Dioscorea polystachya, Shan Yao 山药

Chinese Yam
Shan Yao (TCM)
Picture
Picture D. alata
Descourtilz, Flore médicale des Antilles, 1829

Picture Dioscorea polystachya
(Photo by James H. Miller) (Wikimedia)

Botanical name:


Dioscorea spp.
  1. D. polystachya is the standard species.
  2. D. opposita
  3. Also used are D. persimilis, D. alata, D. fordii, D. batatas

Parts used:


Rhizome

Temperature & Taste:


Neutral, slightly moist. Sweet

Uses:


1. Tonifies Spleen and Stomach:
-low energy, poor appetite, loose stool, spontaneous sweating
-tonic for the young and old; eaten as a health food in China
-“replenishes the Spleen and Stomach, stops diarrhea” (Li Shi Zhen)

2. Tonifies Lung Qi and Yin:
-chronic cough, wheezing

3. Tonifies Kidneys, Astringes Kidneys:
-Diabetes, Wasting and Thirsting Disorder (overlaps Diabetes)
-Urinary frequency, nocturnal Urination
-Spermatorreha, Leukorrhea
-“reinforces physical strength … and enhances male sexuality” (Shen Nong Ben Cao)
-“Long-term use brightens the eye and improves hearing”. (Shen Nong Ben Cao)
-“
enlightens one’s wisdom and enhances one’s memory”. (Zhen Quan)


Dose:


Decoction: 9–30 grams; when used alone or in extreme weakness and for Wasting and Thirsting (Diabetes-like disorders), up to 60–250 grams are used per day.
Powder: 3–10 grams
The fresh root is often added to Soups in China as a health tonic and biscuits are also made to support children’s health.

Main Combinations:


The 3 Kidney Medicines
Often Dioscorea Shan Yao is combined with Cornus Shan Zhu Yu and Rehmannia Shu Di Huang. This trio forms the basis of the most important formulas used to strengthen the Kidneys. Alone, they nourish Kidney Yin and are usually corrected with the addition of Poria Fu Ling, Alisma Ze Xie and Paeonia Mu Dan Pi (as in Liu Wei Di Huang Wan, ‘Rehmannia ‘). When combined with Cinnamon (Rou Gui) and Aconitum Fu Zi, it is called Shen Qi Wan (Kidney Qi Pill) and is used for Yang deficiency.

1. Spermatorrhea and Night-sweats with Kidney Yin deficiency, Dioscorea Shan Yao with Rehmannia Shu Di Huang and Cornus Shan Zhu Yu
2. Spleen and Stomach deficiency:
i. with poor energy and poor appetite, Dioscorea Shan Yao with Ginseng and Atractylodes Bai Zhu.
ii. with Qi stagnation, Dioscorea Shan Yao with Amomum Sha Ren, Aurantium Chen Pi
iii. with loose stool or diarrhea, Dioscorea Shan Yao with Poria Fu Ling, Atractylodes Bai Zhu, Coix Yi Yi Ren
iv. with Food Stagnation, Dioscorea Shan Yao with Massa Fermenta (Shen Qu), Chicken Gizzard Skin (Ji Nei Jin)
v. Weakness, fatigue, poor appetite, Loose stool from Spleen deficiency, Dioscorea Shan Yao with Atractylodes Bai Zhu and Poria Fu Ling (as in Sheng Ling Bai Zhu San)
3. Chronic Cough from Lung Qi and Yin deficiency, Dioscorea Shan Yao with Ophopogon Mai Men Dong and Schisandra Wu Wei Zi.
4. Chronic Cough with Lung Qi deficiency, Dioscorea Shan Yao with Codonopsis Dang Shen and Licorice
5. Leukorrhea:
i. with Blood, Dioscorea Shan Yao with Cuttlebone (Hai Piao Xiao), Madder (Qian Cao)
ii. Damp-heat with Spleen deficiency, Dioscorea Shan Yao with Phellodendron Huang Bai, Plantain seed (Che Qian Zi)
6. Diabetes:
i. Dioscorea Shan Yao with Astragalus Huang Qi (this has been researched, see here)
ii.

Major Formulas:


Liu Wei Di Huang Wan
Er Long Zuo Ci Wan
Ma Wei Di Huang Wan
Ming Mu Di Huang Wan
Qi Ju Di Huang Wan
Zhi Bai Di Huang Wan
Sheng Ling Bai Zhu San
Shen Qi Wan, Jin Gui Shen Qi Wan
You Gui Wan
You Gui Yin
Zuo Gui Wan
Zuo Gui Yin

Cautions:


Generally very safe and regarded as a Health Food.
Not used alone when there is accumulated Dampness in the abdomen.

Main Preparations used:



GENERAL / REVIEW:
A Frontier Review of Nutraceutical Chinese Yam
Composition and Physicochemical Properties of Three Chinese Yam (Dioscorea opposita Thunb.) Starches: A Comparison Study.
[Studies on chemical constituents of Dioscorea opposita].

PROCESSING:
Quantification of Chinese yam processing methods based on pyrolysis characteristics and its relation to Maillard reaction
[A comparative study on chemical constituents in different processed products of Dioscorea opposita].

