Diosgenin is a
steroidal saponin, which is extracted from the root of
Wild Yam (Dioscorea
villosa) and other species.
Dioscorea is a genus of flowering plants, and some Dioscorea species are known
and used as a source for the steroidal sapogenin diosgenin. Diosgenin is found
in several Dioscorea species and one Heterosmilax species, namely D.
zingiberensis, D. septemloba, D. collettii and H. yunnanensis.
Liver protection
Int Immunopharmacol. 2014. Protective effects of the total saponins
from Dioscorea nipponica Makino against carbon tetrachloride-induced liver
injury in mice through suppression of apoptosis and inflammation.
For a list of herbs used in Chinese medicine, see Chinese Herbs.
Dioscorea research studies
Antioxidant activity of dioscorea and dehydroepiandrosterone (DHEA) in older
humans.
Life Sci. 1996.
Araghiniknam M, Chung S, Nelson-White T, Eskelson C, Watson RR.
Arizona Prevention Center, University of Arizona, School of Medicine, Tucson
Dioscorea is a yam steroid extract used in commercial steroid synthesis and
consumed by people.
DHEA
is a steroid which declines with age, but without known
activity. This study was designed to determine whether dioscorea supplementation
could increase serum dehydroepiandrosterone sulfate (DHEAS) in humans and
modulate lipid levels in older people. The subjects were selected volunteers
aged 65-82 years. The serum DHEAS level, lipid peroxidation and lipid profile
were assessed. Three weeks of dioscorea supplementation had no affect on serum
DHEAS level. However DHEA intake of 85 mg/day increased serum DHEA levels
100.3%. DHEA and dioscorea significantly reduced serum lipid peroxidation,
lowered serum triglycerides, phospholipid and increased HDL levels. Both DHEA
and the steroid yam extract, dioscorea, have significant activities as
antioxidant to modify serum lipid levels.
Toxicology Int. 2014. Protective effects of dioscorea alata L. In aniline exposure-induced spleen toxicity in rats: a biochemical study.
Dioscorea alata (water yam) (Chinese yam)
Chinese yam (Dioscorea alata cv. Tainung No. 2) feeding exhibited
antioxidative effects in hyperhomocysteinemia rats.
J Agric Food Chem. 2004.
Antioxidative effects of Dioscorea alata (D. alata) were investigated in
hyperhomocysteinemia (HHcy) induced by methionine (Met) oral feeding (1 (g/kg of
BW)/day). These results indicated that HHcy induced by Met could be reversed by
Dioscorea alata feeding. Dioscorea alata feeding exhibited its antioxidative
effects in HHcy including alleviating PA, lipid peroxidation, and oxidative
stress, but did not induce activity of antioxidant enzymes which had already
adaptively increased by HHcy.
Both dioscorin, the tuber storage protein of yam (Dioscorea alata cv. Tainong
No. 1), and its peptic hydrolysates exhibited angiotensin converting enzyme
inhibitory activities.
J Agric Food Chem. 2002.
Dioscorin, the tuber storage protein of yam, was purified to homogeneity by DE-52 ion-exchange chromatography. This
purified dioscorin was shown by spectrophotometric methods to inhibit
angiotensin converting enzyme (ACE) in a dose-dependent manner (12.5-750 microg,
respectively, 20-62% inhibitions) using N-[3-(2-furyl)acryloyl]-Phe-Gly-Gly
(FAPGG) as substrates. The 50% inhibition (IC(50)) of ACE activity was 6 microM dioscorin (250 microg corresponding to 7.81 nmol) compared to that of
0.00781 microM (0.0095 nmol) for captopril. The commercial bovine serum albumin
and casein (bovine milk) showed less ACE inhibitory activity. The use of
qualitative TLC also showed dioscorin as ACE inhibitors. Dioscorin showed mixed
noncompetitive inhibitions against ACE; when 31.25 microg of dioscorin (0.8
microM) was added, the apparent inhibition constant (K(i)) was 2.738 microM.
Pepsin was used for dioscorin hydrolysis at 37 degrees C for different times. It
was found that the ACE inhibitory activity was increased from 51% to about
75% during 32 h hydrolysis. The smaller peptides were increased with increasing
pepsin hydrolytic times. Dioscorin and its hydrolysates might be a potential for
hypertension control when people consume yam tuber.
Effects of "Chinese yam" on hepato-nephrotoxicity of acetaminophen in rats.
Acta Pharmacol Sin. 2002.
