Oleic acid reduces lipopolysaccharide-induced expression of iNOS and COX-2 in BV2 murine microglial cells: Possible involvement of reactive oxygen species, p38 MAPK, and IKK/NF-κB signaling pathways

Microglia are the major cells involved in neuroinflammation resulting in brain tissue damage during infection and neurodegenerative diseases. In this study, we examined the effects of the monounsaturated fatty acid oleic acid (OA) on LPS-induced proinflammatory mediators production and the mechanisms involved in BV2 microglia. OA inhibited LPS-induced expression of iNOS and COX-2 as well as production of NO and prostaglandin E2. We showed that OA blocked LPS-induced NF-κB activation and phosphorylation of inhibitor κB kinase (IKK). We also showed that OA inhibited LPS-induced phosphorylation of Akt and p38 MAPK, but not that of ERK. Finally, we showed that OA reduced reactive oxygen species (ROS) accumulation and an anti-oxidant N-acetylcysteine inhibited NF-κB transactivation and phosphorylation of IKK and Akt in LPS-stimulated BV2 cells. Taken together, our results suggest that OA shows an anti-inflammatory effect by inhibiting ROS, p38 MAPK, and Akt/IKK/NF-κB signaling pathways in LPS-stimulated BV2 microglia.