Parenteral nutrition-associated liver disease (PNALD) is a liver dysfunction caused by various risk factors presented in patients receiving total parenteral nutrition (TPN).Omega-6 rich Intralipid(R) and omega-3 rich Omegaven(R) are two intravenous lipid emulsions used in TPN.TPN could affect the hepatic expression of genes in anti-oxidative stress,but it's unknown whether TPN affects genes in drug metabolism.In this study,either Intralipid(R)-or Omegaven(R)-based TPN was administered to mice and the expression of a cohort of genes involved in anti-oxidative stress or drug metabolism was analyzed,glutathione (GSH) levels were measured,and protein levels for two key drug metabolism genes were determined.Overall,the expression of most genes was downregulated by Intralipid(R)-based TPN (Gstpl,Gstml,3,6,Nqo1,Ho-1,Mt-1,Gclc,Gclm,Cyp2d9,2f2,2b10,and 3a11).Omegaven(R) showed similar results as Intralipid(R) except for preserving the expression of Gstml and Cyp3a11,and increasing Ho-1.Total GSH levels were decreased by lntralipid(R),but increased by Omegaven(R).CYP3A11 protein levels were increased by Omegaven(R).In conclusion,TPN reduced the expression of many genes involved in anti-oxidative stress and drug metabolism in mice.However,Omegaven(R) preserved expression of Cyp3a11,suggesting another beneficial effect of Omegaven(R) in protecting liver functions.