Acovenoside A Induces Mitotic Catastrophe Followed by Apoptosis in Non-Small-Cell Lung Cancer Cells.
El Gaafary M, Ezzat SM, El Sayed AM, Sabry OM, Hafner S, Lang S, Schmiech M, Syrovets T, Simmet T.
We investigated the cytotoxic potential of the cardenolide glycoside acovenoside A against non-small-cell lung cancer cells. Lung cancer is the leading cause of cancer-related mortality and the second most common cancer diagnosed. Epidemiological studies revealed a direct correlation between the regular administration of cardiac glycosides and a lower incidence of various cancers. Acovenoside A, isolated from the pericarps of Acokanthera oppositifolia, potently inhibited proliferation and induced cytotoxicity in A549 non-small-cell lung cancer cells with an IC50 of 68 ± 3 nM after 48 h of exposure. Compared to the antineoplastic agent doxorubicin, acovenoside A was more potent in inhibiting the viability of A549 cancer cells. Moreover, acovenoside A exhibited selectivity against cancer cells, being significantly less toxic to lung fibroblasts and nontoxic for peripheral blood mononuclear cells. Analysis of the cell cycle profile in acovenoside A-treated A549 cells revealed mitotic arrest, due to accumulation of the G2/M regulators cyclin B1 and CDK1, and cytokinesis failure. Furthermore, acovenoside A affected the mitochondrial membrane integrity and induced production of radical oxygen species, which resulted in induction of canonical apoptosis, manifested by caspase 3 activation and DNA fragmentation. Based on our results, acovenoside A warrants further exploration as a potential anticancer lead.