The Interactions between Metallic Nanoparticles and Cytochrome P450, Alanine Aminotransferase, and Aspartate Aminotransferase Enzyme Hayat A. Al-Btoush Journal of Pure and Applied Microbiology 2023; 17(4), pp. 2024-2040. Abstract The use of metallic nanoparticles (NPs) in various industrial and biomedical fields is increasing exponentially. As a result, research examining the potentially toxic impact of these NPs on human health is also increasing. Cytochrome P450 (P450s) enzymes are important for the endogenous and exogenous molecules metabolism. Inhibition or induction of these enzymes affects xenobiotic detoxification and causes clinically significant drug toxicity or therapeutic failures. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are the most frequently used biomarker for liver injury and their induction is an important indicator of hepatotoxicity. This review aims to understand the existing literature relevant to the effect of metallic NPs on P450s, ALT and AST (aminotransferases) enzymes. It was found that the predominant effect of metallic NPs is the inhibition of the CYP 450 gene and protein expression and induction of aminotransferases, which highlights their potential interaction and induction of drug-associated toxicity as well as their hepatotoxicity. However, further studies are recommended to investigate the effect of NPs size, morphology, surface area, charge, and NPs coating on the expression of these enzymes. Keywords: Cytochrome P450, Alanine Aminotransferases, Aspartate Aminotransferases, Metallic Nanoparticles, Induction, Inhibition