Resolvins, naturally-occurring lipids derived from omega-3 fatty acids, may represent a new class of painkillers for treating inflammatory pain, suggests a report published online this week in Nature Medicine. The scientists propose that resolvins may prove effective as analgesics by reducing inflammation and acting in the spinal cord to prevent chronic pain.

Inflammatory pain, such as arthritic and post-operative pain, is triggered by tissue injury, leading to the release of compounds that increase inflammation and act within the spinal cord to cause persistent pain.

Ru-Rong Ji and colleagues found that two resolvins, RvE1 and RvD1, which are naturally produced from certain omega-3 fatty acids, reduce inflammatory pain symptoms when administered to mice. The team showed that RvE1 was 10,000 times more potent at alleviating pain than its parent compound; moreover, an artificial compound, Chemerin, which binds to the same receptor as RvE1 and RvD1 also significantly reduced pain symptoms. Aside from their established anti-inflammatory effects, they also found that RvE1 acts in the spinal cord to prevent persistent neuronal activation which normally causes chronic pain. These analgesic effects were seen without any alterations in normal sensitivity to pain.