Lei Wan
StarOmphalia lapidescens Schroeter
Traditionally used for
- Digestion
☯ TCM Properties
Kills Parasites; Topically for tinea infections
Traditional Chinese Uses
Lei Wan is the dried sclerotium of the fungus Omphalia lapidescens, one of the most reliable parasite-expelling agents in the Chinese materia medica. Bitter and cold (and considered slightly toxic), it enters the Stomach and Large Intestine channels and is used chiefly to kill intestinal worms, being especially valued for tapeworm, as well as hookworm and roundworm. Externally it is applied for tinea (ringworm) infections.
Critically, Lei Wan's anthelmintic action depends on a heat-labile protease that is destroyed by cooking, so it must NOT be decocted. It is taken as a raw powder (commonly around 5–9 g, or per source higher single doses for taeniasis), swallowed with cool or warm water, usually after meals. Because it is cold and mildly toxic, it is used short-term and cautiously in those with Spleen-Stomach deficiency.
Relationships
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Botanical Description
Lei Wan (雷丸) is the dried sclerotium of Omphalia lapidescens Schroeter (synonym Polyporus mylittae), a parasitic basidiomycete fungus in the Polyporaceae that develops on the roots of bamboo and certain broadleaf trees in southern China. The medicinal substance is the underground sclerotium — an irregular, rounded to ovoid mass 1–3 cm across, with a wrinkled, dark brown to blackish outer skin and a dense, firm, white to pale yellow interior with a granular, somewhat starchy texture. Sclerotia are excavated from the soil during summer and autumn, washed free of debris, and sun-dried. The substance is a fungus, not a higher plant, and has been used since antiquity for parasitic infestations; the active component is a heat-labile protease, so it is administered as a powder rather than in decoction.
Active Constituents
Lei wan thiol protease
Cysteine (thiol) protease, proteinConcentration: about 3% of the sclerotium; molecular weight around 16.8 kDa
This is the anthelmintic principle. It is a proteolytic enzyme with an activity optimum around 37 degrees C and pH 7.48, and it digests the tegument of tapeworms directly. Because it is a protein, its activity is a property of the intact molecule: anything that denatures it destroys the drug. Electron microscopy of treated parasites shows extensive necrosis of the cortical and parenchymal layers.
Lei wan metalloprotease
Metalloprotease, proteinConcentration: subunits of approximately 4 kDa
A second proteolytic component, with an optimum near 50 degrees C and pH 7.5 and markedly activated by calcium ions. It contributes to the same tegument-digesting action as the thiol protease and shares its heat lability.
pPeOp (purified Omphalia lapidescens protein)
Protein, approximately 16 kDaConcentration: isolated from the sclerotium by polyvinylpyrrolidone extraction
The protein studied for the fungus's antitumour rather than antiparasitic activity. In gastric and cervical tumour lines it arrests the cell cycle and suppresses migration. It has no bearing on the herb's traditional anthelmintic use.
S-4001 polysaccharide
beta-(1-3)-D-glucan with (1-6) branchingConcentration: total polysaccharide content of the sclerotium is about 2.3%; S-4001 has an average molecular weight around 1,183,000
A branched beta-glucan of the type common to medicinal fungi, associated with immunomodulatory rather than anthelmintic activity. Related fractions OL-1, OL-2 and OL-3 have been described, OL-2 being principally beta-(1-3)-D-glucan and OL-3 containing D-glucose, 2-acetamido-2-deoxy-D-glucose and D-glucuronic acid.
Lanostane-type triterpenoids and ergosteroids
Triterpenoid and steroidTen compounds of this class, including a new tetranorlanostane skeleton, have been isolated from the ethanol extract. One of the ergosteroids was cytotoxic to MDA-MB-231 breast and HGC-27 gastric cells with IC50 values of about 11 and 12 micromolar, acting through Bax/Bcl-2 shift and procaspase-3 downregulation. Again, this is the antitumour rather than the anthelmintic side of the fungus.
