Bark of Silktree Albizzia

Chinese
合欢皮
Pinyin
He Huan Pi
Latin
Cortex Albiziae

TCM Properties

Taste
sweet
Temperature
neutral
Channels
Heart, Liver, Lung

Traditional Use

Primary Actions

  • Calms the spirit and relieves emotional constraint - the signature bark herb for depression, anxiety, insomnia, irritability, grief, and constrained Liver-Heart disharmony when the Shen cannot rest.
  • Invigorates Blood and reduces swelling - used for traumatic injury, pain from bruising or fracture, and localized swelling where emotional trauma and physical trauma may coexist.
  • Unblocks the collaterals and promotes healing - later tradition extends He Huan Pi to sinew and bone recovery when tenderness, pain, and constrained circulation slow repair.
  • Relieves constraint gently rather than heavily sedating - especially valued when emotional symptoms are driven by stagnation, rumination, or sadness rather than strong heat or phlegm-fire excess.

Secondary Actions

  • May be used for Lung abscess and suppurative chest conditions in later formula traditions, reflecting its ability to relieve constraint while moving Blood and reducing swelling.
  • Because it is sweet and neutral, it is often integrated into longer emotional-support formulas more easily than strongly bitter sedative herbs.

Classic Formulas

  • Huang Hun Tang (黄昏汤) - a classical single-herb or bark-centered use of He Huan Pi recorded in Qian Jin Fang for Lung abscess and internal suppurative heat.
  • Modified Xiao Yao San-type prescriptions (逍遥散加减) - later clinical tradition often adds He Huan Pi when Liver constraint presents with depression, insomnia, or persistent emotional agitation.
  • Trauma and swelling formulas may combine He Huan Pi with Ru Xiang, Mo Yao, and other blood-moving herbs when emotional upset accompanies bruising or injury.

Classical References

  • Shen Nong Ben Cao Jing records He Huan Pi as bringing joy and easing constraint, the classical root of its enduring use for sadness, worry, and disturbed sleep.
  • Ben Cao Yan Yi Bu Yi and related later texts describe He Huan Pi as treating injury from falls, reconnecting sinews and bones, and reducing swelling after trauma.
  • Modern Me & Qi teaching materials preserve both sides of the tradition: He Huan Pi for emotional disorders and for physical injury with swelling or pain.

Modern Research

Active Compounds

  • Julibroside C1 and related julibrosides (triterpenoid saponins) - the best-known bark constituents linked with anxiolytic, antidepressant, and cytotoxic research
  • Quercitrin and related flavonoids (flavonoids) - contribute antioxidant and neuroprotective effects
  • Syringaresinol glycosides (lignan glycosides) - implicated in central nervous system activity and serotonin-related mechanisms
  • Pinoresinol-type lignans (lignans) - support anti-inflammatory and neuroactive research
  • Phenolic glycosides and polysaccharide fractions - broaden the bark's antioxidant and immunomodulatory profile

Studied Effects

  • Bark extracts showed anxiolytic-like effects in the elevated plus-maze in rats, and the response was linked to serotonergic signaling through 5-HT1A mechanisms (PMID 15464830)
  • A recent Hehuan flower-versus-bark review summarized traditional use, phytochemistry, antidepressant, anxiolytic, anti-inflammatory, and tissue-repair pharmacology for He Huan Pi specifically as the trauma-calming bark drug (PMID 36509253)
  • Albizia julibrissin preparations ameliorated insomnia-associated memory loss and modulated gut-microbiota and inflammatory pathways in experimental models, consistent with the herb's traditional sleep-calming reputation (PMID 31057652)
  • Broader species-level review literature also connects Albizia julibrissin to depression treatment through monoaminergic, BDNF, and HPA-axis regulation, aligning with the bark's traditional Shen-calming role.

PubMed References

Safety & Interactions

Cautions

  • Potential additive drowsiness is plausible when He Huan Pi is combined with sedative medications or other strong Shen-calming herbs, so monitor sensitive patients carefully
  • Use with caution in pregnancy when high doses are employed chiefly for trauma or blood-moving purposes rather than gentle emotional support
  • MSK page not found - drug interaction data not available from Memorial Sloan Kettering integrative medicine database

Conditions