Back to Journals » International Journal of Nanomedicine » Volume 8 » Issue 1

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

Authors Alarifi S, Ali D, Suliman Y AO, Ahamed M, Siddiqui MA, Al-Khedhairy AA

Received 10 September 2012

Accepted for publication 4 October 2012

Published 8 January 2013 Volume 2013:8(1) Pages 189—199


Checked for plagiarism Yes

Review by Single-blind

Peer reviewer comments 3

Saud Alarifi,1 Daoud Ali,1 Al Omar Suliman Y,2 Maqusood Ahamed,3 Maqsood A Siddiqui,2 Abdulaziz A Al-Khedhairy2

Cell and Molecular Laboratory, Department of Zoology, Faculty of Science, King Saud University, Riyadh, Saudi Arabia; 2Faculty of Science, Department of Zoology, King Saud University, Riyadh, Saudi Arabia; 3King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, Saudi Arabia

Background: Cobalt oxide nanoparticles (Co3O4NPs) are increasingly recognized for their utility in biological applications, magnetic resonance imaging, and drug delivery. However, little is known about the toxicity of Co3O4NPs in human cells.
Methods: We investigated the possible mechanisms of genotoxicity induced by Co3O4NPs 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 Co3O4NPs and Co2+ exposure.
Results: Co3O4NPs 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. Co3O4NPs 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 Co3O4NPs, whereas Co2+ induced less change than Co3O4NPs but significantly more than control.
Conclusion: Our results demonstrated that Co3O4NPs induced cytotoxicity and genotoxicity in HepG2 cells through ROS and oxidative stress.

Keywords: cobalt oxide nanoparticles, HepG2 cells, cytotoxicity, oxidative stress, DNA damage

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]