A plant used in traditional Chinese medicine has been found to have potent pain-reliving properties, researchers have found.
The flowering plant Corydalis, a member of the poppy family, has been used for centuries for pain relief in Chinese medicine.
However, researchers have now found it contains a compound called dehydrocorybulbine (DHCB), which has the potential to lead to new drug therapies for people experiencing chronic pain.
DHCB was found in the roots of the plant, the authors from the University of California report in the Cell Press journal Current Biology.
The discovery was made by researchers working on the 'herbalome' project, which looks to catalogue all the chemical components used in traditional Chinese medicine.
Olivier Civelli, one of the authors, said: "Our study reports the discovery of a new natural product that can relieve pain. This analgesic acts in animal assays against the three types of pain that afflict humans, including acute, inflammatory, and neuropathic or chronic pain."
In traditional Chinese medicine, Corydalis is picked, ground and boiled in hot vinegar. It is prescribed to treat pain, such as headaches and back pain.
The scientists found it appeared to work in a similar way 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 said.
Although the drug can be used to treat all types of pain, the researchers say it holds particular promise for people suffering from persistent low-level chronic pain as it does not appear to lose its effectiveness over time, as traditional opiate-based drugs do.
Civelli said: "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."