Ku Lian Gen Pi (China Tree Root Bark)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical reference dosage of Ku Lian Gen Pi?

  Materia medica references give roughly 4.5–9 g of the dried bark in decoction (or about 15–30 g of fresh bark), the root bark generally regarded as more potent than the stem bark. This is a published reference range, not a recommendation — because the herb is toxic, Chinese Pharmacopoeia and standard materia medica sources specify it is not to be used in excess of these ranges or for prolonged courses, and only under professional supervision.

  Source: Chinese Pharmacopoeia / standard materia medica dosage consensus (Bensky, Materia Medica, 3rd ed. and comparable references). Reference figure only — not a prescription or self-treatment instruction.

Chinese Herb Contraindications & Cautions

• Are there cautions for Ku Lian Gen Pi?

  Yes — Ku Lian Gen Pi is officially classified as a toxic herb in the Chinese Pharmacopoeia and is restricted to short, professionally supervised courses within published dose limits. Materia medica sources list it as contraindicated in pregnancy and in patients with liver disease or weak digestion, and caution against use in children and debilitated patients except under experienced supervision.

  • Pregnancy — contraindicated; anthelmintic/toxic-category herbs of this kind are traditionally avoided throughout pregnancy.
  • Liver disease — contraindicated, given documented hepatotoxicity of the bark's marker compound, toosendanin (see Toxicity and Research).
  • Dose and duration limits — not to be used above standard reference doses or for prolonged periods; this is the basis for its professional-supervision-only status.

  Source: Chinese Pharmacopoeia toxic-herb classification; materia medica consensus (Bensky/Chen & Chen cautions for toxic anthelmintic herbs). Neutral safety-reference framing, not usage instructions.

Chinese Herb Toxicity & Overdose

• Documented toxic herb. Cortex Meliae's marker limonoid, toosendanin, has repeatedly been shown in laboratory research to be hepatotoxic — damaging liver cells via disrupted autophagy/lysosomal function, altered energy metabolism, and oxidative/ferroptotic stress — which is the pharmacological basis for its contraindication in liver disease and for professional-supervision-only status.

  In excess it can also affect the heart and central nervous system: toosendanin acts as an agonist at cardiac L-type calcium channels (altering cardiac cell electrical activity) and is a well-characterized presynaptic neurotransmitter-release blocker at the neuromuscular junction and central synapses, effects consistent with the neurological and cardiovascular symptoms (weakness, numbness, ptosis, cardiovascular and GI disturbance) reported in documented human poisoning cases from the same plant genus.

  Note: the best-documented human poisoning case series (Phua et al., 2008) involved Melia azedarach rather than Melia toosendan specifically; both are recognized Cortex Meliae source species sharing toosendanin as the toxic marker compound, but species-specific human poisoning data for M. toosendan bark alone is sparser in the indexed literature. Included as directly relevant safety-reference context, with this caveat.

  Source: PMID 34000341 (Zhuo et al., Food Chem Toxicol 2021, hepatotoxicity biomarker/proteomics); PMID 36558960 (Luo et al., Pharmaceuticals 2022, TFEB-mediated lysosomal dysfunction); PMID 38460807 (Luo et al., Toxicol Lett 2024, STAT3/CTSC autophagy axis); PMID 15464064 (Li & Shi, Eur J Pharmacol 2004, cardiac L-type Ca2+ channel agonism); PMID 12378642 (Cui & He, World J Gastroenterol 2002, presynaptic neurotransmitter-release blockade); PMID 18763152 (Phua et al., Clin Toxicol 2008, human Melia azedarach poisoning case series). Public-safety reference facts explaining professional-supervision status — not a dosing guide.

• This herb is considered toxic.
  (while some Chinese herbs are toxic, it must be noted that many come prepared, or are combined, to mitigate their toxicity)

Herb-Drug Interactions

• No well-established clinical herb–drug interactions are documented in the literature reviewed. Given the demonstrated hepatotoxic mechanisms of its marker compound toosendanin (see Toxicity), practitioner awareness is reasonable when a patient is also taking other hepatotoxic medications or has impaired liver function — this is a precautionary inference from toxicology data, not a demonstrated clinical drug interaction. (Flagged for practitioner confirmation; not a substitute for professional review of a patient's full medication list.)

