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Family Dioscoreaceae
Ubi
Dioscorea alata
YAM

Mao shu

Scientific names Common names
Discorea alata L. Ube (Tag.)
Discorea atropurpurea Roxb. Ubi (Tag., Bis., Ilk.)
Discorea colocasiifolia Pax Kinampai (Bis.)
Discorea eburnea Lour. Greater yam (Engl.)
Discorea globosa Roxb. Purple yam (Engl.)
Discorea javanica Queva Ten-months yam (Engl.)
Discorea purpurea Roxb. Water yam (Engl.)
Discorea rubella Roxb. Winged yam (Engl.)
Discorea sapinii De Wild.  
Discorea sativa Munro  
Discorea vulgaris Miq.  
Elephantodon eburnea (Lour.) Salisb.  
Polynome alata (L.) Salisb.  
Dioscorea alata L. is an accepted name The Plant List

Other vernacular names
ASSAMESE: Kath alu.
BENGALI: Bengo nari, Chupri alu, Kham alu.
BURMESE: Myauk uu ni, Taw myauk uu.
CHINESE: Mao shu, Shen shu, Da shu.
FIJIAN: Uvi.
FRENCH: Igname ailée, Grande igname, Igname franche, Igname blanche.
HAWAIIAN: Uhi.
HINDI: Chupri alu, Khamalu.
INDIA: Ratalu.
INDONESIAN: Uwi, Huwi.
JAPANESE: Beniimo, Daijo, Daiyo.
KANNDA: Tuna genasu.
LAOTIAN: Houo.
MALAYALAM: Kachil.
MARATHI: Kondfal.
MEXICAN: Iñame, Ñame, Ñangate.
NEPALESE:Ghara tarul, Kukur tarul.
NIGERIA: Ji, Ji abana, Isu ewura.
PORTUGUESE: Inhame da India.
RUSSIAN: Dioskoreia alata, Dioscoreia krylataia, Iams belyi, Iams krylatyi.
SPANISH: Ñame comun, Ñame grande, Ñame alado, Ñame de agua, Ñame asiatico, Tabena.
TAMIL: Rasa vakku kilangu.
THAI: Man, Man bak hep, Man liam, Man sao, Noi.
VIETNAMESE: Khoai mo, Cam kenh, Co sa, Cu cai, Cu canh, Khoai trut, Khoai vac, Man ham.

Botany
Dioscorea alata is slender creeping vine reaching a length of several meters. The leaf-stalk slightly purple at both points of attachment. Tubers are usually bright lavender in color, occasionally white. Root is tumorous, often with small axillary tubers.

Distribution
- Throughout the Philippines in thickets at low and medium altitudes.
- Cultivated.

Constituents
- Main component are complex carbohydrates.
- Tuber yields 1-4% protein, very low fat, and high fiber content.

- Yam tuber yields per 100 g: calories 118 kcal (494 kJ)., carbohydrates 27.89 g, protein 1.53 g, fat 0.17g, fiber 4.1g, vitamin C 17.1mg, thiamine (vitamin B1) 0.11 mg, riboflavin (vit B2) (0.03 mg), niacin (vit B3) 0.55 mg, pantothenic acid 0.31 mg, pyridoxine (vit B6) 0.29 mg, folate 23 mcg, calcium 17 mg, vitamin K 2.3 µg, magnesium 21 mg, phosphorus 55mg, sodium 9 mg, potassium 816, iron 0.54 mg, zinc 0.24 mg, copper 0.18, selenium 0.70 mcg, water 69.60 g. (17) (19)
- Study of 20 varieties of Dioscorea alata yielded total dietary fiber (TDF) ranging from 4.10 to 11.00%, dry matter composition 19.10 to 33.80%, amylose 27.90 to 32.30%. Mineral content in mg/kg(-1) showed zinc 10.10 to 17.60, potassium 10,550-20,000, Na 83-131, Ca 260-535, and Mg 390-595. (see study below) (18)

Properties
- Considered cholagogue, antispasmodic, diuretic.
- Studies have suggested antioxidant, estrogenic, cholesterol lowering, hypolipidemic, hepatoprotective, nephroprotective properties.

- Caution: High potassium content suggests caution in use by patients with renal disease.

