Cang Er Zi (Fructus Xanthii)

What Is Cang Er Zi

Cang Er Zi commonly known as Fructus Xanthii is the mature fruit of Xanthium sibiricum, which is an annual herb belonging to the family Asteraceae. It is a commonly used Chinese herbal medicine, which first appeared in <Shennong Ben Cao Jing> in the late Western Han Dynasty (around 100 BCE).

There are about 30 species of Xanthium, which are mainly distributed in central and northern America, Europe, Asia, and northern Africa. Among them, Xanthium strumarium and Xanthium sibiricum are relatively common.

Xanthium sibiricum is commonly known as Cocklebur and is a common field weed. They often grow on plains, hills, low mountains, wilderness roadsides, and fields. They are widely distributed in China, Russia, Iran, India, North Korea, and Japan.

Xanthium sibiricum

In autumn every year, people gather the ripe fruits of Xanthium sibiricum, dry them, remove impurities, stir-fry them, and make them into Chinese herbal medicines.

Cang Er Zi contains atractylidin, carboxy atractylidin, 4′-dessulfo atractylidin, xanthain, caffeic acid, protocatechuic acid, cryptochlorogenic acid, ferulic acid, methyl chlorogenate, oleic acid, stearic acid, linoleic acid, palmitic acid, arachidic acid, linolenic acid, seventeen acid, caprylic acid, myristic acid, quercetin, rutin, kaempferol-3-glucoside, hyperoside, fermlononetin, emodin, chrysophanol, aloe-emodin, thymine, uracil, lignans, amino acids, and volatile oils.

Generally, the solid, oval or spindle-shaped, yellow-brown, or yellow-green Cang Er Zi with thorns is preferred.

According to the Chinese Pharmacopoeia, the medicinal nature of Cang Er Zi is relatively warm, with toxicity and a pungent and bitter taste. It has a certain therapeutic effect on the pathological changes of the lung meridian.

In traditional Chinese medicine, it is often used to disperse wind and cold, relieve stuffy nose, expel wind and dampness, relieve pain, and treat acute rhinitis, chronic rhinitis, allergic rhinitis, neurorhinitis, sinusitis, rheumatic arthritis, conjunctivitis, bronchial asthma, chronic bronchitis, chronic nephritis, proteinuria, acute dysentery, malaria, toothache, flat warts, rubella, urticaria, sores furuncle.

There are about 100 kinds of Chinese medicine prescriptions containing it, such as Qinzhi Biyan Tangjiang, Bi Yuan Shu capsules, and Tong Qiao Biyan Pian.


  • Anti-inflammation, inhibiting xylene-induced ear swelling in mice.
  • Raising the pain threshold and reducing the number of writhing in mice caused by acetic acid.
  • Inhibiting hepatitis B virus and herpes simplex virus type I in vitro.
  • Inhibiting mouse anaphylactic shock caused by compound 48/80 and skin allergies caused by ovalbumin.
  • Inhibiting nuclear factor-κB activation, reducing cytokine-induced islet β cell damage, and repairing the function of pancreatic β cell.
  • Inhibiting the activity of α-glucosidase and reducing the blood sugar level of diabetic rats induced by streptozotocin.
  • Reducing the expression of lipogenic genes, increasing the expression of lipolytic genes, improving lipid accumulation, and reducing liver triglyceride content.
  • Dispersing wind and cold, treating fever, aversion to cold, head and body pain, nasal congestion, and runny nose caused by wind-cold.
  • Relieving stuffy nose, and treating anosmia, runny nose, rhinitis.
  • Expelling wind and dampness, treating rheumatic arthralgia and limb spasms.
  • Inhibiting Staphylococcus aureus, pneumococcus, Pseudomonas aeruginosa, Bacillus anthracis, Streptococcus beta, and Bacillus diphtheria.
  • Inhibiting the proliferation of lung cancer A549 cells, human gastric cancer MKN-45 cells, and human breast cancer MDA-MB-231 cells.
  • Experiments show that its ethyl acetate and ether extracts have immunosuppressive effects on the mononuclear macrophage immune system and mouse cellular immunity.


Side Effects

  • Cang Er Zi is poisonous, and its toxic ingredients are toxic proteins, sesquiterpene lactones, and water-soluble glycosides.
  • The main reasons for the poison are overdose of it and unqualified concocted Cang Er Zi. If the following conditions occur, stop using it immediately and seek medical attention.
  • Toxic reactions include dizziness, headache, general malaise, nausea, vomiting, coffee stains, mild abdominal distension, diarrhea, constipation, irritability, fatigue, lethargy, thirst, or oliguria.
  • In severe cases, it may cause coma, obsessive convulsions, jaundice, hepatosplenomegaly, liver dysfunction, protein in the urine, respiratory failure, and renal failure.

Precautions and Warnings

  • The dosage of Cang Er Zi should be controlled at 3-10g.
  • It can be made into decoctions, pills, or medicinal liquors.
  • People who are allergic to Cang Er Zi should not take it.
  • Patients with a headache due to blood deficiency should not take it.
  • Pregnant and breastfeeding women should not take it.
  • Children, the elderly, and the infirm should not take it.