Chiang Mai Journal of Science

The rapid growth of the nanotechnology industry has led to the wide-scale production and application of engineered nanoparticles (NPs). The purpose of this study is to evaluate the toxicity of oral exposure to zinc oxide nano-particles (ZnO-NPs) on liver tissue of Wistar albino rats, and the hepatoprotective effect of quercetin (Qur) and/or L-Arginine (L-Arg) against such ZnO-NPs –induced toxicity. ZnO-NPs were administered orally in two doses (either 600mg or 1g/Kg body weight/day for 5 consecutive days) to rats.  In order to detect the protective effects of the studied antioxidants against ZnO-NPs induced hepatotoxicity, biomarkers of metabolic disorder, tissue damage and inflammation, as well as oxidative deoxyribonucleic acid (DNA) damage were investigated.   Co-administration of Qur (200mg/Kg body weight) and/or  L-Arg (200mg/Kg body weight) daily for three weeks to ZnO–NPs  intoxicated rats, with either of the two doses,  significantly  down-modulated  the dramatic alteration in the investigated biochemical parameters. Where, the significant increase in serum alanine amino transferase (ALT) (marker of liver tissue damage), glucose (marker of metabolic disorder) levels, and the level of the pro-inflammatory biomarkers including tumor necrosis factor- α(TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP),  as well as  immunoglobin g (IgG) were significantly decreased in treated group as compared to intoxicated rats. Furthermore, the studied antioxidants either alone or in combination effectively ameliorated the hepatic oxidative damage in DNA induced by of ZnO-NPs as confirmed by comet assay.  These results support the use of Qur and L-Arg  as protective agents against metal oxide nanoparticles hepatotoxicity, with their combination achieving a powerful hepatoprotective action.