The role of long chain fatty acids and their epoxide metabolites in nociceptive signaling

• Long chain fatty acids mediate analgesia in acute and neuropathic pain models.
• Omega-3 and omega-6 epoxy fatty acids demonstrate potent analgesia.
• PUFA elicited analgesia may be mediated by epoxidized fatty acid metabolites.
• Soluble epoxide hydrolase inhibition elevates epoxide metabolites and is analgesic.

Lipid derived mediators contribute to inflammation and the sensing of pain. The contributions of omega-6 derived prostanoids in enhancing inflammation and pain sensation are well known. Less well explored are the opposing anti-inflammatory and analgesic effects of the omega-6 derived epoxyeicosatrienoic acids. Far less has been described about the epoxidized metabolites derived from omega-3 long chain fatty acids. The epoxide metabolites are turned over rapidly with enzymatic hydrolysis by the soluble epoxide hydrolase being the major elimination pathway. Despite this, the overall understanding of the role of lipid mediators in the pathology of chronic pain is growing. Here, we review the role of long chain fatty acids and their metabolites in alleviating both acute and chronic pain conditions. We focus specifically on the epoxidized metabolites of omega-6 and omega-3 long chain fatty acids as well as a novel strategy to modulate their activity in vivo.