If you’ve ever heard any discussions around the topic of opioids, you probably know that there is a lot of controversy and a similar deal of complexity. However, researchers in the medical field remain extremely interested in opioids and their mechanism of action. In the past, many believed that opioid receptors only existed in the central nervous system. But as these receptors have now been found in other areas of the body, the intrigue has only deepened. How do these receptors work? What does this implication have for the future of disease treatment?

According to Medical XPress, a team of researchers from the Tokyo University of Science and the University of Tsukuba recently sought to understand how opioids affected the immune system. Through testing synthesized opioids such as KNT-127 and YNT-2715, the research team found that these drugs could be beneficial for patients with inflammatory bowel disease (IBD). Interested in learning more? Take a look at the full research findings published in Frontiers in Immunology.

Opioids

The Mayo Clinic explains that:

Opioids are a broad group of pain-relieving drugs that work by interacting with opioid receptors in your cells. Opioids can be made from the poppy plant — for example, morphine (Kadian, Ms Contin, others) — or synthesized in a laboratory — for example, fentanyl (Actiq, Duragesic, others).

Within this particular study, researchers sought to understand how opioids impacted the immune system. In particular, they explored an artificially synthesized opioid called KNT-127, which activates the delta-opioid receptor. Normally, these receptors are a target for reducing pain.

To begin, researchers treated mice models of IBD with the synthesized opioid. They found that, following treatment, the mice models had less severe colon inflammation and atrophy. Additionally, the mice models did not lose as much weight. This is important to note as the abdominal pain and appetite loss associated with IBD can translate into unintentional weight loss. Researchers tested this finding and found confirmatory evidence that KNT-127 reduced inflammation within the colon.

Excluding CNS Involvement

But how could researchers be sure that this was not just caused by opioid receptors within the central nervous system? To test this, researchers also treated mice models with YNT-2715. Unlike the first synthesized opioid, YNT-2715 is unable to cross the blood-brain barrier. However, researchers found that this treatment also reduced colon inflammation. Thus, the opioids were working without central nervous system involvement. Additional findings include how treatment reduced pro-inflammatory cytokines like interleukin-6 (IL-6) and pro-inflammatory macrophages. However, it also increased regulatory T cell numbers to help fight inflammation.

Altogether, the researchers determined that opioids like KNT-127, though they often affect the brain, can also have a positive response within the immune system. In this case, the treatments reduced colon inflammation, which could be extremely beneficial for patients with IBD and other related conditions.

However, the researchers do also explain that more research is needed in the future to determine the full potential of this therapeutic option for this patient population.

Inflammatory Bowel Disease (IBD)

Inflammatory bowel disease (IBD) exists as an umbrella term, under which a number of conditions – such as Crohn’s disease and ulcerative colitis (UC) – exist. While doctors are not sure exactly what causes IBD, immune dysfunction is thought to play a role. Patients with IBD experience digestive tract inflammation which can be serious or life-threatening without treatment. Potential risk factors include age (younger than 30), being Caucasian or Ashkenazi Jewish, living in a northern climate, being stressed, or using cigarettes. Symptoms vary between patients, but may include:

• Unintended weight loss
• Appetite loss
• Abdominal pain and cramping
• Fever
• Diarrhea
• Fatigue
• Bloody stool
• Blood clots (complication)
• Colon cancer (complication)
• Joint, skin, and eye inflammation (complication)