Ranunculaceae
Coptis chinensis
Huang lian · Chinese goldthread
- Part used
- rhizome
- Native range
- China
- Morphology
- A small woodland perennial with divided glossy leaves and inconspicuous greenish-white flowers, over a knotted bright yellow rhizome.
What is in it
Evidence
Berberine, its principal alkaloid, has reasonable trial evidence for glycaemic control and lipid lowering — from berberine supplements, generally not from Coptis. Attributing that evidence to the herb is a common and unjustified move.
Safety
Berberine displaces bilirubin from albumin and causes kernicterus in newborns; Coptis and other berberine-containing herbs are contraindicated in neonates and in pregnancy. Berberine is a potent inhibitor of drug-metabolising enzymes and transporters, making interactions likely and unpredictable.
Interactions: Strong CYP3A4 inhibition raises levels of many drugs; Additive with antidiabetic drugs; Contraindicated in pregnancy and in newborns
Regulatory: Restricted in several jurisdictions. Berberine is sold separately as a supplement in many markets.
How the traditions classify it
Three systems, rating the same plant. Where they disagree, none of them is correcting the others — they are separate frameworks that arrived at their categories independently.
Historical use
In the Shennong Bencao Jing and used continuously for feverish and inflammatory conditions and for dysentery.
Recorded as history and attributed where possible. Long use establishes that a plant was widely used, not that it worked, and not that it was safe.
Worth knowing
Berberine appears in this collection three times — in Coptis, in goldenseal and in barberry — in three unrelated families on two continents, which is a striking piece of convergent chemistry.
It is also the clearest example of evidence migrating from a compound to a plant that does not own it. Berberine supplements have decent trials for blood glucose. Those trials say nothing about Coptis chinensis, which contains berberine among several other alkaloids at variable concentration, and is sold on the strength of results it did not produce.
The neonatal contraindication deserves more prominence than it usually gets. Berberine competes with bilirubin for albumin binding, which in a newborn can precipitate kernicterus — a preventable cause of permanent brain injury.
Nomenclature verified against GBIF backbone taxonomy.