Shan Yao

Rhizoma Dioscoreae, Chinese Yam


Oral, 5:1 concentrated extract: 3-6 grams/day.

Chemical Composition

Diosgenin; Dopamine; Allantoin; Abscisin II; Lysine; Threonine; Serine; Arginine; Aspartic acid; Histidine; Glutamic acid; Proline; Valine; Leucine; Glycine; Alanine; Isoleucine; Tyrosine; Phenylalanine; Methionine; Cystine; Mannose; Glucose; Galactose; Sodium oxide; Potassium oxide; Alumina oxide; Ferric oxide; Calcium oxide; Magnesium oxide; Dopamine; Catecholamine; Cholesterol; Ergosterol; Campesterol; Stigmasterol; b-sitosterol; Phytic acid; Cholestanol; Isofucosterol; Clerosterol; Lathosterol; Polypheno1oxidase; Batatasine hydrochloride; g-aminobutyric acid; (24R)-a-methyl cholestanol; (24S)-b-methyl cholestanol; (24R)-a-ethyl cholestanol; (24S)-b-methyl cholestanol; 24-methylene cholesterol; 24-methylene-25-methyl cholesterol cholest-8-(14)-enol; (24R)-a-methyl cholest-8(14)-enol; (24S)-b-methyl cholest-8(14)-enol; (24R)-a-ethyl cholest-8(14)- enol. (1) , (2) , (3) , (4) , (5) , (6) , (7) , (8)

Inorganic Chemicals

Ba, Be, Ce, Co, Th, Cr, Cu, Ga, Mn, Mn,Nb, Ni,P, Sr


Contraindicated for patients with excessive dampness, pathogenic factors of the excess type, and or food retention.


Hypoglycemic effects

Administration of Shan Yao decoction can lower the blood pressure of healthy mice. It has both preventive and therapeutic effects alloxan-induced diabetes induced in mice. (9)

Anti-aging effects

Shan Yao polysaccharides, injected i.p., can promote the activity of glutathione peroxidase, catalase, peroxide dismutase and cerebral Na/K-ATPase, decrease the activity of monoamine oxidase and the contents of lipids peroxide and lipofuscin. (10)

Effects on immunity

Experiments show that Shao Yao polysaccharides can significantly promote the cellular and humoral immune functions in mice. (11)

Increasing muscular endurance and anti-fatigue effects

Experiments show that Shan Yao extract has anti-fatigue effects and can enhance endurance and contractility of muscles. (12)

Effects on the activity of monoamine oxidase (MAO)

One experiment randomly divided mice into six groups and five of them were fed decoctions of the following herbs, respectively: control group (stilled water), Radix Rehmanniae Praeparata, Flos Chrysanthemi, Rhizoma Dioscoreae, Radix Achyranthis Bidentatae, and a mix of all four herbs. The sixth group was fed distilled water and served as the comparison group. The herb decoctions were fed to the subjects twice a day, 0.15ml each time. Forty days later, the mice were killed, and their brains removed to determine the activity of MAO in the mitochondria. The results showed that, the MAO activity levels of the Rhizoma Dioscoreae and Radix Achyranthis Bidentatae groups were significantly lower than that of the comparison group (P£¼0.05), and that the difference between the MAO activity of the mix group and that of the comparison group was even more significant (P

Effects on the synthesis of monoamino transmitters

Administered at high dosages, Shao Yao can significantly increase the NE and 5-HT levels in the brains of reserpine-treated mice, suggesting that the herb promotes the synthesis of mono amino transmitters in animals treated with reserpine. (13)

Effects on the gastric system

Shan Yao can increase gastric secretion and gastric acidity. It has anti-diarrhea effects in mice wtih spleen deficiency. It can increase cold tolerance, but does not significantly affect the activity of pepsin in rats. (14)


  1. Wang Ben Xiang (ed). Modern TCM Pharmacology. Tianjin: Science and Technology Press; 1997.
  2. Editorial Committee of Chinese Materia Medica. State Drug Administration of China. Chinese Materia Medica. Shanghai: Science and Technology Press; 1998.
  3. Jiangsu College of Modern Medicine. Dictionary of Chinese Materia Medica, vol. I. Shanghai: People’s Press; 1986.
  4. Xu Li, et al. Methodology for Analyzing Active Components of Chinese Materia Medica. Beijing: People’s Health Press; 1984.
  5. Tang Shi Rong, et al. Traditional Chinese Medicine Bulletin. 1987;(4):36.
  6. Kang Yue Yu et al. Traditional Chinese Medicine Bulletin. 1988;13(7):37.
  7. Yan Su Qing, et al. Journal of Henan Medical University. 1990;25(1):36.
  8. Zhang Guo Wen, et al. Journal of Trace Elements and Health Research. 1998;15(2):44-45.
  9. Zhang Hong, et al. Journal of Shizhen Medicinal Material Research. 1997;8(1):71-72.
  10. Yan Tong, et al. Journal of Pharmacy Research. 1999;23(6):356-360.
  11. Miao Ming San. Henan Journal of TCM. 1996;16(6):349-50.
  12. Zhang Nan, et al. China Journal of Sports Medicine. 1996;15(2):114-117.
  13. Cheng Jing Xiu, et al. China Journal of Chinese Medicine. 1998;23(11):693-694.
  14. Li Qi Hua, et al. Journal of Traditional Chinese Medicine Material. 1999;22(11):587-588.