Realgar, one of
mineral drugs in Chinese traditional medicines has attracted an increasing attention because of its prominent anti-
tumor effect. However, new challenges for improving its bioavailability has to be faced. Our previous studies have demonstrated that
realgar nanoparticles may provide a less toxic agent for anti-
neoplasia by suppressing angiogenesis. In the present study, we improved milling process, prepared raw
realgar particles and
realgar nanoparticles with the same background As<inf>2</inf>O<inf>3</inf>concentrations and compared their cytoxcity to promyelocytic
leukemia HL-60 cells including inhibiting cell growth, inducing oxidative stress. It was found that treatment with
realgar nanoparticles resulted in considerably low cell viability compared with raw
realgar particles. On the other hand, treatement with
realgar nanoparticles promoted the generations of
reactive oxygen species (ROS) and inhibited the activity of
catalase (CAT), which was accompanied by lipid peroxidation and
protein oxidation, especially the loss of its free
thiols, whereas such events was not observed in HL-60 cells exposed to raw
realgar particles. These results suggest that
realgar nanoparticles are superior over raw
realgar particles for their cytotoxicity including inhibition of cell proliferation and enhanced effects of oxidative stress, which may provide a possibility for its application in
tumor therapy.