Anthraquinones from the roots of Morinda scabrida Craib exhibit antiproliferative activity against A549 lung cancer cells and antitubulin polymerization.

Six anthraquinones were isolated from Morinda scabrida Craib, an unexplored species of Morinda found in the tropical forest of Thailand. All six anthraquinones showed cytotoxicity against A549 lung cancer cells, with the most active compound, nordamnacanthal (MS01), exhibiting the IC 50 value of 16.3 ± 2.5 μM. The cytotoxic effect was dose-dependent and led to cell morphological changes characteristic of apoptosis. In addition, flow cytometric analysis showed dose-dependent apoptosis induction and the G2/M phase cell cycle arrest, which was in agreement with the tubulin polymerization inhibitory activity of MS01. Molecular docking analysis illustrated the binding between MS01 and the α/β-tubulin heterodimer at the colchicine binding site, and UV–visible absorption spectroscopy revealed the DNA binding capacity of MS01. [Display omitted] • Six anthraquinones were isolated from Morinda scabrida Craib, an unexplored species. • Nordamnacanthal exhibited the IC 50 value of 16.3 ± 2.5 μM against A549 lung cancer cells. • Apoptosis and the G2/M phase cell cycle arrest were induced by nordamnacanthal. • Antitubulin activity supported the cell cycle arrest activity of nordamnacanthal. [ABSTRACT FROM AUTHOR]