Cicada molting (Chan Tui) is one of classic Chinese herbs for dispelling wind and heat from the body. In other words, it is capable of not only relieving exterior syndrome but also clearing heat.
What is cicada molting?
Cicada molting refers to the periodic shedding of the outer skin in cryptotympana pustulata Fabricius. They love perching on trees like poplar, willow, elm, and pagoda, etc. For medicinal purpose, they are usually collected during summer and autumn.
Cicada molt looks like living cicada, empty, slightly curved, about 3.5cm long, 2cm wide, yellowish-brown, semi-transparent, glossy, and with a pair of big prominent compound eyes on the head. And it contains plenty of chitin, protein, amino acid, and organic acid, etc.
What is cicada molt used for?
From the perspective of Traditional Chinese Medicine (TCM), it is sweet and cold in nature and covers meridians of lung and liver. Main functions are to dispel wind to promote eruption, relieve fever, relieve sore throat, remove nebula, and relieve spasm. Main uses and indications are wind-heat cold, sore throat, celostomia, unerupted measles, itching caused by rubella, red eye and slight corneal opacity, infantile convulsion, and tetanus. And usual dosage is 3 to 6 grams.
Lab studies have shown that cicada molt has medicinal effects as follows:
1. Anticonvulsant effect. Its medicinal liquor can prolong the average survival of rabbit suffering from experimental tetanus and alleviate the convulsions from tetanus. Besides, it can fight against the deadly seizures in mice induced by central stimulants like strychnine, cocaine, and nicotine, etc. By the way, in terms of anticonvulsant effect, the body part is better than the legs and head
2. Sedative action. It inhibits the spontaneous activity in mice and shows sedative action when used along with benzodiazepines;
3. Aritipyretic effect. The head and legs are better than the body.
Common compatibility of cicada shells
1. In the earliest days of warm disease, presenting fever and coughing, it often works with Bo He (Field Mint), Qian Hu (Hogfennel Root), and Niu Bang Zi (Great Burdock Fruit);
2. In the initial stage of measles refusing to erupt, it regularly combines with Ge Gen (Pueraria), Niu Bang Zi, Bo He, and Cheng Liu (Ramulus et Folium Tamaricis);
3. For redness and pain of the eye due to wind-heat attacking upward, it frequently joins Shi Jue Ming (Abalone Shell), Chi Shao (Red Peony Root), and Bai Ji Li (Caltrop Fruit) to dispersing wind and clear away heat;
4. For skin stinging and pruritus caused by nettle rash, it usually teams up with Fang Feng (Ledebouriella Root) and Bai Xian Pi (Dictamnus Root Bark).
Potential side effects and contraindications
39 mice, 6 each group randomly, had ever been chosen for acute toxicological experimentation to test different parts of cicada molting. 100% and 200% decoctions of different parts were slowly injected into the tail vein. As a result, there was no death after 24 hours. And there was still no death even after doubling the dose. All the facts show that cicada molt is rather safe to use.
TCM wise, Chan Tui should be avoided during pregnancy.