To study the effect of yam in Taiwan, which is a commonly used Chinese
medicine, on hepato-nephro-toxicity in rats. Crude water extract of yam
(Dioscorea alata), was used to treat rats with an acute toxicity induced by
acetaminophen (APAP) challenge. The pharmacological and biochemical
studies showed the extract of yam had the effect of kidney secureness and liver
fortification. The pathologic sections showed good improvements in
renal tubular degranulation changes, necrosis and disintegration. The extract of
yam also possessed a good protection against the inflammation of central vein
and necrosis of liver tissue. The liver and kidneys are originated
from the same source. Pathologically, deficiency of the life essence in the
kidney may lead to the blood deficiency in the liver. The results showed that
the yam could prevent the damages of the liver and kidneys, thus preserving
their functions. This could b e the reason why the yam was commonly used in
traditional Chinese medicine, as seen in Liuwei Dihuang Wan be used in the case
of deficiency of liver-yin and kidney-yin.Antifungal properties of yam (Dioscorea alata) peel extract.
Folia Microbiol (Praha). 1996.
The extraction of natural antifungal compounds from the peels of yam (Dioscorea
alata) and the effect of these compounds on both the vegetative and reproductive
structures of some yam not pathogens were studied. Four prominent antifungal
components were obtained; one of the components was fully characterized and
identified as beta-sitosterol. The antifungal activity of the compounds toward
the germination of spores of two yam pathogens showed an inhibition of less than
57% at a concentration of 50 mg/L while inhibition on the elongation of
germ-tubes of Fusarium moniliforme was as high as 82% at the same concentration.
However, the ED50 for inhibition of germ-tube elongation in the yam compounds
for the same organism was below 32 mg/L. The role of the yam compounds at high
concentrations in disease resistance is discussed.
Nutritional assessment of yam (Dioscorea alata) tubers.
Plant Foods Hum Nutr. 1994.
The nutrient and antinutrient components of tubers from seven cultivars of
Dioscorea alata were determined. The average crude protein content of D. alata
tubers was 7.4%. Starch (75-84%) was the predominant fraction of the tuber
dry matter. Significant differences in crude protein and starch contents were
observed among cultivars. Vitamin C content of the yam tubers ranged from 13
to 24 mg/100 g fresh weight. The results showed yams to be reasonably good
sources of minerals. Phytic acid contents of the yams were low, with values
ranging from 58 to 198 mg/100 g dry matter. Total oxalate levels in yam
tubers were found to be in the range of 486-781 mg/100 g dry matter, but may not
constitute a nutritional concern since 50-75% of the oxalates were in the
water-soluble form. The overall results are suggestive of the nutritional
superiority of yams compared to other tropical root crops.
Dioscorea batatas
Yam (Dioscorea batatas) tuber mucilage exhibited antioxidant activities in
vitro.
Planta Med. 2002.
The yam (Dioscorea batatas Decne) tuber mucilage (YTM) was extracted and
partially purified by SDS and heating treatments. These results suggest that
mucilage of yam tuber might play roles as antiradicals and antioxidants.
Antioxidant activities of dioscorin, the storage protein of yam (Dioscorea
batatas Decne) tuber.
J Agric Food Chem. 2001.
Dioscorin, the storage protein of yam (Dioscorea batatas Decne) tuber (which
is different from dioscorine found in tubers of Dioscorea hirsuta), was
purified. It is suggested that 32 kDa dioscorin, the storage protein of yam
tuber, may play a role as antioxidant in tubers and may be beneficial for health
when people take it as a food additive or consume yam tubers.
Dioscorin, the major tuber storage protein of yam (Dioscorea batatas decne)
with carbonic anhydrase and trypsin inhibitor activities.
J Agric Food Chem. 1999.
Dioscorin, the tuber storage protein of yam (Dioscorea batatas Decne), was
purified successively.
Dioscorea bulbifera
[Anticancer effects of various fractions extracted from Dioscorea bulbifera on
mice bearing HepA]
Zhongguo Zhong Yao Za Zhi. 2004.
To investigate the anti-cancer activities and the possible
mechanism of Chinese herb Dioscrea bulbifera. The herb was extracted
sequentially with petroleum ether, ethanol and water. The anticancer screen were
carried out in vivo with HepA in mice. The inhibitory effects on the
formation of ascites volume and HepA cell viability in ascites were found in
those extracted fractions except water fraction, the petroleum ether fraction
being the strongest. Life span of mice bearing HepA ascites was prolonged after
exposed to 100 mg x kg(-1) petroleum ether fraction and shortened after exposed
to water fraction significantly. Besides, abnormal microstructure on HepA cells
surface was found and it was supposed to be potential effect against viability
of HepA which was convinced with the regeneration of HepA cells from ascites in
mice exposed to petroleum ether fraction. Anticancer active
compounds are mainly extracted by petroleum ether from hydrophobic constituents
of Dioscrea bulbifera and the anticancer effects were related to direct toxicity
on tumor cell.
