Shi Wei
StarPyrrosia lingua (Thunb.) Farw.
Traditionally used for
- Cough & breathing
- Urinary & fluids
☯ TCM Properties
Promotes Urination and Relieves Stranguria; Clears Lung Heat and Stops Cough; Cools the Blood and Stops Bleeding
Traditional Chinese Uses
Shi Wei (pyrrosia leaf) is a bitter, cool herb used in Chinese medicine to promote urination, clear Heat and Dampness from the Bladder, and stop bleeding. It is used for urinary tract infections, bloody urine, urinary stones, and urinary difficulty from Damp-Heat obstruction in the Bladder. Its hemostatic properties also address bleeding conditions, particularly hematuria. As an anti-inflammatory and diuretic herb with concurrent blood-stopping action, it is specifically valuable for conditions where Damp-Heat and bleeding coexist in the urinary system.
Western Herbalism Properties
Pharmacological Effects
- Antitussive: Concentrated decoction of P. sheareri leaf (oral) was antitussive in mice with SO2-induced cough; P. petiolosa decoction antitussive against ammonia-induced cough in mice.
- Expectorant: Oral or i.p. leaf extracts were expectorant in mice (phenol red method).
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 331.
Relationships
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Botanical Description
Pyrrosia lingua is an epiphytic or lithophytic evergreen fern in the Polypodiaceae family native to East Asia, growing on tree trunks, mossy rocks, and old walls in humid forests from southern China through Korea, Japan, Taiwan, and Vietnam. A long-creeping wiry rhizome 2-4 mm thick clad in narrow scales bears widely-spaced, simple, undivided fronds. Each frond consists of a slender wiry stipe and a thick leathery elliptic to lance-shaped lamina 5-25 cm long, dull green and sparsely hairy above and densely covered below with a soft fawn to rust-coloured felt of branched stellate scales — the feature giving the genus its common name 'felt fern'. Round to elongated sori are scattered or in rows across the underside of fertile fronds, sunk into the dense indumentum and lacking indusia.
Active Constituents
Chlorogenic acid
Caffeoylquinic acidConcentration: Mean 6998 micrograms per gram of dried leaf in Pyrrosia lingua in a 35-sample three-species survey, against 7728 in P. petiolosa and 4053 in P. sheareri. The Chinese Pharmacopoeia sets the limit for Pyrrosiae Folium at not less than 0.20 percent chlorogenic acid on the dried basis.
Chlorogenic acid is the pharmacopoeial assay marker for the leaf and the only major constituent whose level is similar across all three official Pyrrosia species. It carries much of the antibacterial and antioxidant activity of the crude drug, and its methyl ester is the compound most directly linked to the diuretic effect.
Mangiferin
Xanthone C-glycosideConcentration: Mean 68 micrograms per gram of dried leaf in Pyrrosia lingua, about one twelfth of the 853 micrograms per gram found in P. sheareri.
Mangiferin is often quoted as a signature constituent of Shi Wei, but the roughly tenfold species difference means that figure describes P. sheareri, not the P. lingua of this record. Any activity attributed to the mangiferin content of Shi Wei should be checked against which species was actually assayed.
Isomangiferin
Xanthone C-glycosideConcentration: Present at low levels in Pyrrosia lingua; P. sheareri averaged 1966 micrograms per gram, an order of magnitude higher.
The isomer of mangiferin, and like it strongly concentrated in P. sheareri rather than in P. lingua. It is used alongside mangiferin and chlorogenic acid as an authentication marker distinguishing the three official source species.
Astragalin
Flavonol glycoside, kaempferol 3-O-glucosideConcentration: Mean 571 micrograms per gram of dried leaf in Pyrrosia lingua, against 119 in P. sheareri, so the distribution runs opposite to that of the xanthones.
One of the two flavonol glycosides that are enriched in P. lingua and P. petiolosa relative to P. sheareri. Its inverse distribution against mangiferin is what makes a chromatographic profile, rather than a single marker, necessary to say which Pyrrosia is in the packet.
Trifolin
Flavonol glycoside, kaempferol 3-O-galactosideConcentration: Present in Pyrrosia lingua and P. sheareri; effectively absent from P. petiolosa.
Trifolin is the single most useful discriminator between P. petiolosa and the other two official species, because its absence from P. petiolosa is qualitative rather than a matter of degree. It is a marker of identity here rather than a constituent with an established action of its own.
Sibiricose A5 and 3-O-caffeoylquinic acid methyl ester
Caffeoylquinic acid derivativesConcentration: Isolated preparatively from Pyrrosia lingua leaf; not routinely quantified.
These two caffeoylquinic acid derivatives were isolated from P. lingua and shown to potentiate levofloxacin against uropathogenic Escherichia coli in vitro, suppressing YcgR expression and biofilm formation. They give a concrete chemical account of the drug's traditional use for stranguria with heat.
Methyl chlorogenate
Caffeoylquinic acid esterConcentration: Isolated from the ethyl acetate fraction of Pyrrosia petiolosa; not yet quantified in P. lingua.
