Inhibition of human ovarian cancer cell lines by devil's club Oplopanax horridus

Abstract

Aim of the study: To search for more effective treatment of ovarian cancer, we investigated the in vitro anti-proliferation activities of Devil's club (OH) root bark extracts, an important medicinal plant of North America, on cisplatin sensitive and resistant human ovarian cancer cell lines.

Materials and methods: High performance liquid chromatography was used to provide the chemical profiling of the OH extracts. The anti-proliferation activities of OH extracts alone or in combination with cisplatin or paclitaxel were determined on four human ovarian cell lines by crystal violet assay. Flow cytometry and light microscopy were employed for cell cycle analysis, and also to detect apoptosis.

Results: Our data showed that water, 70% ethanol, 100% ethanol, and ethyl acetate extracts of OH inhibited the proliferation of human ovarian cancer cell lines A2780, A2780CP70, OVCAR3, and OVCAR10 in vitro. The respective 50% inhibition (IC(50)) was estimated at 1/256, 1/74, 1/69, 1/53; 1/4156, 1/1847, 1/1029, 1/4530; 1/25,753, 1/3310, 1/3462, 1/5049; and 1/29,916, 1/2912 1/3828, and 1/4232 dilutions. Some combinations of non-cytotoxic dilutions (<IC(50)) of 70% ethanol OH extract with cisplatin and paclitaxel enhanced its anti-proliferation IC(50) on A2780 and A2780CP70 cells. Cell cycle analysis demonstrated that the effect of OH extract on cell cycle was dependent on the concentration tested, blocking cells in the S and G2/M phases. At low concentrations it induced cell death by apoptosis, while at high concentrations, it kills cells by necrosis.

Conclusions: Our data showed that OH extracts exhibited significant anti-proliferation effect against both cisplatin sensitive and resistant human ovarian cell lines. Further research might result in discovery of agent(s) that can potentially be useful as an adjunct therapy for ovarian cancer cells. It is one of the few North American medicinal herbs that have been tested for anti-ovarian cancer activities.