Parts utilized
Tubers

Uses
Nutrition / Edibility
- Tuber is eaten as vegetable.
- Tubers are rich in B vitamins, especially thiamine and niacin.
Folkloric
- Powdered tubers used as a remedy for piles, gonorrhea, and applied externally to sores.
- In Assam, tuber paste applied on cancerous wounds; used for leprosy, gonorrhea, skin diseases and high blood pressure. (1
5)
- Used to treat diarrhea, frequent urination, cough, diabetes mellitus, burns and scalds.
- In traditional Chinese medicine, used to treat diarrhea, fortify the spleen and kidneys.
- Used to relieve dysmenorrhea.

Studies
Antioxidant Activity:
• Local Root Crops as Antioxidant: A 2006 study of commonly consumed roots crops in the Philippines (Kamote, Ipomoea batata; ubi, purple yam, Dioscorea alata; cassava, Manihot esculenta; taro or gabi, Colocasia esculenta; carrot, Daucus carota; yacon (Smallanthus sonchifolius) showed them to be rich sources of phenolic compounds with antioxidant activity, highest in sweet potato, followed by taro, potato, purple yam and lowest in the carrot. • Study showed hyperhomocysteinemia induced by methionine could be reversed by D alata feeding. D alata feeding showed antioxidative effects.
Anti-Fenton Reaction Activity / Copper-chelating and absorbing capability:
Study of three taxa of D alata showed significant anti-Fenton reaction activity, similar to EDTA. Study showed copper-chelating and absorbing capability of yam tuber pulp. (1)
• Bowel function benefits:
Study showed 25% to 59% yam diet increased fecal mass and SCFA (short-chain fatty acid) output, modulated fecal microflora and thickened caecal mucosal lining in mice. (3)
• GI function / Antioxidant: Rhizome extract of DA has been shown to possess radical scavenging activity. Study showed both Chinese yam and Japanese yam were beneficial for intestinal health and oxidation prevention. (4)
• Estrogenic activity: Extract study isolated new and known compounds and showed activation of estrogen receptors alpha and beta. Results suggest beneficial effect of yam for menopausal women.
• Dioscorin / Angiotensin converting enzyme inhibition / Antihypertensive: Dioscorin, the tuber storage protein of yam and its hydrolysates presents potential use for hypertension control. (5)
• Cholesterol lowering: Study showed reducing effects of 50% yam diet on plasma and hepatic cholesterol levels probably through inflated fecal fat and steroid excretion. (6)
• Cytokine-Mimetic property: Study that from extracts of yam roots and leaves( D alata), taro roots (Colocasia esculenta), buyo leaf (Piper betle) showed strongly stimulated proliferation of both bone marrow cells and splenocytes, significantly increasing cell concentrations. (7)
• Disocorin / Cytokine Expression / TLR4-Signaling Pathway: TLR4 is a promising target for immunomodulating drugs and TLR4 agonists have therapeutic potential for treating immune diseases and cancer. Study shows dioscorin is a novel TLR4 activator and induces macrophage activation via TLR4-signaliing pathways.
• Estrogenic effect in menopausal women : In a study of menopausal women with rice staple diet replaced by yam (D alata) for 30 days showed improvement in status of sex hormones (estrone, sex hormone binding globulin, estradiol), blood lipids and antioxidants suggesting possible benefits in reducing breast cancer and cardiovascular disease in postmenopausal women. (8)
• Bone-Protective Effect: Yam prevented loss of BMD (bone mineral density) and improved calcium status without stimulating uterine hypertrophy in ovariectomized mice. TNG yam may be beneficial for postmenopausal women for preventing bone loss. (9)
• Hypo-Triglyceridemic Effect: Yam may inhibit the acute induction of hypertriglyceridemia and liver enlargement in rats fed a high cholesterol diet. (10)
• Renal Protective / Hepatoprotective: Pharmacologic and biochemical studies showed yam have both renal protective and hepatic fortification effects in acetaminophen rats. Results provide basis for the use of yam in traditional Chinese medicine for deficiencies of liver-yin and kidney-yin. (12)
• Potential Health and Nutritional Benefits: Study showed the potential use of D. alata as a functional food to supplement the fiber and mineral needs of consumers, and underlines the need to exploit its used in food fortifications and formulations. (see constituents above) (18)
• Attenuation of Renal Interstitial Cellular Fibrosis: Renal interstitial fibrosis is characterized by extracellular matrix (ECM) synthesis. Study evaluated the fibrosis regulatory effect of Dioscorea alata. Epithelial-mesenchymal transition (EMT) in kidneys is driven by regulated expression of fibrogenic cytokines such as transforming growth factor-beta (TGF-ß). Study suggests Dioscorea alata might act as a novel fibrosis antagonist, which acts partly by down regulating the TGF-ß/smad signaling pathway and modulation EMT expression. (
20)
• Antioxidant / Flavonoid Content: Study of methanol extract for total phenolics and flavonoid content yielded 0.68 g/100g and 1.21 g/100g, respectively. An ethanol extract showed strong DPPH radical scavenging activity. The maximum inhibitory concentration (IC50) in all models viz., DPPH, hydroxyl, superoxide, and ABTs radical cation scavenging activity of tuber were 27.16, 26.12, 30.65, and 25.53 µg/mL respectively at 1 µg/mL concentration. (
21)
• Antidiabetic: Study evaluated the antidiabetic effect of an ethanolic extract of D. alata in glucose loaded and alloxan induced diabetic rats. Results showed showed significant antidiabetic activity evidenced by a highly significant reduction (p<0.001) in blood glucose levels at doses of 100 and 200 mg/kg, respectively. (
23)
• Anti-Allergic: Study evaluated the effects of ethanol extract of tuber of D. alata on allergic models of mice induced by Ovalbumin using measurements of IgE, IL-4, and TNF-α level. EEDA dose of 0.62 and 1.24 g/kg was able to decrease the IgE level and EEDA dose of 1.24 g/kg was able to increase TNF-α levels. (
24)
• Immunostimulatory / Mucilages: Study evaluated purified mucilages from three Taiwanese yam cultivars to evaluated the immunostimulatory effects on murine innate and adaptive immunity. Results showed all three mucilages could elevate the number of T. helper cells in peripheral blood and enhance the phagocytic activity of granulocyte, monocytes, and macrophages, both ex vivo and in vitro tests. The production of specific anti-ovalbumin (OVA) antibody and OVA-stimulated splenic proliferation were all enhanced by all mucilage groups. Results suggested the tuber mucilage might function as an immunostimulatory substance. (
25)
• Protective Effect in Aniline-Induced Splenic Toxicity: Study evaluated the protective effects of ethanolic extract of D. alata on hematological and biochemical changes in aniline-induced spleen toxicity in rats. Results suggest the involvement of oxidative and nitrosative stress in aniline-induced splenic toxicity and DA protects the rats from toxicity, which may be due to its antioxidant property and the presence of different phytochemicals. (
26)

