Historical
or traditional use (may or may not be supported by
scientific studies)
In
Traditional Chinese Medicine, corydalis is said to
invigorate the blood, move qi (energy that travels
through the body), and alleviate pain, including
menstrual, abdominal, and hernial.
Active
constituents
Scientists
have isolated a number of alkaloids from the tuber of
corydalis, including corydaline, tetrahydropalmatine
(THP), dl-Tetrahydropalmatine (dl-THP), protopine,
tetrahydrocoptisine, tetrahydrocolumbamine, and
corybulbine.Of the full range of 20 alkaloids found in
the plant, THP is considered to be the most potent. In
laboratory research, it has been shown to exhibit a wide
number of pharmacological actions on the central nervous
system, including analgesic and sedative effects. dl-THP
has been found to exhibit a tranquilizing action in
mice. Scientists have suggested that dl-THP blocks
certain receptor sites (e.g., dopamine) in the brain to
cause sedation.
In addition
to its central nervous system effects, studies in the
laboratory have shown the alkaloids from corydalis also
have cardiovascular actions. For example, dl-THP has
been shown to both decrease the stickiness of platelets
and protect against stroke, as well as lower blood
pressure and heart rate in animal studies. Additionally,
it seems to exert an anti-arrhythmic action on the
heart. This was found in a small double-blind clinical
trial with patients suffering from a specific type of
heart arrhythmia (e.g., supra-ventricular premature beat
or SVPB). People taking 300–600 mg of dl-THP per day in
tablet form, had a significantly greater improvement
than those taking placebo pills.
Other human
clinical trials on dl-THP have shown the ability to fall
asleep was improved in people suffering from insomnia
after taking 100–200 mg of dl-THP at bedtime. No drug
hangover symptoms such as morning grogginess, dizziness
or vertigo were reported by people taking the alkaloid
extract.
Reports from
Chinese researchers also note that 75 mg of THP daily
was effective in reducing nerve pain in 78% of the
patients tested. Painful menstruation (dysmenorrhea),
abdominal pain after childbirth, and headache have also
been reported to be successfully treated with THP.
Extracts of
the herb may also be useful in the treatment of stomach
ulcers. In a large sample of patients with stomach and
intestinal ulcers or chronic inflammation of the stomach
lining, a 90–120 mg extract of the herb per day (equal
to 5–10 grams of the crude herb) was found to improve
healing and symptoms in 76% of the patients.
How much is
usually taken?
For an
analgesic or sedative effect, the crude, dried rhizome
is usually recommended at 5–10 grams per day.
Alternatively, one can take 10–20 ml per day of a 1:2
extract.
Are there
any side effects or interactions?
Corydalis
should not be taken by pregnant or nursing women. There
have been several reports in Western journals of THP
toxicity, including acute hepatitis In addition, people
taking corydalis can experience vertigo, fatigue, and
nausea.
At the time
of writing, there were no well-known drug interactions
with corydalis.
