Corydalis herb by Ray Sahelian, M.D.
April 3 2014

Corydalis yanhusuo is an herb used in Chinese herbal medicine.

Corydalis and Allergy
An alkaloidal component, dehydrocorydaline, isolated from Corydalis Tuber (tuber of Corydalis turtschaninovii forma yanhusuo), inhibits antibody-mediated allergic reactions but also influences cell-mediated allergic reactions. The inhibitory effect of Corydalis Tuber on allergic reactions may be partially attributed to dehydrocorydaline.

Corydalis and Heart
Corydalis yanhusuo rhizoma extract reduces infarct size and improves heart function during myocardial ischemia/reperfusion by inhibiting apoptosis in rats.
Phytother Res. 2006.
The aim of the present investigation was to evaluate the effect of an extract from Corydalis yanhusuo, a Chinese herbal medicine, on ischemia /  reperfusion injury and to determine the mechanism involved.. These results suggest that the protective effect of Corydalis yanhusuo on myocardial ischemia /  reperfusion injury is closely associated with the inhibition of myocardial apoptosis through modulation of the Bcl-2 family.

Corydalis and pain relief
Effects of Corydalis yanhusuo and Angelicae dahuricae on cold pressor-induced pain in humans: a controlled trial.
J Clin Pharmacol. 2004.
In this controlled clinical trial, the authors evaluated the analgesic effects of 2 herbal medicines, Corydalis yanhusuo and Angelicae dahuricae. They used the cold-pressor test-a simple, reliable, and widely used model in humans-for induction of tonic pain. They demonstrated that after a single, oral administration of the extracts of Corydalils yanhusuo and A. dahuricae, the pain intensity and pain bothersomeness scores significantly decreased . Dose-related analgesic effect was also observed. Results from this study suggest that Corydalis yanhusuo and A. dahuricae may have a potential clinical value for treating mild to moderate pain.

Corydalis and Cataract
Studies of anti-cataract drugs from natural sources. I. Effects of a methanolic extract and the alkaloidal components from Corydalis tuber on in vitro aldose reductase activity.
Biol Pharm Bull. 1994.
The inhibitory of Corydalis tuber (Corydalis turtschaninovii Besser forma yanhusuo Y. H. Chou et C. C. Hsu) was tested on crude rat lens aldose reductase, an enzyme involved in the complications of diabetes. The methanolic extract inhibited aldose reductase, while the aqueous extract (CA-ext) was ineffective. Only dehydrocorydaline, of the seven alkaloidal components isolated from corydalis methanol extract inhibited aldose reductase. It is suggested that the inhibitory effect of corydalis methanol extract on aldose reductase may be partially attributed to dehydrocorydaline.

Corydalis and Inflammation
Anti-inflammatory activities of methanolic extract and alkaloidal components from Corydalis tuber.
Biol Pharm Bull. 1994.
A methanolic extract (CM-ext) from Corydalis tuber (Corydalis turtschaninovii Besser forma yanhusuo Y. H. ) has been screened for activity in experimental models of inflammation. Corydalis methanol extract and its alkaloidal components, dehydrocorydaline, d-glaucine and l-tetrahydrocoptisine inhibited compound 48/80-induced histamine release from peritoneal mast cells of rats. Since these substances from Corydalis tuber were found to be effective in both the acute and chronic phases of inflammation, the crude drug Cprydalis tuber can be considered to exert anti-inflammatory activity.

Side effects, safety
Googling around I came across this ;"The active content of the rhizome varies from field to field. I suggest a reference work, such as "The Illustrated Chinese Materia Medica of Crude and Prepared" by Kun-Ying Yen for such information. Some people have a genetic pre-determination to develop liver conditions that can degenerate into hepatitis when using this product. If at all possible, have a doctor check your liver enzyme panel after using it for no more than a few weeks to see if there is an elevated bilirubin level, in which case you should stop using corydalis."

Korean J Hepatol. 2009. A case of acute cholestatic hepatitis induced by Corydalis speciosa. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea. We report herein a case of hepatotoxicity induced by Corydalis speciosa Max. A 37-year-old male complained of jaundice and mild abdominal discomfort. A thorough history was taken, and laboratory investigation, diagnostic imaging studies, and percutaneous liver biopsy sampling were conducted to determine the cause of liver injury. An accurate cause was not revealed. We administered supportive management for acute cholestatic hepatitis of unknown origin, after which his symptoms disappeared and serum aminotransferase levels decreased gradually to near normal levels. However, at 2 months after discharge, the symptoms and the elevation of aminotransferase levels recurred. At that time he told us that he had repeatedly but unintentionally eaten a herb called "Hwang-geun cho" (Corydalis speciosa Max.). Thus, we diagnosed his case as herbal hepatotoxicity.

Corydalis Yanhusuo emails
Q. Do you know about this Chinese medicinal herb. The herb itself is very hard to source. It's active ingredient is THP, or tetrahydrapalmatine. Om Chi herbs (in Oregon and on the web) has an extract of the herb that is 80% THP. I have used that extract. Also I have obtained from a friend in Europe some wild harvested Corydalis Lutea. So I have tried that species of herb in teas, as well as the extract. I found that a dose of 50mg of extract for my 120lb wife, and 75mg of the extract for myself (225 lbs), (yes I do own a very accurate milligram scale) was very effective in inducing sleep within 30-60 minutes. I would characterize it as a restful sleep. And as long as you don't do something stupid (like take a cap after midnight and expect to wake up for work at 4:30am), there is no grogginess in the morning. The tea with the Corydalis Lutea also worked, but not as easy to deal with. It required relatively a lot of herb. Anyway I was wondering your opinion of this herb / extract, and it's relative safety to use occasionally for sleep. My idea of occasionally is somewhere between 1-12 times in a month maximum, and only when something is keeping me from sleeping.