A compound found in a plant used for centuries in China as a pain reliever may be effective in treating low-level chronic pain, according to researchers at the University of California Irvine.
The compound, known as dehydrocorybulbine (DHCB), is found in the roots of the flowering plant Corydalis, a member of the poppy family. Underground tubers of the Corydalis plant are harvested, ground, and boiled in hot vinegar. Corydalis tinctures are usually blended with other herbs and used to treat headaches, menstrual pain, stomach pain and back pain.
Although the analgesic effect of Corydalis is similar to that of the opium poppy, it is believed to be non-addictive.
“Our study reports the discovery of a new natural product that can relieve pain,” says Olivier Civelli, PhD, Department of Pharmacology at the University of California, Irvine, “This analgesic acts in animal assays against the three types of pain that afflict humans, including acute, inflammatory, and neuropathic or chronic pain.”
Civelli and his research team made the discovery as part of the “herbalome” project, an effort to catalogue all of the chemical components of traditional Chinese medicine. They reported the findings in the journal Current Biology.
Ten herbs known for their analgesic properties were studied for the effects on opioid receptors. Corydalis was found to be the most effective, so the researchers went looking for compounds in Corydalis that appeared likely to act in a manner similar to morphine.
“We landed on DHCB but rapidly found that it acts not through the morphine receptor but through other receptors, in particular one that binds dopamine,” Civelli explains.
In tests on laboratory mice, researchers found that synthetic DHCB was effective at relieving several types of pain.
“Synthetic DHCB was used to show that it is effective at alleviating thermally as well as chemically induced acute pain and inflammatory-induced persistent tonic pain. It is effective at doses that do not induce sedation and at high doses exerts an antinociceptive response similar to that obtained with morphine. Furthermore, DHCB is effective at relieving injury induced neuropathic pain,” they wrote.
While Corydalis extracts or DHCB work against all types of pain, they hold special promise for those who suffer from low-level chronic pain. For one thing, DHCB doesn’t appear to lose its effectiveness the way that traditional opiate drugs do.
“We have good pain medications for acute pain: codeine or morphine, for example. We have pain medication for inflammatory pain, such as aspirin or acetaminophen. We do not have good medications for chronic pain. DHCB may not be able to relieve strong chronic pain, but may be used for low-level chronic pain,” Civelli said.
Although Corydalis tinctures can be found online and in health food stores, Civelli says DHCB isn’t ready for prime time just yet. Further testing for toxicity is needed before doctors should consider prescribing it to patients.