Cytotoxic effects of Tetraselmis suecica chloroform extracts with silver nanoparticle co-application on MCF-7, 4 T1, and Vero cell lines

In the present study we evaluated the effects of silver nanoparticles (AgNPs) and Tetraselmis suecica chloroform (CHL) crude extracts as single and co-applications against MCF-7 and 4 T1 breast cancer cells and normal Vero cell-lines. The AgNPs single application exhibited the highest cytotoxicity in a dose-dependent manner with IC 50 of 5.3, 17.78, and 25.11 μg mL −1 against MCF-7, 4 T1 and Vero cell lines, respectively, after 72 h treatments. The AgNPs- T. suecica -CHL co-application at 2:1 ratio achieved the IC 50 of 6.60 and 53.7 μg mL −1 on MCF-7 and 4 T1 cells, respectively, while the T. suecica -CHL single application only showed the IC 50 of 46.77 and 83.17 μg mL −1 , respectively. However, both the T. suecica -CHL and AgNPs- T. suecica -CHL showed no cytotoxic activity against the Vero cells. The AgNPs- T. suecica -CHL exhibited the highest late apoptotic events on MCF-7 (38.8%), followed by Tamoxifen (TMX), AgNPs and T. suecica -CHL. The cell cycle analysis of AgNPs- T. suecica -CHL–treated cells showed a significant increase in the accumulation of events at sub-G1 phase with increased ADP/ATP ratio and Caspase 3/7, suggesting the induction of apoptosis. The results brought new insights into the formulation of microalgal crude extracts (MCEs) and AgNPs co-applications in exerting strong cytotoxic effects on MCF-7 and 4 T1 cancer cells, but without having any cytotoxicity on the normal Vero cell-lines.