Maresins (macrophage mediators in resolving inflammation) are members of a class of potent anti-inflammatory and pro-resolving mediators that are synthesized by macrophages in the presence of docosahexaenoic acid (DHA). Maresin 1 (MaR1) is produced via oxidation of endogenous DHA by 12-lipoxygenase. MaR1 has been shown to reduce neutrophil infiltration in murine peritonitis, enhance efferocytosis, inhibit TRPV1 currents in neurons, reduce neuropathic pain in mice, and attenuate disease severity in mouse models of colitis. Although circulating levels of MaR1 may be quite low, MaR1 can be detected in urine.