Chong Lou (Zao Xiu or Rhizoma Paridis)

What Is Chong Lou

Chong Lou also known as Zao Xiu, Qi Ye Yi Zhi Hua, or Rhizoma Paridis is the rhizome of Paris polyphylla var. chinensis or Paris polyphylla var. yunnanensis, which is a perennial herb belonging to the Lily family. It first appeared in <Shennong Ben Cao Jing> in the late Western Han Dynasty (around 100 BCE).

There are 24 species of this genus, which are distributed in tropical and subtropical regions of Eurasia.

Paris polyphylla var. chinensis often grows on hillsides, forest edges, or thickets at 1,800-3,200 meters above sea level. It is distributed in Southwest China, Bhutan, Vietnam, Nepal, and India.

Paris polyphylla var. yunnanensis often grows in forest edges or roadside at an altitude of 1,400-3,600 meters. It is distributed in Fujian, Hubei, Hunan, Guangxi, Sichuan, Guizhou, and Yunnan in China.

Paris polyphylla

In the autumn of each year, people gather the rhizomes of Paris polyphylla var. chinensis or Paris polyphylla var. yunnanensis, wash them with water, remove their impurities and fibrous roots, cut them into pieces, dry them in the sun, and make them into Chinese herbal medicines.

Chong Lou contains polyphyllin, diosgenin, trillin, gracillin, pennogenin, Protogracillin, daucosterol, β-sitosterol, stigmasterol, α-spinasterol, β-ecdysone, kaempferol, quercetin, vanillin, fatty acids, phenylpropanoids, sugars, and alkaloids.

According to the Chinese Pharmacopoeia, the medicinal nature of Chong Lou is slightly cold, with slight toxicity and bitter taste. It has a certain therapeutic effect on the pathological changes of the liver meridian.

In traditional Chinese medicine, Chong Lou is often used to clear heat and remove toxins, alleviate swelling and relieve pain, cool the liver and calm the mind, treat snake bites, bruises, epidemic encephalitis B, mumps, pharyngitis, appendicitis, mastitis, cervical erosion, and some skin infections. It is an important component of Gong Xue Ning Jian Nang.


  • Anti-oxidation, anti-tumor, and anti-myocardial ischemia.
  • Killing the leishmania and the dactylogyrus.
  • Regulating immunity and having sedative and analgesic effects.
  • Promoting platelet aggregation, inducing vasoconstriction, and stopping bleeding.
  • Reducing the damage of CCL4 to liver tissue and protecting the liver.
  • Relieving cough and asthma and inhibiting tracheal spasm caused by histamine spray.
  • Inhibiting sperm viability and reducing sperm survival rate.
  • Removing heat toxins and treating furuncles and carbuncles caused by heat toxins.
  • Relieving throat swelling and pain, treating mumps and pharyngitis.
  • Treating scrofula and subcutaneous nodules caused by the transformation of liver depression into the fire.
  • Cooling the liver and treating infantile convulsions.
  • Dispersing blood stasis and relieving bruises.
  • The topical application after mashing it can relieve skin redness, swelling and pain, and treat snake bites.
  • Inhibiting enterovirus 71, B3 Coxsackie virus, and influenza A virus.
  • Inhibiting dysentery bacilli, typhoid bacilli, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, hemolytic streptococcus, and meningococcus.


Clinically, it is often combined with some corresponding drugs to treat a variety of cancers, such as esophageal cancer, laryngeal cancer, rectal cancer, lung cancer, liver cancer, brain cancer, cervical cancer, and acute leukemia.

Side Effects

  • Chong Lou is poisonous, and its incubation period is about 1-3 hours.
  • Excessive use of it may cause nausea, vomiting, abdominal pain, diarrhea, dizziness, headache, and other poisoning reactions.
  • In severe cases, it may cause paleness, cramps, or difficulty breathing.

Precautions and Warnings

  • The dosage of Chong Lou should be controlled between 3-9g.
  • It can be made into decoctions or ground into powder for external use.
  • People who are allergic to Chong Lou should not take it.
  • Patients with no syndromes of excess heat should not take it.
  • Patients with a deficiency of primordial qi should not take it.
  • Patients with diarrhea should not take it.
  • Patients with hematemesis or nosebleeds should not take it.
  • Pregnant and breastfeeding women should not take it.
  • Children, the elderly, and the infirm should not take it.