What is Corydalis and How Can it Support Pain Relief?
Corydalis yanhusuo is a flowering herbal plant that has been used as a folk remedy for pain throughout the centuries. While its pain-relieving properties have been well substantiated, its mechanisms of action have been less understood.
A new study from University of California, Irvine researchers helps to shed light on how corydalis yanhusuo, or YHS, affects the body’s response to chronic pain.
Chronic neuropathic pain is typically connected to some type of tissue injury that resulted in damaged or impaired nerve fibers. The damaged nerves misfire signals to pain centers in the body. So even in the absence of an injury, pain signals are still registering in the body, causing chronic pain.
Taking over-the-counter and prescription analgesics to alleviate chronic pain carries unwanted side effects and risks, such as constipation, dizziness, nausea and vomiting, drowsiness, liver damage, and addiction.
YHS is a natural and much safer alternative to pharmaceutical pain pills for managing low to medium chronic pain. And the latest study published online in PLOS ONE shows that YHS doesn’t lose effectiveness over time like other pain medications do.
Scientists discovered that YHS helps to ease pain by exerting an effect on dopamine, the neurotransmitter that regulates thinking, memory, movement, and reward.
The Dopamine Dilemma
Despite that dopamine plays a role in pain relief, science also shows that dopamine may play a key role in chronic pain by keeping those messages passing from the brain to pain centers in the body.
We can, however, allay the effects of dopamine on pain. A 2015 animal-model study published in the Journal of Neuroscience showed that chronic pain could be greatly reduced by removing cells made up of dopamine.
For the most recent study, researchers gave mice YHS 4 times during a week, and then measured their pain response. The pain-relieving abilities of YHS never faltered, while the potency of morphine wore off as the mice became immune to the drug’s effects. Researchers believe the pain-relieving properties of YHS are partly due to tetrahydropalmatine (THP), one of 20 alkaloids in YHS. THP may be able to block certain receptor sites, such as dopamine receptor sites, in the brain. One study showed that THP was able to reduce nerve pain in 75% of test subjects. THP has also been shown to effectively treat pain associated with menstruation, abdominal pain after childbirth, and headaches.
Olivier Civelli, professor and chair of pharmacology at the University of California, Irvine, notes: “YHS is not a highly potent medicine when compared to morphine. But I would propose that it can be used for low to moderate chronic pain.”
Supplementing with YHS
According to the University of Michigan Health System, alternative medical practitioners recommend using 5 to 10 grams of the crude, dried rhizome of YHS a day, or taking 10-20 ml of a 1:2 extract of YHS. Traditional Chinese Medicine practitioners usually combine YHS with other pain-relieving herbs, such as frankincense, myrrh, cinnamon bark fennel, or liguisticum, depending on the type of pain being treated.
A word of caution: experts advise that you should never take YHS if you are pregnant or nursing. Meanwhile, it’s always recommended to consult a licensed medical professional before taking an herb for pain management.
Root extracts from the flowering herbal plant Corydalis yanhusuo, or YHS, has widely used for centuries as a pain treatment. Yet few studies have investigated how it works on different forms of pain, and little is known about its molecular mechanisms.
Most notably it can reduce chronic neuropathic pain which is poorly treated with common medicines. They also show that YHS seems to not lose its potency over time, as happens with many analgesics. Study results appear in one open-access online journal, PLOS ONE.
The researchers analyzed YHS pain relief properties in mouse tests that monitor acute, persistent inflammatory and chronic neuropathic pain, respectively, while in vitro tests revealed its mechanism of action as a prominent dopamine receptor blocker. Interestingly, in mice that have no dopamine D2 receptor, YHS effect is weakened in neuropathic pain.
Dopamine is an important neurotransmitters that when released from nerve cells to send signals to other nerves. It is known to be involved in reward but studies have also shown that dopamine may play a role in maintaining chronic pain, and that removing dopamine-containing cells can reduce this pain.
Additionally, the researchers found that YHS use did not lead to tolerance. They administered YHS four times over a seven-day period and measured the mice responses in acute pain, noting that YHS kept its potency while morphine lost its.
Since YHS is a dietary supplement commercially available in the United States, Civelli suggests that it might be an adjunct medicine for alternative pain treatment. "YHS is not a highly potent medicine when compared to morphine," he said. "But I would propose that it can be used for low to moderate chronic pain."