Zao Jiao Ci (Spine of Chinese Honeylocust Fruit)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Zao Jiao Ci?

  The Sacred Lotus record carries a published reference range of 3–10 grams in decoction, with a slightly narrower 3–9 grams also recorded — an ordinary herb dose, and several times larger than the 1–1.5 grams recorded for the pod of the same tree. The difference between those two figures is the single most useful safety fact about this plant, and it is why the two entries must not be treated as one herb.

  • Why the thorn tolerates a larger dose. The thorn and the pod have measurably different chemistry. An analytical comparison across the three medicinals from this species found flavonoids concentrated in the thorn (0.54–2.38 mg/g, against 0.08–0.32 mg/g in either fruit), while the alkaloids ran overwhelmingly in the mature pod. The saponin load that makes the pod slightly toxic is not the thorn’s dominant profile.
  • In formula. Our one linked formula uses 3 grams — the lower end of the range — within a twelve-ingredient prescription rather than alone.
  • Not a self-treatment herb. The conditions it addresses are deep-seated infections of the skin and soft tissue. Those need clinical assessment, and in the modern setting frequently need antibiotics or drainage. Nothing here is a substitute for that.

  Sources: Sacred Lotus recorded reference ranges for the thorn (3–10 g; 3–9 g) and for the pod (1–1.5 g), and linked formula record; PMID 37282966, DOI 10.19540/j.cnki.cjcmm.20221228.201 (flavonoid and alkaloid content compared across thorn, mature pod and undeveloped pod). Reference literature only — not a prescription or self-use instruction.

Chinese Herb Contraindications & Cautions

• Are there cautions for Zao Jiao Ci?

  Yes — two specific ones are recorded in our own data: it is contraindicated in pregnancy, and it is not used once a sore has already opened. The second is not a general safety warning but a precise statement about timing: the herb’s job is to bring an unruptured swelling to a head, so once pus is already discharging there is nothing left for it to do and its blood-invigorating action becomes counterproductive.

  • Pregnancy. Contraindicated here, as it is for the pod of the same tree. Blood-invigorating, clump-dispersing herbs are avoided in pregnancy as a class, and the shared caution across both plant parts is worth noting given how different they otherwise are.
  • Open or already-suppurating sores. Recorded in our data as a contraindication. The traditional teaching pairs this with the qualifying phrase in the action itself — “prior to suppuration.”
  • Deficiency without excess. As with the wider category, the herb addresses an excess pattern; where a sore is failing to heal from depletion rather than obstruction, forcing it open is the wrong direction.
  • Modern context. Deep abscesses, cellulitis and carbuncles are potentially serious infections. This is a reference page about a traditional medicinal, not an alternative to medical assessment, drainage or antibiotics.
  • Not the same herb as the pod. Zao Jiao carries a much smaller dose ceiling, is flagged slightly toxic, and has an entirely different indication. The shared name is the trap.

  Sources: Sacred Lotus recorded caution list and herb identity for both plant parts; classical materia medica consensus on timing relative to suppuration, cross-referenced against multiple online sources. Neutral reference facts, not medical advice.

Chinese Herb Toxicity & Overdose

• Is Zao Jiao Ci toxic?

  Our record notes no toxicity for the thorn, and this is one of the places where our own data draws a distinction worth trusting: the pod of the same tree is flagged slightly toxic, the thorn is not. The analytical evidence supports the distinction rather than contradicting it — the thorn’s constituent profile is dominated by flavonoids, while the alkaloid content that characterises the mature pod is more than an order of magnitude lower in the thorn.

  • “No toxicity noted” is not the same as “studied and found safe.” We could not resolve a formal toxicology study of Gleditsiae Spina in the peer-reviewed literature, and we do not fill that gap with an inference. What exists is a long record of traditional use at ordinary doses, plus laboratory work that repeatedly describes thorn extract as active at concentrations that are not cytotoxic to normal cells.
  • Same species, different risk. Anyone reasoning from the pod’s haemolytic saponin toxicity to the thorn — or the reverse — will get it wrong. The plant-part distinction is the whole point of holding two entries.
  • The pregnancy caution stands regardless. Absence of a recorded toxicity note does not lift the contraindication documented in the cautions section above.

  Sources: Sacred Lotus recorded toxicity notes for both plant parts; PMID 37282966, DOI 10.19540/j.cnki.cjcmm.20221228.201 (alkaloid content an order of magnitude lower in the thorn than in the mature pod); PMID 25069874, DOI 10.3892/mmr.2014.2422 and PMID 26950116, DOI 10.3390/ijms17030328 (thorn extract active at non-cytotoxic concentrations in cell studies). Neutral reference facts, not medical advice.

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 Zao Jiao Ci (Gleditsiae Spina)?

  Yes — and unlike the pod, whose research is almost entirely about saponins, the thorn’s literature is built around flavonoids. A quantitative study across the three medicinals from this species found eight flavonoids at 0.54–2.38 mg/g in the thorn, several times their level in either fruit, and a widely targeted metabolomics survey identified 728 putative metabolites in the thorn, with flavonoids, phenolic acids, lipids, amino acids and organic acids as the main groups.

