Air Potato (Dioscorea Bulbifera, Huang Yao Zi)

Dioscoreae bulbiferae RhizomaThe air potato, also known as Dioscorea bulbifera in scientific name and Huang Yao Zi in Chinese name, is a common Chinese herbal medicine. The medicinal uses of this edible herb are immeasurable but one of its greatest health benefits is its ability to fight cancer. Sun Simiao,the China’s “King of Medicine”, was a great physician who could cure various incurable diseases. He ever made a famous formula containing this ingredient that mainly treated the goiter and tumor, which at that time foiled all other physicians. As a matter of fact, today this formula still remains in use clinically and becomes one of the most convenient and effective solutions for this type of disease. Read on please if you are interesting in knowing more about this amazing herb and what this formula is.

What is air potato?

Medicinally it means the tubers of Dioscorea bulbifera L., a vine plant of Asian or African origin in the family Dioscoreaceae, or true yam family. However, in many tropical areas it is in the list of invasive species and considered an unwelcome weed. Hence, other names of it are Dioscorea Bulbifera Tuber, Tuber Dioscoreae, Rhizoma Dioscoreae Bulbiferae, Airpotato Yam Rhizome, dioscoreae rhizoma, Dioscoreae bulbiferae Rhizoma, dioscorea yam, dioscorea root, radix dioscoreae, etc. In China it is mainly produced in Hubei, Hunan, Jiangsu and other places. In terms of medicinal properties, the one harvested during autumn and winter is usually considered preferred. After the harvest, remove its leaves and fibrous roots, wash clean, slice, dry in the sun, and use it raw.

This is one of the most recognizable herbaceous perennial twining vines because of the obvious aerial bulbs. Tubers are solitary, spherical or conical, 3 to 10cm in diameter, and with dark black skin and dense fibrous roots. Stems are cylindrical, up to several meters long, green or purple, and glabrous. Inside the leaf axils there are spherical or ovoid bulbils that are purple brown. Air potato leaf is alternative. Ovate blade is wide heart-shaped, 7 to 22cm long and 7 to 8cm wide, and with caudate apex, broadly cordate base and entire margin. Flowers are unisexual and dioecious. Many small flowers, yellow and white and axillary, form the spica. Capsule is drooping, oblong, and with 3 membranous wings. The flowering period is from August to September and fruit period is from September to October. Main habitats are valley, river bank, roadsides or forest edges.

Basic chemical constituents are diosbulbin A, saponins, tannins and starch. Semi-dried air potato tuber contains sucrose 22.5%, sugar 0.69%, starch 2.5%, saponins, and tannins. Also it contains diosbulbin B, C and diosgenin.

Air potato benefits

As mentioned above, Sun Simiao ever created an effective air-potato recipe for the treatment of goiter and tumor. Later, he disclosed it in his medical book. Actually this prescription and directions are quite simple. Firstly, soak 500 grams of air potato yam into 1000 ml of the rice liquor, seal the bottle, heat it for a while, and serve after it cools down. In recent years, there were clinical reports that this soaked wine was ever used for the treatments of 7 cases of thyroid adenoma, 2 cases of thyroid cancer, and 4 cases of other thyroid enlargement. Among them, 3 were ineffective but the rest cases gradually vanished by more than 50%, namely the diameter of neck reduced by up to 25%. What’s more, 6 cases eliminated the symptoms and signs by 80% or even 100%. This shows that the dioscorea bulbifera wine does live up to its fame. Modern research has found that it also works for other tumors. And now let its pharmacology tell you with more air potato facts.

Modern pharmacological actions of dioscorea bulbifera

1. It has a certain therapeutic effect on goiter caused by iodine deficiency in animals;
2. Its decoction and alcohol extract inhibits isolated intestine, excites non-pregnant uterus, and stops bleeding;
3. Water extract in vitro has different degrees of inhibition on a variety of pathogenic fungi;
4. Its decoction and alcohol extract can directly inhibit cardiac muscle. And the latter showed stronger inhibition than the former.

Selected herbal remedies on tuber dioscoreae

The Chinese Materia Medica tells that it is bitter in taste and cold and slightly poisonous in properties. And it goes to two meridians of lung and liver. Chief functions cover removing stasis to cure goiter, clearing heat and removing toxicity, and cooling blood and hemostasis. Basic uses and indications include goiter and tumor, pharyngitis, carbuncles and boils, snakebite, tumor, hematemesis, nosebleed, pertussis, and lung-heat cough and asthma. Recommended dosage is from 3 to 9 grams in decoction, soaked wine, or powder.

