Anti-pain peptide a possible alternative to addictive opioids

Opioids such as oxycodone or morphine work very well against pain. Unfortunately, they are also very addictive. So, scientists have long sought a better, safer way to treat chronic pain. Researchers at the Indiana University School of Medicine think they've found something in a peptide that short circuits a pathway for chronic pain, according to a release from the university. Not only that, but also no side effects such as reduced motor coordination, memory loss, depression or addiction.

The peptide is called CBD3 and, unlike other substances that block pain signals, it does not inhibit calcium, which is important in regulating heart rhythm and vital functions in other organs. "After opioids--the gold standard for pain control--the next target is calcium channels," researcher Rajesh Khanna said in the release. "Along the pain pathway in the spinal cord, there are pain-sensing neurons called nociceptors that have an abundance of calcium channels."

Calcium is key in sensing pain, the researchers say, so while they don't want to block the beneficial flow of calcium, they do want to alter it a bit to block what the researchers called the "excitability signals" that the brain interprets as pain. And it's worked in mice, researchers say, much to the rodent's relief. The peptide interfered with signals that navigate calcium channels to produce pain.

"Since our approach does not directly inhibit calcium entry through voltage-gated channels, we expect that this molecule will be more specific and have fewer side effects than currently available analgesics," Khanna said in the release. "We anticipate that this peptide will serve as a novel pharmacological therapeutic for the relief of chronic pain."

- read the release from Indiana University School of Medicine
- and the abstract in Nature Medicine