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January 02, 2014

Study: Chinese Plant Ingredient Eases Chronic Pain

by Jessica Berman

Researchers have discovered a natural ingredient in an ancient Chinese plant that relieves chronic pain, including backache.  The compound comes from the roots of the flowering Corydalis herb, which the Chinese have used for centuries to treat pain. 

The Corydalis plant is grown primarily in central eastern China. For thousands of years, people in the Asian country have harvested the plant’s roots or tubers, ground them up and boiled them in vinegar.  The concoction, often processed into a tea, was given to treat pain.  Although it is effective in easing all types of pain, including temporary and inflammatory joint pain, it may have its greatest benefit in treating long-term nagging pain, for which experts say there is no good medicine.
 
A researcher with the University of California Davis, Olivier Civelli, says the active compound in Corydalis identified by researchers is dehydrocorybulbine or DHCB. In animal experiments, DHCB appears to work well in easing low-level chronic pain. The plant is a member of the poppy family.
 
Civelli explains so-called opiod drugs like morphine are often given to treat chronic pain when they should only be prescribed for a short period of time because of their addictive properties. 
 
But DHCB, says Civelli, appears to be both effective and non-addictive in the treatment of persistent pain.
 
“So what we find is our compound does not do that.  It does not lose its effect over time.  Because we have injected to animals for seven days and the analgesic effect [pain relieving] we are seeing stays stable,” says Civelli.
 
Addictive drugs act through a morphine pathway in the brain. But Civelli says it appears DHCB works through another brain transport chemical called a dopamine D2 receptor, which studies suggest plays a role in pain sensation.
 
Civelli and colleagues discovered DHCB as part of the “herbalome” project to identify and catalog the active ingredients in traditional Chinese medicine. 
 
Noting new drug development can cost a $1 billion or more, Civelli says the project seeks to discover cost effective, natural compounds.
 
“Trying to understand ... why [Chinese] people are taking it for 3,000 years or something like that?  And it was efficient.  How many compounds are out there that do something for pain relief? And that is what we are interested in doing now,” says Civelli.
 
Corydalis preparations can be purchased on the Internet but without further testing to make sure they are safe, Civelli does not recommend people take them.
 
An article on discovery of the pain relieving ingredient in the ancient Chinese plant Corydalis is published in the journal Current Biology.