From:  A novel therapeutic strategy of obesity from the perspective of SPMs

 Summary of SPMs: classification, precursors, and functions.

ClassSubtypes/StructuresPrecursorsKey functions
ResolvinsE-series (RvE1, RvE2): 18-carbon, 3 double bonds;
D-series (RvD1–D6): 22-carbon, 4 double bonds
E-series: EPA;
D-series: DHA
Inhibit neutrophil migration and pro-inflammatory cytokine release; Promote macrophage phagocytosis and resolution of inflammation; Enhance epithelial barrier function; Reduce atherosclerosis by suppressing endothelial adhesion molecules
LipoxinsLXA4, LXB4: 20-carbon, 4 double bonds;
15-epi-LXA4: Isomer with distinct receptor affinity
Arachidonic acid (AA)Block neutrophil recruitment and adhesion molecule expression; Induce apoptosis of pro-inflammatory macrophages; Protect against oxidative stress in tissues; Reduce airway hyperresponsiveness in asthma
ProtectinsPD1 (Neuroprotectin D1): 22-carbon, 5 double bonds;
PDX: Modified structure with enhanced stability
DHAProtect neurons from excitotoxicity and oxidative damage; Modulate microglial polarization toward anti-inflammatory M2 phenotype; Improve cognitive function in Alzheimer’s models; Reduce hepatic steatosis by enhancing fatty acid oxidation
MaresinsMaR1, MaR2: 22-carbon, 4 double bonds
MCTRs (maresin-coupled tissue repair molecules): Peptide-lipid conjugates
DHAPromote macrophage clearance of apoptotic cells; Inhibit Th1/Th17 cell differentiation while enhancing Treg cell function; Accelerate skin and corneal wound healing

SPMs: specialized pro-resolving mediators; EPA: eicosapentaenoic acid; DHA: docosahexaenoic acid.