|
Botany
A slender creeping
vine reaching a length of several meters. The leaf-stalk slightly
purple at both points of attachment. Root is tumorous, often
with small axillary tubers.
Distribution
Throughout the
Philippines in thickets at low and medium altitudes.
Cultivated.
Parts utilized
and preparation
Tubers
Graphic insert
Tuber, 16" long.
Uses
Nutrition
Tuber is eaten as vegetable
Folkloric
Powdered tubers used as
a remedy for piles, gonorrhea, and applied externally to sores.
Studies
• Antioxidant Activity (1) 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 acitivity, highest in sweet potato, followed by taro, potato,
purple yam and lowest in the carrot. (2) 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.
• 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.
• 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.
• 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.
• Cholesterol lowering: Study
showed reducing leffects of 50% yam diet on plasma and hepatic cholesterol
levels probably through inflated fecal fat and steroid excretion.
• 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.
• 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 iinduces 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.
• Bone-Protective Effect: Yam prevented loss of BMD (bone mineral density) and improved calcium status without stimulating uteriine hypertrophy in ovariectomized mice. TNG yam may be beneficial for postmenopausal women for preventing bone loss.
• Hypo-Triglyceridemic Effect: Yam may inhibit the acute induction of hypertriglyceridemia and liver enlargement in rats fed a high cholesterol diet.
• 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.
Availability
Widcrafted.
|