Methyl chlorogenate inhibited the sodium-chloride cotransporter more strongly than hydrochlorothiazide in a cell assay and produced diuresis in rats. This is the clearest mechanism yet offered for the diuretic action of Shi Wei, but it was demonstrated in P. petiolosa, a different official species, and has not been confirmed in P. lingua.
⚠ Drug Interactions
Thiazide and loop diuretics
Shi Wei is dispensed specifically to promote urination. In Pyrrosia petiolosa, one of the three official source species, the ethyl acetate fraction produced diuresis comparable to hydrochlorothiazide in rats, and the isolated methyl chlorogenate inhibited the sodium-chloride cotransporter more potently than hydrochlorothiazide in a cell assay. That is the same molecular target as thiazide diuretics, so the effect is additive rather than independent. The work was done in P. petiolosa and not in the P. lingua of this record, but the two species sit in one clade and carry a similar caffeoylquinic acid profile.
Clinical note: In patients already on a thiazide or a loop diuretic, check potassium and sodium before starting and again after two weeks, and warn about postural dizziness. Be more cautious still in older patients and in anyone on an ACE inhibitor or ARB as well.
Lithium
Lithium is handled by the proximal tubule in parallel with sodium, and agents that cause sustained natriuresis and volume contraction reduce lithium clearance. Shi Wei has demonstrated diuretic activity in rodents and is prescribed for its diuretic effect. No study has measured lithium levels alongside this herb, so the concern is inferred from the mechanism rather than observed.
Clinical note: Avoid prescribing Shi Wei to a patient on lithium unless their prescriber is monitoring levels. If it is used, get a lithium level within one to two weeks of starting and after any dose change, and stop the herb if the patient becomes dehydrated or unwell.
Levofloxacin and other fluoroquinolones
Chlorogenic acid, sibiricose A5 and 3-O-caffeoylquinic acid methyl ester isolated from Pyrrosia lingua enhanced the antibacterial activity of levofloxacin hydrochloride against reference and clinical uropathogenic Escherichia coli in a concentration-dependent way, raised intracellular cyclic di-GMP, suppressed YcgR expression and inhibited biofilm formation. The effect is documented only in bacterial culture, with no human pharmacokinetic or clinical data.
Clinical note: This is a plausible favourable interaction, not a licence to reduce an antibiotic dose. Do not treat Shi Wei as a reason to shorten or lighten a course of fluoroquinolone for a urinary infection, and continue to follow culture and sensitivity results.
Non-official Pyrrosia species sold as Shi Wei
The Chinese Pharmacopoeia admits only three species as Pyrrosiae Folium: P. sheareri, P. lingua and P. petiolosa. Chinese market surveys identify Pyrrosia davidii, P. gralla, P. drakeana, P. martinii and P. calvata as the species commonly confused with or substituted for the official drug, and work on the chloroplast genomes of the three official species notes explicitly that ordinary DNA barcodes do not separate Pyrrosiae Folium from its adulterants, which is why five divergent regions had to be developed as markers. Dried Pyrrosia fronds of different species are hard to tell apart once cut.
Clinical note: Buy Shi Wei from a supplier who states the species and can produce a chlorogenic acid assay of at least 0.20 percent. Whole or large fragments of frond can be checked against the described leaf shape, stipe length and sorus arrangement; finely cut material cannot.
Pyrrosia sheareri supplied as Pyrrosia lingua
All three are official, so substituting one for another is legal, but they are not chemically equivalent. In a 35-sample survey P. sheareri carried roughly twelve times the mangiferin and an order of magnitude more isomangiferin than P. lingua, while P. lingua carried nearly five times the astragalin. Chlorogenic acid, the assay marker, is similar in all three, so the pharmacopoeial test does not detect the swap.
Clinical note: If a prescription depends on the profile of a particular species, name the species rather than relying on the pharmacopoeial name or assay. Where the literature you are relying on used P. petiolosa or P. sheareri, note that your dispensed P. lingua may not reproduce it.
Ptaquiloside-type illudane fern toxins from other fern taxa
Ptaquiloside, an illudane norsesquiterpene glycoside, is a DNA-alkylating carcinogen that occurs chiefly in Pteridium and has also been measured in Pteris species; its characteristic lesions in exposed cattle are urothelial. It has not been reported from Polypodiaceae, and no assay for it has been published for Pyrrosia. Shi Wei is a fern frond dispensed for long courses in exactly the urinary conditions this toxin class targets, so the absence of published screening is worth stating rather than reading as a clean result.
