Deng Xin Cao (Medulla Junci)

What Is Deng Xin Cao

Deng Xin Cao commonly known as Medulla Junci is the stem pith of Juncus effusus L., which is a perennial herb belonging to the family Juncaceae. It is a relatively practical and common Chinese herbal medicine, which first appeared in <Kaibao Bencao> (Materia Medica of the Kaibao Period) around 974 AD.

There are about 332 species of Juncus, which are mainly distributed in temperate and boreal regions of the world. Among them, only a few species are distributed in tropical regions. The relatively representative species among them is Juncus effusus L..

Juncus effusus L. commonly known as soft rush, or common rush is nearly cosmopolitan. They are native to Europe, Asia, America, and Africa and are now naturalized in Australia.

They are often found in moist areas such as wetlands, river banks, ditches, swamps, and wet pastures. They are considered an invasive weed in many places. It is the raw material for making tatami and can also be used as a food additive.

Juncus effusus

From late summer to autumn, people harvest the stems of Juncus effusus L., dry them in the sun, take out their pith, straighten them, tie them into small handfuls, cut them into pieces, use them directly, or carbonize them, and make them into Chinese herbal medicines.

Deng Xin Cao contains dehydroeffusol, dehydrojuncusol, 7-carboxy-2-hydroxy-1-methyl-5-vinylphenanthrene, 2,8-dihydroxy-1,7-dimethyl-5-vinylphenanthrene, 2,7-dimethoxy-1-methyl-5-vinylphenanthrene, 7-hydroxy-2-methoxy-1,6-dimethyl-5-vinylphenanthrene, dehydroeffusal, 5-hydroxymethyl-1-methylphenanthrene-2,7-diol, dehydrojuncuenin A~J, juncusin, effususins A~D, dijuncuenin A~K, 9,10-dihydrophenanthrenes, pyrenes, juncosides I~V, oleanic acid, cycloart-23Z-ene-3β,25-diol, β-sitosterol, β-daucosterol, 5α-spinasterol, 7-oxo-β-sitosterol, luteolin, nobiletin, quercetin, tricin, chrysoeriol, eriodictyol, glycerides, vanillic acid, p-hydroxybenzoic acid, methyl p-hydroxybenzoate, p-hydroxybenzaldehyde, caffeic acid, ferulic acid, emodin, balanophonin B, effususins G, quinones, polysaccharides, fatty acids, and some trace elements.

Generally, the white or yellowish-white and fragile Deng Xin Cao with a white cross-section is preferred.

According to the Chinese Pharmacopoeia, the medicinal nature of Deng Xin Cao is slightly cold, with a sweet and bland taste. It has a certain therapeutic effect on the pathological changes of the heart, lung, and small intestine meridians.

In traditional Chinese medicine, it is often used to clear heart fire, induce urination, and treat oliguria, difficulty and pain in micturition, dysphoria, insomnia, vomiting, diarrhea, oral ulcers, periodontal infection, sore throat, nosebleed, gastrointestinal bleeding, hemorrhoid bleeding, vaginal bleeding after induction of labor, prolonged lochia, thrombocytopenia, tonsillitis, herpes zoster, hyperthyroidism, mumps, epidemic hemorrhagic fever, trachoma, non-gonococcal urethritis, chronic glomerulonephritis, and gastrointestinal cold.

There are more than 50 kinds of traditional Chinese medicine prescriptions containing it, such as Ba Zheng He Ji, Zhen Zhu Niu Huang San, and Qi Xing Cha.


  • Anti-inflammation, suppressing the production of inflammatory mediators in LPS-stimulated RAW 264.7 cells and attenuating carrageenan-induced paw-edema in mice [1].
  • Anti-oxidation, scavenging DPPH free radicals and ABTS free radicals [2].
  • Clearing heat and inducing urination, treating oliguria, difficulty and pain in micturition, and stranguria due to heat.
  • Purging heat and clearing heart fire, relieving dysphoria and insomnia, and treating night crying in children caused by heart-heat.
  • Relieving sore throat and treating orolingual ulcer.
  • Inhibiting the proliferation of gastric adenocarcinoma AGS cells, lung cancer A549 cells, breast cancer MCF-7 cells, and cervical cancer HeLa cells [2, 3].
  • Its dihydrophenanthrenes and glycerides have good antialgal activity against Selenastrum capricornutum [4, 5].
  • Its ethanol extract has a certain bacteriostatic effect on Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis. In addition, its 9,10-dihydrophenanthrene has significant antibacterial activity against Rhizoctonia solani, Verticillium dahliae Kleb, Sclerotinia sclerotiorum, Gibberella saubinetii, Bipolaris zeicola, and Phytophthora parasitica, Bacterium paratyphosum B, and Micrococcus lysodeikticus [6].
  • Multiple experiments confirm that dehydroeffusol possesses anxiolytic and sedative properties and does not affect the general movement coordination of mice [7].
  • Dehydroeffusol prevents amyloid beta 1-42-mediated hippocampal neurodegeneration by reducing intracellular Zn2+ toxicity. It has the effect of preventing and treating Alzheimer’s disease [8].


  • It can be used in combination with Mu Tong (Caulis Akebiae), Qu Mai (Dianthi Herba), and Che Qian Zi (Semen Plantaginis), etc. to treat oliguria, difficulty and pain in micturition, and stranguria due to heat.
  • It can be used in combination with Mu Tong (Caulis Akebiae), Zhu Ye (Bamboo Leaf), and Zhi Zi (Fructus Gardeniae), etc. to treat dysphoria, insomnia, oliguria, and difficulty and pain in micturition.
  • It can be combined with Dan Zhu Ye (Lophatherum Gracile), etc. to treat night crying in children caused by heart-heat.
  • It can be used in combination with Xian He Cao (Agrimonia Pilosa), Tie Xian Cai (Acalypha australis), etc. to treat nosebleeds.
  • It can be used in combination with Jin Qian Cao (Herba Lysimachiae), Che Qian Cao (Plantago Asiatica), Yi Mu Cao (Leonurus Japonicus), Mo Han Lian(Eclipta prostrata), Huang Jing (Rhizoma Polygonati), Shan Yao (Rhizoma Dioscoreae), Gan Cao (Licorice Root), etc. to treat dysuria, stranguria, soreness and weakness of waist and knees, abdominal distention and pain caused by dampness-heat in the lower jiao, or deficiency in the spleen and kidney.

Side Effects

  • At present, there is no literature report that Deng Xin Cao has toxic effects, and no data is showing that taking it at the prescribed dose can cause serious adverse reactions.
  • Overdose of it may cause stomach pain, fatigue, pale complexion, or chills in the extremities.

Precautions and Warnings

  • The dosage of Deng Xin Cao should be controlled at 1-3g.
  • It can be made into decoctions, capsules, or medicinal liquors.
  • People who are allergic to Deng Xin Cao should not take it.
  • Patients with deficiency-cold in lower jiao should not take it.
  • Patients with a deficiency of heart qi should not take it.
  • People with weakness of the spleen and the stomach should not take it.
  • Patients with urinary incontinence should not take it.
  • Pregnant and breastfeeding women should take it under medical supervision.
  • Children, the elderly, and the infirm should take it under medical supervision.