DHA: Potential safe and cheap therapy for chronic pain

by Bruce Sylvester – Newly published research suggests that a derivative of DHA (docosahexaenoic acid), found in over-the-counter fish oil supplements, might be used to effectively treat and prevent neuropathic pain caused by injuries to the sensory system.

The findings were published online on July 17, 2013 in the Annals of Neurology.

The investigators studied the compound neuroprotectin D1=protectin D1 (NPD1=PD1). The compound appears in human white blood cells, and has previously shown a capacity to resolve abdominal and brain inflammation.

“These compounds are derived from omega-3 fatty acids found in fish oil, but are 1,000 times more potent than their precursors in reducing inflammation,” said lead investigator Ru-Rong Ji, PhD, professor of anesthesiology and neurobiology at Duke University Medical Center in Durham, North Carolina.

Using mouse models, the investigators simulated pain related to nerve injuries, studying symptoms associated with post-surgical nerve trauma.

They treated the animals with chemically-synthesized NPD1=PD1, by local application or injection, studying the efficacy of the lipid compound for relieving symptoms.

They found that that NPD1=PD1 alleviated pain and reduced nerve swelling after injury.

The investigators reported that NPD1=PD1 inhibited the production of cytokines and chemokines,  molecules that attract inflammatory macrophages to nerve cells. They noted that by stopping cytokine and chemokine production, the compound  protects nerve cells from more injury. They also noted that NPD1=PD1 reduced neuron firing, causing so the mice to feel less pain.

As background, the authors said that current treatment options for neuropathic pain include gabapentin and various opioids, which can cause addiction and destruction of sensory nerves. However,  NPD1=PD1 alleviates neuropathic pain at low doses and the animals in the study showed no signs of physical dependence upon or increasing tolerance of NPD1=PD1.

“We hope to test this compound in clinical trials,” Ji said. “DHA is very inexpensive, and can be converted to NPD1 by an aspirin-triggered pathway,” he added.