Experimental pathological study of subacute intoxication by Dioscorea
bulbifera
Fa Yi Xue Za Zhi. 2003.
To study the pathological change and the toxic mechanism of Dioscorea bulbifera in mice. Sixty ICR mice were randomly assigned to
four groups poisoned respectively with 200% Dioscorea bulbifera L of 1/4 LD50,
1/10LD50, 1/30LD50 and a control group treated with distilled water by oral
administration. All animals were pathologically examined with LM and some of
them were examined with TEM when the mice died during the experiment or the
survival mice were sacrificed after thirty days. The pathological
changes showed fatty change and the increasing glycogen of liver cells;
degeneration and necrosis of the epithelia of uriniferous tubules. The serum BUN
and ALT of the experimental groups mice were higher than that of control group.
Enzyme histochemical staining showed the decreasing activity of G-6-P and SDH in
the liver cells in the experimental groups. The experiment suggests
that the target organs were liver and kidney. The toxic mechanism of Dioscorea
bublifera L was the damage of the mitochondrional and endoplasmic reticulum
membrane directly. As a result, the activity of the SDH and G-6-P decreased, the
metabolism was affected.
Antitumor-promoting constituents from Dioscorea bulbifera in JB6 mouse
epidermal cells.
Biol Pharm Bull. 20023.
An antitumor-promoting effect was found in the extracts/ingredients of a
plant used as a traditional medicine in mainland China, using the neoplastic
transformation assay of mouse epidermal JB6 cell lines. The ethyl acetate
soluble fraction of 75% ethanol extract of the rhizomes of Dioscorea bulbifera showed an inhibitory effect against the tumor promotion of JB6 (Cl 22 and Cl
41) cells induced by a promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA).
Further investigation on the constituents of the EtOAc fraction from the
rhizomes revealed the chemical structure to be kaempferol-3,5-dimethyl ether
(1), caryatin (2), (+)-catechin (3), myricetin (4),
quercetin-3-O-galactopyranoside (5), myricetin-3-O-galactopyranoside (6),
myricetin-3-O-glucopyranoside (7) and diosbulbin B (8). Constituent antitumor-promoting
activities were also examined in the same way. Compounds 1-7, characterized as
flavonoids with the two hydroxyl groups at C-7 and C-4', showed the most potent
inhibitory effect, but there seemed to be differences in the inhibitory effect
between flavonol aglycones and flavonol glycosides. Compared with epicatechin, catechin exhibited much stronger inhibitory activity which suggested that
chemical stereo structures of compounds affect the efficiency of inhibition.
Compound 8 showed moderate activity. The constituents with antitumor-promoting
activity from this plant are reported for the first time.
Dioscorea dumetorum
Pharmacological evaluation of Dioscorea dumetorum tuber used in traditional
antidiabetic therapy.
J Ethnopharmacol. 1986.
This study was undertaken to confirm or otherwise disprove the alleged
effectiveness of Dioscorea dumetorum tuber in the traditional treatment of
clinical diabetes mellitus. Hydroalcoholic extracts of the tuber were
fractionated by precipitation or solvent partition and the various extracts or
fractions subjected to phytochemical and pharmacological tests. Whereas the
alkaloid-containing fraction was hyperglycaemic in fasting normal mice, the
whole extract and the fractions containing steroidal derivatives evinced
significant hypoglycaemic activities in fasting normal mice or rabbits and in
fasting alloxan-diabetic rabbits. The hypoglycaemic action of the glycosidic
portion in particular was prompt and potent, in normal as well as in severely
alloxan-diabetic rabbits suggesting thereby the possibility of obtaining an
agent that could act in conditions of even severe insulin lack.
Dioscorea villosa
The effects of sustained delivery of diosgenin on the adrenal gland of female
rats.
Biomed Sci Instrum. 2003.
University of Mississippi Medical Center, Jackson, MS
Diosgenin has been reported to have tremendous medical applications. In
addition, as an herbal extract it appears to be free of any major adverse
effects. Recently, Wild Yam has been used to minimize post-menopausal symptoms
and is sold unregulated over the counter at a variety of pharmacy and health
food stores. The specific objectives of this study were to continuously deliver
diosgenin to adult ovariectomized female rats for 45 days and follow changes in
body weight, organ weight and histopathological changes in the adrenal gland.
