Effect of Leucine-enkephalin on Lipid Deposition and GSK-3β/mTOR Signaling in the Liver of Zebrafish.

In the current study, we evaluated the effect of leucine-enkephalin (L-ENK) on lipid deposition and GSK-3β/mTOR signaling in zebrafish. Zebrafish were exposed with 2.5, 12.5, and 25 µg/g body weight (bw) L-ENK for four weeks. Our results demonstrated that 2.5, 12.5, and 25 µg/g L-ENK enhanced the hepatic gene expression and activities of fatty acid synthesis enzymes. The level of triglyceride (TG) and the number of lipid droplet was increased by 2.5, 12.5, and 25 µg/g L-ENK treatments. Moreover, 2.5, 12.5, and 25 µg/g L-ENK elevated mTOR and PPARγ gene expression, but inhibited GSK-3β and TSC2 expression in the zebrafish liver. Our results showed that L-ENK induces fatty acid synthesis and lipid deposition, and the signaling GSK-3β/mTOR may be involved in this regulatory process. [ABSTRACT FROM AUTHOR]