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-MS2. 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 beta-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-kappa B pathway.