Clinical note: There is no evidence that Shi Wei contains ptaquiloside and none that it does not, because nobody has looked. Prefer bounded courses over indefinite daily use for chronic stranguria, and do not extend the drug to patients with a history of urothelial cancer without a specific reason.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 6–12 g | Daily | — | — | 中国药典 2020 【用法与用量】6～12g。 【性味与归经】甘、苦，微寒。归肺、膀胱经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Evidence Tier
Moderate evidence · 5 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
5
2 verified · 3 unverified
Show 5 studies
- Molecular mechanism of Pyrrosia lingua in the treatment of nephrolithiasis: Network pharmacology analysis and in vivo experimental verification
- Synergistic Effects of Pyrrosia lingua Caffeoylquinic Acid Compounds with Levofloxacin Against Uropathogenic Escherichia coli: Insights from Molecular Dynamics Simulations, Antibiofilm, and Antimicrobial Assessments
- Potential low toxic alternative for Na-Cl cotransporter inhibition: A diuretic effect and mechanism study of Pyrrosia petiolosa
- Ethanolic extract of Pyrrosia lingua (Thunb.) Farw. ameliorates OVX-induced bone loss and RANKL-induced osteoclastogenesis
- Antioxidant activity of herbal medicine Pyrrosia lingua evaluated by electron paramagnetic resonance spectroscopy
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
Molecular mechanism of Pyrrosia lingua in the treatment of nephrolithiasis: Network pharmacology analysis and in vivo experimental verification
Pyrrosia lingua powder and extract lowered urinary oxalic acid, urinary calcium and osteopontin in a rat kidney-stone model, with the extract performing better than the raw powder, and shifted faecal Oxalobacter formigenes, Bacteroidetes, Bifidobacterium and Faecalibacterium. Network analysis attributed the effect to quercetin and kaempferol acting through toll-like receptor signalling. This is a rat model with a computational component, and the reduction in Oxalobacter formigenes, an oxalate-degrading organism, is an unexplained finding that runs against the proposed mechanism.
Synergistic Effects of Pyrrosia lingua Caffeoylquinic Acid Compounds with Levofloxacin Against Uropathogenic Escherichia coli: Insights from Molecular Dynamics Simulations, Antibiofilm, and Antimicrobial Assessments
Three caffeoylquinic acids from Pyrrosia lingua, chlorogenic acid, sibiricose A5 and 3-O-caffeoylquinic acid methyl ester, were identified as YcgR binders by docking and then shown to potentiate levofloxacin hydrochloride against reference and clinical uropathogenic Escherichia coli, to raise intracellular cyclic di-GMP and to inhibit biofilm formation. Entirely a bacterial-culture and simulation study, with no animal or human component.
Potential low toxic alternative for Na-Cl cotransporter inhibition: A diuretic effect and mechanism study of Pyrrosia petiolosa
The ethyl acetate fraction of Pyrrosia petiolosa gave the strongest diuresis and urinary sodium excretion in rats, comparable to hydrochlorothiazide, with no toxicity seen in mice. Methyl chlorogenate isolated from it inhibited the sodium-chloride cotransporter more strongly than hydrochlorothiazide in cell assay and was diuretic in rats. Note the species: this is P. petiolosa, a co-official source of Pyrrosiae Folium but not the P. lingua of this record, and the finding has not been repeated in P. lingua.
Ethanolic extract of Pyrrosia lingua (Thunb.) Farw. ameliorates OVX-induced bone loss and RANKL-induced osteoclastogenesis
An ethanolic extract of Pyrrosia lingua suppressed RANKL-induced osteoclast differentiation in precursor cells by blocking NFATc1 induction through the aryl hydrocarbon receptor and c-Fos axis, and reduced trabecular bone loss and weight gain in ovariectomised mice. This is a use with no traditional precedent for the drug and rests on one rodent study, so it should not be presented to patients as an established indication.
Antioxidant activity of herbal medicine Pyrrosia lingua evaluated by electron paramagnetic resonance spectroscopy
Electron paramagnetic resonance spin-trapping was used to measure radical scavenging by Pyrrosia lingua extracts directly rather than through the usual colorimetric surrogates. It is a methodological and in vitro antioxidant characterisation of the species named in this record, with no bearing on clinical effect.
Historical Texts
Shen Nong Ben Cao Jing (Divine Husbandman's Classic of the Materia Medica)
Han dynasty, compiled by the 2nd century CEMing Yi Bie Lu (Miscellaneous Records of Famous Physicians), attributed to Tao Hongjing
Southern and Northern Dynasties, about 500 CEBen Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty, 1596References
- Xiao W, Peng Y, Tan Z, Lv Q, Chan CO, Yang J, Chen S. Comparative Evaluation of Chemical Profiles of Pyrrosiae Folium Originating from Three Pyrrosia Species by HPLC-DAD Combined with Multivariate Statistical Analysis . Molecules (2017) [DOI]
- Yang CH, Liu X, Cui YX, Nie LP, Lin YL, Wei XP, Wang Y, Yao H. Molecular structure and phylogenetic analyses of the complete chloroplast genomes of three original species of Pyrrosiae Folium . Chinese Journal of Natural Medicines (2020) [DOI]
- Fan Y, Feng H, Liu L, Zhang Y, Xin X, Gao D. Chemical Components and Antibacterial Activity of the Essential Oil of Six Pyrrosia Species . Chemistry and Biodiversity (2020) [DOI]
- Vetter J. The Norsesquiterpene Glycoside Ptaquiloside as a Poisonous, Carcinogenic Component of Certain Ferns . Molecules (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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