Ethanol extract of Ophiorrhiza pumila suppresses liver cancer cell proliferation and migration

BACKGROUND: Ophiorrhiza pumila, belonging to the genus Ophiorrhiza (Rubiaceae), is distributed throughout tropical and subtropical Asia. In this study, we evaluated for the first time the anti-proliferation and anti-migration effects of ethanol extract of O. pumila (OPE) on HepG2 and SMMC-7721 cells, and explored the related mechanism. METHODS: OPE was prepared by percolation with 95% ethanol and its main compounds were analyzed by HPLC-MS(2). The anti-proliferation effect of OPE was evaluated by the CCK-8 assay and colony formation assay. Cell cycle distribution, apoptosis, and reactive oxygen species (ROS) level were detected by flow cytometry. Migration and invasion abilities were detected by Transwell migration/invasion assays. The expression of correlated proteins was determined using western blotting. RESULTS: A total of 5 tentative compounds were identified from OPE, including pumiloside, deoxypumiloside, camptothecin, aknadinine, and β-stigmasterol. OPE displayed strong cytostatic effects on HepG2 and SMMC-7721 cells. OPE induced G2/M phase cell cycle arrest, increased apoptosis, and augmented ROS production in these cell lines. In addition, OPE possessed a significant inhibition on cell migration and invasion by reduction of MMP-9 and MMP-2 expression. Moreover, OPE significantly suppressed the phosphorylation of p65. CONCLUSIONS: Our data showed that OPE suppresses liver cancer cell proliferation and migration, which is possibly involved with the inhibition of the NF-κB pathway.