1. Hai Yao San. From Zheng Zhi Zhun Sheng (Standard of Diagnosis and Treatments), this recipe combines Hai Zao (Sargassum Seaweed), Mu Li (Oyster Shell), etc. to cure provoked goiter.

2. Huang Yao Tang. From Sheng Ji Zhong Lu (The Complete Record of Holy Benevolence), the formula uses it with E Jiao (Donkey-Hide Gelatin) for chronic epistaxis.

3. Huang Yao Tang. From The Complete Record of Holy Benevolence, this prescription takes it alone for recurrent hematemesis.

4. Huang Yao Zi San. From Bian Que Xin Shu (Medical Understanding of Bian Que), it uses its powder alone for the treatments of acute laryngeal infection, swollen cheek and chin, and phlegm in chest and diaphragm.

Air potato side effects and contraindications

Though modern pharmacological studies confirm that air potato tuber is with multiple therapeutic effects, its adverse reactions occurred from time to time. That’s to say, its toxicity shouldn’t be overlooked clinically when it is used for the treatment of goiter. Regardless of this herb alone or compound preparation, overdose is equally bad. The common toxic symptoms include gastrointestinal reactions like vomiting, diarrhea, abdominal pain and others. And it may also cause some certain damage to the liver and kidney, or even blood clotting disorders. TCM wise, use it with caution in the cases of deficiency of spleen and stomach, hepatic insufficiency, and renal insufficiency.

4 thoughts on “Air Potato (Dioscorea Bulbifera, Huang Yao Zi)

  1. Sally Nason, PhD

    I read that these potatoes are actually very noxious and can cause many disturbing symptoms such as hallucinations, migraine-like headaches, etc.

    I am now thoroughly confused.

    Please comment. Thank you.

    1. admin Post author

      Huang Yao Zi (Rhizoma Dioscoreae Bulbiferae) is frequently used in the treatment of goiter, sore throat, and a variety of cancers in TCM. Admittedly, this is an herb with liver toxicity. That is why it should be prepared before the use.

      However, the toxicity can be reduced by preparation with wine and water steam with low heat. In addition, the dosage should be controlled as well in order to take advantage of its benefits while minimizing its side effects and toxicity.

      Clinically, the usual dosage of Airpotato Yam Rhizome is from 3 to 10 gram. According to statistics, the total dose of 600 to 100g, 30g daily, can make 53 percent of users suffer from poisoning symptoms and liver damage. That’s to say, the dose cannot be arbitrarily increased. And here is the matters needed your attention when air potato is used.

      1. This herb should be avoided by someone with history of hepatitis or liver dysfunction;
      2. It must be stopped once the users experience symptoms such as hard stools, abdominal pain, sore, swollen gums, and so on;
      3. Liver function test should be done regularly during the treatment of hyperthyroidism and other diseases. Stop it once the test shows something wrong.

      1. Saravanan

        Thanks for all the information. Can we consume air potatoes in our normal diet by frying, curry with boiled potatoes etc.
        Is there any different way to consume.



  2. Dr Latheef

    Air potato-aerial tuber (the one looks exactly like a potato, with a thick outer skin that can be peeled easily) has been used as a meat potato in Kerala traditional cuisine, especially by Muslims of Kerala, during their Ramzan fasting, for food in the evening after breaking fasting, for centuries though it is almost extinct in Kerala now because of lack of care. It tastes like meat and especially enhances its taste and meat taste when cooked with any meat. When the outer skin is removed (which is almost like a plastic filament), there will be dark green colour, and once it is cut the inner part is like a normal potato, light white or light yellowish white. This is not toxic at all. The toxicity reference is about those aerial tubers (of certain varieties if Dioscorea bulbifera) with dark brown or blackish outer colour. The real air potato which looks exactly like a potato, mostly round in shape and white outer skin (as explained above) has no real tuber that can be used, whereas it is the tuber of other D. bulbifera are used for eating and their dark coloured aerial tubers are used for germination only and not for eating, which may have some toxicity and after proper processing these my be used as medicine as specified in the above article.


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