechanism remains largely unknown. Network pharmacology and bioinformatics analysis demonstrated that G-Rk1 and G-Rg5 yielded 142 potential targets, and shared 44 putative targets associated with hepatocellular carcinoma. Enrichment analysis of the overlapped genes showed that G-Rk1 and G-Rg5 may induce apoptosis of liver cancer cells through inhibition of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signal pathways. Methyl thiazolyl tetrazolium (MTT) assay was used to confirm the inhibition of cell viability with G-Rk1 or G-Rg5 in highly metastatic human cancer MHCC-97H cells. We evaluated the apoptosis of MHCC-97H cells by using flow cytometry and 4′,6-diamidino-2-phenylindole (DAPI) staining. The translocation of Bax/Bak led to the depolarization of mitochondrial membrane potential and release of cytochrome c and Smac. A sequential activation of caspase-9 and caspase-3 and the cleavage of poly(ADP-ribose) polymerase (PARP) were observed after that. The levels of anti-apoptotic proteins were decreased after treatment of G-Rk1 or G-Rg5 in MHCC-97H cells. Taken together, G-Rk1 and G-Rg5 promoted the endogenous apoptotic pathway in MHCC-97H cells by targeting and regulating some critical liver cancer related genes that are involved in the signal pathways associated with cell survival and proliferation.