Corydalis ambigua is a tuberous

Tuber

Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months and provide energy and nutrients for regrowth during the next growing season and they are a means of asexual reproduction...

 early flowering east Asian flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

 species. Its exact native range is obscure due to taxonomic confusion. It is one of the sources of the drug tetrahydropalmatine

Tetrahydropalmatine

Tetrahydropalmatine is an alkaloid found in several different plant species, mainly in the Corydalis family, but also in other plants such as Stephania rotunda. These plants have traditional uses in Chinese herbal medicine...

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Medicinal uses

A related species, C. yanhusuo is one of the 50 fundamental herbs used in traditional Chinese medicine

Traditional Chinese medicine

Traditional Chinese Medicine refers to a broad range of medicine practices sharing common theoretical concepts which have been developed in China and are based on a tradition of more than 2,000 years, including various forms of herbal medicine, acupuncture, massage , exercise , and dietary therapy...

. (C. remota is also substituted.) In Chinese it is called yán hú suǒ .

The root of the plant is traditionally used as an analgesic and sedative, used for headache, period pain, spasm pain, gut, smooth muscle and gall bladder pain. It is a dopamine receptor antagonist. Analgesic effects last about 2 hours and it does not create tolerance. The alkaloid tetrahydropalmatine

Tetrahydropalmatine

Tetrahydropalmatine is an alkaloid found in several different plant species, mainly in the Corydalis family, but also in other plants such as Stephania rotunda. These plants have traditional uses in Chinese herbal medicine...

 also has a number of cardiovascular actions.
Derivatives of tetrahydroprotoberberines were found to be useful to increase pain tolerance and for treating drug addiction. Further they may represent a category of neurotransmitter stabilizer which has potential use in broad range of psychotic and neurological disorders.

Chemistry

Corydalis ambigua contains a variety of alkaloids including corynoline, acetylcorynoline d-corydalin, dl-tetrahydropalmatine

Tetrahydropalmatine

Tetrahydropalmatine is an alkaloid found in several different plant species, mainly in the Corydalis family, but also in other plants such as Stephania rotunda. These plants have traditional uses in Chinese herbal medicine...

, protopine

Protopine

Protopine is a benzylisoquinoline alkaloid occurring in opium poppy, corydalis tubers and other plants of the family papaveraceae. It has been found to inhibit histamine H1 receptors and platelet aggregation, and acts as an opioid analgesic....

, tetrahydrocoptisine, dl-tetrahydrocoptisine, d-corybulbine and allo-crytopine.