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Ku Lian Gen Pi (Cortex Meliae) and its marker compound toosendanin?

  Yes — toosendanin, the characteristic limonoid of Cortex Meliae bark, is extensively studied, mainly for its pharmacology and toxicology rather than for the traditional anthelmintic/topical indications directly. It was first isolated and characterized from Melia toosendan bark in the mid-20th century and remains the recognized quality-control marker compound for this herb.

  • Bark chemistry — phytochemical work has isolated additional meliacarpinin-type limonoids from Melia toosendan bark specifically, alongside toosendanin, supporting the traditional bark/root-bark use.
  • Anthelmintic/antiparasitic pharmacology — reviewed in the broader genus-Melia limonoid literature, consistent with the traditional roundworm/pinworm indication, though this reflects laboratory pharmacology rather than modern clinical trials.
  • Hepatotoxicity mechanisms — multiple recent studies converge on impaired autophagy/lysosomal function, disrupted hepatic energy metabolism, and oxidative/ferroptotic liver-cell damage as toosendanin's toxic mechanisms; reactive-metabolite protein adducts have been proposed as biomarkers correlating with injury severity.
  • Cardiac and neurological pharmacology — toosendanin has been shown to act as an agonist at cardiac L-type calcium channels and as a potent, long-lasting presynaptic blocker of neurotransmitter release (also studied for anti-botulinum-toxin activity), mechanisms that plausibly underlie cardiovascular and neurological effects reported in poisoning.
  • Human poisoning data — a clinical case series documents human poisoning from the related source species Melia azedarach, with neurological (weakness, numbness, ptosis), gastrointestinal, and cardiovascular effects; all reported patients recovered with supportive care. (See discrepancy note under Toxicity regarding species specificity.)

  Overall: strong laboratory/mechanistic evidence for both the traditional anthelmintic activity and the toxicity that restricts the herb's use; no modern human clinical trials of Cortex Meliae itself were identified.

  Sources: PMID 35140606 (limonoids of genus Melia, phytochemistry/pharmacology/toxicology review); PMID 30308969 (bark-specific limonoid chemistry of Melia toosendan); PMID 34000341; PMID 36558960; PMID 38460807 (hepatotoxicity mechanisms); PMID 15464064 (cardiac calcium-channel pharmacology); PMID 12378642 (presynaptic neurotoxic mechanism); PMID 18763152 (human poisoning case series, related species). Research context, not a therapeutic or safety claim.

Chinese Herb Notes

• How is Ku Lian Gen Pi differentiated from other anthelmintic herbs, and what formulas contain it?

  Among the "expel parasites" category, Ku Lian Gen Pi is notably more toxic than Bing Lang (Areca Seed) or Shi Jun Zi (Quisqualis), which is why materia medica sources reserve it for short, supervised courses rather than routine use. The root bark is traditionally considered stronger than the stem bark of the same tree.

  • Bing Lang (Areca Seed) — broad-spectrum anthelmintic (tapeworm, roundworm, fluke) with a milder toxicity profile; also moves qi and reduces stagnation.
  • Shi Jun Zi (Quisqualis Fruit) — anthelmintic favored in children for roundworm/pinworm because of its comparatively gentler action.
  • Ku Lian Gen Pi — a stronger, more toxic anthelmintic bark, used with more caution and typically not the first-line choice when a milder herb will serve.

  Formula context: the Sacred Lotus formula index links Ku Lian Gen Pi to Hua Chong Wan (Dissolve Parasites Pill), a classical parasite-expelling formula. (Traditional formula context, not treatment advice.)

  Botanical note: Cortex Meliae is sourced from the bark or root bark of Melia toosendan or the closely related Melia azedarach (chinaberry); both are recognized source species in the Chinese Pharmacopoeia and share toosendanin as the marker limonoid.

  Source: Sacred Lotus formula links; materia medica category differentiation (Bensky/Chen & Chen); PMID 35140606 (source-species and toosendanin marker-compound documentation).

This herb is considered toxic