Zi Wan

Radix Asteris, Aster

Dosage

For oral usage, it is decocted with 4.5-10g, or made into pills or powder.

Chemical Composition

Shionone; Friedelin; Epifriedelanol; Stigmasterol; Friedel-3-ene; Aurantiamide acetate; b-sitosterol; b-amyrin; Carotene; Spinasterol; Stigmastanol; 3b-hydroxy-20,24-diene-dammarane; Stigmasterol-d7,22-diene-3b-palmitic acid ester; Suberone; D-suberone-14-ene-3-ol. (1) , (2) , (3)

Precautions

The herb should be taken with caution by patients with excessive heat.

Pharmacology

Expelling phlegm and relieving cough

Experiments show that Zi Wan can increase the excretion of phenol red from mice’s respiratory tract. Isolated from Zi Wan’s petroleum ether and ethyl acetate components, the monomers of shionone and epi-suberol have expectorant effects. (4) Research shows that Zi Wan of different geographical origins invariably has an anti-tussive effect. (5)

Effects on tracheospasm

Experiments show that Zi Wan inhibits histamine- and acetylcholine-induced tracheospasm in guinea pigs. The optimum concentration for this effect is 8.23mg/ml. (6)

References

  1. Lu Yan Hua, et al. The chemical composition of Zi Wan. Journal of Pharmacy University of China. 1998;29(2):97-99.
  2. Zhang Jia Ming, et al. The chemical composition of Huizhi Zi Wan (Aster poliothamnus Diels). Journal of Chinese Medicine. 1997;22(2):103-104.
  3. He Lan, et al. The chemical composition of Xiaoshe Zi Wan (Aster albescens). Journal of Chinese Medicine. 1996;21(8):483-484.
  4. Lu Yan Hua, et al. Zi Wan’s effect in expelling phlegm and relieving cough: the effective parts and active components. 1999;30(5):360-362.
  5. Zhao Xian Guo, et al. Zi Wan (III): A comparison of the herb’s expectorant and anti-tussive effects among different origins. Journal of Chinese Materia Medica. 1999;30(1):353-7.
  6. Li Yan, et al. The effect of Zi Wan and Gan Cao on the trachea in guinea pigs. Chinese Medicine Information. 1999;16(4):47.