The In Vitro Anti-Cancer Activities of 17βH-Neriifolin Isolated from Cerbera odollam and Its Binding Activity on Na+,K+-ATPase.

17βH-neriifolin, a cardiac glycoside compound had been successfully isolated from Cerbera odollam leaves based on bioassay guided isolation procedure. The compound was tested against breast (MCF-7, T47D), colorectal (HT-29), ovarian (A2780, SKOV-3) and skin (A375) cancer cell lines that gave IC50 values ranged from 0.022 ± 0.0015 to 0.030 ± 0.0018 µM. The mechanism of cell death of 17βH-neriifolin was further evaluated using Hoescht 33342 assay and it was found that the compound killed the cancer cells via apoptosis in dose dependent manner. In silico molecular docking studies and in vitro malachite green assay were used to predict the binding activities of 17βH-neriifolin on Na+,K+-ATPase and ouabain was also included as for comparison studies. 17βH-neriifolin and ouabain both bind at α-subunit in Na+,K+-ATPase and their binding energy were -8.16 ± 0.74 kcal/mol and -8.18 ± 0.48 kcal/mol respectively.