γ-Linolenic acid prevents conjugated linoleic Acid–Induced fatty liver in mice

Objective The present study was done to clarify the mechanism by which conjugated linoleic acid (CLA) induces fatty liver in mice and to attenuate this symptom by adding other dietary fatty acids. Methods Mice were given CLA short (12 h) or long (4 wk) term or given CLA with linoleic acid (LA) or γ-linolenic acid (GLA) in the long term (4 wk). Total lipids, triacylglycerol, and prostaglandin E2 (PGE2) levels in the liver were determined. Results A single administration of CLA significantly increased PGE2 levels in the liver 12 h after administration. However, long-term administration of CLA significantly decreased the liver PGE2 level and induced fatty liver. GLA increased PGE2 levels, and coadministration with GLA, but not with LA, prevented the CLA-induced fatty liver. Conclusions These data suggest that CLA initially stimulates PGE2 production followed by depletion of PGE2 sources in the liver. The fatty liver associated with PGE2 reduction by CLA ingestion can be attenuated by GLA in mice.