Chan Tui
StarCryptotympana pustulata Fabricius
Traditionally used for
- Eye health
- Nose & throat
- Cough & breathing
- Nerves & recovery
- Skin
Cautions & contraindications
- Pregnancy
☯ TCM Properties
Disperses Wind-Heat; Benefits the Throat and Restores the Voice; Vents Rashes and Stops Itching; Brightens the Eyes and Removes Visual Obstructions; Extinguishes Wind and Stops Spasms
Traditional Chinese Uses
Chan Tui (蝉蜕), Periostracum Cicadae, is the cast-off nymphal shell of the cicada Cryptotympana pustulata Fabricius, gathered from the ground and trees in summer. It is sweet and salty and cold, entering the Lung and Liver channels. It disperses Wind-Heat, benefits the throat and restores the voice, vents rashes and stops itching, brightens the eyes and removes visual obstruction, and extinguishes Wind to stop spasms.
Light and hollow, it acts at the surface and the upper body. It is the herb of choice for hoarseness or loss of voice from Wind-Heat and for sore, swollen throat, and it is used to bring out a measles rash that is slow to erupt and to settle the itching of urticaria and Wind rashes. It clears the eyes in Wind-Heat conjunctivitis with redness, tearing and superficial visual obstruction, and it is a gentle, traditional remedy for childhood night crying and fright, and for convulsive disorders including tetanus.
Its shell-shedding nature is held to explain its use for rashes and skin that must be released. It is mild, but as a Wind-dispersing herb it is used with caution in pregnancy.
Relationships
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Botanical Description
Chan Tui is not a plant but the dried cast-off exoskeleton (exuvia, or slough) shed by the nymphs of cicadas, principally Cryptotympana pustulata and related species in the family Cicadidae. After several years underground feeding on root sap, the final-instar nymph emerges, climbs onto a tree trunk or stem, and splits its old exoskeleton down the back to allow the winged adult to emerge; the empty cuticle remains clinging to the substrate and is collected as the medicinal material. The slough is a thin, fragile, translucent yellow-brown shell about 2-3 cm long, retaining the segmented body shape with intact head, prominent compound eyes, six clawed legs, and a longitudinal dorsal split (Wikipedia; NCBI).
Active Constituents
Chitin
AminopolysaccharideConcentration: Major structural component (~30-40% of the exuviae)
The dominant constituent of the cast-off exoskeleton, a large N-acetyl-glucosamine polysaccharide. As a high-molecular-weight polymer it is poorly absorbed; it contributes to the shell's structure and is unlikely to pass into breast milk in significant amounts.
N-acetyldopamine dimers (e.g. cicadadimers)
Catecholamine-derived dimersConcentration: Trace bioactive fraction
Characteristic dimeric N-acetyldopamine derivatives isolated from Periostracum Cicadae. They show anti-inflammatory and immunomodulatory activity, including regulation of Th1/Th17 differentiation, and are used as chemical markers for quality control.
Protein and free amino acids (aspartic acid, glutamic acid, proline, alanine, threonine, tyrosine, leucine, valine)
Proteins / amino acidsConcentration: High (protein is second most abundant fraction)
The shell is rich in structural protein and 17+ free amino acids embedded in the chitinous matrix, contributing to its nutritive and tonic properties in decoction.
Trace elements (calcium, zinc, copper, manganese, iron)
Inorganic mineralsConcentration: Trace
A range of mineral trace elements deposited in the exoskeleton; used together with organic markers in origin-authentication studies of Cicadae Periostracum.
Melanin / sclerotized pigment
Polyphenolic pigmentConcentration: Minor
Cross-linked catecholamine-derived pigment responsible for the brown coloration of the molt; contributes to antioxidant activity reported for the extract.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3–6 g | Daily | — | — | 中国药典 2020 【用法与用量】3～6g。 【性味与归经】甘，寒。归肺、肝经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Preparation Methods
Decoction (Tang)
Parts: Cast-off skin (exuviae) of the cicada
Typically 3-6 g of cleaned, dried molt is decocted in water. The legs and internal debris are usually removed and the shell rinsed of soil before use. Being light and dispersing, it is added toward the end and not cooked for long periods.
Powder
Parts: Whole exuviae
Dried molt is ground to a fine powder; small doses (often 1-3 g) are taken directly or added to formulas, particularly in pediatric practice for rashes, hoarseness and night crying.
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Disperses wind-heat and benefits the throat while nourishing and restoring the voice, for hoarseness and loss of voice.
Named pairing — Lü Jingshan, Shi Jinmo Dui Yao
Together they disperse wind-heat and ascend the clear, and extinguish wind to stop spasms, venting heat that is constrained in the upper body and skin.
Warm-heat epidemic disorders with constrained heat; also used for itching and throat swelling.
Core pair of a classical formula — Sheng Jiang San, Shang Han Wen Yi Tiao Bian (Yang Lixuan)
Evidence Tier
Limited evidence · 1 studyRecorded 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
1
1 verified · 0 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
Antiepileptic Effects of Cicadae Periostracum on Mice and Its Antiapoptotic Effects in H2O2-Stimulated PC12 Cells via Regulation of PI3K/Akt/Nrf2 Signaling Pathways
Cicadae Periostracum water extract prolonged the latency to convulsion and death in pentylenetetrazol-induced mice and reduced hippocampal neuronal damage. In H2O2-stimulated PC12 cells it improved cell viability and suppressed apoptosis by activating PI3K/Akt/Nrf2 signaling, providing a mechanistic basis for the traditional use in calming Liver-wind and stopping spasms.
Historical Texts
Ming Yi Bie Lu (Miscellaneous Records of Famous Physicians)
Han-Tang, c. 3rd-6th century CEBen Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty, 1578 CEReferences
- Zhang Q, Li RL, Tao T, Sun JY, Liu J, Zhang T, Peng W, Wu CJ. Antiepileptic Effects of Cicadae Periostracum on Mice and Its Antiapoptotic Effects in H2O2-Stimulated PC12 Cells via Regulation of PI3K/Akt/Nrf2 Signaling Pathways . Oxidative Medicine and Cellular Longevity (2021) [DOI]
- Xu M, Lee WS, Han J, Oh H, Park D, Tian G, Jeong T, Park H. Antioxidant and anti-inflammatory activities of N-acetyldopamine dimers from Periostracum Cicadae . Bioorganic & Medicinal Chemistry (2006) [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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