Individual Herbs Notebook

Hu Zhang

Pharmaceutical: Rhizoma Polygoni cuspidati
Taxonomy: Polygonum cuspidatum

Other names: Japanese Knotweed Root

Category: Herbs that Regulate the Blood



Properties: Bitter and cold

Meridans Entered:
Primary: Liver, Gallbladder and Lung


Traditional Actions/Indications:
  1. Invigorates the Blood, dispels Blood Stasis, unblocks the channels and stops pain
    Amenorrhea due to Blood Stasis
    Wind-Damp Bi
    Traumatic injury
  2. Clears Heat and resolves Dampness
    Damp-Heat jaundice
    Turbid vaginal discharge
    Turbid, painful urinary dysfunction
  3. Discharges toxins and disperses swelling
    Toxic skin conditions, burns and carbuncles
  4. Drains Heat, transforms Phlegm and stops cough
    Lung Heat cough
    Constipation due to clumping of Heat

Suggested Daily Dosage: 9-15g in decoction.


Cautions: It is contraindicated for pregnant women.

Caution should also be taken if growing or wild foraging as careless harvesting can encourage propagation which is illegal in the UK due to the extreme invasive nature and damage to property values and biodiversity that this plant can do.


Notable Constituents:
  1. Resveratrol
    Polyphenol best known for being the component in grape skins that gives red wine its ability to combat age related diseases. It has been found to have antioxidant and potential chemopreventive activities, anti-inflammatory effects and prevent cancer by inhibiting initiation, progression and promotion of tumor genesis. It also promotes both mitochondrial biogenesis and mitophagy to ensure quality control and protects brain and heart mitochondria from oxidative stress leading to senescence.
  2. Polydatin
    Precursor of resveratrol that is easily transformed in vivo.
  3. Emodin
    Anthraquinone that acts as a tyrosine kinase inhibitor (anti-cancer, especially leukemia), an antineoplastic agent and a laxative.

Appears in 7 formulae listed on this site: (click to display)
Research Links & References: (click to display)