Aluminium oxide nanoparticles induce mitochondrial-mediated oxidative stress and alter the expression of antioxidant enzymes in human mesenchymal stem cells

Abstract

An urgent need for toxicological studies on aluminium oxide nanoparticles (Al₂ NPs) has arisen from their rapidly emerging range of applications in the food and agricultural sectors. Despite the widespread use of nanoscale aluminium and its composites in the food industry, there is a serious lack of information concerning the biological activities of Al₂ NPs (ANPs) and their impact on human health. In this preliminary study, the effects of ANPs on metabolic stress in human mesenchymal stem cells (hMSCs) were analysed. The results showed dose-dependent effects, including cellular toxicity. The mitochondrial membrane potential in the hMSCs decreased with increasing ANP concentrations after 24 h of exposure. The expression levels of oxidative stress-responsive enzymes were monitored by RT-PCR. The expression levels of CYP1A and POR were up-regulated in response to ANPs, and a significant down-regulation in the expression of the antioxidant enzyme SOD was observed. Further, dose-dependent changes in the mRNA levels of GSTM3, GPX and GSR were noted. These findings suggest that the toxicity of ANPs in hMSCs may be mediated through an increase in oxidative stress. The results of this study clearly demonstrate the nanotoxicological effects of ANPs on hMSCs, which will be useful for nanotoxicological indexing.

Keywords:

• Al₂O₃ nanoparticles
• toxicity
• oxidative stress
• antioxidant genes
• mesenchymal stem cells

Acknowledgements

We gratefully acknowledge the financial support of the National Program for Science and Technology, (Grant Number: 10-BIO-981-02) King Saud University, Saudi Arabia. We also acknowledge the excellent technical support of Mr. Jegan Athinarayanan, Department of Food Science and Nutrition, King Saud University.