Zi Cao also known as Radix Arnebiae or Arnebia Root is the root of Arnebia euchroma or Arnebia guttata, which is a perennial herb belonging to the family Boraginaceae. It has a medicinal history of more than 2,000 years.
Arnebia euchroma often grows in mountains, grasses, dry stone slopes, valleys, and shrubs at an altitude of 2,500-4,200 meters. It is distributed in China’s Xinjiang, Tibet, Nepal, Pakistan, Afghanistan, Iran, and Russia. 70% of the world’s medicinal Zi Cao materials come from this species.
Arnebia guttata often grows in the Gobi, rocky mountain slopes and lakeside gravel lands at an altitude of 280-4,200 meters. It is distributed in Pakistan, Mongolia, Kashmir, India, Russia, Afghanistan, and China. It is not currently cultivated by artificial introduction.
Lithospermi radix is also called Zi Cao in China and is the root of Lithospermum erythrorhizon. It is a Chinese herbal medicine with various antiviral and biological activities. Earlier, it was used interchangeably with the Radix Arnebiae.
Every spring and autumn, people gather the roots of Arnebia euchroma or Arnebia guttata, remove their impurities, wash them with water, cut them into thick pieces, dry them in the sun, and make them into Chinese herbs.
Zi Cao contains shikonin, deoxyshikonin, acetylshikonin, propionylshikonin, isobutylshikonin, isovalerylshikonin, β-hydroxy isovaleryl shikonin, β，β’-dimethylacryloyl shikonin, α-methyl-n-butyryl shikonin, 3,4-dimethylpentene-3-acyl shikonin, alkannin, alkannan, phenolic acids, benzoquinones, fatty acids, alkaloids, and polysaccharides.
Generally, purple-red or purple-brown Zi Cao with thick skin, small woody core, and yellow-white or yellow cross-section is the best.
According to <Compendium of Materia Medica>, the medicinal property of Zi Cao is relatively cold, with a sweet and salty taste. It has a certain therapeutic effect on the pathological changes of the heart and liver meridians.
In traditional Chinese medicine, Zi Cao is often used to clear heat and cool blood, promote blood circulation and eruptions, remove toxin, treat eczema, pityriasis rosea, uterine erosion, urethral stricture, burns, hepatitis, oral mucosal disease, psoriasis, phlebitis, allergic purpura, refractory ulcer, suppurative otitis media, and vaginitis.
About 50 kinds of traditional Chinese medicine prescriptions contain it, such as Jing Wan Hong Ruan Gao, Bai Shi Wan, and Shengji Yuhong Gao.
Health benefits of Zi Cao
- Anti-inflammation, anti-allergy, and anti-fertility.
- Inhibiting lipid oxidation and scavenging free radicals.
- Inhibiting the expression of fat transcription factors and the accumulation of fat in cells.
- Inhibiting platelet aggregation and preventing atherosclerosis and thrombosis.
- Promoting the proliferation of T lymphocytes, enhancing the phagocytic function of peritoneal macrophages, and improving immunity.
- Reducing the acute liver injury induced by concanavalin A, D-galactosamine, or acetaminophen and protecting the liver.
- Clearing heat, treating purple-black macules, and rashes caused by warm-toxins.
- Promoting eruptions and relieving sore throat.
- Cooling blood, treating hematemesis and epistaxis caused by blood heat.
- Removing heat toxins, relieving skin swelling and pain, and treating sores and carbuncles caused by heat toxins.
- Promoting skin wound healing, treating skin ulcers, burns, and scalds.
- Inhibiting human papillomavirus, herpes virus, hepatitis B virus, HIV-1 virus, parainfluenza virus, and influenza A virus.
- Inhibiting the proliferation of MCF-7 breast cancer cells, HCC liver cancer cells, A549 lung cancer cells, prostate cancer cells, and AGS human gastric cancer cells.
- Inhibiting Staphylococcus aureus, Escherichia coli, Bacillus subtilis, typhoid bacillus, dysentery bacillus, Pseudomonas aeruginosa, hemolytic streptococcus, Proteus, Candida albicans.
- Studies have found that its decoction can excite the heart.
Zi Cao is used with other Chinese herbs
- It with Chi Shao (Radix Paeoniae Rubra), Chan Tui (Periostracum Cicadae), and Gan Cao (Licorice Root) can treat macules caused by warm-toxins.
- It with Niu Bang Zi (Fructus Arctii), Shan Dou Gen (Radix Sophorae Tonkinensis), and Lian Qiao (Fructus Forsythiae) can alleviate sore throat and treat measles.
- It with Huang Qi (Astragalus Root), Sheng Ma (Rhizoma Cimicifugae), and Jing Jie (Schizonepeta Tenuifolia) can treat the insufficient outbreak of measles.
- It with Jin Yin Hua (Flos Lonicerae), Lian Qiao (Fructus Forsythiae), and Pu Gong Ying (Dandelion) can treat sores and carbuncles caused by heat toxins.
- It with Huang Lian (Rhizoma Coptidis), Huang Bai (Cortex Phellodendri), and Lou Lu (Radix Rhapontici) can treat eczema.
Side effects of Zi Cao
Some studies report that it contains a variety of hepatotoxic alkaloids, which may cause liver damage.
Precautions of Zi Cao
- The dosage of Zi Cao should be controlled at 5-10g.
- It can be made into decoctions, pills, ointments, or mashed for external use.
- People with weakness of spleen and stomach should not take it.
- People with loose stools should not take it.
- Women who are pregnant or planning to become pregnant should not take it.