Abstract

The evaluation of the toxicity of magnetic nanoparticles (MNPs) has attracted much
attention in recent years.  The current study aimed to investigate the cytotoxic effects
of Fe3O4, oleic acid-coated Fe3O4 (OA-Fe3O4), and carbon-coated Fe (C-Fe) nanoparticles on human hepatoma BEL-7402 cells and
the mechanisms.  WST-1 assay demonstrated that the cytotoxicity of three types of MNPs
was in a dose-dependent manner.  G1 (Fe3O4 and OA-Fe3O4) phase and G2 (C-Fe) phase cell arrests and apoptosis induced by MNPs were detected
by flow cytometry analysis.  The increase in apoptosis was accompanied with the Bax
over-expression, mitochondrial membrane potential decrease, and the release of cytochrome
C from mitochondria into cytosol.  Moreover, apoptosis was further confirmed by morphological
and biochemical hallmarks, such as swollen mitochondria with lysing cristae and caspase-3
activation.  Our results revealed that certain concentrations of the three types of
MNPs affect BEL-7402 cells viability via cell arrest and inducing apoptosis, and the
MNPs-induced apoptosis is mediated through the mitochondrial-dependent pathway.  The
influence potency of MNPs observed in all experiments would be: C-Fe > Fe3O4 > OA-Fe3O4.