Anti-Inflammatory Effects of Stearidonic Acid Mediated by Suppression of NF-κB and MAP-Kinase Pathways in Macrophages

Stearidonic acid (SDA, 18:4n-3) is an omega-3 polyunsaturated fatty acid present in oils derived from plants of the Boraginaceae family. In this study, we determined the anti-inflammatory effects of SDA isolated from echium oil on lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 macrophages. SDA significantly downregulated the levels of the inducible nitric oxide synthase (iNOS) protein, thereby suppressing the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 cells. In addition, SDA inhibited the nuclear translocation and promoter activity of nuclear factor κB (NFκB) and the phosphorylation of mitogen-activated protein kinases (MAPK) such as extracellular signal regulated kinase 1/2, c-jun N terminal kinase, and p38 in LPS-stimulated RAW 264.7 cells. Our results showed that SDA exerted anti-inflammatory effects by suppressing iNOS-mediated NO production via inactivation of NFκB and MAPK signaling pathways.