  • Antitumour and antimetastatic work. An ethanol extract of the thorns and its active constituent cytochalasin H inhibited tumour growth in a xenograft model without significant toxicity, and the authors reported repeated antitumour and antimetastatic effects across animal models. A separate study found that non-toxic concentrations of a water extract selectively blocked collagen-based migration of prostate cancer cells by suppressing α2 integrin expression and focal adhesion kinase phosphorylation, and that oral administration reduced xenograft tumour size.
  • Vascular effects. Ethanol extract of the thorns inhibited DNA synthesis, migration and invasion in growth-factor-stimulated vascular smooth muscle cells through G1-phase cell-cycle arrest and suppression of matrix metalloproteinase-9, again at concentrations without cell toxicity.
  • Immunomodulation. A 2025 study optimised extraction of the total flavonoid fraction, identified its principal components by high-resolution mass spectrometry, and evaluated it in an immunosuppression model — the first systematic work on the extraction chemistry of this fraction.
  • Quality control and authentication. A tandem mass-spectrometry method quantifies eight flavonoids in Gleditsiae Spina in under thirteen minutes and establishes criteria for telling genuine material from adulterants; rutin, isoquercitrin and quercitrin were reported in the thorn for the first time in that work. Metabolomic profiling has additionally shown that the thorn’s outer skin, wood and pith are chemically distinguishable, which has implications for how the material is processed and graded.

  Context. This is preclinical pharmacology, in cell culture and animals. It does not test the traditional indication — discharging pus from unruptured sores — and it is not evidence of clinical effect in people.

  Sources: PMID 37282966, DOI 10.19540/j.cnki.cjcmm.20221228.201; PMID 35000209, DOI 10.1002/bmc.5331; PMID 26027832, DOI 10.1248/bpb.b14-00647; PMID 26950116, DOI 10.3390/ijms17030328; PMID 25069874, DOI 10.3892/mmr.2014.2422; PMID 40204053, DOI 10.1016/j.fitote.2025.106524; PMID 29316281, DOI 10.1002/jssc.201701249; PMID 26643065, DOI 10.1016/j.jep.2015.11.044. Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Zao Jiao Ci different from Zao Jiao, and what about Zhu Ya Zao?

  Zao Jiao Ci (the thorn), Zao Jiao (the mature pod) and Zhu Ya Zao (a small undeveloped pod) are three distinct medicinals harvested from one tree, Gleditsia sinensis Lam. Both entries we hold sit in the same category here — Warm Herbs that Transform Phlegm-Cold — but that shared label conceals almost complete divergence in channel, dose, toxicity and use.

  • The thorn (this page) — spicy, warm, not flagged toxic; Liver and Stomach channels; reference dose 3–10 g; used to discharge pus and open unruptured sores; appears in Xian Fang Huo Ming Yin.
  • The pod (Zao Jiao) — spicy, warm, slightly toxic; Lung and Large Intestine channels; reference dose 1–1.5 g; used to dislodge phlegm forcibly and to open the orifices in phlegm-type collapse; appears in the emergency powder Tong Guan San.
  • The undeveloped pod (Zhu Ya Zao, Gleditsiae Fructus Abnormalis) — the Sacred Lotus does not hold a separate entry for it, a genuine gap flagged here for the site editor. Its interchangeability with the mature pod has long been contested: a fingerprinting study found the saponin aglycone content of the two fruits similar but their chromatographic profiles distinctly different, and concluded that swapping one for the other requires specific caution.

  The chemistry confirms the traditional split. A single analytical study measured ten constituents across all three medicinals and found the flavonoids concentrated in the thorn and the alkaloids in the mature pod, by more than an order of magnitude in each direction. Separate work using widely targeted metabolomics identified 728 putative metabolites in the thorn alone — dominated by flavonoids, phenolic acids, lipids and amino acids — and showed that even the thorn’s outer skin, wood and pith differ measurably from one another. Analytical methods have also been developed specifically to distinguish genuine thorn material from its commercial adulterants.

  The soap connection. The Chinese name element 皂 (zào) means soap: the pods are rich in triterpenoid saponins, lather in water, and were long used as a washing agent as well as a medicine. Our own record for the pod preserves the trace of this in its translation, “Soap Thorn.” It is a concrete anchor for the whole family — the detergent behaviour and the medicinal irritancy are the same chemistry seen from two sides.

  Flagged, not corrected: our two entries spell the genus differently in their pharmaceutical Latin — “Gleditschiae Sinensis Spina” for the thorn and “Gleditsiae Sinensis Fructus” for the pod. Both spellings appear in older pharmaceutical literature and refer to the same genus, Gleditsia; the current convention in the research literature is Gleditsiae Spina. We have raised this for the site editor rather than editing the identity field.

  Sources: Sacred Lotus herb and formula records for both plant parts; PMID 37282966, DOI 10.19540/j.cnki.cjcmm.20221228.201; PMID 24451075, DOI 10.2478/acph-2013-0036; PMID 35000209, DOI 10.1002/bmc.5331 (728 metabolites profiled across epidermis, xylem and pith of Gleditsiae Spina); PMID 29316281, DOI 10.1002/jssc.201701249 (flavonoid criteria for distinguishing Gleditsiae Spina from adulterants); PMID 26643065, DOI 10.1016/j.jep.2015.11.044. Reference information only.