Qing Hao

Artemisia Annua

Chemical Constituents

Alpha-thujone, Beta-thujone, cineole, camphor, germacrene, cadinene, alpha-terpineol, camphene, pinene, myrcene. [3]

Dosage

Six to twelve grams of dried herb. [1]

Pharmacology

Pre-clinical

Traditional Use

A. Annua’s taste is considered bitter and pungent. Its properties are cold and remove fever. It works with the kidney, liver and gallbladder channels. It has long been used as an anti-parasitic in treatment of malaria and for treating the chills and fevers associated with malaria. As a cold herb, it is used to treat inflammation from various causes. [4] Qing Hao is often used to clear heat because its use does not disturb Qi, yin or blood in any marked way. [5]                           

General 

Antispasmodic activity: 

Laboratory studies have found constituents in A. Annua to have antispasmodic activity, supporting its traditional use in stomach or intestinal cramping. [6] 

Anti-microbial activity: 

Laboratory studies also support the traditional uses of A. Annua as an antibacterial and antifungal agent. [7] [8] 

Antioxidant activity: 

Essential oils found in A. Annua have been reported to have antioxidant activity in laboratory studies. [9] [10] 

Clinical

No documentation.

Interaction and Depletions

Interaction with other Herbs

No documentation.

Interaction with Drugs

No documentation.

Precautions and Contraindications

Side effects

Use only as directed by a trained practitioner. 

Thujone toxicity is well studied. The effects of excessive or prolonged ingestion of A. Annua include restlessness, vomiting, vertigo, tremor, convulsions and fatty degeneration of the liver. Collectively, these symptoms were formerly known as “absinthism” and were prevalent in the Paris café society absinthe drinkers of the late 19th century.

Pregnancy

Do not use Qing Hao in pregnancy and lactation. Thujone compounds are reported to be abortifacient and emmenagogic.

Age limitation

Not to be used by children. [4]

Adverse reaction

In general, Artemisia Annua is considered safe when used as recommended. [2] The LD50 of artemisinin in mice was 4228mg/kg. [1] Thujone, a constituent of A. Annua is considered toxic in high or extended levels.  

References

  1. Z. You-Ping. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Florida:CRC Press;1998.224.
  2. J.T. Mukinda, J.A. Syce. Acute and chronic toxicity of the aqueous extract of Artemisia afra in rodents. J Ethnopharmacol. 30May2007;112(1):138-144.
  3. W.B.E. Van, M. Wink. Medicinal Plants of the World. Portland, OR:Timber Press; 2004.
  4. Z. You-Ping. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Florida:CRC Press;1998.352-353. 
  5. D. Bensky, S. Clavey, E. Stoger, A. Gamble. Chinese Herbal Medicine Materia Medica, 3rd Edition. Seattle WA:Eastland Press;2004.30.
  6. A. Mulatu, Y. Mekonnen. Spasmolytic effects of artemisia afra and artemisia rehan in tissue preparations. Ethiop Med J. Oct2007;45(4):371-376.
  7. T. Rabe, S.J. Van. Antibacterial activity of South African plants used for medicinal purposes.J Ethnopharmacol. Mar1997;56(1):81-87.
  8. M. Gundidza. Antifungal activity of essential oil from Artemisia afra Jacq. Cent Afr J Med. Jul1993;39(7):140-142.
  9. M. Burits, K. Asres, F. Bucar. The antioxidant activity of the essential oils of Artemisia afra, Artemisia abyssinica and Juniperus procera. Phytother Res. Mar2001;15(2):103-108.
  10. E. Graven. Antimicrobial and antioxidative properties of the volatile (essential) oil of Artemisia afra Jacq. Flavour and Fragrance Journal .1992;7: 121-123.