Oxidative stress contributes to cobalt oxide nanoparticles-induced cytotoxicity and DNA damage in human hepatocarcinoma cells

Journal Article
, Saud Alarifi, Daoud Ali, Al Omar Suliman Y, Maqusood Ahamed, Maqsood A Siddiqui, Abdulaziz A Al-Khedhairy . 2013
Magazine \ Newspaper: 
Journal of International Journal of Nanomedicine - Dove Press
Volume Number: 
Publication Abstract: 

Background: Cobalt oxide nanoparticles (Co3 O4 NPs) are increasingly recognized for their utility in biological applications, magnetic resonance imaging, and drug delivery. However, little is known about the toxicity of Co3 O4 NPs in human cells. Methods: We investigated the possible mechanisms of genotoxicity induced by Co3 O4 NPs in human hepatocarcinoma (HepG2) cells. Cell viability, reactive oxygen species (ROS), glutathione, thiobarbituric acid reactive substance, apoptosis, and DNA damage were assessed in HepG2 cells after Co3 O4 NPs and Co2+ exposure. Results: Co3 O4 NPs elicited a significant (P , 0.01) reduction in glutathione with a concomitant increase in lipid hydroperoxide, ROS generation, superoxide dismutase, and catalase activity after 24- and 48-hour exposure. Co3 O4 NPs had a mild cytotoxic effect in HepG2 cells; however, it induced ROS and oxidative stress, leading to DNA damage, a probable mechanism of genotoxicity. The comet assay showed a statistically significant (P , 0.01) dose- and time-related increase in DNA damage for Co3 O4 NPs, whereas Co2+ induced less change than Co3 O4 NPs but significantly more than control. Conclusion: Our results demonstrated that Co3 O4 NPs induced cytotoxicity and genotoxicity in HepG2 cells through ROS and oxidative stress.