Nutrition, Companionship Reduce Pain in Mice With Sickle Cell Disease

Researchers from the University of California, Irvine (UCI) and the University of Minnesota have found that an enriched diet and companionship can reduce pain in mice with sickle cell disease by increasing serotonin. They also discovered that duloxetine, an antidepressant that boosts serotonin levels, could be an alternative to opioids in treating chronic pain.

“Finding safe and effective alternatives to opioids is a research priority, especially for patients with sickle cell disease,” says Keith Hoots, MD, director of the division of blood diseases and resources at the National Heart, Lung, and Blood Institute. “It’s encouraging to see a dose-response relationship to nutrients and companions in mice, which guides future research about the role foods and friends may have in helping humans manage chronic pain.”

Scientists have long suspected that feeling pain is connected to a person’s mood or state of mind, but the link has never been proven beyond doubt. This study, published in Scientific Reports, supports that connection.

“Part of pain is perception,” says Kalpna Gupta, PhD, a visiting professor of medicine at UCI and the study’s lead author. “For instance, if I start watching a comedy, suddenly I might forget that I was hurting; mood and a feeling of well-being block pain from being perceived.”

Sickle cell disease is a painful, lifelong condition that affects about 100,000 Americans, according to the Centers for Disease Control and Prevention, the majority of whom are African American. Opioids are the most common method of treating their pain. But because they’re addictive, and overdoses are a leading cause of death in the United States, Gupta’s team has been investigating alternatives.

“By suggesting a safe alternative to opioids for pain control, the findings of this study have the potential to change the practice of pain management and save lives,” says study coauthor Rajendra Badgaiyan, MD, a professor of psychiatry at the University of Minnesota at the time who’s now at the University of Texas Health Science Center in San Antonio.

The researchers found that mouse models of sickle cell disease in a “happy environment” experienced less pain from the disorder. Over a four-week period, pain was reduced for male mice that were placed with female companions and received a diet rich in protein, fatty acids and amino acids.

Their pain decreased as the diet and companionship caused their brains to secrete serotonin. Researchers quantified the mice’s pain according to the frequency with which they lifted their paws in response to stimuli and by their ability to exert force.

To confirm that serotonin caused the reduction in pain, the mice were given duloxetine, an antidepressant that works by raising the amount of serotonin in the brain. The drug decreased pain levels for both male and female mice.

The researchers believe that adapting these conditions for humans would produce the same results. Gupta is recommending that duloxetine be used in clinical trials for sickle cell patients as an alternative to opioids for pain relief.

— Source: University of California, Irvine