Resolvins and their routes of formation. (a) Omega-3 polyunsaturated fatty acids include DHA and EPA, and are derived from dietary essentially fat (especially enriched in fish). RvD1 and AT-RvD1 are derived from DHA, whereas RvE1 is derived from EPA. Distinct synthetic enzymes, including COX-2, cytochrome P450, and 5- and 15-lipoxygenase are involved in these processes. See Ref [49] for detailed review on the biosynthesis of resolvins. (b) Chemical structures of the resolvins that are discussed in this review.