Heartleaf Houttuynia

Chinese
鱼腥草
Pinyin
Yu Xing Cao
Latin
Herba Houttuyniae

TCM Properties

Taste
acrid
Temperature
slightly cold
Channels
Lung, Large Intestine, Bladder

Traditional Use

Primary Actions

  • Clears Heat and resolves toxicity (especially Lung heat-toxicity)
  • Drains Lung abscess and expels pus
  • Clears Damp-Heat and promotes urination
  • Reduces swelling and relieves inflammatory pain

Secondary Actions

  • Broad-spectrum antibacterial for respiratory and urinary tract infections
  • Antiviral support; used in SARS prevention protocols in China

Classic Formulas

  • Wei Jing Tang (苇茎汤) — classic formula for Lung abscess; Yu Xing Cao added in modern modifications to strengthen heat-clearing and pus-expelling action
  • Used as principal herb in numerous modern patent formulas for pneumonia, bronchitis, and upper respiratory infections

Classical References

  • Ben Cao Jing Shu (Qing dynasty): 'Yu Xing Cao clears the Lung heat, dissipates toxicity, and discharges pus — the essential herb for heat abscess of the Lung'
  • Named for its distinctive fishy odour (鱼腥 = fishy smell); the volatile compound houttuynin (decanoylacetaldehyde) is responsible and degrades on prolonged cooking — add late in decoction or use fresh

Modern Research

Active Compounds

  • Houttuynin / decanoylacetaldehyde (volatile antibacterial; degrades on heating)
  • Quercetin
  • Rutin
  • Hyperin (quercetin-3-galactoside)
  • Quercitrin
  • Kaempferol
  • Aristolactams A and B (present at low levels; structurally distinct from nephrotoxic aristolochic acids)

Studied Effects

  • Antiviral: H. cordata extract and quercetin inhibit murine coronavirus and dengue virus; quercetin, baicalin, and luteolin identified as SARS-CoV-2 protein inhibitors with experimental validation showing inhibition of LPS-induced IL-6 and IL-1β and pseudovirus cell invasion (PMID 34512097)
  • Antibacterial: sodium houttuyfonate shows synergistic activity against MRSA combined with EDTA-Na2, significantly improving survival in murine infection model; nutraceutical review confirms broad antiviral spectrum (PMID 36059903)
  • Anti-inflammatory: water and ethanolic extracts reduce NO and TNF-α production in LPS-stimulated macrophages by up to 30% via NF-κB inhibition

PubMed References

Safety & Interactions

Contraindications

  • Cold-Damp Lung patterns (cough with clear-white phlegm, no fever)
  • Spleen-Stomach Deficiency Cold

Cautions

  • Standard dose 15–30g fresh herb or 15–25g dried in decoction; add in final 5 minutes to preserve volatile houttuynin
  • Aristolactams A and B are present at low levels; aristolochic acids (the nephrotoxic compounds) are absent or below detection — avoid prolonged unsupervised use as precaution
  • Injectable preparations (sodium houttuyfonate injection) were suspended nationally in China in 2006 following serious allergic reactions; injectable form is NOT equivalent to oral/decoction safety profile
  • Oral and topical use considered safe at standard doses based on centuries of use

Drug Interactions

  • Anticoagulants / antiplatelet drugs: possible additive blood-thinning effect due to quercetin content; monitor for increased bleeding risk
  • Immunosuppressants: potential additive immunomodulatory effect; caution in transplant patients or those on immunosuppressive therapy

Conditions