COMBINATIONS:
Astragulus embranaceus (Fisch.) Bge-Dioscorea opposita Thunb herb pair ameliorates sarcopenia in senile type 2 diabetes mellitus through Rab5a/mTOR-mediated mitochondrial dysfunction.

ANTIOXIDANT:
Antifatigue effects and antioxidant activity in polysaccharide fractions from Chinese yam bulbils.
Effects of concentrations, temperature, pH and co-solutes on the rheological properties of mucilage from Dioscorea opposita Thunb. and its antioxidant activity.
The degradation, antioxidant and antimutagenic activity of the mucilage polysaccharide from Dioscorea opposita.
Antioxidant Chinese yam polysaccharides and its pro-proliferative effect on endometrial epithelial cells.

ANTI-INFLAMMATORY:
Structures and Anti-Inflammatory Evaluation of Phenylpropanoid Derivatives from the Aerial Parts of Dioscorea polystachya.
Phenanthrenes in Chinese Yam Peel Exhibit Antiinflammatory Activity, as Shown by Strong in Vitro Cyclooxygenase Enzyme Inhibition.

ANTI-FATIGUE:
Antifatigue effects and antioxidant activity in polysaccharide fractions from Chinese yam bulbils.

IMMUNOMODULATORY:
Structural characterization and immunomodulatory activity of a polysaccharide from Dioscotea opposita.
In Vitro Immunomodulation of the Polysaccharides from Yam (Dioscorea opposita Thunb.) in Response to a Selenylation of Lower Extent.
Immunomodulatory Activity of the Glycoprotein Isolated from the Chinese Yam (Dioscorea opposita Thunb).

CARDIOPROTECTIVE:
In Vivo Protective Effects of Diosgenin against Doxorubicin-Induced Cardiotoxicity.

ANTI-HYPERTENSIVE:
Aqueous extract of dioscorea opposita thunb. normalizes the hypertension in 2K1C hypertensive rats.

LUNG INJURY:
A sesquiterpene isolated from the stems and leaves of Dioscorea opposita thunb. Transforms the composition of immune cells through ERbeta in a mouse model of LPS-induced lung injury.

REGULATES GUT BIOME:
Dioscoreae Rhizoma starch improves chronic diarrhea by regulating the gut microbiotas and fecal metabolome in rats.

INSULIN RESISTANCE:
Dioscorea opposita reverses dexamethasone induced insulin resistance.
DIABETES:
Hypoglycemic Effect of Chinese Yam (Dioscorea opposita rhizoma) Polysaccharide in Different Structure and Molecular Weight.
Characterization and antihyperglycemic activity of a polysaccharide from Dioscorea opposita Thunb roots.

ANTI-OBESITY:
Anti-obesity effects exerted by Dioscorea opposita Thunb. polysaccharides in diet-induced obese mice.

DIARRHEA:
Dioscoreae Rhizoma starch improves chronic diarrhea by regulating the gut microbiotas and fecal metabolome in rats.
Chinese yam (Dioscorea opposita Thunb.) alleviates antibiotic-associated diarrhea, modifies intestinal microbiota, and increases the level of short-chain fatty acids in mice.

NEUROPROTECTIVE:
Neuroprotective effects of Dioscorea opposita on scopolamine-induced memory impairment in in vivo behavioral tests and in vitro assays.
Neuroprotective and antioxidant activity of compounds from the aerial parts of Dioscorea opposita.

COGNITIVE FUNCTION:
Effects of Dioscorea polystachya ‘yam gruel’ on the cognitive function of diabetic rats with focal cerebral ischemia-reperfusion injury via the gut-brain axis.
The ameliorating effects of the cognitive-enhancing Chinese herbs on scopolamine-induced amnesia in rats.

ANTI-PROGESTERONIC:
Molecular screening of Chinese medicinal plants for progestogenic and anti-progestogenic activity.

MENOPAUSAL SYNDROME:
A Novel, Stable, Estradiol-Stimulating, Osteogenic Yam Protein with Potential for the Treatment of Menopausal Syndrome.

ERECTILE DYSFUNCTION:
The cold-soaking extract of Chinese yam (Dioscorea opposita Thunb.) protects against erectile dysfunction by ameliorating testicular function in hydrocortisone-induced KDS-Yang rats and in oxidatively damaged TM3 cells.

TESTICULAR DYSFUNCTION:
A Protein from Dioscorea polystachya (Chinese Yam) Improves Hydrocortisone-Induced Testicular Dysfunction by Alleviating Leydig Cell Injury via Upregulation of the Nrf2 Pathway.

CANCER-RELATED FATIGUE:
Effects of the polysaccharides extracted from Chinese yam (Dioscorea opposita Thunb.) on cancer-related fatigue in mice.

ANTIMUTAGENIC:
The degradation, antioxidant and antimutagenic activity of the mucilage polysaccharide from Dioscorea opposita.

CANCER:
BREAST:
A lectin with highly potent inhibitory activity toward breast cancer cells from edible tubers of Dioscorea opposita cv. nagaimo.

CHEMOTHERAPY TOXICITY:
In Vivo Protective Effects of Diosgenin against Doxorubicin-Induced Cardiotoxicity.