Adult female Sprague Dawley rats were divided into three equal groups (n = 54,
250-300 gm BW). Rats in group I served as the control group, animals in group II
were ovariectomized and animals in group II were ovariectomized, and
supplemented with tricalcium phosphate (TCP) drug delivery system loaded with
500 mg diosgenin. The results indicated that ovariectomized animals had a
significant increase in body weight and spleen weights. Slight increases in wet
adrenal weights were observed in the ovariectomized group compared to the
control animals. Histopathological evaluation of the adrenal gland revealed an
increase in the cortical and medullary adrenal areas of the ovariectomized group
and a significant decrease in these areas in the diosgenin treated animals. The information is considered important because reduction in adrenal
mass may poses a potential for major endocrine complications.
Effects of wild yam extract on menopausal symptoms, lipids and sex hormones
in healthy menopausal women.
Climacteric. 2001 Jun.
Baker Medical Research Institute, St Kilda Central, Melbourne Victoria,
Australia.
Many women seek alternatives to hormonal therapies for the
management of menopausal symptoms. Among the treatments currently popular are
extracts of wild yam (Dioscorea villosa), which are applied topically in the
form of a cream. These preparations are known to contain steroidal saponins,
including diosgenin, which has been claimed to influence endogenous
steroidogenesis. However, there have been no studies of the safety or efficacy
of these preparations in the management of menopausal symptoms. We
therefore conducted a double-blind, placebo-controlled, cross-over study of the
effects of a wild yam cream in 23 healthy women suffering from troublesome
symptoms of the menopause. After a 4-week baseline period, each woman was given
active cream and matching placebo for 3 months in random order. Diaries were
completed over the baseline period and for 1 week each month thereafter, and
blood and saliva samples were collected at baseline and at 3 and 6 months, for
measurement of lipids and hormones. This study suggests that
short-term treatment with topical wild yam extract in women suffering from
menopausal symptoms is free of side-effects, but appears to have little effect
on menopausal symptoms. It emphasizes the importance of careful study of
treatments for menopausal symptoms if women are to be adequately informed about
the choices available to them.
Dioscorea panthaica
Steroidal saponins from Dioscorea panthaica and their cytotoxic activity.
Pharmazie. 2004.
A new steroidal saponin, dioscoreside E (1), and a known compound,
protodioscin (2), were isolated from an ethanol extract of the rhizomes of
Dioscorea panthaica. Compounds 1 and 2 showed cytotoxic activity against a panel of tumor cell lines.
Dioscorea tokoro
Methanol extract of Dioscoreae Rhizoma inhibits pro-inflammatory cytokines
and mediators in the synoviocytes of rheumatoid arthritis.
Int Immunopharmacol. 2004.
Dioscoreae Rhizoma (MDR), the root of Dioscorea tokoro MAKINO, has been used
for the treatment of arthritis, muscular pain and urinary diseases in oriental
medicine. The present work evaluates a methanol extract of Dioscoreae Rhizoma. MDR did not show any cytotoxic effect on mouse lung fibroblast cells (mLFCs) or
human fibroblast-like synovial cells (hFLSCs). However, it significantly reduced
the proliferation of hFLSCs stimulated by interleukin-1beta (IL-1beta) and tumor
necrosis factor-alpha (TNF-alpha). MDR significantly inhibited the production of
TNF-alpha and IL-1beta as well as down-regulating the expression of
cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in IL-1beta-
and TNF-alpha-stimulated hFLSCs. MDR also effectively reduced the level of
reactive oxygen species (ROS) in these cells. Taken together, these findings
provide evidence that MDR may be a candidate for the treatment of rheumatoid
arthritis (RA).
Rehmannia Endurance - With Dioscorea
Planetary Formulas
Planetary Formulas Rehmannia Endurance is based on the classic Chinese tonifer
Rehmannia Six: Liu Wei Di Huang Wan, one of the most strengthening tonics of
Chinese herbalism. Traditionally it was used for those who are tired and run
down from overwork and inadequate rest due to a fast paced-lifestyle.
Supplement Facts:
Calcium 128 mg
Rehmannia Root 320 mg
Poria Cocos Sclerotium
160 mg
Tree Peony Root Bark 160
mg
Dioscorea Root 160 mg
Alisma Rhizome 160 mg
He Shou Wu Root (Fo Ti) 80
mg
Chrysanthemum
Flower 64 mg
Ligustrum Seed 64 mg
Saw Palmetto Berry 48 mg
Lycii Fruit Extract 40 mg
also known as goji berry and available as a supplement.
Cornus Fruit 18 mg
A number of diocorea species have been researched
including:
villosa
dioscorea bulbifera
elephantipes
compositae dioscorea
D batatas
alata
dioscorea opposita