Anti-inflammatory effects of polyunsaturated fatty acids in THP-1 cells

The effects of linoleic acid (LA), alpha-linolenic acid (ALA), and docosahexaenoic acid (DHA) were compared to that of palmitic acid (PA), on inflammatory responses in human monocytic THP-1 cells. When cells were pre-incubated with fatty acids for 2-h and then stimulated with lipopolysaccharide for 24-h in the presence of fatty acids, secretion of interleukin (IL)-6, IL-1 beta, and tumor necrosis factor-alpha (TNF alpha) was significantly decreased after treatment with LA, ALA, and DHA versus PA (P < 0.01 for all); ALA and DHA elicited more favorable effects. These effects were comparable to those for 15-deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2) and were dose-dependent. In addition, LA, ALA, and DHA decreased IL-6, IL-1beta, and TNF alpha gene expression (P < 0.05 for all) and nuclear factor (NF)-jB DNA-binding activity, whereas peroxisome proliferator-activated receptor-gamma (PPAR-gamma) DNA-binding activity was increased. The results indicate that the anti-inflammatory effects of polyunsaturated fatty acids may be, in part, due to the inhibition of NF-jB activation via activation of PPAR gamma. (c) 2005 Elsevier Inc. All rights reserved.