Resolvins are potent analgesics for arthritic pain

Arthritis-associated inflammatory pain represents a serious medical problem worldwide. Current treatments for arthritic pain are not very effective and cause unwanted side effects. Resolvins, including the resolvin D and resolvin E series, are a family of novel endogenous lipid mediators derived from omega-3 polyunsaturated fatty acids and display potent anti-inflammatory and pro-resolution actions in animal models of inflammation. Emerging evidence also points to a potent anti-hyperalgesic role of resolvins in animal models of inflammatory pain. The study by Lima-Garcia et al. in this issue of the BJP demonstrated that systemic treatment with 17(R)-hydroxy-docosahexaenoic acid (17(R)HDoHE), the precursor of resolvin D series and its product, aspirin-triggered resolvin D1 (AT-RvD1), at very low doses (1 mg.kg(-1)), reduced inflammatory pain in an adjuvant-induced arthritis model. Particularly 17(R) HDoHE reduced joint stiffness but not paw and joint oedema. Given their potency and safety profile, resolvins may represent a new class of analgesics well suited to treating inflammatory pain associated with arthritis.