Availability
Widcrafted.

Godofredo U. Stuart Jr., M.D.

Last Update April 2016

Photos © Godofredo Stuart / StuartXchange

Additional Sources and Suggested Readings
(1)
Anti-Fenton reaction activity of three taxa of water yam (Dioscorea alata L.) / Tsu-Shing Wang et al /International journal of food science & technology ISSN 0950-5423 / 2007, vol. 42, no9, pp. 1107-1113
(2)
Local Root Crops as Antioxidant
(3)
Uncooked Taiwanese yam (Dioscorea alata L. cv. Tainung No. 2) beneficially modulated the large bowel function and faecal microflora in BALB/c mice
(4)
Effect of Yam (Dioscorea alata Compared to Dioscorea japonica) on Gastrointestinal Function and Antioxidant Activity in Mice / Journal of Food Science Vol 71 Issue 7, Pages S513 - S516 / 10.1111/j.1750-3841.2006.00113.x
(5)
Both dioscorin, the tuber storage protein of yam (Dioscorea alata cv. Tainong No. 1), and its peptic hydrolysates exhibited angiotensin converting enzyme inhibitory activities / Feng-Lin Hsu et al /Agric Food Chem. 2002 Oct 9;50(21):6109-13.
(6)
Effects of Taiwanese yam (Dioscorea alata L.) on the mucosal hydrolase activities and lipid metabolism in Balb/c mice /
Nutrition Research, Volume 23, Issue 6, Pages 791-801
(7)
Cytokine-Mimetic Properties of Some Philippine Food and Medicinal Plants / Journal of Medicinal Food / June 2007, 10(2): 290-299. doi:10.1089/jmf.2006.067.
(8)
Estrogenic Effect of Yam Ingestion in Healthy Postmenopausal Women / Journal of the American College of Nutrition, Vol. 24, No. 4, 235-243 (2005)

