Chinese yam

Chinese Name: Shan yao
Medical Name:
Latin Name: Dioscorea opposita thunb
Taste: Sweet and mild

Quotes from Chinese historical sources

THE HERBAL CLASSIC OF SHEN-NONG: "It is sweet and mild in flavour. It is used mainly to cure internal injuries, countering deficiencies of energy and of physical strength, subduing fevers caused by wind-evils, nourish the internal organs, benefitting physical strength, and developing the muscles."

OTHER CLASSIFIED RECORDS OF FAMOUS DOCTORS: "Mild and not poisonous. Treats feverish colds and the excess fluid they create, dizziness of eyes, promotes qui flow, relieves backaches, counteracts deficiencies of energy and strength in the internal organs, alleviates tiredness arising from fevers, strengthens the Yin-energy."

OPINIONS ON THE PROPERTIES OF HERBS: "Can heal the five impairments (of heart, liver, spleen, lung and kidney) and the seven damages, disperse chills, relieve backaches, ease the mind, soothe the soul, remove obstacles from the heart channel, benefit memory, and invigorate the heart when its energy has become depleted. Use it in cases of physical weakness."

RI HUA ZI MATERIA MEDICA: "Helps the five impairments (of heart, liver, spleen, lung and kidney) and seven damages, strengthens the muscles, enhances self-confidence, calms the nerves, subdues nocturnal emission, counters absentmindedness."

Western Research

Nat Prod. 2005 Aug;68(8):1259-61
Neuroprotective and antioxidant activity of compounds from the aerial parts of Dioscorea opposita.
Ma C, Wang W, Chen YY, Liu RN, Wang RF, Du LJ.
Laboratory of Pharmaceutical Sciences, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, People's Republic of China.
Bioactivity-guided fractionation of an ethanol extract of the aerial parts of Dioscorea opposita afforded a new compound, 6,7-dihydroxy-2-methoxy-1,4-phenanthrenedione (1), and four known compounds, chrysoeriol 4'-O-beta-D- glucopyranoside (2), chrysoeriol 7-O-beta-D-glucopyranoside (3), alternanthin (4), and daucosterol. The structure of 1 was established on the basis of the interpretation of its 1D and 2D NMR spectrascopic data. Compounds 1-4 exhibited both promising neuroprotective effects and discernible to moderate antioxidant activities in vitro.