Japanese Hop

Chinese
葎草
Pinyin
Lü Cao
Latin
Herba Humuli Scandentis

TCM Properties

Taste
bitter, sweet
Temperature
cold
Channels
Lung, Large Intestine, Kidney

Traditional Use

Primary Actions

  • Clears Heat and resolves toxicity
  • Promotes urination and reduces oedema
  • Clears Lung Heat and suppresses cough
  • Stops dysentery and treats intestinal heat

Secondary Actions

  • Antipruritic — clears Damp-Heat from the skin (eczema, urticaria)
  • Used in folk medicine for pulmonary tuberculosis and chronic colitis

Classical References

  • Ben Cao Gang Mu Shi Yi (Zhao Xuemin, Qing dynasty): lists Lü Cao (葎草) for treating hematuria, strangury, snake and scorpion bites, and sores — consistent with its heat-clearing, urinary-promoting profile
  • Widely documented in Chinese folk medicine of northern and northeastern China for tuberculosis and dysentery; related to brewing hop (Humulus lupulus) but distinct species with different phytochemical and pharmacological profile

Modern Research

Active Compounds

  • Luteolin-7-O-β-D-glucoside (LGL; principal anti-inflammatory flavonoid)
  • Apigenin-7-O-β-D-glucoside (AGL; antipruritic flavonoid)
  • Friedelanone (triterpenoid)
  • Epifriedelanol (triterpenoid)
  • cis-Asarone
  • Stigmasta-4-ene-3,6-dione
  • γ-Sitosterol
  • n-Hexadecanoic acid and linoleic acid

Studied Effects

  • Immunosuppressive: extract significantly inhibited splenocyte proliferation induced by ConA, LPS, and MLR; suppressed CD4+ T cell activation and IFN-γ production via Erk1/2 and P38 MAPK pathway inhibition — supports use in autoimmune-inflammatory Bi syndrome (PMID 25004883)
  • Antipruritic: 40% ethanol fraction inhibited rat peritoneal mast cell degranulation and antigen-stimulated histamine release, and reduced serum IL-4 in murine allergy models; luteolin-7-O-glucoside and apigenin-7-O-glucoside identified as active antipruritic flavonoids (PMID 20619323)
  • Pharmacological review (TCMSP database analysis) confirms anti-inflammatory, antioxidant, hepatoprotective, lipid-lowering, antimicrobial, anti-tumour, and neuroprotective activities across gastrointestinal, respiratory, urinary, and cardiovascular systems

PubMed References

Safety & Interactions

Contraindications

  • Cold-Damp diarrhea or dysentery without Heat signs
  • Spleen-Stomach Deficiency Cold

Cautions

  • Standard dose 10–15g decoction; 30–60g fresh herb
  • Immunosuppressive activity documented in vitro and in vivo; caution in patients on immunosuppressive therapy (potential additive effect) or with known immunodeficiency
  • Not to be confused with Humulus lupulus (brewing hops) — different species with distinct phytochemistry

Drug Interactions

  • Immunosuppressants: preclinical immunosuppressive activity via T-cell inhibition; potential additive effect with pharmaceutical immunosuppressants

Conditions