Abstract
Silver nanoparticles (AgNPs) are increasingly used in various products and consequentially the potential adverse effects associated with exposure to them are of concern. This study investigated the effects of AgNPs on the hepatic drug-metabolizing enzymes of the cytochrome P450 (CYP) families 1, 2 and 3, using both in vitro and in vivo biological assays. AgNPs were orally administered to Sprague-Dawley rats at various concentrations (0–1000 mg/kg body weight/day) for 2 weeks. No effect was found on the plasma levels of ALT, AST and ALP in all treated rat groups, and no significant change in the activities of CYP1A, CYP2C, CYP2D, CYP2E1 and CYP3A was observed for all tested AgNP doses. The results correlated with the observation that no AgNPs were detected in the liver sections of the tested rats. However, the in vitro system using rat liver microsomes demonstrated a strong inhibition of CYP2C (IC50 = 28 µg/mL) and CYP2D (IC50 = 23 µg/mL) activities, but not of CYP1A, CYP2E1 and CYP3A activities (IC50 > 100 µg/mL) at concentrations up to 100 µg/mL of AgNPs. The inhibitory effect of AgNPs on these CYPs indicates the possibility of the AgNP-drug interaction when co-administered with some medicines and this may cause adverse effects to patients.
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Acknowledgements
We thank Dr. Robert Butcher for his comments and English language review.
Declaration of interest
The authors report no declarations of interest. This work was financial supported by the Research, Development and Engineering Fund of the National Nanotechnology Centre, NSTDA, Thailand and from the Laboratory of Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Japan.