(7)
Dioscorin isolated from Dioscorea alata activates TLR4-signaling pathways and induces cytokine expression in macrophages / Shu-Ling Fu et al / Biochemical and Biophysical Research Communications
Volume 339, Issue 1, 6 January 2006, Pages 137-144 • doi:10.1016/j.bbrc.2005.11.005
(9)
The bone-protective effect of a Taiwanese yam (Dioscorea alata L. cv. Tainung No. 2) in ovariectomised female BALB/C mice / J Sci Food Agric 2009; 89: 517–522 / DOI 10.1002/jsfa.3489
(10)
YAM (DIOSCOREA ALATA) INHIBITS HYPERTRIGLYCERIDEMIA AND LIVER ENLARGEMENT IN RATS WITH HYPERCHOLESTEROL DIET / Yen-Hung Yeh et al / J Chin Med 18(1,2): 65-74, 2007
(11)
Chinese Yam (Dioscorea alata cv. Tainung No. 2) Feeding Exhibited Antioxidative Effects in Hyperhomocysteinemia Rats / Sue-Joan Chang et al / J. Agric. Food Chem., 2004, 52 (6), pp 1720–1725
DOI: 10.1021/jf0345954
(12)
Effects of "Chinese yam" on hepato-nephrotoxicity of acetaminophen rats / Shih-Chang Lee et al / Acta Pharmacol Sin . Jun 2002; 23 (6)
(13)
Dioscorea alata / Synonyms / The Plant List
(14)
Disocorea alata / Common names / Wikipedia
(15)
Food and medicinal values of certain species of Dioscorea with special reference to Assam / Barnali Dutta / Journal of Pharmacognosy and Phytochemistry 2015; 3(4): 15-18
(16)
Discorea alata / GlobInMed
(17)
Purple yam (Discorea alata) / BotanicalOnLine
(18)
Potential health benefits of water yam (Dioscorea alata) / Faustina Dufie WM, Oduro, Ellis WO, Asiedu R, Maziya-Dixon B. / Food Funct. 2013 Oct;4(10):1496-501. doi: 10.1039/c3fo60064e.
(19)
Dioscorea Alata / Nutritional Information / OnlyFOODS
(20)
Dioscorea alata Attenuates Renal Interstitial Cellular Fibrosis by Regulating Smad- and Epithelial-Mesenchymal Transition Signaling Pathways / Shu-Fen Liu, Shan-Yu Chang, Tao-Chen Lee, Lea-Yea Chuang, Jinn-Yuh Guh, Chien-Ya Hung, Tsung-Jen Hung, Yu-Ju Hung, Po-Yi Chen, Pei-fang Hsieh, Yu-Lin Yang / PLOS / http://dx.doi.org/10.1371/journal.pone.0047482
(21)
Total Phenolic, Flavonoid Contents and In vitro Antioxidant Activity of Dioscorea alata l. Tuber / G. Sakthidevi and V.R.Mohan* / J. Pharm. Sci. & Res. Vol.5(5), 2013, 115 - 119
(22)
Sorting Dioscorea names / /Maintained by: Michel H. Porcher / MULTILINGUAL MULTISCRIPT PLANT NAME DATABASE / Copyright © 1995 - 2020 / A Work in Progress. School of Agriculture and Food Systems. Faculty of Land & Food Resources. The Univers ity of Melbourne. Australia.
(23)
Antidiabetic activity of ethanolic extract of tubers of Dioscorea alata in alloxan induced diabetic rats
/ V Maithili, SP Dhanabal, S Mahendran, R Vadivelan / Indian Journal of Pharmacology, 2011, Vol 43, No 4, Pp 455-459.
(24)
ETHANOL EXTRACTS OF TUBERS DIOSCOREA ALATA L. AS ANTIALLERGIC AGENT ON MICE BALB/C INDUCED WITH OVALBUMIN / SRI NABAWIYATI NURUL MAKIYAH*, ZULKHAH NOOR, WIDODO, MUHAIMIN RIFA’I AND MOCH. SASMITO DJATI / Int J Pharm Bio Sci 2014 July; 5(3): pp 214 - 220
(25)
Immunostimulatory activities of yam tuber mucilages / Huey-Fang SHANG, Huey-Chuan CHENG, Hong-Jen LIANG, Hao-Yu LIU, Sin-Yie LIU, and Wen-Chi HOU* / Botanical Studies (2007) 48: 63-70.
(26)
Protective effects of Dioscorea Alata l. in aniline exposure-induced spleen toxicity in rats: A biochemical study / Reehan Khan, Aman B Upaganlawar, Chandrashekhar Upasani / Toxicology International, 2014, Vol 21, Issue 3, pp 294-299.
(27)






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