Cytotoxic effect of magnetic iron oxide nanoparticles synthesized via seaweed aqueous extract

Magnetic iron oxide nanoparticles (Fe3O4MNPs) are among the most useful metalnanoparticles for multiple applications across a broad spectrum in the biomedical field, includ-ing the diagnosis and treatment of cancer. In previous work, we synthesized and characterizedFe3O4MNPs using a simple, rapid, safe, efficient, one-step green method involving reduction offerric chloride solution using brown seaweed (Sargassum muticum) aqueous extract containinghydroxyl, carboxyl, and amino functional groups mainly relevant to polysaccharides, which actsas a potential stabilizer and metal reductant agent. The aim of this study was to evaluate the invitro cytotoxic activity and cellular effects of these Fe3O4MNPs. Their in vitro anticancer activitywas demonstrated in human cell lines for leukemia (Jurkat cells), breast cancer (MCF-7cells),cervical cancer (HeLa cells), and liver cancer (HepG2cells). The cancer cells were treated withdifferent concentrations of Fe3O4MNPs, and an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide) assay was used to test for cytotoxicity, resulting in an inhibitory concentra-tion 50 (IC50)value of 23.83±1.1μg/mL (HepG2), 18.75±2.1μg/mL (MCF-7), 12.5±1.7μg/mL(HeLa), and 6.4±2.3μg/mL (Jurkat) 72hours after treatment. Therefore, Jurkat cells were selectedfor further investigation. The representative dot plots from flow cytometric analysis of apoptosisshowed that the percentages of cells in early apoptosis and late apoptosis were increased. Cellcycle analysis showed a significant increase in accumulation of Fe3O4MNP-treated cells atsub-G1phase, confirming induction of apoptosis by Fe3O4MNPs. The Fe3O4MNPs also activatedcaspase-3and caspase-9in a time-response fashion. The nature of the biosynthesis and thera-peutic potential of Fe3O4MNPs could pave the way for further research on the green synthesisof therapeutic agents, particularly in nanomedicine, to assist in the treatment of cancer.