Clycosmis parva is a small shrub found in Thailand. Ethyl acetate (EtOAc) extract from its leaves has been shown to exert anticancer effects in vitro; however, the compound responsible for this activity has not been isolated and characterized In this study, we demonstrate that arborinine, a major acridone alkaloid in the EtOAc fraction, decreased proliferation and was strongly cytotoxic to HeLa cervical cancer cells without significantly affecting normal cells. The compound also inhibited tumor spheroid growth much more potently than chemotherapeutic drugs bleomycin, gemcitabine, and cisplatin. In addition, unlike cisplatin, arborinine activated caspase-dependent apoptosis without inducing DNA damage response. We further show that arborinine strongly suppressed cancer cell migration by downregulating expression of key regulators of epithelial-mesenchymal transition. Taken together, our data provide important insights into the molecular mechanism of arborinine's anticancer activity, supporting its potential use for treating cervical cancer. (C) 2018 Elsevier Inc. All rights reserved.