Metabolism of essential fatty acids (EFAs). Red arrows indicate inhibition of activity of Δ6 and Δ5 desaturases while green arrows indicate enhancement of their activity. It is predicted that under normal oxidative conditions adequate formation of PGE1, PGI2, PGI3, lipoxins, resolvins, protectins, maresins and nitrolipids will occur that would prevent low-grade systemic inflammation and insulin resistance. Isoprostanes and neuroprostanes are also formed from PUFAs under certain specific circumstances that have anti-inflammatory and neuroprotective properties. On the other hand, under conditions of excess oxidative stress not only the formation of PGE1, PGI2, PGI3, lipoxins, resolvins, protectins, maresins, nitrolipids and endothelial nitric oxide is decreased or abrogated but would also lead to the formation of excess of pro-inflammatory eicosanoids such as PGE2, PGE3, PGF2α, PGF3α, leukotrienes and thromboxanes. PUFAs, various eicosanoids, lipoxins, resolvins, protectins, maresins, nitrolipids and endothelial nitric oxide may bring about their various actions by acting or modulating nuclear receptors, LXR, FXR, RAR-RXR, Syntaxin, PPARs, eNO, Ras, GTPases, NF-κB, UCPs, G-protein coupled receptors (GPRs),phospholipases, ROS, anti-oxidants, cytokines, neurotransmitters, growth factors, cytokeratins, various genes, oncogenes and anti-oncogenes.