⚠ Drug Interactions
Boiling water and any decocted (tang) formula the herb is added to
The anthelmintic activity of Lei Wan resides entirely in two proteases, a 16.8 kDa thiol protease with an optimum at 37 degrees C and a metalloprotease with an optimum at 50 degrees C. A Chinese decoction is simmered at or near 100 degrees C for twenty minutes or more, which is far outside the working range of either enzyme and irreversibly denatures them. This is the mechanistic explanation for the long-standing rule that Lei Wan is never decocted but given as a raw powder, and it is one of the few places in the materia medica where the efficacy of a herb is wholly determined by how it is prepared rather than by how much is given.
Clinical note: Give as unheated powder swallowed with cool or lukewarm water, or as a capsule or tablet, on an empty stomach. Do not add it to a decoction packet, do not stir it into hot tea, and do not use a granule or extract that was produced by hot-water extraction unless the manufacturer documents retained protease activity.
Praziquantel and albendazole
Comparative work summarised in the 2024 review reports O. lapidescens preparations performing better than albendazole and comparably to praziquantel against cestodes, working by direct proteolytic destruction of the parasite tegument rather than by the neuromuscular or tubulin-directed mechanisms of the two drugs. The mechanisms are independent, so an additive effect is plausible, but no co-administration study exists.
Clinical note: There is no evidence of harm, but equally none of benefit from combining them. Where a conventional cestocide is indicated, use it on its own protocol rather than assuming the herb adds to it.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| powder (not for decoction) | 15–21 g | Daily | — | — | 中国药典 2020 monograph 【雷丸】【用法与用量】15～21g，不宜入煎剂，一般研粉服，一次5～7g，饭后用温开水调服，一日3次，连服3天。 【性味与归经】微苦，寒。归胃、大肠经。 — Matched to ChP by romanised drug name (pinyin 'Lei Wan' → 雷丸); the romanisation is unique across all 649 ChP monographs, and the match was cross-checked against this record's own TCM temperature. Quoted verbatim. |
Evidence Tier
Limited evidence · 2 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
2
0 verified · 2 unverified
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
pPeOp from Omphalia lapidescens Schroet induces cell cycle arrest and inhibits the migration of MC-4 gastric tumor cells
pPeOp at 30, 60 and 90 micrograms per millilitre reduced survival of MC-4 human gastric tumour cells dose-dependently, arrested them in S phase and inhibited migration in a wound-healing assay, with reduced cyclin D1, CDK1, CDK2, cyclin B, MMP-2 and MMP-9 expression. 5-Fluorouracil was the positive control. Cell-line data only.
Cytotoxicity of lanostane-type triterpenoids and ergosteroids isolated from Omphalia lapidescens on MDA-MB-231 and HGC-27 cells
Ten triterpenoids and ergosteroids, two of them new, were isolated from the ethanol extract of the sclerotium. The most active ergosteroid showed IC50 values of 11.33 and 12.28 micromolar against MDA-MB-231 breast and HGC-27 gastric cells and induced apoptosis via a raised Bax/Bcl-2 ratio and loss of procaspase-3.
⚠ Safety & Contraindications
Contraindications
It is not suitable for decoction because it contains protease, which is easy to lose efficacy if heated to 60°C. Its use is cautious in patients with worm’s accumulation and deficiency-cold of the spleen and stomach.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 199–202.
Historical Texts
Shen Nong Ben Cao Jing
Han dynastyBen Cao Gang Mu
Ming dynastyReferences
- Xu K, Wang L, He D. Research on the Action and Mechanism of Pharmacological Components of Omphalia lapidescens . International Journal of Molecular Sciences (2024) [DOI]
- Wang Y, Dai O, Peng C, Su HG, Miao LL, Liu LS, Xiong L. Polyoxygenated ergosteroids from the macrofungus Omphalia lapidescens and the structure-cytotoxicity relationship in a human gastric cancer cell line . Phytochemistry Letters (2018) [DOI]
- Chen Y, Fu Z, Xu Y, Chen Y, Pan P. pPeOp from Omphalia lapidescens Schroet suppresses the proliferation of cervical cancer HeLa cells via JAK/STAT3 signaling pathway . ScienceAsia (2022) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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